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NATURAL HISTORY
SURVEY
me
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ILLINOIS NATURAL HISTORY SURVEY
SS
Bulletin
Contents and Index
Volume 27
1957-1961
STATE OF ILLINOIS
DEPARTMENT OF REGISTRATION AND EDUCATION
NATURAL ah SURVEY DIVISION THE LIBRARY QF Ti
Urbana, Illinois ;
ior ore
any me #13
SeATE OF ILLINOIS
DEPARTMENT OF REGISTRATION AND EDUCATION
heer uURAL HISTORY SURVEY DIVISTON
ILLINOIS
NATURAL HISTORY SURVEY
Bulletin
Volume 27
1957-1961
Printed by Authority of the State of Illinois
CR BANA, LELIN OLS
-”
1
45 As oe
2
(88859—500—3-64) GB 2
CONTENTS
We bieLeE. 1—ECOLOGICAL LIFE HASTORY OF THE WARMOUTH
(CENTRARCHIDAE). By R. Wetpon Larimore. August, 1957. 83 pp., color
PEPELINE LSU aeD PARLE OSA ry Rte tert ce oder ceed oeah eee hare atacand oye seid Meee tore ria Beenie a dene 1-83
Acknowledgments 2, Areas of intensive study 2, Habitat characteristics 6, Food
habits 10, Reproduction 30, Growth 49, Parasitism 64, Behavior 66, Economic rela-
tions 69, Summary 76, Literature cited 80
ARTICLE 2—A CENTURY OF BIOLOGICAL RESEARCH. By Hartow
B. Miiis, Greorce C. Decker, HErBert H. Ross, J. CEpric CARTER, GEORGE
W. Bennett, THomas G. Scott, JAMEs S. AyArs, RuTH R. Warrick, and BEs-
ste B. Bast. December, 1958. 150 pp., 2 frontis.; 23 illustrations. ........... 85-234
FroM 1853 TO 1958 85, Natural History Society 86, State Laboratory of Natural His-
tory 87, State Entomologist 88, Natural History Survey 98, The future 101; Economic
Entomo.ocy 104, Early history 104, Practical problems and progress 106, Biological
control 120, Value of insect control 123, Emphasis for the future 124; FAUNIsTIC SuR-
veys 127, Early background 127, Changing habitats 128, Periods of faunistic activi-
ties 128, Research collections 134, Faunistic reports 135, Retrospect and prospect 144;
APPLIED BOTANY AND PLANT PATHOLOGY 145, Early activities 146, Recent activities
149, Past and present 160, Unsolved problems 160, Future possibilities 161; AQuaric
BioLocy 163, Beginning of aquatic ecology 163, First field laboratory 165, Fishes and
plankton 166, The Fishes of Illinois 167, Illinois River plankton 167, Bottom fauna
168, New lines of research 169, Early management attempts 170, Modern management
170, The last twenty years 172, Direction of future studies 177; WILDLIFE RESEARCH
179, Development 179, Organization 181, Research contributions 183, Wildlife man-
agement 198, The future 199; PusBLicaTIONS AND PusLic RELATIONS 202, Early publi-
cations 203, Publications series 205, Editorial personnel 207, Public relations 208,
Editorial policy 208; Liprary 210, The library at Normal 210, The library at Ur-
bana 210, Library collections 211, Library personnel 213, Financial support 213;
FoRMER TECHNICAL EMPLOYEES 215; LITERATURE CITED 219
ARTICLE 3—LEAD POISONING AS A MORTALITY FACTOR IN WA-
TERFOWL POPULATIONS. By Frank C. BELtrosz. May, 1959. 54 pp.,
ETT EMME Seay MTS a oi wee, Aol aes tet ctey ose ke ny Sees Sega A WE Sone HES Lite, we, Bye: ee LO OS
Acknowledgments 236, Lead poisoning die-offs 236, Availability of lead 249, Ingested
lead shot in migrating ducks 254, Lead in wild mallards dosed and released 269,
Preventing lead poisoning 276, Discussion 279, Summary 283, Literature cited 287
ARTICLE 4—FOOD HABITS OF MIGRATORY DUCKS IN ILLINOIS.
By Harry G. ANpeErSON. August, 1959. 56 pp., frontis., 18 figs.............289-344
Acknowledgments 289, Study procedure 290, Foods of various species 292, Plant foods
323, Animal foods 337, Grit 340, Lead shot 342, Summary 343, Literature cited 344
ARTICLE 5.—HOOK-AND-LINE CATCH IN FERTILIZED AND UNFER-
TILIZED PONDS. By Donatp F. HANsEN, Georce W. BENNETT, ROBERT J.
Wess, and JoHn M. Lewis. August, 1960. 46 pp., frontis., 11 figs........... 345-90
Acknowledgments 345, Experimental ponds and their watersheds 346, Experimental
procedures 353, Pond fertilization and plant life 356, Pond fertilization and fishing
success 358, Pond fertilization and standing crops 376, Standing crops and fishing suc-
cess 380, Field fertilization and fishing success 383, Economics of pond fertilization
385, Anglers’ evaluation of ponds 386, Summary 387, Literature cited 389
ARTICLE 6—SEX RATIOS AND AGE RATIOS IN NORTH AMERICAN
DUCKS. By Frank C. BELLRosE, THomas G. Scott, ARTHUR S. HAWKINS,
and Jessop B. Low. August, 1961. 84 pp., 2 frontis., 23 figs................0¢ 391-474
Acknowledgments and sources of data 391, Sex ratios 392, Age ratios 430, Summary
468, Literature cited 471
INDEX
The index was prepared by the Section of Publications and Public Relations
and printed by authority of the State of Illinois, IRS Ch. 127, Par. 58.12.
EMENDATIONS
Page 15, column 1, line 21 of text matter. For Phyrganeidae substitute Phryganeidae.
Page 18, table 9. For Hydrochnellae substitute Hydrachnellae.
Page 135, column 2, line 4 from bottom. For Mitchell, substitute Mitchill.
Page 215, column 1, line below Apple, James Wilbur. For Entomologist, 1943-1949 substitute
Entomologist, 1942-1949.
Page 296, table +; page 299, table 7; page 319, table 32; page 338, table 39. For Belastomatidae
substitute Belostomatidae.
Page 323, column 1, line 7 (boldface head). For Greater Scaup substitute Common Goldeneye.
(Corrected in most copies.)
Page 326, line 16 from bottom. For Leguminosae substitute Leguminosae.
Page 439, column 1, line 21. For as single hens of male-female pairs substitute as single hens
or male-female pairs.
Page 448, table 55, line 1. For five substitute six.
The following paragraph is from a letter dated December 1, 1959, from W. L. McAtee, for
many years with the U. S. Department of Agriculture and the U. S. Fish and Wildlife Service.
It may serve as a supplement to Volume 27, Article 2, in that it adds to the list of articles on
Stephen Alfred Forbes.
“Two papers of mine relating to Forbes not mentioned in the bibliography are an obituary
(Auk, July 1930, pp. 453-454), in which I say that he founded the modern science of economic
ornithology, and some paragraphs from a chapter ‘Economic Ornithology’ in Fifty Years’ Prog-
ress of American Ornithology 1883-1933 (A.O.U., Lancaster, Pa., 1933, pp. 111-29), elaborating
on that appraisement.”
ILLINOIS NATURAL HISTORY SURVEY
Bulle ti 171 Printed by Authority of ce
the State of Illinois
ene
de> a
Ecological Life History
of the Warmouth
(Centrarchidae)
R. WELDON LARIMORE
STATE OF ILLINOIS e WutiaM G. Srratton, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION e Hartow B. Mus, Chief
abba Al EN
OCT 2b i954 HISTORY S!
ILLINOIS NATURAL HISTORY SURVEY
Bulletin
i 27, Article 1 cE
piume i Printed by Authority of
August, 1957 the State of Illinois
Ecological Life History
of the Warmouth
(Centrarchidae)
me WEEDON: LARIMORE
STATE OF ILLINOIS e Wutt14M G. Stratton, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION e Hartow B. Mitts, Chief
Urbana Illinois
STATE OF ILLINOIS
Wiruram G. Srratron, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
Vera M. Binks, Director
BOARD OF NATURAL RESOURCES AND CONSERVATION
Vera M. Binks, Chairman; A. E. Emerson, Ph.D., Biology; L. H. Tirrany, Ph.D., Forestry; Waiter H. Newnouse,
Ph.D., Geology; Rocer Apams, Ph.D., D.Sc., Chemistry; Roperr H. Anperson, B.S.C.E., Engineering; W. L.
Everitt, E.E., Ph.D., Representing the President of the University of Illinois; Detyte W. Morris, Ph.D., Presi-
dent of Southern Illinois University
NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois
SCIENTIFIC AND TECHNICAL STAFF
Hariow B. Mitts, Ph.D., Chief
Bessie B. East, M.S., Assistant to the Chief
Section of Economic Entomology
Georce C. Decker, Ph.D., Entomologist and Head
J. H. Biccer, M.S., Entomologist
L. L. Encuisu, Ph.D., Entomologist
S. C. Cuanpier, B.S., Associate Entomologist
Wiruis N. Bruce, Ph.D., Associate Entomologist
Norman Gannon, Ph.D., Associate Entomologist
W. H. Lucxmann, Ph.D., Associate Entomologist
Joun D. Briccs, Ph.D., Associate Entomologist
Ronatp H. Meyer, M.S., Assistant Entomologist
Ropert SNetsiIncER, M.S., Field Assistant
Joun P. Kramer, M.S., Laboratory Assistant
Eucene M. Bravi, M.S., Research Assistant
Ricuarp B. Dysart, B.S., Technical Assistant
Apert Saraxo, B.S., Technical Assistant
Eart StapEvuacHeER, B.S., Technical Assistant
Suz E. Watkins, Technical Assistant
H. B. Perry, Ph.D., Extension Specialist in Entomology*
Stevenson Moore, III, Ph.D., Extension Specialist in
Entomology*
H. B. Cunnincuam, M.S., Research Associate*
Joun W. Marrteson, M.S., Research Associate*
Crarence E. Wuirte, B.S., Research Assistant*
Joun Artruur Lowe, B.S., Research Assistant*
Cuartes Le Sar, B.S., Research Assistant*
Loutse Zincrone, B.S., Research Assistant*
Mary E. Mann, R.N., Research Assistant*
Section of Faunistic Surveys and Insect Identification
H. H. Ross, Ph.D., Systematic Entomologist and Head
Mitton W. Sanperson, Ph.D., Taxonomist
Lewis J. Srannarp, Jr., Ph.D., Associate Taxonomist
Puiurre W. Smiru, Ph.D., Associate Taxonomist
Leonora K. Guioyp, M.S., Assistant Taxonomist
R. B. Sevanper, Ph.D., Assistant Taxonomist
Epwarp L. Mocxrorp, M.S., Technical Assistant
Tueitma H. Overstreet, Technical Assistant
Section of Aquatic Biology
Georce W. Bennett, Ph.D., Aquatic Biologist and Head
Wiruiam C. Starrett, Ph.D., Aquatic Biologist
R. W. Larimore, Ph.D., Associate Aquatic Biologist
Davin H. Buck, Ph.D., Associate Aquatic Biologist
Rosert C. Hittipran, Ph.D., Associate Biochemist
Donatp F. Hansen, Ph.D., Assistant Aquatic Biologist
Joun C. Cratrey, B.S., Field Assistant
Crarence O. Stevenson, B.S., Field Assistant
Rosert D. Crompton, Field Assistant
Section of Aquatic Biology—continued
Maurice A. Wuiracre, M.A., Assistant Aquatic
Biologist*
Witu1am F. Cuivpers, M.S., Technical Assistant*
Arnotp W. Frirz, B.S., Field Assistant*
Ricuarp E. Bass, Field Assistant*
Pau Frey, B.S., Laboratory Assistant*
Section of Applied Botany and Plant Pathology
J. Cepric Carter, Ph.D., Plant Pathologist and Head
J. L. Forsserc, Ph.D., Plant Pathologist
G. H. Borwe, M.S., Associate Botanist
Rosert A. Evers, Ph.D., Associate Botanist
R. J. Campana, Ph.D., Associate Plant Pathologist
Joun M. Ferris, Ph.D., Assistant Plant Pathologist
Rosert Dan NeeEty, Ph.D., Assistant Plant Pathologist
E. B. Himenricx, M.S., Assistant Plant Pathologist
Rovenia F. Firz-Gerarp, B.A., Technical Assistant
James D. Birsrucx, M.S., Research Assistant*
Section of Wildlife Research
T. G. Scott, Ph.D., Game Specialist and Head
Rateu E. Yeartter, Ph.D., Game Specialist
Cart O. Monr, Ph.D., Game Specialist
F. C. Be.irose, B.S., Game Specialist
Ricuarp R. Graser, Ph.D., Associate Wildlife Specialist
W. R. Hanson, Ph.D., Assistant Game Specialist
H. C. Hanson, M.S., Assistant Game Specialist
Frances D. Rossins, B.A., Technical Assistant
Vircinta A. Lancpon, Technical Assistant
Howarp Crum, Jr., Field Assistant
Jack A. Exuis, M.S., Field Assistant*
Ronatp Lasisxy, M.S., Field Assistant*
Rexrorp D. Lorp, D.Sc., Project Leader*
FrepERIcK GREELEY, Ph.D., Project Leader*
Guen C. Sanpverson, M.A., Project Leader*
Paut A. Vous, Jr., B.S., Project Leader*
Section of Publications and Public Relations
James S. Ayars, B.S., Technical Editor and Head
BiancHe P. Younc, B.A., Assistant Technical Editor
Wiiuram E. Crark, Assistant Technical Photographer
Witiiram D. Woon, B:S., Technical Assistant
Technical Library
Rut R. Warrick, B.S., B.S.L.S., Technical Librarian
Net Mites, M.S., B.S.L.S., Assistant Technical
Librarian
CONSULTANTS: Herretorocy, Hosart M. Smirn, Ph.D., Associate Professor of Zoology, University of Illinois;
Parasirotocy, Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University
of Illinois; Witp.tire Researcu, Wiitarp D. Kuimstra, Ph.D., Associate Professor of Zoology and Director of
Co-operative Wildlife Research, Southern Illinois University.
*Employed on co-operative projects with one of several agencies: Illinois Agricultura] Extension Service, Illinois
Department of Conservation, United States Army Surgeon General’s Office, United States Department of Agriculture,
United States Fish and Wildlife Service, United States Public Health Service, and others.
This paper is a contribution from the Section of Aquatic Biology.
(56723—5,500—5-57) cn eae 2
CONTENTS
MIAME EI OET LGN (Saya tpn c eek es Secs, GS eA erat ty we sa Bd Mere Bey ke ae stn 2
SIN TEN SLY Be OE UD Yo 2 ac» accra blac abin-s guehind’s lie’ o icon ce teal e ns Boa bode 2
Fae RA RMMECASTA (Tes crete ie. Gite lee aco uae wax cy seed ithe Oe ae ELS eck Milles 5 ieee! Oy ae? 4
earn me beet bee crevasse th areas eA PS eae DEI Ee ee SOR not AEM a Eee SS 5
Meera GEMS EE SICA CT ER ES TICS cs chu tie cial ais is-e GD bow kan Scigs FA Sawa ie aio cae ao cinee ta s 6
PeEarE ON Mand sOttOnl: VUAtETIAlS) 3 .cMae bi: % Gas fe decsteoma cars ain, sem a bec cate 6
REET Cae cerca ainh See Ate: auaveee oe shank Gites Bisrects Sime aM ver GS Wenn Conteh A ne eA 7
asap RNs at cra et eran nano esd BA ord Dre tr Nan eval tac te ee ee aN 8
erie Orer Cen were eet crate ge cote ate Cis a cia eee etd Sak oe eh ed ee 2
ence PTOULETIER Ai Olen ote cate tN ot Re fy as ee) ne es Vil ae 10
aM TREE MEN IS er GOS esky ess Rachel 2 fo,cvallahe hie carte russe athe ls Pe us. Geahensimodls De ata weenie a nS: 10
ELBIT \DCUSS "Ge whet UIC eR eR ey a ae oe es lb CR ee 10
Me A OOds: ily Lk WOdl ADIEAES et fe a js 45/4, oe eck oe ela dane Ae 14
Feta gtr ac) Pee he, oPesevoie «caer ds otal 2 1d a Soke ews Cid Noa ns ovis Mee el eee 14
Reena ieme le RCIA tol tre Sia NR a chew tn ahs Cia untd shah a Se BVA es ic Oe EE 15
pee PN IMMUN Tee TAS 8 ee Me oh ehsci w Yo alsin or gate «ae eh Orava HL Aa vet Ry WS ahh eh ERAS TE res, 20
RN REN EC Mee ee gh e cc Rae Vidz st Tena casera So ose ht ca ho, ae ueleale Saar tate, elas rans av ae Ree 21
ral Pm NIMES acre Vege: Shae cold Ge aide vigrameneen fsa ts Soong aula epee 22
SEN CRUST 0? pc RO em AN Rae NN Pe ER aes eo a DR Sag eh Ra Ye So 23
IB EAN a Scab inlh dulce tone MaN Petts nt RCE De a ee VST ae PLO yea PUR th eR LSS, 23
[tele ol CATE TOT ETON Ds is Sars ete 0 cence a aera pra ee OR ON ha ada 26
Maree RCRD S PASTA ia ki utc Ach: t's Wacko Naess ew sis ana C4 Elie abe peat ae Me 27
EES CMTC ORS OMINSE CLELOIN oslo: cht, ie sat wid, Neg ROU letas op scecshe, whia'y see DANE aR a 28
Bracna oe onelnstons omeHood: habits. «cc sce sae es 34 6k ope aeind ws cothareeereme 29
ERECT) CHT Aah ae NO CE Sas, SR A te PP on at ge PR RO MR 5 BOE ie 30
Arena it we tene me E MOGUELS etc. 5, ciskaca (ee an os See eh tet raw oe ae Ses oe Ree 31
MCE erie Aa ey Clem natn i shite ee te act led aie Ubsceys a laivedva Svat eeaede ieee 31
LPR aT aaa eg ga ely 20 ce gee et RAV nOe, Aare ee) Rae ge EP OEY FO te NP 30
Se Tea reve mene 1OP MONA ws. die ats at ees Sateen sce vcpahe wed alabama thane aed Lae ee 39
emiestl cages ume COLVICLES covncta Nc waa Hace tes MOC ate a ctvarels oooh G. arseniere wane & OE Haak aces Uetiees 39
acarionrandy OAnSeCuerionr Or INESES.c.5 5 csi os wets oe sees Sead ch sally be Mae 39
Reece MINTY SOUT SIND aya cel sitet.) < oie is salle svne coun oles oR eho Cetin Mint
Fae eerie a Peo ee cage ie eh TAU Rp nda oe Seles =a Stra eld Gh es. aon Do alee dee 43
mizesane: Ace rat OExuall IWlatunity./: 2... Joe ass cc aoee eid «Deedee vedios laces 43
Petes Bie etme ST Sei Thee ee Ne sight le rtte sh iy dc vas wishin Svlaids Soom «oe aman eo le 43
Weposition-and-Mertilizationcat Bees, .iik osc od us dase e eee ba luslew en hewns 43
elise hiay ay Heel CUA OS CAA del Le ee a) scrawl 1h Aloe 4 Sirs, e-h wl Siw cess teh ose alal a abaiubane hats 45
Wevelopmernt tos. MamlryOs ices Pee ie Pee Aes 4 se ale sce ahicta be wre Cac BAe oh alae 45
Development and-Growetl Of Larvae... ibs. -s eke eae bees eeee ssh weveeas 47
ISEB BOP To Ml WS ce Tole Cs a oe PR A See: SR OME i ae 48
AEROS) MANLECEIE IDE VAY ANS acs Aimee ste ety wets dle Ae aurdpie, no alee Pec Mee wus 49
CHELLIS Gg RRS i ERDAS OE PNT cea Iv ee a Ae es US a DR 49
Pee enuIncre GrrUwibie rte pre. hte AA tac nate Pid aah so wn MM aM ed bee 49
elation: Orjboay-Growtl £0 ocaleMGrowth: f/ceg 2 ienaak ded aca hs kano a eons 49
Relatiomot Bady Growemto ) ail (Growth)..: 5 256s oon toe 0h so caoalea < 50
Relation of Growth in Length to Growth in Weight..................... 50
Se rciem bette Oita Liierner: tat eeers gk chedahs re. Saleen alate as bgeeele Ga lbe oles Reba 51
Beale Micthod wt Calenlating Grow flies. os ccpe c.. cdie sce ole saath wite wavs ele were 52
Walidiiy ot stherAmmnulustasea= Wear Vath. c...6s 0s ness ob ame me gelatin alana. 52
Chamevensticsnon ation A mmulis..6 tae eo tk. S40 ais Set cin no os mee Sea nae ee ee 53
Meine car a MMS OUIPIEHION ts, pci faiaid cee sce-sloGon eels e « 2G ae cea pede bes 54
LEG CTeTATAI MIDI ES Gobir Sch y O99 OO nn eS RO ea ee 54
Growth In Park: Pond... si oo. cic Sie cos eke ce cteciell er one 5 im tin anata 55
Collection and Preparation of ‘Materials... ...'. 0... 2... 6.2.0. eee 55
Growth Differences Between Sexes...... 80.0050 s. 003 os vs ee 56
History of Successive Year Classes. . 0.020.) nese e os tise 56
Fluctuations in: Annual Growth: .!<. 005 /60).00 06 ea esa oe 58
Seasonal Growth. foo. i6.o. heel a. eee . Ta 59
Growth in Localized Population... ::.2. 2... 5...2:.:.+./ 272 eee 60
Compensatory “Growth...........0 0.00 4200420000. Aes es oe 60
Sizes and Longevity << . iso. 0.5. -0 264. Janae eS. 0 te er 62
Growth in Venard Dake: :... 05. ..000 ce cn ete howe we wane 62
Growth in Other Water Areas..........-...----- viva: bn bide re 62
PARASTTISNE 2 ce Coir tee a Oia Le La EOE lai Ss Pale ee 64
PERTLAVIOR oa ba voc his Toa ee eR a ns LL Dek ee weg en eS Sere err 66
General Activity and Disposition. <1... 000.00 00. oe aa Si er 66
Reproductive Behavior.:.....2..... 56S e. 0% 0) ie ee 66
Defense of the Nest Area.../.... 0205100. .aee be hcl eo 66
Synchronization: ¢:. 2.4.4.5. 2... s ste bee b ews bel Gk oo eee 67
Orientation vc 562 bo ek ee seb bc oe oooh ie wens tee ee ee 67
Persmasion vies cede 2c bales dius enebantndsage ses eee 67
The spawnmp Actes). 6.2 eo ee ee eee 67
Reproductive Isolation......5...).00..5.c)ea bees oe 2s) er 67
Parental Cate: 6450 cect. 6. oaks oSabed: bo oa eee eee 67
Group’ Behavior’ 2... 655 ted cies hp 0 eS ee a ae oe 68
AGPTERATIONS. cs 226 oes be ts 248 hee ylelas oi eyed Ons oie Oar 68
Phierarenye. fo oee foes le bo has, eaa)s Rob ote ee ee 68
Feeding *Behaviot si... 622 285 Se OG en dle eo Palle wis ino bo ae 68
MAT TUG bs oo is ax oreo xen ee ce Ae wi eed S hetag ahd Stam aheaid ee Ce er 68
BPeonomic. RELATIONS. 2.02505. SoG. Peon ae Bree ee le Pe 69
The Warmouth ‘as:a. Food: Fish. . o.oo. 0 ede oe eee eee 69
‘The Warmouth as a Sport, Fish... . 022042005. .2025.%. 36 os a 69
‘The Warmouth as a Laboratory Fish.....4... 2022005 22..22 425 see 71
The Warmouth in Artificially Established Populations........................ 71
Experimental Species: Combinations.:.....2..2. 66.0. .805 settee oe 72
General Conclusions About Species Combinations.............-.-..++--++- 76
SAT MART ARY Seg ics Fu carota Saeed & Side Ski e 4A] AR Saree the Dolce et oe ee 76
LITERATURE: (CITED A. 3 ees ee oe hn hee eed oe eee 80
os Ss es
> SI
f=
eS
WARMOUTH
Maynard Reece
Ecological Life History of the
Warmouth (Centrarchidae)
VERPOPULATION among cer-
() warm-water fishes is now com-
monly recognized as a cause of
poor fishing in many lakes and ponds of
the United States. More than a decade
ago, Bennett (1944:186) suggested that
perhaps some sunfish not prone to overpop-
ulation would, with little control by man,
produce good fishing over a prolonged pe-
riod. This suggestion stimulated a search
for a species that has a low reproductive
potential, a species that does not tend to
overcrowd its habitat, and yet has good
sporting qualities. The warmouth, Chaeno-
bryttus gulosus (Cuvier), appeared to be
such a species. The study of its life history
and ecology presented here may serve as a
basis for an estimate of the potential value
of the species as a companion for bass or
other game fishes in lakes and ponds of [Ili-
nois and neighboring states.
The warmouth is a dark, thick-bodied
sunfish (family Centrarchidae) which su-
perficially resembles the somewhat bet-
ter known rock bass, 4 mbloplites rupestris
(Rafinesque). It is readily distinguished
from the latter by the presence of three
spines in the anal fin; the rock bass has six.
A good color and morphometric description
of the warmouth is given by Forbes &
Richardson (1920: 245).
The nomenclature of this robust sunfish
was summarized by Jordan, Evermann, &
Clark (1930:302-3), in whose check-list
Chaenobryttus gulosus was the accepted
name. Harper (1942:50) pointed out that
Bartram in his Travels, 1791, had accu-
rately described this species and called it
Cyprinus coronarius, a name which ante-
dates Chaenobryttus gulosus by 38 years.
Recently, however, the Committee on No-
menclature of the American Society of
Ichthyologists and Herpetologists agreed
that, because Bartram was not consistently
binomial in the work cited by Harper, the
name Chaenobryttus gulosus should be re-
applied (Bailey 1956: 336). Of the 16
R. WELDON _ LARTMOR-:E
or more common names given to the spe-
cies, warmouth, warmouth bass, and gog-
gle-eye are the most widely known. The
American Fisheries Society Committee on
Common and Scientific Names of Fishes
(1948:16) designates this fish the war-
mouth, the name used throughout this
paper.
The warmouth occurs generally in suit-
able waters throughout the central and
eastern United States and south to the
Gulf Coast. Its distribution extends from
Kansas and Iowa to the Mississippi River
drainage in southern Wisconsin, includes
the southern two-thirds of the Lower Pen-
insula of Michigan, Lake Erie, and the
Allegheny River tributaries of Pennsyl-
vania, and embraces the territory south-
ward to Florida and west through the
Gulf states to the Rio Grande (Hubbs &
Lagler 1947:93). As a result of intro-
ductions, it is now found west of the
Rocky Mountains. Introductions into Cali-
fornia, Washington, and Idaho were made
as early as the end of the last century
(Smith 1896: 441).
In Illinois, the warmouth has a wide,
scattered distribution. Approximately a
half century ago, Forbes & Richardson
(1920: 246) found it in glacial lakes of
northeastern I[|linois and showed that it in-
creased in abundance from north to south;
they gave it frequency ratios in their col-
lections for northern, central, and south-
ern sections of the state as 0.44, 0.78, and
1.78, respectively.
Leonard Durham, while employed by
the Illinois Department of Conservation
in 1950-1955, found a somewhat different
pattern of warmouth distribution (unpub-
lished data). In studying representative
populations of fish in 426 Illinois ponds
and lakes, some of them natural and some
artificial impoundments, Durham found
little difference in the frequency of occur-
rence of warmouths in the three zones of
the state then recognized by the Depart-
C1]
2 Ittinors NATURAL HIsTory Survey BULLETIN
ment of Conservation. In the northern,
central, and southern zones, warmouths
were taken from 15.4, 17.1, and 15.4 per
cent, respectively, of the waters sampled.
These figures suggest that the distribution
of warmouths in Illinois may have changed
since Forbes and Richardson made their
collections. The construction of many arti-
ficial impoundments requiring the wide-
spread transportation of fishes for stocking
purposes probably is responsible for some
of the changes that have occurred in the
distribution of this species.
Although principally a pond and lake
fish, the warmouth occurs in the Rock,
Mississippi, and Illinois rivers and is re-
ported as common in small, sluggish
streams of the southern part of the state.
Its scattered distribution in Illinois coin-
cides with the occurrence of suitable habi-
tat.
ACKNOWLEDGMENTS
The research upon which this paper is
based was a project of the Illinois Nat-
ural History Survey and was proposed and
supervised by Dr. George W. Bennett,
who gave guidance and help in all stages of
the work.
Much of the material presented here
was included in a thesis submitted in
partial fulfillment of the requirements for
the degree of Doctor of Philosophy in the
Horace H. Rackham School of Graduate
Studies of the University of Michigan,
1950. As chairman of my doctoral com-
mittee there in the Department of Zool-
ogy, Dr. Karl F. Lagler directed my
graduate studies, made many suggestions
for my research, and helped me revise my
thesis manuscript.
The paper published here was edited by
Mr. James S. Ayars, the Natural History
Survey’s Technical Editor. His skill and
patience have added considerably to the
accuracy and clarity of reasoning, expres-
sion, and composition. Mrs. Darlene Ose,
while secretary in the Section of Aquatic
Biology, read and criticized the manu-
script.
Dr. Leonard Durham, while employed
by the Illinois Natural History Survey
from April, 1947, to August, 1950, as-
sisted in all of the field work and in many
of the laboratory preparations; his con-
Vol. 27, Art. 1
tinued interest added greatly to the com-
pleteness of this study and to the pleasure
of conducting it. Mr. W. Leslie Burger,
also while employed by the Natural His-
tory Survey, helped sort the contents of
warmouth stomachs, after which members
of the Section of Faunistic Surveys and
Insect Identification of the Natural His-
tory Survey identified many of the inverte-
brate food items. Messrs. William J.
Harth, James F. Opsahl, and William F.
Childers, while with the Department of
Conservation, assisted in some of the field
work or in the tabulation of data. Other
members of the Survey staff and my wife,
Glenn E. Larimore, gave willing aid to
the work.
I appreciate the permission to refer to
unpublished observations by members of
the Natural History Survey staff on war-
mouths in Illinois; observations of special
value are those by Dr. Bennett at Ridge
Lake, in Coles County, and at the Polly-
wog Association water area, in Vermilion
County, and those by Dr. Donald F. Han-
sen at Lake Glendale, in Pope County.
Credit for these and other unpublished ob-
servations is given in the text of this paper.
The Associated Tackle Manufacturers
supplied certain equipment necessary for
field work and gave financial support for
my library studies at the University of
Michigan.
The owners of several Illinois ponds in
which warmouths were studied aided this
investigation through their willing co-op-
eration.
The picture of the warmouth repro-
duced as the frontispiece was painted by
Mr. Maynard Reece and is used here
through the courtesy of the Iowa State
Conservation Commission.
AREAS OF INTENSIVE STUDY
As part of the investigation reported
here, intensive studies of warmouths were
conducted in two aquatic habitats, Park
Pond and Venard Lake, figs. 1 and 2;
these studies were then compared with
more general observations on warmouths
in other waters.
Both of the aquatic habitats in which the
intensive studies were conducted were
man-made: a flooded stripmine area and a
small artificial lake. The many differ-
August, 1957 LarimoreE: Lire History oF THE WARMOUTH 3
Fig. 1—Southwest section of Park Pond, Vermilion County.
Fig. 2.—Part of Venard Lake (principally the east arm), McLean County.
ences between these two water areas per-
mitted an evaluation of the effects of a con-
siderable range of habitat conditions on
warmouth populations.
Park Pond
Park Pond: has a history that dates back
many years. More than a quarter century
ago, in Vermilion County, in east-central
Illinois, an abandoned stripmine flooded
with waters from the Salt Fork River was
ILLinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 1
water level was raised by the two small
dams, lined the water’s edge.
The chemical composition of the water
differed from that of many other Illinois
lakes, primarily in its high mineral content,
table 1. Sulfates were especially high in
concentration, but the buffer effect of other
substances eliminated the extreme acidity
often associated with the sulfur of mine
waters.
The fish fauna of Park Pond had been
derived from two sources. Many species
Table 1—Chemical composition (parts per million) of water from Duck Pond, in the Polly-
wog Association area, Vermilion County, Illinois, and from five recently constructed United
States Soil Conservation Service ponds in central Illinois.
Iron MerTHYL ine
: Na ORANGE
Ponp Fil- | Unfil- Ca Mg and K SO, NO, Cl ALKA- Harp-
tered | tered LINITY NESS
Duck Pond
Joly: 05, 193822556 OLD] TAB’ 38.22) 4872 236701; 9.0) eae0 152.0 343.5
Duck Pond
October 7, 1942.... 0.1 | 58.8 | 44.6 3.5 | 33.0 146.0 329.0
Five Soil Conserva-
tion Service ponds
(average) August-
September, 1939...| 1.1 2.78) 26.9 | 15.1 TG e2. 2.0] 2.8 130.8 127.1
leased by a group of sportsmen and con-
servationists, who, in about 1929, had
formed the Waste Land Reclamation As-
sociation. In 1932, this area was acquired
by a group of sportsmen who had formed
the Pollywog Association, an organization
that has continued since that time to use
the area for hunting and fishing. A few
years after the formation of the Pollywog
Association, the construction of two small
dams raised the water level several feet.
A major part of the investigation reported
here was based on material from Park
Pond, which in 1946 had an area of 18
acres, in the central part of the Pollywog
Association area.
When field work for the warmouth
study was begun in 1946, the old mining
cuts from which coal had been taken in
1889 and 1890 had become filled with
water and appeared as irregular lakes con-
nected by many narrow channels, fig. 1.
High banks, formed when soil was re-
moved to expose underlying coal beds, had
become covered with dense brush and
small trees. Older trees, killed when the
of fish had entered on flood waters from
the nearby Salt Fork River. Fish of some
of these species, as well as others not in-
digenous to the Salt Fork, had been placed
in the pond by the Illinois Department of
Conservation. Thirty-six species were re-
corded from this pond, table 2.
The relative abundance of these species
was disclosed by the poisoning of the fish
populations in four ponds of the Pollywog
Association; each of these ponds was iso-
lated from other waters except during
floods. The total area to which poison was
applied equaled 9.07 acres and was sup-
porting a fish population which averaged
455.5 pounds per acre. Gizzard shad, carp,
and bluegills comprised high percentages
of the total weight of all fish collected
from these four ponds, table 3. War-
mouths represented 1.1, 0.9, 1.5, and 10.4
per cent of the weight in the four areas,
or 1.6 per cent of the combined weight of
fish from these waters. They made up a
greater proportion of the weight of the fish
population in these waters of the Pollywog
Association than in most other Illinois
August, 1957
Table 2.—List of fishes collected from Park
mation on the relative abundance of each kind.*
Larimore: Lire History oF THE WARMOUTH 5
Pond of the Pollywog Association, with infor-
SPECIES
RELATIVE ABUNDANCE
Peazardanad. Derosoma cepedianum (ie Sueuf): 02. cscs. ee ae De ve be beeen
Mn lerckceatpsucker,Carpiodes Cyprinus (Ise Sueur). «sc. csi ou eee cae eee ee hn ape
MimtemuckerGatostomus commersont (acepede).. cok ee es ot ee ee ce be cede aceabdatns
eeemmncnCKer Mit yzon sucéiia (liaCepede).wh, o. 6... keeles be ce be ele ose bere tess alee
Spotted sucker, Menvirema melanops (Ratinesque).... 0.2.02. ..-5-6+. 0.0: eect esa veceass
Piiversedhotse, Moxostoma anisurum.(Ratinesque).:. 20.3.5. 000600 2 ee cc a cn ees
Northern redhorse, Moxostoma aureolum (We Sueur)... 202 debs ee vs dn eh Lele eee
Carp, Cyprinus carpio Linnaeus. .
Bluntnose minnow, Pimephales notatus Ee se hehe ee OT Pe ae
Fathead minnow, Pimephales promelas Rafinesque. .
Golden shiner, Notemigonus crysoleucas (Mitchill).. . CS Cay nr am canrt gee ae ahd
Pdeueicatisn, (ofaiurws. punciains (RARMESQUE) oc. gos we oye nt bc pce ec doe cele me
Yellow bullhead, [ctalurus natalis De ae oats oie Spare rita:
Black bullhead, /ctalurus melas (Rafinesque) .
Flathead catfish, Pylodictis olivaris (Rafinesque).. PUA NO at A Ee Rtn GO
Madtom, Noturus sp..
Grass pickerel, Esox vermiculatus Le Sueur. .
American eel, Anguilla rostrata (Le Sueur)... ...
Banded killifish, Fundulus diaphanus (Le Sueur).
Blackstripe topminnow, Fundulus notatus (Rafinesque) . Se Bae ad sees
Yellow bass, Roccus mississippiensis (Jordan & Eigenmann). See tity Rt aE Be
Yellow perch, Perca flavescens (Mitchill)
Mere Pcriia caprodes (Ratiesque) 0+. 7.2.6 a cone ced snensiuspocees..4luserens
Johnny darter, Etheostoma nigrum Rafinesque. .. .
Smallmouth: bass, Micropierus, dolomtent Lacépéde...: 0.0.0 soe cc ve vee es
epotted Dass, Micropterus punctulatus (Rafinesque)....2. 004.0... 5... 2 eee ee ees
iearpemouth bass Mzcroprerus salmoiaes (hacépede).: .. 4.2252... 2 cso es sae es
Mrmontuere nurnorryitns- eulosus (Cuvier)... s\ 0h .4 os. dee ce ook ce we hs eee
Pereccolsuniichs /epom1s cyancius, Rafnesque. ox 0.05.5 6.0.20 s 2 eben ev eve ilec es
En picinsecd. Lepomis e1brosus (LADNACUS) we vec ee es Feb es one on ws
Bluegill, Lepomis macrochirus Rafinesque. ....
Orangespotted sunfish, Lepomis humilis (Girard).
Longear sunfish, Lepomis meg tlotis (Rafinesque). .
White crappie, Pomoxis annularis (RamMeESCUee eee a ee ane SAS ORE yee
Bieckerappie... umoxts maromaculatus (Ie Sueur): ict... de ee Seg ee be hw el
Brook silverside, Labidesthes sicculus (Cope)................
_. Abundant
.Common
.Common
_Rare
~Common
..Rare
.Common
.. Abundant
_Rare
_.Rare
Common
-Common
Abundant
..Common
.. Rare
; .. Rare
..Common
..Rare
_...Common
_. Abundant
..Common
_. Rare
_Rare
... Rare
_. Rare
: ..Rare
...Common
...Common
.. Common
_...Common
_. Abundant
_...Common
_.. Abundant
_. Abundant
.Common
..Common
*The common names used here and elsewhere in this paper follow those of the American Fisheries Society Special
Publication Number 1,
names are those given by Bailey 1956.
waters from which fish collections have
been taken in recent years.
Venard Lake
Little is known of the early history of
Venard Lake, fig. 2, an “‘old” artificial im-
poundment 1 mile south of Bloomington,
near the junction of state highway 51
and United States highway 66, in Mc-
Lean County, Illinois. In 1947, the lake
had an area of 3.2 acres. Though there was
a small spring at the upper end of the lake,
most of the water came from surface run-
off flowing into the lake from two shallow
valleys. Settling basins, built in both of
these valleys above the lake, removed much
of the silt load carried by surface water;
1948, or the changes recommended by the Society (Bailey 1952,
LOSS
most of the scientific
even so, during a period of several decades,
the basin had accumulated much silt. In
1946, the lake was drained, a stunted fish
population removed, and the basin allowed
to refill with water. In April of 1947,
Venard Lake was stocked with the follow-
ing fishes: 225 yearling largemouth bass
between 4 and 8 inches in total length, 15
largemouth bass between 9.6 and 13.7
(average 11.9) inches in total length, and
101 warmouths between 5.1 and 8.1 (aver-
age 6.8) inches in total length.
Extremely large broods of both bass and
warmouths were spawned in 1947. The
fish placed in the lake early in 1947 grew
well and supported excellent fishing the
following months. Many warmouths of
the 1947 year class were caught in spring
6 Ittrno1is NaTuRAL History SurRvEY BULLETIN
Table 3.—Kinds of fish that were collected
from four Pollywog Association water areas
treated with rotenone and the percentage of
the total weight of fish comprised by each kind.
The total area of water treated was 9.07 acres
and the average standing crop of fish was 455
pounds per acre.*
Per CENT OF
Kinp or FisH ToraL WEIGHT
Largemouth bass........
White crappie... 20... . -
BelGep Tibet om as eons e =o
Warwiguthr iat ee:
Othertine fish... 15 = 2,
RB ALAS rcs ees eet,
(Coatseish: occ cca Le
Gizzard:shads.!.. 22.532
Other forage fish.........
_
erm
KHWMnDOOD ON
Ss SCONCE WW
S
IMG] TH einen? Pint 8 AE SOP She
~
S
*Data from three of the water areas were collected by
Dr. George W. Bennett. Data from the fourth, Park
Pond, were collected by the author.
fishing of 1949, but very few were taken
in the summer of that year. Most of the
bass caught in 1949 were of the 1947
year class; many of them were still below
the then legal size of 10 inches.
During several weeks in August of
1948, shallow parts of the lake were
dredged. This operation killed many of
the 1948 brood of warmouths, in particu-
lar those trapped in the large weed masses
removed from the lake. The bass, on the
other hand, were apparently unharmed.
HABITAT CHARACTERISTICS
Collections of the warmouth from many
lakes, ponds, and streams of Illinois, and
descriptions of the water areas in which
this sunfish is found in other parts of its
range, indicate that it is usually associated
with certain habitat characteristics.
Vegetation and Bottom Materials
Dense weed beds and a soft bottom are
two habitat characteristics with which the
warmouth is usually associated. Brush and
roots attract this sunfish, and in water
areas lacking extensive weed beds, as in
some of the bottomland lakes of the South,
old tree stumps constitute the common hid-
ing places of the warmouth (thus, the
name “‘stump-knocker” is sometimes given
Vol. 27, Art. 1
to it). The quiet, almost sulky disposi-
tion of the warmouth and the customary
association of this fish (particularly young
and moderate-sized individuals) with pro-
tected hiding places cause members of this
species to concentrate in weedy and stump-
filled waters.
In the Everglades region of southern
Florida, Bangham (1939:263—-5) found
warmouths second in abundance to gars.
The waters were slow moving or still,
dark-colored, usually choked with vegeta-
tion, and with bottoms composed of soft
muck. Of five ponds in the Ocala National
Forest in Florida censused by Meehean
(1942), all contained warmouths, table 4.
The population having the greatest concen-
tration of warmouths was in an old pond
(Little Steep Pond) with a thick layer
of humus on the bottom and a mat of veg-
etation covering the entire surface. When
Tarzwell (1942) applied poison to three
backwater sloughs of Wheeler Reservoir
in Alabama, he found warmouths in all
populations, although in low percentages
by weight; the highest proportion of these
fish by weight (1.0 per cent) was asso-
ciated with a soft silt or mud bottom,
table 4.
The greatest proportion of warmouths
that Bennett (1943:360) encountered in
censusing 22 ponds and lakes of Illinois
was in Delta Pond (10.7 per cent war-
mouths by weight), table 4. As only 2
years had passed since this pond had been
stocked with game fish and pan fish, the
fish population probably ‘did not reflect the
environment of the pond as much as it did
the original stocking. Onized Lake, which
contained the second greatest proportion
of warmouths (6.5 per cent) that Bennett
found in a population, was an old pond
with heavy marginal vegetation that fa-
vored these fish. Warmouths in Onized
Lake may have been favored also by ex-
tremely heavy and selective fishing that
had resulted in the removal of large num-
‘bers of fish of other species.
The fish population in four shallow,
mud-bottomed backwater areas of the Mis-
sissippi River contained low percentages
of warmouths (Upper Mississippi River
Conservation Committee 1947:25—7 and
1948 :23-4). Two of the areas, near Sa-
vanna, Illinois, contained respectively 0.3
per cent and 1.0 per cent warmouths by
August, 1957
weight. The two other areas, near
Oquawka, Illinois, contained respectively
0.2 per cent and 1.4 per cent warmouths
by weight, table 4.
Turbidity
Forbes & Richardson (1920: 246) con-
cluded that the waters in which they found
the warmouth in their II]linois collections
indicated for this fish ‘‘a deliberate prefer-
ence for muddy water over pure.” Cer-
tainly the warmouth, now as in the time
of Forbes and Richardson, is found more
frequently and in greater abundance in
muddy or turbid waters, usually charac-
teristic of lowland lakes, backwater areas,
Table 4.—Data from fish censuses of 29 water areas containing warmouths:
Larimore: Lire History oF THE WARMOUTH 7
and sluggish streams, than in less turbid
waters.
However, the occurrence or abundance
of the warmouth in turbid waters may not
indicate a direct preference of this fish for
these waters. Rather, it may show that the
warmouth has a greater tolerance of turbid
waters and conditions associated with tur-
bidity than have most other sunfishes. This
tolerance may give the warmouth certain
advantages in a population in which it
must compete with many species and may
account for its frequently comprising
greater proportions of the total fish popu-
lation in turbid waters than in clear.
Turbidity may affect growth rate of and
fishing success for the warmouth. The
for each area
the approximate weight per acre of the standing crop of fish and the percentage of the total
weight comprised by warmouths.
< ae 48 &
g |esee| 2os
SA lees | See
Bopy or WaTER ea zEus Peleg Source or Dara
<< Bo an & Bes
bey ne, tw ms
es Rage = Ww 5
P ee a
Little Steep Pond ene 2.10 105 10.55 |Meehean 1942
First Pond (Florida). . 7.00 110 0.99
Big Prairie Lake (Florida). . 4.00 61 1.87
Buck Pond (Florida). . 18.00 33 6.61
Clearwater Lake (Florida). . 24.00 22 0.82
Upper Railroad Pond (Alabama). . 6.50 292 0.07 |Tarzwell 1942
Powerline Slough (Alabama). . 1.10 831 0.07
Sweetwater Slough (Alabama)... .. ol ah eae 4.40 188 1.00
Southside Country Club Lake :(Illincis). Sek aeoed 8.40 719 tr. Bennett 1943
Homewood Lake (Illinois). . ; 2.83 699 tr
Fork Lake (Illinois). . Me eee 1.38 53h) tr
Farmer City Golf Course Lake = (Llinois) aha SC 0.75 455 tr
Upper Twin Lake (Illinois). . sae eae. 1.08 392 tr
Black Jack Lake ea a 4.00 280 tr.
Delta Pond (Illinois). . 0.80 234 10.7
Onized Lake (Illinois). . 2.14 206 (0),
Duck Pond, Pollywog Assn. ‘(Illinois)... We Beet i 3.10 673 al
Triangle Pond, Pollywog Assn. (Illinois). eee 2.50 487 aS
Duck Island Farm Wake (llinois)s-e ae oer 4.90 316 tr.
Sportsmen’s Lake (Illinois).................... BETO 341 tr.
Lower Twin Lake (Illinois)................... 1.36 778 1.0
cake Glendale (Ilinois):.. ...... 02.008 nee. bee 82.00 86 5.0 pas unpub-
ished
Park Pond Slough, Pollywog Assn. (Illinois)..... 0.47 371 10.4 |Present study
Mississippi River Upper Mississippi
Been Bo ohare Stance) River Conservation
Area 1 ae 1.07 391 0.2 |Committee 1947,
Area a 1.76 695 1.4 1948
Backwaters, “Savanna (Illinois)
Slough 1.. eR of 2.16 171 0.3
Slough 2.. 0.95 423 1.0
Lamer’s Upper Pond (Illinois)... 0.25 516 4.7 ~|Elder & Lewis 1955
Lamer’s Lower Pond (Illinois). . 0.50+ 285 Seo
8 Intinois NaturAL History SurRvEY BULLETIN
best fishing for warmouths in experimental
areas of central Illinois is in moderately
clear water, the poorest fishing in tur-
bid waters. Jenkins, Elkins, & Finnell
(1955:42) found the slowest growing
Oklahoma warmouth populations in waters
known to be continuously turbid.
In a comparison of fish populations in
two southern Illinois ponds, one of which
was more turbid than the other, Elder &
Lewis (1955:394) reported that repro-
duction and the coefficient of condition of
warmouths was better in the less turbid
pond, although growth was somewhat bet-
ter for the warmouths in the more turbid
pond. As the two ponds differed in age,
size, density of fish population, and fertil-
ity, turbidity was not the only factor that
might have been responsible for differ-
ences in growth.
Depth
Several field observations indicate that
small warmouths remain in shallow weed
Vol. 27, Art. 1
beds, or other dense cover, for their food
and protection, whereas larger warmouths
spend more time in deeper water.
In Venard Lake, small warmouths were
collected in great numbers from the riprap-
ping along the dam, fig. 3, where they
were hiding beneath submerged rocks. Sel-
dom were large warmouths taken from
under these rocks; except during the
spawning season, most of the fish of larger
sizes were taken from deeper water.
Relatively few warmouths of desirable
sizes were found in a weed-choked channel
of Park Pond, although many large indi-
viduals were taken in Park Pond proper.
In Park Pond, winter collecting with an
electric shocker turned up large numbers
of small warmouths in shallow water close
to the banks, although at that time the sur-
face of the pond was covered with thin ice.
Apparently, small warmouths do not
leave their protected hiding places in shal-
low water even during cold weather. This
behavior contrasts sharply with that of
bluegills. Bluegills, most numerous of the
Fig. 3—Warmouths, stunned with an electric fish shocker, near the riprapping of the dam
at Venard Lake.
August, 1957
kinds of fishes collected along the banks of
Park Pond through summer months, were
taken there in far fewer numbers after
the beginning of cold weather. In the win-
ter, bluegills of all sizes were ordinarily
collected in compact schools in deeper
water. Large warmouths were likewise in
relatively deep water but showed little
tendency to group together. The conclu-
sions suggested here are that (1) war-
mouths of less than 5 inches total length
remain in protective cover in shallow water
the year around; (2) large individuals
spend more time in deep than in shallow
water; (3) warmouths exhibit no tendency
to group together during the winter
months.
Dissolved Oxygen
Observations in the field and laboratory
indicate that warmouths may survive in
habitats having low concentrations of dis-
solved oxygen. An example of the toler-
ance of warmouths for a low oxygen con-
centration was observed on April 27, 1947,
when 23 of 50 fish in an overcrowded
aquarium were found dead; of the 50 fish,
070
060
fe)
a
fo)
040
030
020
OXYGEN CONSUMED, CC./GM./HR.
2
ro)
.005
.000
Rae Ol oo MOAT
DISSOLVED OXYGEN, CC./L.
BP Ora
Fig. 4—Amounts of oxygen consumed (cubic
centimeters per gram per hour) by warmouths
in water of different oxygen tensions (cubic
centimeters per liter) at 20 degrees C.
Larimore: Lire History oF THE WARMOUTH 9
about half were warmouths and half were
bluegills. Of the 23 fish that were dead,
all were bluegills. The few bluegills that
were still living were light colored and
obviously sick. All warmouths, however,
were alive and showed very little or no
distress.
Warmouths are among the last species
of fish to die when collections of live fish
are concentrated in tanks, tubs, or buckets
containing water. For example, on No-
vember 12, 1949, between 9:30 a.m. and
2:15 p.M., many bluegills and warmouths
were taken alive from Park Pond. The
morning and afternoon collections were
placed in separate fish tanks in a truck.
No compressed air was supplied to the
water in these tanks, and consequently
many fish were dead when the tanks
reached the laboratory late in the after-
noon. In the tank containing the morn-
ing collection, all of the bluegills (about
30) were dead, whereas 40 warmouths in
the same container showed only mild signs
of distress. Of 50 bluegills collected in
the afternoon, only a few remained alive,
whereas 24 warmouths collected at the
same time and kept in the same tank were
in excellent condition.
In order to test the tolerance of war-
mouths for low concentrations of dissolved
oxygen, Leonard Durham and [I measured
the oxygen consumption of warmouths con-
fined in water containing different amounts
of this gas. Dr. C. L. Prosser, Professor
of Physiology, University of Illinois, sug-
gested the laboratory procedures for these
tests, the results of which supported our
observations made in the field.
The Winkler method was used to deter-
mine oxygen concentrations of two sam-
ples of water, one sample taken at the be-
ginning and one at the end°of the test
period. The difference between the two
samples in cubic centimeters of oxygen per
liter of water multiplied by the number of
liters of water in the test jar (volume of
jar minus volume of water displaced by
fish) gave the total amount of oxygen con-
sumed by the fish; the number of cubic cen-
timeters of oxygen used per gram of fish
per hour (cc./gm./hr.) was then calcu-
lated.
The amount of oxygen used by the test
warmouths in water at 20 degrees C.
ranged between 0.05 and 0.07 cc./gm./hr.
10 Ittrno1is NaturRAL History SurvEY BULLETIN
as long as the available dissolved oxygen
in the water exceeded 3 cc. per liter, fig. 4.
The consumption of oxygen by the war-
mouths dropped off abruptly from 0.03
cc./gm./hr. when the dissolved oxygen in
the water was 2.5 cc. per liter to less than
0.01 cc./gm./hr. when it was 0.5 cc. per
liter. The concentration of dissolved oxy-
gen at which oxygen consumption by the
fish declines abruptly is the critical oxygen
tension or the oxygen concentration at
which the metabolic rate of the fish begins
to fall off rapidly. Even though this crit-
ical oxygen tension is not lethal immediate-
ly it will ultimately be so. For the war-
mouths in our tests, the critical tension
figure was found to be 2.5 cc. per liter (3.6
p.p.m.) at 20 degrees C.
This critical tension figure is close to
that determined by Moore (1942:327)
after he had studied 13 species of fresh-
water fishes, including the largemouth
bass, the bluegill, the pumpkinseed, and
other species which are often associated
with the warmouth. Moore stated, “In
general, oxygen tensions of less than 3.5
p.p.m. at temperatures of 15-26° C. are
fatal within 24 hrs. to most of the species
tested.”
Although the warmouths in our tests
were removed before complete asphyxia- ,
tion, several specimens had reduced the
dissolved oxygen in the water to low con-
centrations. Only 0.21 cc. of oxygen per
liter of water remained at the end of one
test on warmouths, 0.24 cc. at the end of
another.
Conclusions from the tests described
above not only suggest reasons for survival
of the warmouth during periods of water
conditions that are generally considered un-
favorable to fish but also indicate certain
of the warmouth’s physiological character-
istics that are associated with its habitat
selection. Turbid waters, organic silt de-
posits, and dense vegetation, usually re-
garded as typical features of warmouth
habitats, are associated with high oxygen
demands and, at times, low concentrations
of dissolved oxygen.
Stream Gradient
The abundance of warmouths in flow-
ing waters appears to be related to stream
gradient; the occurrence of these fish in-
Vol. 27, Art. 1
creases from rare in fast-moving creeks to
common in sluggish streams with a low
gradient. I have collected warmouths in
several central Illinois streams having
gradients between 8 and 14 feet per mile,
but I have never collected them in large
numbers. Nelson (1876:37) mentioned
that Professor S. A. Forbes found this
species “very common” in the Illinois River
and tributaries through central Illinois;
and Forbes & Richardson (1920:246)
reported it “common” in southern Illinois,
“mainly in the smaller streams.” The IlIli-
nois River has a generally low gradient,
and the small streams of southern Illinois
in which warmouths are now commonly
reported have low gradients.
FOOD HABITS
The food habits of warmouths from
Park Pond and Venard Lake were studied
through a period of 12 months. The ob-
jectives of this study were to determine the
kinds and amounts of food consumed and
the ways in which food habits of the war-
mouths were influenced by habitat, season
of year, daily feeding periods, size of indi-
vidual fish, and competing species of fish.
Consideration was given to the possible ef-
fects of two different computing methods
on the interpretation of the data.
Methods of Study
For the food habits study, warmouths
were collected from Park Pond and Ven-
ard Lake, for the most part at monthly in-
tervals over a period beginning in October,
1948, and ending in September, 1949.
Heavy ice prevented collecting from Park
Pond in January and from Venard Lake
in January and February. Extra collec-
tions were taken from Park Pond during
the summer months as a means of deter-
mining diurnal feeding periods.
No attempt was made to measure the
relative abundance of food organisms in
the water areas.
A total of 515 warmouth stomachs were
collected from Park Pond; of these, 124
were empty and 391 contained food in
varying amounts. Of 413 warmouth stom-
achs taken at Venard Lake, 57 were empty
and 356 contained food materials in meas-
urable amounts.
August, 1957
All fish were taken with a rowboat fish
shocker (Larimore, Durham, & Bennett
1950), fig. 5. Regurgitation of food by the
fish was not caused by the shocker as it was
used in this study. While the fish’ were
fresh, their stomachs were removed and
LariMoreE: Lire History oF THE WARMOUTH 11
Survey. It was found to be convenient and
reliable. When items were measured by
both methods, the volume determined by
one method agreed closely with the volume
determined by the other. The sum of vol-
umes of the different kinds of food in each
Fig. 5.—An electric fish shocker being used from a rowboat to collect warmouths in Park Pond.
placed in cheesecloth bags; the bags were
labeled and placed in formalin. Other
parts of the digestive tracts were discarded.
In the laboratory, each stomach was first
studied as a unit. The contents were
removed and their total volume was meas-
ured. Then the contents were sorted
under a dissecting microscope (magnifi-
cation 9 to 48 times) into various taxo-
nomic categories, table 5. —The number of
individual organisms and the volume of
each kind of food were determined. Volu-
metric measurement was made by one of
two methods: large, irregular masses of
food were measured by water displacement
in a calibrated centrifuge tube; small,
compact items were measured by compari-
son with cork blocks of known volumes.
This second method was devised by the
late R. E. Richardson, for several years
employed by the Illinois Natural History
stomach was checked against the total vol-
ume recorded for each stomach when the
contents were removed.
After data for the sorted food materials
had been tabulated, calculations were
made that involved (1) the percentage of
stomachs in which each kind of food oc-
curred (frequency of occurrence), (2) the
average number of items of each kind of
food in the stomachs containing the food
(average number of items), (3) the aver-
age of the percentages of volume com-
prised by each of the kinds of food in each
of the stomachs examined (average of vol-
ume percentages), and (4) the percentage
of the total volume of all foods repre-
sented by each kind of food (percentage
of total volume). These calculations and
similar calculations for largemouth bass
used with the warmouths of Venard Lake
are summarized in tables 6-12.
12 Ittrnois NATURAL History SURVEY BULLETIN
Vol. 27, Art. 1
Table 5—Food organisms taken from the stomachs of 391 warmouths from Park Pond,
356 warmouths from Venard Lake, and 99 largemouth bass from Venard Lake; also, for each
kind of organism taken from the stomachs, its occurrence rating, based on the number of stom-
achs in which it was found: abundant (A), common (C), rare (R), or present but with no
record of abundance (X).
Foop ORGANISM
Cestoda
Proteotenhialidaey. civ liek oe pee eee eas Palo nea eee C ee
Bryozoa
Plgmnatellasspy Cone ica ee en ae SO ee
Annelida
MUR BOCH ACER. SeGiton S42 ti licg oc atte
Gastropoda
Planorbidae
Gyraulus apaab parvus gees
Ancylidae. . i
Ly mnaeidae. .
Physidae
Phosa integra Taldeman: 25.230 i 08th. ae =
Piysa probably: grime Says oveee oe we oes
Cladocera
Simocephalus sp..
Daphnia sp..
Chydorus (7) § spe
Alona (?) sp..
Copepoda
ENELADE SDs oe see eI ay tT EE n thg.
ORtACOd ater. se ee best th ea nie, eee ey tae
Amphipoda
Eygleila azleca (Saussure) o-2 io) fact yajen eee tk
Isopoda
Asellus sp..
Decapoda. .
Procambarus 's blandingii acutus (Girard). .
Orconectes virilis (Hagen)
Orconectes propinquus 5 propinguus ees ae
Araneae
AV COSID EL MN a eo ete Michele ce at ale Maun Wits erie Oe ale Rt enna e te ghar a eee a
Pisauridae
Dolomedes triton sexpunctatus Hentz...........
Hydrachnellae
Pimnesta faletda Woche ge Mes
LAAT ETL GUS SSP cftey hae tn ean Fo CE tS aL OR eae
Collembola
(Roduraaqualicg linnacus: same sok aes ee ee
Ephemeroptera
Caenis sp..
Siphlonurus sp..
Hexagenia limbata (Serville) . .
Odonata
_ Zygoptera. .
Argia apicalis (Say)...
Enallagma basidens Calvert...
E. carunculatum Morse. .
E. civile (Hagen). .
E. signatum (Hagen).
Ischnura posita (Hagen).
TI. verticalis (Say)..
Perithemis tenera ak Say).
ARISODEerals «ste te
Celithemis sp..
Epicordulia princeps (Hagen) ..
Erythemis simplicicollis (Say). Sit on ae
Leucorrhinia sp..
Libellula pulchella Drury.
Pachydiplax longipennis Berek Tet, aN
Park Ponp |
Warmouth
AMMO SP PLS
O
et Cento oO
“> Wad
VENARD LAKE
Warmouth Le
ass
R R
R
R
A
A A
R eso
R
R
A Cc
C Mer
R
A eh Ged
A A
x x
xX x
C C
A A
A A
A A
Rens oe
KE x
five x
A A
xX x
ye xX
x Dine
August, 1957 LarimoreE: Lire History oF THE WARMOUTH 13
Table 5—Continued.
Park Ponp VENARD LAKE
Foop ORGANISM
Warmouth Warmouth rea SE
Plathemis lydia (Drury).. 2 CIES CSM. | tak tae Pare tp ole A Lk Soh Cnn NO ad xX
Sympetrum obtrusum (Hagen). ; Ain Be Pada Aes ae ce aA Ry
Tetragoneuria sp.. EBs
Hemiptera
SOs Ae TNC pies es cash eala OS newer
HRCI TC AG ay aia ce aae ee titre Were a oh cte en eye Rees
Nepidae
I REN TICNTETS SIO) or tas ace PERT aE TT eee eee
Belostomatidae
IRVINE SOG og ROS ered cee ORO Fe
Veliidae
RVIDGRODHILGISD Mia fer ease es a eee es
RUEPRODATO. 3 obs bets oe hae a ree a ee
Gerridae
(QaA PS’ Soc wed Cece BO NCL OR at teach
Homoptera
‘esta NFACIGIEES Teese eked, cot ae aie ee a |
Neuroptera
SUSSBITINS. bBo b Oo eee oo ae ere eae eer a en R
Megaloptera
Sialidae
SHGIES SIDER AL OER eae dele era herd Aare CRS ee a
Hymenoptera
[POVAaRS LENE» sg Slee Beteiac as Brrr act Seen ae Ne
Apidae
AE ens MAMIACUS oe Oe Pan. os ade oe eae ew Ry a (hace vaneede ses
Coleoptera
Haliplidae
EASE OSS CU Re A NSE re cs eee R C
IE GBNES ED 5 DEAR ees tLe aR ESE ee ©
Dytiscidae
UITEES SSO 5 os tor ARE PAT ata eae R LP ere BG Bho ee R
SA ea eA APT ate h-Vewre Tals cnaye «ja salva Pde dneg oh. fen ass alae te Gay ste & 5 Le RURe Sklay he
Hydrophilidae
REL GOASES Dei ee ee a era tp hvek otek
WIG DUVENHUSISD ay Paitin donakeNl se ohne eS eee jaa ER
Locus vaca. SR Se a Me PS a ae eae eR ae 2 oat ee cr eee ea R
Chrysomelidae |
GREP eI EE hai aE sth oe oie me IE Lire et SMe aN atta mat ads ol R
EJateridae
WUD TGS SONS oa OE Nea i ae A aa a eae
Scarabaeidae |
Ataenius sp.. REY CAPER ed IE ea ee R R
Phyllophaga probably futilis. . 1M was oe ae eRe aad ae tie
Trichoptera
Hydroptilidae. . ?
Oecetis cinerascens s (Hagen). .
Oecetis inconspicua (Walker). sees ee: i Ge Teds kN pct ee A Ec
Oxyethira sp... BS TEA) si el et Sn ee ae I i ta ol ae x xX
Orthotrichia sp.. 1 ey stag tea ante Rot Sacre Nestea eats
Ree eee Oe th cue Gate
Diptera
SOR OMOINIG Aes licvare Sins. ahaa hus saccave osreb aut =
MME CI se. Sree he pe ay ote sn We Foe ns hehe oe
Culicidae
(CU RGIAGEREIS SD othe c haa SNe Ere Oo eT cer ae ata
Syrphidae
EPOSHES Soe non Ges Ae se CP
PER POMIVIdAc Ee Sones eset Ke, Shea
RELIG eee rt ne ye ee a ed tn eh
Pisces
Chaenobryttus gulosus (Cuvier)................
Lepomis m. macrochirus Rafinesque............ eee
WMigcroprerus salmotdes (Lacépéde)........... 6. |e ces. ct eae
Za KM
eke)
oN @el vel apse rele)
o)
a Gane ceca
x vole)
a0
Ane wz
>
y°)
> PK
Q0 AAA BZ
o)
>
Gk
(2
14 Ittinois NatuRAL History SurvEY BULLETIN
The reason for calculating the volume
of each kind of food by both average of
volume percentages and percentage of total
volume is that these two calculations give
very different expressions of volume. The
average of volume percentages is influenced
by frequency of occurrence of a kind of
food but not by the size of a stomach nor
its fullness; thus, it gives the stomach con-
tents of a small fish the same importance
as those of a large fish and favors small
food items that appear in a high percent-
age of stomachs. On the other hand, the
percentage of total volume anh nees the
importance of large food items and there-
fore the diet of large fish. Since the per-
centage of total volume of a food is not
affected by frequency of occurrence (the
percentage of stomachs in which the food
occurs), it does not reflect the food habits
of individuals of a population but rather
the foods consumed by the population as
a whole. A few large items might be
important as food to a few large fish but
of no value to the smaller members of
that population.
Although the above differences have
been discussed in other food studies (Ben-
nett, Thompson, & Parr 1940:18; Mar-
tin, Gensch, & Brown 1946; Beck
1952: 398; Reintjes & King 1953: 96), a
complete food analysis employing both
methods has not been published to illus-
trate erroneous conceptions inherent in
references to volume as a percentage with-
out defining its derivation or meaning.
Principal Foods in Two Habitats
Food items of many kinds were found
in the stomachs of warmouths collected
from Park Pond and Venard Lake, table 5.
Considerable differences exist in the taxo-
nomic levels to which the food items were
identified.* A similar situation is found
in most food studies of fish and generally
is due to difficulties in the exact identifica-
tion of fragmentary animal remains. In
*Identifications of selected pee were made by the
following persons: Dr. H. H. Ross (Trichoptera), Dr.
ee Sanderson (Coleoptera and miscellaneous groups), Dr.
J. Stannard, Jr. (Hydrachnellae), Mrs. Leonora K.
Gioyd (Odonata), Mr. Robert Snetsinger | (Araneae), Dr.
E. Moore (Hemiptera), and Dr. W, R. Richards
pity. all at the time of this study with the Illinois
Natural History Survey; Dr. D. Burks, with the
Division of Insect Identification of the nieces States De-
partment of Agriculture (Ephemeroptera); Mr. Glenn R.
Webb. Ohio, Illinois (Gastropoda); and Dr. H. H. Hobbs,
Jr., University of Virginia (Decapoda).
Vol. 27, Art. 1
groups such as Odonata, individuals of
which were found in large numbers in the
warmouth stomachs and which were rep-
resented by many species not distinguisha-
ble except by a specialist, only selected
collections were identified to species. These
identifications extended the number of spe-
cies found in warmouth stomachs but pro-
vided no information as to the relative
abundance of individual members of these
species.
In both frequency of occurrence and
volume, the foods of warmouths collected
from Park Pond differed from the foods of
warmouths collected from Venard Lake,
tables 6-11. The six foods that, on the
basis of their volume and the percentage of
stomachs in which they were found, were
judged to be most important for each of
the two areas are considered below. Less
important food groups that appeared to be
significant in the warmouth diet are men-
tioned as miscellaneous foods.
Park Pond.—Four of the food groups
listed among the six most important in
Park Pond were included among the six
most important in Venard Lake. These
were the Decapoda, Ephemeroptera, Zy-
goptera, and Anisoptera. Trichoptera and
Pisces, among the six most important in
Park Pond, were comparatively unimpor-
tant in Venard Lake.
Decapoda.—Crayfish, which ranked first
in bulk as a warmouth food at Park Pond,
made up 50 per cent of the total volume
consumed by warmouths collected from
this pond. Decapods were found in 19 per
cent of the stomachs; the average of their
volume percentages amounted to 14. Cray-
fish were important for a few warmouths
(generally the larger ones) but of rela-
tively little value to the others.
Ephemeroptera.—Forty-one per cent of
the warmouth stomachs from Park Pond
contained mayfly nymphs (no adult may-
flies were found). These nymphs com-
prised less than 1 per cent of the total vol-
ume, but the average of their volume per-
centages was 10. Nymphs of three genera
were identified: Caenis sp. was the only
mayfly abundant in the stomachs; Siphlo-
nurus sp. was uncommon and Hexagenia
limbata was rare.
Zygoptera.—Damselflies (mostly
nymphs) occurred in 34 per cent of the
stomachs of Park Pond warmouths. They
August, 1957
made up 2 per cent of the total volume;
the average of their volume percentages
was 16. Eight species (four genera) were
identified ; no tabulation was made of the
percentage comprised by each species.
Anisoptera.—Dragonflies were less im-
portant than damselflies in the stomachs
of Park Pond warmouths. Dragonfly
nymphs, found in 14 per cent of the stom-
achs, made up only 2 per cent of the total
volume of food ; 6 was the average of their
volume percentages. Nine genera of drag-
onflies were identified.
Trichoptera.—Caddisfly larvae occurred
in a high percentage (36 per cent) of the
Wwarmouth stomachs from Park Pond but
amounted to only 3 per cent of the total
volume; 13 was the average of their vol-
ume percentages. The specimens identified
belonged to the families Hydroptilidae and
Phyrganeidae.
Pisces.—Fishes ranked second to cray-
fish in total volume of food in the stomachs
of Park Pond warmouths. They made up
36 per cent of the total volume and oc-
curred in 18 per cent of the stomachs; 14
was the average of their volume percent-
ages. Small sunfishes were most common,
but single individuals of several species
other than sunfishes were included.
Miscellaneous—Among the food items
somewhat less important in the diet of
Park Pond warmouths than the six listed
above were the amphipods. These occurred
in 24 per cent of the stomachs from Park
Pond but were absent from the Venard
Lake collections. Diptera larvae or pupae
(mostly chironomids) were identified in
38 per cent of the stomachs of Park Pond
warmouths but comprised less than 1 per
cent of the total volume of food. Sixteen
per cent of the stomachs contained cladoc-
erans.
Venard Lake.—The most striking dif-
ference in diet between the warmouths of
the two water areas was in the number of
fish consumed. Fish were found in less
than 2 per cent of the warmouth stomachs
from Venard Lake in contrast to 18 per
cent of the stomachs from Park Pond.
Isopoda.—Eleven per cent of the total
volume of food in the stomachs of war-
mouths collected from Venard Lake con-
sisted of Asellus sp. (a form previously
considered 4. communis), which occurred
in 27 per cent of the stomachs examined.
LarimorE: Lire History oF THE WARMOUTH 15
Isopods were found in only about 1 per
cent of the warmouth stomachs collected
from Park Pond.
Decapoda.—Crayfish occurred in only
10 per cent of the warmouth stomachs col-
lected from Venard Lake and comprised
15 per cent of the total volume of food in
these stomachs. They ranked second in
percentage of total volume in Venard Lake
stomachs, but the percentage was low in
comparison to that in Park Pond stomachs
(50 per cent of total volume).
Ephemeroptera——Mayfly nymphs, like
crayfish, comprised 15 per cent of the total
volume of food in warmouth stomachs
from Venard Lake, but they could be con-
sidered more important as food because
they were found in a larger percentage (43
per cent) of the stomachs. An average of
10 nymphs per stomach was found in the
stomachs that contained mayflies. Caenis
sp. was the mayfly most often found in
warmouth stomachs from Venard Lake.
Siphlonurus sp. was found in a larger per-
centage of stomachs from Venard Lake
than from Park Pond.
Zygoptera—Damselfly nymphs ranked
fifth in frequency of occurrence (14 per
cent of the stomachs) and fifth in total
volume (7 per cent) of food in the war-
mouth stomachs from Venard Lake.
Anisoptera.— Dragonfly nymphs or
emerging adults comprised the greatest
volume of food (38 per cent of total vol-
ume) in the warmouth stomachs from
Venard Lake. They were found in 17 per
cent of the stomachs. Nine different spe-
cies of dragonflies were recognized.
Diptera.—Forty-four per cent of the
warmouth stomachs from Venard Lake
contained Diptera larvae or pupae. Dip-
terans comprised only 2 per cent of the
total volume; 12 was the average of their
volume percentages. Five families of Dip-
tera were represented.
Miscellaneous.—Caddisflies were found
in 21 per cent of the stomachs from Ven-
ard Lake, a smaller percentage than in the
stomachs from Park Pond. Cladocerans
occurred in 51 per cent of the stomachs
from Venard Lake, ostracods and cope-
pods in smaller percentages of the stom-
achs. Cestodes, annelids, and collembolans
were represented in the stomachs of war-
mouths from Venard Lake but not in the
stomachs of warmouths from Park Pond.
16 Ittino1is NATURAL History SuRvEY BULLETIN Vol. 27, Art. 1
Table 6.—Stomach contents of 64 warmouths collected
Sromacus From 38 Fisu or Less Tuan 5.0 INcHES
Average
Foop ITEM Percentage | Number of
of Stomachs | Organisms
Containing | in Stomachs
Organism | Containing
Them
Average of | Percentage
Volume of Total
Percentages Volume
RSARETOIMMIE SE ahs oie bt yt ks eth ns 8
U8 EATS Sie be ant MR aan ae ry teat! a
Coinenoda se ess. hele Sat ate Ph 3
Tee i pa age Me OM ERD eae rig gee 13
EASED «ERS RG Renae rare Pe oe ee s
SCN 82 ic sigs wiles Sosa ae he ite Ee 0
Iai GET Ina nie de Oar ea orcad He sinres RR BAE 5
Pilemerapeeta: a: U0 Sk eins Pe RU 32
Ppinearihel ie 3-6 gah roe ee ee 32
TRMETRIER ALD catenin iS k's vin eae eee 21
TREE FSS Seat So See Sai PS i AE OL 5
Piemimitetd: neste ee so Yin prea 3
Galssstrta trast hh 2S 3
Retentions As ates ae 16
| EE apa anette tba Rp pce Rte Mant oer 24
IS EER Soo ee Sato os oe Sean Ie 21
Hilamentousialpaess: tac sess nee ee ie ee 5
Pieheriplants ? ois. ab) eet ie et ae 5
Gen gnicdebrists 020i sepsis ies Cte toes 0
aN
eNore
. —
St DO tO OF
—
nn ind
Sor SonursSursssog oo
SCAPYUNODHOAWOHOHN’ AN
CUDHDOBPHEOREPOODUNHORW NW
Table 7—Stomach contents of 79 warmouths
Stromacus From 52 Fisy or Less Tuan 5.0 INcHEsS
Average
Baondlvru Percentage | Number of
of Stomachs | Organisms
Containing | in Stomachs
Organism | Containing
Them
Average of | Percentage
Volume of Total
Percentages Volume
EVOL Reem eat esa ae tote er 0
paneepeact ls My net ee le Ree 8
Rolie rae: intl eee ee eg ad 285
Ree S CE co ate ach i Nok es Bh ctu as 13
CSE COU A hse serine me caans, ah cha taal ooo -
AeA IIe eae PSOE oP uct Peck 37
spate eer seks Aaah (Nc Steinberg 2
RSP hs oie a ek Uh a ey ater oho ges 13
Momewmerapieta. 23...) a+ /o00} 5,44 bn ee es 56
2 TEE ah Se NORE ac A/S mane iret ea 52
PRE TT eet tage Sorbet SE OD 8
Pirie ty Ee nee pee Be ee 2
RintnenOptee as «5 atl. oats ee hs 0
Goteanier: agus: tec, het ees 0
RRRIOHAD Cra: 2. orcs ee ete > Be ces a tiers 40
Le eR Ee Tae, erie 25
Pane ee as. Sk oo Oe rs ee ea 2
Rilamentousaleae . 9) Pisses cae eee ek 6
Riboeiakiss . ): +. 4de com Fak abides 8
OP aHICHIE BIS, «2 Uc), ert ah ehtoae et whee 23
YQUnOO
HDReKeMnonooodefWTTE DANK OS
nN
— in ©
Ne
OK OK NnNODOONNOWONS
—
—
to
NooSanccouhunorgsosso
, mE NWOOEPENNEENNWRUHO
PPRNAPOOCHENONWHEN’
—
August, 1957
Percentage
of Stomachs
Containing
Organism
in)
Nore
FOCCMAHNNHWUHOOAO
Percentage
of Stomachs
Containing
Organism
Larimore: Lire History oF THE WARMOUTH 17
from Park Pond in December, 1948, and January, 1949.
Sromacus From 26 Fisu or 5.0 IncHEs or More Sromacus From A. 64 Fisu
ee : Average ;
umber o Percentage | Number o Per-
Organisms Average of | Percentage of Stomachs} Organisms average of centage
P Volume of Total napieed E Volume
in Stomachs Pp Vol Containing |in Stomachs Pp of Total
Containing EPeentages ace Organism | Containing |* “TSP @8€S) Volume
hem Them
0 0.0 0.0 5 2 0.4 0.1
1 (ee tr. 9 4 2K tr.
0 0.0 0.0 2 1 tr. tr.
0 0.0 0.0 8 2. 1.9 0.1
1 (iit 0.1 3 1 1a, 0.1
1 16.2 45.0 9 1 6.6 36.6
1 0.8 0.4 3 1 0.4 0.3
» 4.0 0.1 23 3 1G 0.4
1 15.0 Ons 28 » 18.8 13}
2) She fe DAD 16 1 12.6 545
0 0.0 0.0 3 i 1.8 fates
0) 0.0 0.0 2 1 0.1 Ons
0) 0.0 0.0 2 i. i125 0.9
1 0.1 0.4 11 1 4.8 0.7
1 3.9 Onl 20 1 31.5 0.1
1 46.8 Sled 33 1 28.3 52.9
0 0.0 0.0 3 On. 0.3
OLE iL} 0.3 9 0.8 0.3
8.5 0.1 6 3.4 0.1
collected from Park Pond in March—May, 1949.
Sromacus From 27 FisH or 5.0 IncHEs or More Sromacus From Aut 79 Fisu
Average ele ee :
Number of Percentage | Number o Per-
Organisms aes of | Percentage of Stomachs| Organisms Average of centage
: olume of Total es - Volume
in Stomachs Pp Vol Containing |in Stomachs Beeccny of Total
Containing EE CeMBARCS ie tals Organism | Containing |* “TSS"*8°S| Volume
Them Them
i Sei tr. 1 1 is tr.
1 B85 the 6 1 ets! 0.1
0 0.0 0.0 15 3 3.4 ine
0 0.0 0.0 9 3 De) fits
0) 0.0 0.0 3 2 0.3 tie
1 On2 (ae 25 2 Bete Onl
0) 0.0 0.0 1 1 ele tr.
1 43.1 60.9 29 1 ied Efoy, 2)
2 0.8 iL Al 40 2. 7.4 es
1 8.4 0.8 47 2 20.9 2.9
1 4.5 0.8 10 1 eel te
1 ths fiige 3 1 0.1 tr.
1 30 0.2 1 1 1.0 0.1
1 0.5 fitz 3 1 0.2 tr.
2 op 0.3 33 3 9.0 183
2 1.4 0.2 39 4 10.6 (Ory
1 11.6 29.7 6 1 Sy Il Do
0.6 Ont 5 0.6 Ont
6.0 Sail 23 2.8 4.7
9.4 0.9 24 9.5 1.8
18 ILLinois NATURAL History Survey BULLETIN Vol. 27, Art. 1
Table 8.—Stomach contents of 131 warmouths
Sromacus From 98 Fis or Less Tuan 5.0 INCHES
Pine ae
Percentage umber o
Fae of Stomachs | Organisms
Containing | in Stomachs
Organism | Containing
Them
KSamtraporia so: ite Site coe eis sme bade sy lade aa 14
Pianeta. sei ca lass SRS OE nes 24
ROIETHRIA AY (ts CRE Ss ys a prose OS Bee 10
WStraCOd dace een aks oe a eat mae 5
PAPA ET NLS i'd ais IS re, piece ST OR 35
CRP oe pion god sack wi we Oe ew Re 16
Araneae. Oe Sapa ean Hie tee Patenma tt Waites 1
Ephemeroptera. . SA, Tote EAE ot Nes 58
Zygoptera. . Boe ey Ne ics AG ils A ence ee 47
Bincgefeta ly eee we ees 17
| 3 FETE Ee Rh a a Oe ie nae OE, SRE Ctr 6
Blgmeutera cache val ec Oo oe eee eek 0
@olepnters latvse-i. ie: es hehe ne if
GCoaleopteta adults. p14 253 sue hose) oo aes 4
LSS oats ieee hia ead renee 52
Diptera. . RR AREY Forehand aus de eae ie 49
Pisces...... SAG Arran eet Rite Ma Lae pales sh 16
Banmeiousaloueee hss ok MS dete a 4
BTiS et HAINES ie re pitta ck sta gis eG ee a Po reals 11
Gieauic debis hea i ee 17
Average of | Percentage
Volume of Total
Percentages Volume
a _
OO
—
NEONwHNOT COUNhOSHG OOS
a
CURE UAD! BNE RAWH
Ww
Ses Sek
—
KBHNNAODWH’
nN
VON RP ORPEN BEEP ORUWD
_
Table 9.—Stomach contents of 117 warmouths collected from
Stromacus From 93 Fisu or Less Tuan 5.0 IncHEs
Average
Foop Item Percentage | Number of
of Stomachs | Organisms
Containing | in Stomachs
Organism | Containing
Them
Average of | Percentage
Volume of Total
Percentages Volume
CAS ELODOU EN Gis fou, vos cede sbouareni an Rae eS 11 2
GIAGOCEE AT ete eee Se pan lan teak 20 17
ORE DORA Aigo. = Sets tis peak Be ama oe 15
Meter ae ys, sUR Ee cack tes ee miele ere oe 3
MTPPOR Le rerio te ih gecs She os eee 35
aa Soc aaa 1
Decapoda. . PAGE UN cast Rke eae ashy cas +
Araneae. Seite ae one RPC Mae Bisa ver 1
Hydrochnellae. . Se edn cae a ee ae 1
Ephemeroptera. . FSS areaig Etats Lae ey 49
75 LARS ae eee a aides HCN 24
PURIAFECH ARS yi sols acute eee yeaa ae 15
isp | (i 21 Ree ea ce ae RESO Ale emenn of
Wolcapeera WIVAe ahs ei, Ales ae 1
olecptera Maiti. ogkek te oe ee eee 1
ee RU or ee 46
Diptera. . ene et Ue Horie ty SNe mhe ies 55
PIGGES oa. cs ROE ee eo ERT ee 11
Filamentous algae. . REESE Fa acta arte Mr 3
Higher plants. . eta Satan «Daehn te erie 8 8
Cereinae brs! ne eee 14
_—
oouneo ONDA WHHL
, SOW BNE NNE EE ENWOw
Les |
i)
pues NWNnWwWNat wooo” (> ens)
—t
— —
WBONSWOHEBUNDORPONH OR UN
>
oSo%NN
NDE ON’
August, 1957
collected from Park Pond in June-August, 1949.
Larimore: Lire History or THE WARMOUTH
Sromacus From 33 Fisu or 5.0 IncHEs or More
19
Sromacus From A ut 131 Fisu
peer : ‘ ee :
Percentage | Number o ercentage | Number o Per-
of Stomachs| Organisms Average of | Percentage of Stomachs} Organisms Average of centage
eel Volume of Total nein le Volume
Containing| in Stomachs Containing |in Stomachs of Total
0 : C .-. ~|Percentages| Volume Z - «| Percentages
rganism | Containing Organism | Containing Volume
Them Them
$ 1 tr. tr. 11 2 1.6 0.1
0 0 0.0 0.0 18 5 ee 0.1
0 0 0.0 0.0 8 5 12 tr.
0 0 0.0 0.0 4 4 (yi tr.
3 1 tr. (ae 27 3 2.4 0.3
55 1 49.4 733 26 1 20 64.3
3 1 fit. tr 2, 1 tr. the
30 1 0.5 0.1 51 3 8.8 1.0
15 1 5.8 0.3 39 2 16.0 2.8
9 1 6.3 Dell 15 1 5.4 3.2
3 1 0.2 tr 5 1 0.4 0.1
6 1 0.1 tr 2 1 tr. tr.
6 1 0.8 tr. 2 1 0.2 tie
6 1 Beli (0) 5 1 0.8 0.2
27 1 2.4 1.0 46 4 13} .55 4.1
6 4 1.0 fits 38 3 4.7 0.7
30 1 23.8 21.8 20 2 13.4 21.9
27 he? tr. 10 0.5 0.1
24 1.4 0.4 14 12) 0.5
2 De) 0.1 16 4.3 0.6
Park Pond in September—November, 1948, and September, 1949.
Sromacus From 24 FisH or 5.0 INcHEs or More Stromacus From Att 117 Fisu
ee : hes :
Percentage | Number o Percentage umber o Per-
of Stomachs} Organisms Average of | Percentage of Stomachs| Organisms Average of centage
paca |)s Volume of Total Siew Volume
Containing|in Stomachs Pp é Vol Containing |in Stomachs Pp of Total
Organism | Containing STEP REES oe Organism | Containing ercentages) Volume
Them Them
4 1 il tr. 9 2) DAV 0.1
0) 0 0.0 0.0 16 17 3.0 0.2
0 0 0.0 0.0 12 9 1.3 0.1
0 0) 0.0 0.0 3 3 0.1 tr.
8 2 0.4 tr. 30 2, 5.5 0.2
0 0 0.0 0.0 1 11 0.8 0.2
29 1 27.4 36.1 9 1 8.4 31.9
12 1 8.3 BRA: 3 1 2.4 3.6
0 0 0.0 0.0 1 1 0.1 (Be.
4 1 2.8 tr. 40 ey 10.8 0.5
12 1 6.4 th: 21 Q 10.0 1.0
8 2 0.4 0.5 14 1 5.8 hea
8 1 0.1 (or 9 D De) 0.6
0 0 0.0 0.0 1 1 0.1 fee
8 1 0.6 tr. 3 1 0.2 tr.
25 2 16.5 S92) 42 2 18.3 4.4
12 2. iil 0.1 46 3 Nop 0.6
83 1 26.4 55.6 15 1 11.8 53.8
0 0 0.0 0.0 3 0.4 tr.
21 5.4 0.5 10 1.8 0.6
12 S52) 0.5 14 5.6 0.5
20
Seasonal Trends
Each of the various seasons—winter,
spring, summer, and fall—designated in
the following discussion of seasonal trends
in warmouth foods and feeding encom-
passes 3 months. The seasons are biolog-
ical rather than astronomical; that is, they
are based on similarities in the foods pres-
ent and utilized by the fish. Winter in-
cludes December, January, and February;
spring includes March, April, and May;
summer includes June, July, and August;
fall includes September, October, and No-
vember.
The degree to which the stomachs from
individual warmouths of Park Pond and
Venard Lake were judged to be full was
found to be of little value as a measure
for determining seasonal trends in feeding
activities of the fish or relative amounts of
food consumed by them in various seasons
of the year. The stomachs from many fish
contained one and one-half to two times
ILLINOIS NATURAL History SURVEY BULLETIN
Vol. 27, Art. 1
as much food as apparently full stomachs
from fish of similar sizes.
A better measure of seasonal feeding
trends was found to be the average volume
of stomach contents of warmouths of sey-
eral size groups. This measure also proved
to have its limitations, most important of
which were concerned with differences in
rates of digestion and daily feeding periods
(discussed under “Daily Changes”) that
tended to mask the true seasonal trends.
Seasonal trends in average volume of
stomach contents (empty stomachs ex-
cluded) were apparent in three length
groups of warmouths taken from Park
Pond. In the warmouths of each of two
groups, 3.5—4.9 and 5.0-6.4 inches total
length, the average volume increased pro-
gressively in the three seasons following
winter; the average volume in the fall was
two to three times that in the winter. Ina
group of smaller warmouths (2.0—3.4
inches total length), the average volume of
stomach contents was greatest in summer;
Table 10.—Stomach contents of 71 warmouths collected in winter (December, 1948) and
81 warmouths collected in spring (March—May, 1949), all from Venard Lake.
Sromacus From 71 WarMmouTHS Stomacus From 81 WarmouTHS
CoLiecreD In WINTER COLLECTED IN SPRING
6 1 o NS ! vo
E|pSu | 5 E155 | 5
Foop ITEM yee Ge So ‘eg SE Soe = 52
v0 Plas to G os v0 fF 2s ‘3 O v5
oD an op on oD op op
ga°0 o&§ o § wc a4 O of § os a0
sa (PeO cg Se | Be | gah | PeO 6) See
i as HS & reas os & gS RPGs E ue Orn
BS-s |S Pec) £5 So | 58-5 [5 Pad) Fo oS
HAS |tOeh| ca Be | ans |leOeh| dm Oy
SY OZO a a tien sie rate 0 0 0.0 0.0 1 2 ti. ths
Amelia ssn seen Se see 0 0 0.0 0.0 1 1 0.4 0.4
Gastropoda. aces aa 3 1 0.7 0.2 0 0 0.0 0.0
Cladocera sar ec ee 96 18 28.9 13.4 56 11 9.6 0.8
Copepoda de tee 3 cts AAS if, 3.0 1.6 20 3 1.0 tr.
Ostracoday.ts aac cea 1 1 tr. tr. 0 0 0.0 0.0
Isopoda. . 45 5 27.8 48.5 Bi) 2. 29.1 13E9
Decapoda. . 0 0) 0.0 0.0 2 1 1.0 ss,
Hydrachnellae. . 0 0 0.0 0.0 1 1 tr. tr.
Collembola. . eae 0 0 0.0 0.0 1 1 tr. tr.
Ephemeroptera.. . eR Lo, 56 3 ah 2 12-1 60 24 20.8 20.4
EAGER. aes Ee Se: 4 1 pe: a9 a5 3 8.7 8.1
Anisoptera vena %ct sav ia 6 1 sy 15.8 36 3 23.4 47.8
Neuropteras. 3. 00.5.0. : 0 0 0.0 0.0 1 1 tr. tr.
Coleoptera larvae....... 0 0 0.0 0.0 7 1 0.2 0.1
Trichoptera. . 3 1 0.2 0.1 26 5 2ES 2A
Diptera. . ery: 48 2 DOS 4.4 38 i 1.4 os
Filamentous algae. neers 1 ngage tr. 0.1 2 fie 0.1
Higher plants. . eae 0 0 0.0 0.0 15 0.3 0.2
Organic debris.......... 1 tr. 0.1 23 Ld Tes
\ugust, 1957
Table 11.—Stomach contents of 107 warmouths collected
LarimoreE: Lire History oF THE WARMOUTH
21
in summer (June-August,
49) and 97 warmouths collected in autumn (October-November, 1948, and September, 1949),
ll from Venard Lake.
Stromacus From 107 WarmouTHs Sromacus From 97 WarMouTHS
CoLLECTED IN SUMMER CoLLecTED IN AUTUMN
oe y ae :
Els 5 bo 5 E 3 S 2p E
Ue eS: We) tee
Foop Irem ect es | eee eels Set Neca || eft eae
vV oo Za 8 ‘ @ vs oV Bo zak “ 0 vs
a2O GES e | go | #20 |DES es | 0
So o ons eal r) 9) »
Pee (S26 | 2 | £& | Eee lo2d_| $2 | 2
Goes lire: po eee ee od 6.8 (2a. 6 ose o oa
oS-s |S PSE) FS So | 59-5 |S Pee] & 5 re
AAs |tOsh| «a AH | ans |\tOek| tm Oa
BUS holies ee tac stor al aces 3 1 0.5 1.6 0 0 0.0 0.0
BSCEOPOGA, sic. 6s oe 5 2 Del hes 10 3 3.0 5.6
ReOCEEA ce oe cs tates 32 13 eS One 7 16 8.6 4.5
Mpepodae. sian: geet 11 3 0.8 (a Si 7 7.4 Ons
BRIA COC AEY ues casa) ots 16 5 2.4 (0) 31 24 10.0 ES
WPI GMAN tase Ne sictcien nue 8 2 Ig 6 0.4 3, 3 Sie Taal
CAD OG Alea: ced haikk es 24 1 18.0 35.0 8 1 6.8 44.9
phemeroptera......... 33 4 Ql 6.1 31 6 58, a3
WEOPLen AN. chsh. dei 9 1 5y(0) 3.6 10 3 4.5 4.7
RESO [IGEN oe easy vere 10 2 Vee 2550 16 Ds 10.1 22.8
Emap tena ie press seco 0 0 0.0 0.0 2 2 Ores 0.2
fymenoptera. 2... iy is: 0 0 0.0 0.0 1 1 ites tie
oleoptera larvae....... if D 0.8 1.4 2 2 0.2 0.1
oleoptera adults....... 1 1 tr. Ost 2 1 0.4 0.4
OTS eee 34 4 18.7 8.4 16 3 7.4 3.0
iptera.. 40 2 D5 1.2 49 Ti 18.5 4.2
isces. : 6 1 5.0 D5 0 0 0.0 0.0
ilamentous algae a eee 0 0 0.0 0.0 5 0.3 0.4
ligher plants. . Lane 9 ail 0.9 8 0.8 1.0
ganic debris.......... 10 Spall 1.6 20 10.7 2.9
he trend was downward through the sea-
ons to the lowest figure of the year in
pring.
Of some interest is the large number of
mpty stomachs taken in the winter from
he warmouths of Park Pond. Thirty-four
er cent of the warmouth stomachs col-
ected there in winter (44 per cent of the
tomachs collected in January) contained
0 food. These high percentages may re-
lect the influence of partial ice cover and
old water on the feeding activities of war-
nouths. A large percentage of stomachs
mpty at a time in which digestion was
low indicated that the fish were going
ong periods between feedings. A large
roportion of stomachs empty in summer
vas due to rapid digestion and reduced
eeding activity after midday.
Tables 6-11 show seasonal changes in
cinds of food eaten by warmouths in Park
Pond and Venard Lake, as indicated by
nalysis of stomach contents.
The following discussion and figs. 6 and
7 emphasize the highs and lows of the sea-
sonal trends in foods most commonly found
in the warmouth stomachs from the two
study areas.
Winter.—In the warmouth collections
from Park Pond, fish (Pisces) were found
in a larger percentage of stomachs in win-
ter than in any other season, fig. 6. Cray-
fish (Decapoda), which ranked second to
fish in percentage of total volume in win-
ter, were present in only 9 per cent of the
winter-collected stomachs examined (all of
them from large fish) and did not com-
prise so large a percentage of the total vol-
ume in winter as during the spring and
summer. Dipteran and caddisfly (Tri-
choptera) larvae, cladocerans, and amphi-
pods were found in a smaller percentage
of stomachs in winter than in any other
season of the year.
In the warmouth collections from Ven-
ard Lake in winter, the animal groups
Ittino1s NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 1
Table 12.—Stomach contents of 99 largemouth bass collected from Venard
Sromacus From 23 LarcemoutH Bass CoLLecTEeD
Durinc Marcu-May, 1949
Average
Foop Irem Percentage | Number of A ‘|p
of Stomachs | Organisms Volt of Total
Containing | in Stomachs Pp paces v Rae
Organism | Containing ne pd
Them
KCeStod ante. ce ee SSA ta ae ab ferab ache e eens 0 0 0.0 0.0
GEASEPGDOG Ay Yo MIA wade earn gi Benen sate ge 0 0 0.0 0.0
ltlipeeba ws cies Silos a eoarn ts ele Wis aN 22 70 5.0 1.9
REINA A S53 Vales oat ane ow eae din eas oeaete waren ate 0 0 0.0 0.0
Poa et ey a oe eee rege 39 4 pp ee US SS
Decapoda. . + 2 2.9 1.6
Araneae. 0 0 0.0 0.0
Hy -drachnellae. . 0 0 0.0 0.0
Ephemeroptera.. Losey Ra pea wires aE gOS 83 17 10.3 7.4
MyeGpteraa cs tot Ker ah Lacie sree aie ue ia 57 6 16.6 26.3
RBBB Pera, tg ak let sn ih ees oa ee epee 6h 3 36.9 37.8
Blcmapteras 2p. hare seus cop Mn pot ete 9 2 tr. tr.
remapicha eS sdije ) aik . Seis R ents layers uctN 0 0 0.0 0.0
Figen ptetas).t cose eta ys (xp rakes ees ah amet 0 0 0.0 0.0
Coleaptcra laude. 32...) Anes ee 0 0 0.0 0.0
Beers Ss gee epee 0 0 0.0 0.0
aes coe 0 0 0.0 0.0
Diptera. . 39 5 1.0 0.5
Pisces...... Bee Ae eMC Sac 0 0 0.0 0.0
Pilsmentons clea ne ee eee 0 0 0.0 0.0
Pheher plants. ge ac.) a ase ep eee 13 Ee cies 0.3 0.2
Geecnic duties... oat ee ees 26 5.0 11.0
found in the largest percentages of stom-
achs were cladocerans, mayfly nymphs, dip-
teran larvae, copepods, and isopods; each
of these groups was in winter at or near
its peak for the year in the percentage of
stomachs in which it was represented.
Fish and crayfish, which in winter led all
other food groups in percentage of Park
Pond stomachs in which they were found,
were not found in any of the Venard Lake
stomachs during the winter.
Spring.—In the warmouth collections
from both Park Pond and Venard Lake,
the nymphs of damselflies were found in a
larger percentage of stomachs, and com-
prised a somewhat larger percentage of
total volume of food, in spring than at
any other season. Mayfly nymphs were
present in a larger percentage of the stom-
achs from Venard Lake in spring than at
any other season; at this season, they were
present in a large proportion of the stom-
achs from Park Pond, also.
In the Park Pond collections, the per-
centage of stomachs containing fish and the
percentage containing dragonfly nymphs
were lower in spring than at any other sea-
son. The fragments of so-called higher
plants, mostly rootlets or parts of leaves,
that were found in 23 per cent of the
stomachs probably were taken accidentally
with other organisms. About two-thirds
of the stomachs that contained plant frag-
ments also contained crayfish.
In the Venard Lake collections, isopods
occurred in a larger percentage (57 per
cent) of stomachs in spring than at any
other season, fig. 7. They did not com-
prise so large a percentage of total volume
in spring as in winter, but their average of
volume percentages (29 per cent) was
greater and it was greater than that of
any other food item taken during the
spring. Dragonfly nymphs were present in
nearly half of the Venard Lake stomachs
collected in spring; the percentage of stom-
achs containing these nymphs, the average
of volume percentages, and percentage of
the total volume were much greater dur-
ing the spring than at any other season
Annelida, Collembola, Neuroptera, and
Bryozoa were represented as Venard Lake
August, 1957
Larimore: Lire History oF THE WARMOUTH
23
Lake during the period beginning October, 1948, and ending September, 1949.
Sromacus From 32 LarcemMoutH Bass
Cot.tecteD Durine June—Avcust, 1949
Sromacus From 44 LarGemMoutH Bass
CoLiecteD Durinc OcroBpeR—NovemBER, 1948,
AND SEPTEMBER, 1949
Average : wo ;
Percentage | Number o Percentage umber o Per-
of Stomachs| Organisms ae ee of Pee of Stomachs| Organisms eae of centage
Containing |in Stomachs reas = eau Containing |in Stomachs ee: of Total
Organism | Containing Percentages} Volume Organism | Containing Percentages Volume
Them Them
3 1 0.1 0.1 0 0 0.0 0.0
6 1 fils tte 7 1 0.1 tx:
3 199 3.0 0.4 59 178 23.0 10.1
0 0 0.0 0.0 7 2) tr. th:
0 0 0.0 0.0 9 2 0.4 0.1
34 1 18.5 19.8 9 1 9.0 54.0
3 1 tr. tile 2 1 tr. tr.
3 1 tr. tI. 0 0 0.0 0.0
47 8 2.4 0.9 77 26 24.1 8.7
47 4 17.6 6.3 30 3 5.8 Del
41 3 15.9 10.6 34 2 Sia 9.8
16 1 fies fit: pi] 1 6.0 0.8
3 1 tr. tr. 0 0 0.0 0.0
25 1 38) 0.7 2 1 tk. tr.
19 43 4.1 1.9 0 0 0.0 0.0
9 1 fits tii: 0) 0 0.0 0.0
6 1 0.2 tr. 14 1 gi 0.3
28 2 1.0 0.1 Sy 13 6.8 1.4
38 2 30.4 59.1 5 2 4.5 11.4
0 0 0.0 0.0 2, 0.2 0.1
6 Re 0.1 files 20 0.3 0.4
12 353 0.1 14 2.0 0.7
warmouth foods in spring but at no other
time.
Summer.—As new broods of young fish
became available in summer, a marked in-
crease in the percentage of warmouth stom-
achs that contained fish was noted in the
collections from both Park Pond and Ven-
ard Lake.
In the warmouth collections from Park
Pond, crayfish occurred in a slightly
smaller percentage of stomachs in summer
than during the spring but attained a peak
in the percentage of total volume of food
—64.3 per cent, fig. 6. The percentage of
stomachs containing mayfly nymphs and
caddisfly larvae increased progressively
from winter to summer; these groups were
found in proportionately more warmouth
stomachs taken during the summer than
at any other time of year in Park Pond.
_ The percentage of stomachs in which dam-
selfly nymphs were found was smaller in
summer than in spring.
In the warmouth collections from Ven-
ard Lake, caddisfly larvae were present in
a larger percentage of stomachs in summer
than at any other season. Caddisfly larvae
comprised only a relatively small part of
the total volume of food, but the average
of volume percentages was greater for cad-
disflies than for any other food utilized in
summer. Crayfish also were found in a
large percentage of the stomachs collected
in summer. Although crayfish made up a
smaller percentage of the total volume of
food in summer than during the fall
months, the percentage of stomachs con-
taining crayfish was three times as great
in the summer as in the fall. Fish were
found in the stomachs of only those war-
mouths collected in summer. Mayfly, dam-
selfly, and dragonfly nymphs comprised
smaller percentages of the total volume of
food and were present in smaller percent-
ages of stomachs in summer than in spring.
Fall.—In the warmouth collections
from Park Pond, fish comprised a larger
percentage of the total volume of food,
and crayfish a smaller percentage of the
total volume of food, in fall than in sum-
mer; the percentages in the fall were
nearly equivalent to those observed during
24 ILLtinors NATURAL History SurvEY BULLETIN Vol. 27, Art. 1
FREQUENCY OF PER CENT OF
OCCURRENCE PER CENT TOTAL VOLUME
CADDISFLIES @
rad
DRAGONFLIES S
<
ig
DIPTERA g
WINTER
|
° 10 20 30 40
PER CENT
SPRING
10) 10 20 30 40 4
PER CENT
-
|
60
FALL
10) 10 20 30 40 50
PER CENT
Fig. 6.—For each of the most important foods taken from the stomachs of warmouths col-
lected from Park Pond in each of the four seasons of 1948 and 1949, the percentages of stomachs
containing these foods (frequency of occurrence) and the percentage of the total volume of
food represented by each of these important foods.
August, 1957 Larimore: Lire History oF THE WARMOUTH 25
FREQUENCY OF PER CENT OF
OCCURRENCE PER CENT TOTAL VOLUME
DRAGONFLIES
\SOPODS
0) 10 20 30 40
PER CENT
SPRING
) 10 20 30 40 50 60
PER CENT
2)
ww
re
=
jo)
oO
e
SUMMER 9
0 10 20 30 40
PER CENT
FALL
PER CENT
Fig. 7.—For each of the most important foods taken from the stomachs of warmouths col-
lected from Venard Lake in each of the four seasons of 1948 and 1949, the percentage of stom-
achs containing these foods (frequency of occurrence) and the percentage of the total volume ot
food represented by each of these important foods.
26 Ittinois NAtuRAL History SuRvEY BULLETIN
the winter months, fig. 6. Although fish
comprised more than one-half the bulk of
food in winter, they were taken from only
15 per cent of the stomachs collected in
the autumn. Dipteran larvae (largely chi-
ronomids) comprised less than 1 per cent
of the total volume of food each season but
occurred in a large percentage (33 per
cent or more) of stomachs each season—
the largest percentage in the fall. In the
fall collections, dipteran larvae were pres-
ent in 46 per cent of the stomachs; the ay-
erage of volume percentages for these lar-
vae was 9.2. Caddisfly larvae were pres-
ent in a large proportion of stomachs and
ranked first among all food groups in av-
erage of volume percentages. Mayfly and
damselfly nymphs were found in a smaller
proportion of stomachs collected during
the fall than during the summer, whereas
dragonfly nymphs were present in about
the same percentages of stomachs in these
two seasons.
In the warmouth collections from Ven-
ard Lake, mayfly and damselfly nymphs
were present in about the same percentages
of stomachs during the summer as during
the fall. In November, nymphs of the
mayfly, Siphlonurus sp., showed a sudden
pulse of occurrence that extended into De-
cember. Caddisfly larvae were present in a
smaller percentage of stomachs collected in
fall than in the summer months. Through-
out the four seasons, dipteran larvae were
found in consistently high percentages of
stomachs—38 to 49 per cent—the highest
percentages in the fall and winter, fig. 7.
Chaoborus sp., a dipteran larva, was found
only occasionally during the spring and
summer; but, during the fall months and
in December, it was found in large num-
bers of stomachs. Gastropods (snails) and
ostracods were found in higher percentages
of Venard Lake warmouth stomachs in the
fall than at other seasons.
Daily Changes
During the summer, when water tem-
peratures were high, digestion in the stom-
achs of fish was rapid, and food remained
in these stomachs for only a few hours. At
this season, it was possible to determine
daily feeding periods of warmouths at Park
Pond by comparing the percentages of
empty stomachs taken in morning col-
Vol. 27, Art. 1
lections with those taken in afternoon col-
lections, table 13. The influence of indi-
vidual fish size, and of size groups repre-
sented by few individuals, was reduced by
eliminating from the calculations all war-
mouths less than 2.0 inches or more than
6.4 inches total length.
Only 4 per cent of the warmouth stom-
achs collected in the morning were empty,
whereas 50 per cent of those collected in
the afternoon contained no food.
On July 8 and August 1, 1949, collec-
tions were taken soon after sunrise and as
late in the evening of the two days as fish
could be taken with the shocking apparatus
without the use of artificial lights. The
daily feeding pattern was quite evident in
these collections, table 13. Stomachs re-
moved from fish collected between 6:00
and 7:15 A.M. on July 8 were “relatively
full of very dark material”; in contrast,
the stomachs collected between 6:15 and
7:45 p.m. “seemed rather empty, the up-
per intestine completely empty, with only
the last three-fourths inch of the lower in-
testine containing heavy black material
representing the early morning feeding.”
In stomachs of fish of selected size
groups (excluding fish with empty stom-
achs), total volumes of the food masses
averaged consistently lower (by 24 per
cent or more) for individuals taken in the
afternoon than for those taken in the
morning.
Monthly collections of stomachs from
Venard Lake in the warm period of the
year (1949) indicated for the warmouths
of this body of water a daily feeding pat-
tern somewhat similar to that of the war-
mouths of Park Pond. Of four collec-
tions from Venard Lake in the warm
months, when the daily feeding pattern
might be evident, two were taken in the
morning and two in the evening; 13 per
cent of the stomachs in the two morning
collections and 26 per cent of the stom-
achs in the two afternoon collections were
empty. The differences between morning
and afternoon collections were less evi-
dent at Venard than at Park Pond, prob-
ably because the collections were taken
from Venard late in the morning and
early in the afternoon.
There was evidence of some feeding ac-
tivity by warmouths in late afternoon.
Although most of the food materials found
August, 1957
Larimore: Lire History oF THE WARMOUTH
Zh
Table 13.—Number of warmouths in morning and afternoon collections from Park Pond,
June 2-September 2, 1949, and number of those warmouths with empty stomachs. Figures in-
clude only those for fish between 2.0 and 6.4 inches total length.
MornincG AFTERNOON
Co.tiection Date
Number of Number of Number of Number of
Fish Empty Stomachs Fish Empty Stomachs
June 2 Moave 3 resin 5 1
June 10 25 3 Seen eee eel ee ete ren eel or
July 5 soy ead Sigarees 23 8
July 8 25 0 18 11
EMIGMSCS eS Sin ea 19 1 16 11
PATIOS tab chy sgh, hi edoras cis 16 1 wha ae t Nicaea
September.2............. 28 0 we PERE
Total number of fish....... 113 5 62 31
Per cent of stomachs empty].......... 4 um 50
in stomachs collected in the afternoon dur-
ing the summer were well digested, a few
were fresh items; most of the materials
were nearly digested or else quite fresh, a
situation that suggested a resumption of
feeding after a period of no feeding. After-
noon feeding during the summer was either
very light or it occurred very late in the
day, possibly just at dusk when it became
too dark for fish to be collected without
lights.
Influence of Fish Size
The yolk supply of warmouth larvae
observed under laboratory conditions usu-
ally was exhausted within 4 days from
hatching; without food, the larvae starved
to death in 10 or 11 days at 24-25 degrees
C. Ordinarily, the postlarvae began feed-
ing at least by the seventh day of life.
Stomachs of warmouth larvae collected
from outdoor tanks contained a few flagel-
lates and ciliates and many bacteria. One
or two of the large protozoans made a
rather big meal for an 8-mm. larva. When
14 days old, the warmouth larvae ate con-
siderably larger organisms, feeding even on
small mosquito larvae. Both in natural
waters and in the laboratory, warmouths
19 mm. long were observed feeding vora-
ciously on postlarval warmouths 5 mm.
long.
In a study of differences in food taken
by larger fish, the stomach contents of war-
mouths from Park Pond and Venard Lake
were grouped according to sizes of fish
from which the stomachs had been taken.
Since it was necessary to present these
analyses in compact tables, fish from
Park Pond were grouped in two length
ranges, tables 6—9, and fish of all lengths
from Venard Lake were grouped to-
gether, tables 10 and 11. Some of the rela-
tionships between lengths of fish and foods
taken, such relationships as are obscured
in the tables by combining data for fish of
various lengths, are given in the following
general statements.
Cladocerans, copepods, and_ ostracods
were taken mostly by warmouths less than
3.5 inches in length and were the principal
foods of warmouths less than 1.7 inches in
length, which only occasionally took small
mayfly nymphs or dipteran larvae. Amphi-
pods were an important food for small
warmouths at Park Pond but were utilized
by very few fish larger than 4.9 inches in
length. Snails were eaten mostly by war-
mouths between 2.5 and 4.9 inches in
length.
Crayfish were eaten by more large war-
mouths than small ones at Park Pond. In
contrast, crayfish were eaten by more small
warmouths than large ones at Venard
Lake, presumably because large numbers
of small crayfish were available to the fish
there during the summer months.
In both study areas, mayfly nymphs were
taken by a larger percentage of small war-
mouths than of large ones; however, at
Park Pond in summer they were taken by
30 per cent of the warmouths over 5.0
inches long. At Venard Lake, where both
Caenis and Siphlonurus occurred in large
numbers, the nymphs of Caenis were taken
28 Ittinors NaturAL History SurRvEY BULLETIN
mostly by warmouths between 2.0 and 3.4
inches, whereas the nymphs of Siphlonurus,
which were larger, were eaten generally
by larger fish, up to 5.2 inches in length.
Caddisfly larvae were eaten by a larger
percentage of small warmouths than of
large ones; the seasonal trend in consump-
tion was somewhat similiar for fish of all
sizes. Damselfly and dragonfly nymphs
were utilized as food by warmouths of all
sizes except those less than 2.0 inches long.
Fish were eaten by a greater percentage
of large warmouths (over 5.0 inches in
length) than of small ones.
The average volume of food found in
the stomachs of warmouths of various sizes
was not directly proportional to the length
or weight of the fish; the larger the war-
mouth the greater was the volume of food
taken in proportion to its size. The stom-
achs of very small warmouths occasionally
contained relatively great amounts of food,
but small warmouths feeding on many
small items seldom experienced the ex-
treme distention of the stomachs that oc-
curred in many large warmouths when
feeding on comparatively large fish or
crayfish.
The percentage of stomachs that were
empty was smaller among small war-
mouths than among large ones. The per-
centages of Park Pond warmouths with
empty stomachs were as follows: fish of 1.9
inches or less total length, 3 per cent; fish
of 2.0—-3.4 inches, 18 per cent; fish of
3.5-4.9 inches, 24 per cent; fish of 5.0-6.4
inches, 32 per cent; and fish of 6.5 inches
or larger, 28 per cent. Small warmouths
feeding on many small items apparently
had a more certain food supply than had
large warmouths, which had relatively
fewer large organisms on which to feed.
Interspecific Competition
Largemouth bass stomachs were col-
lected from Venard Lake at the same time
the warmouth stomachs were obtained. Be-
cause only four largemouths were taken
during the winter, their food habits for
this season were omitted from consider-
ation here. The majority of the bass taken
(92 per cent) were between 5.5 and 9.0
inches total length. Of 107 bass stomachs
collected, 99 contained food materials,
table 12.
Cladocerans were found in surprisingly ©
large numbers in the stomachs of large-
mouths up to 7.5 inches in length—791 of
them in the stomach of one 6.4-inch bass. ©
Of the largemouth stomachs collected in
the fall months, cladocerans (almost ex-
clusively Simocephalus sp.) were found in
59 per cent. Very few were found in the
bass stomachs collected in summer. Cladoc- —
erans were found in relatively high per-
centages of the warmouth stomachs col- |
lected from Venard Lake throughout the ~
year; they did not show an increase in
utilization by warmouths during the fall
months comparable to the increase in uti-
lization by largemouth bass. Cladocerans
were found in 32 and 37 per cent of the
warmouth stomachs collected, respectively,
in the summer and fall and in 96 per cent
of the warmouth stomachs collected in De-
cember. Copepods were found in very few
stomachs of the largemouth bass, and
ostracods were found in none. Isopods
were found in greater percentages of both
largemouth and warmouth stomachs col-
lected in spring than at any other season.
Fish and crayfish together comprised 64
per cent (36 and 28 per cent, respective-
ly) of the total volume of largemouth bass
food. The percentages of bass stomachs
containing fish or crayfish were low in the
spring, high during the summer, and low
again in the fall. The seasonal trend was
somewhat similar to that for warmouths at
Venard Lake. Bass stomachs collected in
August contained very few items except
fish and crayfish.
That mayfly nymphs and midge (Dip-
tera) larvae were important bass foods at
Venard Lake was shown by the consist-
ently large percentage of stomachs in which
they occurred. Percentages were larger in
spring and fall than in summer. Mayfly
nymphs were found in at least as large a
percentage of bass stomachs each season
as was any other kind of food organism;
they were found in a larger percentage of
bass than of warmouth stomachs. The fall
increase in utilization of mayfly nymphs
by bass was not followed by a similar in-
crease by warmouths. Nymphs of Siphlo-
nurus sp. accounted for the fall increase
in consumption of mayfly nymphs by bass;
as many as 125 were found in each of sev-
eral bass stomachs taken during Novem-
ber. Only in the spring collections did the
Vol: 27, Art. 1
August, 1957
nymphs of Caenis sp. occur in bass stom-
achs as frequently as those of Siphlonurus ;
Caenis was consistently the species of may-
fly most abundantly taken by warmouths.
The variation in utilization of these may-
flies may have come from differences in
their habitats: Siphlonurus is generally
concentrated in deeper water than is
Caenis and would be available to large-
mouths feeding in open areas of the lake.
Caenis is a shallow-water mayfly and
would be taken by warmouths feeding
along the banks and in shallow weed beds.
The percentage of bass stomachs that
contained damselflies (Zygoptera) and/or
dragonflies (Anisoptera) decreased from
spring to fall. A smaller percentage of
warmouth than of largemouth stomachs
contained nymphs of the Odonata. Large-
mouth bass stomachs contained more
adults and subimagoes of damselflies than
did warmouth stomachs; in the June col-
lection of bass stomachs, these forms out-
numbered the nymphs taken.
Larval and adult beetles (Coleoptera),
bugs (Hemiptera), and bees and ants
(Hymenoptera) occurred at peak abun-
dance in bass stomachs during the summer,
especially in June. The incidence of these
insects was much greater in largemouth
bass than in warmouths at Venard Lake.
Larvae of the aquatic beetle Peltodytes
Larimore: Lire History oF THE WARMOUTH 29
sp. were eaten in large numbers by a few
largemouths; in June, 131 of the larvae
were found in the stomach of one individ-
ual and 115 in the stomach of another.
Certainly the foods and feeding areas
of warmouths and largemouth bass over-
lapped in Venard Lake. However, even
though largemouth bass and warmouths
fed on the same kinds of organisms, and
even though several of these organisms fol-
lowed similar seasonal patterns of occur-
rence in the stomachs of the two fishes, the
competition was somewhat reduced by dif-
ferences in feeding habits. Warmouths
tended to consume the organisms on the
soft bottoms, in shallow waters, and along
the banks; largemouths fed more on the
surface organisms and_ free-swimming
forms in deeper or more open parts of the
lake.
General Conclusions on Food Habits
Considerable differences have been ob-
served in the contents of the stomachs of
warmouths taken in small numbers at dif-
ferent seasons or from widely separated
localities, table 14.
Forbes (1903:48-9) analyzed the stom-
ach contents of warmouths collected at
scattered localities in Illinois and neigh-
boring states and considered the foods uti-
Table 14.—Average of volume percentages for the food of warmouths studied by Forbes
(1903), McCormick (1940), and Rice (1941) and for the food of warmouths of approximately
the same sizes, and collected at about the same times of year, from Park Pond and Venard
Lake.
Forses (1903)|McCormick (1940)|Rice (1941) PresENT Stupy |PResENnT Stupy
ILLINOIS Ree.troot Lake /ReEeLFroot LAKE|Park Ponp |VENARD LAKE
AUTUMN SUMMER SUMMER SUMMER SUMMER
Foop Item |6 FisH 69 Fisu 45 Fisu 59 Fisu \27 Fisu
LencrTH, LenetH, IncHEs* |Leneru, INcHEs*|LeENcTH, IncHEs Lencru, INCHES
INCHES 3.3-8.7 3.3-6.5 3.4-6.4 3.4-6.4
3+ (5.4 AVERAGE) (4.8 AVERAGE) |(4.7 AVERAGE) |(4.3 AVERAGE)
(raydish: 6s... OR ett Re 46.38 99.5 29) 7 Dig he Th
Entomosttaca.|........+-< 2.90 tr. 0.7 Os
Mayflies...... 25 2.90 (age 2.9 Ey)
Mamselfises S.J )e pfs ae ee 1.59 Weed 3.8
MAP ONtlieS ei-\\scss aes ase ms 10.87 52 23.8
Hemiptera. ... 18 7.68 Bot Br 0.3 ee oe
Wiptera’ larvae!) sso: -. 6. 10.03 tr. 4.6 | 3.9
Miscellaneous |
insects..... 10 5.07 eo V7i-3
(PS) he ere eae 47 7.94 20.5 5.9
Miscellaneous
REUSE Csi Mae ices ote tt a a 4.64 tr. Bee 11-2
*Measurements here are equivalents of metric measurements given by author.
30 Ittinois NaturAL History SurvEY BULLETIN
lized by fish of different sizes. The small
warmouths in his study had eaten large
numbers of Entomostraca, as had the small
warmouths at Venard Lake and at Park
Pond. In his six adult warmouths, table
14, crayfish were not represented, and fish
made up a larger percentage of the food
(47 per cent) than has been reported in
other studies. Forbes related the espe-
cially piscivorous habit of this species to the
large size of its mouth. Dragonflies were
noticeably absent in all the warmouth
stomachs he examined.
Data in studies made by McCormick
(1940:73) and Rice (1941:26) at Reel-
foot Lake, Tennessee, table 14, empha-
sized the differences in foods utilized by a
species in successive years, even at the
same location and during the same season
of the year. McCormick examined 69
warmouth stomachs which contained food
and found that the average of volume per-
centages of insects was 38.14 per cent. The
comparable figure at Park Pond was 40.9
per cent. Crayfish were higher and fish
were lower in the average of volume per-
centages of warmouth food at Reelfoot
Lake than at Park Pond. A year after Mc-
Cormick’s study, Rice examined another
series of warmouth stomachs from Reelfoot
Lake. Of 45 stomachs which contained
food, only 1 had food other than crayfish,
table 14.
For the periods of time covered by the
studies cited in table 14, warmouths at
both Venard Lake and Park Pond utilized
a greater variety of food items than did
warmouths in the other places listed, as is
indicated by the percentages of “miscella-
neous insects” and ‘“‘miscellaneous items.”
Lewis & English (1949:321) examined
the stomachs of 29 warmouths from Red
Haw Hill Lake, Iowa. The fish were
collected from April through July and
ranged from 40 to 177 mm. in total length.
In the 17 stomachs that contained food,
“food items occurred as follows: 2- to
4-inch fish, 7; crayfish, 4; vegetable de-
bris, 2; unidentified insect larvae, 4; leech,
1; dragon-fly naiad, 1; unidentified in-
sects, 2; and snails, 1.” These figures
probably refer to the number of stomachs
in which each kind of food was found and
not to the numbers of individual food
items. The conclusion from this study was
that ‘On a volumetric basis, fish and cray-
Vol. 27, 7Art: 1
fish were the most important food items.”
In a rather general statement involving
five fishes, Black (1945: 463) mentioned
that the warmouth in Shiner Lake, Indi-
ana, hunts the northern mimic shiner, No-
tropis volucellus volucellus (Cope), to
the exclusion of almost all other food. At
Park Pond, where many species of min-
nows were present, small sunfish were
more commonly taken by warmouths than
were minnows.
Hunt (1953:29) examined 25 small
warmouths from the Tamiami Canal west
of Miami, Florida. Twelve of these fish,
ranging from 1.4 to 3.5 inches in total
length, contained food material composed
exclusively of animals, including the fol-
lowing organisms: dragonfly, damselfly,
and mayfly nymphs; dipteran larvae of va-
rious kinds; a few scuds and large ostra-
cods; and a large number of small shrimps,
Palaemonetes paludosa.
Huish (1947:15-6) examined 17 war-
mouths from Lake Glendale (southern
Illinois) during the summer of 1946.
These fish, caught on artificial flies, ranged
from 5.0 to 7.5 inches in total length.
Of the 14 fish whose stomachs contained
food, there were 3 with small fish, 1 with
a tadpole, 3 with dragonfly nymphs, and 7
with crayfish.
Fish, crayfish, and immature forms of
aquatic insects comprised the important
foods for most of the warmouths involved
in the present study. Diets of the war-
mouths in Park Pond were found to differ
from the diets of the warmouths in Ven-
ard Lake both as to the kinds and to the
amounts of certain organisms eaten in va-
rious seasons and by fish of different sizes.
This study and others, some of which have
been cited above, make it seem very un-
likely that there is any specific diet or
highly restricted food preference for this
species. Food items of many kinds are ac-
ceptable to the warmouth; this fish may
feed upon any of those items that are read-
ily available.
REPRODUCTION
Whether a fish population overcrowds
its habitat is determined in part by its rate
of reproduction—the development of sex
products and the subsequent growth and
survival of young fish.
August, 1957
Development of Sex Products
In interpreting the stages of develop-
ment of sex products in a fish such as the
warmouth, which spawns over a period of
several months, one must keep in mind
that all of the germ cells do not go through
the cycle of maturation simultaneously ;
instead, small groups of these cells mature
at intervals and are spawned. This proc-
ess is accompanied by a continuous recruit-
ment of additional cells from the primor-
dial stock. Thus, in a gonad in spawning
condition, in addition to the fully matured
sex products, there are other groups of
cells representing earlier stages in the
maturation process.
Larimore: Lire History oF THE WARMOUTH
31
Annual Sexual Cycle.—Terms de-
scriptive of the appearance of the fish gonad
are useful for designating stages of devel-
opment associated with seasons, table 15.
Some of the terms used here are the same
as those used by Bennett, Thompson, &
Parr (1940:17).
Partly because the gradual process of
growth of germ cells varies among indi-
viduals and partly because the develop-
mental process is influenced by climatolog-
ical conditions, the periods during which
the various designated stages may be found
overlap and are not exactly the same from
year to year for either individual fish or
for populations. Overlapping of develop-
mental stages was evident in warmouths
Table 15.—Appearance and significance of each stage in the development of warmouth
gonads, related here to the seasonal occurrence of each stage in warmouths from Park Pond,
1948 and 1949.
STAGE OF APPEARANCE OF GONADS SIGNIFICANCE OF STAGE SEASON
DEVELOPMENT IN DEVELOPMENTAL OF
or Gonaps Male Female Process STAGE
Latent Clear pinkish white|Light amber, often _|A quiescent period; gonad|All year for fish
to colorless; a with small red dots; |containing only primor- junder 3.5 inches;
narrow translucent |lobelike in form dial germ cells July 1-April 15
strand and somewhat trans- for fish over 3.5
lucent inches
Poorly Pinkish white, Pinkish orange to Initial maturation March 1—May 1
developed |opaque, becoming _ [light yellow; of sex products
ribbon-like slightly granular
and somewhat
enlarged
Well White, opaque; Bright yellow; Advanced development |April 15—June 1
developed |ribbon-like, with very granular and of germ cells; heavy
wavy margins fully distended, yolk accumulation in
with opaque eggs ova
Spawning Appears as in Appears as in Completed germ cells May 15—August
condition jpreceding stage but |preceding stage but _|free in gonad, ready 15
flowing milt when |flowing eggs when to be discharged
gently pressed gently pressed
Partly White to gray; more} Yellow to orange, No germ cells free in June 1—August 20
spent nearly flat than in |/with congested gonad, but a considerable
spawning condition |blood vessels; stock of well-developed
less distended than ova and sperm remain-
in spawning condition |ing
Spent Muddy white, Reddish-orange, Remaining matured June 15—Septem-
becoming smaller
and less distended
flaccid, with
congested blood
vessels
germ cells resorbed; ber 1
gonad reorganizing, but
effect of spawning still
evident
32
collected from Park Pond during the
spawning season of 1949. These fish were
divided into two size groups established
on the basis of differences in maturation:
in the first group were “large” warmouths,
those of more than 5.4 inches total
length; in the second group were “small”
warmouths, those between 3.5 and 5.4
MAY JUNE JULY
100
80
60
40
PER CENT
20
IN.
MALES 3.5-5.4
MAY
JUNE
JULY
PER CENT
FEMALES 3.5-54 IN.
| LATENT
[__] spawninG CONDITION
Intrnors NATURAL History SurvEY BULLETIN
100
Vol. 27, Art. 1
2. All the “large” individuals took part
in spawning activities, whereas a consid-
erable proportion of the specimens be-
tween 3.5 and 5.4 inches remained imma-
ture during the entire nesting season.
3. The ‘‘small” warmouths recovered
more quickly from the effects of spawning
than did the “large” ones; all of the
MAY
JUNE
JULY
80
60
40
20
IN.
MAY JUNE JULY
QV?
o,
o,
: S32
IN.
POORLY TO WELL DEVELOPED
EY PARTLY SPENT SPENT
Fig. 8.—Percentage of warmouth males and females (two size groups) in each of five stages
of sexual development during May, June, and July. These warmouths were collected from
Park Pond, May 13 to August 1, 1949.
inches total length. Warmouths shorter
than 3.5 inches were eliminated from this
part of the study because they would not
mature in the then current season. The
following generalizations may be made re-
garding the season of greatest sexual ac-
tivity of the warmouth, fig. 8:
1. The “large’’ warmouths (over 5.4
inches total length) attained spawning
condition sooner and spawned over a longer
period than did the “small” fish (3.5-5.4
inches total length).
“small”? warmouths were in a latent condi-
tion by August 1, whereas among the
larger fish only 14 per cent of the males
and 33 per cent of the females possessed
gonads that had become reorganized by
that date.
4. The males ripened slightly earlier in
the season than did the females and re-
mained sexually active somewhat longer.
In the smaller size group (3.5—5.4
inches total length), a considerable propor-
tion of both males and females had latent
:
:
August, 1957
gonads after the first week in May, fig. 8.
The continuous rise in percentage of latent
gonads found in this size group during the
nesting season may have resulted from (1)
rapid reorganization of the gonads of early
spawners, (2) failure of some small indi-
viduals to spawn and prompt return of
these individuals to the latent condition,
(3) growth of fish during May, June, and
July, which resulted in the recruitment of
some sexually undeveloped fish into the
3.5—5.4-inch group and the loss of some
sexually mature fish from this group to the
size group beyond 5.4 inches, and/or (4)
inadequacy of collections and their failure
to represent true proportions of individuals
in the various developmental stages.
Field observations showed that sexually
mature females do not have free ova
(which can be forced out by gentle pres-
sure on their sides) except immediately
before and during the spawning act,
whereas sexually mature males may be in-
duced to extrude milt during much of the
spawning season. These observations may
explain the fact that many more males
than females were classed as ripe. “The
scarcity of small males that were classed
as completely spent was due probably to
the dithculty of separating partly spent
from completely spent individuals in the
small sizes.
By expressing the weight of gonads at
regular intervals through the year as per
cent of body weight, one can follow the
increase and diminution in size of the sex
glands and fit the observed spawning con-
dition of fish into the annual sexual cycle
(James 1946 and others). Statistics on
monthly gonad weight—body weight rela-
tionships for warmouths in Illinois were
based on 222 females and 260 males col-
lected in Park Pond from early October,
1948, to early September, 1949, fig. 9.
The fish were divided into three size
groups: (1) less than 3.5 inches total
length, (2) 3.5—5.4 inches total length,
(3) more than 5.4 inches total length.
Most of the warmouths of 3.5 inches and
longer total length were sexually mature;
most below this length were sexually im-
mature.
During the period beginning with Sep-
tember and ending with March, there was
no appreciable change in gonad weights
among warmouths. Soon after the initial
LarImorE: Lire History oF THE WARMOUTH 33
rise ‘of water temperatures in March, the
gonads in warmouths longer than 3.5
inches began to enlarge, and they increased
rapidly in weight during April and May.
The ratio of gonad weight to body weight
increased most rapidly in the large war-
mouths (over 5.4 inches); males in this
group showed their greatest average gonad
weight in May and females showed their
greatest average gonad weight early in
June. The ratio of gonad weight to body
weight for both male and female war-
mouths between 3.5 and 5.4 inches in
length averaged highest the first week in
June. Soon afterwards, however, the ratio
of gonad weight to body weight declined
rapidly for females in the two larger size
groups. Among males of both groups,
there was a drop in weight of testes, but
the males remained sexually developed
later in the season than did females. The
ratio of gonad weight to body weight may
be at a minimum immediately following
cessation of sexual activity, but it may in-
crease slightly with reorganization of the
gonads.
Evidence from the cycle of changes in
the ratio of gonad weight to body weight
lends support to the conclusion previously
drawn that large warmouths mature ear-
lier in the season than do small ones and
also remain active reproductively over a
longer period. In this series of specimens,
initial ripening of the sex products oc-
curred during the second week in May,
1949, fig. 9.
At the time other warmouths were
spawning, warmouths under 3.5 inches
total length showed no increase in the rela-
tive weight of the gonads; in fact, an
apparent decrease took place. This decline
was probably associated with an improve-
ment in condition (an increase in the body
weight) of the smaller fish during May,
June, and July. The irregularities that
appeared during winter months in gonad
weight-body weight relationships of fe-
males in the two smallest length groups,
fig. 9, were attributed to changes in body
weight rather than to changes in gonad
weight; these irregularities corresponded
to changes in the coefficient of condition,
agg WE
Increasing length of day and rising tem-
peratures associated with spring are known
to stimulate gonad development in fishes.
34 ILtLino1is NATURAL History SURVEY BULLETIN
In 1949, the ratio of average gonad weight
to average body weight of Park Pond
warmouths began increasing early in
March and roughly corresponded to an up-
swing in mean monthly air temperatures
above 40 degrees F. (United States
——. FISH UNDER™ 3.5 IN.
FISH 3.5-5.4 IN.
FISH OVER 54 IN.
INTERPOLATION
GONAD WEIGHT 7 BODY WEIGHT, PER CENT
Vol. 27, Art. 1
Weather Bureau 1948-1949, Danville
Station). Spawning was actually initiated
at water temperatures (12 inches deep) of
about 70 degrees F. Low ratios of gonad
weight to body weight for the summer
months of July and August, 1949, indi-
90
80
WATER TEMPERATURE ed
70
60
50
im
=
40 ta
ac
=
ps
30 w
a
=
uJ
| ae
20
10
(@)
OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
1948
1949
Fig. 9—Curves illustrating the relationships of gonad weight to body weight (the per cent
the gonad weight is of the body weight) for male and female warmouths of three size groups
collected from Park Pond, early October, 1948, through early September, 1949, and water tem-
peratures (degrees F.) taken with a mercury thermometer 12 inches below the water surface.
August, 1957
cated that most of the spawning was com-
pleted by early July. Information obtained
from collections of warmouths made the
previous summer suggested that the spawn-
ing season in 1949 may have been shorter
than in most years.
Fecundity.— Probably one of the more
dificult problems in studying the repro-
duction of a fish is how to estimate the
total number of ova developed in a season
by an individual female. The problem is
especially complex in a fish that, like the
warmouth, spawns an indefinite number of
times over a rather long period and that
contains large numbers of eggs too small
to be counted without some magnification.
Usually an extended period of sexual ac-
tivity in fish is associated with a continu-
ous maturation of eggs and sperm, so that
sex products may ripen and be discharged
at frequent intervals during the spawning
season. Thus, at almost any time during
the spawning season, in the ovary are sey-
eral sizes of ova representing various
stages of development from primordial
germ cells to yolk-laden eggs ready for
spawning.
The egg-counting problem presented by
the warmouth was not solved by any of
the methods previously reported for de-
termining the number of eggs in fish ova-
ries. The method used—based on the dry
weight of the egg mass in an ovary—was
developed as an efficient way to estimate
the numbers of ova of various sizes. The
first step involved measuring several hun-
dred ova and sorting them into seven size
groups. A low power binocular microscope
(18) equipped with an ocular microm-
eter was used to measure each of the sev-
eral hundred ova to the nearest 0.05 mm.
The seven size groups were as follows: I,
0.15-0.30 mm.; II, 0.35-0.45 mm.; III,
0.50-0.60 mm.; IV, 0.65-0.75 mm.; V,
0.80-0.90 mm.; VI, 0.95-1.05 mm.; and
VII, 1.10 mm. and over. Group I in-
cluded most small ova except the undiffer-
entiated germ cells in the ovigerous lam-
ellae.
All ova diameters were measured as the
ova appeared at random on the horizontal
scale of the ocular micrometer. Clark
(1925:5), in using a similar system of
measurement, proved this was a reliable
method of measuring eggs that were not
spherical. The ova were separated into the
LarimoreE: Lire History oF THE WARMOUTH 35
various size groups as they were measured.
Twenty ova belonging to each size group
were then placed in a platinum crucible of
known weight and put in a drying oven at
45 degrees C. After remaining in the dry-
ing oven for 48 hours, the eggs, in the
crucible, were moved to a desiccator, where
they were left until repeated weighings
showed no changes in weight. (It is now
believed that the use of a desiccator was
not necessary.) Each sample was weighed
to the nearest 0.01 mg.; through calcula-
tions, the tentative average dried weight
for ova in each of the various samples was
determined. For each size group, five ad-
ditional samples of 20 eggs each were dried
and weighed before a final average dried
weight was determined. The average dried
weight determined for eggs in each size
group was assumed to be the same as the
average dried weight for eggs in a similar
size group in other ovaries.
Steps in processing each ovary for which
a calculation of egg numbers was desired
were as follows: (1) The connective tissue
sheath surrounding the ovary was removed,
and the eggs were teased apart; (2) a ran-
dom sample of several hundred eggs was
taken from the total mass of eggs in the
ovary; the eggs in the sample were meas-
ured individually and separated into size
groups, and the percentage of eggs in each
size group was determined; (3) the mass
of eggs remaining was washed, placed in a
drying oven at 45 degrees C. for 48 hours,
moved to a desiccator, and kept there until
repeated weighings showed no changes of
weight.
Steps in calculating the total number of
eggs in an ovary were as follows:
1. The average weight (dry) deter-
mined for eggs of each size group was mul-
tiplied by the percentage of eggs of the
random sample in that size group. The
products from the calculations for all the
size groups were added and the sum mul-
tiplied by 100 to give the calculated dry
weight of 100 representative eggs of the
sample.
2. The weight of the dried eggs (ex-
clusive of eggs in the random sample) was
divided by the calculated dry weight of
100 representative eggs, as determined
from the random sample, and the result-
ing quotient was multiplied by 100; to
this product was added the number of eggs
36 Ittino1is NATURAL History SURVEY BULLETIN
in the random sample. The sum of these
numbers was the calculated total number
of eggs in the ovary.
The calculated number of eggs in each
size group in the ovary was determined by
multiplying the calculated total number of
eggs in the ovary by the percentage of the
random sample represented by the size
group.
A modification of the dry-weight method
described above, and one that did not re-
quire the initial work of determining the
average dried weight of eggs of each size
group was as follows: After the eggs were
teased apart and the connective tissue
removed, (1) eggs in a random sample
were counted (and measured if there was
interest in size groupings), dried, and
weighed, (2) the eggs remaining were
dried and weighed, and (3) the total num-
ber of eggs was then calculated on the
basis of the total dried weight of all eggs
im the ovary including those in the ran-
dom sample. This method was similar to
that used by Katz & Erickson (1950176)
for estimating fecundity of herrings, in
which only one size group of eggs was
involved.
When the numbers of ova in only a few
ovaries are to be calculated, this modified
dry-weight procedure is faster than the
method first described. However, once
the average dried weight of ova of each
size group has been determined, the first
method requires less work and is faster be-
cause the sample ova that are measured,
sorted, and counted do not have to be dried
and weighed.
Ovaries for which estimates of num-
bers of eggs were made—38 ovaries from
Park Pond and 10 from Venard Lake—
had been divided into four groups: those
taken from Park Pond warmouths in (1)
January and March, (2) April, May, and
June, (3) July and August, and (4) those
taken from Venard Lake warmouths, May
25, 1949. In these ovaries, there was a pos-
itive correlation between estimated num-
bers of eggs in individual fish and total
length of fish. Coefficient of correlation
values ranged from 0.64 to 0.98.
Seasonal variations in the number of
eggs in warmouth ovaries were considera-
ble. There was a marked increase in num-
ber of eggs per ovary from late winter to
the peak of the spawning period, fig. 10.
Vol. 27, Art. 1
Immediately after the peak of spawning ac-
tivities, the number of eggs per ovary was
considerably reduced. At that time, the
correlation between number of eggs and
size of fish was lowest; this low correla-
tion was due to the depleted condition of
the ovaries, some of them being partly
spent, some entirely spent, and others part-
ly recovered. Females showing recovery
from spawning contained more eggs than
did the spent fish. During the fall and
winter months, the number of eggs per
ovary increased gradually; the final and
greatest increases took place in the spring
when groups of small eggs were adding
yolk and undergoing final maturation.
Fish of comparable sizes in different
bodies of water did not produce comparable
numbers of eggs. For example, a Venard
Lake female, 5.3 inches in length, con-
tained 40,400 eggs, whereas a female of
this length from Park Pond contained only
12,500 eggs, table 16. This large differ-
ence may be explained in part by differ-
ences in environmental stresses upon these
warmouth populations resulting from (1)
a rapidly expanding population in Venard
Lake in 1947 and 1948 in contrast to an
older and more stable population in Park
Pond, (2) a greater concentration of fish
in Park Pond than in Venard Lake, and
(3) a higher incidence of parasitic infesta-
tion in the more concentrated population
of fish.
Venard Lake was stocked in the spring
of 1947, and the fish population expanded
rapidly during the 1947 and 1948 growing
seasons. Although the population probably
had attained its maximum size by the time
ovaries were collected for egg counts in
1949, the rapid expansion of the popula-
tion in the preceding two seasons may have
been at least partly responsible for the fact
that the number of ova per female war-
mouth was greater for fish collected from
Venard Lake than for those from Park
Pond.
Park Pond had a higher population den-
sity of fish other than warmouths than had
Venard Lake, which had only warmouths
and largemouth bass. Where many fish
are concentrated within a limited volume
of water, there may be severe competition
for food and space among members of this
population. The smaller number of eggs
per warmouth in Park Pond may have been
ugust, 1957 Larimore: Lire History oF THE WARMOUTH 37
64
VENARD LAKE
o—— MAY, r=.88
it PARK POND
JAN-MAR r=.98
a—— APR-JUN r=.97
A--— JUL-AUG r=.64
48
40
AP riwvwvrivy
32
24
WUNVWDOLMN Wi Wve
tVIAu
2.0 3.0 4.0 5.0 6.0 7.0
TOTAL LENGTH OF FISH, INCHES
Fig. 10—Estimated number of ova from warmouths of various total lengths in collections
from Park Pond (January-March, April-June, and July-August) and Venard Lake (May),
1949. Scattergram, regression line, and coeficient of correlation (r) are given for each collec-
tion group. Elevations of the regression lines indicate seasonal changes in numbers of ova in
three groups of Park Pond warmouths and also indicate that females from Venard Lake pro-
duced more ova than did females of similar sizes from Park Pond. Each graphic symbol repre-
sents one female from which the number of ova was estimated.
38 Inutinois NarurAL History SurvEY BULLETIN Vol. 27, Art. 1
associated with interspecific competition were in much better body condition (aver-
among several species rather than intra- age of coefficient of condition 82.2) than
specific competition among warmouths. were Park Pond females of similar sizes
Of the warmouths for which ova counts taken at about the same time (average of
were made, the females from Venard Lake coefficient of condition 73.8). This differ-
Table 16.—Estimated numbers of ova in 38 warmouths from Park Pond and 10 from
Venard Lake, 1949, arranged according to seasons and in order of increasing total length of fish.
’ EstTIMATED
LENGTH OF WEIGHT OF DaTeE OF
PLACE AND TIME Fisu, IncHEs FisH, Pounps CoLLECTION Bie is at
Park Pond, 4.4 0.06 March 2 8,100
January-March 4.7 0.07 March 2 10,200
Sal 0.09 March 2 11,200
Dye 0.11 March 2 12,300
523 0.11 March 2 12,500
Eee 0.13 January 8 15,600
6.4 0.21 January 8 24,300
6.6 0.24 January 8 23,400
Park Pond, 3.5 0.03 May 23 4,500
April-June 3.6 0.03 April 9 6,200
4.1 0.05 May 13 10,200
4.3 0.05 April 9 9,800
4.6 0.06 May 14 11,200
4.8 0.09 May 13 11,200
510 0.09 April 7 17,700
5A 0.10 May 13 11,600
sit 0.10 May 14 12,000
5.4 0.12 May 13 13,900
5.5 0.13 May 13 15,500
526 0.12 June 10 17,900
5.6 0.14 April 9 22,200
St 0.15 June 10 18,300
5.8 0.15 June 10 26,000
5.8 0.15 May 13 25,600
5.9 0.16 May 13 21,200
6.0 0.18 May 14 25,500
6.1 0.18 May 13 30,400
6.2 0.17 May 14 23,700
6.4 0.20 June 3 31,900
6.9 0.28 May 14 32,700
cai 0.29 June 10 37,500
Park Pond, 5S 0.12 August 1 11,000
July—August 5.6 0.14 August 15 15,100
ae | 0.15 July 5 13, 100*
6.2 0.20 July 8 16,200
6.3 0.16 July 5 11,300**
6.6 0.24 August 15 19,800
6.7 0.24 August 1 16,100
Venard Lake, Ba 0.04 May 25 17,200
May 4.1 0.06 May 25 31,400
4.2 0.06 May 25 30,200
4.3 0.06 May 25 26,000
4.4 0.07 May 25 28,200
4.4 0.07 May 25 29,000
4.6 0.08 May 25 31,600
ae! 0.11 May 25 57,000
S50 0.12 May 25 40,400
5.4 0.14 May 25 63,200
*Two plerocercoids of Proteocephalus.
**Four plerocercoids of Proteocephalus.
August, 1957
=nce in body condition indicated that the
Venard Lake females had a greater amount
yf reserve energy, which was available
ror the production of eggs.
Functions of the gonads of warmouths
may be disturbed by internal parasites.
Iwo ovaries in the series examined were
yarasitized by plerocercoid tapeworms and
-ontained fewer ova than expected, table
'6. However, in both Park Pond and Ven-
ird Lake there was such a high correlation
yetween egg production and length of fish,
‘egardless of differences in parasitic infes-
ations, that it does not seem possible that
yarasites greatly influenced egg production
n these populations.
Fecundity in warmouths may be re-
luced by lack of suitable nesting space, by
yvercrowding of the population, unfavor-
ible weather conditions, or other circum-
tances which limit spawning opportunities
ind result in large numbers of mature eggs
yeing retained and resorbed in the ovaries.
“xamination of ovaries from warmouths
aken from Park Pond during the middle
ind last of June, 1949, revealed that only
mall percentages of mature eggs were
yresent in these fish and that some of these
zgs were being resorbed, indicating that
\ot all the ova produced were actually dis-
harged. It was found that the spawning
eriod for warmouths was generally
horter in this water area than in other
vater areas under observation in I[Ilinois.
Seasonal Development of Ova.—
Jevelopment of warmouth ova through
he seasons was observed in the fish col-
ected from Park Pond, figs. 11 and 12.
[he development was followed by assign-
ng the ova collected at various times to
he size groups defined on page 35. The
easonal occurrence of eggs in these size
‘roups was as follows:
1. From January to early April, ova-
ies contained only the smallest eggs (size
roup I, 0.15—0.30 mm. diameter).
2. During the second week in April, the
va began to increase in size; some ova
vere in group II.
3. By the middle of May, in some fish
wo-thirds of the eggs were of the smallest
ize, or size group I, and small numbers of
ggs were in size groups II, III, IV, and
/. In other fish only one-third of the eggs
vere in size group I, and group VI, as
vell as groups II, III, IV, and V, was
LarimMoreE: Lire History oF THE WARMOUTH 39
represented. In still other fish, there were
relatively more eggs in groups V and VI
than in groups II, III, and IV.
4. Toward the end of May, all of the
size groups of ova were well represented,
and some of the eggs appeared to be ripe.
5. By the end of the first 2 weeks of
June, the ovaries of all the mature fish had
discharged most of the largest eggs. Some
of the fish appeared to be preparing for a
final spawn; about one-fourth of their eggs
were in size group V and only low per-
centages in groups II, III, and IV. Other
fish appeared to have completed spawning,
and their ovaries appeared to have begun
reorganizing, as small eggs again com-
prised three-fourths of the ova present.
6. On completion of spawning in July
or early August, ovaries contained many
pulpy eggs that were undergoing rapid re-
sorption; the only other eggs present were
those of group I. The ovigerous lamellae
were poorly organized, showing no recov-
ery from the production and crowding of
large volumes of mature eggs.
7. By mid-August, ovaries were fully
reorganized; the well-arranged ovigerous
lamellae contained many small ova which
comprised a part of the egg-stock for the
next season.
Prespawning Activities
Nest building and spawning activities of
the centrarchids probably have been stud-
ied more thoroughly than the spawning be-
havior of any other family of fishes (Bre-
der 1936 and others). Although the repro-
ductive behavior of the warmouth is much
like that of other sunfishes, it may differ
in the location and construction of nests,
recognition of sex, courtship, care of eggs
and larvae, and spawning schedule.
Location and Construction of
Nests.—Warmouths appear to exercise
selection in their choice of nesting sites.
Both available bottom materials and cover
influence this selection. In Venard Lake,
where nesting was easily observed, the fol-
lowing types of bottom were available:
loose silt, silt containing sticks and leaves,
rubble, rubble covered with a thin layer of
silt, sand with loose silt, and clean sand.
No nests were found on clean sand (such
as is often selected by bluegills and pump-
kinseeds), and the only nests seen on loose
40
silt were closely associated with tree roots
or mats of submerged plants. Even though
the Venard Lake warmouths used each of
the bottom types (except sand) as nesting
sites, they showed some preference for rub-
ble lightly covered with silt and detritus.
The warmouths at Venard Lake were
not so consistent in nesting on a particular
kind of bottom as they were in selecting a
spot near a stump, root, rock, clump of
100
~J
on
JAN. 8
3 Fish |
MARCH 2
5 Fish
APRIL 9
3 Fish
oO
oO
Mm
ol
5
PER CENT OF TOTAL NUMBER OF OVA
ol
oO
25
III seme | ee I
ILLiNois NATuRAL History SURVEY BULLETIN
Vol. 27, Art. 1
vegetation, or some similar object. This
habitual preference for a location adjacent
to a stationary object may account for the
lack of nests on the clean sand bottom in
Venard Lake. Nests were never found on ~
an area of bottom completely exposed, such
as the bluegill usually selects. In labora-—
tory aquariums, the locations most often —
used by warmouths for nesting were near
the vertical drain pipes.
APRIL 9
Fish
V Vil | I
SIZE GROUP OF OVA
Fig. 11.—Percentage of total number of ova in each size group of ova found in warmouths
collected from Park Pond and Venard Lake, January 8 to May 25, 1949.
August, 1957
In Park Pond, warmouths nested among
weed masses, stumps, roots, and brush;
they nested in areas where the water was
less than 4 feet deep and were most fre-
quently seen where the shale and rubble
spread out at the ends of the old spoil banks
or had filled in the back portions of the
flooded strip channels. ‘They were not seen
nesting where the banks were steep and
sloped off quickly into deep water.
100
~J
ol
oO
oO
ine)
ol
JUNE 10
3 Fish
Pen UENT OF 1ClBL~ NUMBER OF (OVA
25
| ti Mia Mies | Il
LarimorE: Lire History oF THE WARMOUTH
41
Warmouths build nests within a wide
range of water depths, and consequently
nest locations vary in their distances from
shore. Earlier observers of warmouths re-
corded a variety of water depths selected :
6 to 10 inches (Richardson 1913: 412) ;
mostly 2 to 10 inches (Carr 1940:109) ; 3
feet (Hubbs 1919: 144); 2 or 3 feet
(Toole 1946: 33). In Venard Lake, the
depths of water over warmouth nests that
JULY 5,8
3 Fish
AUG. 1,15
4 Fish
V Vil | HI V
SIZE GROUP OF OVA
Fig. 12—Percentage of total number of ova in each size group of ova found in war-
mouths collected from Park Pond and Venard Lake, May 25 to August 15, 1949.
42
were found ranged from 6 to 60 inches.
Most of the nests were covered with 2 to
2.5 feet of water; nests in deeper water
were more difficult to locate and may have
been more common than counts showed.
The limited areas of shallow water or the
high transparency of the water in Venard
Lake might account for the comparatively
great depths at which nests were found in
this body of water.
Reports of some observers indicate that
the warmouth is gregarious in its nesting
habits, forming colonies of nests (Richard-
son 1913:412; Carr 1940:110). It seems
probable, however, that colony formation
is a result of restricted nesting habitat.
Observations of Carr (1940:109) in Flor-
ida and of the author in Il]linois support
the assumption that the reason warmouth
nests are sometimes found close to each
other is that the fish are tolerant of each
other rather than gregarious in their
habits. The warmouth colony studied by
Carr was formed on what may have been
the only bottom of suitable depth not cov-
ered with ooze. In Venard Lake, in May
and June, 1947, nests were scattered in
shallow water along the shore line with no
indication of colonization. Three nests
within a linear distance of + yards were
the only ones that were found very close
together.
Nest construction by warmouths in lab-
oratory aquariums was observed many
times in the course of the study reported
here. As in other sunfishes, the male ex-
cavates the nest. Violent sweeping motions
of the tail clear the loose debris away from
the selected spot and produce a shallow,
irregular concavity. The male begins each
sweeping movement by approaching the
nesting spot with his nose low and close
to the bottom. As he enters the nest site,
he turns abruptly upward, giving three or
four violent sweeps with his tail while bal-
ancing in an almost vertical position and
checking his forward motion with his pec-
toral fins. The loose material in the nest
area is stirred up, and much of it settles
outside the spot being cleared. The size
and neatness of the nest depend to some
extent on the amount of time the male
spends in its construction. Many nests in
natural waters are rather shapeless oval de-
pressions of 4 by 8 inches from which loose
silt has been cleared. The male may con-
Ituinors NaturAL History SurvEY BULLETIN
Vol. 27, Art. 1
tinue to improve the nest if a female is not
immediately available for spawning. One
warmouth male nesting in an aquarium
worked on his nest until it was a beauti-
fully symmetrical depression 18 inches in
diameter and 5 inches deep. Though most
warmouth males under natural conditions
spend no more than a few hours in clear-
ing small nesting spots, the male in the
aquarium spent a week working on his nest
while waiting for the female that was
present to become ripe.
A mature female warmouth isolated in
an aquarium during the breeding season
constructed a shallow nest; her attach-
ment to the nest was much weaker than
that characteristic for a male.
Preliminary Courtship.—The pre-
liminary courtship phase of warmouth
nesting was observed by the author only
in laboratory aquariums. Normally it ap-
peared as an aggressive threat to other
males, serving to drive them away, and as
a persuasive gesture to females in spawn-
ing condition.
During the first week in May, 1947,
three unripe warmouths were placed in
ee
each of four aquariums previously filled —
with water and supplied with a layer of
sand and gravel. By the second day, some —
of these fish had selected favorite corners
and were accepting food. Two of the three —
fish in each tank soon began constructing
nests and making advances at the third
fish. On the basis of behavior, only the
nest-building warmouths appeared to be
males; the third fish in each of the tanks
showed no interest in nesting and appar- —
ently was being courted by the aggressive
males. Courtship in each tank progressed —
to the act of driving the nonnest-building
warmouth into the nest depression and go-
ing through motions of spawning. Vivid
spawning colors (discussed in the follow-
ing section) were displayed by only the ag-
gressive males; no color changes were
shown by the fish that were being courted. —
After these courtship activities had con-
tinued for several days, the fish were ex-
amined. Several had become ripe since be-
ing put in the aquariums and were flowing
milt. Dissection of the nonaggressive, non-
nest-building fish revealed that they, too,
were males, although not in advanced
stages of development, as were the aggres-
sive males.
August, 1957
These initial observations of spawning
suggest that (1) warmouth males begin
construction of the nests in the absence of
females and well before their testes are
ripe; (2) sex recognition among war-
mouths is based on behavior and response
to courting; and (3) in a small group of
warmouths, during the breeding season
some individuals assume dominance over
less aggressive fish.
When a female that is not yet ready to
spawn is placed in a tank with a nesting
male, she is charged, nipped, and driven to
the surface. She remains quiet and retir-
ing, ignoring as much as possible the male’s
advances. Being unable to escape the male
in an aquarium, she may finally be killed
by his continued aggression. Under nat-
ural conditions, the female does not become
exposed to the unavoidable advances of
the nesting male before she is ready to
spawn.
Spawning
In the warmouth, the mating act, which
includes the deposition and fertilization of
eggs, requires the simultaneous ripening
ot sex products and synchronization of be-
havioral attitudes in a male and female.
Many environmental conditions, as well
as the state of maturity of the fish, affect
the spawning process.
Size and Age at Sexual Maturity.
—The attainment of sexual maturity in
fishes is influenced by both age and size.
In the warmouth, size seems to be more
important than age in determining when
a fish attains maturity. However, there is
considerable variation among warmouths
in the size (and age) at which maturity is
reached. As might be expected, this vari-
ation is greater between fish of different
populations than among fish within a sin-
gle population.
Sexual maturity is attained by war-
mouths when the fish are between 3 and 4
inches in length. In Venard Lake, both
males and females matured at 1 year of
age and at lengths between 3.1 and 3.4
inches. In Park Pond, warmouths did not
mature until they were 2 years old and at
least 3.5 inches in length. Thus, at the
time the fish became sexually mature in
Park Pond, they were somewhat larger
than the sexually mature 1-year-old fish in
Larimore: Lire History oF THE WARMOUTH 43
Venard Lake. Hile (1941:319) found for
the rock bass that rapid growth appears
to be correlated with an early attainment
of sexual maturity.
Nesting Season.—The observed nest-
ing season for the warmouth in central
Illinois begins during the second week in
May, reaches its peak early in June, starts
to decline after the first of July, but often
extends well into August. The length of
the nesting season differs among different
populations of warmouths in different lakes
and probably varies considerably from year
to year. The length of the season varies
also with the size of the fish; large war-
mouths spawn over a longer period than
do small ones, fig. 8.
Although the exact length of the spawn-
ing season is difficult to determine for an
individual fish, studies of gonads have
shown that a fish may spawn several times
during a summer. In ‘Texas, ‘Toole
(1946:33) reported, “One pair of these
fish was observed to spawn three different
times during one year from April to Octo-
ber.” At the Natural History Survey lab-
oratory, two females that spawned early
in June, 1948, were examined 2 weeks
later and were found to have well-devel-
oped ova. These fish were not spent after
the one spawning period and would un-
doubtedly have produced more ripe eggs
during the same season. Warmouths that
were collected in July, 1948, and that pre-
sumably had spawned at least once, were
placed in a small pond on the following
August 10; they produced a good brood of
young in the pond that season.
Deposition and Fertilization of
Eggs.—Only when a female is ready to
lay her eggs will she allow a male to guide
her to the nest for spawning. In getting
the female to the nest, the male assumes a
very aggressive attitude, approaching her
with his opercles widely spread and _ his
mouth open. ‘The body of such a courting
male becomes bright yellow in color and
his eyes become blood red. The adjust-
ment to these colors is very rapid, requir-
ing only 5 to 10 seconds. If the female is
ready to spawn, she is easily directed to-
ward the nest, and spawning soon follows.
The number of females contributing to
the complement of eggs in a nest may de-
pend upon how many females are ripe and
available to the male. It is probably not
44 Ittinors NAturRAL History SuRVEY BULLETIN
uncommon for more than one female to
spawn in a single nest, as has been observed
for other centrarchids. That such polyg-
amy seldom occurs after the male assumes
close guardianship of the eggs is indicated
by the fact that freshly laid eggs are not
commonly found in nests containing eggs
in advanced stages of development. In a
laboratory aquarium, however, a male
guarding yolk-sac fry brought a female to
the nest and proceeded with spawning ac--
tivities.
One female observed in a large aquarium
in which two males had nests only 10
inches apart alternated between the two
nests during a continuous spawning se-
quence. During an hour of spawning ac-
tivity, the female spawned with both
males. When she was in one nest, the
male in the other nest showed no concern
for her; he would inspect the newly depos-
ited eggs, stir the nest with his tail, and
wait for the female to again approach his
nest. The female spawned almost contin-
uously for 40 minutes and for another 20
minutes at brief intervals and less vig-
orously. When spawning was finished, the
female was temporarily removed from the
ee c
- ae
PE oe oe
_ a a: ‘3
a ir :
Ban ge
Fig. 13—Warmouths spawning in an aquarium. The light-colored fish is the male; the
darker fish below and slightly on her side is the female.
Vol. 27, Art. 1
aquarium; gentle pressure on the sides of
this female did not cause the discharge of
any eggs.
On entering the nest site, both male and
female begin to circle, the female being
nearer the center of the nest, slightly on
her side and somewhat beneath the male, —
fig. 13. As they circle inside the nest, the
female works her jaws three or four times
and suddenly jerks her body violently, giv-
ing the male a sharp thump on the side.
Each time the female jerks, she extrudes
about 20 eggs. The thump she gives the
male probably stimulates a discharge of
sperm, although no milt was ever seen —
coming from the genital pore. After cir-
cling the nest several times, the female
interrupts the activities and leaves the nest
site. The male usually follows her a
short distance but returns quickly to the
nest to assume guardianship. At this point
in the spawning activity, males often have —
been observed to fan the nest with sweep- —
ing motions of the tail in a manner similar ©
to that exhibited when nest building.
Spawning activities like those observed
in aquariums were carefully watched in
Venard Lake. In nature, when a female
August, 1957
is ready to spawn, she makes her appear-
ance near a nest and accepts the advances
of the male. After a few spawning turns
inside the nest, she retires, usually to a
clump of weeds several yards away. The
' male remains over the nest for a few min-
utes before again making advances toward
the female. This procedure is repeated un-
til the female has discharged her ripe eggs.
With spawning completed, the female
swims away, and the male settles down
quietly to protect and fan the eggs.
History of Embryos and Larvae
When the warmouth starts its life and
development, it is confronted by greater
stresses of physical and biological factors
than it will face at any other time during
its life. “Temperature changes or tempera-
ture extremes, disease and predation, and
dependence on the constant protection of
a parent fish, which may at the same time
be exposed to many dangers, result in high
losses in the period of early development
of the warmouth.
Development of Embryos.—Four
groups of warmouth eggs, 10 in each
group, were artificially inseminated in or-
der to observe the gross development of the
embryos and the exact length of the incu:
bation period. The following account in-
cludes the time sequence of certain easily
discerned stages of development at tem-
peratures between 25.0 and 26.4 degrees
C. Within this temperature range, the
average developmental period of the 40
eggs was 34 hours and 3() minutes and the
interval between hatching of the first egg
and hatching of the last was 2 hours and
40 minutes. ;
When eggs and sperm were mixed in a
petri dish and then immediately flooded
with water, a high percentage of the eggs
became fertilized. The inseminated eggs
measured ().95 to 1.03 mm. in their great-
est diameters during their first and second
minutes in water. These measurements are
slightly below those of the largest ova
taken from preserved ovaries. Differences
in size measurements between preserved
and live ova may have been due to differ-
ences in shapes: irregular shapes of the ova
preserved intact in the ovaries and almost
spherical forms of the live ova in water.
Each of the live eggs, translucent and light
Larimore: Lire History oF THE WARMOUTH 45
amber in color, contained a single, dark
amber oil droplet 0.35 mm. in diameter.
Within 3 minutes after an egg was im-
pregnated by a sperm cell, a thin perivitel-
line space could be seen between the outer
membrane (chorion) and the egg cell
proper. Thirty minutes later, a blastodisc
was evident as a slightly raised cap, giving
the egg a somewhat oval appearance. The
first division of the blastodisc occurred 43
minutes after impregnation. Each blasto-
mere then measured 0.4 mm. across. The
second, third, and fourth divisions took
place at 60, 75, and 90 minutes, respec-
tively. The resulting group of blastomeres
appeared whitish, the yolk was very pale
yellow, and the oil droplet remained dark
amber in color.
After 2 hours and 15 minutes, the blas-
tomeres formed an oval-shaped mass at one
end of the yolk. The segmentation cavity
was formed beneath this mass, and at 2
hours and 30 minutes the blastoderm be-
gan growing down over the yolk mass.
The blastoderm had grown over two-
thirds of the yolk mass within about 11
hours after impregnation, and a thickened
band of cells at the margin of the blasto-
derm had appeared as the germ ring. About
an hour later (12 hours and 15 minutes
after impregnation), the blastoderm cov-
ered all but a small plug of yolk, which
contained the oil droplet. The first differ-
entiation among the dividing cells was visi-
ble in the live egg after 14 hours and 15
minutes. A groove extended around the
ege from a patch of opaque cells near
where the yolk plug and oil droplet en-
tered the blastoderm. This groove, formed
by the neural plate and neural folds, be-
came quite distinct during the following
hour (15 hours and 10 minutes after im-
pregnation).
After 16 hours and 30 minutes, the
primordial form of the embryo was de-
fined. The ensuing process of organ for-
mation, however, could not be discerned.
Movement of the embryo was first ob-
served 25 hours after impregnation.
The first egg hatched 33 hours and 20
minutes after impregnation. All eggs had
hatched by the end of the following 2
hours and 40 minutes (36 hours after im-
pregnation). Fry emerging from the eggs
early during the hatching period were
smaller (2.30-2.60 mm. in total length)
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August, 1957
than those emerging later (2.65—2.85 mm.
in total length). The oil droplet in the
newly hatched fish was the same size (0.35
mm. in diameter) and color as it was in the
newly fertilized egg. The greatest depth of
the fry was 0.80 mm. across the yolk sac.
It is interesting to note here that war-
mouth eggs fertilized with sperm from a
green sunfish showed no difference in rate
of development from the rate described
above. There was a high percentage of
survival of both embryos and fry of the
warmouth and green sunfish cross.
Development and Growth of Lar-
vae.—Specimens for a study of growth of
larvae were collected from a nest in a lab-
oratory aquarium. ‘The eggs were laid dur-
ing the morning of June 24, 1947. Daily
collections were made until the postlarvae
left the nest. ‘Then the free-swimming lar-
vae were transferred to an outdoor tank,
where observation and sampling were con-
tinued. The specimens, preserved in alco-
hol, served as materials for the following
descriptions of developmental stages. Ob-
servations indicated that total length of a
larva is a better indicator of the stage of
its development than is actual age, which
was known for each specimen. Measure-
ments made with an ocular micrometer to
the nearest 0.01 mm. were used in the de-
scription of body form. In general, de-
scriptions follow the procedure used by
Fish (1932) ; terms for growth stages are
those suggested by Hubbs (1943: 260).
Prolarva, 3.4 mm., soon after hatching,
fig. 144: Total length 3.4 mm.; length to
anus 1.7 mm.; length of yolk sac 1.0 mm.
Large oval yolk mass containing one oil
droplet 0.3 mm. in diameter. Head de-
flected sharply downward in front of yolk
sac, making the midbrain the most forward
part of the body and the forebrain lying
directly beneath it. Head from front of
forebrain to end of hindbrain 0.65 mm.
Optic capsule faint, 0.23 mm. in diam-
eter. Notochord straight. Myomeres in-
complete anteriorly, numbering about 8 in
front of anus and 17 behind anus. Embry-
onic marginal fin fold complete except for
faint break where intestine penetrates fin
to outside. Fin extending forward on back
to point 1.0 mm. from front of body. No
visible ray development nor pigmentation.
Prolarva, +.6 mm., 48 hours old, fig.
14B: Total length 4.6 mm.; length to
Larimore: Lire History oF THE WaRMOUTH 47
vent 2.0 mm.; length of head 0.63 mm.;
greatest depth of body in front of vent 0.70
mm.; greatest depth of body behind vent
(excluding fin fold) 0.35 mm. Forebrain
still somewhat deflected, with globular
cerebellum extending high above anterior
part of medulla. Eyes well pigmented.
each 0.35 mm. in diameter; optic fissure
still quite apparent. Mouth indistinct. Fin
fold extending forward on back to point
1.2 mm. from front of body, entire except
for break at anus. Very weak indications
of fin rays below and above end of straight
notochord, giving effect of diphycercal tail.
Pectoral lobes present. Myomeres indis-
tinct forward, about 10 to anus, 19 caudad
from anus. Branchial elements forming.
Postlarva, 5.3 mm., 4 days old, fig.
14C: Total length 5.3 mm.; length to anus
2.2 mm.; greatest depth of body anterior
to anus 0.6 mm.; greatest depth of body
posterior to anus 0.35 mm.; diameter of
eye 0.41 mm.; length of head 0.90 mm.
Cranial flexures almost straightened, but
cerebellum high and bulblike. Optic cavity
distinct. Fin fold beginning on back 1.5
mm. from front of body, becoming slightly
narrow on caudal peduncle but wide again
at tail. Faint indication of rays forming
in areas of the anal and soft dorsal fins.
Distinct fin rays on either side at end of
the straight notochord. Kidney apparent
through body wall. Pectoral fin lobes well
developed but with no rays. Myomeres 10
anterior to anus, 19 posterior to anus.
Branchial arches well formed and with de-
veloping gills. Mouth gape extending
obliquely forward from point below mid-
dle of eye. Dark row of spots on either
side of ventral fin fold; two large chro-
matophores between bases of pectoral fins.
Postlarva, 7.6 mm., fig. 14D: Total
length 7.6 mm.; length to anus 3.4 mm.:
length of head 1.5 mm.; diameter of eye
0.55 mm.; greatest depth of body anterior
to anus 1.15 mm.; greatest depth of body
posterior to anus 0.65 mm. Myomeres 11
before anus, 19 behind anus. Fin fold still
complete except for break at anus; high at
soft dorsal fin region, quite low above and
below caudal peduncle. End of notochord
bent upward at 40-degree angle, giving ap-
pearance of heterocercal tail. Caudal fin
rays well developed on lower side of noto-
chord, with middle rays longest. Rays
weak but distinct in unformed anal fin;
48 Ittrnois NaTturRAL History SurRvEY BULLETIN
rays very weak in soft dorsal. Rays visible
in pectoral fins. Mouth only moderately
oblique. Pigmentation much more devel-
oped. Row of spots along ventral fin fold
spreading as stellate chromatophores over
ventral surface of body. Series of dark
dashes indicating lateral line. Heavy chro-
matophore lying above anus. Some color
apparent at base of caudal fin rays. Six
stellate chromatophores between bases of
pectoral fins and a row of five chromato-
phores on each side across branchiostegals.
Distinct, dark chromatophores scattered
over top of head.
Postlarva, 8.8 mm., fig. 14£: Total
length 8.8 mm.; length to anus 3.9 mm.;
length of head 2.0 mm.; length of snout
0.4 mm.; diameter of eye 0.75 mm.; depth
of caudal peduncle 0.65 mm. Caudal pe-
duncle long and narrow. Notochord with
upturned end but tail appearing essentially
homocercal. Fin fold present immediately
anterior to anus. Anal and soft dorsal fins
separate from caudal fin but each broad at
base, due to some remaining parts of the
embryonic marginal fin fold. Rays distinct
in all fins present. Pelvic fins not devel-
oped. Otic region large and clear. Anus
protruding from ventral line of body. Lat-
eral line chromatophores quite distinct.
Ventral spots larger, with more chromato-
phores scattered over head region.
Postlarva, 12.0 mm., fig. 14F: Total
length 12.0 mm.; length to anus 5.4 mm. ;
length of head 2.8 mm.; diameter of eye
1.0 mm.; length of snout 0.7 mm.; great-
est depth of body 2.45 mm.; length of cau-
dal peduncle 2.4 mm.; depth of caudal
peduncle 1.15 mm. Fin fold remaining
only as short keel in front of anus. Pelvic
fins present but weak and with indistinct
rays. Spinous dorsal developed only as a
row of short stubs. Distribution of pig-
ment about the same as in 8.8 mm. stage,
except spots appearing more distinct. More
dark chromatophores around mouth; a ver-
tical row present at base of caudal rays.
Juvenile, 15.7 mm. (not photographed ).
Body form essentially like that of adult
fish. Total length 15.7 mm.; length to
anus 7.0 mm.; length of head 4.35 mm.;
diameter of eye 1.4 mm.; length of snout
0.85 mm.: greatest depth of body (at about
anterior insertion of spinous dorsal) 3.7
mm.; length of caudal peduncle 2.9 mm.,
depth 1.5 mm. Anus protruding only
Vol: 27; Art. I
slightly from abdomen. No trace of em-
bryonic marginal fin fold. Pelvic and spi-
nous dorsal fins well formed. Pigmentation
much heavier than in earlier stages. More
color apparent over head and caudal pe-
duncle. Belly rather free of pigment. Many
large chromatophores scattered over back.
Heavy row of spots forming circle behind
eye and distributed over top of head. Chro-
matophores noticeable on soft dorsal, anal,
and caudal fins.
Behavior of Larvae.—Activities of
the warmouth larvae during their early life
in the nest were limited to a few feeble
movements. here was definite sequence,
however, in the behavioral development of
these small fish. The following description
of behavior was based on laboratory ob-
servations in aquariums with water of
24-25 degrees C. (75-77 degrees F.).
Immediately upon hatching, the delicate
prolarvae dropped down onto the sand and
silt between coarse gravel particles of the
nest. As the heavy yolk sac restricted
movement, the prolarvae were difficult to
see in the nest. When the prolarvae were
between 36 and 48 hours old, fig. 14B, they
began making feeble jumps an inch or so
above the bottom of the nest. Most of
these prolarvae were between gravel par-
ticles in the nest, but a few could be seen
resting on the flat surfaces of the largest
particles.
Although the yolk supply was about ex-
hausted by the fourth day, the young fish
still limited their movements to poorly di-
rected jumps above the nest. They did not
begin active swimming until the end of
the fifth day, when they appeared as in
fig. 14D. At this time, they swam about
the nest in rather compact groups. Their
movements were well controlled, and they
showed remarkable ability to avoid a dip
net. In the aquariums, these small fish had
no food supply and starved in 10 or 11
days after hatching, but in outdoor tanks
they began feeding at least by the seventh
day after hatching.
School formation among postlarval war-
mouths in natural habitats was not so ob-
vious as in postlarvae of certain other
sunfishes, for the warmouths remained
either among dense submerged vegetation
or else in small pockets of open water
closely surrounded by plants. The indi-
vidual shown in fig. 14F was taken from a_
_— OO
August, 1957
school near the nest in which it had
hatched. The schools gradually dissolved
as individuals began independent searches
for food. No juvenile warmouths were
observed in large groups.
Factors Affecting Survival.—Rate
of survival of warmouth eggs and young
is influenced greatly by many physical and
biological factors. Incubating eggs are
readily affected by adverse weather condi-
tions. Sudden drops in water tempera-
tures promote the rapid growth of fungi
infecting the eggs; often, entire nests of
eggs are destroyed early in the spawning
season as a result of low temperatures and
fungi. For example, many warmouth nests
in Venard Lake contained eggs during the
last week in May, 1947, but, after several
days of cold weather, the eggs in every
nest observed were covered with fungi.
Although heavy rains and high turbidity
were not seen to affect nesting of adults or
survival of fry, rapidly falling water levels
might disturb nesting:
In several Illinois lakes, minnows and
sunfishes were observed destroying eggs
and larvae in unprotected warmouth nests.
In laboratory aquariums, warmouths were
seen to rob poorly guarded nests; they
charged in to snap up eggs or larvae.
Postlarval and juvenile warmouths
which have left the nest are eaten in great
numbers by larger fish. Venard Lake sup-
ported a heavy spawn of both largemouth
bass and warmouths in the summer of
1947. On June 30 of that year, bass 1.75
inches long were voraciously feeding upon
warmouths 0.75 inch long, which had
been eating large numbers of postlarval
warmouths. In the laboratory, a 0.75-inch
warmouth ate 11 postlarvae (4 days old)
in 5 minutes; another ate 12 in the same
length of time.
Survival of small warmouths is closely
related to the density and composition of
the fish population, the time of year, and
the character of the habitat in which they
are produced. Fry hatched late in the
spawning season are in a population with
a larger number of potential predators
(fish only slightly larger than themselves)
than are the fry produced earlier. How-
ever, because the density of aquatic vegeta-
tion increases during June and July, sur-
vival in the late summer broods is fre-
quently higher than in early broods.
Larimore: Lire History oF THE WaARMOUTH 49
GROWTH
Whether one is studying a single spe-
cies of fish or the entire fish population of a
body of water, it may become necessary to
consider the growth of individuals in the
one or more species involved. An analysis
of growth is not always the objective of
such a study, nor is determination of the
morphological relationships which must be
known before an analysis of growth can be
made. The ultimate value of a growth
study may come from its use in deter-
mining the factors that govern or influence
growth of fish under particular conditions.
Relative Growth
Various parts of a fish’s body grow at
differential rather than uniform rates. The
differential rates are not necessarily the
same even for closely related species in the
same habitat, nor for fish of the same spe-
cies in different habitats. Consequently,
when making a growth analysis of a se-
lected species in a given habitat, one must
determine several morphological relation-
ships, namely, those of body growth to
scale growth, body growth to growth of
tail fin, and growth in length to growth in
weight. Lewis & English (1949) and
Hennemuth (1955) have plotted some of
these relationships for two populations of
Iowa warmouths, and Jenkins, Elkin, &
Finnell (1955) for several populations of
Oklahoma warmouths.
Relation of Body Growth to Scale
Growth.—A regression line to show the
relationship between length of anterior
radii of scales and length of body was con-
structed from measurements of 1,068 war-
mouths from Venard Lake and Park Pond,
fig. 15. Data were obtained from collec-
tions made approximately monthly begin-
ning in June, 1948, and ending in Novem-
ber, 1949. Regression lines constructed
for warmouths from Venard Lake and for
those from Park Pond proved to be so
similar that data from the two lakes were
combined.
Key or representative scales were taken
from the side of each of the fish near a
point where the tip of the pectoral fin laid
backward touched the third row of scales
below the lateral line. Fish were sep-
arated into total length classes at 0.5-inch
50
m N re)
[e) oO oO
oO
(o)
ow
fo)
41 X ANTERIOR RADIUS OF SCALE IN INCHES
rm iS
° re)
°
lO 20 30 40 50 60 70 80 90
TOTAL LENGTH OF FISH IN INCHES
Fig. 15.—Regression line expressing the re-
lationship between total length of fish and
radius of scale for 1,068 warmouths collected
from Park Pond and Venard Lake, early June,
1948, through middle November, 1949. The
dots show the anterior radius of scale X41 for
fish of various total lengths (one-half-inch
intervals).
intervals, and the average of the total
lengths for the fish in each of these classes
was determined. Scales of these fish were
placed in a scale-reading machine that
magnified 41 times, and images of the an-
terior radii of the scales were measured
and averaged for the fish in each length
class. Average total lengths of fish and
corresponding average anterior radii of
selected scales were used in developing
I_ttinois NaturAL History SurRvEY BULLETIN
Vol. 27, Art. 1
the regression line shown in fig. 15 and
the following equation:
L=0.5278+ 1.048 §
where L=total length of fish in inches
and S41 anterior radius of scale
in inches
Relation of Body Growth to Tail
Growth.—Growth of the body of a fish in
relation to growth of its tail, or caudal fin,
may be ascertained by comparing the stand-
ard length of the fish with its total length.
As defined by Hubbs & Lagler (1947:13),
total length includes the caudal fin, where-
as standard length does not.
The relationship between growth of
body to growth of tail was calculated from
measurements of 264 warmouths taken
from Park Pond, summer, 1948, and No-
vember, 1949, and Venard Lake, October,
1949. As the average body length of the
warmouths increased, the average tail
length became relatively less, table 17. In
fish less than 4.0 inches total length, the
average total length was 1.259 times the
average standard length; in fish of 4.0 to
6.9 inches, the average total length was
1.240 times the average standard length;
and, in fish longer than 6.9 inches, the
average total length was 1.211 times the
average standard length.
Relation of Growth in Length to
Growth in Weight.—The relationship
between growth in length and growth in
weight was calculated from data on 866
warmouths collected from Park Pond be-
tween early June, 1948, and early No-
vember, 1949. Size groups were estab-
lished at 0.1-inch intervals. Average
weights were determined for each group
within the size range beginning with 3.3
and ending with 8.2 inches total length.
The length-weight relationship for each of
Table 17.—Factors derived from measurements of warmouths from Venard Lake, October,
1949, and Park Pond, summer, 1948, and November, 1949, for converting standard length (S.L.)
to total length (T.L.), and the reverse, with the same and with different units of measurement.
Tora. NuMBER
LENGTH, OF
IN Fi V40 5.1,
oe us (Same Units)
Under 4.0......... 130 0.795
AL OG ee eet te 93 0.806
OVveniG Oe oe 6 ten 41 0.826
Combined......... 264 0.809
ConvVeERSION Factors
Sh tor. S.L. (Mm.) T.L. (Inches)
(Sane Linits) to T.L. to S.L.
(Inches) (Mm.)
1.259 0.0495 20.18
1.240 0.0488 20.48
1.211 0.0477 20.98
1.240 0.0487 20.52
August, 1957
the specimens (866) was expressed by the
equation:
log W= -4.49867+3.04902 log L
where W+weight in grams
and L=standard length in millime-
ters
Length-weight relationships were calcu-
lated for the especially heavy and especially
light warmouths in the Park Pond popula-
tion. For warmouths heavier than aver-
age, the equation was as follows:
log W= -4.36191+3.01387 log L
For those lighter than average, the equa-
tion was as follows:
log W= -4.35603+2.95352 log L
From these equations, it may be seen that
fish either heavier in relation to length, or
lighter in relation to length, than the av-
erage bore a systematic relationship of
length to weight roughly paralleling that
of the average. Such divergence from the
average as was discernible was found par-
ticularly among the fish of greater lengths
and weights, fig. 16.
Coefficient of Condition
‘The coefficient of condition (C), based
on total length in inches and weight in
pounds, was computed for the 866 Park
Pond warmouths used in the analysis of
length-weight relationships. Fish smaller
than 3.3 inches total length were not con-
sidered because individuals were weighed
only to the nearest 0.01 pound, and greater
weighing preciseness would have been nec-
essary if smaller fish had been used; war-
mouths of more than 8.2 inches total
length were not used because few were
available.
Condition (C) increased progressively
with increased size of fish. The average
C (weighted to compensate for differences
in numbers of individuals in groups) for
each of several size groups, 3.34.2,
f3-9-2, 5.3-6.2, 6.3-7.2, and 7.3-8.2
inches total length, was 72.6, 74.8, 78.6,
80.9, and 82.6, respectively. Warmouths
within the size range 3.3—4.2 inches total
length showed a wide seasonal variation in
condition (C). This variation among
small warmouths may have been caused by
their dependence upon food items that fluc-
tuated widely in abundance from month to
month, such as cladocerans and certain in-
sects and their larvae. Larger warmouths,
Larimore: Lire History oF THE WARMOUTH 51
STANDARD LENGTH IN MILLIMETERS
50 100 150 200
0.80
350
— ALL FISH
O70: ae! FISH HEAVIER
THAN AVERAGE 300
—~- FISH LIGHTER
0.60 THAN AVERAGE
250
” 2p)
2 0.50 a
Z a
3 200. ©
z 0.40 =
z
= x
F 150 °
ig 0.30
: =
100
0.20 :
0.10 i
.
1.0 2.0 3.0 4.0 5.0 60 7.0 80 9.0 10.0
TOTAL LENGTH IN INCHES
0.00
Fig. 16.—Curves illustrating the relationship
between length and weight of warmouths col-
lected from Park Pond, early June, 1948,
through middle November, 1949.
feeding more upon crayfish and fish, varied
less in body condition from one season to
the next than did small warmouths.
The condition (C) of warmouths for
each of three size groups, 4.3—5.2, 5.3-6.2,
6.3—7.2 inches total length, was similar in
seasonal fluctuations. A sudden, severe
drop in condition occurred in September,
1948; a low level in condition lasted
through October, and was followed by a
rapid recovery by mid-November. Con-
dition declined gradually during the winter
and spring, but then began an increase that
continued through May and June. Condi-
tion remained relatively high and constant
throughout the summer of 1949 and then
declined during the fall months. Fig. 17
suggests that for the warmouths of Park
Pond a definite cycle of condition associ-
ated with seasons could not be established.
Since food habits were studied for these
warmouths collected from early October,
1948, to early November, 1949, it was pos-
sible to associate the foods eaten with the
seasonal variations in condition of the fish.
The low level of condition in the winter
(1948-49) was coincident with a compar-
atively low consumption of crayfish, dip-
aye Ittinois NaruraAL History SurveEY BULLETIN
teran larvae, amphipods, and mayfly
nymphs and with a comparatively high
consumption of fish and dragonfly nymphs,
fig. 6. During the spring of 1949, when
@
@
@
rs
@
°o
7.6
Z2
6.8
COEFFICIENT OF CONDITION
6.3'-7.2"
the warmouths used in the present study
are as follows:
1. There was a regular increase in the
number of annuli accompanying an in-
OCT NOV DEG JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV
1948
1949
Fig. 17—Coefficient of condition of 392 warmouths of three size groups (6.3-7.2 inches,
5.3-6.2 inches, 4.3-5.2 inches) collected from Park Pond, early October, 1948, through early
November, 1949. Warmouths collected and weighed in the summer of 1948 were so few in num-
ber that data on them were not included in the graph.
the warmouths were eating high percent-
ages of crayfish (volume) and damselfly
nymphs (frequency), the condition of these
fish was steadily improving. The rela-
tively good condition of warmouths during
the summer of 1949 was associated with
the extensive use of mayfly nymphs, cad-
disfly larvae, and crayfish.
There were no consistent differences in
condition between male and female war-
mouths in Park Pond.
Scale Method of Calculating Growth
The method of calculating warmouth
growth from fish lengths and scale meas-
urements is a composite of methods devel-
oped by several authors but generally fol-
lows the procedures suggested by Hile
(1941).
Validity of the Annulus as a Year-
Mark.—Age and growth studies made
from the scales of warmouths in Venard
Lake and Park Pond indicate that the an-
nulus is a reliable year-mark in this spe-
cies. Hile (1941:201-4) outlined the
most important features of a valid annu-
lus. Four points used to test the validity of
the scale method of age determination for
crease in size of fish, and fish assigned to
any single age group were within a cer-
tain length range, table 18.
2. Lengths calculated from scale meas-
urements agreed reasonably well with ac-
tual lengths of fish of corresponding ages,
tables 18 and 21.
3. Calculated lengths were similar for
the same age groups of fish collected in
different years and consistent for different
age groups of fish collected in the same or
different years. Because the calculated
lengths were very similar for warmouths
in the 1948 and 1949 Park Pond collec-
tions, data for these two collections were
Table 18.—Averages of total lengths of war-
mouths of various ages collected from Park
Pond, June, 1949.
AVERAGE
NuMBER Tora | RANGE oF
Year or Lire| oF Fish | LenoTu, Tora.
INCHES LENGTH
wey 17 230 1.9-2.8
Bt. 35 3.53 2.8-4.6
Ar, 90 5.20 3.6-7.1
Soe 114 6.62 5.48.2
6x, 31 7.66 6.0-8.7
Vol. 27, Art.14
ee ee
August, 1957
combined and are not shown separately ;
however, consistency in calculated lengths
of fish of the same and of different age
groups is shown in tables 21 and 26.
4. There was similarity among war-
mouths of different year classes with re-
spect to growth rates in certain calendar
years, tables 23 and 24.
Characteristics of the Annulus.—
The true annulus on the warmouth scale
appears as a result of resumption of
growth of body and scales after the cessa-
cae
ND ae. ey)
AN Ni We sy,
Larimore: Lire History oF THE WARMOUTH 53
tion of growth during winter months. True
annuli or year-marks usually show several
rather definite characteristics, fig. 18.
Across the anterior field of the scale the
annulus appears as a break in the arrange-
ment of circuli; it is bordered on the in-
side by closely spaced, incomplete circuli
and on the outside by complete, widely
spaced circuli. The radii in the anterior
field are slightly distorted in the region of
the annulus. On the lateral fields of the
scale, the annulus and newly formed circuli
Fig. 18—Warmouth scale: 4, wide spacing of circuli especially evident following resump-
tion of growth in spring; B, first annulus; C, second annulus; D, crowding of circuli during
period of slow growth resulting from habitat disturbance; £, new circuli cutting across ends
of circuli laid down in previous season.
54
“cut over’ the circuli laid down near the
end of the previous season. The annulus
extends only part way across the posterior
field of the scale. Slight differences in
spacing of circuli and in the lengths of
ctenii (small surface spines on scale) may
aid in recognizing the location of the year-
mark in the posterior field.
The first annulus formed on the war-
mouth scale does not show as much “‘cut-
ting over” in the lateral fields as do later
annuli, nor are the differences in spacing
of circuli so apparent in the first as in later
annuli. The differences which may exist
in length and distribution of ctenii are
most useful in recognizing the first an-
nulus. Annuli formed later are generally
more difficult to recognize with certainty,
mainly because they are closer together
than those earlier marks laid down when
the fish was increasing rapidly in length.
Time of Annulus Completion.—
In 1949, the time of annulus completion
in warmouths at Park Pond was deter-
mined from 129 specimens collected be-
tween April 7 and May 20. Sixty-eight
per cent of the warmouths collected May
13 and 14 had laid down the year’s annuli
on their scales, so that the average time of
annulus completion appeared to be about
the first week of May, table 19, at which
time the water temperature 1 foot below
the surface of the water was about 70 de-
grees F., fig. 9. Small fish usually lay
down the year-mark earlier in the spring
than do the larger ones, because the former
begin to grow at an earlier date. Fifteen
per cent of 39 fish collected from Park
Pond on April 7 and 9 showed new an-
nuli on their scales; all but one of these
fish were less than 4 inches total length.
As annulus formation is associated with
the resumption of growth of the fish in
spring, the annuli on the scales of fish may
not be completed at the same time each
year, and the time may vary from one pop-
ulation to another. Warmouths in Venard
Lake showed a period of annulus forma-
tion in 1949 that differed from the pe-
riod shown by the warmouths in Park
Pond. In the fish collected from Park
Pond, some year-marks appeared before
April 7, but only 68 per cent of the fish in
the May 13-14 collections had completed
annulus formation; the period in which
annuli were being completed covered more
Ittinors NatrurAL History SurvEY BULLETIN
Vol. 27, Art. 1
than 6 weeks. In Venard Lake, on the
other hand, none of the specimens col-
lected on April 5 had formed an annulus;
in the collection of May 12, about 5 weeks
later, 30 of 31 fish (nearly 97 per cent)
had completed annulus formation.
Ecological conditions in Venard Lake,
where warmouths were confined to a small
area having only minor fluctuations in
Table 19.—Percentages of warmouths with
and without new annuli, Park Pond collec-
tions, 1949.
a ee ee
PER- PeEr-
DaTE NuMBER | cENTAGE BA eee
OF OF LACKING ,
CoLLEcTION FisH heer bait:
ANNULI
April7-9....| 39 85 15
May 13-14...| 38 32 68
Mayr 16.56. 40 20 80
May 20..... if) 8 92
depth, probably were more nearly uniform
than in Park Pond, where warmouths
were found in shallow sloughs, deep chan-
nels, and open waters. It seems reasonable
to believe that a population inhabiting a
pond with a wide variety of physical con-
ditions might show annulus formation over
a longer period than a population exposed
to more nearly uniform physical conditions.
Furthermore, in Park Pond, fish of many
other species were competing with war-
mouths for the natural foods available in
early spring. ;
False Annuli.—Some scales of war-
mouths show false annuli, or marks which —
are not true year-marks but merely indica-
tions of physiological disturbances during
growing seasons. False marks were found
on the scales of many fish from Park Pond. —
Most of them could be recognized with
confidence. They did not appear uniformly
throughout a population or regularly at
definite times of year.
False marks were formed on the scales
of a large part of the warmouth population
of Venard Lake during August of 1948.
These marks could be distinguished, par-
ticularly in the 1947 year class, on the
scales of fish collected in succeeding years.
Since monthly collections allowed the false
annuli to be originally dated and to be |
recognized by their location in relation to |
August, 1957
true annuli on the scales in later collec-
tions, these marks gave little trouble in
age determinations. The formation of the
marks coincided with a 4-week period of
shoreline dredging with a dragline. Such
a severe disturbance of the habitat must
have reduced the food supply or its avail-
ability and caused a temporary stoppage
of growth that produced the false marks.
Growth in Park Pond
Park Pond, an 18-acre lake in a flooded
stripmine area, in 1948 and 1949 sup-
ported an old (60 years at least), rather
large fish population of about 36 species
native to the region. Most of these spe-
cies had been introduced into the lake from
the Salt Fork in times of flood, page 4.
Collection and Preparation of Ma-
terials.—In the period beginning June 7,
1948, and ending November 12, 1949,
1,420 warmouths were collected from Park
Pond. Hoop nets, fig. 19, were used in
collecting 367 warmouths; of these fish,
298 were collected between early June
and mid-September, 1948, and 69 between
LarimoreE: Lire History oF THE WARMOUTH 55
June 27 and July 5, 1949. An electric
shocker rigged for operation from a row-
boat (Larimore, Durham, & Bennett
1950) was used to collect specimens for
growth analyses and food studies. A total
of 788 fish were taken by this method in
collections made at monthly intervals from
early October, 1948, to early November,
1949, except that no collections were made
in February and October, 1949. Even
though Park Pond supported the largest
naturally established warmouth population
that had then been examined in Illinois,
warmouths were never taken there in great
numbers; a good day’s take might consist
of 2 dozen warmouths from the usual set
of six hoop nets or 50 warmouths from the
operation of the electric shocker. Large
specimens predominated in the hoop net
catches; fish of all sizes were present in
collections made by shocking. On August
22, 1949, rotenone was applied to a shal-
low, isolated, 0.47-acre slough in Park
Pond, and a census was made of the fish
population. Scales for growth studies
were taken from 265 of the 504 war-
mouths collected from this area.
Fig. 19.—Collecting fish with a hoop net in Park Pond.
56
Ages were determined for 1,328 of the
1,420 warmouths collected (265 from the
shallow, isolated slough and 1,063 from
other parts of Park Pond). Scales from
84 fish were regenerated and unreadable;
scales of 8 other specimens were so difficult
to read that ages could not be determined
with certainty. Fish from the slough that
was treated with rotenone were considered
separately because they showed growth
rates significantly different from those.
taken in the other collections. Impressions
of the warmouth scales were made on cellu-
lose acetate slides, and the images of these
impressions were projected for study at a
magnification of 41 diameters. Measure-
ments along the median, anterior radius of
a magnified scale image were marked on
a manila paper strip, and the strip was
used for calculating past growth on a
nomograph, as described by Carlander &
Smith (1944). Calculated lengths, based
on a straight-line relation between scale
length and body length, were corrected for
an intercept of 0.53 inch in body length
(fig. 15 and equation on page 50).
The following sections, “Growth Dif-
ferences Between Sexes,’ “History of
Successive Year Classes,” ‘‘Fluctuations
in Annual Growth,” and ‘Seasonal
Growth,” refer to Park Pond warmouths
other than those from the slough.
Growth Differences Between
Sexes.—Sex was determined by dissection
or by visible discharge of sex products for
I_ttino1is NATURAL History SuRVEY BULLETIN
600 specimens in year classes 1944 through
Vol. 27, Art. 1
1948. Calculated lengths of males and fe- —
males of each of the year classes were aver-
aged and compared, table 20. Fish in both
the 1943 and 1949 year classes were rep-
resented by so few specimens for which
sex was determined that they were omit-
ted from the calculations.
Very consistent, although rather small,
differences existed between the growth
rates of males and females.
larger than females at the end of each year
of life in the five year classes considered.
The greatest differences occurred in the
1944 year class, but the small number of
specimens (only seven females) made this
growth comparison less reliable than that
for other year classes. The next oldest
brood, the 1945 year class, was represented
Se
Males were —
ee
a
by 187 specimens. Males in this group av- —
eraged only a little longer than females. —
Schoffman (1940:32) observed that the
¥
lengths and weights of male and female —
warmouths of the same ages in Reelfoot |
Lake, Tennessee, were either the same or_
only slightly different.
Since the actual differences in lengths —
of male and female warmouths were rather
small in those year classes represented by
substantial numbers of specimens, data for —
the two sexes were not separated in the
growth analyses discussed in the following
paragraphs.
History of Successive Year Classes. —
—All the specimens were assigned to year
Table 20.—Average calculated total lengths in inches for male and female warmouths, ~
representing five year classes, collected from Park Pond, October, 1948, through November, 1949. —
AVERAGE CALCULATED Tota, LENGTH IN INCHES AT END OF
InpIcATED YEAR OF LIFE
Ciae NuMBER
Crags SEx OF
; FisH
1
1944..... Male 15 1.64
Female 7 1.46
1945. Male 102 1/3
Female 85 1.62
1946.. Male 84 1.56
Female 85 1.56
1947.. Male 79 1.58
Female 7A 1.48
1948. Male 33 1.62
Female 39 1.61
2 3 4 5
3.31 3.39 6.68 oe
SxOl 4.72 Soo 6.35
3.49 4.89 5.88
3.34 4.68 5.85
2.85 4.21
2.81 4.11
2.99
2.61
August, 1957
LarimoreE: Lire History oF THE WARMOUTH
at
Table 21.—Average calculated total lengths in inches for 1,063 warmouths, representing
nine year classes, collected from Park Pond, June, 1948, through November, 1949.
AVERAGE CALCULATED Total LENGTH IN INCHES aT END oF INDICATED
YEAR OF Lire*
NuMBER
YeArR Crass OF
FisH
1 2 3
RO40 4.5. 62. 1 1.61 3.08 4.20
24S 6 1.58 2.86 4.39
7 ae 10 1.47 2.89 4.54
MA Sia sls 46 1.59 Bo DS 5.28
HOAA ee. 12D 1.62 STi Sets:
“Ci aa 362 75 3.80 4.86
META GA fathom ocr 239 1.59 2.90 4.26
BA ot 187 £55 2285
EES Se ee 90 1.63
Weighted
MBPT Ces ree Js 2. | L.0F 3.38 4.91
4 5 OH4e 7 8
5.807 | 6.33921? 6938) 7.94. |, S161
Coca ee ae Ne a ae en
508. 7.57 pn 8 Oe | 8.44
7.00 | 7.69 | 8.76
6.75 | 7.10
5.99
6.40 | 7.44 | 8.02 | 8.47 | 8.56
*Average for last year in each year class based on fish in which annulus for current year was present.
classes on the basis of number of true an-
nuli on their scales. The length of each
fish at the end of each year of life was cal-
culated from its scale measurements. The
calculated lengths for each year of life
were then averaged for fish of each year
class. In the length calculations for 1948
growth of fish collected in 1949, only those
fish taken after annulus formation in May
could be used. The calculated lengths for
1,063 warmouths, table 21, suggested the
following conclusions:
1. Average calculated lengths for fish
of the 1943, 1944, and 1945 year classes
were greater in most years of life than the
weighted averages for the fish of all year
classes (averages were weighted to com-
pensate for differences in numbers of fish in
the various groups) ; fish of both the 1944
and 1945 year classes showed less than the
average length for the last complete grow-
ing season (1948) prior to capture.
2. Average calculated lengths for fish
of the 1946 and 1947 year classes were less
in most years of life than the weighted ay-
erages for the fish of all year classes.
3. Average calculated lengths exhib-
ited no large growth rate differences for
the same years of life among warmouths
caught at different ages—no phenomenon
of apparent change in growth rates as de-
scribed by Lee (1912:9). (However.
Table 22.—Average calculated total lengths in inches for each year of life of 1,063 war-
mouths collected from Park Pond, June, 1948—November, 1949, with equivalent standard lengths
in millimeters and weights in pounds and grams. Calculated annual increments in lengths and
weights are based on these averages.
ANNUAL
| CALCULATED Cc ANNUAL
Tora. STANDARD - | Increment | ~AUCULATED
: WEIGHT, WEIGHT INCREMENT
Year or Lire LENGTH LENGTH, x 2 or ToraL =
> : Pounpbs Grams = or WEIGHT
INCHES INCHES LeNcTH, Pacis”
INCHES es
BES 1.64 33 0.004 1.8 1.64 0.004
Z... 3.38 68 0.026 11.8 1.74 0.022
Bi... 4.91 101 0.088 39-9 B53 0.062
aa... 6.40 131 0.200 90.7 1.49 0.112
ee. 7.44 153 0.337 152.9 1.04 0.137
6... 8.02 168 0.432 196.0 0.58 0.095
i. 8.47 178 0.510 231.3 0.45 | 0.078
By. 8.56 180 C2521 239.0 0.09 | 0.017
WEIGHT INCREMENT IN POUNDS
58 Ittrnois NaTturAL History SurvEY BULLETIN Vol. 27, Art. 1
10.0 20
0.15
0.60 o
Fs}
es 215
w” n”
¢ S =
z 60 LENGTH 0.408 E 0.10
z — Sie WEIGHT /
Ge Ey = /
& 40 WEIGHT = 3 }
za o =
WwW
wy ae LENGTH 0.05
- YU.
20 2
=
00
| Ee Name bei > ag Gia =
AGE IN YEARS
Fig. 20.—Averages of calculated total lengths
and calculated weights at end of each year of
life for 1,063 warmouths of various ages from
Park Pond, early June, 1948, through middle
November, 1949.
Lee’s phenomenon was evident in Venard
Lake warmouths, figs. 23 and 24.)
Annual length increments based on cal-
culated lengths were determined for each
year of life of the 1,063 warmouths, table
22. These length increments were greatest
for the second year of life and decreased
thereafter; they declined rapidly after the
fourth year and were very slight in the
eighth year of life.
The pattern of weight increase was dif-
ferent from that of length increase. Aver-
age calculated weights in pounds, corre-
sponding to average calculated lengths in
inches (length-weight prediction equation,
page 51), furnish evidence that in the war-
mouths studied the rate of weight in-
crease was slow during the first 2 years,
| 2 3. 4 5 56ers
YEAR OF LIFE
Fig. 21.—Averages of annual increments of
calculated total lengths and calculated weights
in each year of life for 1,063 warmouths from
Park Pond, early June, 1948, through middle ~
November, 1949.
reached a peak the fifth year, and declined
rapidly in the following years, table 22.
Fig. 20 shows the average lengths and
weights; fig. 21 shows the increments of —
length and weight for each year of life.
Fluctuations in Annual Growth.—
There were calendar years of good and of —
poor growth for all year classes of war-
mouths at Park Pond. These years of good
and of poor growth were evident even
though warmouths in certain year classes
were of consistently larger or smaller sizes —
than the average for all warmouths.
Using the average annual length incre- —
ment for all warmouths in each year of ©
life as a base, tables 21 and 22, one can cal- —
culate the percentage of the expected in- —
crement attained by each year class for
Table 23—Average percentage of expected annual length increment attained in each year
of life in eight separate year classes of 1,062 warmouths collected from Park Pond, June,
1948—-November, 1949.
NuMBER
YEAR CLass OF
Fis
1 2
BOA Tee ey. 6 96 74
GY 9 Gea en 10 OO n2e| 82
194s ee ti So 46 o7 mI 95
1 hey: © eae ae 122 99 124
| Pe a) ee Saas LOJE Me AS
IGAGICES ot =| 239 | 97 75
jf 9 sae aa 187 ote | 75
Oy te ee ae 90 | 99 |
AVERAGE PERCENTAGE OF ExpecreD ANNUAL LENGTH INCREMENT
ATTAINED IN INDICATED YEAR OF LIFE
3 4 5 6 ¥
100 91 110 176 149
108 97 134 116
133 115 66
128 68 34
69 76
88
|
j
j
}
:
:
:
August, 1957
each year of life and for each calendar year,
table 23. Percentages of expected growth
during selected calendar years may be read
from table 23 in diagonal rows from lower
left to upper right. The percentages of ex-
pected growth in each calendar year, when
averaged, show clearly the fluctuations in
annual growth, table 24.
Actual length increments exceeded the
expected increments in only 1945 and
1946, table 24. Poor growth in 1942 and
1943 may have been due to heavy floods,
which caused the water to remain muddy
for 6 or 7 weeks during the early summer
of each of these years.
The exceptionally good growth of war-
mouths during 1945 and 1946 may have re-
sulted from an artificial thinning of the
fish population. On June 26, 1945, May
15, 1946, and July 29, 1946, Dr. George
W. Bennett and other members of the I]li-
nois Natural History Survey staff sprayed
most of the shallow waters of Park Pond
with rotenone to reduce the numbers of
small fish in the population. Although no
estimate could be made of the percentage of
the total fish population killed by these par-
tial poisoning operations, the great num-
ber of small fish destroyed may well have
allowed a substantial increase in growth
rates of the surviving fish.
Seasonal Growth.—Growth patterns
of the 1946, 1947, and 1948 year classes
of warmouths in Park Pond during the
summer of 1949 are shown in fig. 22. The
length increment for each fish was calcu-
lated from scales. The growth increment
on each scale used was measured on the
Table 24.—Average percentages of expected
annual length increment attained in each cal-
endar year by warmouths collected from Park
Pond, June, 1948—November, 1949; year classes
combined.
AVERAGE PERCENTAGE OF
Be cons - Numser |ExpecreD ANNUAL LENGTH
wee Vea OF INCREMENT ATTAINED
Fisu In Eacu YEAR OF LIFE
nO41..... 6 96
1942... 16 82
n943).... 62 93
1944. 194 98
1945.. 546 114
1946. 785 128
1947... 972 91
1948... 526 74
Larimore: Lire History oF THE WARMOUTH 59
1948 YEAR CLASS
1.0 1947 YEAR CLASS
1946 YEAR CLASS
INCREASE IN LENGTH FOR 1949 SEASON (INCHES)
(e)
no
MAY JUN JUL AUG SEP OCT NOV
Fig. 22.—Averages of length increases of
warmouths of the 1946, 1947, and 1948 year
classes in Park Pond during the 1949 growing
season. The growth increment for each war-
mouth was calculated from scale growth out-
side of the last annulus.
median anterior radius from the outermost
annulus to the margin of the scale. Aver-
age monthly length increments were calcu-
lated from scale collections made each
month except October in a period that be-
gan in May and extended into November.
When more than one collection was made
in a single month, the collections were
combined and an average date was used.
In this particular analysis, year classes
other than those of 1946-1948 could not
be used because they were not represented
by sufficient numbers of warmouths to give
validity to the calculations.
Growth was rapid for the three year
classes in May and June, and this good
growth continued through July for the
1948 year class, fig. 22. Growth rates de-
creased in July for the 1946 and 1947
year classes and improved considerably in
August. Little or no growth was evident
in the three year classes after August. Cer-
tain general differences were discernible
between the fish of these year classes. The
oldest fish (1946 year class) showed a mid-
summer slump in growth and had com-
pleted their seasonal growth by September,
whereas the youngest fish (1948 year class)
60
grew rapidly through July and showed
some growth in each of the months through
October. The growth pattern for the 1947
year class was intermediate between the
patterns for the 1946 and 1948 year classes.
Seasonal growth rates of three year
classes of warmouths in Venard Lake are
shown in figs. 23 and 24.
Measurements of warmouths from Park
Pond, fig. 22, from Venard Lake, figs. 23
Ittinois NATuRAL History SuRVEY BULLETIN
Vol. 27, Art. 1
long. Most of these warmouths were less
than 3.5 inches in length.
Age determinations for 265 of the 504
warmouths revealed a growth rate consid-
erably less than was found in other areas
of Park Pond, table 25. Of the 265 speci-
mens aged, very good growth was found in
23 large fish belonging to the 1944 and
1945 year classes. These fish did not seem
to be representative of the population of
Table 25.—Average of calculated lengths of 265 warmouths from which scale samples
were taken, after being collected from Park Pond Slough, shown with similar calculated lengths
of warmouths from other parts of Park Pond.
e Ca.cuLatep Tora LenctH at Enp or AVERAGE
YEAR NuMBER INDICATED YEAR OF LIFE Tora.
Group oF FiIsH Ces OF LENGTH
FisH AT
2 3 = 5 CapTURE
Fast-growing
warmouths from 1944 2 1.74 4.07 5.38 6.65 Ta TESS
slough 1945 21 1.91 3.83 5.14 5.87 6.15
Slow-growing 1945 10 1.56 2.90 4.00 4.86 5,27
warmouths from 1946 74 1.54 2.85 3.97 4.59
slough 1947 93 1.46 2.54 3.34
1948 52 1.48 2.50
1949 13 1.65
Slow-growing
warmouths from 242 1.50 2.64 3.64 4.62
slough, average
Warmouths from Combined
other Park Pond year
areas, average classes 1,063 1.64 3.38 4.91 6.40
and 24, and from certain Oklahoma wa-
ters (Jenkins, Elkin, & Finnell 1955 :42)
indicated an apparent decrease in the aver-
age lengths of the fish of some age groups
in July or August. This apparent decrease
may have been due to changes in habits or
distribution of the warmouths from the
early part to the middle part of the sum-
mer, changes which might have affected
the efficiency or selectivity of the collecting
method, with a result that a proportionally
smaller number of large members in each
age group was taken.
Growth in Localized Population.
—In the isolated, 0.47-acre Park Pond
slough to which rotenone was applied in
1949, warmouths comprised 10.4 per cent
of the weight of the fish population. Al-
though this weight represented 504 indi-
viduals, only 18 were more than 6 inches
the slough. Their history of rapid growth
suggested they had only recently moved
into this area.
ee eee eee
All of the smaller specimens in this —
slough showed consistently poorer growth
than warmouths from other areas of Park
Pond. A study of the fish population of
the slough indicated that (1) isolated pop- —
ulations of warmouths existed within the
total warmouth population of Park Pond;
(2) individuals of these isolated popula-
tions, most of them in dense weed beds, ©
grew slowly; and (3) individuals of these
populations appeared to remain in the same —
locations throughout their life spans.
Compensatory Growth.—Three hun- —
dred thirteen warmouths from Park Pond ~
were separated into three size groups based —
on calculated lengths of fish at the end of |
the first year of life, table 26. The average
August, 1957
length increment for each year of life was
then calculated for each size group as a
means of determining the growth rate—
whether fast, intermediate, or slow.
Of the 313 warmouths considered, 94
had been collected with hoop nets during
the summer of 1948; these 94 were fish of
the 1944 year class and were faster-grow-
ing individuals than the specimens (219)
that had been taken from the slough. War-
mouths taken from the slough had been
collected after being poisoned with rote-
none; they belonged to the 1946, 1947,
and 1948 year classes, table 26.
For the fish taken in hoop nets, the
difference in average calculated lengths be-
tween the largest and smallest size groups
was 0).55 inch for the first year of life, 0.74
inch for the second, 0.55 inch for the third,
and 0.42 inch for the fourth. The decline
in differences between these two size
groups in the third and fourth years of life
may indicate compensatory growth among
LarimorE: Lire History oF THE WARMOUTH
61
individuals of the smallest group in these
years. However, the compensatory growth
that occurred was slight and it did not
overcome the length advantage held by the
fish that grew most rapidly during the first
year of life.
In the slow-growing population from
the slough, the maximum differences in
length between the two extreme size
groups of the various year classes declined
little or not at all after the second year. In
the 1946 year class, after an increase in
length difference at the end of the second
year, the differences were about the same
at the end of the third and fourth growing
seasons, table 26.
A study of compensatory growth in
these four year classes of warmouths from
Park Pond suggested the following con-
clusions:
1. Warmouths that were largest at the
end of the first year of life increased this
length advantage in the second year of life.
Table 26—Compensatory growth, in inches, in four year classes of warmouths collected
from Park Pond. Fish in the 1944 year class were collected in hoop nets from several parts of
Park Pond in the summer of 1948; those in 1946-1948 year classes were taken from a slough
to which poison was applied on August 22, 1949.
CALCULATED AVERAGE | CALCULATED AVERAGE
Year Chass Group or Fisu, Basep Tora LenctuH at Enp | Lencru INCREMENT IN
hp PiAce | o™ CarcutateD Toran | NumBer | or Inpicatep YEAR OF | INDICATED YEAR OF
s LencTH IN INCHES AT OF Lire pices
ae Enp or First YEAR OF Fisu
Lire
1 2) 3 4 1 2 3 4
Below 1.45 wp MSS SeIouOMOS lon OMLese 22 Oei rel sm ten ae
1944 1.45-1.70 42 1.58 13.80) 15.74 16.76 1.58 2.22 |1.94 9/1 02
(Entire pond) {Over 1.70 30 1.88 |4.27 |6.23 |7.12 |1.88 |2.39 |1.96 |0.89
Maximum difference OPS 7429 OM SIS ia OAD Ie te toe |e Dee | eee
1946 Below 1.3 13 LeQONDE 49) Br Ol 4255120) MDOT OM) OnG4
(Slough) 1.3-1.6 33 143) 12263 18.74) |42354|0 43a 20) 11) On6l
Over 1.6 28 1.84 |3.28 |4.41 |5.047]1.84 |1.44 11.13 |0.63*
Maximum difference 0.64 |0.79 10.80 |0.79
Below 1.3 19 22 224 1S) Ae PU SPN OPES KO) Stoel en a!
1947 1.3-1.6 55 NA ee 2A | Seiie Stal OG a ORs Orne
(Slough) Over 1.6 19 Lee SOS |Sia7i9e a lliestekle WV BOD TKO). HAS. ye 2
Maximum difference 0.59 |0.79 10.68
Below 1.3 14 1.24 |2.24* 1.24 |1.00*
. 1948 1.3-1.6 24 1.41 |2.42* 1.41 1.01*
(Slough) Over 1.6 14 1.82 |2.89*}. 182 Ore
Maximum difference 0.58 |0.65
*Empirical length representing growth to August 22, 1949.
62 Intinors NATURAL History SuRVEY BULLETIN
2. Warmouths that were smallest at the
end of the first year of life showed no com-
pensatory growth in the second year but
showed a slight compensatory growth in
the third year.
3. Although warmouths that grew fast
the first year of life underwent a decline
in annual length increment after the sec-
ond growing season, they retained their
length advantage over warmouths that
grew slowly the first year.
4. Warmouths that grew slowly the
first year of life showed more compensa-
tory growth in later years if they were
members of fast-growing populations than
if they were members of slow-growing
populations.
These conclusions are in fair agreement
with those from similar studies done on
several other sunfishes. Hubbs & Coop-
er (1935:678) found no compensatory
growth during the second year of life in
the longear sunfish, pumpkinseed, or blue-
gill, or in bluegill pumpkinseed hybrids.
Their data did not include growth rates
beyond the second year. For the rock bass,
Hile (1941:332) stated: “First-year ad-
vantage in size may be retained over | or
2 additional years, but more probably it
will be increased in the second and/or
third year of life. Compensatory growth
occurs in the later years.”
Sizes and Longevity.—A 9.6-inch
male was the largest warmouth collected
from Park Pond. This fish weighed 1.0
pound and was 6 years of age. The ma-
jority of the large fish were males. Al-
though the males grew slightly faster than
the females, table 20, it did not necessarily
follow that the males reached greater max-
imum sizes than did the females. The oc-
currence of more large males than large
females in the collections may have indi-
cated only that the former were more read-
ily taken than were the latter—a logical
hypothesis in view of the differences in be-
havior during the nesting season. ‘The sed-
entary nest-guarding habits of the males
would have made them very vulnerable to
collection by shocking.
Schoffman (1940:36) mentioned spawn-
ing habits to explain the greater percentage
of females than males in the groups of
large warmouths he collected from Reel-
foot Lake, Tennessee. As his collections
were taken with traps operated during the
Vol. 27, Art. 1]
breeding season, nest-guarding males were
not caught so readily as females. The larg-
est warmouth handled by Schoffman
(1940:34) was a 9.29-inch female.
Growth in Venard Lake
In 1948 and 1949, warmouths in Ven-
ard Lake, an artificial lake of 3.2 acres,
were associated with only one other species, —
the largemouth bass. Both species had —
been introduced in April, 1947, page 5. |
The 1,102 Venard Lake fish used in
this study were from collections made
with an electric shocker each month (ex-
cept January and February) in a period —
beginning September, 1948, and ending
October, 1949. Methods used for scale
preparation and age determination were —
similar to those described for the collec-
tions from Park Pond.
Since Venard was a recently stocked —
lake, it contained only a small number of ~
year classes of warmouths: 1947, 1948, —
and 1949. A comparison of growth rates —
was made between warmouths of the first, —
fast-growing year class (1947) and those —
of the two following year classes (1948
and 1949). The following points seem ap- —
parent, figs. 23 and 24:
1. Both actual and calculated lengths
of warmouths of the first year class to be
spawned in the lake (1947) averaged more
at the end of the first year and of each suc-
ceeding year of life than did those of later —
year classes.
2. The actual length range for mem-
bers of the first year class was greater than
that for members of each succeeding year —
class.
3. The average calculated lengths of
warmouths of 1947 and 1948 year classes
collected in successive months of 1949
showed a decline.
4, The average annual growth of war-
mouths in Venard Lake was very similar
to that of warmouths in their first 3 years
of life in Park Pond, table 27, in spite of
large ecological differences in the two habi-
tats.
Growth in Other Water Areas
The rate of growth of warmouths may
be influenced by various environmental fac-
tors or combinations of them. This fact is
August, 1957
illustrated by the differences observed in
the growth rates of warmouths taken from
12 Illinois water areas, table 27.
_ The most rapid growth recorded in I[1hi-
‘“nois warmouths was in Enright Pond in
~McLean County in which some members
of the first brood produced in the lake at-
tained 6 inches in total length during their
first 13 months. Thinning the total fish
LarIMoRE: Lire History oF THE WARMOUTH 63
population by intensive angling resulted in
an increase in the growth rate of war-
mouths in Onized Lake, a 2-acre body of
water in central Illinois (Bennett 1945:
396-7).
Exceptionally rapid growth of war-
mouths usually accompanies the expansion
of fish populations in new reservoirs. Dur-
ing the first 6 years after impoundment of
7.0
] RANGE OF ACTUAL LENGTHS
— AVERAGE OF ACTUAL LENGTHS
6.0
5.0
op)
LJ
a@
O
Z 4.0
TOTAL LENGTH,
er)
.e)
2.0
_ AVERAGE OF CGALCULATED LENGTHS
AT FIRST ANNULUS
AVERAGE OF GALCULATED LENGTHS
AT SECOND ANNULUS
SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT
1948
1949
Fig. 23.—Averages of actual total lengths and averages of calculated total lengths at
time of formation of first annulus and at time of formation of second annulus for warmouths
of the 1947 year class taken in 12 collections from Venard Lake, late September, 1948, through
middle October, 1949; also range of actual total lengths in each collection.
64 Ittinors NATURAL History SuRVEY BULLETIN
5.0
Vol..27, ATi
RANGE OF ACTUAL LENGTHS
AVERAGE OF CALCULATED LENGTHS
AT FIRST ANNULUS
a
oO
INCHES
TOTAL LENGTH,
—— AVERAGE OF ACTUAL LENGTHS
1948 YEAR CLASS
1949 YEAR CLASS
SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT —
1948
1949
Fig. 24.—Averages of actual total lengths and averages of calculated total lengths at time
of formation of first annulus for warmouths of the 1948 year class taken in 10 collections from
Venard Lake, early October, 1948, through middle October, 1949;
averages of actual total
lengths of warmouths of the 1949 year class taken in 4 collections, late June through late
October, 1949; also range of actual total lengths in each collection.
Lake Glendale, an 82-acre lake in Pope
County, Illinois, warmouths showed a
growth rate that was exceptionally fast for
the species (Dr. Donald F. Hansen of the
Illinois Natural History Survey, unpub-
lished studies of Lake Glendale). Another
example of improved growth rate in a new
impoundment is given by Hall & Jenkins
(1953:34) ; they found that, in Tenkiller
Reservoir in Oklahoma, the growth rate of
warmouths was rapid during the first year
of impoundment. Jenkins (1953:79)
found that in Grand Lake, Oklahoma, the
growth rate of warmouths gradually de-
clined during the years of impoundment.
Data from several studies of warmouth
growth in other states are summarized by
Carlander (1950:191-2; 1953:370-1).
An inspection of these data and those given
in table 27 reveals a wide range of differ-
ences in warmouth growth rates.
PARASITISM
No attempt will be made here to survey
all published records concerning parasites
of the warmouth. Reference should be
be made, however, to several important
studies involving autopsies of compara-
tively large numbers of warmouths. Holl
(1932:99-100) examined 90 warmouths
from North Carolina and discovered an in-
August, 1957
teresting seasonal fluctuation in relative
numbers of parasites and in percentages of
fish infested. In a study of centrarchids
from southern Florida, Bangham (1939:
265) examined 143 warmouths and found
all of them infested with parasites of one
Larimore: Lire History oF THE WARMOUTH 65
the genus Physa, any one of several spe-
cies of fish, and the great blue heron, drdes
herodias L. As little age immunity has
been demonstrated in intermediate hosts
of most flukes, the numbers of metacer-
cariae of this strigeid probably continue
Table 27.—Growth rates of warmouths in 13 water areas in Illinois.
: CatcuLaTeD Toray Lencru ar END oF
YEAR NuMBER InpicATED YEAR OF LIFE
Water AREA County OF OF
Co.ttection| FisH
1 2 3 + 5 6 a
Park Pond.........|Vermilion 1948-49 1,063). (0256. | 324: 4.9 [6.4 AA BLO 825
Park Pond Slough. .|Vermilion 1949 242 Wash | PP sion TZ8.6
Venard Lake......./McLean 1948-49 334) 127), 322 46
Woized Lake*...... Madison 1941 101 1.4 | 4.0 | 6.1
Lake Glendale... .. .|Pope 1945-46 10S, QFE 4 GG. 2
Mississippi Rivery.. . 1944 260 LS A408 es eral
Lake Chautauqua...|Macon 1947 SOim ANE 22/5 Ps 5) eS SeGns
40-and-8 Lake......|Henry 1954 D2. Ne deed. all eed Nae Ge Ould. 0
Staunton Lake..... Macoupin 1953 Eafe esha ihe M A5RG at Si
Mount Clare Lake. . |Macoupin 1953 Ge | LSE a AR Gwe 5he/
McKenzie Lake..... Montgomery | 1952 12. LB Dae) Sree eA ES a Ome) 4:
Weldon Springs...../De Witt 1952 yee ON Nie or |. Sp
Fairmount Quarries. |Vermilion 1953 NO TE Se Oo) 4h SE
*From Bennect 1945 :397.
7From Upper Mississippi River Conservation Committee
or more species. The fish populations from
which these specimens were taken con-
tained relatively high concentrations of
warmouths. Venard (1941:15) found
that of 45 warmouths examined from
Reelfoot Lake, Tennessee, all were para-
sitized. Bangham & Venard (1942:33)
listed 22 species of parasites from 58 speci-
mens examined from Reelfoot Lake; all
of the specimens were infested with para-
sites.
A comprehensive investigation of war-
mouth parasites was not made in this
study. The following brief discussions are
of the general relationships between the
hosts and four common parasites of war-
mouths from Venard Lake and Park
Pond.*
The strigeid fluke, Posthodiplostomum
minimum (MacCallum), was the most
abundant parasite of the warmouths in
Park Pond. Its hosts include a snail of
*Dr. L. J. Thomas, University of Illinois, checked the
identification of the cestode and trematode parasites and
suggested possible relationships between these parasitic
worms and the fish population. The late Dr. H. J. Van
Cleave, University of Illinois, identified the acanthocepha-
lan; Professor R. V. Bangham, College of Wooster, iden-
tified the nematode; and Professor M. C. Meyer, Uni-
versity of Maine, identified the leech.
1946:20.
to increase in the host warmouth until the
fish dies. Extremely heavy infestations of
metacercariae were found commonly in
Park Pond warmouths over 5 inches in
length, but seldom in smaller ones.
The bass tapeworm, Proteocephalus am-
bloplites (Leidy), was present in all war-
mouths examined from Park Pond. As a
plerocercoid larva, it occurred in most of
the internal organs, especially in the liver,
gonads, and mesenteries. Since the war-
mouths acquired these parasites by eating
copepods containing the procercoids, the
rate at which the fish acquired the para-
sites declined as the fish changed their food
preferences from Entomostraca to larger
items. Therefore, unlike Posthodiplosto-
mum, plerocercoids did not occur in rela-
tively greater numbers among the large
warmouths than among the small ones at
Park Pond.
An interesting nematode, Camallanus
oxycephalus Ward & Magath, lives in the
lower intestine of the warmouth. Blood-
red worms of this species were so numer-
ous in some warmouths from Park Pond
that they often formed tangled masses in
the lumens of the guts. Frequently Cammal-
66 Intinors NATuRAL History SurvEY BULLETIN
lanus worms were seen hanging as a red
tuft from the anus of a fish taken from the
water. Camallanus attaches to the inner
intestinal wall. The warmouth serves as
the final host, and infestation may take
place at any time.
The only parasite which infested no-
ticeable numbers of warmouths from Ven-
ard Lake was a leech, I/linobdella moorei
Meyer. During the autumn and winter of
1948, leeches of this species were present
in such large numbers that they appeared
as compact fringes on the fins of the war-
mouths. The caudal fins of the fish were
severely damaged, frequently suffering ex-
tensive destruction of the rays. Although
the infestation was still heavy during the
spring of 1949, only relatively few of the
leeches were seen during the following
summer months.
An examination of 25 ovaries from war-
mouths taken from Park Pond on No-
vember 12, 1949, revealed the following:
(1) 14 ovaries contained one or more par-
asites; (2) ovaries of all sexually mature
females were parasitized; (3) 24 plero-
cercoids of Proteocephalus ambloplites oc-
curred in 12 ovaries, as many as 4 in 1
ovary; (4) 27 metacercariae of Posthodip-
lostomum minimum occurred in 10 ova-
ries, 12 in 1 ovary; and (5) 4 sexually
undeveloped adult acanthocephalans, Lep-
torhynchoides thecatus (Linton), were
found in 4 ovaries (1 in each ovary). In
spite of these parasites, no sterile fish
were found and no primary damage to
the ovaries was evident.
Warmouths were collected in sufficient
numbers from Venard Lake and Park
Pond to permit tentative conclusions to be
drawn relative to the influence of para-
sites on the general physical condition of
these fish. Warmouths from Venard Lake
had fewer internal parasites and a consist-
ently higher coefficient of condition (C)
than had warmouths of similar sizes taken
from Park Pond. At the same time, among
the heavily infested warmouths of Park
Pond, no positive relationship could be
shown between a fish’s coefficient of con-
dition and the number of parasites present.
Therefore, it is believed that the difference
in condition of warmouths from the two
lakes was more directly a result of differ-
ence in densities of the total fish popula-
tions than of parasitism.
Vol. 27, Art. 1
Even though no harmful effects of para-
sites on the condition (C) of warmouths
in Venard Lake or Park Pond could be
demonstrated, possibilities of some other
harmful effects must be recognized. Fe-
male warmouths from Park Pond pro-
duced much smaller numbers of eggs than
did Venard Lake females, table 16, which
were less heavily infested.
BEHAVIOR
Observations on the behavior of the
warmouth are scattered through many sec-
tions of this publication. For example, the
aggressive behavior of the nesting male is
described (page 43) under “Spawning” in
the section on reproduction. It seems de-
sirable to bring together here certain as-
pects of observed behavior of the war-
mouth, although to do so will mean some
repetition.
General Activity and Disposition
The warmouth has a quiet disposition;
it moves around relatively little and dis-
plays no showy activity except during the
nesting season. It seeks the cover of weed
masses, stumps, or rocky banks (pages 6
and 8), and avoids intense light.
Reproductive Behavior
Tinbergen (1953:23) describes syn-
chronization, persuasion, orientation, and
reproductive isolation as functions of mat-
ing behavior in animals. These functions,
along with defense of the nest area, the
spawning act, and parental care, are con-
sidered here as reproductive behavior in the
warmouth.
Defense of the Nest Area.—The
nesting warmouth male displays an aggres-
sive threat toward other fish that approach
his nest area (page 42). He assumes a bel-
ligerent attitude by swimming toward the
intruder with his mouth open and his
opercles spread ; at the same time, his eyes
become red and his body becomes light yel-
low in color. As the nesting male nears
the intruder, he usually turns abruptly to
one side or upward and, with vigorous
movements of his tail fin, forces small
pulses of water toward the intruder. He
may also nip the intruder. The entire
|
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August, 1957
threat attitude associated with defense of
the nest area is similar to the persuasive
behavior employed by the nesting male in
courting a female (page 43).
Synchronization.— The spawning pe-
riod for warmouths extends over several
months (page 43). Male warmouths be-
come ready to spawn earlier and remain
capable of spawning later in the season
than do females. Thus, a ripening female
generally encounters many males ready to
spawn. More precise synchronization for
the actual discharge of sex products is
brought about by the preliminary court-
ship and persuasive gestures of the male
and finally by the thump given the male
as the female extrudes a group of eggs
(page 44).
Orientation.—The special orientation
for mating in warmouths consists simply
of the male having an established nest, the
female with ripening eggs wandering into
the vicinity of the nest, and the male initi-
ating the persuasive actions. A signal—
such as sound, odor, or color display, used
by many animals to attract a mate from
considerable distances—is not known to
be given by the male warmouth. However,
the female probably receives some internal
physiological stimulus to wander as her
eggs ripen and they become free for dis-
charge.
Persuasion.—The male warmouth’s
threat attitude, described above, serves to
initiate the action for persuading the fe-
male to spawn. A female that is not ready
to spawn responds to the threat as any
other intruder would and is driven from
the nesting area (page 43). On the other
hand, a female that is ready to spawn
quietly submits to the aggressive male. The
threat, in which the male spreads his
opercles and shows some display of color,
is followed by attempts to guide the female
to the nest depression. With only mild re-
sistance and casual reluctance, the ripe fe-
male accepts more and more of the male’s
actions and soon enters the nest to remain
with him for periods of time that become
increasingly longer until spawning actu-
ally takes place.
The Spawning Act.—The series of
signals and responses described above cul-
minates when the male and female come
together to deposit their sex products si-
multaneously. Although the aggressive at-
Lartmore: Lire History oF THE WARMOUTH 67
titude of the male makes it seem that he is
controlling the spawning activities, the fe-
male enters the nest only when she is
ready, she gives the final signal (thumping
the male’s side) for extrusion of eggs and
milt, and she leaves the nest depression for
short intervals between egg laying. The
spawning signals and responses follow a
definite sequence; it is interesting to recall
that a female warmouth in a laboratory
spawned alternately during one continu-
ous spawning sequence with two male
warmouths (page 44). After having been
brought to a spawning attitude by one
male, the female then responded to either
of the two nesting males.
Reproductive Isolation. — Hybrids
are produced between the warmouth and a
great number of the species of Lepomis,
and yet such hybrids seldom occur in large
numbers in natural populations. What
forms the reproductive isolation that pre-
vents greater hybridization was not de-
termined in this study. There is little spa-
tial separation of the various sunfishes.
The warmouth is usually found living and
even nesting with several species with
which it could genetically hybridize, and
yet few hybrid individuals are formed. In
the absence of any other observable isolat-
ing barrier, the isolation appears to result
from a lack of the specific signals and re-
sponses necessary to bring a warmouth to
successful spawning with an individual of
another species. In the laboratory, male
warmouths have courted green sunfish and
bluegill females but have not succeeded in
spawning with them and seldom are able
_to guide them to the nest depressions. Ap-
parently, the series of specific signals and
responses is not followed through to suc-
cessful spawning.
Parental Care.—After the warmouth
fry leave the nest area, they receive no
parental care. In ponds and lakes, the fry
scatter into dense weed masses (page 48),
and thus it becomes impossible for the male
parent to keep the young together for close
care. Protection afforded by the dense
weed masses eliminates most of the needs
for parental care. The male warmouth
seems to lack the drive to care for his free-
swimming young; even in a laboratory
aquarium without vegetation in which the
young may hide, he shows little interest in
his fry after they leave the nest.
68
Group Behavior
The warmouth is not a gregarious fish,
even though large numbers of individuals
may be concentrated in a comparatively
small area. The following observations
concern the social relations among war-
mouths.
Agégregations.—There is no_ school
formation among warmouths except that
immediately associated with the nest (page
48). Aggregations form around desirable
cover, such as the riprapping along a dam
(page 8), but little social structure can
be detected in such groups. Even during
the winter, when many fishes form groups,
warmouths show no tendency to gather
together except in response to choice hab-
itats. The nesting colonies that have been
reported (page 42) are probably due to
restricted nesting habitat rather than to a
gregarious nature of the species.
Hierarchy.—To what extent an order
of dominance occurs in a natural war-
mouth population has not been observed.
Attempts at observations on dominance
are hampered by the difficulty of identify-
ing individual fish in a natural setting;
also, the order of dominance becomes com-
plicated by nesting behavior, mating ag-
gression, feeding activities, and local move-
ments.
A hierarchy is quickly established among
warmouths in a restricted group, such as
that in an aquarium. ‘The aggressiveness
of a fish, as for food or space, and the dom-
inance of the fish relative to other mem-
bers of the group, determine its position
in the hierarchy.
the more stable and definite the order of
dominance appears. In groups of more
than three or four, the order may change
frequently. Nesting studies in the labora-
tory revealed that a male in spawning con-
dition tends to assume dominance over one
not so sexually advanced (page 42). The
attitude of aggression which initiates the
breeding behavior temporarily affects any
existing hierarchy.
Witt (1949:34) discovered a definite
hierarchy among five warmouths in an
aquarium. He found no correlation be-
tween the order of dominance and the
errors the fish made in learning to distin-
guish a worm on a hook from a worm that
is free.
ILt”tiIno1is NATURAL History SURVEY BULLETIN
The smaller the group.
Feeding Behavior
Warmouths have a simple pattern of
taking food. When a food item is sighted,
the fish turns toward it, judges its accepta-
bility as food, and then may move in
quickly to snap it up. An unacceptable
food item may hold the warmouth’s atten-
tion for several minutes.
tionless object picked up by a warmouth.
Suction created as the warmouth quickly —
Vol. 27, Art. 1
Seldom is a mo-_
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|
;
opens its wide mouth aids in the capture © .
of food. This suction causes a loud noise —
when the fish gulps an item of food from
the water’s surface and may be responsible
for taking a considerable amount of detri-
tus with the food.
Learning
Witt (1949:27) found that warmouths
could learn to distinguish a worm on a
hook from a free worm. As isolated indi-
viduals, warmouths learned about as quick-
ly as did bluegills and more quickly than
did largemouth bass, but in groups the
warmouths made more errors than did
either largemouths or bluegills. Individ-
uals of all three species exhibited a fair de-
gree of learning, making the majority of
their errors in the first two of the seven
trial periods. After being penalized for
making an error, the warmouth was not
so cautious as the bluegill in its approach
to a hooked worm.
Warmouths do not seem so cautious in
taking fishing lures or so quick in recogniz-
ing artificial situations as most other sun-
fishes. In ponds and in laboratory aquar-
iums, warmouths were seen to strike re-
peatedly at artificial lures without, ap-
parently, becoming suspicious that the lures
were unnatural. In an aquarium, a rest-
ing warmouth, molested by a succession of
lures dangled before its face, apparently
was so undisturbed by the experience that
it turned to snap at a lure more attractive:
to it than the others. On several days at
Ridge Lake, Coles County, Illinois, a fish-
erman repeatedly hooked and released!
what appeared to be the same large war-
mouth by dangling a worm in front of an)
old piece of tile. This warmouth may have
learned, but, if so, its memory did not last
from one fishing trip to the next.
The warmouth’s gullibility toward baits :
August, 1957
may be a desirable trait for a warm-water
sport fish.
ECONOMIC RELATIONS
Warmouths attain their greatest im-
portance as food and sport fish in the lower
Mississippi River valley and states bor-
dering the Gulf of Mexico. There they
are commonly taken with live bait by cane-
pole fishermen. In the midwestern and
eastern states, warmouths usually are not
taken in large numbers but are caught on
a wide variety of baits and lures. Because
of their gamyness and plumpness, they are
attractive to most anglers.
The Warmouth as a Food Fish
The warmouth is now of little commer-
cial value, partly because in most states its
sale is illegal; where it can be legally sold,
the warmouth is not an important food fish
in comparison to the larger species now be-
ing marketed.
In North Carolina during the early
part of this century the warmouth was
taken in gill nets and other nets and sold
throughout the year (Smith 1907:235).
At Reelfoot Lake, Tennessee, in 1937, it
was one of the seven sunfishes that as a
group comprised approximately 10 per cent
of the weight of the commercial catch
(Kuhne 19394:58).
Most people consider the warmouth an
excellent table fish. At times, however,
this fish may have a “muddy” flavor, which
is generally blamed on its association with
silt bottoms and muddy waters, but which
is caused at least partly by the food organ-
isms comprising its diet. Warmouths taken
off silt-covered bottoms of Park Pond usu-
ally had an excellent flavor; they were in-
termediate between the bluegill and the
largemouth bass in both flavor and texture
of flesh.
The Warmouth as a Sport Fish
An early angling critic, Henshall
(1903:59), was very enthusiastic about
the warmouth; he wrote, “For its size, it
is the gamest member of the family except
the black-bass.”’ In a discussion following
a paper by Lovejoy (1903:120), Henshall
pointed out that this sunfish takes a fly
LarimoreE: Lire History oF THE WARMOUTH 69
well, responds to almost any kind of bait,
and is an excellent table fish. Evermann &
Clark (1920:393), Baker (1937:44),
Curtis (1949:266), and others have
praised the fighting qualities of the war-
mouth or have termed it “‘an excellent
small game fish.”
The value of the warmouth as a sport
fish is enhanced by the wide variety of nat-
ural and artificial lures that are effective
in catching it. Through most of its range,
the warmouth is taken more commonly on
natural baits (earthworms, minnows,
grasshoppers, crickets, or grubs) than on
artificial baits.
The yield to the warmouth fisherman,
using either natural or artificial lure, is
often restricted by the difficulty of work-
ing the lure in close enough to weed
masses, brush, and other dense cover to
present it properly to the fish without get-
ting the hook snagged. This difficulty in-
creases during the summer as aquatic vege-
tation grows rank. Floating lures, such as
poppers, are effective during the summer,
because they can be dropped in pockets of
open water among water weeds—where
the warmouths may be hiding, feeding or
nesting—and then be lifted out without
becoming entangled. Worm fishing with
a long pole offers similar advantages in
fishing for warmouths around dense vege-
tation and heavy brush.
Most Illinois fishermen believe that
warmouths may be taken in greater num-
bers during the spring and early summer
than at other seasons. At the Pollywog
Association property and at the flooded
limestone quarries (Fairmount Quarries)
near Fairmount, Vermilion County, good
catches of warmouths are usually made in
May and June but seldom later in the sum-
mer—at least not on the artificial lures
that are relatively effective during the ear-
lier months. Most of the warmouths
caught at Ridge Lake (Dr. George W.
Bennett, unpublished creel records from
Ridge Lake, Coles County, Illinois) have
been taken during the first month of the
- summer fishing season. Although the catch
of warmouths at Lake Glendale (Dr.
Donald F. Hansen, unpublished creel rec-
ords from Lake Glendale, Pope County,
Illinois) was distributed rather evenly in
the period May through August in 1945,
the catch of warmouths in 1946 was much
70 Intinors NarurAL History SuRVEY BULLETIN
higher in April and May than during the
summer months. No warmouths were
taken at Lake Glendale during September
in either year. ‘These records form an in-
teresting contrast with the records of
Ricker (1945:330) for Muskellunge
Lake, Indiana, where a striking increase in
the catch of warmouths occurred during
September.
Censuses of sport fishing reported by
Ricker (1945) for three Indiana lakes
show that warmouths were taken regu-
larly by anglers but not in abundance.
Lewis & English (1949:317) recorded
only four warmouths taken during 6,513
man-hours of fishing in Red Haw Hill
Reservoir, lowa, even though warmouths
were fairly common in the lake. They sug-
gested that the low catch was due to the
difficulties of angling among the dense
marginal vegetation of this lake. Kuhne
(1939a:51) calculated a take of war-
mouths at Reelfoot Lake, Tennessee, that
amounted to 1.02 per cent by weight of
the anglers’ catch for 1937. The combined
catches of resident and non-resident fisher-
men amounted to only 0.02 warmouth per
hour (Kuhne 1939a:48). In a creel cen-
sus for the period March 1 through Sep-
tember 30, 1952 (Cobb 1953:21), war-
mouths comprised 2.05 per cent of the
weight of all fish taken by sport fishermen
at Reelfoot Lake.
Creel records for Illinois lakes show
that the warmouth usually is not abundant
in the anglers’ catches.
In Onized Lake, Illinois, Bennett
(1945:380-3) reported only 105 war-
mouths caught during 7,526.9 hours of
fishing in a period beginning in 1938 and
ending in 1941. This catch represented
about 0.01 warmouth per hour. Even
though this species comprised 18 per cent
of the total number of fish (6 per cent by
weight) in the final census of 1941, it
made up only 2.6 per cent by numbers (2.9
per cent by weight) of all fish caught in
the period of study. Since only a few war-
mouths were caught during a period when
the other sport fish were being severely
cropped in this 2-acre lake, one might
have expected warmouths to replace the
other fish of desirable sizes removed by
angling. However, only 13 warmouths of
6 inches or more in length were recorded
in the final census.
Vol. 27, Art. 1
At Horseshoe Lake, Alexander County,
in southern Illinois, 2 per cent of the fish-
ermen’s catch during the summer of 1956
was composed of warmouths (Bruce ~
Muench, 1956, report to the Illinois De- —
partment of Conservation and Southern
Illinois University).
At Venard Lake, 20 of the 101 war-
mouths planted in this lake early in 1947
were caught by anglers later in the same
year. This take represented about 20 per
cent of the number of warmouths planted —
but only 14 per cent of the total catch.
About 52 per cent of the 240 largemouth ~
bass that had been planted with the war-—
mouths were taken by anglers in 1947.
In 1946 at Lake Glendale, in southern —
Illinois, the percentage of warmouths
in the anglers’ creel was not far be- —
low the percentage of warmouths in the —
total fish population. Warmouths were —
first caught in Lake Glendale the third —
summer after impoundment of the lake in
1940 and they increased in the anglers’
catches during each of three summers fol-
lowing their first appearance (Dr. Donald —
F. Hansen, unpublished creel records from _
Lake Glendale, Pope County, Illinois).
In the last year of the 3-year sequence,
warmouths comprised 4.5 per cent of the —
total number of fish taken. When the ~
lake was drained and the fish population —
censused, warmouths made up 6 per cent _
of the total number of fish and 5 per cent
of the total weight; 57 per cent of the
warmouths were over 6 inches in total
length.
Several central Illinois ponds that, as 4
part of the life history study reported here, ¥
had been stocked with warmouths pro- —
duced hook-and-line yields that were low —
in proportion to the populations of these
fish. The exploitation rate from angling
was proportionally lower than for most — /
other centrarchids inhabiting these waters.
Fly and plug fishermen caught relatively 4
few warmouths; most large catches of war-_
mouths from these stocked ponds were
taken on live baits. |
Warmouth populations in the creeks and —
rivers in most parts of Illinois contribute
very little to the creels of anglers. How-
ever, anglers who fish a few of the streams
of southern Illinois report the common oc-
currence of warmouths in their creels. The
warmouth is probably not abundant |
August, 1957
enough in the Mississippi River from Ca-
ruthersville, Missouri, to Dubuque, Iowa,
to be considered of much importance in the
sport fishery (Barnickol & Starrett 1951:
519).
The Warmouth as a Laboratory Fish
The warmouth is a desirable fish for
laboratory experimentation. It is rela-
tively easy to transport from the field and
to keep alive in the laboratory. It is large
enough to be easily handled and yet small
enough to be accommodated in most aquar-
iums. It has a quiet disposition, quickly be-
comes adapted to laboratory conditions,
and readily feeds on a wide variety of
foods.
In the laboratory, the warmouth will
nest and spawn, apparently undisturbed by
the presence of an observer. The wide va-
riety of foods acceptable to it simplifies the
task of keeping this fish for long periods
in the laboratory. Such characteristics as
its tolerance for low concentrations of dis-
solved oxygen, its rapid color responses to
excitement, and its unusual individual and
group behavior present interesting prob-
lems for study. The warmouth has been
used in Natural History Survey laborato-
ries in studies of food conversion, learning,
group behavior, and marking techniques,
as well as in studies reported in the pres-
ent paper.
The Warmouth in Artificially
Established Populations
Several combinations of species have
been used by fisheries biologists in seeking
to establish fish populations that will pro-
duce and maintain good sport fishing in
lakes and ponds. In some waters, the
largemouth bass and bluegill have seemed
to be suitable companion species (Swingle
& Smith 1941:271). In many Illinois
lakes, however, this combination has not
proved satisfactory, as bluegills have
tended to overpopulate the water (Bennett
1944:186).
Lovejoy (1903:116—-7) considered the
_ warmouth one of the three best species to
be used in stocking small ponds in the
south. He wrote, “It grows to much
larger size than the bream, thick and fleshy,
with large mouth, and is to some extent
LarimMoreE: Lire History oF THE WARMOUTH 71
cannibalistic, but not enough so to make
it objectionable. It will eat a few of its
own young, but not enough to miss them
—yjust enough to make the balance grow
well.”
The stocking of inland waters with war-
mouths for sport fishing was begun before
the turn of the century. Records indicate
that the distribution of warmouths by state
and federal agencies has been sporadic and
probably never on a large scale. For ex-
ample, an Oklahoma state agency distrib-
uted 36,300 fingerlings in the calendar year
1935, and the United States Bureau of
Fisheries distributed 53,160 fingerlings in
the fiscal year ending June 30, 1936
(Earle 1937:16, 23). In the 12-month
period beginning September 1, 1946, a
Texas state agency distributed 134,345
warmouth fingerlings, and in 1947 the
United States Fish and Wildlife Service
distributed 20,348 warmouth fingerlings
and 20 warmouths at least 6 inches in
length (Tunison, Mullin, & Meehean
1949:55,58). The Fish and Wildlife
Service distributed 64,040 warmouth fin-
gerlings in 1949 and 710 in 1950 (Dun-
can & Meehean 1953:5-6) ; 4,600 war-
mouth fingerlings and 610 warmouths at
least 6 inches long in 1951 and none in
1952 (Duncan & Meehean 1954:4—5).
In Alabama, Swingle (1950:49-73)
stocked 10 of 34 experimental ponds with
warmouths in combination with large-
mouth bass, bluegills, and other fishes.
Seven of the 10 ponds containing war-
mouths produced populations that were
considered balanced and 3 produced popu-
lations that were considered unbalanced.
Warmouths comprised less than 6 per cent
of the total weight of fish in all but 1 of
the 10 ponds, a pond with a population
judged to be unbalanced; in this pond
warmouths made up 11.3 per cent of the
weight. Bluegills far outnumbered the
warmouths in each population.
The relatively low proportions of war-
mouths encountered (usually less than
10 per cent by weight, table 4) indicate
that these fish have no tendency to become
dominant at the expense of other kinds of
fishes. However, even these low propor-
tions may represent overcrowding for the
warmouths themselves, as indicated by
slow growth and the occurrence of a high
percentage of small individuals reported in
72 I_tinois NATURAL History SuRVEY BULLETIN
several censuses. Growth studies in IIli-
nois indicate that as low a proportion of
warmouths as 10.4 per cent by weight,
found in Park Pond Slough (a weed-
choked channel in Park Pond) may repre-
sent overcrowding for these fish. Growth
of warmouths in this channel was consid-
erably slower than was that of warmouths
in Onized Lake, just preceding 1941,
when warmouths made up 6.5 per cent of
the total weight of the fish population —
(Bennett 1945:382, 397), and slower
than that of warmouths in Lake Glendale
just preceding 1946, when warmouths
made up 5.0 per cent of the total weight
(unpublished information from Dr. Don-
ald F. Hansen of the Illinois Natural His-
tory Survey). In Onized Lake, the fish
population had been thinned by excessive
fishing, and in Lake Glendale the popula-
tion had been expanding during the 6
years following impoundment of the
water.
Experimental Species Combina-
tions.—As part of a series of manage-
ment experiments by the author, 17 ponds
in central Illinois were stocked with war-
mouths in various combinations that in-
cluded largemouth bass, smallmouth bass,
several pan fishes, and minnows. Because
these experiments have not yet been com-
pleted and because they are not an integral
part of the life history study reported
here, the stocking combinations are listed
below with consideration given princi-
pally to the early development of the pop-
ulations and such factors as directly relate
to the life history of the warmouth.
Warmouths (Adults); Largemouth
Bass (Fingerlings and Y earlings).—This
combination of species and sizes was first
tested in 3-acre Enright Pond over a pe-
riod of 15 months. Sixteen adult war-
mouths, 4 yearling largemouths, and 60
fingerling largemouths per acre were re-
leased in May, 1947. Warmouths spawned
the first summer, and both species pro-
duced broods of young the second sum-
mer. Growth of all fish was rapid; some
of the first-brood warmouths attained
lengths as great as 6 inches in a little more
than a year. There was a desirable distri-
bution of numbers in size groups of both
species.
Warmouths (Fingerlings and Adults) ;
Largemouth Bass (Fingerlings and
Vol. 27, Art. 1
Adults ).—Both species were introduced in —
numbers and sizes simulating a “pyramid —
of numbers.” This combination was tried —
in Enright Pond after termination of the
experiment described above; the popula-
tion was established during the early fall
months of 1948 with 90 fish of each spe-
cies per acre. Moderate-sized broods of
both species were produced the next sum- |
mer, and in each of the seven following
summers the population was studied. —
The striking difference between what oc-
curred in this warmouth-largemouth pop-
ulation and what usually occurs in a blue-
gill-largemouth population was that in the —
Enright Pond population the bass success- —
fully produced a brood each year and fish —
of the companion species (warmouths in —
Enright) never produced such large num- |
bers of young that they dominated the pop-
ulation. In 187 hours of recorded fishing ©
during the sixth summer (there were —
fewer records for other years), 98 large- —
mouths and 16 warmouths were caught —
at a rate that averaged 0.6 fish per hour. —
The number and sizes of fish of each spe- —
cies in this population were more nearly —
constant from year to year than in popu-
lations started with fish of one size.
Warmouths (Adults); Largemouth —
Bass (Yearlings and Adults)—Venard
Lake was stocked in 1947 with 32 adult —
warmouths and 70 yearling and 5 adult ©
largemouths per acre. The growth and —
competition for food in this population ~
have been discussed previously in this pa- —
per. The bass gained an early dominance —
over the warmouths; by the end of the
third growing season, the lake was be-—
coming overcrowded with bass. q
Warmouths (Adults); Largemouth
Bass (Adults). — Fifteen adult war-
mouths and 22 adult largemouths per —
acre were released in Reece Pond in May,
1949. This 2.5-acre pond was character- —
ized by a large proportion of shallow water —
and dense masses of aquatic vegetation —
(Potamogeton foliosus). Both species of —
fish spawned the first summer and they —
produced broods in each of the 7 succeed-—
ing years. The extensive vegetation per-
mitted the survival of more young fish
than could grow well in this pond. ;
Warmouths (Adults); Largemouth
Bass (Adults) Added 1 Year Later.—In
April and May, 1948, approximately 20
August, 1957
adult warmouths were released in a l-acre
pool above Venard Lake. They produced
a large brood in the summer of 1948. The
following spring about 20 adult large-
mouths were added to the pool. A small
brood of bass was spawned, and the young
grew well; by the end of the summer they
were feeding on small warmouths. ‘This
combination and sequence of setting up
the population allowed the warmouths to
become well established, may have limited
Larimore: Lire History oF THE WARMOUTH 73
of sport fishes—was investigated in three
populations containing warmouths and
largemouths.
Three adult warmouths and 30 finger-
ling largemouths per acre were released in
June, 1952, in Parkhill Pond, a 3-acre
pond which contained a large established
population of the bullhead minnow, Pime-
phales vigilax (Baird & Girard). When
the study was terminated at the end of
about a year, which included parts of
Fig. 25.—Central part of Kearney Pond, McLean County, stocked with warmouths and
largemouth bass.
the size of the first bass spawn, and pro-
vided small forage fish for the bass.
Warmouths (Established Population) ;
Largemouth Bass (Adults)—In June,
1951, Kearney Pond (2.5 acres), fig. 25,
containing a small population of war-
mouths, principally yearlings, was stocked
with 5 adult largemouths per acre. In the
following October, 20 more adult bass
per acre were added, along with 40 finger-
ling and adult warmouths per acre. The
warmouths produced a _ moderate-sized
brood in 1951. In 1952, the largemouths
produced a large brood, the warmouths a
relatively small one. This relative spawn-
ing success of the two species was main-
tained in each of the 3 following years, or
until the study was terminated.
Warmouths (Adults); Largemouth
Bass (Fingerlings) ; Minnows.—The in-
fluence of minnows—both as a forage
item and as a predator on the eggs and fry
two breeding seasons, there was an abun-
dance of minnows, the bass and warmouths
had grown exceptionally fast, and the
warmouths had produced broods the first
and second summers. The largemouths,
which were 10 to 12 inches in total length
early in the second season, did not produce
a brood. Since the warmouths spawned
successfully even though an abundant min-
now population was present, it seems likely
that the largemouths would have produced
a brood the next year.
In July, 1948, Lutz Pond contained a
large population of several species of min-
nows, the most abundant of which was the
bullhead minnow. -This 1.5-acre pond was
then stocked with 20 adult warmouths and
60 fingerling largemouths per acre. War-
mouths spawned the first summer (1948)
and produced a large brood; these young
fish grew -rapidly. The warmouths pro-
duced another brood (1949) before the
74 Ittrnors NATURAL History SuRVEY BULLETIN
2-year-old largemouths spawned in 1950.
The minnow population declined rapidly
during the third summer.
Kearney Pond (2.5 acres) contained
minnows (species unidentified) and dart-
ers, Etheostoma nigrum Rafinesque, when
it was stocked in June, 1949, with 10 adult
warmouths and 46 fingerling largemouths
per acre. The warmouths, minnows, and
darters reproduced well in the first sum-
mer. Growth of the sport fishes was good.
The numbers of minnows and darters de-
clined during the summer.
In Parkhill Pond and Lutz Pond,
two broods of warmouths were produced
before the first spawn of bass. In all three
ponds, the abundance of small forage fish
provided food for the warmouths and
largemouths, which grew rapidly; large-
mouths provided some fishing the second
summer; and a bass brood of moderate
size was spawned the third summer in the
presence of two broods of warmouths.
Warmouths (Fingerlings and Adults) ;
Minnows.—In August, 1948, 34 finger-
ling and 14 adult warmouths per acre
were introduced into Longworth Pond (2
acres), which contained a large population
of fathead minnows, Pimephales promelas
Rafinesque. The warmouths spawned suc-
cessfully during the remainder of the 1948
season and again the following summer.
The broods in both years were small; evi-
dently the minnows had a depressive effect
on the warmouth population.
Warmouths (Adults); an Established
Sunfish Population—Three experiments
were conducted to see if a small number of
warmouths could successfully reproduce
and survive in an established population
consisting of several species of sunfishes.
Seven large adult warmouths were
planted in a one-half-acre pond, Green
Gravel Pit, which at the time (June,
1947) contained a population of bluegills,
redear sunfish, green sunfish, and large-
mouth bass. Only one warmouth (orig-
inal stock) was recovered when poison was
applied to the pond in August, 1948. The
warmouths had failed to establish a brood
during the two intervening spawning sea-
sons.
In November, 1949, Taylor Pond (2
acres) was stocked with 69 adult war-
mouths per acre. A few weeks before, it
had been stocked with 100 bluegill fin-
Vol. 27, Art. 19
gerlings, 100 largemouth fingerlings, and —
15 largemouth adults per acre; a few adult
green sunfish, longear sunfish, and bluegills
also were added. The population was
killed during the second spawning season —
(June, 1951); two adults, each a half —
pound in weight, were the only warmouths —
recovered from a rather large sunfish pop- —
ulation (337 pounds per acre). i
Twenty-three adult warmouths were re-
leased in June, 1952, in a 3-acre pond,
McCarty, which contained a new but large
population of bluegills and largemouth —
bass. No young warmouths (definitely —
identified ) were taken from this pond dur-
ing the following 4 years. ;
Warmouths (Adults); Redear Sunfish —
(Adults) ; Smallmouth Bass (Adults and —
Fingerlings).—This combination of spe-
cies was tested in two ponds.
In July, 1951, 2-acre Taylor Pond E
(mentioned in connection with another ex-
periment) was stocked with 21 adult war- —
mouths per acre. These fish produced a —
small brood in the same summer. In the
following fall and spring, 10 fingerling —
and 7 adult smallmouth bass and 17 adult —
redears per acre were added. A small
brood of smallmouths, a moderate-sized
brood of warmouths, and a relatively large —
brood of redears were produced in the —
summer of 1952.
Observations the next 2 years revealed —
the following: The smallmouths produced
a very small brood in 1953 and no brood
in 1954. Growth of the original stock
of bass was good, but growth of both the ~
1952 and 1953 year classes was very poor. —
The warmouths and redears reproduced ~
successfully each year and at first grew at —
satisfactory rates; however, by the spring
of 1955 there were relatively few over
6.5 inches in length.
Sparks Pond (3 acres), fig. 26, was
stocked with 22 adult smallmouth bass in ~
November, 1949. The following spring —
the smallmouths spawned very successfully. —
In June, 25 adult warmouths and 34 adult ~
redear sunfish were added to the popula- —
tion of this pond. Both of these species re-
produced, although the brood of war-
mouths was quite small in numbers. |
During the following 7 years, these ob-
servations were made: Smallmouth bass of —
the first brood (1950) did not grow well
after the first summer. The bass spawned ~
August, 1957
Lartmore: Lire History oF THE WARMOUTH 75
Fig. 26.—South side of Sparks Pond, Woodford County, stocked with warmouths, redear
sunfish, and smallmouth bass.
each year, but the fingerlings disappeared
before attaining 1.5 inches in length. The
only successful brood of bass after the first
was that produced in 1954, which came
after the redear sunfish population had
been reduced in numbers by poison ap-
plied to part of the pond, a tremendous
number of small sunfish had been lost over
the spillway during a severe flood, and
bass of the 1950 brood had become less nu-
merous. Growth in this 1954 brood of
bass was poor.
The redear sunfish spawned very suc-
cessfully each year. The original stock and
the first brood grew very well. Broods
produced later showed much _ slower
growth. After the fourth year, there were
very few redears over 6 inches in length,
although redears of smaller sizes were nu-
merous.
The warmouth population was slow to
develop. Warmouths spawned successfully
each year, but the broods produced were
small. However, by the fourth year war-
mouths were numerous and had become
large enough to be attractive to anglers.
Warmouths; Largemouths; Bluegills
(Adults of One Sex).—Four experiments
Were set up in attempts to produce war-
mouth X bluegill hybrids.
Kearney Pond (mentioned in connec-
tion with other experiments) contained a
4-year-old warmouth-largemouth popula-
tion when 8 adult female bluegills per
acre were added, July, 1955, in an effort
to produce hybrids with the warmouths.
No hybrids were found in the two spawn-
ing seasons after the bluegills were added.
Dunmire Pond (4.5 acres), fig. 27, was
stocked in May, 1950, with 16 adult war-
mouths, 19 adult male bluegills, and 100
fingerling largemouth bass per acre. In
July, 1955, 10 more adult male bluegills
per acre were added. “The warmouths and
largemouths grew well, spawned success-
fully each year, and produced good fish-
ing. The male bluegills grew exception-
ally large (1.2 pounds), but no hybrids
were observed in the first 6 years after the
pond was stocked.
A shallow 3-acre pond on the Univer-
sity of Illinois Golf Course near Savoy
was stocked with 45 adult warmouths, 185
adult female bluegills, and 907 largemouth
bass fingerlings. These fish were placed in
the pond in two groups, one group in each
of the summers of 1949 and 1950. In the
third summer following the original stock-
ing, a large brood of bluegills was pro-
duced; one or more male bluegills must
have been accidentally introduced in 1950.
No warmouth& bluegill hybrids were col-
lected from this pond.
During the summers of 1949 and 1950,
19 adult warmouths and 59 adult male
bluegills were released in Green Gravel
76 Intrnors NaturAL History SuRVEY BULLETIN
Pit, mentioned in connection with another
experiment. Broods of warmouths were
produced in each of these two summers
and the two following summers that the
study was continued. The male bluegills
built nests, but no warmouth bluegill
Vol. 27, Art. 1
minnow population and grow well when
they become large enough to utilize the
minnows as food.
Largemouth bass in a pond with war-
mouths apparently grow faster and pro-
duce better fishing than do smallmouth
Fig. 27.—North arm of Dunmire Pond, Woodford County, stocked with warmouths, large-
mouth bass, and male bluegills.
hybrids were collected. This half-acre
pond, in which a substantial warmouth
population had been developed, should
have offered a desirable situation for hy-
brid production.
General Conclusions About Spe-
cies Combinations.—Several general
conclusions may be drawn from the pre-
liminary observations on these experimen-
tal populations. Usually when sexually
mature warmouths are released in a pond
before the middle of August, they will pro-
duce a brood the same summer. In estab-
lished warmouth populations, a high pro-
portion of each new brood is spawned so
late in the season that the fish are too
small in their second summer of life to
reproduce then. Small numbers of war-
mouths when introduced into a pond over-
crowded with other sunfish seem unable to
establish a population. Warmouths repro-
duce successfully in the presence of a large
bass in a pond with warmouths. There
is little difference in growth rates be-
tween warmouths that develop in a pond
with largemouths and those that develop in
a pond with smallmouths. Warmouths
will not establish a large enough popula-
tion to support angling and materially
reduce the survival of young bass unless
adult warmouths are introduced a year be-
fore adult bass are added, or unless fin-
gerling bass, instead of adults, are intro-
duced with the adult warmouths.
There is no assurance that hybrids will
be produced when bluegills of only one
sex are introduced into a warmouth popu-
lation.
SUMMARY
1. The ecological life history of the
warmouth, Chaenobryttus gulosus (Cuv-
ier), was studied intensively in two habi-
August, 1957
tats of central Illinois: Venard Lake, a
3.2-acre artificial impoundment stocked
only with warmouths and largemouth bass,
and Park Pond, an 18-acre flooded strip-
mine area containing a fish population of
36 species. [he intensive investigations in
these two areas were supplemented by ob-
servations in other habitats and by pub-
lished records on warmouth habitats and
populations.
2. Field observations and published rec-
ords indicated that the warmouth is usu-
ally associated with habitats characterized
by soft bottoms and dense stands of aquatic
vegetation.
3. In the water areas under observa-
tion, small and medium-sized (less than 5
inches total length) warmouths remained
in protected areas of shallow water
throughout the year, whereas larger indi-
viduals spent more time in deep, open wa-
ters.
4. Laboratory experiments supported
field observations demonstrating that war-
mouths are able to survive in water having
very low concentrations of dissolved oxy-
gen. The critical oxygen tension observed
was 2.5 cc. per liter at 20 degrees C. Tol-
erance for low oxygen concentrations al-
lows the warmouth to survive and grow in
a wide range of habitats and to survive
during periods of water conditions that
are generally considered unfavorable to
fish.
5. The food habits of warmouths from
Park Pond and Venard Lake were studied
through a 12-month period. In volume
and frequency of occurrence, the various
food items identified in warmouth stom-
achs showed little similarity in the two
areas, although crayfish and nymphs of
mayflies, dragonflies, and damselflies were
abundantly utilized at both places. Dur-
ing the summer months, feeding activity
was at a peak early in the morning; it
practically ceased in the afternoon.
6. Postlarval warmouths observed in
the laboratory fed first on protozoa and
bacteria. There was a general increase in
size of food items taken by warmouths of
Park Pond and Venard Lake as the fish
increased in size; the percentage of stom-
aches that were empty was higher among
large fish than among smaller ones.
7. In Venard Lake, warmouths and
largemouth bass consumed about the same
Larimore: Lire History oF THE WARMOUTH Vi
kinds of foods, but differences in their feed-
ing habits may have prevented extensive
competition between these species.
8. Seasonal changes in appearance and
weight of gonads indicated that the war-
mouths collected from Park Pond and
Venard Lake attained sexual maturity
when between 3.1 and 3.5 inches total
length and that fast-growing fish matured
earlier in life than did slow-growing ones.
Warmouths over 5.4 inches total length
attained spawning condition earlier in the
nesting season, and spawned over a longer
period, than did fish of smaller sizes. Males
matured slightly earlier in the season than
did females. In central Illinois, the spawn-
ing season for warmouths generally extends
from mid-May through mid-August.
9. An estimation was made of the total
number of eggs in ovaries of warmouths
of different sizes, from different water
areas, and taken at different times of year.
Total egg counts ranged from 4,500 to
63,200 per ovary. Females from Park
Pond consistently produced fewer eggs
than did those from Venard Lake.
10. A month before the beginning of
the spawning season, groups of developing
eggs began moving away from the primor-
dial egg-stock in sexually mature war-
mouth females. There was a gradual with-
drawal of eggs from the egg-stock through-
out the spawning season. Ova in advanced
maturation were resorbed if not spawned
before the cessation of nesting.
11. In all instances of warmouth nest-
ing observed in the field, the male con-
structed the nest, usually near some pro-
jecting object and on a bottom of loose
rubble containing some silt and detritus.
No colony formation was observed.
12. Sex recognition among warmouths
observed in the laboratory was based ap-
parently on behavior and response to court-
ing. Males displayed temporary color
changes during courtship and spawning.
There was evidence that many males and
females spawned two or more times dur-
ing a summer; in some instances, more
than one female contributed to the com-
plement of eggs in a nest.
13. In the laboratory, incubation of
eggs lasted about 34.5 hours at tempera-
tures between 25.0 and 26.4 degrees C.
Immediately after hatching, the prolarvae
dropped to the bottom of the nest. The
78 ILLino1is NatuRAL History SurRvVEY BULLETIN
yolk supply was exhausted in + days, and
the larvae attempted feeble, poorly di-
rected jumps. By the fifth day, they swam
actively. They began feeding by the sev-
enth day; considerable pigmentation had
developed and the caudal fin appeared
homocercal. The 15.7-mm. young were
essentially like an adult in body form.
14. The mathematical relationship (in
inches) between the anterior radius of a
warmouth scale magnified 41 times (S)
and the total length of the fish (L) was
expressed by the equation:
L=0.5278+ 1.048 S
15. In the populations studied, as the
body length of the warmouth increased,
the tail became relatively shorter; differ-
ent mathematical relationships between
standard length and total length were
found for fish of various sizes.
16. The relationship of standard
length in millimeters (L) to weight in
grams (W) was expressed for 866 Park
Pond warmouths by the equation:
log W=-—4.49867+3.04902 log L
17. The coefficient of condition (C)
for 866 warmouths from Park Pond
showed no consistent seasonal cycle. Sea-
sonal variations in condition were greater
in warmouths between 3.3 and 4.2 inches
than in larger fish. Coefficient of condition
increased progressively with increase in
size of fish.
18. The annulus was found to be a re-
liable year-mark in the warmouth. War-
mouths in Park Pond completed the 1949
annulus between April 7 and May 20.
Warmouths in Venard Lake completed the
1949 annulus over a shorter period than
did those in Park Pond, where ecological
conditions in the habitat varied greatly.
Dredging of the shore of Venard Lake
during August, 1948, is believed to have
caused the formation of a false annulus.
19. Females from Park Pond were con-
sistently smaller than males of the same
ages. The difference was small, however.
20. Age was determined for 1,063 war-
mouths from Park Pond; it was found
that fish of certain year classes had con-
sistently grown more rapidly than others.
Growth for all year classes was better in
certain years than in others.
21. The 1946, 1947, and 1948 year
classes in Park Pond showed different
growth patterns for the summer of 1949.
Vol. 27, Art. 1
The fish in each year class grew rapidly
during May and June. Although growth
continued through the summer for the
younger fish, it declined rapidly after
June for the 1946 year class. The 1947
year class showed a growth pattern inter-
mediate between the earlier and later
year classes. Growth rates were different
for warmouths in different parts of Park
Pond.
22. A comparison of length increments
for the first and for later years of life
showed that warmouths in Park Pond
with the greatest length increment for the
first year added to this length advantage
the second growing season. Fish that grew
slowly the first year showed a slight —
growth compensation during the third
year, although they did not overcome the
length advantage held by the larger fish.
23. Three year classes, represented by
1,102 warmouths, were studied in Venard ©
Lake. Fish of the first year class spawned —
in the lake grew faster than did those of ©
succeeding year classes. The length range
in a single year class was greater during
the first summer than in succeeding years.
The average growth in length for war-
mouths in their first 3 years in Venard
Lake was similar to that for warmouths of
comparable ages in Park Pond.
24. Warmouths in Park Pond were
heavily infested with Posthodiplostomum —
minimum, Proteocephalus ambloplites, and —
Camallanus oxycephalus. Except for an ~
infestation of the leech, Illinobdella
moorei, warmouths in Venard Lake were
relatively free of parasites. No direct harm-
ful effect of parasites was established. :
25. Laboratory and field observations —
showed that the warmouth has a quiet dis- —
position. In its reproductive and group ©
behavior, it is similar to other centrarchids, —
but it displays certain behavioral char- —
acteristics peculiar to the species.
26. Reports and field observations dem- —
onstrated that the warmouth is caught on —
a wide variety of baits and lures, and that
warmouth fishing is best during the spring —
and early summer months. The warmouth ©
has been praised by sport fishermen for its
fighting qualities. It is a useful fish for
laboratory experimentation.
27. That warmouths have no tendency
to become dominant at the expense of other
kinds of fishes was indicated by the rela- —
August, 1957 LarirmoreE: Lire History oF THE WARMOUTH 79
tively low proportions of warmouths re-
ported in fish populations of Illinois and
other states. In 17 ponds in central Illinois
stocked with 11 different fish combinations
that included warmouths with other spe-
cies—largemouth bass, smallmouth bass,
and several pan fishes—warmouths tended
to establish small broods each year without
seriously restricting the reproduction or
growth of companion species.
LITERATURE CITED
American Fisheries Society
1948. A list of common and scientific names of the better known fishes of the United States
and Canada. Am. Fish. Soc. Spec. Pub. 1. 45 pp.
Bailey, Reeve M.
1956. A revised list of the fishes of Iowa, with keys for identification. Iowa Ag. Exp. Sta.
Jour. Paper J-2914:325-77; a reprint of pp. 325-77 of lowa fish and fishing, 3rd ed.,
by James R. Harlan and Everett B. Speaker, published 1956 for lowa State Conser-
vation Commission, [Des Moines], 377 pp.
Bailey, Reeve M. (Chairman)
1952. [Report of] Committee on Names of Fishes. Am. Fish. Soc. Trans. 81(1951) :324-7.
1953. [Report of] Committee on Names of Fishes. Am. Fish. Soc. Trans. 82(1952) :326-8.
Baker, C. L.
1937. The commercial, game, and rough fishes of Reelfoot Lake. Tenn. Acad. Sci. Jour.
12(1) :9-54.
Bangham, Ralph V.
1939. Parasites of Centrarchidae from southern Florida. Am. Fish. Soc. Trans. 68(1938) :
263-8.
Bangham, Ralph V., and Carl E. Venard
1942. Studies on parasites of Reelfoot Lake fish. IV. Distribution studies and checklist of
parasites. Tenn. Acad. Sci. Jour. 17(1) :22-38.
Barnickol, Paul G., and William C. Starrett
1951. Commercial and sport fishes of the Mississippi River between Caruthersville, Missouri,
and Dubuque, Iowa. Ill. Nat. Hist. Surv. Bul. 25(5) :267-350.
Beck, John R.
1952. A suggested food rank index. Jour. Wildlife Mgt. 16(3) :398-9.
Bennett, George W.
1943. Management of small artificial lakes: a summary of fisheries investigations, 1938-1942.
Ill. Nat. Hist. Surv. Bul. 22(3) :357-76.
1944. The effect of species combinations on fish production. N. Am. Wildlife Conf. Trans.
9 2184-90.
1945. Overfishing in a small artificial lake: Onized Lake near Alton, Illinois. Ill. Nat. Hist.
Surv. Bul. 23(3) :373-406.
Bennett, George W., David H. Thompson, and Sam A. Parr
1940. Lake management reports. 4. A second year of fisheries investigations at Fork Lake,
1939. Ill. Nat. Hist. Surv. Biol. Notes 14. 24 pp.
Black, John D.
1945. Natural history of the northern mimic shiner, Notropis volucellus volucellus Cope.
Ind. Dept. Cons., Div. Fish and Game, and Ind. Univ. Dept. Zool., Invest. Ind. Lakes
and Streams 2(18) :449-69.
Breder, C. M., Jr.
1936. The reproductive habits of the North American sunfishes (family Centrarchidae).
Zoologica 21(1) :1-48.
Carlander, Kenneth D. ;
1950. Handbook of freshwater fishery biology. Wm. C. Brown Company, Dubuque, Iowa.
281 pp.
1953. First supplement to handbook of freshwater fishery biology. Wm. C. Brown Company,
Dubuque, Iowa. Pp. 277-429.
Carlander, Kenneth D., and Lloyd L. Smith, Jr.
1944. Some uses of nomographs in fish growth studies. Copeia 1944(3) :157—62.
Carr, A. F., Jr.
1940. Notes on the breeding habits of the warmouth bass. Fla. Acad. Sci. Proc. 4(1939): —
108-12.
Clark, Frances N.
1925. The life history of Leuresthes tenuis, an atherine fish with tide controlled spawning
habits. Calif. Fish and Game Comn. Fish. Bul. 10. 52 pp.
Cobb, Eugene S.
1953. The status of commercial and sport fishing on Reelfoot Lake. Prog. Fish-Cult.
15(1) :20-3.
Curtis, Brian
1949. The warm-water game fishes of California. Calif. Fish and Game 35(4) :255-73.
[ 80 ]
August, 1957 Larimore: Lire History oF THE WARMOUTH 81
Duncan, Lee M., and O. Lloyd Meehean
1953. Propagation and distribution of food fishes for the calendar years 1949-1950. U. S.
Fish and Wildlife Serv. Statis. Digest 28. 38 pp.
1954. Propagation and distribution of food fishes for the calendar years 1951-1952. U. S.
Fish and Wildlife Serv. Statis. Digest 32. 36 pp.
Earle, Swepson
1937. Fish culture is big business in the United States. Prog. Fish Cult. 31:1-29.
Elder, David E., and William M. Lewis
1955. An investigation and comparison of the fish populations of two farm ponds. Am.
Midland Nat. 53(2) :390-5.
Evermann, Barton Warren, and Howard Walton Clark
1920. Lake Maxinkuckee: a physical and biological survey. Ind. Dept. Cons. Pub. 7. Vol. 1.
660 pp.
Fish, Marie Poland
1932. Contributions to the early life histories of sixty-two species of fishes from Lake Erie
and its tributary waters. U. S. Bur. Fish. Bul. 47(10) :293-398.
Forbes, S. A.
1903. The food of fishes. Ill. Lab. Nat. Hist. Bul. 1(3):19-70. 2nd ed.
Forbes, Stephen Alfred, and Robert Earl Richardson
1920. The fishes of Illinois (2nd ed.). Illinois Natural History Survey, Urbana. cxxxvi
“i S97 pp-
Hall, Gordon E., and Robert M. Jenkins
1953. Continued fisheries investigation of Tenkiller Reservoir, Oklahoma, during its first
year of impoundment, 1953. Okla. Fisheries Res. Lab. Rep. 33. 54 pp.
Harper, Francis
1942. The name of the warmouth. Copeia 1942(1) :50.
Hennemuth, Richard C.
1955. Growth of crappies, bluegill, and warmouth in Lake Ahquabi, Iowa. Iowa State Col.
Jour. Sci. 30(1) :119-37.
Henshall, James A.
1903. Bass, pike, perch and others. Macmillan Company, New York. 410 pp.
Hile, Ralph
1941. Age and growth of the rock bass, Ambloplites rupestris (Rafinesque), in Nebish Lake,
Wisconsin. Wis. Acad. Sci., Arts, and Letters Trans. 33:189-337.
Holl, Fred J.
1932. The ecology ,of certain fishes and amphibians with special reference to their helminth
and linguatulid parasites. Ecol. Monog. 2(1) :83—107.
Hubbs, Carl L.
1919. The nesting habits of certain sunfishes as observed in a park lagoon in Chicago.
Aquatic Life 4(11) :143-4.
1943. Terminology of early stages of fishes. Copeia 1943(4) :260.
Hubbs, Carl L., and Gerald P. Cooper
1935. Age and growth of the long-eared and the green sunfishes in Michigan. Mich. Acad.
Sci., Arts, and Letters Papers 20(1934) :669-96.
Hubbs, Carl L., and Karl F. Lagler
1947. Fishes of the Great Lakes region. Cranbrook Inst. Sci. Bul. 26. 186 pp.
Huish, Melvin Theodore
1947. The foods of the largemouth bass, the bluegill, and the green sunfish. Master’s thesis,
University of Illinois, Urbana. 35 pp.
Hunt, Burton P.
1953. Food relationships between Florida spotted gar and other organisms in the Tamiami
Canal, Dade County, Florida. Am. Fish. Soc. Trans. 82(1952) :13-33.
James, Marian F.
1946. Histology of gonadal changes in the bluegill, Lepomis macrochirus Rafinesque, and the
largemouth bass, Huro salmoides (Lacépéde). Jour. Morph. 79(1) :63-91.
Jenkins, Robert M.
1953. Growth histories of the principal fishes in Grand Lake (0’ the Cherokees), Oklahoma,
through thirteen years of impoundment. Okla. Fish. Res. Lab. Rep. 34. 87 pp.
Jenkins, Robert, Ronald Elkin, and Joe Finnell
1955. Growth rates of six sunfishes in Oklahoma. Okla. Fish. Res. Lab. Rep. 49. 73 pp.
Jordan, David Starr, Barton Warren Evermann, and Howard Walton Clark
1930. Check list of the fishes and fishlike vertebrates of North and Middle America north
of the northern boundary of Venezuela and Colombia. U. S. Commr. Fish. Rep., 1928,
part 2. 670 pp.
82 Inuinois NaTuRAL History SurveEY BULLETIN Vol. 27, Art. 1
Katz, Max, and Donald W. Erickson
1950. The fecundity of some herring from Seal Rock, Washington. Copeia 1950(3) :176-81.
Kuhne, Eugene R.
1939a. The Reelfoot Lake creel census. Tenn. Acad. Sci. Jour. 14(1) :46-53.
1939). Preliminary report on the productivity of some Tennessee waters. Tenn. Acad. Sci.
Jour. 14(1) :54—60.
Larimore, R. Weldon, Leonard Durham, and George W. Bennett
1950. A modification of the electric fish shocker for lake work. Jour, Wildlife Mgt.
14(3) :320-3.
Lee, Rosa M.
1912. An investigation into the methods of growth determinations in fishes by means of scales.
Counseil Permanent International pour |’Exploration de la Mer. Publications de Cir-
constance 63. 35 pp. Copenhagen.
Lewis, William M., and Thomas S. English
1949. The warmouth, Chaenobryttus coronarius (Bartram), in Red Haw Hill reservoir, lowa.
Iowa State Col. Jour. Sci. 23(4) :317-22.
Lovejoy, Samuel
1903. Fish on the farm—what species to select. Am. Fish. Soc. Trans. 1903:116-25.
McCormick, Elizabeth M.
1940. <A study of the food of some Reelfoot Lake fishes. Tenn. Acad. Sci. Jour. 15(1) :64-75.
Martin, A. C., R. H. Gensch, and C. P. Brown
1946. Alternative methods in upland gamebird food analysis. Jour. Wildlife Mgt. 10(1):
8-12.
Meehean, O. Lloyd
1942. Fish populations of five Florida lakes. Am. Fish. Soc. Trans. 71(1941) : 184—94.
Moore, Walter G.
1942. Field studies on the oxygen requirements of certain fresh-water fishes. Ecology
23 (3) :319-29.
Nelson, E. W.
1876. A partial catalogue of the fishes of Illinois. Il]. Mus. Nat. Hist. Bul. 1:33-52; also
Ill. Lab. Nat. Hist. Bul. 1(1) :33-52.
Reintjes, John W., and Joseph E. King
1953. Food of yellowfin tuna in the central Pacific. U. S. Fish and Wildlife Serv. Fish.
Bul. 54(81) :91-110.
Rice, Lucile A.
1941. The food of six Reelfoot Lake fishes in 1940. Tenn. Acad. Sci. Jour. 16(1) :22-6.
Richardson, R. E.
1913. Observations on the breeding habits of fishes at Havana, Illinois, 1910 and 1911. III.
Lab. Nat. Hist. Bul. 9(8) :405-16.
Ricker, William E.
1945. Fish catches in three Indiana lakes. Ind. Dept. Cons., Div. Fish and Game, and Ind.
Univ. Dept. Zool., Invest. Ind. Lakes and Streams 2(16) :325—44.
Schoffman, Robert J.
1940. Age and growth of the black and white crappie, the warmouth bass, and the yellow
bass in Reelfoot Lake. Tenn. Acad. Sci. Jour. 15(1) :22-42.
Smith, Hugh M.
1896. A review of the history and results of the attempts to acclimatize fish and other water
animals in the Pacific States. U. S. Fish Comn. Bul. 15(1895) :379-472.
1907. The fishes of North Carolina. Vol. 2. 453 pp. North Carolina Geological and Eco-
nomic Survey, Raleigh.
Swingle, H. S.
1950. Relationships and dynamics of balanced and unbalanced fish populations. Ala. Polytech.
Inst. Bul. 274. 74 pp.
Swingle, H. S., and E. V. Smith
1941. Experiments on the stocking of fish ponds. N. Am. Wildlife Conf. Trans. 5:267—76.
Tarzwell, Clarence M.
1942. Fish populations in the backwaters of Wheeler Reservoir and suggestions for their man-
agement. Am. Fish. Soc. Trans. 71(1941) :201-14.
Tinbergen, N.
1953. Social behavior in animals with special reference to vertebrates. Methuen & Co., Ltd.,
London. 150 pp.
Toole, Marion
1946. Utilizing stock tanks and farm ponds for fish. Tex. Game, Fish and Oyster Comn.
Bul. 24. 45 pp. Second printing.
August, 1957 LarrmoreE: LiFE History oF THE WARMOUTH 83
Tunison, A. V., S. M. Mullin, and O. Lloyd Meehean
1949. Survey of fish culture in the United States. Prog. Fisk-Cult. 11(1) :31-69.
United States Weather Bureau
1948. Climatological data. Illinois 53(10—2) :133-200.
1949. Climatological data. Illinois 54(1-9) :1-157.
Upper Mississippi River Conservation Committee
1946. Second progress report of the Technical Committee for Fisheries. 26 pp. Mimeo.
1947. Third progress report of the Technical Committee for Fisheries. 63 pp. Mimeo.
1948. Fourth progress report of the Technical Committee for Fisheries. 41 pp. (Third sec-
tion of Proceedings of Fourth Annual Meeting, Upper Mississippi River Conservation
Committee. 136 pp.) Mimeo.
Venard, Carl Ernest
1941. Studies on parasites of Reelfoot Lake fish. II. Parasites of the warmouth bass,
Chaenobryttus gulosus (Cuvier and Valenciennes). Tenn. Acad. Sci. Jour. 16(1) :14—6.
Witt, Arthur, Jr.
1949. Experiments in learning of fishes with shocking and hooking as penalties. Master’s
thesis, University of Illinois, Urbana. 60 pp.
Some Recent Publications of the
IttiNois NarurAL History SURVEY
BULLETIN
Volume 26, Article 1—The Mayflies, or Ephem-
eroptera, of Illinois. By B. D. Burks. May,
1953. 216 pp., frontis., 395 figs., bibliog. $1.25.
Volume 26, Article 2.—Largemouth Bass in
Ridge Lake, Coles County, Illinois. By
George W. Bennett. November, 1954. 60
pp., frontis., 15 figs., bibliog.
Volume 26, Article 3.—Natural Availability
of Oak Wilt Inocula. By E. A. Curl. June,
1955. 48 pp., frontis., 22 figs., bibliog.
Volume 26, Article 4.—Efficiency and Selec-
tivity of Commercial Fishing Devices Used
on the Mississippi River. By William C.
Starrett and Paul G. Barnickol. July,
1953. 42 pp., frontis., 17 figs., bibliog.
Volume 26, Article 5—Hill Prairies of IIli-
nois. By Robert A. Evers. August, 1955.
80 pp., frontis., 28 figs., bibliog.
Volume 26, Article 6.—Fusarium Disease of
Gladiolus: Its Causal Agent. By Junius L.
Forsberg. September, 1955. 57 pp., frontis.,
22 figs., bibliog.
CIRCULAR
32.—Pleasure With Plants. By L. R. Tehon.
February, 1952. (Fourth printing, with re-
visions.) 32 pp., frontis., 9 figs.
39.—How to Collect and Preserve Insects.
By H. H. Ross. June, 1953. (Fourth print-
ing, with alterations.) 59 pp., frontis., 65
figs.
42.—Bird Dogs in Sport and Conservation.
By Ralph E. Yeatter. December, 1948. 64
pp., frontis., 40 figs.
43.—Peach Insects of Illinois and Their Con-
trol. By Stewart C. Chandler. December,
1950. 63 pp., frontis., 39 figs.
45.—Housing for Wood Ducks. By Frank C.
Bellrose. February, 1955. (Second print-
ing, with revisions.) 47 pp., illus., bibliog.
46.—Illinois Trees: Their Diseases. By J.
Cedric; Carter. “August, °1955.- 99: ‘pp.,
frontis., 93 figs. Single copies free to IlIli-
nois residents; 25 cents to others.
List of available publications mailed on request.
Single copies of ILLINoIs NATURAL History SuRvEY publications for which no price is listed —
will be furnished free of charge to individuals until the supply becomes low, after which a
nominal charge may be made. More than one copy of any free publication may be obtained
without cost by educational institutions and official organizations within the State of Illinois; —
prices to others on quantity orders of these publications will be quoted upon request. '
Address orders and correspondence to the Chief:
ItLtiNotis Natura History SURVEY
Natural Resources Building, Urbana, Illinois
Payment in the form of money order or check made out to State Treasurer of Illinois,
Springfield, Illinois, must accompany requests for those publications on which a price is set.
BIOLOGICAL NOTES
28.—Home Pools and Homing Behavior of
Smallmouth Black Bass in Jordan Creek.
By R. Weldon Larimore. June, 1952. 12
pp., 5 figs., bibliog.
29.—An Inventory of the Fishes of Jordan
Creek, Vermilion County, Illinois. By R.
Weldon Larimore, Quentin H. Pickering,
and Leonard Durham. August, 1952. 26
pp., 25 figs., bibliog.
30.—Sport Fishing at Lake Chautauqua, near
Havana, Illinois, in 1950 and 1951. By
William C. Starrett and Perl L. McNeil,
Jr. August, 1952. 31 pp., 22 figs., bibliog.
31.—Some Conservation Problems of the
Great Lakes. By Harlow B. Mills. Octo-
ber, 1953. (Second printing.) 14 pp., illus.,
bibliog.
32.—Some Facts About Illinois Snakes and
Their Control. By Philip W. Smith. No-
vember, 1953. 8 pp., 11 figs. 10 cents.
33—A New Technique in Control of the
House Fly. By Willis N. Bruce. Decem-
ber, 1953. 8 pp., 5 figs.
34.—White-Tailed Deer Populations in IIli-
nois. By Lysle R. Pietsch. June, 1954. 24
pp., 17 figs., bibliog.
35——An Evaluation of the Red Fox. By
Thomas G. Scott. July, 1955. (Second
printing.) 16 pp., illus., bibliog. 7
36—A Spectacular Waterfowl Migration
Through Central North America. By Frank
C. Bellrose. April, 1957. 24 pp., 9 figs.
37.—Continuous Mass Rearing of the Euro-
pean Corn Borer in the Laboratory. By
Paul Surany. May, 1957. 12 pp., 7 figs.
MANUAL
3.—Fieldbook of Native Illinois Shrubs. By
Leo R. Tehon. December, 1942. 307 pp., ©
4 color pls., 72 figs., glossary, index. $1.50. |
4.—Fieldbook of Illinois mammals. By Donald —
F. Hoffmeister and Carl O. Mohr. June, —
1957. 233 pp., color frontis., 119 figs., glos-
sary, bibliog., index. $1.75.
Printed by Authority of fA&@ 4
the State of Illinois ¥€
A Century of
Biological Research
f HARLOW B. MILLS GEORGE W. BENNETT
GEORGE C. DECKER THOMAS G. SCOTT
_ HERBERT H. ROSS JAMES S. AYARS
_J. CEDRIC CARTER RUTH R. WARRICK
; BESSIE B. EAST
:
STATE OF ILLINOIS e Wu. G. Stratton, Governor
3 DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binxs, Director
3 NATURAL HISTORY SURVEY DIVISION e Hartow B. Mus, Chie}
NATURAL
(3 CO a ees he Dg mes IIL
ILLINOIS NATURAL HISTORY SURVEY
Bulletin
Volume 27, Article 2 ; as
Printed by Authority of
December, 1958 the State of Illinois
A Century of
Biological Research
HARLOW B. MILLS GEORGE W. BENNETT
GEORGE C. DECKER THOMAS G. SCOTT
HERBERT H. ROSS JAMES 5S. AYARS
f CEDRIC CARTER RUTH R. WARRICK
BESSIE B. EAST
STATE OF ILLINOIS e WitiaM G. STRATTON, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION e Hartow'B. Mitts, Chief
Urbana Illinois
STATE OF ILLINOIS
Wintiam G. Srrarron, Governor
BOARD OF NATURAL RESOURCES AND CONSERVATION
Vera M. Binxs, Chairman; A. E. Emerson, Ph.D., Biology; L. H. Tirrany, Ph.D., Forestry; Warter H. Newnouse, |
D.Se., Chemistry:
Ph.D., Representing the President of the
Ph.D., Geology; RocEr AvaMs, Ph.D.,
EvERritt, EE.
President of Southern Illinois University
NATURAL HISTORY SURVEY DIVISION, Urbana,
SCIENTIFIC AND TECHNICAL STAFF
Haritow B. Mixes, Ph.D., Chief
Assistant to the Chie}
Bessie B.
Section of Economic Entomology
Georce C. Decker, Ph.D., Principal Scientist and Head
J. H. Biccer, M.S., Entomologist
L. L. Enouisu, Ph.D., Entomologist
Wiuuis N. Bruce, Pi. D,, Associate Entomologist
poemen Gannon, Ph. Dp. Associate Entomologist
H. Luckmann, Ph.D., Associate Entomologist
ee D. Brices, Ph.D., Associate Entomologist
Ronatp H. Meyer, M.S., Assistant Entomologist
Joun D. Pascuxe, Ph.D., Assistant Entomologist
Ropert SnetsincerR, M.S., Field Assistant
Carot Morean, B.S., Laboratory Assistant
Eucene M. Bravi, M.S., Research Assistant
Ricuarv B. Dysart, BS., Technical Assistant
Recinatp Roserts, A.B., Technical Assistant
James W. Sanrorp, B.S., Technical Assistant
Eart STADELBACHER, B.S., Technical Assistant
Sue E. Watkins, Technical Assistant
H. B. Petry, Ph.D i
Stevenson Moore, III, Ph.D., Extension Specialist in
Entomology*
Joun W. Marreson, M.S., Research Associate*
Zenas B. Noon, Jr., M.S., Research Assistant*
Crarence E. Wuire, B.S., Research Assistant*
Joun Artuur Lowe, M.S., Research Assistant*
J. Daviw HorrMan, B.S., Research Assistant*
Cartos A. Wuire, B.S., Research Assistant*
Roy E. McLaucuuiy, B.S., Research Assistant*
Costas Kousxorexas, M.S., Research Assistant*
Louise ZINGRONE, B.S., Research Assistant*
Mary E. Mann, R.N., Research Assistant*
Section of Faunistic Surveys and Insect Identification
H. H. Ross, Ph.D., Systematic Entomologist and Head
Mirton W. Sanpverson, Ph.D., Taxonomist
Lewis J. Stannarp, Jr., Ph.D., Associate Taxonomist
Puitie W. Smitrn, Ph.D., Associate Taxonomist
Leonora K. Guoyp, M.S., Assistant Taxonomist
H. B. Cunnincuam, M.S., Assistant Taxonomist
Epwarp L. Mockrorp, MS., Technical Assistant
Tuetma H. Overstreet, Technical Assistant
Section of Aquatic Biology
Georce W. Bennett, Ph.D., Aquatic Biologist and Head
Wituiam C. Starrett, Ph.D., Aquatic Biologist
R. W. Larimore, Ph.D., Aquatic Biologist
Davin H. Buck, Ph.D., " Associate Aquatic Biologist
Rosert C. Hirtipran, Ph.D., Associate Biochemist
Dona.tp F. Hansen, Ph.D., Assistant Aquatic Biologist
Wiiuiam F. Cuirpers, M.S., Assistant Aquatic Biologist
Joun C. Cratrey, BS., Field Assistant
Ricuarp E. Bass, Field Assistant
Rosert D. Crompton, Field Assistant
CONSULTANTS: Herrerorocy, Hopart M. Smirn, Ph.D., Professor of Zoology, University of Illinois; Parastro.ocy,
Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of
WILDLIFE RESEARCH, Witiarp D. KLimsTRA,
Ph.D.,
Wildlife Research, Southern Illinois University.
*Employed on co-operative projects with one of several agencies:
Extension Service, Illinois Department of Conservation,
DEPARTMENT OF REGISTRATION AND EDUCATION
East, M.S...
.. Extension Specialist in Entomology*
Assistant Professor of Zoology and Director of Co-operative
United States Army Surgeon General’s Office, United States
Department of Agriculture, United States Fish and Wildlife Service, United States Public Health Service, and others.
(85032—5M—9-58) cigcesapo 2
Vera M. Binks, Director
Rosert H. ANvERSON, B.S.C.E., Engineering; W. L.
University of Illinois; Detyte W. Morais, Ph.D.,
IHlinois
Section of Aquatic Biology—continued
Maurice A, Wuiracre, M.A., Assistant Aquatic
Biologist*
Arnotpo W. Frirz, B.S., Field Assistant*
Davin J. McGinry, Field Assistant*
Section of Applied Botany and Plant Pathology
J. Cepric Carter, Ph.D., Plant Pathologist and Head
J. L. Forsperc, Ph.D., Plant Pathologist
H. Boewe, MS., Associate Botanist
hoe A. Evers, Ph.D., Associate Botanist
E. B. Himeuicx, M.S., Assistant Plant Pathologist
Rosert Dan NeeExy, Ph.D., Assistant Plant Pathologist
Wa ter Hartstirn, Ph.D., Assistant Plant Pathologist
Donaup F. ScHOENEWEISS, Ph.D., Assistant Plant
Pathologist
Rovenia F. Firz-Gerarp, B.A., Technical Assistant
Section of Wildlife Research
Tuomas G. Scorr, Ph.D., Game Specialist and Head
Ra.en E. Yeatrer, Ph.D., Game Specialist
Cart O. Monr, Ph.D., Game Specialist
I. C. Betirose, B.S., Game Specialist
H. C. Hanson, Ph. D., Associate Game Specialist
W. R. Hanson, Ph.D., Associate Game Specialist
Ricuarp R. Graser, Ph.D., Associate Wildlife Specialist
Frances D. Rossins, B.A. Technical Assistant
Vireinta A. Lancpon, Technical Assistant
Howarn Crum, Jr., Field Assistant
Rexrorp D. Lorn, D.Sc., Project Leader*
FrepericK GREELEY, Ph.D., Project Leader*
Gren C. Sanpverson, M.A., Project Leader*
Paut A. Vous, Jr., M.S., Project Leader*
Ronatp F. Lapisxy, M.S., Project Leader*
Jacx A. Exuis, M.S., Assistant Project Leader*
Tuomas R. B. Barr, M.V.Sc., M.R.C.V.S., Research
Assistant*
Bossie Joe Verts, M.S., Field Mammalogist*
Erwin W. Pearson, M.S., Field Mammalogist*
Kennetu L. Jounson, A.B., Field Assistant*
Keira P. Daupuin, Assistant Laboratory Attendant®*
Section of Publications and Public Relations
James S. Ayars, B.S., Technical Editor and Head
Biancue P. Younc, B. A., Assistant Technical Editor
Diana R. BRAVERMAN, B.A., Assistant Technical Editor
Wituiam E. Crark, Assistant Technical Photographer
Marcuerite VERLEY, Technical Assistant
Technical Library
Rutu R. Warrick, B.S., bila Technical Librarian
S
Nett Mies, M.S., B.S. Assistant Technical
Librarian
Veterinary Research, University of Illinois;
University of Illinois, Illinois Agricultural
POWER OR Dp
HE record of one hundred years of
the scientific progress of the Illinois
State Natural History Survey inspires us to
reflect on its origin and brilliant achieve-
ments. We pay the highest tribute to those
early educators and scientists who had vision
beyond the exigencies of the moment.
And we express the highest commenda-
tion to the present Chief, Dr. Harlow B.
Mills, and all of his staff for their contri-
butions to the well-being and pleasure of
our citizens. The important results of their
research extend well beyond the borders of
Illinois.
In contemplating the future, we are con-
fident that this group of dedicated men and
women will meet the increasing demands
for assistance in the problems of the pro-
duction of the necessities of life, that they
will continue their research on the devel-
opment and protection of our natural re-
sources. In the future we may be depend-
ent for our very existence on scientists
such as these. We know they will meet the
challenge.
Illinois is justly proud of the century of
progress of one of its own agencies.
Congratulations!
Vera M. Binks, Director
Department of Registration
and Education
a ty)
{SMI FOREN TK MRE Ras Dayne “of
ne,
01
tee TIT
ro
4 $ -:
rape ee:
The original building of the Illinois State Normal University, Normal, Illinois, spring, 1880.
In this building the Illinois Natural History Society was founded and its museum was housed.
Here the Illinois State Laboratory of Natural History had its headquarters from its founding
in 1877 until late in 1884, and here the fourth State Entomologist was located for approxi-
mately 2 years.
Lt Mt -
CONTENTS
Seerernteoe TO 1958. . oe. ha bee es es 85
Matural History Society...:.......:- 86
State Laboratory of Natural History. 87
Petree MEGMOlOPISE c.f. ss one was oe 88
Benjamin Dann Walsh........... 9]
Wrilliame iu emisavOMs e.fece aes ae 91
RS tg IN OMTAS,H.0) 5 fc, e)s sla ee we eee 93
Stephen Alfred Forbes............ 94
MeUmaaMIAatlION fi. ca. 2s. sucess 97
Natugalsiistory Survey............ 98
MINI Terawenmne Mera eytetes acest nets Gi oo eaelea. & 101
ECONOMIC ENTOMOLOGY.............. 104
Bae ar NSHOEY, 0. koe ce ot vis % nee oie 104
Practical Problems and Progress..... 106
ig So Se ela oS rr 106
Mime te cop estes... 4 oe a ee 111
Cereal and Forage Crop Pests..... 113
Pests of Forest and Shade Trees
afd» Ornamental Plants.......... 118
Insects Attacking Man
SipLCHeN FARINAS ec Sins Gin fe, aan oa ss 119
PQLOpae a MO ONTEO! < cclc secs eee 120
Moalnewoiansect Gontrol. ..2..02. ... 123
Puaphasistor the Future. .2.:...... « 124
PSUIGISUPERIORVEVS 2... foclspe ss e's os 17
PaiiyeSAC RO TOWN: fs c'o ds op kes © 127
Rianpmp selapitats...6 22.) ute. bee. 128
Periods of Faunistic Activities....... 128
Initial Period, 1858-1869......... 129
Expansion Period, 1871-1922......130
Specialization Period,
12s ato. Present. 22) eile ses ks. 132
mesearcn Collections 4.5. ..~...2 4... 134
Ne TRCN LEES ale cuenta ic nls hw a ee Bee 134
Invertebrates Other Than Insects. . 134
NSIS EGER ee Ee Fg roe? ke.’ eterno eg i 134
PEAR IUIG UPR IRE DOLES s otc. acid ck vie 0 bn esc 135
WEEERINGARED i oss: s ie vcs Bas Gv sa arene 135
Invertebrates Other Than Insects. . 137
WSECESNG CNAME, Sie as iss she LS7
PELYOSHEEL AM TOSPECE no. s lane 02 144
\PPLIED BoTANY
BND PLAST PATHOLOGY «0.66.6 35 2 145
Bear liy PA CEINAELES vic 4-ni'e\o- 9 oot ec ks 146
Recent sActivities aac. oe ones eles 149
Plant: Disease'Susveys cs coisa 65% 149
Botanical ‘Collections..: 2... 22.45 152
Shade and Forest
Tree Pathology. .202 20e% 22> oe 154
Floricultural Pathology: .......... 158
Identification and Extension....... 159
Pas amis We resenitcn apcuowits cieocctste nes 160
Uneolveds -Problemss)..<~ +40 -025.. -2' 160
Future Posstbilities..¢ S222. ¢s56 whe 161
PIG UAC Ss EOLOGY = ante nee ete onto rese 163
Beginning of Aquatic Ecology....... 163
First Hield Laboratory: 4 fre oi. 20. 165
Fishes: and: Planktont. ssc ose enc 166
The Fashes ‘of Tilimois snc ee kente 02 on 167
Uline River Plankton) <2.) 5... 167
Bottom F auma.c tees ate ees 168
New. inesvot Research® 2. 20.5. . >. 169
Early Management Attempts........ 170
Modern Management.............. 170
The Last: Ewenty, Yearse.) <0 aac: 172
Direction of Future Studies........ Way)
Wounoiine RESBARGH:. J.)ir54",// \ erates 179
ID emelopment © s..0 cewayacats eee 179
Orennizationncns:.. ale? Ack see 181
Research Contributions: 2...4 es os: 183
Bids Fo Me sau sacs ee eee 183
Viamiima [siete eke cate 195
Wildlite, Management... v2.2... 4. 198
aes UtULe ener as aes hae ee 199
PUBLICATIONS AND PusLic RELATIONS. 202
Karly. Publications. sit? sen 5oee = oe 203
PublicakionsepeLiess tte «> case ws ee 205
Editorial’ Personnel yi: oh cssnc deco: Geert 207
Public selations. > socecc tee) whee BOO
Paitocial Palicyce 446 2: are ato ste 208
PON AR Alec Oye Ei a i ate Nad Oa a a 210
che Library at Notmale.t..5.5...2 210
‘he “Library ae; Urbana 2 ch eck est 210
Library: Collections... (2.22% ..a% se 211
(Cibrary *Petsomel sea: ae soe els
Migancial .SUPPOLE? teece. Halee eee eee
ForMER TECHNICAL EMPLOYEES....... 215
LLEERA TUR DE OULED. con a seach Se 219
*‘punoiSa10§ Ifa] Fy} UT UMOYS de Burpjing aorasas sj} pue asnoyusei3 [eJUeWIadx9 ay fT, “Surpling ay} jo Jy;eyYy ysam ay} Jo jsour
Adnov0 Aaaing AiO SIP] [BANIEN STIOUT[[] Fy} FO Sat1OJe10Ge] PUB SIdyJO UIeW AYT, “OST Ul SSuUIM OM} 9y} ‘OPHT UI pajajdwiod sem Burpying ay} jo jaed
jerjued oyy ‘usredwieyD-eueqig ul sndwied sioul[y FO AjIsIaAtUs) ay} UO BUIP[INgG SadInosay [eINJeN Fy} SurMoys ‘yjnos ay} Woz ‘MaTA [eILIIY
“
gigigiggy |
From 1858 to 1958
ee mid-point of the nineteenth cen-
tury in the United States was marked
by ferment, by excitement, by great
ideas. River traffic was at a peak; rail-
roads had been built and were being ex-
tended. New areas were becoming more
easily accessible to settlers. The point
of departure to the exciting and mysteri-
ous Far West was on the Mississippi
River, and two things happened just
before 1850 which focused attention
on that vast and largely unexplored area
—the movement of the Mormons from
Nauvoo, Illinois, on the banks of the
Mississippi, to the Great Salt Lake, and
the discovery of gold at Sutter’s Mill in
California.
The United States tried its muscles in
the Mexican War in its first inter-
national conflict since its last test with
England, and it ended Mexican domi-
nance in California with the assistance
of the Bear Flag Revolution.
Politically the young country was go-
ing through the series of events which
ultimately led to the Civil War. On
August 27, 1858, the most important of
the Lincoln-Douglas debates, according
to the estimate of some historians, took
place at Freeport, Illinois. This debate
is said to have won for Judge Douglas
the Senatorship in his contest with Lin-
coln, but at the same time it lost the
Presidency for the Judge in a later con-
test with the same adversary.
At the debate, there was a boy of four-
teen who wormed his way to the front
of the crowd and gained some renown
by vocally taking issue with Douglas at
one point in this historically climactic
discussion. “The youngster was consider-
ably chagrined by reproof from _ those
around him, but perhaps he was caught
by the character of that meeting, for it is
reported by George W. Smith (1927:
410) that
There was much confusion—some real dis-
order. . . . It appears from the reports that
orators, reception committees, invited guests,
and newspaper reporters all engaged in a
AKL OW, .B.-M TL Es
hand-to-hand conflict for seats and in
cases for standing room.
some
This boy who had the courage to chal-
lenge Judge Douglas was Stephen Alfred
Forbes, later to be the person most re-
sponsible for the development of the
Illinois State Natural History Survey,
the centennial of which this number of
the Bulletin commemorates.
Not only was this point in history one
of swift movement and of critical impor-
tance in the politics and development of
the country; it also brought science into
clearer focus. Many scientific societies
were organized. Darwin’s Origin of Spe-
cies appeared in 1859. Scientists were
just beginning to play with the idea that
their field was not a mental toy, that it
could be put to practical use; and some
scientists were announcing that they were
interested in the practical application and
popularization of their knowledge, much
to the distress of most of their colleagues.
As an illustration, there is a rather long
apology which Walsh (18684:9) felt con-
strained to include in his First Annual
Report of the Acting State Entomologist.
Apparently this comment was written for
the eyes of Walsh’s scientific confreres;
In part it says:
In a Memoir intended for publication in
the Proceedings of some grave Scientific So-
ciety, it would, of course, be highly indecorous
to break the dreary monotony of scientific
hair-splitting by a single remark, which had
the slightest tendency towards exciting that
convulsive movement of the midriff, which
the vulgar herd of mankind call “laughter.”
. Four hundred years ago Martin Luther
said, that ‘he could see no reason why the
Devil should run away with all the good
tunes.” I can see no reason, in the year 1867,
why the pestilent yellow-covered literature
of the day should monopolize all the wit
and humor. If there is one thing which I
have at heart more than another, it is to
popularize Science—to bring her down from
the awkward high stilts on which she is or-
dinarily paraded before the world—to show
how sweet and attractive she is when the
frozen crust, in which she is usually en-
veloped, is thawed away by the warm breath
of Nature— ... If I merely succeed in en-
ticing away a single young woman from her
[85]
86 I~ttinois NAturAL History SURVEY BULLETIN
mawkish novelettes and romances into the
flowery paths of Entomology, or if I can only
induce a single young man, instead of haunt-
ing saloons and lounging away his time at
street-corners, to devote his leisure to study-
ing the wonderful works of the Creator, as
exemplified in these tiny miracles of perfec-
tion which the people of the United States
call “bugs,” I shall think that I have not
written altogether in vain.
The growth of the population of Illi-
nois resulted in the bringing together,
within the state’s boundaries, of people
with common interests in natural history.
This field of knowledge had not gone un-
noticed in this general geographical area,
but the investigators here were individuals
and worked pretty much alone. Just
across the Wabash River to the east,
Thomas Say had earlier done research
on insects and other animal groups.
Across the Ohio River to the south, John
James Audubon had studied birds.
NATURAL HISTORY
SOCIETY
Because by mid-century people inter-
ested in natural history had become more
numerous in the state, Cyrus Thomas of
Carbondale was able to propose to the
December, 1857, meeting of the State
Teachers’ Association in Decatur that a
Natural History Society of Illinois be
formed (Bateman 1858a). The next year,
on June 30, 1858, the Society was organ-
ized at Bloomington in the office of the
Illinois State Normal University (Bate-
man 18584:258-9). It was given official
sanction and notice when it was chartered
by an act of the state legislature ap-
proved February 22, 1861 (Illinois Gen-
eral Assembly 1861:551-2).
Immediately after its organization the
new Society began the development of a
museum and the collection of scientific
literature.
Among its active members mentioned
by Forbes (1907c:893-4) were C. D.
Wilber, who later became a consulting
mining engineer; Dr. J. A. Sewall, who
later became President of the University
of Colorado at Boulder; Major J. W.
Powell, who was to gain renown as an
explorer in the West; Dr. George W.
Vasey, for many years botanist with the
United States Department of Agricul-
Vol. 27, Art. 2
ture; A. H. Worthen, head of the first
Illinois State Geological Survey; Cyrus
Thomas, Benjamin D. Walsh, M. S.
Bebb, Dr. Oliver Everett, James Shaw,
Dr. Henry M. Bannister, Dr. J. W.
Velie, Professor J. B. Turner, Dr. Ed-
mund Andrews, Dr. Frederick Brendel,
and Newton Bateman. The above list in-
dicates a great breadth of interest and no
lack of intelligence on the part of the —
original members of the Society.
The first officers of the Society included
a General Agent, among whose duties
were the collection and exchange of speci-
mens (Batemen 18584:258). C. D. Wil- —
ber was named to this office. The Society’s —
original constitution (Bateman 1858): ©
258) and the revised constitution of
1859 (Francis 1859b:662-3) provided
that all specimens should be deposited in
the Museum of the State Normal Uni-
versity.
The constitution as revised on June 20,
1859 (Francis 18594:662-3), dropped
the General Agent, gave most of his du-
ties to a newly created Superintendent,
and added a Curator, whose duties were
to receive and arrange specimens. Cyrus
Thomas, who was elected Curator, lived
in Jackson County, many miles from the
Museum, and the elected Superintendent, ~
Wilber, who taught geology at the State
Normal University, according to Mar-
shall (1956) acted as unofficial curator.
At the 1860 meeting, R. H. Holder of
Bloomington was named both Curator
and Treasurer (Wilber 1861a:538).
The state charter of 1861 gave the
Society authority to establish its own
Museum at the State Normal University
(Illinois General Assembly 1861:551),
and officers of the Society set December
25, 1861, as the date on which the Mu-
seum was to be “dedicated, with appro-
priate exercises, aS € FREE OFFERING TO —
THE CITIZENS AND SCHOOLS of Illinois”
(Wilber 1861c:675).
Forbes (1907c:893) listed Sewall,
Powell, Vasey, and himself as curators —
of the Society's Museum, Vasey serving —
only nominally as Powell’s deputy. Powell —
was named Curator by the State Board of —
Education on March 26, 1867.
on the same day by the Directors of the
Natural History Society (Bateman 1867:
His ap- —
pointment was ratified and consented to
|
|
_ December, 1958
tor of the
MILts:
8). Forbes was appointed to the same
office on June 26, 1872, the day Powell’s
resignation was offered and_ accepted
(Bateman 1872:6).
Because the Natural History Society
was composed principally of people who
were prosecuting natural history investi-
gations as sidelines to other activities, and
because it was not a strong cohesive agent,
it finally reached the point where it could
no longer sustain itself. Forbes (1907c:
898) said of the times, “It should be
remembered, in this connection, that this
was a time when college men, as a rule,
worked like dray-horses and were paid
like oxen, De
The Society turned to the state for
aid, and by an act approved February 28,
1867, $2,500, to be paid annually to the
State Board of Education, was appropri-
ated by the General Assembly for the
salary of a curator and “for the necessary
expenses of improving and enhancing the
value” of the Museum (Illinois General
Assembly 1867:21). Major Powell was
the first curator to receive state aid. The
state appropriations, according to Forbes
(1907c:895), “were largely drawn upon
to outfit and maintain the Powell expedi-
tions to the far west.” As a condition
upon receiving further state aid, as pro-
vided by legislative act approved April
14, 1871, the Society had to turn its Mu-
seum over to the state (Illinois General
Assembly 1872:152). On June 22, 1871,
the Society agreed to the transfer and
when, on June 28, 1871, the Board of
Education accepted the transfer, the Mu-
seum officially became state property
(Bateman 1871:9; Forbes 1877 :324-5).
On December 15, 1875, the State
‘Board of Education passed the following
resolution (Etter 1876:17):
Resolved, That we regard the Museum as a
State institution, devoted to the prosecution of
a natural history survey of the State, to the
encouragement and aid of original research,
and to the diffusion of scientific knowledge
and habits of thought among the people.
Forbes, who in 1872 had been appointed
by the State Board of Education as Cura-
Museum, remained in that
capacity until July 1, 1877, when by legis-
lative act approved May 25, 1877, a State
Historical Library and Natural History
Museum were established at Springfield,
Irom 1858 ro 1958 87
and the I1linois Museum of Natural His-
tory at Normal was “converted into a
State Laboratory of Natural History”
(Illinois General Assembly 1877:14—-6).
STATE LABORATORY
OF NATURAL HISTORY
The act that established the State
Laboratory of Natural History relieved
Forbes of the necessity of developing mu-
seum exhibits and allowed him to turn
more of his attention to research. Shortly
after the establishment of the Laboratory,
Forbes’ title was changed from Curator
to Director (Etter 1877:25).
Forbes had not been occupying his time
completely in the preparation of museum
material while he was Curator of the IlIli-
nois Museum of Natural History. He had
taught classes in zoology at Illinois State
Normal University and he had started a
series of bulletins reporting on research
and investigation. The first number of the
series is dated December, 1876, and carries
the title, Bulletin of the Tanats Museum
of Nigiucel History. From the appearance
of No. 2 of the first volume, in June,
1878, until the beginning of Volume nae
in 1918, the title was the Bulletin of ae
State Laboratory of Natural History, and
from that time to the present it has been
the Bulletin of the Illinois State Natural
History Survey or Illinois Natural His-
tory Survey Bulletin. ‘The volumes have
been numbered serially from December,
1876, to the present time.
The work of the Laboratory and its
young Director attracted the attention of
the new Illinois Industrial University at
Urbana. Not only had Forbes been pub-
lishing actively, but in 1882 the duties of
State Entomologist had fallen on his capa-
ble shoulders. Shortly afterward the Uni-
versity made an offer of employment to
the Director of the Laboratory and State
Entomologist. Forbes faced the choice of
declining the offer, of abandoning the
Laboratory, which had been established at
the Illinois State Normal University by
legislative act, or of moving the Labora-
tory with him.
Apparently at his suggestion, the mat-
ter was taken up with the State Board of
Education by the Trustees of the Illinois
Industrial University, and an agreement
88
was made that the law be changed to
allow for the move. In a report addressed
to the Regent and dated December 12,
1884. Forbes made known his needs at
the University (Burrill 1887a:10). He
stated:
As you are doubtless aware, I have for
some time held the position of Director of
the State Laboratory of Natural History, lo-
cated in the Normal University building at
Normal, and, indeed, still remain in nominal
charge of that establishment, having received
from the State Board of Education a leave
of absence, without pay, from January 1 to
June 30, 1885, in order to enable me to enter
upon my duties in the University here. If I
believed that my acceptance of a chair in
this University necessarily involved an inter-
ruption or serious modification of the work
which I have organized as Director of the
State Laboratory of Natural History, I should
keenly regret it; and, indeed, I did not ex-
press my acceptance of that position until I
had arranged a plan of readjustment which
I thought adequate to prevent such a con-
tingency.
Later in the same meeting, Trustee
Alexander McLean offered the following
resolutions (Burrill 1887a:18) :
Resolved, That the Trustees of the Illinois
Industrial University have heard with great
satisfaction the suggestion that the State Lab-
oratory of Natural History may be united with
the University under their charge.
Resolved, That in case such a union shall
be accomplished they will, to the extent of
the means intrusted to them, aid in carrying
forward the valuable work of the laboratory,
by assigning to it suitable apartments in the
building of the University, and by providing
such conveniences as the nature of the work
may require, to the end that it may enjoy
a commodious and perpetual home within,
and the generous cooperation of, an institu-
tion founded and maintained for the promo-
tion of scientific research and the dissemina-
tion of practical knowledge.
Forbes officially took over his duties at
Urbana on January 1, 1885 (Forbes
1886/:Lx).
In the following March the Regent,
Dr. Selim H. Peabody, had the following
comment (Burrill 1887a:19-20) :
The unsuccessful effort of three years ago
to secure for the University the presence and
aid of Prof. S. A. Forbes for the organization
of the instruction of Zodlogy was renewed
last year, and has been crowned with better
fortune. Since the opening of the new year
the Zodlogical laboratory has become an ac-
tive agency in this department of physical
science, and its success is well assured. A
new interest has been aroused in this science.
I~ttinotis Natura History SurvEY BULLETIN
Vol. 27, Art. 2
The office of the State Entomologist has
found a home, it is to be hoped permanent,
where it naturally belongs. The governing —
board of the Normal University has unani-
mously resolved that the State Laboratory
of Natural History should find its proper
abode here at the State University, and has
consented that the property peculiar to the
work of that [laboratory] may be transferred —
hither. This change requires only legislative
action before it can legally go, as it has prac-
tically gone into effect, and there appears to
be little doubt that such action will be taken —
during the present session.
The legislature approved the action,
and everything was legal.
On July 1, 1885, the appointment of
Forbes as Professor of Zoology and En-
tomology at the University of Illinois
(previously Illinois Industrial University)
at an annual salary of $1,160 was ap-
proved by the Board of Trustees, which
also appointed Forbes Director of the
State Laboratory of Natural History and
authorized him to receive laboratory prop-
erty transferred by the State Board of
Education (Burrill 1887a:50). It is inter-_
esting to note the size of the Laboratory
staff at that time. On September 8, 1885,
the Trustees approved the following ap- —
pointments (Burrill 1887a:55-6) :
Entomological Assistants
Thomas F. Hunt $40 a month —
Clarence M. Weed $40 a month
Botanical Assistant
Charles F. Hart $45 a month
Amanuensis
Miss Mary J. Snyder $45 a month
Services relating to botanical survey
Prof. T. J. Burrill $300 for the year
F. S. Earle $83 1/3 a month
Such other miscellaneous assistants as
might be required and within the
funds available
The State Laboratory of Natural His-
tory continued under that name until —
1917;
STATE ENTOMOLOGIST
The rapid settlement of Illinois during
the middle of the nineteenth century
brought in a great number of agricul-
turists. The country was new, and the
breaking down of the original vegetation
for the establishment of fields in which
crops were grown brought about great
losses from insects.
These losses, while |
December, 1958 MILts:
seen and experienced, were not well un-
derstood. Official entomology was born
during this period. The agriculturists felt
the need of assistance and cried out to the
government for it.
At the end of the Civil War, the Presi-
dent of the young Illinois State Horticul-
tural Society, John P. Reynolds, spoke
vigorously on the subject at the December
19, 1865, meeting of the Society at Nor-
mal. In his retiring address, Reynolds
(1866:8) said:
And, first, the appointment of a STATE
ENTOMOLOGIST. The time has been in this
State when it required some moral courage
for any one to advocate the appointment and
compensation from the treasury of an officer
to look after the bugs, but I venture the
opinion that there is no subject in which you,
as amateur or professional horticulturists,
have a more direct, immediate or larger pe-
cuniary interest, than in Entomology—
No one who has given the subject any atten-
tion will question the truth of the statement
that the people of Illinois are to-day many
From 1858 ro 1958 89
millions of dollars poorer by reason of
noxious insects; nor the additional statement
that a very large proportion of this loss
might have been averted by the labors of a
competent Entomologist with a little means
at his disposal.
In 1866 the Horticultural Society,
meeting at Champaign, passed the fol-
lowing resolution (Deyo 1867:58) :
Resolved, Vhat we most urgently pray the
honorable legislature of our great state to
appoint a State Entomologist, that Agricul-
iurists and Horticulturists may not quite
despair of ever overcoming the giant insec-
tiforous [sic] difficulties in the way of suc-
cess in their professions. As one eminently
qualified, and the highest in his profession
in the whole west, we most hopefully mention
the name of Benjamin D. Walsh, of Rock
Island.
The Horticultural Society was not
alone in this movement. At a meeting of
the executive committee of the Illinois
State Agricultural Society on January 3,
1866, G. W. Minier offered the following
University Hall on the University of Illinois campus. This building, completed in 1874 and
razed in 1938, was headquarters for the Illinois State Laboratory of Natural History and the
Office of State Entomologist for a few years after they were moved from Normal to Urbana.
90 Ittinois NATURAL
specific and forthright resolution (Reyn-
olds 1868:18) :
Resolved, That whenever a sum of fifteen
hundred dollars ($1,500) shall have been
obtained, by legislative action or otherwise,
for an annual salary, this Board will then
appoint a competent scientific man as State
Entomologist.
Resolved, That Mr. B. D. Walsh be and he
is hereby appointed State Entomologist, sub-
ject to the preceding resolution.
The legislature listened to these pleas
and in 1867 passed a law which author-
ized the Governor, with the consent of the
Senate, to appoint a state entomologist.
The work of this officer was considerably
handicapped. While he was voted a salary,
he was given no work fund, and the first
Hisrory Survey BULLETIN
Vol. 27, Art. 2
three persons to hold the position main-
tained their offices in their homes or in
offices devoted to other purposes. The job
was a difficult one, and Forbes (1915:
7-8) once rather facetiously wrote:
He [Walsh] performed as well as he could
his various duties of private, captain, colonel,
adjutant, and major-general of this new
force—and in two years he was dead. He
had two successors enlisted for the war on
precisely the same terms, the first of whom,
Dr. Wm. Le Baron, of Geneva, Illinois, main-
tained for five years the unequal contest,
when he also died; and the second, Dr. Cyrus
Thomas, of Carbondale, abandoned the field
in despair after seven years of diligent sery-
ice, going then to Washington for work in
another department of science, where he lived
to the good old age of eighty-five. I have
sometimes wondered if his long survival was
Benjamin Dann Walsh, State Entomologist, 1867-1869.
December, 1958 Mitts:
not largely due to his fortunate escape from
an untenable situation.
Forbes set out to disprove this conten-
tion, and carried the duties, however with
more help than his predecessors had, from
1882 to 1917, a span of 35 years.
Let us now look at the four men who
carried the title and responsibility of Illi-
nois State Entomologist.
Benjamin Dann Walsh
Although the resolutions passed by the
State Horticultural Society and the State
Agricultural Society in 1866 mentioned
specifically Benjamin D. Walsh as a
potential State Entomologist, Walsh did
not obtain this title without some compli-
cations. An act providing for this officer
was passed by the legislature and was
approved on March 9, 1867 (Illinois
General Assembly 1867:35-6). No ap-
pointment was made at that time. How-
ever, a special session was called on June
11 of the same year, and at that time the
name of Walsh was presented for the Sen-
ate’s approval. The session was called for
specific purposes, of which the approval of
an appointee as State Entomologist was
not a part. Therefore, the Senate decided
that constitutionally it could not act on
this matter.
Walsh acted as State Entomologist,
without legal status, and with an assign-
ment of $500 by the Horticultural So-
ciety, until the legislature passed an act
“for the relief of the state entomologist,”
March 25, 1869 (Illinois General Assem-
bly 1869:53-4). This act legalized what
Walsh had been doing for nearly 2 years.
It is interesting to note that Walsh’s first
annual report was made to the Horticul-
tural Society and not to the Governor,
and was signed by Walsh (18684:3) as
Acting State Entomologist.
Walsh was a most interesting person.
He was born in Frome, Worcestershire,
England, September 21, 1808 (Weiss
1936:234). He was well educated, and,
about 1830, received a Master of Arts
degree from Trinity College, Cambridge,
where he was a classmate of Charles Dar-
win. He was married in England, and in
1838 he came to America. His wife had
relatives in Henry County, Illinois, and
he purchased a 300-acre farm in that part
of the state. He operated the farm until
FROM
1858 to 1958 91
1851, when he moved to Rock Island and
entered the lumber business.
He was not a politician, but in 1858,
when he suspected that the city was being
cheated by the city council, he placed his
name in contention for alderman. His
purpose was to get at the city’s books.
This action did not endear him to some
elements of the city, and his life was
threatened. Undaunted, he went ahead
with a successful campaign, exposed the
frauds, and resigned.
Although he had made a small collec-
tion of insects in England, he publicly had
shown no deep interest in entomology
until January, 1860, when he lectured for
2 hours to the State Horticultural Society.
Thereafter he contributed regularly to the
Prairie Farmer and other agricultural
journals. Further, in the proceedings of
scholarly societies, he published several
excellent scientific papers on insects. He
collaborated with E. T. Cresson, A. R.
Grote, and J. W. McAllister in the pub-
lication of a monthly called the Practical
Entomologist, which lasted for only 2
years, until September, 1867. In Septem-
ber of the following year, Walsh and C.
V. Riley started the American Entomolo-
gist.
On November 12, 1869, as Walsh was
walking down a railroad track, busily
engrossed in reading a letter, a train ap-
proached. When he saw the train, he was
too late to clear himself completely, and
his left foot was badly injured. The foot
was amputated, and to console his wife he
said, “Why, don’t you see what an ad-
vantage a cork foot will be to me when I
am hunting bugs in the woods: I can
make an excellent pin-cushion of it, and if
perchance I lose the cork from one of my
bottles, I shall simply have to cut another
one out of my foot” (Riley 1869-70:65).
He published an article exonerating the
engineer from all blame in the accident.
He appeared to be recovering well from
the accident when suddenly he began to
decline, apparently from some internal
injury. He passed away on the 18th of
November, 1869.
William Le Baron
In 1870 Governor John M. Palmer
requested William Le Baron to take over
the position left vacant by the unfortunate
92 Intinois NATURAL History SURVEY BULLETIN
death of Walsh. This request was quite
unexpected, for entomology was only an
active side interest of this competent
physician.
Things which are half-said in history
pique the imagination. We find that Dr.
Goding (1885:123), in a biographical
sketch of Le Baron, had the following to
say:
In 1870 two candidates appeared for the
office of Illinois State Entomologist made va-
cant by the untimely death of the lamented
Walsh—Dr. Henry Shimer of Mt. Carroll
and Mr. Emery of the Prairie Farmer, both
of whom were well qualified for the position.
For reasons that cannot be given at this time,
Gov. Palmer refused to appoint either, but
Vol. 27, Art. 2
named Dr. Le Baron for the place, taking him
entirely by surprise.
Le Baron was a native of North An-
dover, Massachusetts, where he was born
October 17, 1814. He came from a line
of New England professional people; his
father was a medical doctor and _ his
maternal grandfather was Dr. Thomas
Kittredge, a well known and highly re-
spected surgeon of his day.
Le Baron’s calling was decided at an
early point in his life. After studying
medicine under an uncle, Dr. Joseph Kitt-
redge, he practiced for several years in his
home town. Later he completed his medi-
cal studies and was graduated from the
William Le Baron, State Entomologist, 1870-1875.
December, 1958 MILs:
Harvard Medical College. In 1844 he
moved to Geneva, Illinois, where he con-
tinued a successful career as a physician.
As a child he was greatly interested in
nature, moving from ornithology to botany
to entomology. In 1850, after 6 years in
Illinois, he published his first article, a
From
1858 ro 1958 93
way. He died on October 14, 1876. The
excellence of his four reports is a measure
of the high ability that Le Baron possessed.
Cyrus Thomas
The third State Entomologist did not
attend college (Goding 1889:106). The
Cyrus Thomas, State Entomologist, 1875-1882.
treatise on the chinch bug, in the Prairie
Farmer. This study was so exhaustive
that Asa Fitch, the New York State En-
tomologist, republished it in his Second
Report. In 1865 Le Baron was made the
entomological editor of Prairie Farmer.
In the position of State Entomologist
he labored diligently until his health gave
competence Cyrus Thomas attained was
the result of his own personal labors. He
was a versatile and practical person. He
was born in Tennessee, July 27, 1825,
and his mother had hoped that he would
become a physician. In 1849 he moved to
Jackson County, Illinois; where he stud-
ied law and taught school. In 1851 he
94 Intinois NaturAL History SurvVEY BULLETIN
was admitted to the bar and was elected
county clerk. About 1864 he dropped
law and entered the ministry.
For some time, Thomas had considered
entering the field of science and, as evi-
dence of his practicalness, in 1856 he de-
liberately began the study of entomology
as being a field which was inexpensive and
in which there was an abundance of ma-
terial close at hand upon which he could
work. He became an authority on the
Orthoptera. He wrote many articles on
entomology, some of which he contributed
to farm journals.
From 1869 to 1874 he was associated
with the federally sponsored Hayden Geo-
logical Survey, paying special attention to
the entomology and agricultural resources
of the West. During this period he pub-
lished many reports of entomological
significance.
In 1874 Thomas was elected to the
Professorship of Natural Sciences at
Southern Illinois Normal University,
whereupon he severed his relationship with
the federal survey. The next year, 1875,
he was appointed by Governor Richard
J. Oglesby to take the place of Dr. Le
Baron as State Entomologist. Six re-
ports were published by Thomas and his
collaborators.
On March 3, 1877, the United States
Entomological Commission was authorized
by Congress. Thomas found time, along
with his regular work, to become a mem-
ber of this Commission. Other members
of the Commission were C. V. Riley and
A. S. Packard, Jr. Thomas was not col-
laborating with amateurs when he joined
these two men on the Commission. Both
were giants in the profession—names that
still command respect. Riley was State
Entomologist for Missouri, as well as a
member of the Commission, and the real
originator of entomological research in
the federal government. Packard was a
scholarly gentleman, a member of the
National Academy of Sciences and other
learned groups, and an author of note in
his field.
Thomas was a man of real capability,
holding, as he did simultaneously, a pro-
fessorship at Southern Illinois Normal
University, the State Entomologist’s re-
sponsibility, and membership on the his-
toric federal Entomological Commission.
Vol. 27, Art.
Thomas was interested in many things,
and in July, 1882, he resigned his various
Illinois positions and accepted employ-
ment in the Smithsonian Institution’s Bu-.
reau of Ethnology, leaving a brilliant and
uncompleted career in entomology. He
was to gain further laurels in archeology
and to become an authority on the Mayan
language.
About some things he was adamant. He
published a review of Darwin’s works
from an orthodox view, which so im-
pressed the officials of Gettysburg College
that they hastened to award him an honor-
ary Ph.D. degree. |
Thomas lived to be 85 years old, pass-
ing away on June 27, 1910.
He bears a peculiar relationship to the
Natural History Survey, for he is credited
with having first proposed an I]linois Nat-
ural History Society in 1857, and he was
a State Entomologist. .
Thomas was a man of multiple apti-
tudes, as the above sketch indicates. He
moved his intellect in many fields: school
teacher, lawyer, county official, minister,
entomologist, explorer, college professor,
and archeologist.
Stephen Alfred Forbes
No one has molded the character of the
Natural History Survey so much as Dr.
Forbes, a man of irrepressible intellect
and insatiable curiosity, and the fourth ©
and last Illinois State Entomologist.
Forbes was born of pioneer parentage
on May 29, 1844, in Stephenson County, —
Illinois. He was one of a large family. —
His father died when he was 10, and a
brother assumed the responsibility for an_
invalid mother, Stephen, and a younger —
sister. Stephen attended district school un- —
til he was 14, and his brother carried on
his education for 2 more years. For a
short time in 1860 he attended Beloit —
Academy. He had an innate interest in —
language, and on his own he learned to
read French, Spanish, and Italian. ‘
When the Civil War broke out in ©
1861, Forbes was 17. He joined Company ~
B, 7th Illinois Cavalry, in September of
that year. He rapidly advanced from or- —
derly to sergeant to lieutenant to captain,
reaching the last rank when he was 20.
In 1862 he was captured while carrying
dispatches near Corinth, Mississippi, and
Mitts:
December, 1958
From 1858 ro 1958 95
Stephen Alfred Forbes in the 1880’s, while State Entomologist and Director of the State
Laboratory of Natural History at Normal.
was in Confederate prisons for + months.
During this period of enforced idleness
he studied Greek from books he managed
to buy at Mobile. He participated in 22
military engagements, and, other than
suffering from scurvy and malaria while
in prison, he emerged from the war
unscathed.
At the end of hostilities he entered
Rush Medical College in Chicago. Be-
cause of lack of funds and certain psy-
chological difficulties revolving around
surgery without anesthesia, he never fin-
ished the course. After leaving Rush, he
taught school and, on the side, studied
natural history. His first publications ap-
peared in 1870, and these led to his ap-
pointment in 1872 as Curator of the
Museum established by the State Natural
History Society at Normal. He held this
position until 1877, when he was appoint-
ed to head the State Laboratory of Na-
tural History, the child of the Museum.
After the resignation of Thomas as
State Entomologist in 1882, Governor
Shelby M. Cullom appointed Forbes to
that position. In 1884 Indiana University
awarded Forbes the Ph.D. degree “‘by
thesis and examination.” He did not have
a bachelor’s degree. In 1885 he moved to
96 IttrNors NATURAL History SurRvVEY BULLETIN
the University of Illinois, where he was
Professor of Zoology and Entomology,
Director of the State Laboratory of Nat-
ural History, and State Entomologist.
He was Professor of Zoology for 25
Vol. 27, Art. 2
he directed the first forest surveys of IIli-
nois. These represent only a few of his
innumerable interests.
He was a member of many learned so-
cieties and the recipient of many honors.
Stephen Alfred Forbes in about 1915, shortly before being named Chief of the IIlinois
Natural History Survey at Urbana.
years, Professor of Entomology for 13
years, and Dean of the College of Science
for 16 years.
He was especially interested in the in-
teractions of organisms and has_ been
called ‘‘the father of ecology.” His inter-
ests covered all of biology. He investigat-
ed or directed investigations of the food
of fishes and birds, the fishes of the state,
and the biology of the Illinois River, and
Beyond this, he was active in his church,
helped organize the first golf club at the
University, was a member of a _ hiking
club, and late in life delighted in driving
an automobile. On his eightieth birthday
he was arrested for speeding, an incident
which gave him some pleasure.
When the State Laboratory of Natural
History and the State Entomologist’s Of-
fice were united in 1917 to form the Nat-
1958 MILLs:
December,
ural History Survey, Forbes became the
first Chief of the new organization. He
held this position until his death, March
13, 1930, when almost 86 years of age.
The four sketches above cannot do jus-
tice to the entomological pioneers who
are their subjects, but they will give
some indication of the high quality of the
men. All were competent individuals with
wes
SP SK
af
The Natural History Building on the University of Illinois campus.
From 1858 to 1958 97
the State Laboratory Bulletin by Uni-
versity staff members.
The State Entomologist’s responsibili-
ties changed as time went on, and the
agency became responsible for the admin-
istration of some laws, as well as for
research (Forbes 1909:64-5). With the
discovery of the San Jose scale in Illinois
in 1896, there was concern over the pos-
About 1894 headquar-
ters and laboratories of the Illinois State Laboratory of Natural History and of the State Ento-
mologist were moved into this building. From July 1,
1917, until the middle of 1940 it housed
the main offices and most of the laboratories of the Illinois Natural History Survey.
high standards, even though they came
from widely different backgrounds and
possessed widely different trainings.
(Among the sources of biographical
material on Forbes are Anon. 1930, E. B.
Forbes 1930, Ward 1930, Howard 1932,
Van Cleave 1930, 1947, and Marshall
1956.)
Reorganization
Forbes administered the State Labora-
tory of Natural History and the State
Entomologist’s Office as a unit, inter-
changing personnel and materials. Fur-
ther, he made these agencies available to
the University of Illinois in many ways,
and considerable publishing was done in
sible spread of other pests into the state.
In 1899 legislation was passed giving the
State Entomologist large powers in in-
spection, certification, re quarantine.
Other duties were added in 1907.
According to Forbes (1909:55, 66), in
1909 the staffs of the two agencies con-
sisted of the following:
State Laboratory of Natural History
Director
Entomologist
Zoological Assistants
Artist
Secretary
Special assistants from time to time
State Entomologist’s Office
1 State Entomologist
Ree POR
98 InLInoIs NATURAL
10 Assistants
1 Draftsman
1 Chief Inspector
4 Temporary Inspectors
1 Foreman
12 Laborers
Forbes’ interest was primarily in re-
search and not in administering laws.
During the reorganization of state gov-
ernment under Governor Frank O. Low-
den’s administration, the chance came to
make changes which would bring Forbes’
interests into clearer focus. ‘Lhe State
Laboratory of Natural History and the
research activities of the State Entomolo-
History SURVEY BULLETIN
Vol. 27, Art. 2
gist were brought together in 1917 under
a new name, the Natural History Sur-
vey. This Survey was placed in the De-
partment of Registration and Education
along with the two other scientific sur-
veys, Geological and Water. The admin-
istration of quarantine laws and the like
was transferred to the State Department
of Agriculture.
NATURAL HISTORY SURVEY
We have followed the meanderings of
organization from the Illinois Natural
History Society of 1858 through the So-
Theodore Henry Frison, Acting Chief, 1930-1931, Chief, 1931-1945, Illinois Natural His-
tory Survey.
December, 1958 Mitts:
ciety s Museum to the Illinois State Lab-
oratory of Natural History. We have
also discussed the development of the
State Entomologist’s Office from 1867
and have seen this office united with the
State Laboratory in their research duties
to form the State Natural History Sur-
vey in 1917.
A new type of administrative responsi-
bility was set up in the Civil Administra-
tive Code of 1917, which has remained
essentially unchanged to the present time.
The Code (Illinois General Assembly
1917:34) stated that:
Unless otherwise provided by law, the func-
tions and duties formerly exercised by the
State entomologist, the State laboratory of
natural history, the State water survey and
the State geological survey and vested by this
Act in the department of registration and
education, shall continue to be exercised at
the University of Illinois in buildings and
places provided by the trustees thereof.
Within the Department of Registra-
tion and Education was established a
Board of Natural Resources and Conser-
vation; this Board is the responsible agent
for the activities of the Natural History,
Geological, and Water Surveys. The
charge (Illinois General Assembly
1917:34) under which this group has
worked through the years has been to
1. Consider and decide all matters pertain-
ing to natural history, geology, water and
water resources, forestry, and allied research,
investigational and scientific work;
2. Select and appoint, without reference to
the State civil service law, members of the
scientific staff, prosecuting such research, in-
vestigational and scientific work;
3. Co-operate with the University of IlIli-
nois in the use of scientific staff and
equipment;
4. Co-operate with the various depart-
ments in research, investigational and scien-
tific work useful in the prosecution of the
work in any department.
The Board consists of the Director of
the Department of Registration and Edu-
cation, who is chairman, the President of
the University of Illinois or his repre-
sentative, the President of Southern [Ili-
nois University or his representative, a
of whom are ex officio members, and,
addition, experts in the fields of Doren,
biology, ieee forestry, and engineer-
ing who must have had a minimum of 10
years of experience in their professions.
Expert members are appointed by the
From 1858 to 1958 99
Governor and they have traditionally held
long appointments. The biological scien-
tists who have given or are giving of their
time in this important state activity were
or are William Trelease, John M. Coul-
ter, Henry Cowles, Ezra J. Kraus, Carl
G. Hartman, Lewis H. Tiffany, and Al-
fred E. Emerson.
The present Board consists of Director
Vera M. Binks, Dean William L. Everitt
(the representative of President David D.
Henry of the University of Illinois),
President Delyte W. Morris of Southern
Illinois University, Dr. Walter H. New-
house, Dr. Roger Adams, Mr. Robert H.
Anderson, Dr. Lewis H. Tiffany, and
Dr. Alfred E. Emerson.
The Board meets quarterly, receives
reports from the Chiefs, counsels with
them on their research programs, appoints
their scientists, and examines and approves
their budgets.
To return now to 1917: When the re-
organization took place, Forbes, who was
Director of the State Laboratory of Nat-
ural History and State Entomologist,
was retained as Chief of the Natural His-
tory Survey. He remained as Chief until
his death in 1930, and was extremely
alert mentally uncil 9 days before his
death.
Not long after the turn of the century,
Dr. J. W. Folsom of the University of
Illinois Department of Entomology was
walking down a street in Urbana when
he discovered a youngster who was en-
grossed in observing a colony of ants.
Folsom engaged the boy in conversation
and was impressed with his interest and
knowledge. Thus began a close and per-
sonal relationship between Dr. Folsom
and young Theodore Henry Frison.
Frison was born in Champaign, IIli-
nois, on January 17, 1895, and was edu-
cated in the schools of that city. Through
Dr. Folsom he became acquainted with
Dr. Forbes, and these two scientists al-
lowed the boy to attend University
courses prior to high school graduation
(Campbell 1946). Frison was in the army
for a short time in 1918, after which he
returned to the University, which award-
ed him all of his degrees. After short pro-
fessional appointments in Wisconsin and
New Jersey, and upon receiving his Ph.D.
degree, he joined the staff of the Natural
100 Ittino1is NarurAL History SurvEY BULLETIN
History Survey as Systematic Entomolo-
gist. This was in 1923. Upon Forbes’
death in 1930, Frison was made Acting
Chief, and on July 1, 1931, he was ap-
pointed Chief.
Frison was an indefatigable worker,
becoming a_ specialist in bumble bees,
Vol. 27, Art. 2
concluded that it would be essential that
they attempt to obtain funds for a sepa-
rate building. In this attempt they were
successful. The University assigned an
area for the building, and in 1940 the
two Surveys began the move into a new
Natural
Resources Building, built for
Leo Roy Tehon, Acting Chief, Illinois Natural History Survey, 1945-1947.
aphids, and stoneflies. His tenure as Chief
was marked by growth in staff and facili-
ties. In the 1930’s the growth of his or-
ganization was such that it was difficult
to find space for the personnel in the
rooms which the University could devote
to use of the Natural History Survey.
Dr. Frison and Dr. M. M. Leighton,
Chief of the Illinois Geological Survey,
conferred on the problems of space and
their occupancy. The building, and subse-
quent wings which were completed in
1950, were given to the University and
added to that organization’s inventory.
For the first time, the Natural History
Survey had a home which it could really
call its own.
Frison had wide interests, and immedi-
ately upon becoming Chief he began the
development of wildlife research. “This
a
December, 1958 MILs:
field, as a separate discipline, was new.
He was instrumental in organizing the
Midwest Wildlife Conference, the initial
meeting of which was held in Urbana in
1935. Also he was a charter member of
the Wildlife Society.
The staff of the Natural History Sur-
vey increased from 16 in 1930 to 38 at
the beginning of World War II.
In intellect and aggressive enthusiasm,
Frison was a worthy successor of Forbes.
He made many contributions to knowl-
edge. He was a member of many learned
societies and was given positions of re-
sponsibility in them. Beyond that, he was
a golf and tennis player, a fine violinist,
and had a great interest in art, history,
and current affairs.
It was a loss to the Natural History
Survey, and to science, when he passed
away December 9, 1945, after 15 profit-
able years as Chief.
On December 10, 1945, Dr. Leo R.
Tehon was appointed Acting Chief, a
position which he held until February 28,
1947. Tehon was a meticulous scholar.
He was not only a fine plant pathologist
and mycologist, but also a good linguist
and musician (Carter 1955, Ayars 1956).
On March 1, 1947, Dr. Harlow B.
Mills, the present incumbent, took over
the duties of Chief.
THE FUTURE
Throughout its century of existence,
this organization has attempted to meet
the needs of the economy of Illinois with
an eye to the state’s future requirements.
The Board has appointed scientists with
broad views and excellent training, men
who were not satisfied with the present
but who had a strong interest in the
future. A half century. ago Forbes
(1907c:892) wrote, “I shall be governed
by the reflection that we are to-day look-
ing forward and not back—that we are
preparing for the future and not studying
the past— ...” The same fresh view
should govern us at the end of*100 years.
The problems in nature are ever chang-
ing, or, rather, our needs from and ap-
proach to nature are ever changing. There
are new demands and new approaches.
New research techniques require re-eval-
uation of what has been done. In agricul-
From 1858 to 1958 101
ture there are new crops and new meth-
ods of raising them. New plant diseases
appear. New insect pests invade the state.
New demands are made for recreation.
New advances in pure scientific knowl-
edge must be made. All of these demands
and approaches require the attention of
the research specialist. All are inextri-
cably bound up in the future. A scientist
who looks only to the past is professionally
dead.
Perhaps the greatest challenge of the
future lies in the indisputable fact that
human populations in the world — and
that includes Illinois— are increasing.
The demands which these people make on
their environment are increasing more
rapidly than are the people themselves!
For most of our food and living room we
are dependent on that surface which
marks the boundary between the earth
and the atmosphere, on that surface upon
which the sun’s rays strike. We are de-
pendent on it for our food and for our
relaxation. More people mean greater
food demand and greater need for remov-
ing ourselves periodically from the intri-
cacies of a complex civilization. More peo-
ple mean a reduction in space for both
of these necessities. This is the dilemma
of the future. As the years roll by and
the population statistics pile up, our de-
pendence for existence on our living re-
sources constantly becomes greater, and
our dependence on the research scientist
in fields of interest to the Natural His-
tory Survey becomes a complete necessity.
Now, in 1958, we are concerned about
the great strides made by the physical
sciences. These advances have great po-
tential for good and tremendous potential
for human destruction. International
scientific competition has raised its head.
If the deleterious side of this physical
science development is kept in check, we
can be sure that the need for sustaining
humanity, both physically and spiritually,
will be colossal in the years ahead.
We hear in 1958 of “crash programs”’
to develop in the shortest possible time
certain phases of physical science applica-
tion. When the collective human popula-
tion of the United States has to tighten
its collective belt just one small notch,
we will hear of a “crash program” the
like of which has not as yet even been
102
Intinors NaturAt History SuRVEY BULLETIN
Vol. 27, Art. 2
Harlow Burgess Mills, Chief, Illinois Natural History Survey, 1947 to date.
conceived. And when that time comes,
the Natural History Survey will be called
on for even greater activity.
In closing this discussion, it would be
well to call attention to a House Joint
Resolution introduced in the Seventieth
General Assembly of the State of Illinois
by Representatives Ora Dillavou, Charles
Clabaugh, and Leo Pfeffer (Illinois
House of Representatives 1957). The
Resolution reads as follows:
WuerREAS, On June 30, 1858, a group of
far-sighted citizens of this State met at
Bloomington and organized the Illinois State
Natural History Society which was incorpo-
rated in 1861 by an Act of the legislature;
and
WHEREAS, In 1877 the name of the so-
ciety was changed to the State Laboratory of
Natural History, and in 1885 the laboratory
was moved to Urbana where it was placed
under the direction of the Board of Trustees
of the University of Illinois; and
Whereas, The State Laboratory of Nat-
ural History and the research activities of
the State Entomologist’s office were united in
1917 to form the State Natural History Sur-
vey Division of the Department of Registra-
tion and Education; and
Wuereas, The Natural History Survey
has rendered outstanding service in the field
of natural history, especially in regard to
the control of noxious insects, the control of
CE ee ee
December, 1958 MILts:
diseases attacking floricultural and ornamen-
tal plants, the development of forestry in
Illinois, the management of fishes in ponds
and streams, the foods and movement of
waterfowl in this State, the problems of up-
land game species, and the periodic report
of species which are especially endangered,
such as the prairie chicken and wood duck;
and
Wuereas, The following world recog-
nized scientists and scholars have been as-
sociated with the wonderful work of the
Natural History Survey: Stephen A. Forbes,
Robert E. Richardson, David S. Jordan,
| Frank C. Baker, Charles A. Kofoid, Robert
Ridgway,
Benjamin D. Walsh, Wesley P.
Flint, Victor E. Shelford, Theodore H.
Frison, and Leo R. Tehon; and
WHEREAS, Since 1858 the Natural His-
tory Survey has received wide recognition
for its contributions to society, has gained the
respect of scientists throughout the world, has
brought considerable prestige to this State,
From 1858 ro 1958
103
and, above all, has contributed immeasurably
to the welfare of all the people of this State;
and
Wuereas, The 100th anniversary of the
Natural History Survey will be celebrated in
1958; therefore, be it
Resolved, By the House of Representatives
of the Seventieth General Assembly of the
State of Illinois, the Senate concurring herein,
that this General Assembly, on behalf of all
the people of this State, extend heartiest con-
gratulations and sincere appreciation to the
staff, members and employees of the State
Natural History Survey Division, on the oc-
casion of their 100th anniversary, for the
outstanding contributions they have made to-
ward the growth and development of this
State; that we extend to them a wish for
continued success and progress in the future,
and that a suitable copy of this preamble
and resolution be forwarded to the chief of
the State Natural History Survey Division,
Mr. Harlow B. Mills.
Economic Entomology :
HEN settlers moved into the I[lli-
nois country, established homesites,
and began to till the virgin soil, they
found that hundreds of species of insects
native to the area readily transferred
their affections from wild plants to culti-
vated crops, at times in hordes sufficient
to destroy the crops completely. It was
inevitable that the Illinois settlers, like
the eastern colonists, had brought certain
pests along with them. The hitch-hiking
pests included the codling moth in apple
barrels, the hessian fly in straw used as
packing material, bedbugs in bedding, and
lice on the bodies of the settlers. As if
these were not enough, other migrants,
such as the Colorado potato beetle, the
imported cabbage butterfly, the cotton
leafworm, the San Jose scale, the Nor-
way rat, and the fleas thereon, invaded
the area. They were followed in later
years by such notorious insect pests as the
oriental fruit moth, the European corn
borer, the sweet clover weevil, the Mexi-
can bean beetle, and the Japanese hee-
tle.
The early Illinois settlers were a hardy,
self-sufficient, and determined lot, gener-
ally not rich but for the most part thrifty
and aggressive. They took pride in the
fact that they were skilled in the agricul-
tural arts of their day. At the same time,
they admitted that the problem of coping
with the many insect pests that damaged
their crops, annoyed their livestock, and in-
vaded their homes was beyond their com-
prehension. They sought the aid of neigh-
bors, school teachers, doctors, and local
amateur naturalists, who in turn sought
the counsel and advice of Fitch, Harris,
and other entomologists located in the
far-off New England and Atlantic coastal
states. When these sources of informa-
tion proved inadequate, the settlers ap-
pealed to the state legislature to appro-
priate funds and to appoint a state ento-
mologist to study what appeared to be
the most perplexing of all their problems.
On February 27, 1867, the Illinois Gen-
GEORGE C. DECKER®
4)
eral Assembly created the office of State
Entomologist.
EARLY HISTORY E
Pleasant surprises await the curious —
who attempt to assay the extent and use-_
fulness of man’s knowledge of insects
their habits, and control measures in the
1850’s and 1860’s. It is gratifying to note
that local, self-trained entomologists such —
as Walsh, Le Baron, Thomas, Shimer, —
and Riley had collected and identified :
hundreds of species and that they possessed —
a remarkable knowledge of the life cycle
and ecology of perhaps three-fourths of —
the economic species ordinarily included in —
any current list of noxious insects in the
Midwest. Le Baron (1871:5-6) sum-
marized the situation as he saw it at that
time:
:
The history of many of our noxious insects,
and especially the most notorious of them, has
been pretty thoroughly traced, not only by the
entomologists expressly employed by several of
the States for this purpose, but also by many —
other active gleaners in this field. Still, any —
one who enters upon the study of this extensive —
subject, soon finds work enough upon his
hands. It cannot be said that the history of any
insect is perfectly and absolutely known, and
it is a notorious fact that some of the insects
which have been longest known and studied,
such as the Plum Curculio and the Apple
Worm, are the very ones which are causing
the most damage to the horticulturist at the
present day; and if we take into account the
multitude of insects which are preying upon
our shade and ornamental trees and shrubs,
which, in the estimation of many, are scarcely
inferior in value to the fruit bearing trees, we
may safely conclude that the prospect is very
remote when the work of the practical ento-
mologist will cease or materially diminish.
And the force of this view is greatly enhanced
by the [occurrence], every year, to a greater
or less extent, of new species of noxious in-
sects, or rather of insects which, having ex-
isted here or elsewhere in moderate numbers,
from time immemorial, have suddenly sprung
into destructive profusion in consequence of an
abundant supply of congenial food, or the ab-
sence of their natural enemies, or other condi-
tions favorable to life, some of which are
known, and some of which are obscure or in-
[ 104 ]
December, 1958
:
:
:
|
:
:
DECKER:
scrutable. The Colorado Potato-beetle, the
Currant Saw-fly, the Asparagus-beetle, and the
Bruchus granarius; to which we might add
the Pear-caterpillar (Callimorpha Lecontei),
and the Lesser Apple-leaf folder (Tortrix
malivorana,) treated of in the following re-
port, were all unknown here as noxious in-
sects until within the last few years. It is true
that some noxious insects, on the other hand,
have greatly diminished, and some, which have
been the sorest scourges of the orchardist, such
for example, as the notorious Bark-louse of the
apple tree, seem to be in the process of ex-
tinction.
Walsh and the others acquired much
of their knowledge through their own ob-
servations and experience, but obviously
they were familiar with most of the world
literature on the subject. Furthermore,
it seems reasonably certain that then, as
now, much unpublished knowledge on the
subject was transmitted from individual
to individual through correspondence and
conversation, some of it even as tradition.
We know that pioneer naturalists ob-
tained considerable information from the
Indians. For example, the English ex-
plorer, Jonathan Carver (1778:493-4)
wrote of his travels among the American
Indians in 1766:
I must not omit that the LOCUST [grasshop-
per] is a septennial insect, as they are only
seen, a small number of stragglers excepted,
every seven years, when they infest these parts
and the interior colonies in large swarms, and
do a great deal of mischief.
One may be more than a little sur-
prised to discover that several local ama-
teur naturalists—doctors, lawyers, college
professors, orchardists, and agricultural-
ists, never referred to as or considered to
be entomologists—knew many of the
common insects by name and possessed a
knowledge of their biology and_ habits
adequate to permit these men to engage
in lengthy and intelligent discussions on
the subject at meetings of agricultural
and horticultural societies. For example,
Dr. E. G. Mygatt (1855), a physician,
wrote an essay, “Bark Louse of the Apple
Tree,” for the first Transactions of the
Illinois State Agricultural Society, 1853-
- 54, and J. B. Turner (1859), a professor
of Latin and Greek, presented a paper,
“Microscopic Insects,” at the first meet-
ing of the Illinois Natural History Soci-
ety in 1858. It is interesting to note that
at this time two men, Le Baron (1855)
Economic ENTOMOLOGY
105
and Thomas (1859a), each one later ap-
pointed to the office of State Entomolo-
gist, were presenting papers on Illinois
birds and other topics in the field of nat-
ural history.
In the light of these pleasant surprises,
one is amazed to realize that the com-
bined knowledge of all the experts was
almost nil when it came to questions of
practical control measures that could be
employed to eliminate these pests or even
to reduce materially the annual losses
attributable to them. It is possible that
the paucity of practical information can
best be understood if we recall that for
many years it was believed well-nigh sac-
rilegious for a scientist to consider the
practical application of his accumulated
knowledge; as the distinguished Professor
Louis Agassiz (1863:24) once said, “the
man of science who follows his studies
into their practical application is false to
his calling.”
Local and national repudiation of this
philosophy contributed to the industrial
and agrarian crusades that resulted in
creation of state entomologists’ offices
and land grant colleges. Touching upon
the new philosophy of science and educa-
tion in addressing the founders of the
Illinois Natural History Society at their
first meeting in 1858, Turner (1859:
647) said:
In respect, also, to those grosser forms of
vegetable and animal life, it seems to me that
our research should in future aim more di-
rectly at practical utility than in the past.
We are quite too content with mere descrip-
tion of forms and names, sometimes, without
pushing our inquiries into the causes, relations
and uses, and evils of things.
We need not simply to christen ‘all these
things—not simply to name the beasts, but also
to rule over them, as did our great father
Adam; and, also, all other forms of matter.
And we cannot do this till we know minutely
their history, habits and relations to other
things and beings.
The grand end to be aimed at, in reference
to most forms of fungi and parasites of all
sorts, is their prevention or destruction. But
a vast amount of minute antecedent knowledge
is needed before we can hope to say, “thus far
and no farther,’ even to one single race or
tribe, much more to the vast myriad of races
and tribes.
Benjamin Walsh, the first State Ento-
mologist of Illinois, was in full accord
with the views of Turner. In addressing
106
a meeting at Cobden, Illinois, in No-
vember, 1867, he said:
I do not regret to say that I belong to the
modern school of science, and think it no deg-
radation, so far as my specialty is concerned,
to bring science to the aid of practical men in
the related departments of human industry.
And I need not tell you, for you know, that
insects pick your pockets, and that to fight them
successfully it is necessary to know their habits
and how to distinguish friends from foes
(Walsh 1868a:143).
Cyrus Thomas subscribed to the new
philosophy several years before he became
State Entomologist.
And the study of natural history is a useful
study, having many direct practical advan-
tages. Agriculture is the pedestal on which the
stately fortunes of bankers and merchant kings
are reared, and as the pedestal contracts or
expands, so rises or falls the lofty column
(Thomas 1859a:667).
Therefore, we say, that natural history
should be studied for the practical use made
of the knowledge obtained. And, if it be a
study so desirable and so useful, the question
arises, Should not the study be generally intro-
duced into our schools and colleges?
I answer, most emphatically, yes! There is
no other branch of physics, nor any branch of
metaphysics so important and so necessary to
be studied in the school room as natural his-
tory. And I am glad to see that quite a num-
ber of institutions have ventured to cross the
Rubicon; yet others are halting at the brink,
fearful of the result (Thomas 1859a:668).
Thus, the first and third State Ento-
mologists publicly expressed their views.
They took office dedicated to the task of
assisting the residents of the state of IIli-
nois to find practical solutions for their
numerous and complex entomological
problems. Their successors followed the
same course.
PRACTICAL PROBLEMS AND
PROGRESS
Change is eternal in the insect world;
thus, it appears that the need for contin-
ued study of insects will never end. This
situation may be confusing to laymen, but
entomologists and others who have closely
studied nature realize that insects are
dynamic creatures subject to constant
change in characteristics. Because of
their great mutability, insects have sur-
vived in an ever-changing world for mil-
lions of years and are still capable of
ILtLINois NatrurAL History SuRVEY BULLETIN
making the necessary adjustments to
many of the important changes in their —
environment. Most of the important eco- —
logical changes in an area or community
are accompanied by changes in the insect
fauna; some species drop out and others
move in.
Every agricultural practice adopted or
discarded by man induces a significant en-
vironmental change or modification which
will favorably or unfavorably affect in-
sects and, for that matter, all other living
organisms in the area involved. Changes
in crop rotations, fertilization practices,
pruning, or drainage will prove favorable
for some species and unfavorable for oth-
ers.
At the time the Office of State Ento-
mologist was established in Illinois, fruit
and vegetable crops could not be econom-
ically produced and marketed in the state
without reasonably effective insect con-
trol. Since the high per acre value of such
crops seemed to warrant expenditures for
insect control, Illinois producers of these
crops demanded and received a_ large
share of the Entomologist’s time. As the
nature and magnitude of insect losses in
other agricultural and nonagricultural
areas became more apparent and better
understood, pressures from a multitude of
other sources necessitated a realignment
and much greater diversification of ento-
mological research.
Space will not permit enumeration and
full discussion of all the insect problems
that have arisen to plague Illinois farm-
ers in the past century and it will not
allow a detailed review of the thousands
of printed pages that have been used to
record the findings of research conducted
during this period. Therefore, in the
brief resumé that follows we confine our
attention to a few specific examples.
Fruit Insects
In 1868 an editor of The American
Entomologist, probably Walsh, sum-
marized the fruit insect situation as fol-
lows: :
It is notorious among fruit growers, that the
Curculio has now almost entirely vetoed the
cultivation of the plum; and of late years this
pernicious little Snout-beetle has extended its
ravages to the peach, and even to the apple
and pear, to say nothing of those rarer and
Vol. 27; Arta y
.
fs
“a
i |
e
3
a
December, 1958 DECKER:
choicer fruits, the nectarine and the apricot.
The strawberry and the grape vine are in-
fested by a host of insects, some of them known
for many years back to science, others de-
scribed and illustrated for the first time by the
editors of this paper in various publications;
while there are still others the natural history
of which has never yet been published to the
world, and which will be figured and described
by the editors in the progress of this work.
What with the Bark-louse in the North, the
Apple-root Plant-louse in the South and the
Apple-worm everywhere, the apple crop in
North America is gradually becoming almost
as uncertain and precarious as the plum crop
(Walsh & Riley 1868a:1).
To show that the testimony of an ento-
mologist was not biased and that the con-
ditions described above were more or less
general, we may note a comment made by
the eminent journalist Horace Greeley
(1870:301):
If I were to estimate the average loss per an-
num of the farmers of this country from insects
at $100,000,000, I should doubtless be far be-
low the mark. The loss of fruit alone by the
devastations of insects, within a radius of
fifty miles from this city, must amount in value
to millions. .. . We must fight our paltry ad-
versaries more efhciently, or allow them to
drive us wholly from the field.
The first white settlers in Illinois ob-
served that the native fruits—plums,
grapes, haws, and berries—were subject
to attack by a variety of insects. More
than three-fourths of the species recog-
nized as fruit pests today were recognized
and mentioned in agricultural or hert:-
cultural reports and farm journals prior
to 1870. The plum curculio, for exam-
ple, was to be found in every plum thicket
and, when improved varieties of plums
were introduced, the curculio took to
them like ducks to water. In discussing
plum culture at a fruit growers’ meeting
in 1852, a Mr. Brewster reported that
for + years the curculio had destroyed his
plum crop. Then followed a general dis-
cussion of proposed control measures,
such as jarring, banding, paving, and
using lime, soap suds, and chamber lye.
The following year a similar report pro-
voked a repetition of the members’ favor-
ite control measures, but by then two gen-
_tlemen had the answer: Just fence the
plum orchard and turn in_ chickens
(J. A. Kennicott 1855:296, 314-5).
The idea of using chickens for control
of curculio paralleled a suggestion made
Economic ENTOMOLOGY
107
by a Mr. Harkness at a _ horticultural
meeting in 1853:
Some twelve years since, a neighbor of his en-
closed a wild plum thicket, as a yard for
swine; trees bore full crops every year; never
troubled by curculio, whilst other thickets
about had fruit nearly all destroyed by them.
Four years since the hogs were turned out, and
the ground appropriated to other uses; the
first year after, the fruit was mostly destroyed
by curculio (J. A. Kennicott 1855:314).
Gradually certain members of the cur-
culio tribe developed a liking for related
stone fruits and even apples. In his first
and only report as State Entomologist,
Walsh (18684:64) noted:
Although the Curculio now infests the culti-
vated species of Plum (Prunus domestica, Lin-
naeus,) to fully as great an extent as our com-
mon wild species (Prunus americana,) yet it
is only at a comparatively recent date that it
attacked our cultivated Plums, and since that
epoch it has been growing every year worse
and worse, and making onslaughts upon other
fruits, such as the Peach, the Cherry, and even
the Apple.
For 20 to 30 years the use of Hull’s
curculio catcher or similar devices to jar
curculios out of infested trees, so that the
insects could be destroyed, and the use of
hogs and chickens confined to the or-
chards to consume infested fruits as they
fell were the two principal, and perhaps
the only meritorious, control measures.
One should note, however, that farm
journals carried glowing advertisements
for numerous concoctions, which were
almost worthless or which did more harm
than good.
The successful use of insecticides for
the control of the plum curculio on peach
and other stone fruits did not materialize
until lead arsenate came into the picture
in the late 1890’s, because the more solu-
ble arsenic compounds—white arsenic,
Paris green, and London purple—then
available proved too phytotoxic for use on
such delicate foliage as that of peach,
plum, and cherry. With the aid of im-
proved insecticide formulations, spray
schedules, and equipment developed
through years of continued research, IIli-
nois orchardists were able to hold their
own with the curculio until a crisis de-
veloped during World War II. Then as
labor and other overhead costs increased
and lead arsenate became less effective,
108
many peach growers, after a few years in
the red, pulled up their trees and aban-
doned production. A hope that DDT
would control plum curculio faded quick-
ly, but BHC became available just in
time to save the peach-growing industry.
BHC was short-lived as an _ insecticide
for plum curculio control; it was replaced
by more effective and less objectionable
materials such as chlordane, dieldrin, and
parathion. However, it was BHC that
saved the day for a number of orchardists.
Orchards that could have been bought for
a song, and a poor one at that, in the fall
of 1946 and spring of 1947 were not for
sale in 1948.
After a century of research by the Nat-
ural History Survey and its parent or-
ganizations, we find the plum curculio is,
for the moment at least, very well under
control. Surveys conducted in 32 com-
mercial peach orchards for the past 5 years
showed that at harvest time less than 1
per cent of the fruit was infested or dam-
aged by this weevil.
Other insects of the peach that have
required research attention include the
oriental fruit moth, a group of sucking
insects responsible for an injury known
as catfacing, the peach tree borers, and at
least three species of scale insects. For-
tunately these, too, are successfully con-
trolled by currently available measures.
Even so, peach growers insist that the
entomologist will have to find more eco-
nomical control measures, or the high cost
of producing peaches will put the growers
out of business.
The codling moth (mentioned by
Walsh as the “Apple-worm’’), unques-
tionably the No. 1 apple insect in Illinois,
apparently arrived in eastern United
States from Europe about 1800 and made
its first appearance in Illinois about 1850.
In 1869, while checking his theory that
this insect had been a hitch-hiker in apple
barrels, Walsh reportedly found about
200 cocoons in a single barrel. The cod-
ling moth wasted no time in becoming
adapted to its new environment. In the
early transactions of the horticultural and
agricultural societies and in pioneer farm
journals, there are numerous references to
the ravages of this insect. For example, in
the first issue of The American Entomol-
ogist in September, 1868, we read:
[Ltinors NaturAL History SurvEY BULLETIN
Vol. 27, Art. 2
i
a
<
&
Jotham Bradbury, residing near Quincy, IIL.
has an old apple orchard, which many years
ago used invariably to produce nothing but
wormy and gnarly fruit. A few years ago he
plowed up this orchard and seeded it to clover,
by way of hog pasture. As soon as the clover
had got a sufficient start, he turned in a gang
of hogs, and has allowed them the range of his
orchard ever since. Two years after the land
was plowed the apple trees produced a good
crop of fair, smooth fruit, and have continued
to bear well ever since (Walsh & Riley
1868b:455).
In the same article, further extolling ©
the value of hogs, we read:
But the plum curculio and its allies are not
the only insects that we can successfully attack
through the instrumentality of the hog; neither
is stone fruit the only crop that can be pro-
tected in this manner. For the last fifteen
years or so, pip fruit, namely, apples, pears,
and quinces, have been annually more or less
deteriorated by the apple worm or larva of the
codling moth boring into their cores, and filling
their flesh with its loathsome excrement
(Walsh & Riley 1868):3).
In addressing the Southern Illinois
Fruit Growers Association in 1867, Pres-
ident Parker Earle (1868:137) said:
The curculio and the tree borers have been
discussed at length in our former meetings, but
the codling moth—which threatens us even
greater damage than the curculio—has re-
ceived little attention. There is some hope that
great promptness and energy may save us from
the terrible devastation which this moth has
wrought in all the older States, and in the
older fruit-growing neighborhoods of Illinois.
Its damage to the apple crop of the country
each passing year should be reckoned at mil-
lions of dollars. From all sections we have the
same sad story of “the apples dropping prema-
turely’—“the apples mostly wormy”’—“the ap-
ple crop used up,” by the codling worm.
In many districts of the East where apples
were once abundant they now entirely fail,
because of the worms, and they not only
threaten the destruction of the apple crop of
the country, the whole country, but pears seem
equally exposed. In many sections of the West
nine-tenths of the pears are reported spoiled
by the codling moth.
The comments of Earle and other early
horticultural leaders clearly establish the
codling moth as the outstanding pest of
apples in Illinois in the third quarter of
the nineteenth century. From 1850 to
1870 the pasturing of hogs in the or-
chards and the use of straw or cloth bands
around the tree trunks to trap larvae for
later destruction were about the only con-
trol measures of established merit. Even
December, 1958 DECKER:
these measures were only partially effec-
tive, and a large percentage of the apples
harvested showed insect damage. In fact,
the situation was so bad that the fruit
judges at county fairs protested the ad-
mission of fruit damaged by codling moth,
and eventually a rule was passed that the
unmistakable evidence of codling moth
damage or the presence of San Jose scale
disqualified a fruit for competition. In-
secticides did not come into the picture
until after the value of Paris green had
been established for the control of the
Colorado potato beetle and a number of
other pests.
In his third report as State Entomolo-
gist, Le Baron (1873:17Z) recommended
only cultural practices for control of the
codling moth: .
PRACTICAL TREATMENT.
This may be reduced to the four following
heads:
Ist. Destroying the insects in their winter
quarters.
2d. Picking the
trees.
3d. Gathering the wormy apples from the
ground, or letting swine and sheep have the
range of the orchard.
4th. Entrapping the worms in bands and
other contrivances.
To which may be added the help to be de-
rived from their natural enemies.
In his previous report, Le Baron
(1872:116) had mentioned the use of
Paris green to control cankerworms on
apple, and this may in part have led to
the subsequent work by Forbes and oth-
ers for control of codling moth on apple.
We find but few references to trials
with Paris green on crops in 1867 and the
following decade. In 1880, however, with
repeated warnings that suitable precau-
tions must be observed, large-scale testing
of Paris green and its companion, London
purple, got under way. After 2 years
(1885-1886) of experimentation, Forbes
(1889:15) concluded:
The experiments above described seem to
me to prove that at least seventy per cent of
the loss commonly suffered by the fruit grower
from the ravages of the codling moth or apple
worm may be prevented at a nominal expense,
or, practically, in the long run, at no expense
at all, by thoroughly applying Paris green in a
spray with water, once or twice in early
spring, as soon as the fruit is fairly set, and
not so late as the time when the growing
apple turns downward on the stem.
wormy apples from the
Economic ENTOMOLOGY
109
He presented data showing that, in
1885, 68 per cent of the unsprayed apples
were wormy, whereas only 21 per cent of
the sprayed apples were wormy, and, in
1886, 40 per cent of the unsprayed apples
were wormy and 12 per cent of the sprayed
fruit. When lead arsenate became avail-
able about 1895, entomologists began ex-
perimenting with it, and for the next 30
to 40 years practically all codling moth
research centered around attempts to
improve formulations and spray _ sched-
ules involving the use of this chemical.
Between 1915 and 1918, in seven sep-
arate studies, Illinois entomologists found
that in unsprayed blocks fruit ranged
from 9 to 84 per cent wormy and aver-
aged 45 per cent wormy, whereas in the
blocks sprayed with improved lead arse-
nate formulations the fruit ranged from
1 to 20 per cent wormy and averaged 4.4
per cent wormy.
With what appeared to be a satisfac-
tory control measure working reasonably
well year after year, entomologists and
fruit growers alike became more or less
complacent, only to be shocked by a dou-
ble-barrelled attack. The codling moth
began to show evidences of resistance to
arsenical sprays, and, as dosage rates and
numbers of applications were increased,
the United States Food and Drug Ad-
ministration began to bear down on lead
and arsenic tolerances. The next three
decades might be characterized as a pe-
riod of mad scramble for cover. Attempts
were made to find (1) ways to remove
spray residues, (2) suitable substitute
materials, (3) ways to synergize insecti-
cidal action without increasing residues,
and (4) better sanitation and other non-
chemical procedures. Research did well
to hold its own, during this critical pe-
riod, until DDT came into the picture at
the close of World War II. The success
of DDT in controlling the codling moth
was spectacular, and within 2 years the
growers’ clamor for more work on codling
moth control faded.
A review of research data and the re-
sults of harvest surveys made the past 3
years show that now 33 to 94 per cent of
the fruit in unsprayed apple orchards is
wormy, approximately the same percent-
ages as in the 1860’s, 1880’s, and the sec-
ond decade of the present century. In
110 I~ttinois NarurAL History SURVEY BULLETIN
contrast, we find that in sprayed orchards
0.03 to 7.6 per cent, or an average of 2.2
per cent, of the fruit is wormy. Thus, we
find that, in spite of adversities and re-
verses, continued research has developed
control measures that have enabled apple
growers to reduce the percentage of
Vol. 27, Art. 2
a dozen important scale insects alone.
One scale insect of great importance is
the San Jose scale, which was introduced
into California from China about 1880
and into Illinois about 1895. For a time
this scale threatened to wipe out the IIli-
nois commercial fruit industry. Parasites,
Spraying equipment designed and used about 1897 by the State Entomologist and his assist-
ants for experiments on control of San Jose scale. ‘The principal apparatus used is a large and
complicated machine sprayer consisting of a one-horse power gasoline engine, a three-cylinder
force pump, and a large double galvanized-iron tank with a powerful gasoline heater beneath
for making the solution of whale-oil soap” (Forbes 1900:14). The sprayer was mounted on a
two-horse baggage wagon.
worm-damaged apples from possibly 60 to
100 per cent in 1867 to 21 per cent in
1885, 4.4 per cent in 1915, and 2.2 per
cent in 1957.
If it appears that entomologists have
devoted too much attention to this one
insect, let us recall that codling moth re-
search has been the traditional guinea pig
for the study of many insect control pro-
cedures, and that the measures developed
for the control of the codling moth for
the most part have given satisfactory con-
trol of a considerable number of other
pests of apples.
A list of the insects attacking fruit
crops in Illinois would no doubt include
100 or more species. There are at least
predators, and diseases have played an im-
portant role in holding this insect at bay,
but for over 50 years orchardists have
found it necessary to apply a dormant
spray or some other special treatment to
bring this insect under control. As late
as 1950, Illinois apple growers seemed to
agree that if the use of sprays was to be
forbidden San Jose scale would eliminate
commercial orchards within 5 years. This
insect, perhaps more than any other, has
been responsible for the development of a
strong plant inspection and quarantine
system in Illinois, and, for that matter,
in other states as well. Here we have an
insect that can barely survive on wild or
neglected trees but that thrives on young,
=. GS
December, 1958 DECKER:
vigorously growing orchard trees—an ex-
cellent example of how man creates, or at
least aggravates, his own insect problems.
The more man prunes and fertilizes, the
more certain he is to develop a serious San
Jose scale problem.
Truck Crop Pests
An article, probably by Walsh, pub-
lished in 1869 makes it clear that at an
early date a host of insects were recog-
nized as important pests of a wide vari-
ety of vegetable crops:
There is scarcely a vegetable raised in our
gardens that is not preyed upon by one or
more grubs, caterpillars, or maggots, so that,
when we eat it, we have positively no security
that we are not mingling animal with vegeta-
ble food. Two distinct kinds of maggots, pro-
ducing two distinct species of two-winged Fly,
burrow in the bulb of the onion. Scabby po-
tatoes are inhabited by a more elongated
maggot, producing a very different kind of
two-winged Fly, and also by several minute
species of Mites. Turnips, beets, carrots and
parsnips are each attacked by peculiar larvae.
And as to the multifarious varieties of the
cabbage, not only are they often grievously
infested by the Cabbage Plant-louse—a species
which has been introduced from Europe into
this country—but also by an imported cater-
pillar producing a small moth, and by several
indigenous caterpillars producing much larger
moths, some of which caterpillars, when full-
grown, are over one inch long (Walsh & Riley
1869:114).
Why the article failed to include the
corn earworm, the squash vine borer, the
cucumber beetles, and the melon louse is
hard to say, for they were numbered
among the best known pests at the time.
One is amazed that the Colorado potato
beetle was not mentioned, because this
species was the most spectacular insect
pest of vegetable crops in Illinois in the
latter half of the 1860’s. Presumably,
prior to 1850 the Colorado potato beetle
was unknown except as an _ interesting
species found only in the foothills of the
Rocky Mountains, where it fed on a wild
potato somewhat resembling the common
horse nettle. When the pioneers planted
Irish potato and egg plant in Nebraska
and Colorado, the beetle found these
closely related plants to its liking, in-
creased its numbers many fold, and took
off for the East, flying from one settler’s
potato patch to another’s. Here again we
have an example of how man may create
Economic ENTOMOLOGY 111
his own insect control problems. The in-
troduction of a crop highly attractive to a
native insect invites this insect to trans-
fer its affections to the newly introduced
crop. ‘The potato beetle transferred its
affections from its native host to the in-
troduced potato. It seems quite probable
that the potato beetle’s many natural en-
emies did not travel eastward but con-
tinued searching for it in its old haunts.
With an abundance of lush, nutritious
potato vines and a temporary release from
its natural control agencies, the Colorado
potato beetle, in the vernacular of today,
“went to town’ until a new system of
checks and balances could be established.
The eastward movement of the potato
beetle was first noted in eastern Colorado
in 1859. It did not appear in Illinois un-
til 1864. Damaging populations of this
beetle were reported in several Illinois
counties in 1865. Some of the tales of
wholesale potato destruction related in
the local press and the Prairie Farmer
were downright pathetic:
“Let every man and woman in the country or
in town, who has a potato patch, try experi-
ments for the destruction of these pests and
report progress. Something must be done to
stop the destruction of the vines by these in-
satiate creatures or we may as well quit trying
to raise potatoes” (Cedar Valley, Iowa, Times,
quoted by Riley 1866:432).
I know of several cases near Rock Island, IIli-
nois, where the owners of potato-patches, after
persevering in a course of hand-picking for
fully a month, finally gave up in despair, be-
cause as fast as they killed off their own bugs,
a fresh supply from their neighbors’ potato-
patches kept flying in upon them (Walsh
1866:14).
All accounts seem to agree that neither lime,
nor ashes, nor any available external applica-
tion is of the least use in checking the depre-
dations of this insect. The Prairie Farmer says
that “Mr. Jones found, after many experi-
ments, that neither hot lime, lime-water, brine,
tobacco-water, wine (?) nor sulphur had any
effect on them; that turpentine, benzine and
kerosene would kill them when copiously ap-
plied, but also killed the potatoes,’ and that
“coal-oil mixed with water is ineffectual.”
. .. Although there is some contradictory evi-
dence, yet the general result of all the testi-
mony is, that neither domestic fowls, nor ducks,
nor turkeys will eat them, at all events to any
very extensive amount (Walsh 1866:14).
Hand picking, or the manual collection
and destruction of the beetles, their lar-
vae, and their eggs, was about the only
really effective control measure. During
112 [Ltinois NaruraAL History SurvEY BULLETIN
the next several decades, it was said of
many a farm boy who had risen to a
prominent position, “He made his first
dime collecting potato bugs on his grand-
father’s farm’’—not his father’s farm, for
there, in accord with the tradition of the
Vol. 27, Art. 2
The value of predators and parasites
was not overlooked, and at times differ-
ent kinds of poultry, particularly turkeys,
were noted as effective control agents.
Hellebore, London purple, and calcium
arsenate were later added to the list of
Spraying equipment developed in recent years by entomologists of the Illinois Natural
History Survey for the control of the corn earworm and the European corn borer on sweet
corn and field corn.
day, he performed the task without com-
pensation as a member of the family.
Many potato growers experimented
with Paris green applied in several ways,
and by 1870 dusting plants with a mix-
ture of Paris green and flour or lime was
quite generally accepted as the most ef-
fective remedy available. However, there
were many growers who were fearful of
the poisonous properties of the arsenical
compounds and they continued to place
their trust in hand picking. Some grow-
ers went so far as to design rather elab-
orate mechanical devices which they
mounted on skids and dragged up and
down the rows to beat the beetles from
the plants and collect them in pans, trays,
or boxes, where the beetles could be de-
stroyed.
insecticides recommended for control of
the Colorado potato beetle. As the potato
leafhopper, aphids, blight, and other pests
attracted increased attention, a variety of
insecticide and fungicide combinations
came into common use. Research pro-
duced minor improvements in formula-
tions and methods of application that en-
hanced the effectiveness or economy of
control measures, but there was no sub-
stantial or basic change in control pro-
cedures or practices until the advent of
DDT in 1946. While potato growers
and entomologists alike had been inclined
to feel that the control measures in use
in the early 1940’s left little to be de-
sired, they apparently overlooked or gross-
ly underestimated the damage inflicted by
the insects, for within 2 years after
December, 1958 DECKER:
DDT came into general use the per-acre
potato yields practically doubled.
Numerous early reports indicate that
the pioneer cabbage grower had to con-
tend with about the same insects that
plague the cabbage grower of today, but
the pioneer had no arsenal of effective in-
secticides. Lime, lye, and ash mixtures
advocated by some growers were of little
use except in those cases where the plants
were so heavily coated with one of the
mixtures that physical contact between
the insect and the plant was practically
impossible. The scalding water drench
proposed by some persons was at times of
value, but was very apt to damage the
plants. ‘The arsenicals were used spar-
ingly and on small plants only ; they could
not be safely employed on more mature
cabbages. “Thus, for many years the
sound, unblemished head of cabbage was
a rarity, and there was always danger of
consuming protein with the slaw. In fact,
it is very doubtful if any kraut made in
those days could have passed present day
Food and Drug Administration inspec-
tions for insect fragments. There are
those who contend that the prevalence of
scurvy in the armies of the North and the
South during the Civil War was in no
small measure due to the fact that farm-
ers could not produce adequate quantities
of cabbage and related cole crops.
Although some nicotine and pyrethrin
products had been known for many years,
they did not come into practical use until
about 1910. Derris, cubé, and other ro-
tenone preparations made their appear-
ance in the 1920’s. When properly ap-
plied, these insecticides were quite effec-
tive, but they possessed very limited re-
sidual properties and were relatively ex-
pensive. ‘Their acceptance by cabbage
growers was not enthusiastic, and ento-
mologists were under constant pressure
to improve formulations by the use of
synergists or stabilizing agents. “Then
came DDT and the organic phosphate in-
secticides, and it looked for a time as if
the cabbage growers’ insect problems were
effectively solved. But the insects once
again demonstrated their mutability, and
soon cabbage worms were resistant to
DDT. Today the entomologist is worse
off than he was in the early 1940's, be-
cause the cabbage growers, having once
Economic ENTOMOLOGY
13
experienced the fine performance and
economy of DDT in the early 1950’s, are
unwilling to settle for anything less eff-
cient. ‘The currently recommended spray
schedule, which calls for using endrin un-
til cabbage heads begin to form and fin-
ishing with occasional applications of
phosdrin or parathion, is a highly effec-
tive treatment, but the growers remem-
ber equally satisfactory results with the
less complicated use of DDT.
Sweet corn growers in Illinois, like
the cabbage growers, must cope with
an insect problem that requires both a
thorough knowledge of the seasonal ac-
tivities of the pest and a rather meticulous
control treatment. The corn earworm is
a native American pest that has long con-
tested man’s right to the sweet corn pro-
duced in Illinois. Unlike the cabbage
worm, this insect has continued to defy
man’s best efforts to control it. Several
reasonably effective control measures have
been developed, but none has been fully
accepted by Illinois sweet corn growers.
The corn earworm control measure cur-
rently recommended involves precise but
not unreasonable methods of application
and accurate timing of treatments. Some
Illinois sweet corn growers have been un-
able or unwilling to apply the requisite
control measures. When infestations of
the corn earworm are light, mediocre con-
trol practices prove adequate, but, when
infestations are heavy, more meticulous
practices are essential. In parts of Flor-
ida and Texas, where sweet corn growers
cannot afford to gamble on having light
infestations, many growers produce 97 to
99 per cent clean ears of corn by care-
fully following the control measures rec-
ommended by entomologists.
Cereal and Forage Crop Pests
Insect, depredations were by no means
confined to the fruit and vegetable crops
produced by the early settlers in Illinois.
Wheat, corn, and even the native prairie
grasses were subject to attacks that at
times amounted to almost total crop de-
struction. In an article in the first issue
of The American Entomologist, a writer,
presumably Walsh, observed:
Few persons are aware of the enormous
amount of wealth annually abstracted from the
pockets of the cultivators of the soil by those
114
insignificant little creatures, which in popular
parlance are called “bugs,” but which the sci-
entific world chooses to denominate “insects.”
Scarcely a year elapses in which the wheat
crop of several States of the Union is not more
or less completely ruined by the Chinch-bug,
the Hessian Fly, the Wheat Midge, or the
Joint Worm. . . . The White Grub attacks
indiscriminately the timothy in the meadows,
the corn in the plowed field, the young fruit
trees in the nursery, and the strawberry beds
in the garden; always lurking insidiously
under ground, and only making its _pres-
ence known to the impoverished agriculturist _
by the losses which it has already inflicted
upon him. at periodic intervals the
Army-worm marches over their fields like a
destroying pestilence; while in Kansas, Ne-
braska, and Minnesota, and the more westerly
parts of Missouri and Iowa, the Hateful
Grasshopper, in particular seasons, swoops
down with the western breeze in devouring
swarms from the Rocky Mountains, and, like
its close ally, the Locust of Scripture and of
Modern Europe, devours every green thing
from off the face of the earth (Walsh & Riley
1868a:1).
Certainly Walsh was in a position to
know the armyworm problem, because in
1861, 6 years before the creation of the
State Entomologist’s Office, the Rock
Island and Chicago and the Illinois Cen-
tral railroads granted him, as a member
of the Illinois Natural History Society,
passes that permitted him to spend sev-
eral weeks studying a major armyworm
outbreak that developed in central and
southern Illinois. That fall, in typical
Walsh style, he wrote:
. I always hate to give nothing for
something, and having been obliged by the
railroad companies, I endeavored, to the extent
of my poor abilities, to return the obligation,
by seeking a remedy for a little pest, that has
this year destroyed one-fourth part of the tame
hay grown within the limits of the State
(Walsh 1861:350).
This was the introduction to an ex-
tremely interesting and informative 15-
page report on the ecology of the army-
worm and its natural enemies which he
appended to an essay prepared for de-
livery at the annual meeting of the IIli-
nois Agricultural Society. Walsh re-
ported:
When they [armyworms] leave the meadows
in which they originate, they travel on—some-
times as far as half a mile—until they meet
with wheat, rye, oats, corn, sorghum, or Hun-
garian grass (Walsh 1861:351).
Many instances are on record of the great
difficulty with which they have been kept out
Ittinors NarurAL History SurvEY BULLETIN
Vol. 27, Art. 2
of houses which happened to lie in their path
(Walsh 1861:352).
From the Prairie Farmer of July 4, —
the
1861, Walsh (1861:351) quoted
words of ‘an accurate observer’ who
described an infestation of armyworms: —
“As to their number, they have been seen —
moving from one field to another, THREE —
TIERS DEEP. A ditch has been filled with —
them to the depth of THREE INCHES IN
HALF AN HOUR.”
Walsh was fortunate in being able to
acquire, through contacts with a number
of pioneer settlers, valuable notes on his-
toric armyworm outbreaks of the past.
Some of these notes seem worthy of repe- —
tition as an example of the fund of un- |
published entomological history and
knowledge that has passed from one gen-
eration to another:
As we might expect from the laws govern-
ing the development of insect life, the army-
worms make their appearance in noticeable
numbers in different years in different parts
of the State. I have no doubt that they exist in
small numbers in every part of the State from
year to year; for although they have never
appeared till 1861 in the neighborhood of Rock
Island, in such numbers as to attract attention,
yet I myself captured a single specimen of
the army-worm moth in Rock Island county, in
each of three years, 758, ’59 and ’60. At Okaw
they are recorded to have appeared in 1850;
in the south part of Vermilion county, in 1835;
and Mr. Joseph Bragshaw, of Perry county,
says that they visited that county in ’25, ’26,
34 39%
Jonesboro, in Union county, one of the oldest
and most respected citizens of Southern IIli-
nois, informed me that about 1818 or ’20 they
were far more numerous there than in 1861,
and that in 1861 there would not be a single
cock of hay put up in his neighborhood save
one meadow which was part clover and part
timothy, and which I can myself testify was —
”
badly “patchy,” there not being more than an
eighth part of it which would turn out a good
swarth of clover, the timothy being “nil”
throughout. In 1838 again, according to the
Colonel, there were but few of them. In 1842
they were about as in 1861; and in 1856 they
occurred only in small numbers (Walsh 1861:
353).
It certainly is an encouraging sign of the
progress of entomological discovery in this
State, that a noxious insect of primary impor-
tance should have been, for the first time,
traced through all its transformations in the
year 1861 by no less than four citizens of IIli-
nois to my certain knowledge—I refer to Mr.
Cyrus Thomas of Murphysboro, Mr. Emery of
the Prairie Farmer, Col. Dougherty of Jones-
boro, and last and least myself (Walsh 1861:
356).
ROLES IES TDR
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s
ei
-
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Nh te te Matec
41 and ’42. Colonel Dougherty, of %
December, 1958 DECKER:
While many of the observations made
by Walsh and the other gentlemen men-
tioned were sound and are still valid, one
observation was in error and resulted in
a recommendation which, although it had
the desired effect, was based upon a false
premise. Walsh (1861:349) advised,
“Burn your tame grass meadows over
annually, in the dead of the year, and get
your neighbors to do the same, and you
will never more be troubled with the
army worm.’ Walsh thought that the
armyworm passes the winter in the egg
stage, but such is not the case, and there-
fore burning, as he recommended, did not
destroy the eggs. We now know that
when the moths appear in the early spring
they fly at night; in the daytime, they
hide in rank grass, preferably a dense mat
of old, dead grass in a vigorous meadow.
There, in April and May, they lay their
eggs. Thus, while winter burning did
not destroy eggs, it had a profound effect
on the number of worms developing in
burned-over fields and often, if not usu-
ally, prevented serious infestations from
developing.
The recommendation for burning per-
sisted for several years, and by 1880 it was
supplemented by a recommendation for
the use of dusty trench barriers to trap
worms on the march. Spraying strips
with Paris green was proposed by some,
but was generally considered both dan-
gerous and impractical.
The use of poison bait (a mixture of
bran and Paris green) for the control of
armyworms, cutworms, and grasshoppers
came into use about 1885, and with minor
modifications remained the principal and
most practical control measure available
until the advent of the modern chlori-
nated hydrocarbon insecticides. Since
1951, growers have been generally suc-
cessful in controlling armyworms_ by
spraying with such materials as toxaphene,
dieldrin, and endrin. Furthermore, with
the insect outlook and warning service
bulletins available weekly during crop
seasons from the Natural History Survey,
Illinois farmers are now able to control
-armyworms effectively when the worms
are one-fourth to one-half grown. Ap-
plied control measures save the small
grain and the meadow grasses as well as
protect adjacent crops from migrations.
Economic ENTOMOLOGY
Ls
The chinch bug, another infamous pest,
has been well known to Illinois farmers
since 1820. This species, like the army-
worm and many others, is not a serious
pest every year, but tends to be sporadic,
perhaps somewhat cyclic, in its appear-
ance. Weather, of course, is a factor that
influences the chinch bug population.
One is indeed surprised to learn that
the farmers of 1860 were just about as
much aware of this pest as are the farm-
ers of 1958. In 1861 Thomas (1865:
466-7) observed:
Although we cannot predict with certainty
one season the action of insect enemies for the
next, yet we often can from the character of
the season itself, know that certain species are
likely to be upon us in increased numbers.
This was the case the present season in re-
gard to the appearance of the “Army-worm.”
The cold, cloudy spring hanging so long before
opening into summer weather, caused the ex-
clamation from several of our older citizens,
“T wouldn’t be surprised if we had the Army-
worm this season.” Although this was rather
guessing, yet there evidently pervaded the
minds of the elder settlers a semi-conscious
feeling of dread in regard to this insect, which
most assuredly originated from the similarity
in this spring to the previous seasons when it
had appeared. And when the long dry weather
we sometimes have in June and July has
parched the vegetation, we may expect the
grass-hoppers to multiply rapidly, and by their
attacks on the plants already struggling for
life, to soon effect a far greater injury than
the same attack made on vigorous plants
would have done.
Later, Thomas (1880:242) observed,
“The high temperature of 1854, ’71 and
’74, together with the diminished rainfall,
furnish the key to the cause of the great
development of the Chinch-bug during
these years.”
One could cite hundreds of quotations,
from the Prairie Farmer and other early
farm papers, concerning damage by the
chinch bug and other field crop pests that
would put the potato beetle reports to
shame. But let the words of Walsh and
of Thomas suffice. Walsh wrote as fol-
lows:
It is only two years since the entire wheat
crop of the State was so damaged by the chinch
bug that a great deal of it was not cut at all,
and a great deal that was cut barely paid for
the harvesting. Scarcely a year elapses but
what more or less damage is done to it by this
insect, and by the Hessian*fly and the wheat
midge. A large breadth of winter wheat,
which is commonly supposed to be “winter-
|
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116 Ittinois NAarurAL History SurvEY BULLETIN Vol. 27, Art. 2%
. ~
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AREA OF STUDY ABOUT 120.000 SQ. MI.
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DISTRIBUTION OF DENSE POPULATION OF
CHINCH BUG, BLISSUS LEUCOPTERUS (SAY)
mmm SERIOUS DAMAGE TO CROPS tsa SLIGHT DAMAGE
@
1
in
ry Survey and its parent organizations make possible the study of population trends
Maps of Illinois and parts of adjoining states on which are shown areas of serious damage, slight damage, and no damage by chinch bugs in 10
birds, and mammals.
years, 1840-1940. Records kept by the Illinois Natural Histo
such groups as insects, fishes,
December, 1958
killed,” is in reality killed by the Hessian fly;
and there may be, and probably are, many
other insects which depredate upon this crop,
but whose habits have not yet fallen under the
notice of entomologists (Walsh 1861:335).
Taking the average of years, we may safely
assume that a fifth part of the wheat crop—
or, which is the same thing, a quantity equal
to one-fourth of what we actually do harvest
—is destroyed by insects. Even at the low price,
therefore, of 75 cents per bushel, we have
over four and a half million dollars’ worth
of wheat annually destroyed by “little vermin
which it is not worth our while to notice.”
But this is not all. Other crops are damaged
by other insects, though not generally to so
ruinous an extent; so that we cannot put the
whole annual damage done by insects to the
State of Illinois at less than TWENTY MILLION
DOLLARS (Walsh 1861:336).
And Thomas (1865:457) wrote: “So
much has already been written in the pa-
pers of this State concerning the Chinch-
bug (Macropus leucopterus, Fitch,) that
I shall pass it by in this paper without
further notice.”
Shelford & Flint (1943) made a thor-
ough study of the history of the chinch
bug in Illinois. The figure on page 116
is presented to illustrate the type of his-
toric records that have been made and
preserved by the Natural History Sur-
vey. The data on which the figure is
based cover the century beginning in
1840. Records for subsequent years have,
of course, been kept. Similar data have
been collected for several other important
pests.
In the 1860’s and ’70’s, many measures
were proposed for control of the chinch
bug: abandon wheat and barley or corn;
burn fencerows and all wild grass areas
to destroy hibernating bugs; plant border
crops to retard migrations; fertilize crops
to get dense stands unattractive to the in-
sects; and construct barrier lines of lime,
salt, and carbolic acid solutions. “The
measure most widely used was the dusty
furrow. Each year saw some new version
of the furrow proposed, such as pouring
tar oil, road oil, or creosote into the fur-
row to form a barrier; covering the fur-
row with straw and setting it afire to de-
stroy the bugs; digging post-hole traps in
the furrow and later spraying the trapped
bugs with kerosene and burning them.
There was no great change until the
paper fence barrier, proposed in 1934,
was widely adopted, but even this barrier
Decker: Economic ENTOMOLOGY
117
was not without precedent; over 50 years
earlier the use of tar-covered boards set
on edge and placed end to end had been
proposed. ‘The later control measures,
like the early ones, were scheduled to be
used around harvest time. About 1945,
the paper fence barrier was practically re-
placed by the dinitro dust barrier, and in
another 10 years this was replaced by diel-
drin, sprayed on strips of ground along
the margins of small grain fields where
these fields adjoined fields of corn or later
maturing grain. The more aggressive fol-
lowers of research progress were spray-
ing entire fields of heavily infested wheat
as soon as chinch bug eggs began to hatch
so as to protect the wheat crop itself
from serious damage and to eliminate the
necessity of establishing a barrier of any
type 2 or 3 weeks later.
In the past century, progress has been
made in controlling many other insect
pests that attack cereal and forage crops.
Among the most important of these pests
are the grasshoppers, the cutworms, the
white grubs, and the hessian fly. Instead
of attempting to summarize in detail, we
note here some of the general trends in
this area of insect control.
Before extensive agricultural develop-
ment of the state, a large part of Illinois
consisted of broad expanses of prairie
grass, much of which was replaced by
timothy and other tame grass or cereal
crops planted by farmers. Insects prefer-
ring these crops became notorious pests,
but as the acreage of grasses was reduced
as a result of increased legume produc-
tion, certain insects began to decline in
importance. "These included the white
grubs, the billbugs, the armyworms, the
sod webworms, and the corn root aphid.
The burrowing webworm and the cut-
worm Luperina stipata have all but dis-
appeared; not a single specimen of either
has been received by us for identification
in the last 20 years. As the rail fence was
replaced by the wire fence, and roadsides
and ditch banks were graded or otherwise
cleaned up, the amount of giant ragweed
and elderberry available to insects was
greatly reduced, so that the common stalk
borer became less important and the old
spindleworm was practically extermin-
ated. Likewise, as the pot holes and low
spots were drained, wireworm damage in
118
those areas declined steadily. Conversely,
in certain dry, sandy areas which were
brought under irrigation wireworm dam-
age increased.
As legume production increased, the in-
sect pests of legumes tended to increase.
Notable examples are the clover leaf wee-
vil, clover root borer, pea aphid, bean leaf
beetle, sweet clover weevil, green clover-
worm, and spotted alfalfa aphid.
Two attempts to initiate and promote
the commercial production of sunflowers |
in Illinois were doomed to failure largely
because of the overwhelming insect prob-
lems encountered when many species from
the native sunflowers swarmed onto the
cultivated varieties. In contrast, we find
that in extreme southern Illinois cotton
production survives in a rather unfavor-
able climate, and under other adverse
conditions, largely because important cot-
ton insects are absent and planters are
spared the cost of extensive insect control
measures.
Pests of Forest and Shade Trees
and Ornamental Plants
Effective control measures are now
available for most of the insect pests of
trees and ornamental plants; yet man
seems to have little success in combating
these insects. It is not that these insects
are new or relatively unknown, for the
majority of these pests were recognized
and well known prior to 1850. The bark
lice (scale insects), round-headed borers,
flat-headed borers, bark beetles, bagworm,
walnut caterpillars, cankerworms, and
the 17-year locusts are frequently men-
tioned in the Illinois entomological writ-
ings of a century or more ago. Chemical
control measures were not available at
that time, but some of the proposed meas-
ures were partially effective and more or
less practical. Mechanical barriers and
sticky bands were used to control the can-
kerworms, sometimes successfully and
sometimes not. It now appears that im-
proper timing and failure to recognize
the difference between the spring and the
fall cankerworms accounted for most of
the variation in control. Hand picking
was often mentioned and, according to re-
ports, if done diligently it was effective
in controlling the bagworm, the walnut
caterpillars, and the tent caterpillars.
Ittrnois NatuRAL History SURVEY BULLETIN
Vol. 27, Art. 2
Hand grubbing, with a wire or knife, was
considered an effective means of control-
ling several species of borers.
types of soapy washes were proposed for
the control of aphids and scale insects, but
perhaps the most positive, wisest, and
most ingenious of all recommendations
was that proposed by Dr. Mygatt (1855:
516) in his essay on the bark louse:
“Whether you choose a seedling or graft,
by all means TRANSPLANT A CLEAN TREE,
if you have to occupy hours and even days
in examining and clearing your trees
from every scale.”
As insecticides and means of applying
them were being developed for use on
various agricultural crops, it was nat-
ural that most of them would be tested
to determine their potential usefulness in
controlling insects attacking trees. The
value of Paris green in controlling the
cankerworms was established at a very
early date. By 1910 lead arsenate, first
developed in 1891 for use against the
gypsy moth, was being recommended for
a variety of leaf-eating insects, and by
1925 high-powered sprayers, dusters, and
even airplanes had been developed and
were quite generally available for use in
treating both shade and forest trees. Nev-
ertheless, progress was slow; apparently
the weather and tree protection have
something in common—everybody talks
about them, but nobody does anything
about them.
The average citizen who professes an
interest in and a love for trees is some-
times like the kibitzer who, at an active
poker table, talks a good game, but, for
reasons best known to himself, fails to put
his money on the line. In the past 2 years
in many Illinois communities, beautiful
landscape plantings, such as juniper, val-
ued at hundreds of dollars were rendered
unsightly and in many cases were killed
outright by the bagworm; a dollar’s worth
of malathion, or the old faithful, lead
arsenate, and 30 minutes’ time could have
prevented any damage. In some commu-
nities there has been a wholesale loss of
elm, oak, and birch trees of inestimable
value and irreplaceable in less than 3 dec-
ades; little evidence was available that
control measures were even considered.
This seeming indifference in some com-
munities is partially offset by the genuine
Several ©
December, 1958 DECKER:
interest of a number of ardent tree lovers
and conservationists in other communities.
Some of these tree lovers, however,
clamor for more research without mak-
ing full use of the control measures al-
ready available. Scientists have spent
many years in developing fairly efficient
and practical control measures for 90 per
cent of the insect pests affecting shade
trees and ornamental plants, yet we find
that these measures either are ignored or
are employed in less than 1 per cent of
the cases in which they might be useful.
It seems doubtful whether administrators
will feel justified in diverting any con-
siderable portion of their funds to similar
projects until there is evidence that the
control measures already recommended
are being put to better use. A recently
published circular (English 1958) will
bring interested people up to date on con-
trol of insects attacking ornamentals and
shade plants.
Insects Attacking Man and Animals
Entomology has made its most pro-
found and spectacular advances of the past
100 years in combating those insects that
are pests to man and animals. There seem
to be two good reasons why this is so. In
the first place, we have learned consider-
ably more of the habits and relative im-
portance of these pests than was known in
1858, and, in the second place, as the
medical implications of these pests became
apparent, state and federal public health
agencies, men in many branches of science,
and the general public gave wholehearted
support to large research and action pro-
grams.
Early Illinois entomologists had col-
lected and identified many species of
ticks, mites, mosquitoes, and flies, and it
did not require the services of a scientist
to advise farmers that large numbers of
these species were sources of annoyance
to their livestock, their families, and them-
selves. A couple of very casual comments
adequately attest to the ferociousness of
these pests: ‘There are prairies in Cen-
tral Illinois, as I am credibly informed by
-numerous witnesses, across which it is im-
possible to ride or drive a horse in the
heat of a summer’s day on account of
the Tabanus’” (Walsh quoted in Cresson
et al. 1865:18). The genus Simulium in-
Economic ENTOMOLOGY 119
cludes “the Buffalo-fly of Illinois and the
West, which I have observed killing poul-
try in great numbers, and which is known
to torment horses and other animals to
death, when very numerous” (Barnard
1880:191).
While these reports may sound far-
fetched and exaggerated, the latter is sup-
ported by a more recent experience. In
10 days of April, 1945, black flies killed
125 head of horses and mules and untold
numbers of poultry in Franklin and Wil-
liamson counties, Illinois.
Possible relationships between these
insects and several of the most dreaded
diseases known to occur in the state were
unknown in 1858 and for the most part
were unsuspected. For example, no one
thought of connecting the common house
fly with the spread of cholera that took
the lives of one-tenth of the population
of several western []linois communities in
the 1830’s or with the outbreaks of ty-
phoid fever and dysentery that were so
common during and immediately after
the Civil War.
It seems ironic that B. D. Walsh, the
first State Entomologist, was driven from
his farm near Cambridge by a malaria
epidemic and that he never suspected the
mosquitoes that increased with the dam-
ming of the river as being responsible for
the epidemic. All we know of this inci-
dent is contained in two sentences of
Walsh’s obituary by C. V. Riley (1869-
70267):
Finally, a colony of Swedes settled in his
neighborhood, and, by damming up the water
at Bishop Hill, produced so much miasma in
the vicinity, that very much sickness prevailed
there. His own health in time became im-
paired, and at the suggestion of M. B. Os-
born, of Rock Island, he removed to that city
in 1851, and entered into the lumber business.
Indeed, there is every reason to believe
that neither Walsh nor any of his con-
temporaries even suspected the relation-
ship between mosquitoes and malaria. In
his zeal to protect all beneficial insects
and to maintain the balance of nature,
Walsh was inclined to regard house flies,
horse flies, and mosquitoes as_ possibly
more beneficial than destructive. In 1865
he was quoted as saying:
The scheme of the Creation is perfect and Na-
ture is never at fault. It is only when Nature’s
120
system is but half understood, that we heed-
lessly complain of its imperfections. We blame
the house-flies for annoying us, and fail to see
that in the larva state they have cleared away
impurities around our dwellings, which might
otherwise have bred cholera and typhus fever.
We execrate the blood-thirsty mosquito, and
forget that in the larva state she has purified
the water, which would otherwise, by its ma-
larial efHuvia, have generated agues and
fevers. In all probability, when we rail at the
Tabanus that torment our horses in the summer,
we are railing at insects which, in the larva
state, have added millions of dollars to the
national wealth, by preying upon those most
[insidious] and unmanageable of all the insect-
foes of the farmer—subterraneous, root-feeding
larvae (Walsh quoted in Cresson et al. 1865:
18).
An editor of The Practical Entomolo-
gist, in commenting on Walsh’s paper,
cautioned his readers:
Before you undertake to kill off the larvae
of the Horse-flies and the Mosquitoes, you had
best make yourself quite sure that they are
really your enemies, and not, as Mr. Walsh
maintains, some of your very best friends
(Cresson et al. 1865:18).
Flies and mosquitoes passed practically
unmentioned until about 1880 when, be-
cause of the insects’ annoyance and nui-
sance characteristics, a few workers began
to investigate suppressive measures. Win-
dow screens and the use of smoke came
into the picture first, followed by oil
sprays, crude repellents, and several fly
traps. If we exclude the modern insecti-
cides developed since 1940, most of the
control measures that are recommended
today for the control of flies and mos-
quitoes had been developed by 1900. By
the combined use of drainage, good sani-
tation practices, screening, and the known
insecticides such as lime, borax, oils, ar-
senicals, and pyrethrins, public health
agencies made remarkable progress in re-
ducing the incidence of insect-borne dis-
eases, but it was not until DDT and the
more recent synthetic organic insecticides
became available that it was possible to
reduce fly and mosquito numbers to the
near vanishing point and to eradicate al-
most all insect-borne diseases of man.
Shortly before the outbreak of World
War I, the country embarked on an all-
out “Swat-the-Fly” campaign that car-
ried over into the dairy industry. This
campaign stimulated interest in the devel-
opment of sprays for use on livestock, as
Intinois NatrurAt History SurvEY BULLETIN
Vol. 27, Art. 2
well as space sprays for use in and around
buildings.
Unfortunately, many of the formula-
tions used prior to the late 1930’s were
only partially effective
flies, and in many cases the injury they
inflicted on cows exceeded the benefits de-
rived. It was difficult, if not impossible,
to establish clearly the fact that flies did
affect milk production and that good fly
control would pay dividends in the form
of higher milk production. In the last
10 years, with the new insecticides such
as DDT, methoxychlor, and several ef-
fective organo-phosphates, and with some
repellents far more effective and much
more persistent than anything available
prior to 1940, it has been possible to dem-
onstrate that good control of flies,
whether they be tabanids, stable flies, or
horn flies, will result in an increase of
milk production of as much as 10 to 25
per cent. ‘The exact gains depend upon
the intensity of the fly population, the
species involved, and the duration of the
attack. Significant findings in this field
have been reported in a number of scien-
tific articles (Bruce & Decker 1951, 1957,
1958; Bruce 1952, 1953).
BIOLOGICAL CONTROL
Man discovered at a very early date
that not all insects are bad, that some are
definitely his allies, some are indifferent
or neutral, and some are in the category
of Dr. Jekyll-Mr. Hyde—half good and
half bad. Walsh, Le Baron, Thomas, and
other early entomologists in their writ-
k
i
’
in controlling —
ings repeatedly referred to the necessity —
of distinguishing between man’s foes and
friends in the insect world, and empha-
sized, as did their successors, the import-
ance and potentialities of parasites and
predators in the natural control of insects.
In December, 1854, William Le Baron,
who 16 years later became the second
State Entomologist of Illinois, wrote:
Birds benefit the agriculturist by destroying
countless myriads of noxious insects, whilst
they injure him by consuming a part of those
products which he would fain reserve for his
own exclusive benefit. But it is the universal
testimony of those who have investigated the
matter, that the evil compared with the good
which they accomplish is extremely trivial.
Probably every reader of ornithology will call
December, 1958 DECKER:
to mind, in this connection, the computation of
Mr. Wilson the ornithologist, the result of
which was, that the single species of Red-
winged Blackbird, which is usually considered
one of the greatest pests of the farmer, con-
sumes in one season, in the United States, six-
teen thousand and two hundred million of
noxious insects (Le Baron 1855:559-60).
In an essay on insects, prepared in 1861
at the invitation of the Illinois Agricul-
tural Society, Cyrus Thomas (1865:462,
464) made several pertinent comments
on insect control measures, the balance of
nature, and the biological control of in-
sects:
When we have obtained a complete knowl-
edge of the laws of nature, and shall have at-
tained to perfection in agricultural pursuits,
then most assuredly our reliance for a check
upon these insect enemies will be upon the
parasites a kind Providence has provided for
our benefit. And the reason for so doing will
be that then we will work in accordance with
the laws of nature which are adapted to our
best method of living and acting. Then if this
theory be true, the nearer we can approach
such a condition, individually or collectively,
the better it will be for us.
Let the birds go unmolested, or even go so far
as to entice them to abide near you. Learn to
distinguish insect enemies from insect friends,
and when you find the hiding places of the
latter, as far as possible, protect them from
injury. When you find a swarm of ‘“Lady-
bugs” huddling around the root of a tree in
the winter, throw a few dry leaves over them
that the birds may not see them. When you
see the eggs of the Syrphus fly lying singly
among those of the Aphis, do not molest it, for
the young larvae will surely destroy that nest.
And when the bright banded flies hover like
bees around you, during the hot days of sum-
mer, while resting beneath the shade, brush
them lightly away, and remember they are
your friends. And when you see the eggs of
the Lace-winged fly (Hemerobius) mounted on
their long stalks on the leaves of your plants,
let them alone, the voracious larvae they pro-
duce will soon destroy the most numerous
colony of plant lice.
Benjamin Walsh (1861 :339-40, 341)
likewise had something to say about the
balance of nature and the value of para-
sites and predators:
Now it is universally the case, that when-
ever man, by his artificial arrangements, vio-
lates great natural laws, unless by some arti-
ficial means he can restore the overturned bal-
ance, he pays the penalty affixed to his offense.
The voluptuary may overload his stomach, but,
unless he has recourse to his dinner pill, he
pays the penalty of an indigestion. So with the
farmer and the horticulturist. Until they can
Economic ENTOMOLOGY 121
restore the natural equilibrium which has been
disarranged by their artificial processes, they
pay the penalty in the damage inflicted on
them by plant-feeding insects. They must as-
sist nature, whenever, for necessary purposes,
they have thwarted and controlled her, if they
wish to appease her wrath.
If these views be correct, it would seem to
follow, as a necessary consequence, that one
of the most effectual means of controlling
noxious insects is to be found in the artificial
propagation of such cannibal species as are
naturally designed to prey on them.
Although, so far as I am aware, cannibal
insects have never yet been bred for utilitarian
purposes, yet it is by no means an uncommon
practice to collect such as are found at large
in the woods and fields, and apply them to sub-
due some particular insect that is annoying us.
The foregoing quotations portray not
only the profound interest in biological
control that these early entomologists pos-
sessed but also the breadth and depth of
the general knowledge of the day.
Forbes, who followed Thomas as State
Entomologist, was likewise interested in
parasites and predators. The fact is im-
pressive that, in studying the biology and
ecology of insect pests, these men invaria-
bly made extensive notes on the parasites
and predators encountered. While others
before him had made notes of entomopha-
gous fungi and other evidences of disease,
Forbes was the first to examine the possi-
bilities of control of insects by their dis-
eases. In fact, he is regarded by many as
the father of insect pathology in the
United States. His work on the chinch
bug fungus and the work by Dr. F. H.
Snow of Kansas are outstanding classics
of early research in this field.
Forbes did not limit his interest and
research in insect pathology to chinch bug
diseases. He noted, and in many cases
studied in great detail, the diseases found
in numerous lepidopterous larvae, aphids,
white grubs, grasshoppers, and_ several
other insects. In the late 1880’s he was
strongly advocating more thorough stud-
ies on the possible advantageous uses of
contagious insect diseases, and his Eighth
Report (Nineteenth Illinois Report),
published in 1895, contained a monograph
of nearly 150 pages on chinch bug dis-
eases. In general, the success of attempts
to propagate insect diseases and to dis-
seminate them as a means of controlling
noxious insects in Illinois has not been as
122
spectacular as sponsors and interested ob-
servers had hoped. These projects have
been greatly underestimated by the pub-
lic; control of insects by their diseases has
a value that should not be ignored.
If nothing more, these studies demon-
strate the important role that insect dis-
eases play in the natural control of many
important pest species. They also shed
light on the epizootiology of these dis-
eases, which may prove to have even fur-
ther value. Unfortunately, in practically
all cases these projects were initiated on
the premise that an epidemic would be
initiated that could and would completely
eliminate the pest species in a matter of
days or weeks. When extermination of
the offending pest was not immediately
forthcoming, public sentiment turned
from hope to disgust and ridicule, and re-
searchers were forced to abandon their
studies for lack of financial support. It is
doubtful whether there is a single case in
which an honest appraisal of the long-
range or even the immediate value of dis-
ease inoculation or dissemination, or a
combination of both, has been made. In
recent years we have belatedly come to
realize that insect pathogens have not
been adequately explored nor their poten-
tial value determined. We and others are
renewing our efforts in this basic field of
research.
The performance of a protozoan dis-
ease of the European corn borer, a disease
which, like the parasites of the hessian fly,
apparently accompanied the host when it
migrated to North America, seems worthy
of mention. In Illinois the disease was
first observed in the north central part of
the state in 1945, 6 or 7 years after the
borer made its first appearance in Kanka-
kee County. The disease was artificially
introduced into all sections of the state by
colonizing disease-infected borers in many
widely scattered counties. It is now prev-
alent in all parts of the state and has for
several years been an important, if not
the most important, factor in holding
corn borer populations to relatively low
levels, where they can be successfully con-
trolled by other means at a greatly re-
duced cost.
In a co-operative effort, the Illinois
Natural History Survey, United States
Department of Agriculture, and Illinois
Ittinors NaturAL History SuRVEY BULLETIN
Vol. 27, Art. 2
Conservation Department introduced a
virus disease obtained from Canada to
combat a serious outbreak of a pine saw-
fly, Neodiprion sertifer, that in 1952 was
raging out of control in the Henderson
State Forest. The virus took hold in a
spectacular fashion, and sawflies died by
the thousands. Whether the virus can be —
given full credit or not remains to be de-
termined. In any case, the sawfly has not
been reported as doing serious damage in
that area since 1953.
The value of parasites imported from
abroad to help control accidentally intro-
duced species has also been underesti-
mated. Here, as in an effort to control
an insect pest by disease, the public seems
to expect the immediate annihilation of
the pest species or it regards the effort as
a complete failure. To demonstrate that —
a species need not be annihilated to be
prevented from causing appreciable dam-
age, let us look at the record. The hes-
sian fly and the wheat midge were both
introduced in colonial days as immigrants
from Europe. Fortunately, several of
their European parasites came along with
them in the same lots of straw, but, as
usually happens, each pest reproduced
and spread faster than its parasites. In
due time the parasites overtook their hosts,
and, for over a century, they have been
important factors in preventing these
pests from eliminating wheat production
from the list of agricultural enterprises
in Illinois.
When the oriental fruit moth appeared
in Illinois in 1927, the Illinois Natural
History Survey, in co-operation with the
United States Department of Agriculture,
obtained, for release in Illinois, oriental
fruit moth parasites (principally Macro-
centrus ancylivorus) reared in New Jer-
sey. These were colonized at several
points in the infested southern [Illinois
counties. At first the results of the ex-
periment did not appear promising, but
consistent recoveries were made in 1934,
and eight surveys made since then have
shown that parasitism by this species
ranged from 17.3 to 53.2 per cent and
averaged 36.5 per cent. While the para-
site has not eliminated its host, it has held
the population to a level where peaches
can be adequately protected with a mini-
mum use of insecticides. The average
December, 1958 DECKER:
percentage of the fruit infested since the
establishment of the parasite is less than
one-tenth what it was before colonization
of the parasite was initiated.
Shortly after the European corn borer
made its appearance in the Midwest, at-
tempts to introduce several of its parasites
into the infested area (1926-1930) were
relatively, if not wholly, unsuccessful.
Later attempts, in which the I]linois Nat-
ural History Survey and the United
States Department of Agriculture co-op-
erated (1944-1950), were more success-
ful, and a Tachinid fly, Lydella stabulans
grisescens, became firmly established in
all sections of the state. Surveys made
annually for the past 10 years have shown
that, for the state as a whole, 15 to 40
per cent of the overwintering corn borers
are parasitized and destroyed by this fly.
In many instances parasitism in some of
the northern Illinois counties has run as
high as 80 to 85 per cent. While this
parasitic fly has not eliminated the corn
borer, it plays a very important role in
holding this pest in check.
VALUE OF INSECT CONTROL
Man’s progress in applied entomology
is partly obscured by the ever-changing
circumstances and conditions of insect
control. Quantitative data on the exact
magnitude of insect damage are generally
unavailable, and only the more or less
catastrophic insect outbreaks are ade-
quately recorded in the literature. ‘There
are few specific points of reference with
which we can compare the present with
the past. Our memories are often faulty.
We recall that Grandfather had a home
orchard and how much we enjoyed the
fruit; only after prolonged meditation do
we also recall that only 1 apple in 10 was
fit for storage in the fall, and that even in
preparing a pie from the stored apples
Grandmother had to cut out numerous
areas damaged by codling moth.
Despite the paucity of precise quanti-
tative data, entomologists have developed
practical control measures for a long list
of once serious pests. Orchardists are
now able to produce fruit crops 90 to 99
per cent free of insect damage instead of
crops only 10 to 50 per cent free of in-
sect damage, as they were 100 years ago
Economic ENTOMOLOGY 123
or as they are now in abandoned or un-
sprayed orchards. The Colorado potato
beetle, which came close to eliminating
Irish potato production just about 100
Table 1.—Number of acres treated with
insecticides and estimated profit from treat-
ment for a few important insect pests of
cereal and forage crops in Illinois, 1953-1957.
NUMBER OF NUMBEROF ESTIMATED
YEAR PEsT SPECIES ACRES PRroFIT FROM
CONSIDERED* ‘TREATED ‘TREATMENT
1953 10 770,625 $ 8,596,995
1954 7 1,095,165 7,130,258
1955 9 1,532,859 13,983,855
1956 10 1,405,624 7,097,630
1957 11 934,224 2,696,960
Average 9 1,147,699 § 7,901,140
*Insects considered in these surveys: spittlebug, leaf-
hopper, spotted alfalfa aphid, sweet clover weevil, pea
aphid, soil insects, chinch bug, cutworms, grasshoppers,
European corn borer, and fall armyworm.
years ago, is no longer regarded as a seri-
ous pest. The grasshoppers, the army-
worms, and the chinch bug, which less
than a century ago caused many Midwest-
ern pioneers to give up in despair and to
abandon their farms, can now be con-
trolled with comparative ease. The prin-
cipal insect vectors of important human
diseases have been brought under control
to such a degree that the once dreaded
diseases—malaria, typhoid fever, dysen-
tery, cholera, and bubonic plague—are
little more than an unhappy memory.
Reasonably effective measures for the con-
trol of important household pests such as
the bedbug, cockroaches, stored-grain
pests, clothes moths, and. carpet beetles
have brought peace of mind to the house-
wife and have contributed much to in-
crease the comfort of the home. Measures
developed for the control of insects at-
tacking livestock—ticks, tabanids, stable
flies, lice, and screwworms—have contrib-
uted much to the livestock industry. The
successes mentioned above were attained
despite the drastic rise in level of accep-
tance imposed by the public, the United
States Food and Drug Administration,
and market grades and standards. Under
present regulations, the diseased and dam-
aged condition of fruits, vegetables, grain,
and other agricultural products that were
accepted at the turn of the century would
eliminate them from moving in interstate
124
commerce or even from being sold on the
local market.
Though it is not possible to establish
monetary values for each of the accom-
plishments just mentioned, the almost
$8,000,000 average annual profit, table
1, resulting from the use of insecticides
on cereal and forage crops in Illinois illus-
trates the benefits of entomological re-
search.
There are those who will say that ag-
riculture cannot afford the cost of insect
control or that the farmer dare not add
such charges to his overhead cost. Such
assertions are economically unsound. The
overhead charges associated with the
planting, cultivating, and harvesting of
each acre of crops are fixed. If a farmer
can increase yields sufficiently to provide
a cash return of two, four, eight, or more
times the cost of insecticide treatment,
the extra harvest is produced much more
cheaply than the rest of the crop and
thereby increases net profits and effects a
reduction of operating costs.
Insect control—or the lack thereof—
may have an indirect bearing on economic
and sociological considerations in addi-
tion to those related to crop savings or
crop losses. By increasing per-acre yields,
maximum utilization of insect control
measures might enable upwards of a mil-
lion acres of Illinois farm land to be re-
tired from cultivation and put to new
uses. Some reactionaries will argue that
increased yields would mean overproduc-
tion and lower prices; this argument has
been applied to almost every new techno-
logical development.
For years we have been attaining pro-
duction goals by mining the soil—by
wringing from it the fertility that must
be replaced if future generations are to
have their share. Economically and mor-
ally, we are obligated to produce maxi-
mum yields as efficiently as possible on a
minimum number of acres. The surplus
land should be removed from annual cul-
tivation and its fertility maintained or
improved with soil building practices em-
ployed until such time as an expanding
population requires further production.
Even if Illinois could afford to squander
its land resources and its manpower, the
support of research for effective insect
control would still be a foresighted invest-
Ittrnors Natura History Survey BULLETIN
Vol. 27, Art. 2
ment. When men of wisdom, interested
in the nation’s future, combine forces in
building a sound agricultural program,
insect control will rank high in the list of
technological musts.
EMPHASIS FOR THE FUTURE
Throughout the past century in IIli-
nois, the extent and variety of insect con-
trol problems, which were often of an
emergency nature, dictated that entomol- —
ogy be strictly applied and be aimed at
immediate, practical goals. Perhaps the
pressure for immediate, practical results
reached its peak in the mid-1940’s, when
a number of new and apparently highly
effective insecticides became available for
study and use. Everyone wanted to know
at once what these insecticides were good
for, how they should be used, and what
hazards might be involved in their use.
Now this pressure is subsiding; the IIli- —
nois farmer is in possession of reasonably —
practical control measures for most of
his important insect pests. Economic en-
tomology in Illinois is now in a position
to seek information on the basic problems
of insect control.
This statement does not mean that all
the insect problems of I]linois are solved ;
we should not be surprised that new prob-
lems will arise as new insect species are
introduced and as species already here
modify their habits or adjust their re-
sponses and behavior to an ever-changing
environment. However, we have appar-
ently reached a turning point that will re-
quire a revision of our responsibilities and
will materially alter our objectives and —
procedures.
With reasonably effective control meth-
ods available for most pests, and with the
majority of our basic crops in surplus
production, emphasis on the temporary
solution of immediate problems and on
increased production must logically be
shifted to the development of more basic
studies ultimately leading to new meth-
ods of insect control. A review of the his-
tory of chinch bug, armyworm, codling
moth, and potato beetle control makes it —
apparent that progress came in_ steps
spaced 10 or 20 or more years apart. In
entomology, as in other branches of sci-
ence, real progress is made through the
December, 1958
development of some new fact, some bio-
logical or chemical law or principle re-
ferred to as a “break-through,” discov-
ered by scientists pursuing basic research.
Practically all entomologists agree that
Nature is more efficient than man in con-
trolling insects; there is an urgent need
for a return to the basic study of insect
biology and ecology and for expanded
work in the promising field of biological
control. With a more thorough knowl-
edge of the environmental factors that
favor insect reproduction and_ survival
and of those factors detrimental to these
processes, man might conceivably control
some pests by diminishing the favorable
factors, enhancing the unfavorable fac-
tors, or pursuing both courses. This type
of basic research is expensive, and prog-
ress comes slowly, but successful projects
based on the accumulated results of such
research pay handsome dividends.
While more intensive studies in insect
genetics, ecology, and biology may play
increasingly important roles in the devel-
opment of new insect control procedures,
man will for many years find it necessary
to rely on chemical weapons—insecticides
—to fight many of his insect pests. As
more and more toxic insecticides are de-
veloped, it becomes increasingly important
that they be thoroughly tested for safety
before they are placed in general use. The
evaluation of insecticide residues, their
degradation products, and possible ad-
verse effects on man and other animals,
is currently time consuming and expen-
sive. We must undertake considerable
basic research to discover and to develop
basic principles or natural laws that will
simplify insecticide evaluation and reduce
the cost of pursuing such routine studies.
Come what may, man must never be-
come complacent with his temporary suc-
cesses nor assume that the insects have
given up or will give up their struggle for
supremacy. We must be ever mindful of
the theses of L. O. Howard (1933) that
insects are better equipped to occupy the
earth than are humans; insects have been
on earth for 40,000,000 years, while the
_ human race is only 400,000 years old. As
Forbes (1915:2) soberly asserted:
The struggle between man and insects began
long before the dawn of civilization, has con-
tinued without cessation to the present time,
Decker: Economic ENTOMOLOGY 125
and will continue, no doubt, as long as the hu-
man race endures. It is due to the fact that
both men and certain insect species constantly
want the same things at the same time. Its
intensity is owing to the vital importance to
both of the things they struggle for, and its
long continuance is due to the fact that the
contestants are so equally matched. We com-
monly think of ourselves as the lords and con-
querors of nature, but insects had thoroughly
mastered the world and taken full possession
of it long before man began the attempt. They
had, consequently, all the advantage of a pos-
session of the field when the contest began,
and they have disputed every step of our in-
vasion of their original domain so persistently
and so successfully that we can even yet
scarcely flatter ourselves that we have gained
any very important advantage over them.
There seems to be little question that
insects will continue to demand tribute of
enormous proportions which will have to
be paid in terms of damage, pain, and
suffering caused by the insects, or in ex-
penditures for insect control. Man may,
through judicious expenditures for re-
search and practical insect control meas-
ures, reduce or minimize the tribute to be
paid, but he can never eliminate it entire-
ly. In this connection, it should again be
noted that entomology is not static. In-
sects, as highly versatile living organisms,
are constantly changing to meet each
change in the environment, whether it be
biological, physical, or chemical. If we
are to hold our own in this continuing
battle, research must be carried on un-
diminished, and, if we are to make prog-
ress, research must be expanded.
At the moment, entomology and re-
lated biological sciences appear to be los-
ing ground. State and federal appropria-
tions have not kept pace with rising costs.
Basic research is currently financed
largely by grants from the principal en-
dowed foundations. If it were not for
funds made available by chemical and
other large industrial companies, applied
research in entomology would have been
greatly handicapped and curtailed-in the
last decade.
Today, faced with the fact that an-
other nation was the first to launch a
man-made earth satellite, America is sub-
jecting her own research facilities and
educational system to critical review. At
the moment, the physical sciences are in
the limelight and apparently stand to
profit from increased emphasis. That the
126 Intinois NATURAL History SurvEY BULLETIN
natural sciences can safely be relegated to
a secondary or back-seat position is open
to question. Almost 100 years ago, B.
D. Walsh, deploring American neglect
of the natural sciences, observed: ‘“They
manage these things better in Europe. In
Russia and other continental states, En-
tomology in its rudiments is made a por-
tion of common school education” (Anon.
1860:12).
There is every reason to believe that
current entomological research in other
countries is in no way inferior to our
Vol. 27, Art.
own. If the biological sciences, including
entomology, are neglected in a revitalized
educational program, America may find
herself again out-distanced by other coun-
tries—by men who are trained in a sci-
ence-oriented system that is balanced to
include all areas of scientific endeavor. If
one step forward in the physical sciences
causes us to slide two steps backward in
the biological sciences, all our efforts spent
to initiate a sound program for the ad-
vancement of science—all science—will
have proved useless.
Faunistic Surveys
N their beginnings and early develop-
ment, investigations of the fauna of
the Midwest differed in several respects
from similar endeavors in other parts of
the world. The Midwest was explored
and collected intensively considerably
later than the eastern American seaboard,
so that the advances in the knowledge of
the North American fauna made in the
eastern United States were available as
an aid to moderately rapid advances when
faunal studies were begun in the Mid-
west. In the eastern United States and
also in Europe, systematic investigations
were begun in response to man’s _in-
herent curiosity concerning the kinds of
life in his surroundings and were de-
veloped to a considerable state of ad-
vancement chiefly under this stimulus.
In the Midwest, the first serious syste-
matic efforts were undoubtedly begun in
answer to pure curiosity, but almost im-
mediately after their inception, especially
in Illinois, these studies were picked up
and swept along by the tremendous de-
mand for identification caused by the
agricultural and scientific developments
of the latter half of the nineteenth
century.
EARLY BACKGROUND
The sudden formation of natural his-
tory societies in the Midwest during the
1850’s — at Louisville in 1851, Grand
Rapids in 1854, Milwaukee in 1855, and
Chicago in 1856—gives an impression in
retrospect that before that decade there
were no naturalists in the area. This was
far from the case, for a few enthusiastic
naturalists were active in various lo-
calities through the Midwestern region
even before these dates.
Among the Midwestern naturalists
were the famous zoologists Thomas Say,
C. A. Le Sueur, and G. Troost, living
and working on the banks of the Wabash
River at New Harmony, Indiana, in the
1820’s and 1830's, and C. S. Rafinesque
at Louisville, Kentucky, in the 1810's
AEE RS ERT Ee ROSS
and 1820’s. Many other persons collected
material for these men or sent speci-
mens for identification to taxonomists in
the eastern United States or Europe.
The early faunistic workers of the
1840’s and the 1850’s in Illinois included
such men as Cyrus Thomas, John A. and
Robert Kennicott, J. B. Turner, and
Benjamin D. Walsh, all of them self-
taught naturalists. These and other en-
thusiasts made accurate observations on
the fauna, built up collections of various
animal groups, and kept in touch with
their confreres in the eastern states. The
Illinois entomologists published articles,
some of them in the Prairie Farmer, and
absorbed the ideas of such great early
entomologists as IT. W. Harris of Mas-
sachusetts and Asa Fitch of New York.
In Illinois the State Agricultural So-
ciety, formed in 1853, was an important
agent in bringing together Illinois zo-
ologists, entomologists, and botanists into
an organized natural history society. The
progressive officers of the Agricultural
Society were conscious from the first of
the destructive nature of insects and were
sufficiently versed in biological concepts to
realize that applied biology requires a full
knowledge of all forms of natural life.
To encourage acquisition of this knowl-
edge, the Agricultural Society offered
prizes at its state fairs for collections in
natural history fields. In 1854 Wm. J.
Shaw of Tazewell County won first prize
for the “Best suite of the animal king-
dom, including insects and animals in-
jurious to the farmer” (J. A. Kennicott
1855:122). In 1855 Robert Kennicott
won two prizes, one for the “Greatest
and best collection of named insects,” the
other for a zoological collection; in 1856
he won seven firsts—for a collection in
each of the following classes: shells, named
insects, zoology, botany, stuffed birds, rep-
tiles, and fishes (J. A. Kennicott 1857 :90,
142).
In the State Agricultural Society’s first
Transactions, three lists of animals for
Illinois were published, one on southern
[ 127 ]
128
Illinois birds by Henry Pratten (1855),
one on the Mollusca of southern I1linois
by H. A. Ulffers (1855), and another
(solicited by the Society’s secretary) on
the animals of Cook County by Robert
Kennicott (1855). It is interesting that
in this last article Kennicott recorded
“buffalo” and elk for Cook County and
noted that the “wild pigeon’ (passenger
pigeon) was “very abundant” and the
magpie “not uncommon in winter.”
For a few years after the first corpo-
rate form of the Illinois Natural History
Survey had come into being as the Illi-
nois Natural History Society, the Agri-
cultural Society published the proceed-
ings of the infant organization.
In Illinois the faunistic worker of 1858
had few of the work aids which we en-
joy today. The only Midwestern institu-
tional reference collection was that at
Northwestern University, built up by
Robert Kennicott and considered out-
standing in its day, although small and
limited in group representation compared
with collections now available.
Most zoologists accumulated their own
private collections, identifying their speci-
mens with the aid of the few books avail-
able and through consultation with other
naturalists. Few libraries existed in the
area. The reference shelves of the best
zoologists contained comprehensive treat-
ments covering the eastern North Ameri-
can fauna for most of the vertebrates and
the Mollusca. For the insects Say’s vol-
umes were available, but for many orders
his treatment was fragmentary. For most
insect groups and many other inverte-
brates, extremely helpful world synopses
had just been written by European au-
thors, and some of them contained sepa-
rate keys for the North American spe-
cies. Aside from these basic references,
there existed a number of journals carry-
ing short papers, some of them published
by the scientific societies of the Atlantic
seaboard states, where such societies had
been organized a century before their
Midwestern counterparts.
This period, the 1850’s, was a stirring
one scientifically. Europe had just wit-
nessed the successive development of com-
parative anatomy and physiology, the cell
theory, embryology, histology, and the
theory of evolution. These basic concepts
Intinors NArurAL History Survey BULLETIN
did not immediately influence faunistic
work in North America but they did so —
later to a greater and greater degree. In
North America prior to the 1850’s, the
great bulk of the invertebrate material,
including insects, had been sent to Euro-
pean specialists for description. Follow-
ing the pioneer examples of Frederick
Vol. 27, Art. 2.
Melsheimer and Thomas Say with in-—
sects and mollusks, American zoologists —
were beginning to describe more and_
more species of the native American —
fauna. In the invertebrate groups they
had virtually a virgin field, for in 1858
great numbers of species were still un-
known, and workable synopses were avail-
able for only a small proportion of the
native American fauna.
CHANGING HABITATS
Originally Illinois was chiefly a com-
bination of forested hilly country and flat
mesic prairies of a marshy nature. Inter-
spersed with these main types were sand
areas, bogs, river and stream _ habitats,
and other local areas of diverse kinds.
The rapid rise in the population of Illi-
nois in the mid-nineteenth century initi-
ated in the native vegetation drastic
changes which have progressed steadily
to the present time; these changes have
had a marked effect on the distribution
and composition of the animal life of
the state.
By 1858, towns or farms or logged-
over areas had broken up large tracts of
forest. Plowing had made great inroads
into the prairies. Large area drainage op-
erations in the marsh country had started
about 1850, had gained great momentum
by 1880, and by 1900 had turned the
great bulk of the marshland into farms.
The resultant changing ecology is a back-
ground feature important to keep in mind
when viewing the faunistic developments
outlined in this chapter.
PERIODS OF FAUNISTIC
ACTIVITIES
The faunistic activities of the Illinois
Natural History Survey and its prede-
cessors may be divided into three fairly
distinct periods, the initial, chiefly vol-
untary, period of roughly 1858-1869, the -
December, 1958 Ross:
expansion period of roughly 1871-1922,
and the specialized faunistic survey pe-
riod of roughly 1923 to date.
Initial Period, 1858-1869
The Illinois Natural History Society,
when formed in 1858, had as its primary
objectives the exploration of the biota of
Illinois and the establishment of a scien-
tific library. Encouragement of animal
studies was patently aimed at systematics;
yet even in the inaugural presidential ad-
dress by J. B. Turner there is more than
an overtone of putting systematics to
work. In the words of Turner (1859:
647),
A true philosophy, as it seems to me, would
never let us rest content till we had truly and
fully learned not the bare name and form,
but the final cause and use, the good and
evil, the full relation of each thing, object and
being, to all other beings, and especially to
man—to all his interests, enterprises, arts,
uses and developments, physical, mental and
moral.
At the anniversary meeting in 1860 at
Bloomington, certain objectives of the
Society were expressed differently but in
equally broad terms (Anon. 1860:3) :
It is the aim of the Society . . . to establish
a Museum of Natural History, at the State
Normal University, comprising every species
of plants, birds, shells, fishes, insects, quad-
rupeds, minerals and fossils, found in Illinois,
together with such collections from various
parts of the world as will assist our youth
in gaining a knowledge of the general studies
of nature.
The Natural History Society did in
fact found a museum at Normal, Illinois,
which served as a rallying point for zo-
ologists of the area. The Society’s papers
and proceedings continued to be published
by the Agricultural Society, which fur-
ther continued its active encouragement
of faunistic work by awarding prizes for
exhibited collections at the state fair.
At about this time several []linois nat-
uralists began publishing accounts of the
zoology of the state. C. D. Wilber
(18614) described a fossil mastodon,
Thomas (1861a, 18614) wrote lists of
mammals and of some insects, R. H.
Holder (1861a, 1861) wrote about birds,
and Walsh (1861-1868) published a re-
markably fine series of papers before his
FAUNISTIC SURVEYS
129
death in 1869. Although a skeleton net-
work of railroads crisscrossed the state,
most of the collecting was local, because
it had to be done as a hobby appended
to the naturalist’s business or other oc-
cupation; hence, the papers were based
chiefly on material from a few localities.
Collections exhibited at the state fairs
give another informative light on faunis-
tic activities of that time. At the 1859
fair three entries were exhibited, one a
red deer, another a collection of stuffed
birds, and the third a collection of in-
sects. In 1860 seven entries (Reynolds
1861:190-1) and in 1861 eight entries
(Reynolds 1865:137) were exhibited in
zoology. There were no more exhibits in
zoology until 1864; in that year the
winners were chiefly the Illinois Natural
History Society and Illinois Wesleyan
University at Bloomington (Reynolds
1865:310). Apparently these two groups
enjoyed some rivalry at that time in the
development of natural history.
An idea of the high merit of these ex-
hibits can be gained from the 1861
Awarding Committee’s remarks (Reyn-
olds 1865:149) on the insect exhibits:
In Entomology, a collection exhibited by
T. G. Floyd, of Macomb, entitled the exhibitor
to the “commendation” of the Society. In this
department, Dr. Charles A. Helmuth, of Chi-
cago, made a fine exhibition. His collection
of Beetles is very valuable and attracted
much attention. He has over 1100 species col-
lected in Illinois, besides many fine species
from other States and foreign countries. We
think him entitled to “very high commenda-
tion,’ especially for specimens exhibited be-
longing to the order of Coleoptera. But by far
the best collection exhibited was presented by
B. D. Walsh, Esq., of Rock Island. It is hardly
possible to speak in too high terms of this
extensive collection of the insects of Illinois.
So far as Illinois insects are concerned, it
outnumbers in the order of Coleoptera, the
collection of Dr. Helmuth, and is very full
in all the other orders. It could only have been
collected and arranged by an exercise of
industry, [perseverance] and skill, and by an
application of scientific knowledge, reflecting
great honor upon the collector and entitling
him to high rank among the Naturalists of the
State and of the country. The Committee
do not hesitate to pronounce his the “best
collection illustrating the Entomology of Illi-
nois,’ and unanimously award to him the
premium of the Society.
In spite of the achievements in faunis-
tic activities shown by both publications
130 ILtrnors NarurAL History SuRVEY BULLETIN
and exhibits, the Natural History So-
ciety itself faltered because it could not
make ends meet on private subscriptions
alone and by the end of the 1860’s was
a mere shell of an organization.
Expansion Period, 1871-1922
The establishment of the State En-
tomologist’s Office in 1867 and the in-
corporation of the Illinois Natural His-
tory Society into the State Board of Ed-
ucation in 1871 brought together as off-
cial state organizations two agencies in-
vestigating natural science and marked
the beginning of continuing state support
for faunistic programs.
The appointment of Walsh as first
State Entomologist had little effect on
this movement because Walsh confined
his official writings almost entirely to
nontaxonomic subjects. His successor,
William Le Baron, introduced serious
taxonomic contributions into the reports
of the State Entomologist in 1871.
In his first report as State Entomolo-
gist, Le Baron described a new species
of moth attacking apple, in his second
described four more new species of in-
sects of economic importance, and in his
third gave an outline of and key to the
orders of Illinois insects (Le Baron 1871:
20-3; 1872:117-24, 138-9, 140, 157-8;
1873:25). Here he called particular
attention to the great need for identifica-
tion aids in the pursuit of economic en-
tomology. Le Baron’s was the first of
much faunistic work which continued as
an integral part of the development of
economic entomology in Illinois. At al-
most the same time (1871), the educa-
tors and scientists of the state, alarmed at
the continued decline of their Natural
History Society, induced the legislature
to take over and assign the Society’s mu-
seum and library to the State Board of
Education in exchange for state appropria-
tions (Illinois General Assembly 1872:
151-2) for the Society’s continued growth.
Thus, the need for state aid in the de-
velopment of faunistics arose from two
different directions.
Both Le Baron and Thomas as State
Entomologists published many fine taxo-
nomic insect studies in their reports. Un-
der the auspices of the Illinois Museum of
Natural History, naturalists in the state
Vol. 27, Art. 2 —
published faunistic papers on a wide range —
of Illinois groups, including Crustacea,
fish, birds, reptiles, and insects. j
The period 1858-1878 witnessed the —
first concerted awakening of American
naturalists to the taxonomic opportunities
in the invertebrates, especially in the in- —
sects. Specialists in many states published ~
comprehensive treatises on orders or fam- —
ilies of insects of North America.
these animals, this was truly the age of —
North American discovery.
In 1877 the Museum of the Natural —
History Society, by that time known as
the Illinois Museum of Natural History, —
was separated into two institutions: the
Natural History Museum, designed as —
a public exhibition museum, in Spring-
field, and the State Laboratory of Nat-
ural History, at Normal (Illinois Gen-
eral Assembly 1877:14-6). The duties —
of the State Laboratory, presumably as —
set forth by Stephen A. Forbes, its Di- —
rector, stressed ecological approaches to —
the animal life of the state and in this —
policy reflected thoughts expressed by
Turner 20 years before. The primary in- —
tent of the systematic program described —
was “to monograph those groups which —
have not been thoroughly studied else-—
where” (Forbes 1882a:9).
In 1882 Forbes became State Entomol-
ogist, as well as Director of the State
Laboratory. Following the establish-
ment of both of these offices at Urbana
in 1885, the faunistic program received
great impetus. Reading between the lines
of the original reports of the Director,
it seems safe to surmise that by this time
the ecological studies already attempted
had highlighted the pressing need for the
accurate identification of the animal spe-
cies encountered in these studies. In the
revised list of duties of the State Labora-
tory we find the directive, “he [the Di-
rector] shall present for publication,
from time to time, a series of systematic
reports covering the entire field of the
zoology . . . of Illinois” (Illinois Gen-
eral Assembly 1885:23). In its Bulletin,
the Laboratory had previously published
many papers by nonstaff members, but
from this time on a larger and larger pro-
portion of these papers was the product
of staff members of the State Laboratory
or of the State Entomologist’s Office.
For —
December, 1958 Ross:
The main faunistic activities of these
staff members concerned aquatic organisms
and insects associated with the develop-
ment of ecology and economic entomol-
ogy. Forbes repeatedly mentions that the
most important tools of the biologist are
2
2
2
2
£
z
:
i
FAUNISTIC SURVEYS
131
roads traversed the state and these were
the only means of rapid travel. Collecting
was done intensively around a few head-
quarters, especially Urbana, Carbondale,
and Havana. On the Illinois River and
other waterways, boats were available
Field party of the Illinois State Laboratory of Natural History at one of several collecting
stations near Havana, 1894. This station was on the east shore of Thompson’s Lake, which has
since been drained. In the picture are, left to right, Frank Smith and Henry E. Summers, zoolo-
gists, Charles A. Hart, entomologist, and Miles Newberry, fisherman and boatman.
a reference collection for the identifica-
tion of specimens and a scientific library.
All staff members collected specimens as
part of their duties, and every effort was
made to obtain material from different
parts of the state and from areas of in-
terest in adjacent states. By 1894 the
collections were of sufficient magnitude
to be placed under the charge of a cura-
tor, C. A. Hart. In 1903 Hart became
Systematic Entomologist and Curator of
the insect collections, and R. E. Richard-
son was brought in to take charge of the
fish collections. In 1915 J. R. Malloch
Was appointed to assist Hart with the
insects.
Collecting conditions from 1870 to
well into the 1900’s were greatly dif-
ferent from those of today. A few rail-
for travel up and down the rivers. Local
travel was done by horse-drawn vehicles.
As late as 1900 Forbes (1901:3, 5-6)
wrote of the Laboratory:
Its field operations have been conducted mainly
from the Illinois Biological Station [at Ha-
vana and Meredosia] as a center,...
Besides this local work on the fishes of the
State, two extensive wagon trips have been
provided for, one made in the fall of 1899,
and the other in progress at this date [Sep-
tember, 1900]....
A considerable number of collections have
also been made by high school principals and
science teachers and sent to the Laboratory
in aid of this survey.
Hart and his assistants traveled to
various points by train and in each town
set up headquarters in a local hotel or
rooming house, hired a buggy, and made
132 Intinois NaruraL Hisrory Survey BULLETIN
day trips into the surrounding territory.
In this way, over the years a remarkably
fine collection of insects was built up
from almost every part of the state. The
establishment of the field laboratory at
Havana formed a basis for many seasons
of intensive insect collecting in the rich
waters of that area and on the extremely
interesting sand areas which line the east
bank of the Illinois River through sev-
eral counties.
At the present time such restrictions
on movement might seem a terrible handi-
cap, but one must remember that in those
days the land was not so intensively culti-
vated as it is at present. Within a very
short distance of almost any town, tracts
of virgin forest, prairie, marsh, or other
undisturbed habitats could be reached
with little effort. Many of the old virgin
landscapes which were the type localities
of Illinois species are now either flooded
by artificial lakes, under cultivation, or
covered by urban developments. Most of
the marshes, which were once common-
place, have been drained. Because of the
abundance and accessibility of varied
habitats, the early collections were both
large and diversified. The very nature of
the substation headquarters method en-
couraged the collection of all species of
insects in a given locality, rather than
specialization on any one group. Human
labor was relatively cheap; hence, pre-
parators and collectors could be_ hired
and trained at a nominal cost.
As a result, the State Laboratory in-
sect collections (which constituted also
the insect collections servicing the State
Entomologist’s Office) became the finest
which had ever been assembled for any
one state, and early in the twentieth
century the collections of fishes and cer-
tain other groups were equally fine. This
faunistic program reached a peak about
1910 and continued into the next decade.
In 1917, when the State Entomol-
ogist’s Office and the State Laboratory
were combined to form the present IIli-
nois State Natural History Survey, the
reorganization did not effect any changes
in the internal structure of the faunistic
staff. Immediately afterward, however,
the faunistic program began to dwindle.
Many of the well-trained personnel ac-
cepted positions in universities and other
Vol. 27, Art. 2
scientific centers which were growing
rapidly. World War I drew away much
of the younger help. Richardson concen-
trated on ecology. Hart, the work horse
of the entomological collections, died in
1918, and in 1919 C. P. Alexander was
appointed Systematic Entomologist. Al-
exander and Malloch worked chiefly on
stream surveys. The studies of Alexander
resulted in a report on the Vermilion
River (Alexander 1925). After the
resignations of Malloch, in 1921, and Al-
exander, in 1922, there were no faunistic
taxonomists left on the Natural History
Survey staff. No comprehensive faunistic
projects had been in operation for several
years, and these resignations left the
Survey without even curators.
Specialization Period,
1923 to Present
The appointment of Theodore H. Fri-
son as Systematic Entomologist in 1923
marked the beginning of a resurgence in
the faunistic activities of the Natural
History Survey. Until several years later
this move was felt primarily in the in-
sects, but eventually it spread to the other
animal groups. Frison’s first endeavors
were to collate the insect collections, but
his chief thoughts were aimed at meth-
ods for revitalizing the old charge to
publish a series of systematic reports
covering the entire field of the zoology
of Illinois (Illinois General Assembly
1885:23). Forbes was as anxious as
Frison to see this program begin. By this
time several factors had changed the
faunistic outlook considerably from that
of the beginning of the century. Good
roads reached almost every hamlet in the
state, and the automobile had supplanted
the train and buggy as a ready means of
travel. The ease of reaching all points of
the state made up in large measure for
the increasing destruction of large tracts
of native habitats and the necessity of
seeking primeval collecting spots in re-
mote and widely separated localities.
Taxonomically the picture had changed
to an equal extent, at least for insects.
In 1900 it was generally considered that
except in groups like aphids and ecto-
parasites, species could be readily identi-
fied by external characters through use
of, at most, a hand lens. Variation had
December, 1958 Ross:
been little recognized as a factor in and
a difficulty of identification. A reference
series of a few specimens was considered
thoroughly adequate for each species. Al-
though the value of series of specimens
was becoming recognized at the beginning
of the twentieth century, the true neces-
sity for larger population samples was
not fully recognized in insect groups un-
til about the 1920’s. By this time, in
group after group of insects and indeed
of other invertebrates, many of the older
species units were each being divided into
several species separated only by micro-
scopic characters, which were often
minute in character and difficult to see.
So detailed was the knowledge required
to identify many of these groups that it
was no longer possible for one person to
cover reliably the tremendous number of
groups which Hart had done so success-
fully according to the standards of his
day.
Influenced by these changes, a faunistic
program was evolved centering around in-
tensive studies of individual groups. The
program called for each staff member to
study some special group, collect material
throughout the state at different seasons
and in different habitats, identify the ma-
terial, and write up a report of the group
for Illinois. It was hoped that the serv-
ices of specialists at other institutions
could be obtained during the summer
months to work with Natural History
Survey personnel on Illinois reports. In
the original plan, the thought was that
these reports could be restricted quite
closely to Illinois material and to Illinois
species. This plan did in fact prove
satisfactory for the aphids and Orthop-
tera, which were relatively well known
for the country as a whole. When, how-
ever, projects were started for groups
which were poorly known for the conti-
nent, it was found essential to extend the
scope of the reports to cover roughly the
mid-central states, as Forbes had implied
as a general policy as early as 1900.
It was recognized early in this pro-
gram that many insect groups of little
importance economically were neverthe-
less of great importance ecologically. An
attempt was therefore made to develop
a program which would alternate the
treatment of groups having principally
FAUNISTIC SURVEYS 133
economic importance with those having
principally ecological importance.
Within the bounds of a_ primarily
systematic treatment, it was hoped that
basic information could be obtained on
the place of the species in nature. Collect-
ing programs therefore stressed discover-
ing the microhabitats, hosts, seasonal ap-
pearance, or other ecological attributes
of the different species.
An aim of great importance which de-
veloped for these reports concerned their
usability from the viewpoint of the be-
ginning student. Many keys made by
specialists contained language too tech-
nical to be readily understood by non-
specialists. Frison was acutely aware of
this fact and insisted that all keys in the
faunistic bulletins be couched in language
as simple as possible and that, wherever
helpful to an understanding of characters
or specialized terms, illustrations should
accompany the keys.
Frison’s plan for faunistic reports was
not put into operation until 1928, when
F. C. Hottes was employed during the
summer as a special appointee to work on
the aphids of Illinois. The appointment of
Hottes was the first of several of its kind.
In 1931, when Frison became Chief,
Herbert H. Ross became Systematic En-
tomologist. In 1935 the insect systematic
program became the Insect Survey Sec-
tion of the Natural History Survey.
The identification of economic insects,
always a duty of the Systematic Entomol-
ogist, became an important feature of
the Section. The Section was called on
also for the identification of certain other
invertebrates important in agriculture or
public health, especially mites, _ ticks,
aquatic Crustacea, and earthworms. In
these activities, changing taxonomic con-
cepts and the introduction of economic
insects and mites new to the state con-
tinually increased the difficulties of ac-
curate identification and the need for ob-
taining additional specialists for the staff.
In 1947 the faunistic program was
expanded to cover all animal groups, with
the idea of extending to groups other
than the insects the faunal survey aims
which had been developed for insects.
The Insect Survey Section was renamed
the Section of Faunistic Surveys and In-
sect Identification, and it became the
134
custodian of all the Survey’s taxonomic
collections of animal groups.
Over the years several artists have
contributed greatly to the utility and ap-
pearance of the Survey’s faunistic publi-
cations—Lydia M. Hart, H. K. Knab,
C. O. Mohr, Kathryn M. Sommerman,
and Elizabeth Maxwell. Miss Hart and
Dr. Mohr, especially, have graced Nat-
ural History Survey publications with a
multitude of remarkably fine total views
of insects.
RESEARCH COLLECTIONS
The great value of research and refer-
ence collections to programs in natural
history was stressed in the founding ar-
ticles of the Illinois Natural History So-
ciety and has been evident ever since in
all phases of applied ecology. The
Natural History Survey has therefore
stressed the assembling and maintenance
of adequate research collections of animal
groups as a corollary to its faunistic
activities.
The general aims in augmenting the
collections have varied over the years,
but in recent decades have approached
closely the policy expressed at the 1860
anniversary meeting of the Natural His-
tory Society and have emphasized first
the species found in Illinois and then
species or additional material from other
regions which contribute to analyzing or
interpreting the Illinois fauna.
Taxonomists in other institutions have
aided the Illinois Natural History Survey
greatly by identifying Survev material in
their respective specialties. This aid has
not only resulted in keeping the Survey
collection up-to-date but has afforded
needed reference material in many genera
or families.
Vertebrates
During the early periods of Survey
history, Forbes and his assistants built up
and maintained a large collection of IIli-
nois fishes, but kept only a small reference
collection of other groups. Much of the
fish collection is intact at present, but
the older material of other vertebrate
groups has become dissipated. In recent
decades emphasis has been placed on build-
ing up collections of amphibians and
Inuinois NATURAL History Survey BULLETIN
Vol. 27, Art. 2
reptiles, especially variational series from
Illinois and surrounding states; on start-
ing reference collections of birds and
mammals; and, more recently, on as-
sembling fish collections designed to be
a basis for a re-study of Illinois fishes.
Invertebrates Other Than Insects
In early records of the Survey, there is
no indication of the extent of invertebrate
collections other than that given by inci-
dental mention in a few small published
papers. The largest of these collections
comprised the molluscs; the aquatic spe-
cies were obtained chiefly from river sur-
veys and the extensive series of land spe-
cies from the collecting of Frank C.
Baker and Thural Dale Foster. Early
collections of other groups were made, at
least of phalangids, crustaceans, and cer-
tain protozoans, but only scattered vials
or slides of these materials are extant at
the present. Since 1930, special Illinois
collecting has been initiated for a few
groups, and in the pseudoscorpions and
ticks excellent Illinois series have been
assembled.
Insects
From the late 1870’s to the present,
the insect collections grew steadily. The
first official collection was Walsh’s pri-
vate collection purchased by the State for
Le Baron in 1870. Le Baron picked out
duplicates for a reference collection in his
office and then sent the main Walsh col-
lection to the Chicago Academy of
Sciences for safekeeping. There it was
destroyed in the Chicago fire of 1871.
Ironically, some of the material Le Baron
selected from the Walsh collection may
have persisted and be represented in the
present Natural History Survey collec-
tion. Since the extant Le Baron specimens
lack locality data, however, it is impos-
sible to determine their original source.
A collection of aphids made by Thomas
was preserved, also.
The insect collection which Forbes be-
gan in the State Laboratory was quite
small while he was at Normal. As soon
as he became established in Urbana in
1885, he started to place great emphasis
on building it up. About 5 years later
Forbes (1890:3) gave the following ac-
count of the collection:
|
December, 1958 Ross:
The entomological collection has been great-
ly enlarged, especially in Diptera, and a large
number of determinations in all orders have
been made. The named collection is now con-
tained in 160 double boxes, and numbers
about 5,000 species, each being represented,
as a rule, by four selected specimens. The
pinned and determined duplicate insects on
hand—largely in process of distribution to
public schools—amount to 42,600 specimens.
The alcoholic insects, including large numbers
of larvae, are contained in about 10,200 bot-
tles and vials.
Although we have no later estimates
of the size of this insect collection, it is
obvious from material now in the collec-
tion that by 1910 Hart was keeping much
larger series of each species.
In addition to material gathered by the
staff, in the Natural History Survey col-
lection are several collections of note that
have been given to or acquired by the
Survey. Notable items include the W.
A. Nason collection (insects of Algon-
quin, Illinois), the C. W. Stromberg
collection (insects of northwestern [lli-
nois), the Andreas Bolter collection (all
orders of insects), the Emil Beer Lepidop-
tera collection, the Charles Robertson
collection (insects on flowers), the L. J.
Milne caddisfly collection, the C. L.
Metcalf flower fly collection, the W. P.
Hayes weevil collection, the A. D. Mac-
Gillivray sawfly collection, the P. N.
Musgrave water beetle collection, and the
K. F. Auden beetle collection. Amateur
entomologists, such as Murray O. Glenn
of Henry and Alex K. Wyatt of Chicago,
have made numerous valuable additions
to the collection.
Because of special taxonomic interests
on the part of staff members, the collec-
tion is unusually comprehensive in certain
groups of insects. To this category be-
long the stoneflies, mayflies, and caddis-
flies; the aphids, mirids, and leafhoppers;
the leaf beetles, rove beetles, and June
beetles; the sawflies and bees; the thrips
and psocids; the springtails; and a few
groups of the true flies. In many orders
the collection contains a great deal of ma-
terial of the immature stages, which have
been emphasized in our reports. The
large collections of rove beetles, sawflies,
and ectoparasitic groups are associated
with plans for future projects.
Since 1925 primary types at the Nat-
ural History Survey have been segregated
FAUNISTIC SURVEYS 135
for reference and protection. In 1927
these represented about 1,000 species; the
number now stands at about 2,500 spe-
cies. At present the total insect collection
contains roughly 2,000,000 specimens, in-
cluding over 50,000 slide mounts, repre-
senting about 40,000 species and housed
in 2,700 insect drawers and 100,000
vials.
FAUNISTIC REPORTS
The preparation and publication of re-
ports on the animals of Illinois, a respon-
sibility repeated several times in mandates
to the Natural History Survey and its
predecessors, was begun with the first
publications of the Illinois Natural His-
tory Society and has been continued to the
present. Many of the first reports were
mere lists, often local in nature, and have
needed revision or complete retreatment.
In addition to the chiefly systematic
accounts outlined below, ecological and
economic studies over the years have con-
tained a wealth of records and descrip-
tions of a large number of species. This
is true especially of surveys of the sand
areas, prairie and forest areas, and exten-
sive bottom fauna and shore studies of the
large rivers.
Vertebrates
Faunistic reports have been published
on all the vertebrate groups occurring in
Illinois. Certain of the older reports are
now out-of-date because of our greatly
increased knowledge of the fauna.
Fishes.—The work on Illinois fishes
may truly be considered the first sustained
faunistic project carried on by personnel
of the Natural History Survey or its par-
ent organizations. The project was begun
with Forbes’ first connection with the
Illinois Natural History Society and con-
tinued as a cohesive systematic study until
1909.
At the time of birth of the Illinois Nat-
ural History Society, approximately three-
quarters of the I]linois fishes had been de-
scribed and named by such distinguished
early ichthyologists as Rafinesque, Le
Sueur, Girard, Agassiz, Mitchell, and
Kirtland. Half a dozen of these species
were first discovered in Illinois waters.
During the next three or four decades,
136
when Illinois waters were being studied
intensively by Forbes and his colleagues,
most of the remaining Illinois fishes were
described by such famous zoologists as
Jordan, Cope, Gilbert, Nelson, and
Forbes himself.
A regional list treating the fishes of the
Chicago area was prepared by Robert
Kennicott (1855), and comprehensive
catalogs of the fishes of the entire state
appeared in the first volume of the Bulle-
tin (Nelson 1876; Jordan 1878). Sev-
eral years later Forbes (1884) prepared
a third catalog of Illinois fishes, and early
in the present century Thomas Large
(1903) published a fourth list.
Some time in the 1870’s Forbes seems
to have developed the idea of producing a
well-illustrated and detailed account of
the Illinois fishes which would be useful
for all the Mississippi River states. Year
after year, wagon parties were sent to ex-
plore and collect in different streams of
the state until finally records were avail-
able for virtually every river and rill in
Illinois. Along the Illinois River large
collections were made year after year.
Some extensive collecting parties visited
localities in neighboring states. The
amount of human endeavor that went
into this project is monumental and rep-
resents the steadfast patience and toil of
30 years. The final report, The Fishes
of Illinois and its Atlas, by Forbes & Rich-
ardson (1908), summarized all this in-
formation and featured a remarkable set
of color plates prepared by Lydia Hart.
Since the appearance of the Forbes &
Richardson report, two other contribu-
tions have been made by the Natural His-
tory Survey to Illinois fish taxonomy. D.
H. Thompson & F. D. Hunt (1930)
published a report on the fishes of Cham-
paign County, and D. J. O’Donnell
(1935) published an annotated list of
Illinois fishes.
Birds.—Before 1858 there was an
abundance of illustrative and synoptic
references to North American birds by
Wilson, Nuttall, Audubon, and others,
and there were local lists of Illinois birds
by Robert Kennicott (1855) and H.
Pratten (1855). Later, R. H. Holder
(1861a) published a list of Illinois birds
and a short taxidermy manual in the
Transactions of the Illinois Natural His-
Intinois NarurAt History Survey BULLETIN
Vol. 27, Art. 2
tory Society. In 1881 Robert Ridgway
published a revised catalog and, a few
years later, two large reports, the two
volumes of The Ornithology of Illinois
(Ridgway 1881, 1889, 1895). The first
volume was destroyed by fire in the state
printer’s office and had to be completely
reprinted before it was issued. These two
volumes were among the pioneers in the
use of structural characters in keying the
birds of an area. Ridgway, a native of
Illinois, was not an employee of the state
but wrote these volumes because of his
intense interest in Illinois birds.
In later years Forbes, A. O. Gross, and
Frank Smith made many observations on
Illinois birds, but these studies were pri-
marily of an ecological nature.
Amphibians and Reptiles.—Survey
studies concerned with these animals did
not start until the 1880's. In the first vol-
ume of the Bulletin, N. S. Davis, Jr., &
F. L. Rice (1883) published a catalog of
amphibians and reptiles found east of the
Mississippi River. H. Garman (1890)
also studied these groups. No synoptic
collections were kept of the early ma-
terial. In the 1930’s Francis Lueth and
Willard Stanley accumulated records and
assembled several hundred specimens. In
the early 1940’s the Natural History Sur-
vey focused attention on these groups
through the co-operation of H. K. Gloyd
of the Chicago Academy of Sciences, C.
H. Pope of the Chicago Natural History
Museum, and H. M. Smith of the Uni-
versity of Illinois. In 1947 P. W. Smith
initiated an intensive study of these ani-
mals, making collections in all parts of
the state and plotting the variation and
distribution of each species. In 1957 this
project culminated in a comprehensive
report on the amphibians and reptiles of
Illinois; the report is now awaiting pub-
lication.
Mammals.—The Natural History
Survey and its parent agencies have pub-
lished only a small number of reports on
Illinois mammals. The first, by Cyrus
Thomas (1861), was published by the
Natural History Society. Early in the
present century, F. E. Wood (1910a)
published on the mammals of Champaign
County. In the 1930’s C. O. Mohr be-
came interested in the mammal fauna of
Illinois and gathered a great deal of in-
a
\
5
December, 1958 Ross:
formation on distribution and _ habits.
After Mohr left the Natural History Sur-
vey in 1947, the work on mammals was
taken up by D. F. Hoffmeister of the Uni-
versity of Illinois, and the resulting field-
book appeared shortly after Mohr had
rejoined the Survey staff (Hoffmeister &
Mohr 1957).
Invertebrates Other Than Insects
Most of the invertebrate studies made
during the early history of the Survey
concerned chiefly aquatic organisms which
were important in limnological inves-
tigations. ‘The first paper by Forbes
(1876) in the Bulletin was a list of the
Illinois Crustacea; this was followed by
a paper on Crustacea by L. M. Under-
wood (1886). A. Hempel (1896, 1899)
described a few rotifers and protozoans
from the Illinois River, and C. A. Kofoid
(1898, 1899) described a few plankton
organisms of Illinois. R. W. Sharpe
(1897), F. W. Schacht (1897, 1898),
and Ernest Forbes (1897) made addi-
tional contributions to a knowledge of the
Crustacea. C. M. Weed (1890) did con-
siderable work on the phalangids of I[lli-
nois and published a partial catalog of
the group.
Several other invertebrate studies pub-
lished in the Bulletin were almost en-
tirely the work of nonstaff members, some
of whom worked actively in co-operation
with the Survey. J. P. Moore (1901)
treated the Illinois leeches; Frank Smith
(1895-1928) published many papers on
earthworms; H. J. Van Cleave (1919)
studied Illinois River Acanthocephala;
Henry E. Ewing (1909) studied the
orobatid mites; and F. C. Baker (1906)
published a catalog of the Illinois Mol-
lusca.
Ecological work on the rivers amassed
collections of the various plankton groups,
but only those portions noted above were
ever analyzed taxonomically. Much of
the material was discarded after being
recorded, and much was lost by desicca-
tion. Except for the collections of Mol-
lusca, by 1947 only a small amount of
the early invertebrate collections — re-
- mained.
About 1930 a survey of the land snails
of Illinois was organized under the lead-
ership of F. C. Baker. The field work
FAUNISTIC SURVEYS 137
was done primarily by T. D. Foster.
Foster used a motorcycle on collecting
trips and shared with S. C. Chandler the
distinction of being one of the few mem-
bers of the Survey’s motorcycle brigade.
For 2 years he conducted a whirlwind
search over the entire state for land snails
and brought together a remarkable num-
ber of records. The material was iden-
tified by Baker, who prepared a report
that appeared as a fieldbook of the Illinois
land snails (Baker 1939). The book was
beautifully illustrated by C. O. Mohr.
Berlese collecting, instituted about 1933
primarily for exploring the insects in duff,
netted not only insects but large numbers
of terrestrial invertebrates, mainly arach-
noids. About 1940 C. C. Hoff of the
University of New Mexico became inter-
ested in co-operating in a study of pseudo-
scorpions of Illinois. He found that many
species collected in these Berlese samples
were new and represented a Midwestern
faunal element which had remained un-
seen because other pseudoscorpion §spe-
cialists lived in either the East or the
West. Hoff’s report on the Illinois fauna
was published by the Natural History
Survey (Hoff 1949).
Insects
Considering not only the economic im-
portance of insects but also the exceed-
ingly large number of species expected in
the state (approximately 20,000), it is
not surprising that the Natural History
Survey’s most extensive faunistic contri-
butions have been made in this group.
Many of the studies have resulted in de-
scriptions of new species, life history
notes, and distribution records contained
in short papers; many others have resulted
in comprehensive accounts of various
groups found in [Ilinois.
Orthoptera.—Thomas was early a
keen student of the Orthoptera and in the
first of the T'ransactions of the Natural
History Society published a list of this or-
der for Illinois (Thomas 18594). His in-
terest continued and he published a second,
enlarged list in the first volume of the
Bulletin (Thomas 1876). In the early
1900’s, Hart and A. G. Vestal made
large and extremely interesting collections
of this order in the Illinois sand areas, in
which an appreciable number of western
138 I_ttinois NATURAL History SuRVEY BULLETIN
species occur. In 1932 Morgan Hebard
of the Academy of Natural Sciences of
Philadelphia offered to prepare an account
of the Dermaptera and Orthoptera of
Illinois. For this project staff members
made additional collections in areas of the
state not previously covered for the group.
The report appeared 2 years later (Heb-
ard 1934).
Aphids.—This group was one of the
first emphasized in studies by the Natural
History Survey’s parent organizations.
Thomas, one of the leading early investi-
gators in the taxonomy of this group, pub-
lished a synopsis of one of the tribes and
described many new forms from Illinois
(Thomas 1878). About the same time
Nettie Middleton (1878) described an-
other species, and several years later C.
M. Weed (1891) published the results
of his studies on the life histories of a
number of species. Little more was done
with this group until J. J. Davis started
Vol. 27, Art. 2
further taxonomic investigation of the
aphids about 1908. In the Bulletin, Davis
(1913) published a commentary on the
Cyrus Thomas collection and in addition
20 papers on aphid taxonomy in various
entomological journals. Most of this
work he did while an assistant in the
State Entomologist’s Office.
In 1928 Frison and F. C. Hottes, the
latter now at Grand Junction, Colorado,
took up a study of Illinois aphids. This
was the first study to be based on a com-
bination of intensive collecting for one
group and opportunities for rapid travel
to all parts of the state. Field investi-
gations were made during the summers of
1928-1930. Each year collecting parties
started in the southern part of Illinois and
worked north and then reversed the pat-
tern so that each locality was collected at
different seasons. A complete set of slide
mounting equipment was taken into the
field, and temporary headquarters were
An Illinois Natural History Survey entomologist making field notes relating to insects he
has collected. The association of insects with their host plants is an important phase of the work
of Survey entomologists.
December, 1958 Ross:
set up in hotels at various towns. Each
party consisted of three persons. Usually
all three collected during the first half-
day spent in each locality; after that one
person stayed in the headquarters hotel
and mounted aphids while the other two
continued collecting. Lists of potential
hosts, with especially interesting ones in-
dicated, were used as a tick sheet in each
locality. About a hundred species, 36 of
them new to science, were added to the
state list. The report on this project was
published in the Bulletin (Hottes & Fri-
son 1931).
Odonata.—Nymphs of this order were
frequently encountered in limnological
work, and H. Garman and Hart reared
many of them during the 1880’s and
1890’s. This work set the stage for the
first report on Illinois dragonflies, an ar-
ticle by J. G. Needham & Hart (1903).
Later Philip Garman did much work on
the group and wrote an excellent account
of the damselfly suborder Zygoptera in
Illinois (P. Garman 1917).
Pentatomoidea.— This group includes
the stink bugs, a group of sucking insects
for which Hart had a special interest. He
assembled a remarkably fine collection of
the Illinois species and had virtually com-
pleted an account of the state fauna at the
time of his death. ‘The manuscript was
completed by J. R. Malloch and was pub-
lished in the Bulletin (Hart 1919). This
report was especially useful because it in-
cluded not only keys to the Illinois spe-
cies but also keys to the Nearctic genera.
Diptera.—The first serious work on
the flies done for the Natural History
Survey or a parent organization was by
J. R. Malloch. Although interested in
Diptera in general, Malloch specialized
in the Chironomidae or midges, of great
importance in the economy of Illinois
waters. He reared a large number of
these insects and was one of the first
workers to delve into the minute char-
acters of the male genitalia and the larval
mouthparts as an aid in species discrimina-
tion and identification. His rearings were
done chiefly in the vicinity of Havana
and Urbana, with a great deal of help
from Hart, who also collected adult ma-
terial from various parts of Illinois and
surrounding states. The report by Mal-
loch (1915) on the midges was outstand-
FAUNISTIC SURVEYS 139
ing among faunistic works. Not only did
it give equal emphasis to the adults and
larvae, a most unusual feature for the
time, but it benefited from two remark-
able faculties of Malloch’s. One was
Malloch’s ability to spot new characters
(dipterists agree that Malloch was a
genius at this not only in the midges but
in every group in which he worked).
The other was his ability to prepare un-
usually clear keys, which made his publi-
cations quite out of the ordinary in their
usefulness to other workers.
The breadth of Malloch’s interest in
Diptera was expressed when he published
in the Bulletin a classification of the
order based primarily on larval and pupal
characters (Malloch 1917). This study
was one of the first in which recognition
was given to the value of characters of
the immature stages in determining the
relationships of families within a large in-
sect order. Certainly it is a classic and
contains cogent ideas of fly classification
which even at this date have not been
fully incorporated into accepted classi-
fications of the order.
The next intensive Natural History
Survey work on Diptera was a study com-
menced by H. H. Ross about 1938 on the
Illinois mosquitoes. Because of restric-
tions on travel and lack of availability of
personnel during World War II, field
work and rearing progressed at a rela-
tively slow rate. The report on these in-
sects was published in the Bulletin (Ross
1947).
Plecoptera.—Although the Plecop-
tera or stoneflies are an abundant com-
ponent of many aquatic communities, no
state-wide taxonomic work on the Illinois
species was done until Frison became in-
terested in them in 1927. Previously
Walsh (1863, 1864a) had observed and
recorded many of the species occurring in
the vicinity of Rock Island. Frison and
another entomologist, R. D. Glasgow,
loved to hike and picnic, especially in the
hilly country along the Salt Fork River
south of Oakwood, Illinois. On fall ex-
cursions to this locality they noticed that,
in some of the very small streams, the
smallest of the stonefly nymphs kept in-
creasing in size as winter approached.
This observation excited Frison’s curios-
ity and from it arose an abiding interest
140 Ittinois NaruraAL History SurRvEY BULLETIN
in and love of stoneflies which continued
through the rest of his life. Frison fol-
lowed the development of these little
stoneflies, which proved to be the small
group called winter stoneflies. He discov-
ered that little was known concerning
the fauna of the Midwest and began a
study of the group for Illinois. The first
report on stoneflies treated a few small
families comprising the winter stoneflies
(Frison 1929).
The collecting and rearing of species
of the other families in the order were
begun. Rearing these insects proved to
be difficult because the laboratory water
available at Urbana did not sustain the
stoneflies. Copper cages on a raft placed
in a stream were eventually devised to
overcome this difficulty, but the losses of
these expensive cages by vandalism finally
proved so great that the practice was dis-
continued. A considerable number of
species were reared from emerging
nymphs caught at the water’s edge. By
one means or another, all the Illinois spe-
cies were finally reared. Six years after
publication of the winter stonefly report,
a report covering all the Illinois Plecop-
tera appeared (Frison 1935).
Frison found sets of nymphal charac-
ters which appeared to have great prom-
ise for indicating natural groupings of
the species and genera, indications such
as Malloch had previously found when
exploring characters of the larvae and
pupae of Diptera. The studies of stone-
fly nymphs set the stage for what might
be called the modern classification of the
order and stimulated emphasis on the
study of immature stages in subsequent
Survey projects on several other orders
of insects.
These insects proved so fascinating that
Frison’s studies did not long stop at the
boundaries of Illinois. Through material
obtained on vacation trips and at other
opportunities, the stonefly collection was
enlarged to cover all of North America.
With large series available from diverse
areas of the continent, it became apparent
that many of the old species were in real-
ity species complexes, and as a result
many of the Illinois populations had to
be described as new. The results of these
latter developments in the stoneflies were
published in the Bulletin (Frison 1937,
Vol. 27, Art. 2
1942a) and as shorter papers in various
entomological journals.
Megaloptera.—These, the alderflies
and dobsonflies, were collected during the
aquatic work on stoneflies and caddis-
flies; some specimens were received from
fishermen who had encountered them
along streams and had sent them in for
identification. Attempts to identify these
Megaloptera by means of then current
literature proved unsatisfactory. In the
alderfly genus Sialis, characters noticed
in the male genitalia seemed to provide
an excellent means for positive determina-
tion of the species and an analysis of these
characters led to a re-evaluation of the
species in the genus, many of which
proved to be new. About half a dozen
species were found in the material from
Illinois and surrounding states. As part
of an effort to learn something of the en-
tire distribution pattern of the Illinois
species, the study was extended to cover
the fauna of the whole continent. The
report on this study was published in the
Natural History Survey Bulletin (Ross
1937).
Miridae.—As the aphid project was
coming to a close, H. H. Knight of lowa
State College agreed to work summers
with the Illinois Natural History Survey
and prepare a report on the Miridae or
plant bugs of Illinois. Knight was on the
Survey payroll for three summers. Pre-
viously Hart had assembled and identified
an excellent collection of this group for
the state, but since Hart’s time Knight
had shown that characters of the genitalia
indicated a much larger fauna than ear-
lier workers had suspected on the basis of
the external characters they used.
The mirid field trip pattern followed
that of the aphids, with the trips around
the state scattered through the different —
seasons. Again host collecting was em-
phasized, and field headquarters were set
up locally in hotels. The general plan
was to collect until about 3 o’clock in the
afternoon, and then pin up the day’s
catch. With the Miliridae, this was
thought desirable because of the fragile
nature of certain diagnostic characters,
especially pubescence, which might be
brushed off if the specimens were relaxed
and pinned later. Many thousands of
specimens were collected each year, and
December, 1958 Ross:
again a large number of species, including
about 20 new ones, were added to the
state list. Members of the staff served as
“ouinea pigs” to try out the keys, to point
out spots difficult for the uninitiated, and
to suggest improvements. Mohr did his
usual excellent job in providing many
total views of various species. “The report
resulting from this project was published
in the Bulletin (Knight 1941).
Ephemeroptera.—The mayflies were
early recognized as being one of the most
important components of the fresh-water
biota of Illinois, but, except for early
local studies by Walsh (1863, 18640), lit-
tle was done concerning their systematics
in this state until about 1925. At that
time collections were sent to J. W. Mc-
Dunnough at Ottawa, Canada, who iden-
tified a considerable amount of material.
Collecting and rearing of species in the
order were only sporadic until about
1937, when B. D. Burks, assigned to the
project, began an intensive field program.
Certain genera of the mayflies proved
dificult to rear because the subimagoes
seldom survived in cages, and in some
species the nymphs did not molt to the
subimaginal stage in still water. For these
genera Burks worked out a neat con-
trivance. He placed fully mature nymphs
(which emerge at night) in a pan of
water containing a large stone, placed the
pan on the floor of a car at nightfall, and
had the car driven over a gravel road. The
wave action produced in the pan by the
rough ride broke the surface film enough
so that the nymphs could emerge. As the
driver guided the car along the road,
Burks sat in the back seat and periodically
examined the pan with a flashlight; he
captured each subimago as it emerged,
put it in a vial for emergence to imago,
and associated the cast skin with it.
The extremely short period of adult
emergence of many species frequently
necessitated camping out along a stream
and keeping an around-the-clock vigil for
emergence. During one summer a rear-
ing station was established at a_ fish
hatchery along Nippersink Creek, in the
-extreme northeastern part of the state,
which is especially rich in mayfly species.
A flash flood inundated the rearing
rooms and nearly swept away the sum-
mer’s material. ‘The material was _res-
FAUNISTIC SURVEYS 141
cued as the vials were beginning to float
out of the window in the shoulder-deep
water.
At first, Burks had difficulty obtain-
ing good series of imagoes, although the
subimagoes could be collected in quan-
tity at lights. Burks found that he could
catch great quantities of these sub-
imagoes in paper bags, turn them loose
in his hotel room, and have them emerge
in fine shape, so that any desired number
of imagoes could be secured.
When Burks left the Natural History
Survey in 1949, he had completed the
mayfly report, which was published in
the Bulletin (Burks 1953).
Cicadellidae.—About 70 years ago,
C. W. Woodworth (1887) published
a short treatment of this family, com-
prising the leafhoppers, and later Hart
and Malloch made extensive collections
of these insects, some of which were
identified and recorded by W. L. Mce-
Atee of the United States Biological
Survey (McAtee 1924, 1926). Malloch
himself (1921) wrote a short paper on
the group.
In 1934 D. M. DeLong of Ohio
State University agreed to tackle the
job of working up a more extensive
treatment of the leafhoppers of Illinois.
A few years prior to 1934, DeLong had
begun an investigation of the male
genitalia in the leafhoppers and found
that, as in a number of other groups,
many of the species previously identified
on the basis of external characters were
in reality clusters of species which could
be separated primarily on the basis of
genitalic structures. Both in North
America and elsewhere the discovery of
these characters had set off a tremendous
burst of activity by leafhopper workers
to explore these structures. It was in
the midst of this burst of effort that the
Illinois project was launched. DeLong
and other staff members spent almost all
of the next three summers crisscrossing
Illinois and collecting leafhoppers in
the various habitats of the state. During
rainy weeks and also during the winter
back in Columbus, Ohio, DeLong iden-
tified these collections and continued his
revisional studies. Various members of
the staff made special collections as in-
dicated by new taxonomic discoveries.
142
By 1945 it was apparent that a re-
port embracing all the leafhoppers un-
der one cover was impractical, and De-
Long prepared the manuscript for about
half of the fauna, which included all
the subfamilies except the Cicadellinae.
This report was published in the Bulletin
(DeLong 1948).
At this time, R. H. Beamer of the
University of Kansas had drawn atten-
tion to the tremendous number of Muid-
western species contained in the genus
Erythroneura, the largest genus of the
untreated subfamily Cicadellinae. Mrs.
D. J. Knull had identified a large part
of the Natural History Survey material
in this genus. Most of the several hun-
dred species were known only from hi-
bernation collections, and it was felt
that, before proceeding with the manu-
script on this subfamily, the host rela-
tionships and other ecological informa-
tion should be ascertained for these
species. As a result the project was re-
aligned and a new host-collecting pro-
gram for the entire subfamily was dele-
gated to the faunistic staff of the Survey.
The large number of host associations al-
ready established have proved of interest
in contributing ideas concerning evolu-
tionary problems in insects having moder-
ately rigid host associations.
Trichoptera.—A study of the caddis-
flies was prompted by the importance of
this group in the economy of IIlinois fresh-
water habitats. The project was planned
originally as a joint one with Dean Cor-
nelius Betten of Cornell University, who
had in manuscript at the time the first
comprehensive and useful New World
faunistic study of the group; his study
dealt with the fauna of New York. Bet-
ten in America and A. B. Martinov in
Russia had pioneered in the technique of
clearing the male genitalia of Trichoptera
in KOH in order to get a more exact
knowledge of these diagnostic structures.
Betten spent 6 weeks on the II]linois Nat-
ural History Survey staff in the summer
of 1931, his time being spent partly on
collecting trips around the state and
partly in identifying the caddisfly ma-
terial in the Survey collection. In 1932
press of other duties caused Dean Betten
to retire from the project, which was then
assigned to Ross.
Ituinois NATuRAL History SuRVEY BULLETIN
Vol. 27, Art. 2
Much of the caddisfly collecting was
done as an adjunct to stonefly, mayfly,
mirid, and leafhopper collecting, but spe-_
cial trips were made to springs and cer
tain rivers, such as the Kankakee, which —
supported unusual species. As the taxo-—
nomic analysis of the material progressed,
it became evident that the Illinois fauna
differed in remarkable fashion from
that of the only other state for which it
was well known, New York. As a result, —
it was necessary to practically revise the
entire North American fauna before the
7
Illinois groups could be satisfactorily
segregated to species. This was true espe-_
cially in the family Hydropsychidae and
the so-called microcaddisflies, the Hydrop- —
tilidae. As with the other aquatic groups, —
an effort was made to rear the species and —
associate larvae and pupae. Some of this —
work was done with rearing cages, but
the greater part was accomplished by as-
sociating mature pupae with their corre-
sponding larval parts in the cocoon or
case. The report of the Illinois fauna of
this order, including keys to the adults
and immature stages, was published by
the Natural History Survey (Ross 1944). —
After this report appeared, some ac-
tivity relating to the Trichoptera was
continued, primarily centered around at-
tempts to reconstruct the origin of groups
and the dispersal patterns which led to
the formation of the present Illinois
fauna. As genera and families from other
parts of the world were studied, it was
possible to get a better understanding of
the classification and evolution of the or-—
der. It is reminiscent of Malloch’s and
Frison’s work in the Diptera and Ple-
coptera that the immature stages were
found to hold the principal key to deduc-
ing the evolution of the group. ‘These
studies made possible the publication of
the book Evolution and Classification of
the Mountain Caddisflies (Ross 1956).
Coleoptera. — The beetles have fre-
quently been the subject of intensive study
by the Natural History Survey staff.
Early in the history of the organization,
extensive rearing was done, and volumes —
of important information on this work
are scattered through the State Entomolo-
gist’s reports. The first extensive Illinois
publication on the order was by Le Baron
(1874) who, in his fourth report as
p
Kaila nt ete te pl tet till
eS a a. ee
———-
December, 1958 Ross:
State Entomologist, published an outline
of the Coleoptera of Illinois, with keys to
genera and notes on many species.
The next serious study of the order
concerned the genus Phyllophaga, the
June beetles. The larvae of these beetles
were extremely serious pests, and before
1890 Forbes and his assistants set about
making systematic collections of the genus
throughout the state. Forbes (1891) pub-
lished a survey of the Illinois June beetles ;
the publication included keys to the spe-
cies written by Hart. R. D. Glasgow
(1916) reviewed this material and pub-
lished a synopsis of the synonymy and the
description of a new species. Shortly
after, J. J. Davis made a detailed study
of the ecology of Phyllophaga and also
became interested in their taxonomy. The
study resulted in one fine paper on the
natural enemies of June beetles and in
another describing new forms. These two
papers appeared in the Bulletin (Davis
1919, 1920). Glasgow continued his in-
terest in the genus, but subsequently pub-
lished only one or two small papers on
the subject.
In 1944 another beetle project was in-
augurated, this one on the leaf-feeding
beetles, or Chrysomelidae, with M. W.
Sanderson as the investigator. The be-
ginning of the leaf beetle investigation
was based on a need for supplying cor-
rect names for various species of economic
importance to Illinois crops. Early at-
tempts at identification disclosed that
much of the older literature on the fam-
ily was unreliable, and diagnosis of spe-
cies often was uncertain. Not only were
there deficiencies in the literature; few
attempts had been made in North Ameri-
ca to relate larval and adult morphology
for generic or species diagnosis. “The proj-
ect for Illinois was organized along the
lines of earlier faunistic studies. Collec-
tions were made throughout the state,
with special emphasis on securing host-
adult-larval associations. At present a
report embracing two-thirds of the sub-
families and including about a half of the
Illinois species is nearing completion, and
_a large proportion of the field work for
other subfamilies is in an advanced stage.
Thysanoptera. — Survey activity re-
lating to this order of little insects, the
thrips, had its beginning about 50 years
FAUNISTIC SURVEYS 143
ago; J. D. Hood (1908) published a
paper describing a group of species from
Illinois. Late in the 1930’s, when Berlese
sampling was started in the Survey, inter-
est in this group was again aroused be-
cause of the large number of specimens
and variety of species which appeared in
the collections from moss and leaf mold.
In 1947 L. J. Stannard planned a com-
prehensive faunistic study of the order for
Illinois. Many difficulties were encoun-
tered, including the inaccessibility of
critical types, difficulties in finding satis-
factory mounting media, and difficulties
in interpreting existing keys and descrip-
tions. The genera were especially poorly
defined and inconsistently used, and be-
fore satisfactory names could be estab-
lished for the Illinois species it was neces-
sary to embark on major studies in the
general classification of the group. The
results of one of these studies, investigat-
ing the generic categories in the suborder
‘Tubulifera, were published by the Uni-
versity of Illinois (Stannard 1957). As
a consequence of all these factors the IIli-
nois study of this group has come close
to a treatment of the thrips for half the
continent. Intensive collecting in all con-
ceivable situations and at different sea-
sons has brought to light large numbers
of new state records. A report on these
insects for Illinois is in an advanced state
of preparation.
Lepidoptera.—As mentioned earlier,
in his first report Le Baron (1871) de-
scribed a new species of moth. Since that
time a great deal has been written, espe-
cially in the State Entomologist’s reports,
on the moths of Illinois. Most of this
material, however, is in the form of small
contributions on the descriptions of spe-
cies, their larvae, or their habits. How-
ever, Thomas (1881), with the assistance
of Nettie Middleton and John Marten,
published a synopsis of lepidopterous
larvae for Illinois. This report included a
similar synopsis by D. W. Coquillett
(1881). Later, Forbes and his assistants
prepared keys to certain economic spe-
cies, and W. P. Flint & Malloch (1920)
published in the Natural History Survey
Bulletin a paper on the European corn
borer and related species.
In 1955 R. B. Selander began a fau-
nistic project designed to cover many of
144 Ituinoris NatrurAL History SurvEY BULLETIN
the families of small moths or micro-
lepidoptera, which were poorly known in
Illinois. The Blastobasidae were chosen
as the first family for study because the
genitalic structures of the Nearctic spe-
cies had never been investigated. Selander,
now with the University of Illinois, as-
sembled large quantities of Illinois mate-
rial and unearthed a diagnostic set of
characters in the genitalia. Work on this
project is continuing.
Hymenoptera.—Aside from rearing
and describing a few parasites and saw-
flies, the Natural History Survey staff has
done only one serious piece of work on
the Illinois Hymenoptera fauna. This was
a study by Malloch (1918) on the genus
Tiphia.
Collembola.—Although among the
most abundant insects numerically, the
Collembola or springtails were not
stressed until 1928, when large collections
were made in various parts of the state
and sent to J. W. Folsom, U. S. Depart-
ment of Agriculture, for identification.
When Folsom died, the project reverted
to simply a collecting program. Subse-
quently, Berlese sampling added large
quantities of these insects to our series.
The project was revitalized when H. B.
Mills joined the Natural History Survey
in 1947; since that time steady progress
has been made on a study of this group
for I[]linois.
RETROSPECT AND
PROSPECT
In following the objectives set forth in
the original organization of the Illinois
Natural History Survey, the faunistic
program performs three principal func-
tions pertaining to the animals of I]linois
—assembling and maintaining research
and reference collections, preparing re-
Vol. 27, Art. 2
ports on the various animal groups, and
identifying economic species. At times the —
program has emphasized one function —
more than another, but over the years —
steady progress has been made in all three —
departments. .
Today the taxonomic methods by —
which these functions are achieved are
far more complex and_ time-consuming —
than they were when the program was —
started. If transplanted to today, the fau-
nistic worker of 1858 would doubtless be
astonished at changes in the species con- —
cept, in taxonomic techniques, in micro-
scopic and other equipment, and at the
great increase in recognized invertebrate —
species and genera.
As these complications have developed, —
it has become clear that there is no easy —
short cut in making an adequate survey
of an animal group for Illinois. Each re- —
port represents a great deal of collecting
and study over a period of years.
Members of other sections of the Nat-
ural History Survey have aided the fau-
nistic program immeasurably by rearing —
and collecting material, identifying host —
or indicator plants, editing reports, and —
assisting with library problems. Taxono-
mists in other institutions have been of —
great aid not only by publishing papers —
of inestimable use in studies of Illinois
species, but also by assisting in many other
ways with specific problems.
It is a tribute to the founding fathers
of the Illinois Natural History Society
that certain of their general principles
were and still are remarkably good guides
for a faunistic program. The importance ~
of combining systematics and ecology and
of having a broad geographic scope for
reference collections becomes more ap- —
parent as new discoveries help unravel the
complex faunal relationships of Illinois —
species.
Applied Botany and Plant Pathology
HEN the Illinois Natural History
Society was organized in 1858 to
promote the advancement of science in the
state, botany was a major field of interest
of several of its founders.
The earliest reported botanical research
in Illinois was the study of flora in south-
ern Illinois by André Michaux (Sargent
1889), a distinguished botanist of France.
In 1795 Michaux traveled from the Ohio
River up the Wabash River to Vincennes,
Indiana. He crossed I]linois to Kaskaskia,
August 23-30, to Prairie du Rocher, Sep-
tember 5—6, and returned to Kaskaskia,
September 8-9. On October 2, he started
toward the Ohio River and arrived at
Fort Massac on October 8. Later he re-
turned to Kaskaskia, Fort Chartres, and
Prairie du Rocher and started on his re-
turn from southern [llinois on December
14.
Following Michaux and during the
first half of the nineteenth century, many
physicians and amateur botanists studied
and reported on the flora of Illinois. Dr.
Lewis C. Beck (1826a, 1826), 1828),
in publishing his contributions to the bot-
any of both Illinois and Missouri, listed
65 plants in the prairies near St. Louis
and 14 in barrens. Also, he reported on
his studies of plants along the [Illinois
River bluffs near St. Louis. A catalog of
plants collected in Illinois by Charles A.
Geyer was published with critical remarks
by Dr. George Engelmann (1843) of St.
Louis, Missouri. Dr. C. W. Short (1845)
of Louisville, Kentucky, reported on his
observations and collections of the flora
of prairies of Illinois as a result of his
extensive travels in several sections of the
state. Dr. S. B. Mead (1846) prepared
a catalog of plants growing in Illinois,
most of them growing near Augusta in
Hancock County; this work was _ pub-
lished in the Prairie Farmer. Dr. Mead
‘mentioned the habitats of the plants he
included in his catalog. Also, he listed the
uses of the plants, including those used
by dyers and coopers, those used for
hedges, chair bottoms, hay, ornamentals,
Te. DRC CAR rR
edible fruits, common tea, and medicine,
those known to be poisonous, and those
known to be troublesome weeds. The year
before the Illinois Natural History So-
ciety was founded, I. A. Lapham (1857a)
published a catalog of the plants of Ili-
nois; his catalog included lists con-
tributed by Mead and Engelmann. In pre-
paring the catalog, Lapham examined the
extensive collections of plants made by
Robert Kennicott, Emile Claussen, and
others.
Mead’s list, as mentioned above, com-
prised plants principally in the vicinity of
Augusta in Hancock County. Engel-
mann’s list comprised plants in southern
Illinois, especially in the vicinity across
the Mississippi River from St. Louis, Mis-
souri. Dr. Mead, Lapham (1857a:494)
wrote, “has probably devoted more time
and labor to the examination of Illinois
plants than any other botanist, and _ his
collections now form part of most of the
principal herbaria of the world.”
Lapham emphasized that catalogs of
plants were useful to farmers, physicians,
horticulturists, botanists, cabinet makers,
wheelwrights, and other workers in wood
because these catalogs listed plants of in-
terest to each group; his catalog listed
1,104 species representing 111 orders of
plants. From a geographical point of
view, Lapham divided Illinois into three
districts: (1) the heavily timbered tracts,
mainly in the southern portion of the
state, and the “groves” or detached bodies
of timber surrounded by prairies, in the
middle and northern portions of the state ;
(2) the open prairie tracts of 1 to 20
miles in diameter and destitute of trees;
(3) the tracts of “barrens,” intermediate
between the prairie tracts and the tim-
bered tracts. The barrens appeared to be
in transition from open prairies to densely
timbered tracts. They were sparsely cov-
ered with several species of oak trees and
with dense undergrowth of shrubs and
annuals.
Treatises on plant material, published
in the Illinois State Agricultural Society
[ 145]
146
Transactions for 1856-1857, indicated the
rapidly increasing interest in applied
botany. These treatises, presented by O.
Ordway (1857) of Lawn Ridge, H. L.
Brush (1857) of Ottawa, Samuel Ed-
wards (1857) of La Moille, J. P. Eames
(1857), Dr. Frederick Brendel (1857)
of Peoria, and I. A. Lapham (18570) of
Milwaukee, Wisconsin, dealt with sev-
eral phases of research, including culture
and cultivation. The types of plants
studied were evergreens, flowers, grasses,
grain fruits, and vines.
At La Moille, Edwards started plant-
ing evergreens in 1845 and, by 1857, had
planted more than 125,000 plants ob-
tained from forests of Minnesota, Wis-
consin, Michigan, Indiana, Ohio, New
York, and upper Canada and also some
obtained from eastern and European
nurseries—in all, more than 25 species
of evergreen plants. He was most favor-
ably impressed with the growth of Nor-
way and black spruces, Austrian, Scotch,
and white pines, and balsam fir. Siberian
and American arbor vitaes and red cedar,
he found, were excellent for screening.
Other species he mentioned that suc-
ceeded well in this climate and soil were
Irish, Swedish, and savin junipers, red
spruce, and a variety of pine from Ten-
nessee. Hemlock was subject to winter
injury; Douglas spruce, cedar of Leba-
non, deodar cedar, silver fir, English and
Irish yews, Himalayan and Araucarian
pines, and Chinese arbor vitae did not
survive the winters. In 1857 Dr. Cyrus
Thomas, with the help of S. Burtley,
started studying the flora of the Murphys-
boro region of southern Illinois (Thomas
1857).
EARLY ACTIVITIES
Among the persons interested in botany
who were active in organizing the Illinois
Natural History Society were M. S.
Bebb, Dr. Frederick Brendel, E. Hall,
Robert Kennicott, Dr. S. B. Mead, Dr.
Cyrus Thomas, and Dr. George Vasey.
Much of the information obtained by
them on the flora of Illinois was pub-
lished in the Illinois Natural History
Society Transactions. When the original
purpose in organizing the Natural His-
tory Society was set forth as the advance-
Inurinois NAturRAL History SurvEY BULLETIN
ment of science, botany was mentioned
along with entomology and geology. In
succeeding years special interests de-
veloped in the field of botany, as indicated
by the published works of Brendel, Bebb,
Vasey, Thomas, Edwards, G. W. Minier,
Henry W. Bannister, and H. H. Bab-
cock from 1859 to 1887, most or all of
whom were members of the Natural His-
tory Society. Brendel was a_ prolific
worker and was the author of numerous
articles published over a period of nearly
30 vears (Brendel 1859a, 18594, 1859c,
1859d, 1860, 1861, 1870, 1876, 1887).
These articles included information on
the flora of Peoria and other areas of the
state. Brendel was interested in shrubs
and forest trees, especially the oaks. Also,
he wrote on rare plants in the state and
on a peculiar growth of the water lily.
It is significant that an article by him,
“The Tree in Winter,” was one of the
first articles published in the Bulletin of
the Illinois State Museum of Natural
History.
Bebb (1859) published a list of 44
species of plants occurring in the northern
counties of the state; his list was an addi-
tion to the catalog by Lapham (1857a).
Vasey’s interest in different phases of
botany is indicated by his papers (Vasey
1859, 1861, 1870a, 1870b). Among these
reigagal
Vol. 27, Art. 2m
papers were studies on flora, including —
mosses of the state and maritime plants
of the Great Lakes and interior regions;
also, descriptions of two plants new to
Illinois.
When Thomas (186lc) proposed a
plan for a natural history survey of IIli-
nois, he suggested that this survey include
a systematic cataloging of the flora and
2
fauna of the state and that the data be —
published so that the same work would
not need to be repeated by others. Ban-
nister (1868) described prairie and forest
plants of Cook County, and Babcock
(1872) described the flora of the Chicago —
area. John Wolf and Elihu Hall prepared
a list-of mosses, liverworts, and lichens
of the state. This list, which was pub-
lished in the Bulletin of the Illinois State
Laboratory of Natural History, contained
115 genera and 386 species (Wolf &
Hall 1878). Wolf was on the staff of the
State Laboratory of Natural History in
1880.
December, 1958
By 1865 concern was voiced that trees
of the state were being used so rapidly
for lumber that cultivation and planting
of trees should be promoted. Minier
(1865, 1868) published two articles on
the cultivation of forest trees. In his sec-
ond article Minier (1868:279) stated:
“Tree planting in I]linois is no longer for
ornament merely. It has become a neces-
ey... |. If, then, the coming genera-
tions are to be supplied with timber, the
present must plant it for them.” Edwards
(1868) recommended planting trees but
pointed out that black locust trees that
had been planted 25 years earlier had
been seriously damaged by borers.
Specific interest in some specialized
groups of plant life in Illinois became
evident shortly after 1870, as indicated
by the works of Thomas J. Burrill on
plant diseases caused by fungi and bac-
teria. Burrill, on the staff of the Illinois
Industrial University, the University of
Illinois, and the Illinois State Laboratory
of Natural History, was a close associate
of Stephen A. Forbes for 27 years. He
reported on fungus diseases in the 1870’s,
especially on fungi which cause diseases
of vegetable and fruit crops (Burrill
1874, 1876, 1877). Later he reported
that the widespread blight of pear trees
was caused by a bacterium (Burrill
1881). This, the first report that bacteria
cause plant diseases, opened up a new
field of research. Burrill continued to
publish articles on fungi and_ bacteria
that cause plant diseases and in 1885 he
published a 115-page article, in the Bul-
letin of the Illinois State Laboratory of
Natural History, on the parasitic fungi
of Illinois (Burrill 1885).
Following 1885 botanical research ex-
panded in scope to include all types of
native and naturalized plants in the
state. The work of Burrill while on the
staff of the Illinois State Laboratory of
Natural History from 1885 to 1892 in-
dicates the expanding development of
botanical interest in forest trees and dis-
eases of crop plants. Burrill prepared
papers not only on fungal and bacterial
diseases of crop plants but also on forest,
roadside, and street trees, biology of silage,
and extermination of the Canada thistle
(Burrill 1886, 18875, 1887c, 1888,
1889a, 1889, 1890). Among others em-
Carter: APPLIED BOTANY AND PLANT PaTHOLOoGy 147
ployed as botanists on the staff of the
State Laboratory of Natural History were
Rachel M. Fell, Arthur B. Seymour,
Benjamin M. Duggar, and Arthur G.
Vestal.
A well-illustrated, 142-page article on
edible and poisonous mushrooms in IlIli-
nois, prepared by Walter B. McDougall
(1917), was published in the Bulletin of
the Illinois State Laboratory of Natural
History. This article contains many
plates illustrating the mushrooms de-
scribed and is exceedingly useful in dif-
ferentiating between poisonous and edible
mushrooms.
Studies on plankton were carried on by
C. A. Kofoid from 1895 to 1900 and by
Samuel Eddy from 1925 to 1929. Ko-
foid’s extensive work on the plankton of
the Illinois River was published in the
Bulletin of the Illinois State Laboratory
of Natural History (Kofoid 1903, 1908).
Eddy’s work dealt with plankton of Lake
Michigan, the Sangamon River, and some
sinkhole ponds in southern Illinois; this
work was reported in the Bulletin of the
Illinois Natural History Survey (Eddy
1927, 1931, 1932).
Interest in the ecology of vegetation
and plant associations of sand prairies in
Illinois is indicated by the papers of C. A.
Hart and H. A. Gleason (Hart & Glea-
son 1907; Gleason 1910), F. C. Gates
(1912), and Vestal (1913) published in
the Bulletin. Information was obtained
not only on the general plant associations
but also on the physical environment, the
blow-out formations, the blow-sand com-
plex, the blackjack oak associations, and
some adaptations of the plants to the en-
vironment.
Although Minier (1865, 1868) and
Edwards (1868) were concerned about
the rapid destruction of trees in the
1860’s, it was not until 1911 that a policy
on forest management was recommended
by R. C. Hall and O. D. Ingall. In an
article on forest conditions in Illinois,
published in the Bulletin (Hall & Ingall
1911), they recommended (1) adoption
of an adequate state fire-protection sys-
tem, (2) inauguration of an education
campaign for scientific and practical forest
management, and (3) further investiga-
tion of the forest problems involved and
development and extension of wood lots
148 Ittinois NarurAL Hisrory Survey BULLETIN
in the state. Also, they proposed a forest
law for the state. Later, Forbes and Rob-
ert B. Miller (Forbes 1919a, 1919);
Forbes & Miller 1920) pointed out that
the forests of Illinois were being rapidly
destroyed and that only very few of the
remaining forests were being properly
handled. Miller (1923) made the first
extensive report on a survey of the forests
of Illinois; the report was published in
the Bulletin of the Illinois Natural His-
tory Survey.
classification ; history and types of forests
and important trees in the forests; uses
of forest trees in milling and logging op-
erations, wood-using industries and veneer
industries; production of charcoal, ties,
and mine timbers; and adverse effects of
fires, erosion, and grazing on forested
areas.
The second extensive report on a forest
survey of Illinois was made by Herman
H. Chapman and Miller and published
in the Bulletin (Chapman & Miller
1924). In this report the economic value
of the forests and the forests as a crop
were emphasized. The uses made of forest
trees were discussed, and a policy of
proper management of the forests to pre-
vent the continued decimation of timber
was outlined.
C. J. Telford (1923), a Natural His-
tory Survey forester, reported on height
and growth studies on certain bottomland
tree species in southern Illinois. He found
that naturally stocked plantings of syca-
more, cottonwood, pin oak, and maple
produced better growth than did plant-
ings of most other species in the bottom-
lands.
Telford (1926) reported on the third
forest survey of Illinois. In this report,
which included descriptions of the forests
in the state and data on growth of in-
dividual trees and yields of different types
of trees, he reviewed the proposed forest
policies given in the two previous forest
surveys of the state and urgently recom-
mended setting up an educational pro-
gram to promote the development of
farm wood lots, the protection of the
then present forests, and the reforestation
of much of the waste land, estimated to
total 1,577,663 acres.
These reports on forests of Illinois
stimulated interest in the preservation and
The survey covered land
Vol. 27, Art. 2a
expansion of the forest resources of the
state. A forestry program was carried on
and expanded by the extension foresters
who succeeded Telford and who were
employed jointly by the Natural History
Survey and the Department of Forestry
of the University of Illinois. They were
L. E. Sawyer, J. E. Davis, and Li Bp
Culver. Since 1954 the Natural History
Survey has not participated in this for-
estry program.
By 1900 special emphasis was being
directed toward control of plant diseases
in Illinois. This trend was emphasized
by some of Burrill’s papers, such as that
on spraying for the control of bitter rot
(Burrill 1903). As interest in this field
continued to increase, it became evident
that a systematic study of plants and
plant diseases in Illinois should be inau-
gurated. In 1921 a botanical section was
established within the framework of the
Natural History Survey by the appoint-
ment of Leo R. Tehon as the first
botanist.
Under the direction of Tehon as bot-
anist in charge of the Section of Botany
from 1921 to 1935 and as botanist and
head of the Section of Applied Botany
and Plant Pathology from 1935 until his
untimely death in 1954, botanical re-
search expanded to include work not only
in the field of general botany but espe-
cially in the fields of mycology, plant
pathology, and taxonomy. The number of
technically trained scientists on the staff
was increased from | in 1921 to 10 in
1954.
Tehon’s broad background and train-
ing and his mastery of the various fields
of research carried on in the botanical —
section are indicated, in part, by his many
and varied publications. Tehon described
many new genera and species of fungi,
most of them in a series of six articles
under the title “Notes on the Parasitic
Fungi of Illinois’ (Tehon 1924, 1933,
1937b; Tehon & Daniels 1925, 1927;
Tehon & Stout 1929). Also he wrote
“A Monographic Rearrangement of
Lophodermium” and “New Species and
Taxonomic Changes in the Hypoderma- —
taceae” (Tehon 1935, 1939d). He de-
scribed diseases affecting economic crops,
including those of fruits, vegetables, grain
and forage crops, and diseases of ornamen-
me Wien ea
December, 1958
tal plants, especially trees (Tehon 1925,
1939}, 1939c, 1943; Tehon & Stout
1928; Tehon & Jacks 1933; Tehon &
Boewe 1939; Tehon & Harris 1941). He
was especially interested in developing
methods and principles for interpreting
the phenology of crop pests (Tehon 1928).
Tehon’s botanical interests are indi-
cated by such publications as The Native
and Naturalized Trees of Illinois (with
Robert B. Miller), Rout the Weeds,
Pleasure With Plants, Fieldbook of Na-
tive Illinois Shrubs, The Drug Plants of
Illinois, and (with collaborators) Illinois
Plants Poisonous to Livestock (Miller &
Tehon 1929; Tehon 1937a, 1939a, 1942,
1951a; Tehon, Morrill, & Graham 1946).
He was a linguist and translated Gio-
vanni ‘Targioni ‘Tozzetti’s Alimurgia,
part V, 1767, an Italian article of 156
pages on diseases of wheat and other
cereals; the translation was published in
English as Phytopathological Classics No.
9 (Tehon 1952a).
RECENT ACTIVITIES
The early work in the Section of Bot-
any consisted not only of a survey of the
plant diseases in the state but the de-
velopment and co-ordination of research
in botany, with special emphasis on plant
diseases and the establishment of a her-
barium, which included a plant disease
collection and a native plant collection.
In an annual report Forbes (1923:386)
described the work of the botanical sec-
tion as follows:
Beginning in July, 1921, active work has
been done throughout the State on the fungus
parasites of the crop plants, many of which
are highly destructive and difficult to control.
It was the principal first object of this in-
quiry to make accessible existing knowledge
of the plant diseases of the State and of their
distribution in Illinois and their destructive-
ness, and to ascertain whether known meth-
ods of protection against them are generally
used, this to be followed by measures intended
to make crop growers acquainted with the
most important preventable diseases and the
losses due to them and with established
means for their prevention and control.
To aid in the work of the Section of
Botany the co-operation of 135 unpaid
field observers was obtained to watch for
plant diseases and to report any unusual
outbreaks of diseases occurring at any
CarTER: APPLIED BOTANY AND PLANT PATHOLOGY 149
time. The information obtained included
the crops attacked by each disease, the
stage of growth of the crop when at-
tacked, the damage caused, the first date
of appearance of disease, the amount of
damage to the crop, the control measures
used, and the prevalence and destructive-
ness of each disease.
As the work of the Section of Botany
continued to expand, greater emphasis
was placed on the application of research
information for the control of plant dis-
eases, and in 1935 the name of the section
was changed to Section of Applied Bot-
any and Plant Pathology. At this time
the activities of the section were divided
into four main groups, namely, (1)
Plant Disease Survey, (2) Botanical Sur-
vey, (3) Shade and Forest Tree Pathol-
ogy, and (4) Floricultural Pathology.
The first full-time staff member to con-
duct research on floricultural pathology
was not appointed until 1939.
Plant Disease Survey
The plant disease survey, started by
Tehon in 1921, included a survey of the
diseases of all crop plants of Illinois,
with special emphasis on field crops and
fruit crops. Among the persons who have
assisted in the plant disease survey since
its beginning are Charles O. Peake,
Charles L. Porter, O. A. Plunkett, Harry
W. Anderson, Paul A. Young, Gilbert L.
Stout, and G. H. Boewe. Constantine J.
Alexopoulos and Leo Campbell collected
numerous plants around peach orchards
in southern Illinois counties as part of a
study of possible hosts of the peach yel-
lows virus.
Field Crop Diseases. — After the
establishment of the Section of Botany in
July of 1921, flag smut of wheat was
the first major disease studied. This dis-
ease, discovered in Illinois in 1919, was
causing serious losses of wheat in the
East St. Louis area. The limits of the
disease in the state were determined, and
effective control measures, including a
quarantine, were enforced. By following
rigid quarantine regulations, which re-
quired burning all straw and treating all
grain sold for seed, and by introducing
varieties of wheat resistant to the disease,
it was possible to eliminate flag smut.
The effectiveness of this control program
150 Intinois NaArurAL Hisrory Survey BULLETIN
prevented the disease from spreading over
the whole soft wheat area.
Other activities of the Section during
the 1920's included warning cotton grow-
ers in southern Illinois of the diseases to
be encountered, discovering and destroy-
ing the only known instance of alfalfa
infestation by the stem nematode, and
collecting data on the prevalence and de-
structiveness of stinking smut of wheat.
By 1923 it had been determined that
165 diseases affecting 44 different crops
were present in the state. In that year
the estimated reduction in yield of Illinois
wheat caused by five diseases (leaf rust,
stem rust, stinking smut, loose smut, and
scab) was 7,712,800 bushels, valued at
$11,837,000.
In most years of the past decade the
estimated annual losses from diseases of
iy
ie ee
Vol. 27, Art. 2
Illinois wheat have been 5,500,000 to
7,150,000 bushels. The greatest loss in
a single year, 7,150,000 bushels, valued
at $15,158,000, occurred in 1950. In
1953, a year of minimum loss, the esti-
mated reduction in yield was only 368,-
800 bushels, valued at $586,400.
The estimated annual losses resulting
from diseases of corn usually are greater
than the losses resulting from diseases of
wheat. In the past decade the lowest esti-
mated reduction in corn yield, 54,250,000
bushels, valued at $82,450,000, occurred
in 1952 and the highest estimated reduc-
tion in yield, 168,100,000 bushels, valued
at $198,358,000, occurred in 1949. The
average annual estimated reduction in
yield of corn in Illinois during the past
decade was 90,626,100 bushels, valued at
$112,139,072.
_ Homemade mixer used about 25 years ago by plant pathologists of the Illinois Natural
History Survey to demonstrate effectiveness of chemical treatments in control of seed-borne dis-
eases of small grains.
December, 1958 CARTER:
The plant disease survey not only in-
dicates the annual losses caused by plant
diseases but reveals diseases new in the
state and the sudden and _ widespread
damage caused by any disease that has
caused only minor damage in preceding
years. Downy mildew of alfalfa appeared
generally in the state and was abundant
in the extreme north in 1924. This disease
had not been seen in Illinois previous to
that year. A new leaf spot of cowpea was
discovered in Clinton County in 1927. In
an article by Stout (1930), 16 new fungi
found on corn in Illinois were described.
Downy mildew of soybean, first reported
in Illinois in 1929, caused considerable
damage in 1935, when it was found in
12 counties. Brown stem rot of soybean,
first recognized in the state in 1944, sud-
denly became widespread and destructive
in 1948. This outbreak of the disease fol-
lowed a fortnight of low temperatures,
which ended on August 10. Septoria leaf
spot of broom corn was discovered in IIli-
nois in 1949 and was very destructive in
several fields west of Galton in Douglas
County.
Diseases recorded for the first time in
Illinois in recent years include ergot on
timothy, bacterial blister spot on apple,
charcoal rot on pepper, and downy mil-
dew on wheat in 1952; basal glume rot
on barley, anthracnose on sweet clover,
and rosette on cherry in 1954; Ascochyta
leaf spot on rhubarb and bacterial leaf spot
on mulberry in 1955; powdery mildew on
apple, ergot on oats, Helminthosporium
leaf spot on red top, and Gloeosporium
leaf spot on currant in 1956; and Phy-
tophthora root rot on alfalfa, Phytoph-
thora stem rot on lily, Cercospora leaf
spot on Deutzia, Abelia, ornamental
gooseberry, and wafer ash, downy mil-
dew on cucumber, squash, and water-
melon, rust on apricot, anthracnose on
iris, powdery mildew on pecan and frag-
rant sumac, Badhamia slime mold on
timothy, Herptobasidium scorch on bush
honeysuckle, and Phyllachora tar spot on
lespedeza in 1957.
In the plant disease survey, not only
are the various kinds of crops examined
but many plants in many fields of the
same crop are examined each summer.
For instance, in 1949, data on prevalence
and severity of wheat diseases were ob-
AppLiep BorANy AND PLANT PATHOLOGY 151
tained by examination of plants in 42
wheat fields that totaled 1,033 acres and
that were located in 38 widely scattered
counties of the state.
Another phase of the plant disease sur-
vey is that of forecasting the anticipated
occurrence and seriousness of plant dis-
eases. This forecasting has been notably
effective for Stewart’s disease of corn.
The bacterium that causes Stewart’s dis-
ease overwinters chiefly in the body of the
adult corn flea beetle (Chaetocnema puli-
caria). The mortality rate of the flea bee-
tle is affected by weather conditions dur-
ing hibernation.
Although forecasting the early season
or wilt stage of Stewart’s disease had pre-
viously been worked out by others, fore-
casting the late season or the leaf blight
stage was worked out by G. H. Boewe.
Making use of data accumulated in the
5-year period 1944-1948, Boewe found
that a winter temperature index rather
accurately forecast the late season develop-
ment of Stewart’s disease. The index for
any growing season was based on the sum
of the mean temperatures of the previous
winter months of December, January,
and February. While early season epi-
demics do not develop unless the index is
90 or above, light to moderate late sea-
son epidemics develop when the indexes
are between 80 and 85, and moderate to
heavy late season epidemics when the in-
dexes are above 85. No disease or only a
trace of disease develops when the in-
dexes are below 80. Forecasting of the
severity of disease each year has been
quite accurate.
The appearance and spread of new dis-
eases on crops in Illinois often are re-
corded first as a result of the annual sur-
vey made for plant diseases. Aid to farm-
ers in combating these diseases is made
through warnings and through publica-
tions such as Diseases of Small Grain
Crops in Illinois (Boewe 1939).
Fruit Diseases.—Of the many dis-
eases that affected fruit trees in the state
each year during the early years of the
plant disease survey, the most common
and destructive were scab, shothole,
brown rot, and leaf curl of peach; fire-
blight, frogeye, and blotch of apple; fire-
blight, leaf blight, and leaf spot of pear;
and shothole and leaf spot of cherry.
152 I-tinois NarurAL History SurRvEY BULLETIN
In early August of 1927 Professor
M. J. Dorsey of the University of Illinois
found, in a large orchard near Centralia,
the first authentic case of peach yellows
in Illinois. By 1929 the disease had
spread to 37 trees scattered in 11 orchards
located in Jefferson, Marion, Pike, and
Pulaski counties. In recent years peach
yellows has not been observed in Illinois.
Diseases which are destructive to the
peach crop and which have appeared an-
nually in recent years are scab, brown rot,
shothole, and peach leaf curl.
During the early years of the plant dis-
ease survey, nailhead canker was a serious
disease of apple trees. However, this dis-
ease disappeared from the orchards of the
state when growers eliminated those va-
rieties susceptible to the disease. ‘The
major destructive diseases of apples which
have continued to appear annually are
scab, fireblight, frogeye, and blotch. Mil-
dew has increased in destructiveness in
recent years because the sulfur fungicides
which controlled the disease in the early
years have been replaced by new types of
fungicides; these new materials more ef-
fectively control the other diseases of
apples. Cedar apple rust, which was prev-
alent and destructive for many years, is
controlled satisfactorily at present by some
of the recently developed fungicides, fer-
bam plus sulfur on the deciduous hosts,
Elgetol and acti-dione on the evergreen
hosts.
Many pear orchards in the state have
been severely damaged or destroyed by
fireblight. At present there is hope that
this disease can be effectively controlled
by some of the new antibiotic sprays.
Other diseases destructive annually to
pear trees are leaf blight and leaf spot.
The disease most destructive to cherry
trees in the state is shothole. Yellowing,
necrosis, and premature leaf drop, caused
by this disease, gradually reduce the vigor
of affected trees and, eventually, the qual-
ity and quantity of cherries produced.
Diseases that may appear annually on
other fruit crops are bacterial spot and
black knot of plum; black rot, downy
mildew, and powdery mildew of grape;
crown gall and rust of blackberry; an-
gular leaf spot of currant; leaf spot, leaf
scorch, and yellows of strawberry; an-
thracnose of raspberry, currant, and goose-
Vol. 27, Art. 2
berry; and Septoria leaf spot of black-
berry and raspberry. Although many of
these diseases are not destructive each
year, they cause serious losses in some
years.
Vegetable Diseases.—Although
vegetable crops are affected by many dis-
eases, only a few of the diseases cause
serious losses annually. The most com-
mon and destructive diseases in Illinois
are bacterial blight, halo blight, and
mosaic of bean; yellows of cabbage;
Ascochyta leaf spot, Fusarium wilt, and
powdery mildew of pea; Fusarium wilt,
mosaic, and bacterial leaf spot of pepper;
early blight, Fusarium wilt, black leg,
and scab of potato; and early blight,
Fusarium wilt, and Verticillium wilt of
tomato.
Botanical Collections
The first of the present botanical col-
lections of the Natural History Survey
was started in a small way in 1921. At
that time the collection of plant disease
fungi of the Natural History Survey was
separated from the collection of the Uni-
versity of Illinois. The vascular plants
collected with State Laboratory funds
and with Natural History Survey funds
previous to 1921 were left in the her-
barium of the University of Illinois.
Plant Disease Collection.—The
earliest reported specimens in the plant
disease collection of the Natural History
Survey are several hundred specimens col-
lected, 1918-1921, by H. W. Anderson
of the University of ‘Illinois. Collection,
identification, and preservation of such
specimens were expanded rapidly during
the four summers of 1921 through 1924,
when special emphasis was placed on ob-
taining information on the plant disease
situation of the state. To conduct this
plant disease survey, one to four men
were employed full-time each summer to
collect specimens of diseased plants in
each county of the state. This activity
resulted in adding over 18,000 plant dis-
ease specimens to the collection. Among
these specimens were five plant diseases
new to the state and 18 species of plant
parasites new to science.
In 1924 this collection contained type
specimens which represented three genera
and 73 species of plant-inhabiting fungi
December, 1958
first known for their occurrence in IIli-
nois. Although some specimens have been
added to the plant disease survey collec-
tion by all botany staff members since
1924, most of the specimens have been
added by Boewe, the plant pathologist
now responsible for the plant disease sur-
vey. Specimens of special interest sent to
the laboratory for diagnosis of disease are
added to the collection.
Gilbert L. Stout was the first plant
pathologist to devote full time to plant
disease survey work. He was succeeded
by Boewe in 1930. In this work diseased
plant material is carefully examined to
determine the specific disease involved.
Many specimens are collected not only as
characteristic examples of the disease but
for further study in the laboratory to
determine the organism causing the dis-
ease. Specimens of diseases new to the
United States, Illinois, or a county of the
state are preserved in the plant disease
collection.
As of April, 1958, the plant disease
collection contained 32,624 specimens. Al-
though this collection contains mostly
fungi that cause plant diseases, it also
contains specimens affected by disease-
causing bacteria, viruses, and noninfectious
agents. Information on new diseases has
been published in Mycologia, Phytopa-
thology, and the Plant Disease Reporter.
Vascular Plant Collection.—The
collection of vascular plants in Illinois by
Natural History Survey staff members
was begun in 1927 with the establish-
ment of a project on the accumulation of
plants of the state. By 1931 three addi-
tional projects had been added: mainte-
nance of a herbarium containing repre-
sentative plants of Illinois, maintenance
of a bibliography of Illinois plant records,
and maintenance of a card record of the
occurrence of plants in [llinois.
The first systematic collection of IIli-
nois vascular plants for the Natural His-
tory Survey was made by James Schopf,
who collected 1,676 specimens during the
summer of 1931. In September of 1931
Dr. Herman S. Pepoon joined the Survey
staff. Pepoon, with the assistance of E. G.
Barrett, collected 1,300 specimens. After
Pepoon left the Survey in 1933 the ac-
cumulation of Illinois plants was added
to the duties of the plant pathologists.
Carrer: APPLIED BoraANy AND PLANT PATHOLOGY 153
Much of the collecting was done by
Boewe in conjunction with his work on
the plant disease survey. In October of
1946 R. A. Evers joined the staff and
was assigned the botanical survey work.
His work is devoted almost exclusively
to a study of the flora and vegetation of
the state. Since 1946 he has collected
plant specimens annually in each of the
102 counties of the state.
Previous to 1947 the number of speci-
mens in the vascular plant collection was
increased by gifts of specimens from R. A.
Dobbs of Geneseo, R. A. Evers then of
Quincy, and G. D. Fuller of the Illinois
State Museum. Also, the herbarium of
Charles Robertson of Carlinville was ac-
quired. Since 1947, plant specimens, as
gifts or exchanges, have been received
from Franklin Buser (graduate student),
James Long of Amboy, Dr. V. H. Chase
of Peoria, Dr. Sidney Glassman of the
University of Illinois staff at Navy Pier,
Chicago, Dr. John Voigt of Southern
Illinois University, Dr. John Thieret of
the Chicago Museum of Natural History,
and others.
Thirteen species of plants have been
added to the known flora of Illinois by
Natural History Survey staff members
since 1947. They are Daucus pusillus,
Medicago arabica, Setaria faberti, Spec-
ularia biflora, Rudbeckia missouriensis,
Heliotropium tenellum, Eriochloa villosa,
Dicliptera brachiata, Cyperus lancas-
triensis, Haplopappus ciliatus, Verbascum
virgatum, Helianthus angustifolius, and
Jussiaea leptocarpa.
Publications resulting from the collec-
tion of vascular plants of Illinois include
a 339-page bulletin on native and nat-
uralized trees of the state (Miller &
Tehon 1929), two fieldbooks, one on
wild flowers (Anon. 1936) and one on
native shrubs (Tehon 1942), and articles
on genera and species of Illinois plants,
including several new to the state (Evers
1949, 1950, 1951, 1956; Evers & Thieret
1957).
Identification and preservation of vas-
cular plants in the Natural History Sur-
vey herbarium were under way to a
limited extent by 1927. In succeeding
years students have been employed to
mount specimens for the herbarium. In
1936 Richard A. Schneider was em-
154 Intinois NAtrurAL History SurvEY BULLETIN
ployed to identify the accumulated col-
lection of plant specimens. Although col-
lection, identification, and preservation of
vascular plant specimens were curtailed
during World War II, the herbarium
contained 13,749 specimens in May of
1943 and 17,339 specimens in October
of 1946. The abundant collection of plant
material in succeeding years has in-
creased the number of vascular plant
specimens in the herbarium to 70,600,
and approximately 8,000 additional speci-
mens are on hand to be added to the
herbarium. Under present conditions
three student assistants are employed to
prepare the plant material for placing in
the herbarium. A card index is main-
tained of all plant specimens.
The bibliography of Illinois plants,
started previous to 1931, is not up-to-date
because of lack of funds and lack of as-
sistants to examine the literature.
In co-operation with L. E. Yeager, R.
E. Yeatter, A. S. Hawkins, and D. H.
Thompson, fellow staff members doing
wildlife or fisheries research, botanists
made a census of waterfowl food plants
of the Chautauqua Drainage District, car-
ried on a survey of Illinois plants useful
to wildlife as food or cover, and con-
ducted experiments on propagation of
plants useful to wildlife as food or cover.
A collection of 848 samples of seeds was
developed for identification of seeds in-
gested by waterfowl.
Activities pertaining to the botany of
Illinois include preparation of manu-
scripts designed for publications, mainly
of an educational or popular type. These
publications are on such subjects as
noxious weeds, directions for the study
and identification of plants, drug plants
(Tehon 1937a, 1939a, 1951a), plants poi-
sonous to livestock (Tehon, Morrill, &
Graham 1946), and vegetation of hill
prairies in the state (Evers 1955).
The publication on the vegetation of
hill prairies is a report on an extensive
ecological study of 61 prairies on the
brow slopes of bluffs of the Mississippi
River from East Dubuque to southern
Illinois, the Illinois River from the big
bend near Hennepin to Grafton, and the
Rock and Sangamon rivers. This type of
publication by the Natural History Sur-
vey is a continuation of those published
Vol. 27, Art. 2
earlier by the State Laboratory of Nat-
ural History.
Shade and Forest Tree Pathology
The earliest reported conspicuous dying
of trees in Illinois was among the elms
in Normal-Bloomington and Champaign
in the period 1883-1886 (Forbes 1912a).
The next reported conspicuous dying
among elms occurred from 1907 through
1911, when many trees succumbed in
- southern Illinois. During this period con-
spicuous losses of elms were reported in
Cairo, Carbondale, Centralia, Clayton,
Du Quoin, Edwardsville, Fairfield, Ga-
latia, McLeansboro, Mount Vernon,
Quincy, Robinson, Sumner, and Van-
dalia. These 14 towns are located in 13
counties of western and southern Illinois.
Although the cause of the dying of elms
during these two periods was not de-
termined, it was suggested that some dis-
ease might be involved. Dying of feeder
roots, wilting of foliage, and dying of
terminal twigs was followed by death of
the trees. Many of the affected elms in
southern and western I[]linois were heavily
infested with the elm borer, Saperda tri-
dentata, and the red elm bark weevil,
Magdalis armicollis, called by Forbes the
reddish elm snout-beetle.
Elm Diseases. — A few years after
the establishment of the Section of Bot-
any in 1921, reports and inquiries were
received about a widespread wilting of
elms growing in commercial nurseries
and in decorative plantings, most of them
in northern Illinois. Some special exam-
inations made of these trees by Dr.
Christine Buisman of Holland, an expert
on elm diseases, revealed that the malady
was not Dutch elm disease. Research on
the cause and control of this wilting was
started in 1930. Until May, 1934, the
work was carried on by graduate students
—H. A. Harris, Leo Campbell, J. A.
Trumbower, and A. S. Peirce. In May
of 1934 J. C. Carter joined the staff as
a full-time plant pathologist to study dis-
eases of trees. Although intensive study
of the elm wilt problem was continued
for several years, other elm diseases and
diseases of other species of trees were
studied as they became evident. From 1934
to 1950 research on tree diseases was
carried on by Carter. With the expan-
December, 1958
sion of the tree disease research program
in 1950, additional plant pathologists
were added to the staff. The recent re-
search program has been carried on by four
plant pathologists, Richard J. Campana,
Walter Hartstirn, Eugene B. Himelick,
and Dan Neely.
In the studies on the cause and control
of the wilting of elms, it was found that
several fungi were involved. Although
the first report on this work (Harris
1932) indicated that several fungi were
capable of causing the wilting, later
studies showed that most wilting was
caused by the Dothiorella wilt fungus
and it was most serious in plantings of
trees that were weakened by overcrowd-
ing and by repeated annual defoliations
from heavy infestations of the spring
cankerworm. Spraying with copper and
sulfur fungicides was not effective in
noticeably reducing or preventing wilting.
This spraying included dormant and foliar
applications, in some years as many as one
dormant and seven foliar sprays. Al-
though research failed to find a control
for this type of wilting of elms, it showed
that applications of either sulfur or cop-
per fungicide in June and early July gave
excellent control of the black leaf spot
disease (Trumbower 1934). Control of
this disease in commercial nursery plant-
ings of elms increased the annual growth;
sprayed trees made as much growth in
4 years as unsprayed trees made in 5
years (Carter 1939).
A conspicuous and widespread dying of
elms which became evident in Danville
and Peoria in the late 1930’s appeared in
other areas in succeeding years. It now is
widespread and destructive throughout
the southern two-thirds of the state.
North of Peoria, Bloomington, Cham-
paign, Urbana, and Danville, it occurs
in only a few isolated places. The north-
ernmost isolated infection is in Rockford.
This disease, called phloem necrosis and
described as a virus disease in 1942
(Swingle 1942), has killed thousands of
elms in Illinois and is one of the two
major diseases that continues to kill thou-
sands of elms annually. In Champaign
and Urbana phloem necrosis killed 2,460
trees in a period of 14 years; this number
represents over 16 per cent of the total
elm population in the two cities. Mount
CarRTER: APPLIED BoTANY AND PLANT PATHOLOGY 155
Pulaski, with an elm population of ap-
proximately 600 trees in 1940, had all
but 19 elms killed by the disease by Sep-
tember of 1948.
During the late 1930’s and early
1940’s, in investigations of the wilting
and dying of elms, several fungi capable
of producing cankers were studied. Can-
ker diseases usually were confined to a
few trees in a planting of elms but were
found in plantings in widely scattered
locations in the state. The cankers caused
by species of Cytosporina, Phoma, and
Coniothyrium were prevalent only on
American elm. The canker caused by
Tubercularia ulmi affected the Asiatic
species of elm, Ulmus pumila and U.
parvifolia.
A serious and widespread wilting of
elms in Hinsdale was brought to the at-
tention of the Natural History Survey by
Village Forester W. E. Rose in 1939.
Intensive research on these elms resulted
in the discovery of a bacterial disease
called wetwood (Carter 1945). Wet-
wood is a chronic disease that affects most
elms but usually does not result in the
death of affected trees. Ulmus pumila is
especially susceptible to wetwood. Re-
search on this disease is described in a
42-page article under the title ““Wetwood
of Elms” (Carter 1945). The National
Arborist Association awarded a citation
to the author in “recognition of his ex-
cellent work’ reported in the article.
This work the Association “considered
the outstanding research during 1945 on
shade tree preservation.”
Dutch elm disease is the most destruc-
tive disease of elms in I]linois. Although
this disease was first discovered in the
United States at Cleveland and Cincin-
nati, Ohio, in 1930, it was not until 1950
that the first diseased elm was found in
Illinois. Only one tree affected with
Dutch elm disease was found in 1950, 11
were found in 1951, 24 in 1952, and over
500 in 1953. The numbers of counties in
which the disease has been found each
year were | in 1950, 4 in 1951, 9 in 1952,
15 in 1953, 55 in 1954, 74 in 1955, 86
in 1956, 94 in 1957, and 99 in 1958. The
rapid destruction of elms by the disease
is illustrated by the numbers of trees af-
fected each year in Champaign and Ur-
bana. Only one affected tree was found in
156 Intinois NATURAL
History SURVEY
Vol. 27, Art. 2
BULLETIN
Plant pathologists of the Illinois Natural History Survey culturing sample of American elm
suspected of being affected by the Dutch elm disease. Modern laboratory equipment enables the
plant pathologists to substantiate field diagnoses.
Urbana in 1951. The numbers of affected
trees in succeeding years in Champaign
and Urbana were 11 in 1952, 164 in
1953, 694 in 1954, 1,805 in 1955, 1,836
in 1956, and 2,116 in 1957. These 6,627
diseased elms represent over 44 per cent
of the elm population of Champaign and
Urbana when the disease was first found
there.
The Natural History Survey has had
one full-time plant pathologist conducting
research on elm diseases, including Dutch
elm disease, since July, 1951: Ralph W.
Ames in 1951 and 1952 and Richard J.
Campana in 1952 and later.
Oak Diseases.—Numerous inquiries
about diseases of oak during the 1930’s
led to a special investigation which culmi-
nated in the publishing of a preliminary
report (Carter 1941). Although a dozen
fungi were associated with the develop-
ment of canker and dieback diseases of
oak in the field, only one fungus, Dothio-
rella quercina, caused canker and die-
back under controlled experimental con-
ditions. The other organisms appeared to
produce canker and dieback only on trees
previously weakened by adverse growing
conditions.
Oak wilt, the most destructive and
widespread disease of oak trees in the
United States, was not found in Illinois
until 1942, when a few affected trees
were discovered in Ingersoll Park at
Rockford in Winnebago County. In fol-
lowing years the disease was found in
other counties; by 1958 it was killing
trees in 70 of the 102 counties of the state.
Extensive research on the disease was
started in 1950 with a grant of money
December, 1958
from the Forest Preserve District of
Cook County, Illinois. A graduate stu-
dent at the University of Illinois, E. A.
Curl, was employed on a half-time basis.
A second grant of money was received
from the Forest Preserve District in 1951.
Also in 1951, funds were obtained from
the National Oak Wilt Research Com-
mittee of Memphis, Tennessee, composed
of 10 hardwood industries, and from state
appropriations for research on the dis-
eases of trees. ‘These funds made it pos-
sible to add three plant pathologists in
1951 to conduct full-time research on the
oak wilt disease. The men employed were
Bert M. Zuckerman, George J. Stessel,
and Paul F. Hoffman. Additional funds
were obtained from the National Oak
Wilt Research Committee in 1952, 1953,
and 1954. Funds appropriated by the
state have continued to be a part of the
Natural History Survey’s regular budget.
These funds have made it possible to em-
ploy additional plant pathologists to do
research on oak wilt and other tree dis-
eases. In 1953 four men full-time and
two men half-time were conducting re-
search on oak wilt. At present, with only
state funds to support the research on oak
wilt, three full-time regular staff mem-
bers are continuing research on this dis-
ease. “The men who have helped to carry
on this program include E. A. Curl
(1950-1954), Bert M. Zuckerman,
George J. Stessel (1951-1952), Paul F.
Hoffman, Eugene B. Himelick (1952-
1954), Richard D. Schein (1952-1953),
Norman C. Schenck (1952-1953), Irving
R. Schneider, Harry Krueger (1954—
1955), Arthur W. Engelhard, James D.
Bilbruck (1955-1958), John M. Ferris,
R. Dan Neely, and Walter Hartstirn.
Persons whose names are followed by
dates were employed on research funds
granted to the Natural History Survey
by the Forest Preserve District of Cook
County, Illinois, or by the National Oak
Wilt Research Committee. The dates in-
dicate the periods of employment. Hime-
lick was employed on research funds
granted by the National Oak Wilt Re-
search Committee (1952-1954) before
he was employed by the Survey.
As a result of this extensive research
program on oak wilt, many papers were
published. The phases of research covered
CarTER: APPLIED BOTANY AND PLANT PATHOLOGY 157
in these papers include laboratory studies
on the morphology and physiology of the
fungus (Zuckerman & Curl 1953) and
isolation of the fungus from species of oak
on which it had not been previously re-
ported (Carter & Wysong 1951); green-
house studies on host range (Hoffman
1953) and experimental transmission of
the fungus by insects, mites, and squirrels
(Himelick, Curl, & Zuckerman 1954;
Himelick & Curl 1955, 1958); green-
house studies on infection by and spread
of C'*-labeled fungus in inoculated oaks
(Zuckerman & Hoffman 1953; Hoffman
& Zuckerman 1954) ; and field studies on
distribution and spread of oak wilt in
Illinois (Carter 1952), availability of oak
wilt inoculum in the state (Curl 1953,
1955a, 1955b; Himelick, Schein, & Curl
1953), characteristic growth of the fungus
under natural conditions (Curl, Stessel,
& Zuckerman 1952), discovery of the
perfect stage of the fungus in nature
(Curl, Stessel, & Zuckerman 1953;
Stessel & Zuckerman 1953), and effect of
the fungus on oak fence posts (Walters,
Zuckerman, & Meek 1955).
Other Diseases of Trees.—Al-
though oak wilt, elm phloem necrosis,
and Dutch elm disease are the most de-
structive tree diseases in the state, other
diseases of trees and of shrubs have been
sufficiently destructive to require the at-
tention of plant pathologists of the Nat-
ural History Survey. A wilt disease that
affects many species of trees in Illinois
is Verticillium wilt. It is known to affect
27 species of plants, including 7 varieties
of woody ornamentals representing 19
genera. Of the 27 species of woody hosts
of this disease, 12 were first reported in
Illinois: black locust, catalpa, Chinese,
English, and slippery elms, goldenrain
tree, linden, magnolia, multiflora rose,
tupelo, wayfaring tree, and yellow-wood.
Maple, elm, and catalpa are frequently
affected by this disease.
Canker diseases found in Illinois affect
different species of trees, including crab
apple, hawthorn, juniper, maple, moun-
tain ash, pine, poplar, redbud, spruce,
sycamore, and willow. Rust diseases are
widespread and destructive in some years.
They include cedar apple rust, cedar-
hawthorn rust, cedar-quince rust, pine
needle rust, and poplar leaf rust.
158 Inuinois NatuRAL History SurvEY BULLETIN
Foliage diseases which cause especial
damage during cool, moist springs affect
many species of trees. The most destruc-
tive foliage diseases are anthracnose of
ash, maple, oak, and sycamore; blotch of
buckeye and horsechestnut; and leaf spot
of elm, hawthorn, maple, oak, and walnut.
Some trees decline and die each year
because of unfavorable growing condi-
tions that include physiological disorders,
adverse weather conditions, and mechani-
cal injuries. These conditions, as well as
disease organisms, have received the at-
tention of Natural History Survey plant
pathologists.
Research on the control of foliage dis-
eases includes testing of numerous fungi-
cides each year. In some years as many
as 18 species of trees have been treated
with fungicides and as many as 12 differ-
ent fungicides have been tested on one or
more species. An example of an effective
control measure resulting from these tests
is the use of organic mercury fungicides
to control anthracnose of sycamore.
Chemotherapy.—One phase of Nat-
ural History Survey research on the con-
trol of tree diseases relates to the effec-
tiveness of various chemicals in prevent-
ing fungi from infecting trees or from
causing disease symptoms after they have
infected the trees. The early studies were
confined mainly to oak wilt; the present
studies include diseases of several species
of trees and especially oak wilt, Dutch
elm disease, and Verticillium wilt of elm,
maple, and other trees. Of the hundreds
of chemical compounds tested, a few
systemic fungicides and antibiotic ma-
terials appear to be effective in preventing
disease development. To obtain more in-
formation on what happens when these
materials are introduced into trees, plant
pathologists are studying the physiology
of trees as well as the physiology of the
fungi. The staff members who have car-
ried on this program are Paul F. Hoff-
man, Eugene B. Himelick, Irving R.
Schneider, John M. Ferris, and Walter
Hartstirn.
Floricultural Pathology
Little research by the Natural History
Survey was done in floricultural pathol-
ogy before 1939. In response to numerous
requests for help in dealing with disease
Vol. 27, Art. 2
problems in floricultural crops, a_ pro-
gram of research was initiated, and Don
B. Creager was appointed to the staff in —
September of 1939. This program, car-
ried on by Creager for 5 years and con-
tinued by J. L. Forsberg, included work —
on diseases of greenhouse crops and field- —
and garden-grown floricultural plants.
Much attention was given to bulbous
ornamental plants, which were being
propagated extensively in Illinois for —
shipment to other states.
The early work was concerned with
(1) obtaining as much information as
possible about diseases important to IIli- —
nois growers, (2) conducting research on
diseases for which vital information on
cause and control was lacking, and (3)
rendering every possible aid to growers
in the recognition and control of diseases —
in their crops. As the work progressed
more attention was given to developing
disease control measures that would be —
more effective than those that were being
used.
Crops which have received attention
during the course of this work are ama- |
ryllis, aster, azalea, begonia, calla, carna- :
tion, chrysanthemum, gardenia, geranium, —
gerbera, gladiolus, hollyhock, hydrangea, —
iris, ivy, lily, orchid, peony, peperomia,
periwinkle, petunia, poinsettia, rose, Afri- —
can violet, snapdragon, stevia, stock, —
sweet pea, tuberose, tulip, violet, and
zinnia. Of these crops, gladiolus, rose,
and carnation are grown in greatest —
quantity, and, since all three crops are
subject to a number of destructive dis-
eases, more work has been done on them
than on the other crops.
Because of the serious losses due to
diseases of gladiolus in the large com-
mercial gladiolus growing area in Kan-
kakee County, much research work has —
been directed toward developing effective —
control measures for these diseases. Prior
to 1940, gladiolus corms generally were —
not treated for disease control, but in re-
cent years nearly all commercial gladiolus
planting stocks in all parts of the United
States have been treated with a fungicide
before being planted. This practice has —
developed largely as a result of the suc- —
cess of experimental treatments by Illi-
nois Natural History Survey pathologists.
If these or other equally effective treat-
December, 1958
ments had not been worked out, the
gladiolus industry in Illinois would have
succumbed.
Among other noteworthy accomplish-
ments achieved by Natural History Sur-
vey pathologists in the field of floricul-
tural pathology are the following: control
of peony measles with an Elgetol ground
spray (Creager 1941c, 1943a); control
of black mold of rose grafts by chemical
treatments (Creager 1941); control of
balla rots by chemical treatments
(Creager 1943+) ; establishment of viruses
as the causes of peperomia_ ringspot
(Creager 1941a), carnation mosaic and
streak (Creager 1943c, 1944, Forsberg
1947), and coleus mosaic (Creager
1945) ; clarification of the Fusarium dis-
ease complex in gladiolus (Forsberg
1955a); discovery of the vascular phase
of the Curvularia disease of gladiolus
(Forsberg 1957); discovery of scab on
violets in Illinois (Forsberg & Boewe
1945); control of Thielavia root rot of
sweet peas (Creager 1942); control of
bacterial scab of gladiolus by use of soil
insecticides (Forsberg 1955d).
The value of an insecticide in the con-
trol of bacterial scab of gladiolus became
apparent in 1953 when gladiolus corms
were treated with a seed protectant which
contained an insecticide in addition to a
fungicide. This treatment resulted in the
production of corms free of bacterial
scab and free of injury caused by white
grubs. Results of this treatment supported
observations that white grubs are instru-
mental in spreading bacterial scab. Suc-
ceeding tests showed that 25 per cent al-
drin granules applied to the soil at the
rate of + or 8 grams per 10 feet of row
prevented white grub injury and _bac-
terial scab.
Identification and Extension
During each growing season the Sec-
tion of Applied Botany and Plant Pathol-
ogy receives for examination and diagnosis
several thousand samples of trees, shrubs,
and other plants suspected by [Illinois
residents of being diseased. Diagnosis
results and treatment recommendations
are sent as soon as possible to the persons
sending the samples.
Most of the samples received are from
elms suspected of being affected with
CARTER: APPLIED BOTANY AND PLANT PATHOLOGY
159
Dutch elm disease. To handle the labora-
tory diagnoses requires the full-time help
during the summer months of four ad-
ditional persons: one mycologist, two lab-
oratory technicians, and one stenographer.
It is anticipated that the demand _ oc-
casioned by Dutch elm disease for service
from Natural History Survey personnel
will continue indefinitely.
To supply the demand from hundreds
of communities and individuals through-
out the state for information on identifi-
cation, control, and other aspects of
Dutch elm disease has occupied a major
portion of the time of one plant pathol-
ogist. Educational material on Dutch elm
disease has been prepared for distribution ;
this has included mimeographed leaflets on
control and other phases of the disease, a
series of news releases, kodachrome trans-
parencies, black and white photographs,
specimens, exhibits, maps, tables, and
graphs. Technical advice and information
were furnished the Illinois State Cham-
ber of Commerce for two state-wide con-
ferences on Dutch elm disease, one in
1955 and one in 1956. These conferences
provided specific and detailed information
on the nature and control of the disease.
Outstanding authorities on Dutch elm
disease in the United States were on the
programs. Additional activities have in-
cluded aid in field identification of the
disease, aid in local surveys, training and
instruction in collecting specimens, set-
ting up laboratories for final diagnosis
of the disease, and making laboratory
diagnosis of each of several thousand
specimens received each year.
Each year, activities of an educational
or extension nature by staff members of
the Section of Applied Botany and Plant
Pathology include talks on plants and
vegetation of Illinois, and on diseases of
trees, shrubs, and floricultural crops. Ex-
aminations are made of numerous plant-
ings of ornamental and economic crops
in various parts of the state. Numerous
pasture lands are examined in co-opera-
tion with members of the University of
Illinois College of Veterinary Medicine
for plants poisonous to livestock. Many
plants examined in the field or received
throuzh the mail are identified for farm-
ers, homeowners, and other interested
persons.
160 Ittinois NatrurAL History SurvEY BULLETIN
PAST AND PRESENT
Early botanical research in Illinois was
concerned mainly with field surveys of
plants native to the state and with the
distribution of these plants in the state.
Although botanical research in the state
is still concerned with native plants, it is
concerned also with the cause and control
of diseases affecting ornamental plants—
trees, shrubs, and floricultural crops—
and losses caused by diseases of economic
crops, including cereal, fruit, forage, pas-
ture, and vegetable crops.
Much of the early work with plants
was done by amateur botanists who had
very little formal training in botany.
Some of these men were physicians who
were interested in plants that had medic-
inal values. These early botanists were
individuals, engaged in various profes-
sions or businesses, who were keenly inter-
ested in nature, especially in the plant life
around them. They usually studied plants
in local areas, as their modes of travel
were by foot, by horseback, or by car-
riage. Their equipment and_ reference
works were meager. Their efforts were
directed mainly toward the collection and
identification of plants.
Many of these early botanists were
members of the Natural History Society.
Some of them became professional bot-
anists and were employed by the State
Laboratory of Natural History.
Inheritors of some of the traditions of
these early botanists are the present mem-
bers of the Section of Applied Botany and
Plant Pathology of the Natural History
Survey. Unlike the early botanists, these
men have received specialized botanical
training in leading colleges and universi-
ties of the United States. Their fields of
specialization include botany, taxonomy,
plant pathology, plant physiology, mycol-
ogy, and biochemistry.
They are provided with specialized
equipment including high-powered com-
pound and phase microscopes, high-speed
centrifuges, pH meters, fluorescent lamps,
spectrophotometer, and Geiger counter,
and with excellent library facilities in-
cluding numerous books on_ specialized
subjects in botany and related fields.
They are able to study plants in all parts
of the state, as they can rapidly travel]
Vol. 27, Art. 2
great distances by automobile, train, air-
plane, or helicopter. They study the tax-
onomy of plants, as the early botanists
did, and in addition the pathology, physi-
ology, mycology, and biochemistry of
plants, including fungi, and _ especially
the fungi that cause diseases of plants.
UNSOLVED PROBLEMS
The partially solved problems receiv-
ing major attention of the Section of Ap-
plied Botany and Plant Pathology at
the present include the control of glad-
iolus corm rots, oak wilt, elm phloem ne-
crosis, and Dutch elm disease. Although
these diseases have been investigated for
several years, continued research is needed
to develop more effective treatments for
their control. Other unsolved problems
include the abnormal growth, wilt, de-
cline, or death of trees, floricultural
crops, and shrubs used for ornamental,
shade, or forest purposes. Some specific
unsolved problems are a virus disease
complex of gladiolus, a general decline of
ash, elm, and oak in localized areas of
the state; a rapid decline and death of
red pine in localized plantings in north-
ern Illinois; wilt, occasionally followed
by death, of ash, catalpa, fragrant sumac,
Japanese quince, and hard maple; a
needle blighting of white pine; diseases
of hackberry, Norway spruce, and white
pine, with symptoms suggesting virus dis-
eases; and wetwood of elm.
Although a research program on the
control of diseases of fruit, grain, and
vegetable crops is conducted by the Agri-
cultural Experiment Station at the Uni-
versity of Illinois, some of the unsolved
or partially solved problems are men-
tioned here. Because of the continued ap-
pearance of new physiologic races of rust
on small grains, it is essential to develop
new varieties of grains resistant to these
races. Also needed are varieties of small
grains resistant to scab and loose smut.
Another disease of small grains that needs
further study is the virus disease known
as yellow dwarf.
Corn is affected by stalkrots caused by
several fungi; varieties of corn are needed
that are resistant to the stalkrot caused by
each fungus. Other problems include
more effective control for bacterial spot
December, 1958
of pepper and for diseases caused by soil-
borne microorganisms including bacteria,
fungi, and nematodes.
If the future can be measured in terms
of experience in the past, new diseases
and other types of new plant disorders
will appear each year to require addi-
tional attention of the research personnel
of the Section of Applied Botany and
Plant Pathology.
FUTURE POSSIBILITIES
Future possibilities in the botanical
survey include further collections of na-
tive and naturalized vascular plants to
increase the knowledge of the habitats
and the range of these species in the state.
As plants migrate, slowly under natural
conditions but swiftly with the help of
man, it is necessary to be on the alert for
new additions to the state flora and to
give warning if any introductions are of
an obnoxious character. The final aim
of a floristic study is to produce a manual
of the flora of Illinois which will give
not only good descriptions of the species
but also a discussion of the variations of
the species within the state and a discus-
sion of their distribution in Illinois.
Collections of the nonvascular plants
—algae, fungi, and bryophytes—should
be expanded. Although a small collec-
tion of bryophytes—mosses and_liver-
worts—is housed in the herbarium, much
collecting remains to be done before the
present bryophyte flora and its distribu-
tion in the state can be known. A nu-
cleus of a phycological collection has been
made and should be increased. Only a few
of the nonpathogenic fungi are repre-
sented in the Natural History Survey col-
lections. Collections of slime molds,
lichens, and fleshy fungi—mushrooms and
bracket fungi—should be started, as these
plants are a part of the flora of Illinois
and thus a part of the natural resources
of the state.
Vegetational studies should be contin-
ued. Although many of the original prai-
rie types of Illinois have been destroyed
_ and only remnants remain, these remnants
should be described so that future citizens
of Illinois will have some botanical
knowledge of the prairie types. Hill prai-
rie studies should be continued to solve
CARTER: APPLIED BOTANY AND PLANT PATHOLOGY 161
some of the problems of succession in this
type of prairie and to learn how such
prairie recovers from heavy grazing. Ad-
ditional study should be made of the vege-
tation of the sand areas of the state. An
ecological study of the forests in Illinois
should be made. The ultimate aim of
these studies is to produce a manual of
the plant geography of Illinois.
Not only should the various vegetations
of Illinois be described; remnants of
them should be preserved. This is true
especially of the prairie types. As we do
not know what lies in the future for land
use in the locations of the present hill
prairies, now one of the least disturbed
prairie types in Illinois, several of these
beautiful grasslands should be set aside
as natural areas by the state or federal
government and should be so adminis-
tered that picnic parties, hunters, or oth-
ers cannot disturb them but that inter-
ested persons may view and study them.
Although only very small remnants of the
flatland and bottomland types of prairie
remain, several such remnants should be
set aside and allowed to expand so that
future generations may have a general
idea of the nature of these types of prairie
which gave the name “the prairie state”
to Illinois. Examples of sand prairies
should be preserved. Some of these prai-
ries which come under state control should
be left as prairies instead of being
converted into pine plantations. Aban-
doned railroad trackways in sand prairie
regions should be permitted to develop as
a type of the sand prairie. Other vegeta-
tions also should be preserved. The bogs
in northeastern Illinois, in Lake County,
are valuable from the botanist’s point of
view. The few remaining, sizable tam-
arack bogs could be easily set aside for the
study of bog plants and animals and of
succession in the bogs.
Future research on plant diseases will
continue the advancement of present re-
search, and new fields of research will
open up. Some of the types of research
that appear promising in the control of
plant diseases include the use of chemo-
therapeutants, antibiotics, and soil fungi-
cides. Further research is needed on in-
secticides and their indirect role in the
control of plant diseases. One instance
of this is illustrated in the control of bac-
162
terial scab of gladiolus by use of aldrin
to prevent white grub injury to the corms.
Chemical compounds obtained from min-
eral deposits in the state hold promise
for the control of some plant diseases
(Schenck & Carter 1954). Research on
these compounds through the co-operation
of the Geochemical and Coal sections of
the Illinois Geological Survey and the
Wright Air Development Center of the
United States Air Force has been fruitful
in the development of fluorine compounds _
with fungicidal properties against certain
disease-producing fungi. Research along
these lines resulted in publication of six
articles on the fungistatic capacities of
aromatic fluorine compounds in relation
to cloth-rotting fungi (Tehon 1951),
19526, 1954; Tehon & Wolcyrz 1952a,
1952b; Finger, Reed, & Tehon 1955).
Research on the physiology of plants
and on organisms that produce plant dis-
eases will aid materially in the develop-
ment of more effective controls for these
diseases. One objective of this research
is to develop a more realistic approach to
the control of diseases through obtaining
information on the movement of raw ma-
terials, elaborated foods, and chemical
I_ttrnois NATuRAL History Survey BULLETIN
Vol. 27, Art. 2
compounds introduced into woody plants.
The addition of a plant physiologist to
our staff would materially increase re-
search in this field.
In our study of several thousand speci-
mens of diseased ornamental plants each
year, many unknown fungi are obtained.
These fungi need to be identified and
those that are found affecting new hosts
or that have not been found previously in
the state should be added to our myco-
logical collection. To adequately handle
this work, to make monographic studies
of economically important fungi, and to
attack new mycological problems as they —
appear, a mycologist with special interest
in economic fungi would greatly facilitate
our research.
As we contemplate the future possibili-
ties for research by the Section of Ap-
plied Botany and Plant Pathology, it is
evident that there are unlimited oppor-
tunities not only to continue the research
now in progress but to expand into new
fields of research. This statement applies
to the botanical survey, the study of vege-
tation, the study of diseases of ornamental
plants, and the study of the various kinds
of fungi that occur in the state.
et aa
Mea AE ta es epee be
one al SA lt ith,
eee, ee
ee > ae
oe
wean Moar OP is
Aquatic Biology
me research in aquatic biology that
was so much a part of the endeavors
of the staff of the Illinois State Labora-
tory of Natural History and later the
Illinois Natural History Survey was in-
itiated by Stephen A. Forbes. From the
very beginning of his active period in
Illinois, Forbes showed great interest in
fishes and he began collecting specimens
for species records, distributional records,
and food habits studies. He wrote ar-
ticles on Illinois Crustacea and food of
Illinois fishes for the first volume of the
Bulletin of the Illinois State Laboratory
of Natural History (Forbes 1876, 1878a,
18804, 1880c, 18834, 1883c). In the pe-
riod 1876-1888 he collected 1,221 fish of
87 species, 63 genera, and 25 families;
these he used to study their diagnostic
characteristics, their distribution in the
state, and their food habits. Forbes’ inter-
est in aquatic biology was broad, and he
himself worked on or arranged for others
to work on crustaceans, leeches, proto-
zoans, rotifers, and aquatic insects, as well
as fishes native to I ]linois.
BEGINNING OF AQUATIC
ECOLOGY
Many of the early publications of the
Illinois State Laboratory of Natural His-
tory dealt with the taxonomy and distri-
bution of aquatic animals new to science,
or additions to the known distribution of
named animals. Forbes was familiar with
these subjects and also with the ecology
of aquatic organisms at least as early as
1887. In that year his ‘“The Lake as a
Microcosm” was first published in the
Bulletin of the Peoria Scientific Associa-
tion; later it was republished in volume
15 of the Bulletin of the Illinois State
Laboratory. In this short but epoch-
marking paper, Forbes (1925) described
a lake or pond as an environment in
which the animals and plants were
largely isolated from the surrounding ter-
restrial animals and plants ‘but were very
much interrelated and _ interdependent
GEORGE Wy BENNETTS
among themselves; each organism was
producing more new individuals than the
environment could support, so that many
of them served as food for other types of
animals, and competition was very keen.
Forbes had observed the biological phe-
nomena associated with fluctuating water
levels—with floods following excessive
precipitation and low waters following
droughts—and described them as follows:
Whenever the waters of the river remain for
a long time far beyond their banks, the breed-
ing grounds of fishes and other animals are
immensely extended, and their food supplies
increased to a corresponding degree (Forbes
1925:538).
As the waters retire, the lakes are again de-
fined; the teeming life which they contain is
restricted within daily narrower bounds, and
a fearful slaughter follows; the lower and
more defenceless animals are penned up more
and more closely with their predaceous en-
emies, and these thrive for a time to an
extraordinary degree (Forbes 1925:539).
Forbes recognized that periods of bio-
logical expansion and contraction were
normal and, without the introduction of
abnormal forces, would tend to hold
“each species within the limits of a uni-
form average number, year after year.”
Every organism had its enemies that
seemed to be balanced against its repro-
ductive potential and, although every
species had to “fight its way inch by inch
from the egg to maturity,” yet no species
Was exterminated.
Apparently the Illinois State Fish
Commissioners, assigned the duties of
protecting the fisheries resources of the
state during this period, either had not
read Forbes’ ““The Lake as a Microcosm”
or did not understand it, because their
main activity for the 20 years following
1890 was the rescuing of fishes from the
land-locked, drying backwaters of the
Illinois and Milississippi rivers and the
returning of these fishes to the open wa-
ters.
Perhaps the Commissioners should not
be condemned severely, because their be-
liefs and activities were in no way dif-
[ 163 J
164
ferent from those of similar bodies in
other states throughout the country. They
were in tune with the times. In the re-
port of the Commissioners to the Gov-
ernor of Illinois for the period October 1,
1890, to September 30, 1892 (Bartlett
1893:3), is to be found the following
statement:
The number of fish left to die in the shal-
low waters has been beyond computation,
and has seemed to be greater than ever
before, from the fact that the attention of
the people generally has been called to them
and the terrible waste ensuing... .
We have been severely criticised because
so many fish are allowed to perish, but when
the fact is considered that the Mississippi
river has a meandering frontage of 450 miles
in this State, with bottoms varying in width
from a few hundred yards to several miles,
and the Illinois and other rivers adding per-
haps as much more, it can readily be seen
that, if the work were carried on to a suc-
cessful completion, it would require hundreds
of men and thousands of dollars of ex-
pense; in other words, it would be simply
impracticable.
Fish rescue operations were done with
seines dragged through shallow waters by
crews of men. The fish were separated
from the mud and vegetation and carried
by boat to open water, or in tubs to tanks
on wagons when overland transportation
was necessary. The operations were car-
ried on in summer and early fall when
both the water and the air were very
warm. Today fisheries biologists are
well aware of the fact that, even if the
fish had been released “alive” in open
water, their chance of survival was very
low. Few fishes are able to survive even
a short exposure to a lukewarm, mud-
and-water suspension, such as is created
when a seine is dragged through shallow
backwaters in August. ‘This statement
applies particularly to the game and fine
fishes.
We now suspect that the phenomenon
of fluctuating water levels, which cre-
ated a fish rescue problem along the IIli-
nois and Mississippi rivers for the Illinois
State Fish Commissioners, may have been
highly favorable to the well-being of the
population of fishes, particularly large-
mouth bass, northern pike, walleyes,
crappies, and other pan fishes. A com-
bination of natural predation (largely
by fish-eating birds) and water level fluc-
tuations prevented excessive competition
Intinois NarurAL History SurvEY BULLETIN
among the coexisting species and allowed
for excellent survival of game fish. The
Vol. 27, Art. 29
report of the Fish Commissioners (Bart- —
lett 1893:4) for the 2-year period ending
September 30, 1892, contains the follow- —
ing statement:
In the Quincy Bay [of the Mississippi River],
this season, the number of black bass has been
unprecedented, and a fair estimate of the
number taken with hook and line would
place it in the hundreds of thousands. Most
of them were too small to use on the table,
yet were as voracious as larger ones and fell
an easy prey to the angler, whether he of
the rod and reel or the small boy with a
willow switch and a tow line, all caught
bass. One man, who called himself a sports-
man, boasted of having caught 800 of them
in one day with hook and line, all too small
to eat, but he carried them away and threw
them on the ash heap. From my office win-
dow I saw 225 taken by two little boys in
one day, all of them wasted.
The production of a dominant brood
of bass (undoubtedly largemouth) such
as this might be expected to follow a pe-
riod of very low water in the late sum-
mer and fall and a period of moderately
high water during the bass spawning sea-
son the following June.
The theory of the benefits of fluctuat-
ing water levels is further substantiated
by a published record of the catch of four
commercial fishing firms operating in the
Illinois River near Havana between July
1 and December 1 (5 months) in 1895
(Roe & Schmidt 1897). Their catch was
358,843 pounds, mostly of carp and buf-
falo, which made up 85.7 per cent of the
total. An unusual part of the catch was
the proportion of “bass” (undoubtedly
largemouth), 7,852 pounds, and walleye :
and “pike” (northern), each 200 pounds.
The last two species are seldom taken in
the Illinois River today. The catch of bass
(7,852 pounds) was larger than the catch
of crappies (7,405 pounds). Crappies are
easily caught in hoop and fyke nets or
seines; bass do not enter hoop and fyke
nets readily and when surrounded with a
seine they show considerable aptitude for
jumping over. Inasmuch as more pounds
of bass than of crappies were caught, prob-
ably many more pounds of bass were
available.
Today, with water levels of bottom-
land lakes in the Havana region much
more stabilized, it would be an impossi-
December, 1958
ble task to catch 7,000 pounds of bass
with commercial fishing gear. This im-
portant game species is very much less
abundant now than it was when the river
was free to spread over its wide flood
plain.
FIRST FIELD LABORATORY
Forbes was much interested in the Illi-
nois River and in 1894 he established a
biological station on its shores (Forbes
1895a:39) “for the continuous investiga-
tion of the aquatic life of the Illinois river
and its dependent waters, near Havana.”
That Forbes (1895a:46-7) had great
breadth of vision in biological research is
shown by his description of the objectives
of the laboratory:
The general objects of our Station are to
provide additional facilities and resources for
the natural history survey of the State, now
being carried on, under legislative authoriza-
tion, by the State Laboratory of Natural His-
tory; to contribute largely to a thoroughgoing
scientific knowledge of the whole system of
life existing in the waters of this State, with
a view to economic as well as educational
applications, and especially with reference
to the improvement of fish culture and to the
prevention of a progressive pollution of our
streams and lakes; to occupy a rich and
promising field of original biological investi-
gation hitherto largely overlooked or neglect-
ed, not only in America, but throughout the
world; and to increase the resources of the
zoological and botanical departments of the
University by providing means and facilities
for special lines of both graduate and under-
graduate work and study for those taking
major courses in these departments.
The Station differs from most of the small
number of similar stations thus far estab-
lished in this country from the fact that its
main object is investigation instead of in-
struction, the latter being a secondary, and
at present an incidental object only. It has
for its field the entire system of life in the
Illinois river and connected lakes and other
adjacent waters, and it is my intention to
extend the work as rapidly as possible to the
Mississippi river system, thus making a
beginning on a comprehensive and_ very
thoroughgoing work in the general field of
the aquatic life of the Mississippi Valley,
in all its relations, scientific and economic.
The special subject which I have fixed
upon as the point of direction towards which
all our studies shall tend is the effect on the
aquatic plant and animal life of a _ region
produced by the periodical overflow and
gradual recession of the waters of great
rivers, phenomena of which the Illinois and
Mississippi rivers afford excellent and strong-
ly marked examples.
BeNNeETY: AQuatic BIoLocy 165
Forbes (1895a:47) believed that the
natural sciences should be studied out of
doors and that colleges and universities
of his day were not doing well by their
students in botany and zoology when they
confined them to laboratory studies:
Not many years ago, biological instruction
in American colleges was mostly derived
from books. Of late, it has been largely ob-
tained from laboratories instead, but several
years’ experience of the output of the zodlogi-
cal college laboratory has convinced me that
the mere book-worm is hardly narrower and
more mechanical than the mere laboratory
grub. Both have suffered, and almost equally,
from a lack of opportunity to study nature
alive. One knows about as much as the other
of the real aspect of living nature and of the
ways in which living things limit and de-
termine each others’ activities and characters,
or in which all are determined by the in-
organic environment.
It is possible that Forbes’ feeling on
this point of training may have influenced
the University of Illinois to require field
courses at a_ biological station before
granting a graduate degree in zoology.
Havana was selected as the location for
the Illinois Biological Station because of
its several advantages: Forbes liked the
bluffs along the eastern shore of the IlIli-
nois River because at their bases they
furnished a clean, hard sand beach suit-
able to work from and ideal for camping.
Moreover, along these bluffs was an
abundance of pure, cold spring water.
The laboratory consisted of “three
well-placed rooms” in the town itself and
a “cabin boat” on the Illinois River.
The office and laboratory rooms were sup-
plied with running water and electric light,
and liberally provided with the usual equip-
ment of a biological laboratory, consisting of
compound and dissecting microscopes (Rei-
chert and Zeiss), microtomes, biological re-
agents to the number of one hundred bottles,
water and [paraffin] baths, laboratory glass-
ware, tanks for alcohol, a coal stove, a kero-
sene stove, laboratory tables for five assist-
ants, and a working library of about one
hundred and twenty volumes’ (Forbes
1895a:48).
The cabin boat was stationed on Quiver
Lake north of Havana, about 2.5 miles
from town. The boat contained a well-
furnished kitchen and sleeping quarters
for four men. Most of the rest of the
space was taken up by equipment, includ-
ing limnological apparatus, seines, collect-
ing nets, microscopes, and a small library.
166 I_tinois NATURAL History SuRVEY BULLETIN
The original staff of the station, in
1894, consisted of Frank Smith, who was
directly in charge and whose principal in-
terest was aquatic worms; Charles A.
Hart, entomologist and curator of col-
lections for the State Laboratory; Adolph
Hempel, who worked on protozoans and
rotifers; and Mrs. Dora Smith, who
served as microtechnician and was in
charge of the rooms in Havana. Miles
Newberry, who lived in Havana, had
charge of the cabin boat and acted as a
general field assistant. Others who were
present at some time during the first year
of operation were Ernest Forbes, for 6
weeks of general collecting, Professor
Thomas J. Burrill, a Mr. Clinton, a Mr.
Yeakel, and a Miss Ayers, all of the Uni-
versity of Illinois Botany Department,
who were collecting aquatic plants; a
Professor Palmer, who was making chem-
ical analyses of the water; Assistant Pro-
fessor Henry E. Summers of the Univer-
sity Physiology Department, who photo-
graphed the region; and the staff artist,
Miss Lydia M. Hart. Professor Forbes
exercised general supervision over the sta-
tion work, planning and following its op-
eration.
FISHES AND PLANKTON
Within a year or so aquatic investiga-
tions were stepped up through increased
use of the laboratory and cabin boat at
Havana. At the beginning of this cen-
tury Frank Smith (1901:567) stated in
Science that the ichthyological survey of
Illinois had received much attention dur-
ing the previous 2 years and that a com-
prehensive report was soon to be pub-
lished. He also stated that Dr. C. A.
Kofoid had been studying the plankton
of the Illinois River for the previous 5
years. This short statement in Science
announced the progress being made on
two of the important contemporary con-
tributions to aquatic biology, namely
Forbes & Richardson’s The Fishes of
Illinois (1908) and Kofoid’s studies on
the plankton of the Illinois River.
Shortly after, in an essay dealing with
“statistical ecology,” Forbes (1907a) pre-
sented a method for showing relation-
ships between individual species of fishes
and preferences of certain kinds of fishes
Vol. 27, Art. 2
with respect to features of the physical
environment. The validity of this method
depended upon the numbers of collections
that were available for study. Where
sufficiently large numbers of collections
could be mustered, Forbes compared ob-
served relationships with expected rela-
tionships and obtained a coefficient of as-
sociation by dividing the former by the
latter. A hypothetical example is given
below:
Given species 4 and species B inhabit-
ing waters in the same general land area:
In 1,000 collections, species 4 occurred
159 times and species B 85 times. Thus,
the probability that they would occur to-
gether in any single collection was
159/1,000 85/1,000 or 13,515 times
in a million or 13.5 times in 1,000, and
the probable number of these double oc-
currences in the 1,000 collections was
13.5/1,000 > 1,000/1 or 13.5 times:
However, in the 1,000 collections, spe-
cies 4 and species B were found together
in 40; thus, the coefficient of association
for species 4 and B was 40/13.5 or 2.96:
they were found together about three
times as often as was to be expected.
This same type of reasoning was ap-
plied to show relationships between indi-
vidual species and the physical environ-
ment: stream, lake, pond, marsh; size of
water area and water movement; bottom
of mud, sand, gravel, or rock. These co-
efficients of association are found fre-
quently in Forbes & Richardson’s The
Fishes of Illinois. Unfortunately about
half the collections referred to in this pub-
lication were made without notes on wa-
ter current and bottom materials, so that
this method of showing association could
be applied only to stream, lake, pond, or
marsh, or to sectional distribution in the
state. Thus, when Forbes & Richardson
(1908:195) stated that the frequency
ratios for a fish were ‘3.19 for the smaller
rivers, 2.06 for creeks, and .58 for the
largest streams,” they meant that these
fish exceeded expectancy in “smaller riv-
ers” and “creeks” by about 3 and 2 times,
respectively, and were considerably below
expectancy in “the largest streams.” A
coefficient of association of 1 indicated
correspondence with expectancy; a co-
efficient below 1 indicated a negative re-
lationship.
December, 1958
This method of showing ecological re-
lationships between species and ranges,
species and local habitats, or between spe-
cies themselves, allowed the use of num-
bers to show the degree of the relation-
ship or lack of it. Its shortcoming was
that it made no distinction between col-
lections containing one fish of a species
under consideration and those containing
several hundreds or thousands.
THE FISHES OF ILLINOIS
The first edition of The Fishes of Illi-
nois was published by the State of Illinois
in 1908; a second edition was published
in 1920. Collections and observations for
this work had been started in 1876 by
Forbes and had been expanded through
the help of many assistants working at
rather irregular intervals until 1903.
Field work on fishes became nearly con-
tinuous for a few years after establish-
ment of the Illinois Biological Station at
Havana in 1894. Special recognition was
given to Wallace Craig, who collected
during the winter and spring seasons of
1898 and 1899, to H. A. Surface, who
collected during 1899, and to Thomas
Large, who made extensive wagon trips,
the most important of them in 1899, to
collect fishes from streams in many parts
of the state. Recognition was given also
to unnamed high school teachers who col-
lected fishes under specific instructions.
Collections of fishes studied by Forbes
and Richardson were taken from many
sources: catches made by collecting par-
ties with seines of various size and mesh
(including minnow seines and_ bag
seines), trammel nets, set nets (both fyke
and hoop) ; catches made by commercial
fishermen; and selections from fishes on
display in fish markets. More than 200,-
000 specimens representing 150 species
were collected from more than 450 loca-
tions in the state.
The Fishes of Illinois was published in
two parts, one of which was an atlas.
The larger or first part contained a sec-
tion on “The Topography and Hydrog-
raphy of Illinois’ written by Professor
Charles W. Rolfe, at that time head of
the Geology Department of the Univer-
sity, a section entitled “On the General
and Interior Distribution of Illinois
BENNETT: AQUATIC BIoLoGy 167
Fishes,” a section on “The Fisheries of
Illinois,” and one on the individual spe-
cies of fishes found in the state. This last
section made up by far the largest num-
ber of pages and included keys for the
identification of fishes and a glossary of
technical terms. For each species of fish
were given the scientific name, common
name or names, synonomy of scientific
names (where such existed), and a de-
tailed description of the fish. The de-
scription was followed by a statement of
the fish’s distribution within and without
the state, a statement on average and
maximum lengths and weights, and infor-
mation on habitat preferences, food pref-
erences, and other phases of biology. For
most species, information was given on
how the fish might be caught and its value
(if any) as food. Many species were
illustrated by black and white photo-
graphs or by colored plates painted by
Mrs. Lydia M. (Hart) Green and Miss
Charlotte M. Pinkerton. These colored
plates were so fine that for nearly a half
century none published elsewhere was
their equal.
The second part, the atlas, contained
maps of the 10 stream systems of the
state. These maps showed the glacial ge-
ology of Illinois, localities from which
collections were made, and interior dis-
tribution of 98 of the most important
fishes.
As a state publication on fresh-water
fishes, The Fishes of Illinois remained
unique for a period of more than 40
years.
ILLINOIS RIVER PLANKTON
Kofoid’s studies of the plankton of the
Illinois River appeared as five articles in
volumes 5, 6, and 8 of the Bulletin of the
State Laboratory of Natural History.
Altogether Kofoid published nearly 1,000
printed pages on the plankton of the IIli-
nois River.
From 1895 to 1900 Kofoid was su-
perintendent of the biological station at
Havana. In 1900 he went to the Uni-
versity of California at Berkeley. At the
time he left Illinois for California and a
new position, he had published only three
short papers on plankton, one dealing
with methods and apparatus, one with a
168 Ittinois NarurAL History SURVEY BULLETIN
Vol. 27, Art. 2
Two members of the staff of the Illinois State Laboratory of Natural History making obser-
vations on the breeding habits of fish near Havana, 1910 or 1911. The box at the stern of the
boat was used by observers in watching the movements of fish and in searching for fish nests
and fry.
new species, and one with a new genus
of plankton (Kofoid 1897, 1898, 1899).
Two longer papers on plankton (Kofoid
1903, 1908), one on quantitative inves-
tigations and the other on constituent or-
ganisms and their seasonal distribution,
he wrote in California. Kofoid remained
on the staff at Berkeley until his retire-
ment in 1936.
BOTTOM FAUNA
R. E. Richardson’s classic studies of
the bottom fauna of the Illinois River
covered a period that coincided with se-
vere changes in the biology of the river
(Forbes & Richardson 1913, 1919; Rich-
ardson 1921, 1925a, 1925b, 1928). Be-
fore 1900 the Illinois was a reasonably
clean river receiving very limited organic
pollution from a small number of towns
along its banks. By 1900 Chicago had
become an important trading center and
was growing rapidly. In order to get rid
of the sewage and the organic waste from
a number of meat packing plants of Chi-
cago, a diversion channel was opened be-
tween Lake Michigan and the Des
Plaines River, one of the headwater
streams which united with the Kankakee
to form the Illinois. Forbes and Rich-
ardson had collected bottom fauna in the
Illinois prior to 1900, and Richardson
had continued to do so after the diver-
sion of Lake Michigan water had begun.
At first the organic pollutants created a
nuisance only in the upper part of the
river, at Morris, Marseilles, and Starved
Rock. Richardson studied the bottom
fauna throughout the length of the upper
part of the river in 1909, 1910, and 1911
and found that the river was nearly nor-
mal at Chillicothe and Hennepin. Above
these towns it became progressively more
polluted.
During the period 1900-1908 the or-
ganic pollutants acted as fertilizer, and
the annual fish yield of the lower part of
the Illinois increased from 11.5 million
to 24 million pounds. Gradually, after
December, 1958
1908, organic waste from Chicago in-
creased until the volume approached the
capacity of the river to oxidize it. Diver-
sion was increased, and the fish yield
dropped; a peak diversion occurred in
1927 with a flow of 10,245 cubic feet per
second (Mulvihill & Cornish 1930:57).
The period of maximum pollution oc-
curred between 1915 and 1920. From his
studies of bottom fauna during this time,
Richardson calculated a reduction in the
total weight of bottom organisms in the
reach from Chillicothe to La Grange of
34.5 million pounds, representing a po-
tential loss of 7 million pounds of fish.
By 1921 the fish yield of the river had
hit an all-time low of 4 million pounds,
partly from pollution and partly from ex-
tensive bottomland lake drainage. After
1922 there was some reduction of the raw
sewage going into the Illinois River, and
from 1924 to 1930 the yield of commer-
cial fish varied around 10 million pounds
per year.
Between 1913 and 1928, Richardson
(with some assistance from Forbes on two
of the early papers) published six articles
in the Bulletin series. Because of the op-
portune timing of his studies in relation
to the pollution of the Illinois, Richard-
son was able to set up a classification of
seven degrees of pollution based on the
presence of certain groups of aquatic or-
ganisms. These groups were often better
indicators of the degree of pollution than
were oxygen analyses, because the animal
associations were sensitive to small in-
creases in pollution, or to fluctuations in
pollution that might be missed unless
oxygen analyses were made continuously.
NEW LINES OF RESEARCH
During the second decade of the twen-
tieth century, biologists became interested
in measuring the effects of physical and
chemical changes in the aquatic environ-
ment upon fish, and in the responses of
the fish to these changes. From 1914 to
1925, members of the staff working in
aquatic biology published papers on the
suitability of bodies of water for fishes;
the poisoning of fishes by illuminating gas
wastes; the reaction of fishes to carbon di-
oxide and carbon monoxide; a collecting
bottle for quantitative determination of
BENNETT: AQuatic BIoLoGy 169
dissolved gases; methods of measuring the
dangers of pollution to fisheries; and ob-
servations on the oxygen requirements of
fishes in the Illinois River. These publi-
cations were the work of Victor E. Shel-
ford (1917, 1918a, 19185), Morris M.
Wells (1918), Edwin B. Powers
(1918), and David H. ‘Thompson
(1925). They represent a new approach
to fisheries studies, e.g., the use of labora-
tory studies to explain and expand the
knowledge of the relationships of fishes
and other aquatic organisms to their en-
vironments.
In the early 1920’s aquatic investiga-
tions were continued on the Illinois River,
where the Natural History Survey main-
tained a houseboat laboratory and attend-
ing boats and equipment. At this time
studies were begun on the lakes of north-
eastern Illinois, studies that included the
taking of quantitative plankton and _ bot-
tom samples and collections of fishes and
higher aquatic plants. In 1923, an inves-
tigation was begun also on the Rock River
(Forbes 1928).
Surveys on the Illinois River, made in
co-operation with the Illinois Water Sur-
vey in 1923 and 1924, showed that the
normal life of the river had been de-
stroyed by pollution as far down as Peoria
Lake.
By 1927 the staff had published in the
Bulletin 20 articles, comprising 1,856
printed pages, on Illinois River biology.
These articles apparently had had a pro-
found effect on aquatic biologists in many
parts of the United States; other states
were engaged in making their own lake
and stream surveys, for the most part not
so comprehensive as those of the Illinois
River, but adequate to give some informa-
tion on physical and chemical conditions
and rough measurements of the fish food
resources, plus inventories of the kinds
and relative abundance of fishes present.
At this time (1927) the Natural His-
tory Survey had expanded its own stream
survey program to include, besides the
Rock River, the Hennepin Canal, the
Sangamon and Kaskaskia rivers, and the
streams of Champaign County (Forbes
1928). The Rock River investigation
was operated from 1923 to 1927 with
David H. Thompson in charge of field
collecting and R. E. Richardson in charge
170 ILLINoIs NATURAL History SurRvEY BULLETIN
of the analysis of data at Urbana.
Thompson and three or four other men,
working steadily each year through spring,
summer, and fall, collected and shipped to
Urbana about 90,000 fishes of 90 species,
2,400 fish stomachs, 15,000 river mussels
belonging to 40 species, 820 collections of
small invertebrates, and 500 collections of
plankton and algae.
Samuel Eddy (1927, 1931, 1932)
worked on the plankton of Lake Michi-
gan and the Sangamon River and on
plankton collections from some sinkhole
ponds in southern Illinois.
EARLY MANAGEMENT
ATTEMPTS
Many of the early activities in the man-
agement of aquatic resources of the
United States were based on premises
which later research proved to be inac-
curate or erroneous. These included such
measures as stocking and the protection of
fish from human exploitation through re-
strictions in the form of fishing seasons,
length limits, and creel limits. Toward
the end of the last century, James Nevin
(1898:18), speaking before the American
Fisheries Society, made the following
statement:
Personally I have been on the various
spawning grounds of the whole chain of Great
Lakes from the Gulf of St. Lawrence to Lake
Superior during the spawning seasons; and |
have many times watched the salmon trout,
white fish and wall-eyed pike spawn in their
natural way; and I am convinced that only
a very small percentage of the eggs so de-
posited are fertilized.
This statement represented the attitude
of the hatchery supervisors and most ad-
ministrative personnel connected with
federal and state agencies dealing with
fisheries resources. As the spawning
grounds of most fishes of the Great Lakes
remain relatively unexplored even today,
it is doubtful if Nevin was very familiar
with them.
Ideas having no scientific basis often
become widely accepted. For example, al-
most everyone has heard that one should
wet his hands before handling a fish if
he wants it to remain alive after release.
Apparently this idea originated with
G. H. Thomson, Superintendent of the
Estes Park Fish Hatchery, Colorado.
Vol. 27, Art. 2
Thomson had cards printed with the
title, ““A Plea for the Fish.” The cards
stated:
When removing an undersized trout from
your hook, always moisten your hands before
grasping the fish; otherwise the dry hand
will remove the slime from the back of the
trout, when it is only a question of time until
fungus sets in and the fish will die.
Thomson distributed these cards to
residents of all states and of many foreign
countries. In 1912 he reported that at
the September 21—24, 1908, meeting of
the American Fisheries Society in Wash-
ington, D. C., the Society “recommended
that the various state commissions educate
the people by every means in their power
to follow the directions given about wet-
ting the hands” (Thomson 1913:171).
He reported also that his program was
endorsed by 28 fish and game commis-
sioners throughout the United States. His
idea was so widely disseminated that al-
most everyone has heard of it; yet
there is no evidence that any attempt
was made to test it through scientific
experimentation.
In spite of continued emphasis on arti-
ficial propagation, new techniques were
gradually discovered and put into use
by researchers in the fisheries field, and
these laid the foundation for modern
thought in management. Borodin (1924)
and Barney (1924) called attention to
the value of using growth rings on scales
and otoliths for determining the age of
fishes; Wiebe (1929) proposed the use
of fertilizers to increase plankton produc-
tion; Surber (1931) discussed the use of
sodium arsenite in the control of aquatic
vegetation; Burr (1931) used electrical
equipment to stun fish; Markus (1932)
investigated the relationship between
water temperatures and food digestion in
largemouth bass; through tagging and re-
covery, Thompson (1933a) studied mi-
grations of stream fishes. These and
other findings laid the groundwork for
modern attack on the problems of fish
management.
MODERN MANAGEMENT
The modern concept and use of the
term “fish management” first appeared
about 30 years ago. It was suggested
December, 1958
(if not named) by E. A. Birge in
writing about fish and their food. Birge
(1929:194) stated:
Good fishing for sport calls for the con-
tinued presence in a lake of a relatively few
large individuals of the desired _ species,
which are to be caught singly. They must
be larger than the average adult. They are
not caught primarily for food but for sport
and as a basis for stories. A dozen half-
pound bass are by no means an equivalent to
one three-pounder from this point of view.
But these large individuals are few in num-
ber: they are old and have come to full size
very slowly. It is easy to catch them and very
hard to replace them in the presence of the
vigorous competition for food that goes on
in a lake. And as yet little thought and less
study have been given to the needs of this
specific form of conservation of fish resources.
(Italics mine.)
This statement implies a concept of
management for sport fishing.
When Carl L. Hubbs described the
organization of the Institute for Fisheries
Research (Hubbs 1930), fisheries re-
searchers in Michigan were working on a
state-wide creel census, lake and stream
surveys, stream improvement, nursery
waters, fish migration, predators of fish,
fish diseases, and fish growth.
At about the same time, fisheries re-
search at the Illinois Natural History
Survey (Wickliff 1933) included studies
of fish migration through tagging of fish,
ages and growth rates of important fishes,
general quantitative determinations of
plankton and bottom organisms, a com-
parison of fish population densities by
means of standardized fishing methods,
and the determination of the fish popu-
lation of a lake by capture, fin marking,
and recapture of adult fish.
The point at which fish management
emerged as a more or less discrete dis-
cipline is not easily established. If fish
management is assumed to be the art of
producing sustained annual crops of wild
fish for recreational use (modified from
Leopold 1933), agreement as to the time
management began is difficult to reach.
Modern management could hardly
have made a beginning until biologists
had discovered enough basic information
about fishes to be able to discredit the
unfounded but strongly held theories
relative to the values of stocking, closed
seasons, length limits, and creel limits.
This basic information came from many
BENNETT: AQUATIC BIOLOGY 171
sources and was available before 1940. In
Ohio, Langlois (1937) was convinced
that the closed season was worthless for
increasing the numbers of bass. In Mich-
igan, Eschmeyer (1938) had _ poisoned
the entire fish populations of several
small lakes in which the fishing was poor
and had discovered an ‘‘overabundance of
fish” instead of a scarcity. Also in Mich-
igan, Carbine (1939) had _ investigated
the spawning and hatching of nest-build-
ing centrarchids in Deep Lake and had
discovered that many more young were
produced than the lake could support. In
Illinois, David H. Thompson had _ fol-
lowed dominant broods of crappies in
Lake Senachwine for 4 years (1933-
1936) and had come to the conclusion
that, while sizes and numbers of fish
varied, the total weight of the popula-
tion remained fairly constant. Also in
Illinois, Thompson & Bennett (1939c)
had demonstrated relationships between
length of food chains and poundages of
fish supported by ponds. In Alabama,
Swingle & Smith (1939) had demon-
strated the capacity of fish populations to
expand or contract in relation to the
capacity of the habitat to support them.
These researches on the dynamics of
fish populations formed the bases for
modern fish management. Yet old ideas
were difficult to uproot. Clarence R.
Lucas (1939) of the U. S. Bureau of
Fisheries published a paper titled ““Game
Fish Management,” in which he listed
what he termed the “operative” tech-
niques of fish management: (1) regula-
tion—closed seasons, bag limits; (2) fish
culture—rearing of game fishes for stock-
ing; (3) distribution—transportation and
liberation of hatchery-reared fish; (4)
stream and lake improvement; and (5)
predator control—the removal of preda-
tory fishes or of fishes that otherwise
interfere with the production of the game
fish crop. This paper reflected exactly
the old conception of operation, but under
a new name.
Thompson’s ideas on fish management
were summarized in his contribution to
A Symposium on Hydrobiology. In a sec-
tion titled ““The Fish Production of In-
land Streams and Lakes” ‘Thompson
(1941) stated that production and yield
were synonymous—both represented the
172
crop that was harvested. The total
amount of fish in a lake or stream at any
given time was the standing crop; when
the standing crop reached “saturation”
it represented the carrying capacity of the
lake or stream. Thompson believed that
the food resources and the carrying ca-
pacity of a body of water remained fairly
constant but that the number of fish
could vary widely. He reasoned that, if
the weight of fish remained constant, then
the removal of some fish would furnish
more food per individual for those re-
maining, and the growth rate would in-
crease; if more fish were planted, less
food would be available per individual,
and the growth rate would decrease. ‘To
further this thesis, he was able to demon-
strate from his own laboratory experi-
ments that at a water temperature of 70
degrees F. a 10-inch bass required as food
an amount of minnows equal to three-
fourths of 1 per cent of its body weight
per day in order to maintain a constant
weight; and that, at an optimum feeding
rate, 2.5 pounds of minnows were re-
quired to produce 1 pound of bass.
Complete censuses of nine Illinois lakes
subject to floods and indiscriminate stock-
ing showed that, although 46 different
species were present, only 10 species of
fish comprised more than 1 per cent each
of the total weight of all fish. The rough
fish listed were redmouth buffalo, mon-
grel buffalo, and carp; forage fish were
gizzard shad and golden shiner; catfish
included only the black bullhead; the pan
or fine fish were bluegill, white crappie,
and black crappie; and the only game
fish was the largemouth bass. These
species must be considered as showing
superior adjustment to the pond habitat
in Illinois.
Thompson had observed cycles in fish
that were the result of interspecific and
intraspecific competition. The ‘“‘fine’’ fish
in Lake Senachwine (Illinois) amounted
to about 50 to 55 pounds per acre, regard-
less of the number of fish or the area of
the lake. In some years there were 10
times as many fish as in other years, and
the individual fish averaged one-tenth the
weight of the individual fish of other
years. Large broods of crappies were pro-
duced at intervals of about 4 years, and
during interim seasons they controlled the
I~ttinois NaturAL History Survey BULLETIN
Vol. 27, Art. 2
survival of their own young and the
young of other species.
Thompson attempted to construct a
theoretical maximum cropping rate for
any water area as a percentage of its
carrying capacity. He believed that the
cropping rate was related to latitude
(length of growing season). He estimat-
ed annual cropping rates for Vilas Coun-
ty and Madison, Wisconsin; Urbana and
Cairo, Illinois; Memphis, ‘Tennessee;
Jackson, Mississippi; and New Orleans,
Louisiana. He assumed that in northern
Wisconsin about 21 per cent of the carry-
ing capacity could be replaced each year;
in New Orleans the replacement could
be as much as 118 per cent; other loca-
tions fell between these extremes.
Thompson also presented the idea that
fish predators were probably beneficial, al-
though he gave no data to back this
assumption.
THE LAST TWENTY YEARS
With the death of Robert E. Richard-
son in 1935, the aquatic biology staff of
the Illinois Natural History Survey was
reduced to Thompson and one full-time
field assistant; however, several graduate
students were working under Thomp-
son’s direction. At that time, Thompson
was interested in beginning some pond
management investigations. As a result
of a policy of expansion for the Section
of Aquatic Biology, I was employed on
January 1, 1938, to work with Thompson
on ponds. To gather experience in a
new censusing technique that involved
poisoning fish with rotenone, a technique
developed by R. W. Eschmeyer in Mich-
igan, Thompson and I made a trip to Ann
Arbor, where Eschmeyer was censusing
several small Michigan lakes. We helped
in one of the censusing operations and
were served some of the poisoned fish at
the home of Dr. Carl L. Hubbs.
Returning to Illinois, we (with the
help of Donald F. Hansen) began cen-
susing ponds, one of the first of which
was Homewood Lake, a 2.8-acre pond
on the property of the Homewood Fishing
Club on the outskirts of Decatur, Illinois.
From the standpoint of public relations,
the operation was a huge success. The
pond contained mostly carp, buffalo, giz-
——— ss
December, 1958
zard shad, and stunted bluegills; all day,
local sportsmen slipped through the un-
derbrush to spy on the “fish killers,” but,
seeing few, or no, dead useful hook-and-
line fish, they stayed to help us collect
the outsized carp and buffalo.
Through the able assistance of Sam A.
Parr, at that time Investigator for the
Department of Conservation for Macon
County, we were able to census 22 arti-
ficial lakes and ponds in central and
southern Illinois. One of these ponds
was Fork Lake, owned by Paul S. Smith
(formerly Chief Inspector with the De-
partment of Conservation), who gave us
carte blanche use of the pond. ‘These
censuses, and the studies of the fish popu-
lations that replaced those poisoned in
these ponds, led to the publication of three
reports on lake management (Thompson
& Bennett 1939a, 1939b, and Bennett,
Thompson, & Parr 1940) and two articles
of the Bulletin, ‘Management of Small
Artificial Lakes” (Bennett 1943) and
“The Bass-Bluegill Combination in a
Small Artificial Lake” (Bennett 1948).
Censuses of the ponds, most of which
were poor fishing waters, brought out the
fact that overpopulation and stunting
and/or large numbers of fish of undesir-
able species, rather than a lack of fish,
were the causes of poor fishing. In fact,
one of the poorest ponds for fishing was
found to contain 1,145 pounds of fish per
acre. At Fork Lake (‘The Bass-Bluegill
Combination in a Small Artificial Lake’’),
we attempted to crop heavily the large-
mouth bass and bluegills in this 1.4-acre
pond; we used six fyke nets of 1-inch-
mesh, set with leads to completely block
off the pond into sections. When these
nets were fished for 10 days each month
from March to November of each year
for 3 years, we discovered that we could
not crop the bass because they refused to
enter the nets, and the constant cropping
of bluegills contributed to the well-being
of both species. This discovery led to the
belief that anglers had nothing to fear
from commercial fishing operations.
In July of 1938 Hansen was given
charge of the scale collections for study-
ing age and growth of fishes and the task
of investigating the fish populations of
water supply reservoirs where fishing was
an important secondary function to water
Bennetr: AQUATIC BIOLOGY 173
supply. At that time he was operating
fyke nets at Lake Decatur and in other
waters in order to gather material for a
life history study of the white crappie
(Hansen 1951).
In the late 1930’s and the early 1940's
federal agencies were engaged in con-
struction projects under various work
programs. ‘The Natural History Survey
was to benefit from these programs
through the construction of a laboratory
located on the Chautauqua National
Wildlife Refuge, near Havana, and a
laboratory and artificial lake in Fox
Ridge State Park, near Charleston. The
Havana laboratory, completed in early
1940, became the headquarters for water-
fowl and fishery research on the Illinois
and Mississippi rivers. ‘The laboratory
and lake in Fox Ridge State Park were
completed in 1941 and became a center for
studies on largemouth bass management.
About the same time the U. S. Forest
Service constructed two lakes in the
Shawnee National Forest in the southern
part of Illinois. These were Pounds Hol-
low Lake, near Gibsonia, and Lake Glen-
dale, near Dixon Springs; the latter has
been used by the Natural History Sur-
vey as a study area since it was first
stocked in 1940. Lake Glendale is located
in a region of low soil fertility and is
fairly typical of impoundments in forested
lands. Hansen has found that the lake
produces excessive populations of both
bass and bluegills, and that fishing may
be improved at intervals by the removal
of part of the population of both of these
species.
In 1942 Thompson and Hansen made
a fish survey of the Illinois River from
Channahon to the river mouth at Graf-
ton. About 34,000 fish were studied,
most of which were caught in hoop or
fyke nets. Many of the carp in the upper
part of the river (particularly at all sta-
tions above Henry) showed the knothead
abnormality which was an indication of
gross pollution. At Channahon 94.8 per
cent of the catch was composed of
“rough” fish, most of them carp or gold-
fish. In contrast, at the Creve Coeur
station below Peoria, 88.4 per cent of the
fish taken were “‘fine” fish (most of them
white crappies or black crappies) and
only 6.0 per cent were “rough’’ fish.
174 Intinois NATURAL History SuRVEY BULLETIN
In December, 1943, conservation representa-
tives from the states of Illinois, Iowa, Mis-
souri, Minnesota, and Wisconsin, from the
United States Fish and Wildlife Service, and
from other interested agencies met at Dubuque,
lowa, and formed the Upper Mississippi River
Conservation Committee (Smith 1949). This
group was organized for the purpose of spon-
soring studies of the fishery and wildlife re-
sources of the Mississippi River from Ca-
ruthersville, Missouri, to Hastings, Minnesota.
The studies were designed to serve as a basis
for making scientifically sound recommenda-
tions for the management of these resources
(Barnickol & Starrett 1951:267).
Field operations in the Missouri-Illi-
nois section were begun in March, 1944,
with the Conservation Commission of
Missouri, the Illinois Department of Con-
servation, and the Illinois Natural His-
tory Survey participating. A crew con-
sisting of four men, working from the
Natural History Survey’s laboratory boat
Anax, operated test nets and other types
of fishing gear at 19 stations between
Caruthersville, Missouri, and Warsaw,
Illinois. two years later, in 1946, field
operations were resumed in the Iowa-lIlli-
nois part of the river with the Iowa Con-
servation Commission and the two IlIli-
nois agencies co-operating. The survey in
1944 was begun with Thompson in
charge of the laboratory boat and Paul G.
Barnickol as the chief fisheries investi-
gator for Missouri. Thompson resigned
from the Natural History Survey to go
with the Forest Preserve District of Cook
County, and in May, 1945, Barnickol
was employed to replace him. Barnickol
was in charge of the crew that covered
the upper part of the river from Burling-
ton to Dubuque in 1946. In May, 1948,
Barnickol was recalled to Missouri to be-
come Head of Fisheries Research for the
Conservation Commission. At that time
data from 2 years of field work on
the Mississippi River were only partly
analyzed.
On July 1, 1948, William C. Starrett
began employment by the Natural His-
tory Survey for the difficult task of work-
ing over Mississippi River fishery data
collected by others. In this he had the
co-operation of Barnickol; their combined
efforts resulted in publication of two
articles of the Natural History Survey
Bulletin: “Commercial and Sport Fishes
of the Mississippi River Between Caruth-
Vol. 27, Art. 2
ersville, Missouri, and Dubuque, Iowa”
(Barnickol & Starrett 1951) and “Eff-
ciency and Selectivity of Commercial Fish-
ing Devices Used on the Miaississippi
River” (Starrett & Barnickol 1955). The
first of these articles listed the fishes
caught in the Mississippi River, their
distribution, size range, growth rates,
and other information on their biology.
A total of 26,037 fish weighing 28,294
pounds were taken in 1944 and 1946.
The second article presented a statistical
study of the efficiency and selectivity of
various types of gear used in the Mis-
sissipp1 River survey. The study was
made for the purpose of furnishing infor-
mation to those assigned the task of man-
aging the river’s commercial fishery. It
included a consideration of seines, tram-
mel nets, basket traps, wing nets, hoop
nets, trap nets, and trot lines, the kinds
of fish most commonly captured or
trapped, the sizes of fish taken with
various mesh sizes, and the comparative
efficiency of several types of gear.
One of the interesting findings to come
out of the Mississippi River survey was
the collection of post-larval paddlefish,
Polyodon spathula (Wal.), by Thomp-
son and Barnickol. While minnow sein-
ing off a sand bar in the Mississippi near
Cape Girardeau, Missouri, on May 29,
1944, the Thompson and Barnickol party
took four paddlefish ranging in length
from 17 to 26 mm. Other than the col-
lection of seven paddlefish larvae (17—20
mm.) taken by Thompson in 1933
(Thompson 1933b), these are the only
young paddlefish of less than 35 mm. in
length known to have been collected.
These post-larval paddlefish and other
paddlefish material were studied by R.
Weldon Larimore (1949, 1950), who de-
scribed the changes in the cranial nerves
of the paddlefish accompanying develop-
ment of the rostrum and gametogenesis
of Polyodon and its relationship to prac-
tical regulation of the paddlefish fishery.
In 1948 Larimore was made a per-
manent member of the Aquatic Biology
staff. He had already nearly completed
a study on the life history and ecology
of the warmouth, Chaenobryttus gulosus
(Cuvier), a fish that was being consid-
ered as a possible companion species for
largemouth bass in ponds. This study of
December, 1958
the warmouth was later published as an
article of the Natural History Survey
Bulletin (Larimore 1957).
During the summer of 1950 Larimore,
with the help of Leonard Durham and
others, began an intensive investigation
of the fishes in Jordan Creek, a small
spring-fed, upland stream in Vermilion
County. This project marked the _ be-
ginning of upland stream investigations
as a continuous program of the Section
of Aquatic Biology. Through the use of
the electric seine and other special equip-
ment developed for stream work, it has
been possible to make both intensive and
extensive studies on the ecology of stream
fishes in the central Illinois region (Lari-
more, Pickering, & Durham 1952). The
smallmouth bass, Micropterus dolomieui
Lacépéde, was found to be the most im-
portant anglers’ fish in these streams.
The fry of this bass were particularly
vulnerable to floods on streams when the
floods were accompanied by — sudden
changes in water temperatures. The adult
BENNETT: AQUATIC BIOLOGY 175
bass showed well-developed homing in-
stincts as did some other species (Lari-
more 1952). Tests of the value of plant-
ing 6— to 8-inch smallmouths in a
stream already containing a population of
smallmouth bass demonstrated that it
was possible to build up numbers of these
fish only temporarily. Minnows removed
from a stream with an electric seine were
replaced by other minnows through mi-
gration and reproduction within a period
of a few months (Larimore 1955). Ap-
parently streams are quickly repopulated
even when fish are killed by drought con-
ditions, heavy winter ice, or temporary
severe pollution.
In studies of ponds and lakes, by 1945
evidence had accumulated to substantiate
the idea that a lack of fish predators was
an important problem to be faced in the
management of these waters. Obviously,
fishing was no substitute for natural pre-
dation, and much of the task of the fish
manager was that of functioning as a
predator of small fishes (Bennett 1947).
Fisheries technicians of the Illinois Natural History Survey using fish shocker for sampling
the population of a stream. The shocker is a recent development that has been used successfully
in both streams and lakes.
176
Studies on the effects of fish predators
were begun with the placing of six short-
nosed gars in a l-acre pond containing
bass and bluegills; in this pond, bluegills
were constantly in a state of overpopula-
tion. Because the short-nosed gars were
unable to reproduce in the pond, their
numbers were easily controlled. From
this experiment, Durham (1955) expand-
ed the investigations of fish predation to
include about a dozen additional ponds
containing populations of stunted fish.
Using gars and cormorants as predators,
he was able to show improvement in
growth and size of fish and an improve-
ment in the survival rate of naturally
produced bass.
Ten years of recording catches of fish-
ermen at Ridge Lake (Bennett 19542)
gave a yield figure of more than 11,000
largemouth bass following an_ original
stocking of 435; the fact that, in the last
6 years of the 10, 155,000 bluegills had
been removed following an original stock-
ing of 129 of these fish indicated that the
bluegills were not only more prolific but
showed a higher survival rate than the
bass. The annual hook-and-line yield of
bass varied between 10.9 and 30 pounds
per acre, although the lake was not con-
sidered a highly fertile one. During this
time the standing crop of bass varied be-
tween 30 and 50 pounds per acre. The
success of a bass spawn (and survival)
was negatively correlated with the num-
bers of yearling fish present in the lake,
particularly yearling bluegills. Young
bass surviving to post schooling fry stage
had about 1 chance in 35 of living to
reach a size of 7 to 10 inches; natural
mortality remained relatively high until
the fish reached an average weight of
0.75 pound; then it dropped to less than
5 per cent per year until fish reached
ages of 7 to 8 years, when the natural
death rate again became high. With the
system followed at Ridge Lake of culling
the fish population at intervals of 2 years,
the average length of bass at the end of
the first growing season was 7.5 inches,
at the end of the second growing season
10.8 inches, and at the end of the third
13.0 inches. The single most important
finding at Ridge Lake was that a large
new year class of bass could be produced
at any spawning season by reducing the
I-ttinois NaturaAL History SurvEY BULLETIN
numbers of small bluegills in the lake
prior to the spawning period. This re-
duction could come about through arti-
ficial culling of the fish population, or, as
was later discovered, through concentrat-
ing the fish during the fall months pre-
ceding the bass spawning season by re-
leasing a large proportion of the water
from the lake and then allowing the lake
to refill over winter. Studies of the ef-
fects of these water releases, or draw-
downs, were begun in 1951 (Bennett
1954b) and they are still in progress.
Swingle & Smith (1942), working on
fishes in Alabama ponds, built their man-
agement practices around a program of
pond fertilization; they recommended
fertilization for ponds in other parts of
the country. In order to test the useful-
ness of fertilization as a pond manage-
ment technique in Illinois, Donald F.
Hansen began a testing program in ponds
Vol. 27, Art. 2%
7
located on the University of Illinois Ex- —
perimental Farm near Dixon Springs in
southern Illinois, where soils are as poor
as any within the state. After 7 years of
fertilizing three ponds at various rates
with complete fertilizers and using three
other similar but unfertilized ponds for
controls, Hansen concluded that the im-
provement in fishing did not justify the
cost of the fertilizer, if fish were cropped
by hook-and-line. The unfertilized or con-
trol ponds furnished better bass fishing
than the fertilized ponds. Bluegills could
be caught at a more rapid rate in the
fertilized ponds, and the fish averaged
larger in size. In terms of extra fish flesh
produced by the fertilizer, the improved
fishing cost about $1.00 per pound of
fish.
‘Tests on various combinations of fishes
in ponds have been going on for many
years (Bennett 1952). The combinations
used include largemouth bass—bluegill;
largemouth bass—bluegill-warmouth—black
bullhead; largemouth bass—bluegill—war-
mouth—channel catfish; largemouth bass—
golden shiner; largemouth bass—redear;
largemouth bass-warmouth; largemouth
bass-short-nosed gar; largemouth bass—
bluegill-short-nosed gar; smallmouth bass
alone; and largemouth bass alone. No
combination appeared to be ideal, although
several combinations proved to be as pro-
ductive of good fishing as the highly ad-
December, 1958
vertised largemouth bass—bluegill combi-
nation.
Redear sunfish, Lepomis microlophus
(Gunther), were not reported from IIli-
nois prior to 1945. In that year Dr. C.
L. Schloemer, then located at Denton,
‘Texas, sent a small number of adult red-
ears to the Natural History Survey at
Urbana. These fish were placed in sev-
eral ponds near Urbana, but none ap-
parently survived the winter of 1945-46.
In the spring of 1946 Dr. William E.
Ricker, then located at Bloomington, In-
diana, furnished 30 large adult redears
from central Indiana. These fish were
planted in several locations; 12 were
placed in a stripmine pond, near Danville,
that contained largemouth bass. ‘The
redears in the stripmine pond multiplied
very successfully and were the source for
introductions into many lakes and ponds
scattered through central and southern
Illinois. Redears are now present in tribu-
taries of the Illinois River (particularly
the Sangamon) and in the Wabash drain-
age along the eastern border of the state,
as well as in the Big Muddy system of
southern Illinois. As far as is known, all
of these fish originated from the 12 fish
released in the pond near Danville.
In 1949 Starrett was placed in charge
of the Natural History Survey labora-
tory at Havana, where he began a study
of Lake Chautauqua, a shallow flood
plain lake of some 3,000 acres belonging
to the U. S. Fish and Wildlife Service
and used principally as a_ waterfowl
refuge. This lake was fairly typical of
other areas in the Illinois valley that had
been leveed to keep out the river, pumped
dry so that they could be used for farm-
ing, and later flooded. We wondered
about comparative over-all values of these
areas for recreation (duck hunting and
sport fishing), fish production (com-
mercial fishes), fur production (native
furbearers), and timber production
(wood pulp), as contrasted with values
of these areas for corn production that
required government help in the con-
struction and maintenance of _ levees,
pumping costs and equipment, and sup-
port of corn prices. In spite of the fact
that recreational values are often intangi-
ble, it soon became evident that the value
of this area for fishing and recreational
BENNETT: AQUATIC BIOLoGy U7)
activities by people in the nearby indus-
trial towns of Pekin and Peoria were
much greater than the value of the corn
the lake bottom would produce if the
lake were drained (Starrett & McNeil
1952). In addition to studies in recrea-
tional values, Starrett has made intensive
studies of the fish and bottom fauna of
Chautauqua and similar lakes, and the
physical, chemical, and biological factors
which influence them. Through the as-
sistance of biologists from the Illinois
Department of Conservation he has col-
lected annual commercial fishing sta-
tistics on all of the large Illinois rivers
and information on native lamprey dis-
tribution.
In many of our operations during the
past 20 years we have had the co-opera-
tion of the Illinois Department of Con-
servation: in pond management studies,
stream investigations, surveys of the
fishes of large rivers, and statistical studies
on yields of commercial fishes. Some-
times this assistance has been in the form
of funds for construction works or for
physical equipment, sometimes for half-
time or full-time assistants; occasionally
personnel of the Department have par-
ticipated in operations requiring many
men for a short period of time. This co-
operation has not been based on written
agreement; rather, it has come about
through an understanding of mutual
needs and interests by certain personnel
of the Department, particularly Sam A.
Parr, formerly Investigator, Inspector,
and Superintendent of Fisheries, now
Administrative Assistant to the Director
of Conservation; and William J. Harth,
recently made Superintendent of Fish-
eries. We are grateful for this assistance
and co-operation.
DIRECTION OF FUTURE
STUDIES
In looking toward the future we find
that some lines of research are taking
shape now and others are still in the
planning stages.
One program that was begun in the
spring of 1958 centers on a study of
such basic concepts of .fish management
as carrying capacity and standing crop,
as well as the effects of cropping and
178 I-tinois NATURAL History SuRVEY BULLETIN
stocking on populations of fishes. This
work is centered at the Fin ’n’ Feather
Club near Dundee.
At the Eighteenth North American
Wildlife Conference held in Washington,
D. C., in 1953, Max McGraw, Presi-
dent of the North American Wildlife
Foundation, suggested the development of
a fisheries research unit at the Fin ’n’
Feather Club. It was agreed that the
McGraw Foundation (with the assist-
ance of the Illinois Department of Con-
servation) would develop a research unit
of at least 15 l-acre ponds and provide
space for laboratory and offices in the
Fin ’n’ Feather Lodge. When this would
be accomplished, the laboratory and pond
unit would be assigned to the North
American Wildlife Foundation, which in
turn would assign the use of the facility
to the Illinois Natural History Survey
and the Illinois Department of Conserva-
tion for fisheries research. Some progress
had been made in physical plant con-
struction by 1956, and on February 1 of
that year David Homer Buck was em-
ployed by the Natural History Survey to
give immediate supervision to the project.
Soon after, Maurice A. Whitacre, biolo-
gist with the Department of Conserva-
tion, was assigned to this program to
work with Dr. Buck. At the beginning
of the 1958 season 11 ponds were ready
for use. Eight other ponds are in various
stages of construction, and as these are
completed they will be stocked and added
to the units in operation.
A second program, already begun, has
to do with studies of the biochemistry
of fishes. A chemical laboratory was de-
veloped in conjunction with the aquarium
laboratories in the Natural Resources
Building at Urbana, and Robert C. Hilti-
bran was employed on May 1, 1957, to
begin biochemical investigations. Hilti-
bran was forced to pioneer in this field
because little research had been done on
fish biochemistry. He has begun by
studying the “normal” enzyme systems
of the bluegill, Lepomis macrochirus Ra-
finesque. Once the “normal” enzyme sys-
tems are known, Hiltibran will measure
the action of various chemicals on these
Vol. 27, Art. 2
systems: waste products from commercial
chemical processes and substances applied
to aquatic areas for the control of noxious
animals and plants. From these studies
he may be able to suggest methods of re-
ducing the toxicity of these chemicals to
fishes and other aquatic organisms.
Prior to 1934 Wilbur M. Luce (now
Professor of Zoology, University of IIli-
nois) and David H. Thompson developed
a method for stripping and fertilizing
sunfish eggs, which they used to produce
hybrids between species of these centrar-
chids. Luce raised many of these sunfish
to maturity, and Thompson recognized
that two of the hybrids were similar to
fish pictured by Forbes & Richardson
(1908) as being valid species. Recently
we have revived the technique of artificial
insemination of sunfish eggs in order to
explore the possibility of developing hy-
brids for use in fish management. In
1957. William F. Childers produced
viable fry from all possible combinations
of crosses of bluegills, redears, green sun-
fish, and warmouths. Some of these com-
binations appear to be superior to parent
types.
It is probable that within the next few
decades great advances will be made in
the management of fish populations for
sport and commercial uses. Research
basic to this management may lead to the
discovery of ecological factors which con-
trol the expansion of populations of im-
portant sport species, such factors as
have already been found for the large-
mouth and smallmouth basses. Adjust-
ments of these factors may be, to some
extent, applicable to most natural waters,
but they probably will be more practical
in artificial waters and in controllable
natural waters. It seems reasonable to as-
sume that progress will be made in en-
vironment control until waters can be
made to produce crops of selected plants
and animals much as terrestrial habitats
can be made to produce wheat, rice,
swine, and cattle. The development of
water management may not only give
ways to control the kinds and numbers of
fishes but also to control the individual
steps in the food chains of fishes.
Wildlife Research
ILDLIFE was high on the scale
of human values during the period
of discovery and initial settlement in IIli-
nois. When the Illinois Natural History
Society was founded in 1858, most II-
linoisans were self-reliant farmers who
measured values in terms of the length of
fences constructed, the acreage of cleared
forest land, the acreage of land under
cultivation, and the extent of drainage
programs, roadways, and railroads. The
Illinois Central Railroad line from Chi-
cago to the junction of the Ohio and Mis-
sissippi rivers had been completed only 2
years earlier. Representative of the period
are the reflections of Benjamin F. John-
son, chairman of a committee for the
examination of farms and nurseries for
the Illinois State Agricultural Society. In
reporting on improvements in “northern
Illinois” following inspections in 1859 by
the committee, Johnson (1861:84) un-
doubtedly impressed members of the So-
ciety when he stated that
the progress of improvement in this portion
of Illinois is little less than wonderful. Ten
years ago much of the country was wild, open
prairie; now there is scarcely a rood of un-
inclosed land, except portions of the timber
along the rivers and streams.
‘Today one cannot help but ponder why
there weren’t a few rebels hardy enough
to stand against the surge of progress and
insist that Illinois, the settlers’ ‘prairie
state,” set aside a prairie park or primitive
forest for future generations.
The loss of primitive areas and much of
what went with them was accepted as
inevitable. Even Dr. Stephen A. Forbes
(19124:40), a giant among the naturalists
of the time, pointed out that the reduc-
tion and elimination of wildlife through
settlement of Illinois by white man
has evidently been a perfectly natural and
inevitable one—as much so as the flow of
the tide in the wake of the revolving moon
—and immensely advantageous, also, from
every point of view except that of the in-
adequate, incompetent and ill-adapted popu-
lation which it [settlement] has reduced or
suppressed.
Te OVA S 1G a CO) aa
Dr. Theodore H. Frison (1938:19),
who knew and understood Forbes as well
as anyone, quoted the above statement as
representative of the philosophy of 1912.
DEVELOPMENT
Wildlife research, as it is recognized to-
day, first became evident in the annals of
the Natural History Survey in the late
1870’s when Forbes initiated his inves-
tigation of the food of birds. O. B. Ga-
lusha (1881:238) provided insight into
the conception of this research when,
following Forbes’ presentation of a paper
on the food of meadowlarks at the Janu-
ary, 1881, meeting of the Horticultural
Society of Northern Illinois, he observed
that when a few of us, six years ago, met in
the Normal University, as a committee of the
State Horticultural Society, to inaugurate the
enterprise, I had serious fears that the work
was too great for accomplishment.
These studies accompanied and _ prob-
ably assisted in the accomplishment of the
reorganization which converted the IIli-
nois Museum of Natural History into a
State Laboratory of Natural History on
July 1, 1877. The reorganization was ac-
companied by a new conception of pur-
pose, relieving the members of the staff
of the preparation of museum displays and
allowing them to concentrate on research.
Although I have been unable to uncover
direct evidence of it, I feel certain that
the change was manipulated by Forbes
and members of the Illinois State Horti-
cultural Society. Of legislative action ap-
proved May 29, 1879, to become effective
July 1, 1879, Forbes (1880f:1) gener-
ously reported:
We were also directed to investigate the large
and intricate subject of the food of birds, in
the interests of agriculture and horticulture,
$200 per annum being voted for the expenses
of this work.
Forbes’ research on the food of birds
was to become one of the outstanding con-
tributions to avian biology. This research
[ 179 ]
180
provides us with further insight into the
motivations of the man who guided the
program of the Natural History Survey
and its parent organizations for many
years (1872-1930). I have come to be-
lieve that wildlife research made such an
auspicious start in the Survey program not
only because of Forbes’ professional quali-
fications but also because of his intense
desire to contribute to knowledge relating
to human economy and welfare. W. L.
McAtee (1917:249) believed that F. E.
L. Beal and Forbes were “the founders
of the scientific method of studying the
economic value of birds.” Birds in Their
Relations to Man (Weed & Dearborn
1903) is inscribed ‘“To Stephen Alfred
Forbes . . . whose classic studies of the
economic relations of birds will long re-
main the model for later students.”
In an early report Forbes (1882a:1)
advised :
The work of the State Laboratory of Natural
History . . . is essentially that of a zoological
and botanical survey of the State, conducted
with principal reference to economic questions,
and to the interests of public education.
Although economic consideration con-
stituted a principal responsibility, such a
responsibility is adequately met only when
men are willing to meet it and are capable
of meeting it. If the desire had not been
there, it seems likely that Forbes and his
associates would have been content to
occupy themselves with the systematics
and descriptive records of the native flora
and fauna, and wildlife research would
have had to find its beginning at a much
later date. I marvel at the courage of
Forbes’ convictions when I consider the
statement of Robert Ridgway (1901:1),
a close associate of Forbes, on a prevailing
attitude of the day:
There are two essentially different kinds of
ornithology: systematic or scientific, and pop-
ular. The former deals with the structure and
classification of birds, their synonymies and
technical descriptions. The latter treats of
their habits, songs, nesting, and other facts
pertaining to their life-histories. . . . Popular
ornithology is the more entertaining, with its
savor of the wildwood, green fields, the river-
side and seashore, bird songs, and the many
fascinating things connected with out-of-door
Nature. But systematic ornithology, being a
component part of biology—the science of life
—is the more instructive and therefore more
important.
Ittinois NaturAL History SurvEy BULLETIN
Vol. 27, Art. 2
It is unfortunate that Forbes’ responsi-
bilities were such that he could not have
devoted more time to wildlife research,
for he seems to have possessed an under-
standing of wildlife biology which was
much in advance of his time. In a single
early paper (Forbes 1880a), a number of
observations were made which, by their
earliness, seem prophetic of views which
are credited to relatively recent times.
Current beliefs on predation may be seen
in “the annthilation of all the established
‘enemies’ of a species would, as a rule,
have no effect to increase its final average
numbers” (Forbes 1880a:11).
Forbes (1880a:8) recognized a need
for an understanding of animal popula-
tions long before they received serious
study. Of this he wrote:
Our problem is, therefore, to determine how
these innumerable small oscillations, due to
imperfect adjustment, are usually kept within
bounds—to discover the forces and laws
which tend to prevent either inordinate in-
crease or decrease of any species, and also
those by which widely oscillating species are
brought into subjection and reduced to a
condition of prosperous uniformity.
It is apparent that this view implies
population management in the modern
sense. Further implications of manage-
ment may be seen in the following
statement by Forbes (1880a:4) :
It is also plain that if man understands clear-
ly the disorders which arise in the system of
Nature as a result of the rapid progressive
changes in his own condition and activities,
and understands also the processes of Nature
which tend to lessen and remove these dis-
orders, he may, by his own intelligent inter-
ference, often avoid or greatly mitigate the
evils of his situation, as well as hasten their
remedy and removal.
Forbes (1880a:9) seems to have been
well on the way toward an understanding
of density dependent factors as used by
today’s students of animal populations, as
well as modern views on predation, when
he wrote: “The fact of survival is there-
fore usually sufficient evidence of a fairly
complete adjustment of the rate of re-
production to the drains upon the
species.” That his understanding of the
effect of density dependent factors on
animal populations was astonishingly
well advanced is evident in his (Forbes
18824:122) reasoning that excessive pop-
ulations are, “in one way or another, self-
ui
December, 1958
limiting.” Earlier he (Forbes 1880a:5)
had written that ‘as a general rule, the
rate of reproduction is in inverse ratio
to the grade of individual development
and activity; . . .’ The “grade of indi-
vidual development and activity” refers to
the degree of evolutionary progress from
a primitive form. Forbes (1880a:11)
seems to have been grasping at the role of
density independent factors in population
control when he observed that the “real
and final limits of a species are the inor-
ganic features of its environment,—soil,
climate, seasonal peculiarities, and the
like.”
What is today recognized as wildlife
research continued to develop under
Forbes’ guidance in the form of bird
censuses. The results of these censuses are
classics in American ornithology. They
constituted the first extensive, quantita-
tive investigations of bird numbers, or of
any wildlife population for that matter,
and introduced a census technique.
Despite Forbes’ modern views, there is
little evidence that he promoted wildlife
management to any great extent. The
thinking of Forbes (1912b:40) with re-
spect to game management, despite earlier,
more promising views, seems to have been
limited to the encouragement of restric-
tive laws, as evidenced by the following:
“Our resident game birds would all have
been gone long ago if it had not been for
the restraints of law put upon the ac-
tivities of the hunter... ” Forbes
(1912b:46) made a plea for the Illinois
Academy of Science to support by resolu-
tion the “Anthony bill” (Migratory Bird
Act of 1913), then under consideration in
the House of Representatives. It should
be remembered that legal protection was
virtually the only management concept of
the times.
ORGANIZATION
Game research in the modern sense be-
gan to receive recognition in the Natural
History Survey’s program in the early
1930’s. Probably stimulation was re-
ceived from the federal government’s
emphasis on conservation of natural re-
sources, an emphasis that accompanied the
search for work during that period of
national economic emergency, and from
Scorr: WILDLIFE RESEARCH 181
the influence of Herbert L. Stoddard
(1931) and Aldo Leopold (1931, 1933).
By that time, progressive leaders in the
field realized that restrictive regulations
and game farms were not meeting wild-
life management needs. Also, it had be-
come apparent that game _ populations
could be managed wisely only when man-
agement practices were based on a fund
of pertinent and precise knowledge. Fri-
son, who became Acting Chief of the IIli-
nois Natural History Survey upon Forbes’
death on March 13, 1930, and then Chief
on July 1, 1931, was among these leaders.
An enthusiastic hunter, Frison had a con-
suming interest in game management.
Wildlife research was recognized in the
organizational structure of the Natural
History Survey for the first time when
Frison (1938:31) established a Section
of Game Research and Management on
July 1, 1934. Dr. Ralph E. Yeatter, one
of the nation’s first game specialists, was
employed in this section.
Frison initiated formation of the now
well-established Midwest Wildlife Con-
ference, and the first meeting was held
in Urbana on December 5, 6, and 7, 1935.
This meeting, known as the North Cen-
tral States Fish and Game Conference,
was the first regional conference of wild-
life technicians in the United States.
Frison (1938:27) described the confer-
ence as
essentially a fish and game clinic at which
scientists from all the north-central states,
without being dominated by administrators or
the political type of conservationists, freely
discussed wildlife management practices in
an effort to winnow out the chaff from the
wheat, to coordinate such researches and to
orientate scientific studies of wildlife re-
sources in such a way that demonstrable
sound management practices would result.
By 1936 Frison (1938:31) had con-
cluded that experimental wildlife areas
were needed for the purpose of testing
management theories under practical con-
ditions, a need which has still not been
adequately met. A Section of Wildlife
Experimental Areas was listed on the
staff page of the Bulletin from March,
1938, to September, 1945. On June 1,
1938, a special program dealing with for-
est problems in game management was un-
dertaken by Dr. Lee E. Yeager, who had
joined the staff in the Section of Forestry,
182 Ittinois NatruraAL History Survey BULLETIN
Following passage of the Federal Aid in
Wildlife Restoration Act in 1937, Frison
undertook to arrange a co-operative wild-
life research program with the Illinois
Department of Conservation and the
United States Bureau of Biological Sur-
vey (now the U. S. Bureau of Sport
Fisheries and Wildlife). The first co-
operative project, “Illinois Fur Animal
Resources Survey,” with Louis G. Brown
as leader, was approved on May 23, 1939
(Frison 1940:8-9). In 1940 a Coopera- -
tive Wildlife Restoration Program, em-
bracing interagency co-operation in Fed-
eral Aid, was listed on the staff page on
the section level. Of this program Frison
(1940:8) recorded: ‘General program
planning and supervision of projects deal-
ing with wildlife research have been as-
signed to the Chief and various other
members of the scientific staff of the IIli-
nois Natural History Survey.” In evi-
dence of its success this co-operative ar-
rangement has survived through the years,
and in 1956 the Conservation Advisory
Board (Mann 1956:6) included, in a
statement of policies, provisions for the
development of an adequate game re-
search program “through cooperation
with and support of the Illinois Natural
History Survey Division.”
Thus, by 1940 Frison had stimulated
and obtained support for a wildlife re-
search program which involved the pri-
mary activity of four sections within the
Natural History Survey’s organizational
structure. This compartition of the work
was believed by those who knew Frison
to have grown out of his extreme interest
in wildlife resources and his desire to
give each facet of study his personal
direction.
There was little change in the wildlife
research program while Dr. Leo R. Te-
hon served as Acting Chief, December 10,
1945, through February 28, 1947, follow-
ing Frison’s death on December 9, 1945.
Dr. Harlow B. Mills, who became
Chief on March 1, 1947, proved to have
the same consuming interest in wildlife
research which had marked Frison’s lead-
ership. In August, 1947, the Cooperative
Wildlife Restoration Program was more
properly designated Cooperative Wild-
life Research, and a Section of Migratory
Waterfowl was added to the organiza-
Vol. 27, Art.2 ©
tion. The latter section had been discon- —
tinued by June, 1948.
Dr. Thomas G. Scott was appointed —
the Head of the Section of Game Re- —
search and Management on January 1,
1950. He was the first person to bear —
this title. Soon after that date, arrange-
ments were made for formal co-operation
in wildlife research between the Natural —
History Survey and Southern Illinois
University, where Dr. Willard D. Klim- —
stra was guiding the. program in wildlife
research and education. That part of the —
Survey’s organizational structure,
operative Wildlife Research, which em- —
braced the Federal Aid research, was —
dropped, and the personnel and admin- —
istrative responsibilities of this program
were transferred to the Section of Game
Research and Management in March, —
1950. On September 1, 1954, the Section
of Forestry was abolished, and all of its
wildlife activities and personnel trans- —
ferred to the Section of Game Research ~
and Management. Thus, by 1954 all ©
wildlife research had been assigned to one —
section. The name of the section was —
more appropriately designated the Section —
of Wildlife Research on May 1, 1956. —
The area of research assigned to the sec-
tion was similar to that of its predeces- —
sors: the biology of warm-blooded verte-
brates except that associated with taxo-
In 1956 the ~
extensive activities of the section were —
nomy and_ classification.
divided and were assigned to branches to —
provide for more effective supervision.
The new branches were Nongame Birds, _
Upland Game Birds, Migratory Game ~
Birds, Mammals, Co-operative Wildlife —
Research, and Environmental Research.
As the first century of the Illinois Nat-—
ural History Survey ends, interest in —
wildlife resources of Illinois and other
parts of the United States is greater than
ever before. The number of people en-
gaged in the wildlife management pro- —
fession is at an all-time high and promises
to go higher. Frison’s North Central
States Fish and Game Conference has —
so grown in attendance and extent of in- _
terest that its facilities no longer seem
to meet the needs seen at the outset. As —
a consequence, there is a tendency for —
specialists to draw apart in committees
or “councils.” Some of those who look
Co-
December, 1958 SCOTT:
into the future to a greatly increased hu-
man population and a more _ intensive
land-use program seem to be returning
to Forbes’ ‘‘let’s face the inevitable” phi-
losophy of 1912. They seem willing to
stand by while part of our wildlife her-
itage, the prairie chicken, for example,
goes down the drain. Foreign game birds
are being feverishly investigated and _ re-
leased with the hope of finding species
which will supplement populations of na-
tive game birds being reduced by a chang-
ing habitat. In anticipation of the time
when shootable wild game populations
will no longer meet the demand, there are
the programs for pen-rearing game birds
to be released under the gun. The root-
ing out of osage orange hedges throughout
the state is symbolic of the cancerous-like
growth in activities designed to bring in-
creasing amounts of land into agricul-
tural, residential, or industrial use. Public
realization of the vital importance of
habitat in the management of a wildlife
resource is showing growth; however, the
area of desirable wildlife habitat, espe-
cially that for upland species, is continu-
ing to shrink. Thus, the most perplexing
problem of the wildlife manager in [Ili-
nois today is that of developing and pro-
tecting suitable habitat.
RESEARCH CONTRIBUTIONS
A review of outstanding contributions
made to wildlife biology and conserva-
tion by employees of the Illinois Natural
History Survey and its parent organiza-
tions will aid understanding of work in
these fields during the first 100 years. A
few publications by non-Survey personnel
are cited to provide perspective or to
recognize Survey publications by workers
who were not employed by the Survey.
Birds
Contributions on the biology and con-
servation of birds may be conveniently
grouped into three classes: those for non-
game, those for upland game, and those
for migratory game birds.
Nongame Birds.—Of the meadow-
lark, Forbes (18815:234—-5) wrote:
He is first cousin to the Indian, the prairie-
wolf and the badger, but with a better knack
WILDLIFE RESEARCH 183
than they at adapting himself to the new life
of civilization. He is a perfect reflection of
his most constant surroundings—with a
bosom of prairie butter-cups, a back like the
dead grass of autumn, and a song that harmo-
nizes well with the whistling of prairie winds.
This colorful description reveals some-
thing of Forbes’ deep feeling for birds.
Sentiment, however, is not evident in
his systematic and painstakingly conserva-
tive evaluations of the place of birds in
an economic scheme of things.
Forbes’ research on the food of birds
constituted a milestone in ornithological
history. ““No part of the recent work of
the Laboratory has excited a wider inter-
est than that relating to the food of
birds’ (Forbes 1880f:7). This work
established Forbes among contemporary
ornithologists as the ranking authority
on the insect food of birds. Dr. Elliott
Coues (1883:105) believed him to be
“Our best authority upon the insect food
of birds...” Drs. Clarence M. Weed
and Ned Dearborn (1903:19-20) con-
sidered Forbes’ publications on the food
of birds to be ‘“‘classic papers” and “‘the
basis for the modern development of
economic ornithology.”
The findings of Forbes’ studies of the
food of birds appeared in a number of
papers. ‘The most substantial contribu-
tions, however, were brought together in
two papers (Forbes 1880d, 1883a). The
first dealt with the food of certain birds
in the families Mimidae and Turdidae.
The second reported observations on the
regulative action of birds feeding on an
excessively high population of canker-
worms and vine leaf chafers. The latter
paper, “The Regulative Action of Birds
Upon Insect Oscillations,” was approved
by Indiana University in fulfillment of
Forbes’ thesis requirements for the Ph.D.
degree granted in 1884 (letter of May 2,
1952, from E. Lingle Craig, Reference
Librarian, Indiana University, to Mar-
guerite Simmons, Librarian, Illinois Nat-
ural History Survey). Of lesser im-
portance were notes on the food of the
meadowlark (Forbes 18814), the English
sparrow (Forbes 1881c), and the kinglets
(Forbes 1883d).
The scope of these investigations may
be seen in the following report (Forbes
1882a: 5-6) :
184 Inuinors NaruraAt History Survey BULLETIN
The collection designed to illustrate the food
of birds has been more than doubled in the
last two years, and now numbers over six
thousand stomachs, representing about two
hundred species. Eight hundred and eighty of
these have now been exhaustively studied, ...
Unfortunately, the analyses were ap-
parently discontinued at this point, for
there were no more publications on the
food of birds, and the annual reports of
the State Laboratory of Natural History
indicate that nothing further on this sub-
ject was done.
Forbes’ evaluations of his findings on
the food of birds indicated awareness of
the need for giving special consideration
to the high mobility of birds, food prefer-
ences, density effects, ability to diversify
diet, and the importance of seasons, geo-
graphic location, and specific ecological
circumstances. Forbes (1880e:122-3) de-
scribed what appears to have been a new
method of evaluating proportions of food
in the stomachs and crops of birds, a
technique which is used yet today. He
(Forbes 1881a:107) also showed himself
to be aware of the importance of sample
size and made crude tests for significance
by comparing the results of analyses of
small samples with those of larger
samples to determine whether there were
important departures in the pattern of
the diet.
Because Forbes believed that the num-
bers and kinds of birds in specific habitat
categories needed to be known before
their economic importance could be evalu-
ated, he encouraged studies based on sys-
tematic censuses, which were carried out
in 1906, 1907, 1908, and 1909. These
studies are classics in American ornithol-
ogy and introduce a new censusing tech-
nique for birds. | believe them to be the
first extensive statistical analyses of bird
populations in this country. Although the
results of these surveys are presented in
six papers, two of them contain most of
the data (Forbes & Gross 1922, 1923).
Unfortunately, a final paper in which it
was hoped to present all of the findings
for each species was never published.
Plans for this paper are described (Forbes
& Gross 1923:397) as follows:
It has been our general plan to work at first
with broad strokes of the full brush, refining
upon our neutral background by degrees and
ending, as we hope to do in a paper follow-
3Z
Vol. 27, Art. 2 |
ing the present one, with the final details for —
each species taken up separately and followed —
all over the state and around the year.
Forbes’ experience with plankton sur-
veys guided him in the development of —
the census technique devised specifically —
for the bird surveys (Forbes & Gross
1921:1). Forbes believed that two men
walking abreast could identify and count
all of the birds flushed by them or cross-
ing their track on a strip 150 feet wide
in relatively open country but 60 feet —
wide in heavier cover, such as orchards,
open woods, and patches of close shrub-
bery. This census technique was pictured
(Forbes & Gross 1921:1) as a
huge net a hundred and fifty feet wide,
drawn in straight lines across every kind of
crop or other surface vegetation, by which
all the birds found there should be caught
and held unt:! they had been identified and
counted.
Results were obtained by application of
this census technique during the summers
of 1907 and 1909 (Forbes & Gross
1922:189, 199); the census indicated
an average of 852 birds per square mile
for the state as a whole. The numbers of
birds per square mile showed a striking
increase of 5+ per cent from the 1907 fig-
ure to that of 1909. Orchards were found
to have the greatest numbers of birds per
square mile, 3,943; yards and gardens
were a close second with 3,418. The state-
wide number of birds per square mile in
winter was estimated from data collected
in 1906 and 1907 to have been 520
(Forbes & Gross 1923:398).
Dr. Frank Smith (1930) prepared a
thorough and useful paper dealing with a
chronology of the spring migration of 221
species of birds through Urbana from
1903 throuzh 1922. The objective of the
study was to determine whether there was
a correlation between migration flights of
spring migrants and certain kinds of
weather. Smith (1930:112) concluded:
A careful study of the weather maps during
the time when records were being made re-
vealed that the greatest migratory activity
in spring occurred at times when the weather
maps showed an area of low barometric
pressure approaching from the west, with the
south winds and rising temperatures which
normally accompany such movements.
The monograph by Dr. Alfred O.
Gross (1921) on the dickcissel must be
December, 1958 Scott: WILDLIFE RESEARCH 185
classified as one of the outstanding early
studies of its kind. I was especially im-
pressed by his statistical evaluation of the
abundance of the bird in relationship to
Ornithologists in winter equipment ready to
State Laboratory of Natural History, about 1906.
is Howard A. Ray.
habitat categories. He found that hay-
fields constituted preferred habitat; with-
in this classification, clover and alfalfa
were preferred to other kinds of hayfields
set out on a collecting expedition for the Illinois
At the right is Alfred O. Gross, and with him
186 ILtLinois NATURAL
available at the time. Perhaps it is also
appropriate to mention the paper by W.
E. Loucks (1894) on the prothonotary
warbler. While the paper is unfortu-
nately more subjective than objective, it
constitutes a colorful record of the find-
ings of a talented observer.
The participation of the Natural His-
tory Survey staff in the effort to obtain
legal protection for all hawks and owls in
Illinois merits attention. At the urging
of Dr. David H. Thompson, Director
Ralph Bradford of the Illinois Depart-
ment of Conservation sought and obtained
legislation, effective July 1, 1929, to pro-
tect all hawks and owls except the great
horned owl, the goshawk, sharp-shinned
hawk, Cooper’s hawk, duck hawk, and
pigeon hawk.
Members of the Natural History Sur-
vey staff continued to advocate ig ew
of hawks and owls, and, effective July 1,
1941, protection was obtained for all but
the great horned owl. This condition pre-
vailed until July 1, 1947, when, for some
unexplained reason, the Cooper’s and
sharp-shinned hawks were removed from
the protected list. In 1956 and 1957 a
new effort, spearheaded by Elton Fawks,
representing the Illinois Audubon Soci-
ety, was made to obtain protection for all
hawks and owls. I presented a paper at
the annual meeting of the Natural Re-
sources Council of Illinois on October 20,
1956; this paper has been credited with
having much to do with winning the sup-
port of the Council and member clubs for
the needed legislation (Fawks 1957:1).
I read a second paper at the annual meet-
ing of the Illinois Audubon Society in
Rockford on May 18, 1957, at the time
the bill was before the legislature (Bay-
less 1957:3), and I made an appeal for
further support in the official publication
of the Illinois Federation of Sportsmen’s
Clubs (Scott 1957). Dr. Richard R.
Graber assisted this effort by analyzing
data on hawk and owl numbers reported
in the Christmas counts of the Illinois
Audubon Society for the past 50 years
and by demonstrating that some species
had declined in numbers and that there
was no evidence of need for measures de-
signed to reduce hawk and owl popula-
tions. The bill proposed for the protec-
tion of hawks and owls, House Bill No.
Hisrory
Survey BULLETIN Vol. 27, Art. 2
1063, included protection also for the
crow, blue jay, cowbird, and grackle by
the time it had passed the General As-
sembly, June 27, 1957, and was signed
into law by Governor William G. Strat-
ton, July 8, 1957 (Illinois General As-
sembly 1957:1937-8). The bill pro-
vided for amending Section 21 of the
Game Code to define all hawks and owls
as protected species but, as a consequence
of an oversight, Section 36 of the Code
was not amended to include the Cooper’s
hawk, the sharp-shinned hawk, and the
great horned owl among the hawks and
owls which were unlawful to have in pos-
session at any time.
The Prairie Chicken.—lIf the IIli-
nois farmer of the 1860’s had taken time
from his backbreaking work to sit down
and figure out the cause of the enormous
populations of prairie chickens which he
alternately cursed and blessed, perhaps he
would have seen that he had just com-
pleted a gigantic habitat development
project for upland game birds. He had
extended the range of the chicken by clear-
ing the timberland, and he had provided
thousands of food patches by establishing
grainfields.
From these high populations, the prai-
rie chickens declined in numbers with the
gradual increase in grain farming and the
accompanying reduction of grassland.
The hunting season on prairie chickens
was closed in 1903 and was not opened
again until 1911. The relaxation of hunt-
ing regulations at this time undoubtedly
followed an increase in the population,
probably associated with “The Indiana
‘Comeback’ of 1912” (Leopold 1931:
172). Contemporary data for Illinois
had apparently not been called to Leo-
pold’s attention because Forbes (1912b:
47-8), reported that
prairie-hens—thanks to our protective laws—
are now to be seen in at least seventy-four
counties, so abundantly in some that farmers
are beginning to protest against their further
increase because of the amount of grain
which they devour.
The records on which this statement is
based remain in the files of the Illinois
Natural History Survey. Re-examination
of them brings out the conservativeness
of Forbes, for they indicate that the re-
porting observers had found a few prairie
December, 1958
chickens in all of Illinois’ 102 counties
except 10 (Yeatter 1957:8). Despite an
exaggerated confidence in protective regu-
lations, Forbes (1912b:48) recognized
the basic environmental factor which was
limiting the prairie chicken population be-
cause he advised that:
The very country in which it was formerly
most numerous—that is, the open prairie—
is now least favorable to it because of the
agricultural operations, which disturb and
destroy it during its breeding season.
When it again became evident that the
prairie chicken population was endan-
gered, Director Bradford of the Depart-
ment of Conservation, at the urging of
Dr. Thompson of the Natural History
Survey, obtained legislation, effective July
1, 1933, to prohibit the taking of the
prairie chicken at any time. No open sea-
son on this bird has been permitted since
that date.
It seems fitting that, with the upsurge
of interest in wildlife conservation in the
1930’s, one of the first comprehensive
studies of a game species to be undertaken
in Illinois was concerned with the prairie
chicken. The valuable monograph (Yeat-
ter 1943) resulting from this study in-
cludes data on early distribution, range,
life history, populations, mortality causes,
food habits, and management. I believe
that this publication was the first to direct
attention to the importance of grass-seed
farming in the management of prairie
chickens. Yeatter (1943:409) advised
that areas harboring a few prairie chick-
ens
might be converted into good chicken range
by leasing, and converting to refuges for a
term of years, 25 per cent of the total land
in the form of 20-acre, 40-acre or larger
tracts of the poorer farm soil throughout each
township.
In a later publication Yeatter (1957:8)
revised his recommendation on grassland
refuges to a minimum of 40 acres in each
square mile of farm land.
When unusually large numbers of
young prairie chickens were found dead
on a study area in Jasper County in 1935
and 1936, an investigation of parasites as
a possible cause of these deaths was un-
dertaken (Leigh 1940:186). Tapeworms
were found in 10 of 14 partly grown birds
and in not one of 14 adults which were
Scott: WILDLIFE RESEARCH 187
collected in Jasper and Richland counties
in the summers of 1936 and 1937.
Because cestodes of a previously undescribed
species of Raillietina occurred in 10 [ac-
tually 9] of 14 young birds and in 4 cases
were sO numerous or so large as to occlude
the lumen of the greater part of the small
intestine, they should not be overlooked as
a factor in prairie chicken mortality (Leigh
1940:188-9).
Shelford & Yeatter (1955) interpreted
year-to-year population fluctuations of
male prairie chickens during a period of
18 years on the study area near Hunt in
Jasper County, Illinois, in relation to
weather and climate. Field observations
indicated that the period of the late stages
of development of the reproductive cells
during April, the period of egg-hatching
in June, and the period when young prai-
rie chickens were 4 to 8 weeks old were
critical times in the reproductive cycle of
prairie chickens. Many trials in which
various weather records were used showed
that the population level tended to re-
spond to only two weather combinations:
(1) rainfall and sunshine in April and
(2) rainfall and temperature in June.
Reproduction was most successful in sea-
sons when April rainfall averaged 2-5
inches and when 48-64 per cent of the
possible hours of sunshine were experi-
enced. As the amounts of rainfall and
sunshine varied from these optimum lim-
its, reproductive success became progres-
sively lower.
Thus, the prairie chicken in Illinois has
passed from the enormous populations of
Civil War times to small, scattered colo-
nies, in only 24 counties in 1957 (Yeatter
1957). It seems evident that the prairie
chicken will soon become something of
the past in Illinois unless a positive pro-
gram of management such as that being
proposed at the present time saves them.
The Bobwhite Quail.—vTo the up-
land bird hunter of Illinois, events which
established the present boundaries of IIli-
nois proved inadvertently provident, for
they led to the inclusion of excellent quail
range over the southern one-third of the
state as well as what was to become fairly
good pheasant range in the northern one-
third.
Illinois has the distinction of being the
locale of the first systematic and extensive
188
census of quail populations. These cen-
suses were carried out during the period
1906-1909 by a strip-census technique
(Forbes & Gross 1921, 1922, 1923). The
increase in the density of quail popula-
tions from north to south in Illinois was
just as clearly marked in the findings of
Forbes and Gross as it is today. Cen-
suses during the summers of 1907 and
1909 revealed quail populations of 21
birds on 7,966.5 acres or 1 bird per 379.4
acres in northern Illinois, 53 birds on
5,823.9 acres or 1 bird per 109.9 acres in
central Illinois, and 241 birds on 5,527.2
acres or | bird per 22.9 acres in southern
Illinois (Forbes & Gross 1922:191, 197).
A similar distribution of quail popula-
tion densities was evident in the winter
counts made during the period November
23, 1906, through February 21, 1907,
when 180 quail were counted on 1,422.4
acres or | bird per 7.9 acres in southern
Illinois and 54 on 4,956.0 acres or 1 bird
per 91.8 acres in central and northern
Illinois combined (Forbes & Gross 1923:
398, 400). The data for the counts made
during the summers of 1907 and 1909 in-
dicated an increase in quail populations
for the state as a whole; 91 quail were
counted on 7,693.6 acres, 1 bird per 84.5
acres, in 1907 and 224 birds on 11,624.1
acres, 1 bird per 51.9 acres, in 1909
(Forbes & Gross 1922:191).
The densities of quail populations were
recorded by general habitat category. In
a special study, August 19 to September
15, 1908, in which orchards in the vicin-
ity of Centralia and Olney received spe-
cial attention, 774.5 acres of orchard and
594.5 acres in other habitat categories
were censused ; 356 quail, 1 per 2.2 acres,
were counted in the orchards and 32, 1
per 18.6 acres, outside the orchard area
(Forbes & Gross 1921:5, 7). The im-
portance of undisturbed grassland to the
management of quail was suggested by
Forbes & Gross (1921:3) in their consid-
eration of reasons for the high densities
of quail in orchards when they concluded:
“Evidently it is not the trees that attract
it, but the cover afforded by an undis-
turbed growth of grass and weeds be-
tween the rows.”
Following these early censuses, there
Was a pause in the attention given quail
by Natural History Survey researchers.
ILtinois NATURAL History SURVEY BULLETIN
Vol. 27, Art. 2
The species did not become the subject of
further study until the hunting season of
1936, when 141 quail were collected in
an investigation of helminth parasites by
Leigh (1940:186, 190), who concluded
“that the quail of Illinois are not so heav-
ily infested with the diversity of helminth
parasites as are the quail of the southeast-
ern states.’ In the summer of 1938 a
brief investigation of quail productivity in
Calhoun County was carried out by Bell-
rose (1940:10), who pointed out the im-
portance of undisturbed grassland and
concluded that the possibilities for provid-
ing suitable nesting sites were greatest in
apple orchards.
In 1948 and 1949 the hatchability of
the eggs of the bobwhite was compared
with that of the eggs of pheasants after
experimental exposure to temperatures of
62, 73, 78, 83, and 88 degrees F. for a
period of 7 days to simulate preincubation
exposure (Yeatter 1950:529). Yeatter
(1950:530) concluded that “No signifi-
cant reduction of hatchability of the bob-
white eggs by high temperatures was evi-
dent.”
Bobwhite quail were investigated from
1948 to 1954 on the Crab Orchard Na-
tional Wildlife Refuge, in Williamson
County, to determine what types of cover
importantly influenced the abundance of
quail (W. R. Hanson & R. J. Miller un-
published MS). Quail abundance was
significantly correlated with the amount
of “edge” between cultivated fields and
brushy pastures. Twenty-five linear miles
of multiflora rose hedges, planted on an
area of about 5.5 square miles, failed to
increase the numbers of quail.
A most important step was made in the
direction of a thoroughgoing investigation
of the biology of the bobwhite quail in
Illinois by the signing, on October 3,
1950, of a memorandum of understanding
providing for co-operation between the
Natural History Survey and Southern
Illinois University. The observations and
impressions (Scott & Klimstra 1954) ob-
tained during a trip to quail management
areas in southeastern United States for
the purpose of co-ordinating this co-oper-
ative program of research in Illinois with
work elsewhere are believed noteworthy
and cover the following subjects: hunting,
management of habitat, and populations.
i
December, 1958 ScorT:
The co-operative research has involved
nearly all phases of quail biology and an
experimental habitat management pro-
gram. Among the important contributions
are two studies, one on the diet of quail
(E. J. Larimer unpublished MS) and the
other on quail populations on an unman-
aged area. he second study has empha-
sized once again the great importance of
undisturbed grassland to quail productiv-
ity and provided evidence of the amount
and distribution of undisturbed grassland
required to insure high quail productivity.
The quail investigations have received
outside financial assistance from Max
McGraw, A. E. Staley, the North Ameri-
can Wildlife Foundation, and the United
Electric Coal Company; the coal com-
pany also has made available extensive
landholdings for experiments with habitat
management.
The Ring-Necked Pheasant.—Al-
though the attempt to establish pheasants
in Illinois had gotten under way in the
1890’s, this state’s biological research-
ers were apparently unimpressed with it
as a subject for investigation. In a dis-
cussion of the animal resources of the
state, Forbes (1912b:48) advised that he
had not had time to appraise efforts to im-
prove “the composition of our fauna by
the introduction of exotic species.” Little
or no attention was given pheasants until
Leigh (1940:190) made his limited sur-
vey of the parasites of pheasants collected
during the hunting season in 1936. Dur-
ing the summer of 1938 Bellrose (1940)
made nesting studies and population esti-
mates of pheasants in the southern part of
Calhoun County, which is outside the
recognized range of pheasants in Illinois.
His observations (Bellrose 1940:9) ap-
peared to indicate that this population
had been maintained by repeated releases.
Intensive investigations of the ring-
necked pheasant did not get under way
until April 1, 1946, when the Illinois De-
partment of Conservation, the U. S. Fish
and Wildlife Service (now the U. S. Bu-
reau of Sport Fisheries and Wildlife),
and the Illinois Natural History Survey
entered into a co-operative project with
Federal Aid funds. Dr. William B. Rob-
ertson (1958) described the results of
this co-operative research from inception
to December 31, 1951, together with an
WILDLIFE RESEARCH 189
account of the early history of pheasants
in Illinois and an analysis of the factors
limiting the pheasant range.
His report constitutes the first com-
prehensive account of pheasant research
in Illinois. It is a valuable historical rec-
ord of early introductions of pheasants
and the development of hunting regula-
tions. Curves based on an annual aver-
age of over 300 dates of the hatching of
eggs in nests were constructed and ana-
lyzed for effects of photoperiod, weather,
and farming operations. Observations
made on the breeding behavior of marked
birds released in Kendall County are be-
lieved to be especially enlightening. Of
particular note to students of populations
and behavior was the observation that
adult hens tended to become associated
in the harems earlier than did juvenile
hens. One of the earliest attempts to
eliminate bias from evaluation of the
worth of artificial stocking is reported
upon in the paper. Robertson (1958:
129) concluded “that 35 to 50 per cent
of the cock pheasants in summer releases
in Illinois were bagged in the succeeding
hunting season. ‘The recovery rate for
spring-released adult cocks, estimated by
similar methods, was only 6.1 per cent.”
In Livingston County a release of 1,000
adult hens in September of 1948 resulted
in a survival of about 50 per cent to May,
1949; released hens made up one-third of
the hens on the area at the latter date. It
was found that about 33 per cent of the
broods seen the following summer were
accompanied by released adult hens. In
Kendall County the effect of a release of
500 adult hens in August and 1,000 ju-
venile hens in November and December
of 1949 was evident when it was seen that
25 per cent of the broods in 1950 were
accompanied by released hens.
There has been much speculation as to
the reason pheasants have failed to be-
come established in southern United
States. During brood studies beginning
in 1937, Yeatter (1950:529) observed
that the hatchability of pheasant eggs fre-
quently declined in late spring in east-
central Illinois, which is on the southern
edge of the pheasant range. This observa-
tion suggested that high environmental
temperatures at the time of egg-laying con-
stituted a critical limiting factor. In 1948
190 Ittinois NATURAL History SuRvVEY BULLETIN
and 1949 Yeatter (1950:529) compared
the effect of temperature on paired lots of
pheasant and quail eggs during a 7-day
preincubation period and stated “that the
hatchability of pheasant eggs was reduced
by heat exposures, the reduction increas-
ing with the higher temperatures.” It
was concluded that this vulnerability of
pheasant eggs to high air temperatures
constituted an important barrier to the
southern distribution of pheasants, and it
was suggested that pheasants in the south-
ern Pacific Coast and Rocky Mountain
regions might be more tolerant of higher
temperatures. Recent experiments by
Yeatter lend strong support for this sur-
mise (Yeatter unpublished MS).
At the present time, the Illinois De-
partment of Conservation, the Illinois
Natural History Survey, and the U. S.
Bureau of Sport Fisheries and Wildlife
are co-operating in a comprehensive and
intensive investigation of the ring-necked
pheasant. This research is being carried
on by Dr. William R. Hanson, Dr. Fred-
erick Greeley, Jack A. Ellis, and Ronald
F. Labisky and involves study of range-
limiting factors, the biology of pheasants
within the established range, and experi-
ments with the establishment of self-
maintaining populations outside the ex-
isting range.
The Canada Goose.—Canada geese
wintering on the islands and bars in the
Mississippi River from Chester, Illinois,
southward to Cairo must have found the
fight for survival during the early part
of the twentieth century severe indeed.
The conservationists who, with the ob-
jective of providing for pole-and-line fish-
ing, arranged for the purchase of Horse-
shoe Lake, an ancient oxbow of the Mis-
sissippi River in Alexander County, by
the Illinois Department of Conservation
in 1927 were unaware of the part they
would play in protecting this goose popu-
lation and setting the stage for its future
growth. About 1,900 Canada geese win-
tered at Horseshoe Lake, now famous as
the Horseshoe Lake Game Refuge, dur-
ing the first year. During the winter of
1957-58, about 225,000 Canada geese
wintered in southern Illinois; these geese
constitute a resource which has been esti-
mated to contribute about $1,500,000 an-
nually to the economy of southern []linois.
Vol. 27, Art. 2
The refuge was soon surrounded by
commercial shooting clubs, and a problem
which attracted national interest was
created. Leopold (1931:206) wrote:
“The question of whether public refuges
should be surrounded by public shooting
grounds is frequently debated. Horse-
shoe Lake in Alexander County, Illinois,
is a good place to study the question.”
Nevertheless, it was not until 1939, when
about 40,000 (the same number estimated
to have been killed in southern I[Ilinois in
1957) geese were wintering at the refuge,
that the annual kill and the need for
knowledge on which to base intelligent
control became alarming enough to at-
tract researchers.
In 1940 Arthur S. Hawkins initiated
the Illinois Natural History Survey’s
long-time research program on Canada
geese (Hanson & Smith 1950:70), and
in 1941 geese were banded in the area
for the first time by Hawkins and John
M. Anderson. ‘The initial effort was
necessarily directed toward the develop-
ment of efficient trapping and handling
methods (Hanson 1949a), and colored
bands were tested on geese (Balham &
Elder 1953) for the first time.
The massing of so large a portion of
the Canada geese of the flyway at Horse-
shoe Lake created a unique opportunity
for population research. Practical meth-
ods for aging geese were worked out for
the first time (Elder 1946; Hanson
1949b, 1953a), and these methods, which
were used for measuring the composition
of the population, formed the basis for
all subsequent investigations. Elder’s
(1946:94-8) analysis of the weight of
Canada geese by sex and age constituted
the first analysis of its kind for geese.
Hanson (1949) developed techniques
for placing Canada geese in three age
categories (juvenile, yearling, and adult),
thus making possible a considerable ad-
vancement in the understanding of popu-
lation mechanics in these birds.
A definitive investigation of the biol-
ogy of the Canada goose constitutes the
long-range objective of the research on
this species. Early findings were reported
in a 144-page article (Hanson & Smith
1950). In this article the four flyway
populations of Canada geese breeding in
the general area of Hudson Bay were
December, 1958
revealed for the first time. “The breed-
ing range, migration routes, wintering
grounds, and populations were discussed
for each flyway population. Later, the
South Atlantic Flyway population was
treated in greater detail (Hanson & Grif-
fith 1952). Observations on the relation
of hunting losses to the age structure of
the population wintering at the Horse-
shoe Lake Game Refuge proved especially
useful. The heavy kills of immature
geese in the first half of the 1940’s not
only altered the age composition of the
flock but reduced the average longevity of
these geese as shown by life survival
indices, the first constructed for a species
of waterfowl (Hanson & Smith 1950:
172-88). A recent 3-year study of the
kills of Canada geese by the natives of
the Hudson-James Bay region has estab-
lished the location and size of these
hunting losses with exactness (Hanson &
Currie 1957).
The Canada geese on the Horseshoe
Lake Game Refuge provide a unique op-
portunity for study of behavior. The
adult males of the largest families usually
dominate males leading smaller families,
and the social rank of the adult female
is determined by that of her mate (Han-
son 19535). The conception ‘that the
small goose flock is usually a family and
that larger flocks are frequently multiples
of families rather than mere aggregations
of individuals . . .” also became apparent
in observations made at the Horseshoe
Lake Game Refuge (Elder & Elder
1949:139).
Diseases and parasites of Canada geese
have been investigated in anticipation of
epizootics among geese crowding into
winter refuges. Blood protozoa (Levine
& Hanson 1953) and microfilaria (Han-
son, Levine, & Kantor 1956; Hanson
1956) have been surveyed. The preva-
lence of helminths in relation to age and
the incidence of Leucocytozoon infection
in immature geese are currently under
study. Dr. Norman D. Levine (1953)
made a valuable review of the literature
on coccidia in the avian orders Galli-
formes, Anseriformes, and Charadri-
iformes. Coccidial infection was initially
investigated in the flock at the Horseshoe
Lake Game Refuge by Levine (1952),
and the coccidia of North American wild
Scott: WILDLIFE RESEARCH 191
geese and swans were subsequently con-
sidered by Hanson, Levine, & Ivens
(1957). Host specificity of some species
of coccidia was shown, and certain coc-
cidia seemed restricted to one flyway popu-
lation. Thus, coccidia appeared to offer
promise as biological tracers for confirm-
ing the distribution of flyway populations
indicated earlier by band _ recoveries
(Hanson & Smith 1950:74-9).
Ducks.—The early settler found mul-
titudes of ducks in Illinois, not only
along major streams, but also on the
prairie sloughs. ‘The vast numbers of
ducks migrating through the bottomlands
of the Illinois River valley made this
valley a famous shooting ground as far
back as the 1880’s. Indeed, in 1886, a
group of businessmen from the Peoria
area founded the Duck Island Preserve,
probably the first hunting club in the
state.
Prior to 1900 the Illinois River and
its connecting waters were in a near
pristine condition. Sloughs and lakes con-
tained an abundance of aquatic vegeta-
tion (Kofoid 1903), which provided food
for ducks; other food was furnished by
pecan nuts and pin oak acorns which be-
came available when high water flooded
the low-lying, timbered bottoms. In
January of 1900 the Chicago Sanitary
and Ship Canal was opened, greatly in-
creasing earlier diversion of water from
Lake Michigan (Mulvihill & Cornish
1930:53). This increased diversion re-
sulted in water levels which were high
enough to destroy extensive tracts of bot-
tomland timber, including most of the
pecans and pin oaks, in the Illinois River
valley.
During the early 1900’s not only were
the tracts of mast-producing trees, so im-
portant as sources of food for mallards,
lost to the ducks, but drainage destroyed
many other important feeding grounds.
Between 1900 and 1922, almost 200,000
of 400,000 acres in the flood plain of the
Illinois River valley were leveed and
drained (Mulvihill & Cornish 1930).
The number of ducks in the lower flood
plain area and shooting success declined
when the mast-producing trees were lost.
Then the practice of feeding waterfowl
was begun at some duck hunting clubs in
the early 1900’s, was prohibited by state
192 IL~tinois NATURAL History SURVEY BULLETIN
law from 1909 to 1911, became a wide-
spread practice in the 1920’s, and was
prohibited by federal regulation in 1935
(Bellrose 1944:333).
Finally, in recognition of the import-
ance of waterfowl problems in Illinois,
the Natural History Survey employed
Arthur S. Hawkins and Frank C. Bell-
rose to initiate a waterfowl research pro-
gram in 1938. Up to that time, the study
Vol. 27, Art. 2
fect of baiting and live decoys on water-
fowl and “estimated that 6,000,000
bushels of corn were fed by Illinois clubs
during the 1933 season’ (Bellrose 1944:
365).
About 1938 initial attention was given
to the wood duck, and in 1939 the first
successful nesting box of rough-cut lum-
ber was developed for this waterfowl spe-
cies (Bellrose 1953a). By experimenta-
ee
Wildlife technicians preparing to fluoroscope a mallard drake at the Illinois Natural His-
tory Survey field laboratory near Havana. The fluoroscope has facilitated studies involving
crippling by hunters and lead poisoning.
of waterfowl had received little attention
in Illinois. In 1922, at duck hunting
clubs near the mouth of the Sangamon
River, Dr. Frederick C. Lincoln (1924)
of the U. S. Bureau of Biological Survey
(now the U.S. Bureau of Sport Fisheries
and Wildlife) made the first large-scale
bandings of ducks in North America.
Francis M. Uhler of the same agency
examined the food contents of duck giz-
zards collected at the Duck Island Pre-
serve in 1933 (Uhler unpublished re-
port). Also, Uhler investigated the ef-
tion, a nest box entrance with a 4-inch
horizontal measurement and a 3-inch
vertical one was evolved in 1942 for
the purpose of excluding raccoons which
were preying upon the hens and their eggs.
In 1950, a cylindrical, galvanized metal
house was developed to exclude fox squir-
rels, as well as raccoons, as predators on
wood duck eggs.
Because diversion of Lake Michigan
water, drainage, and sediment decreased
the duck foods in the Illinois River val-
ley, several of the early investigations
December, 1958 ScoTrT:
dealt with duck food plants. A study of
the ecology of aquatic and marsh plants
revealed the relationships of fluctuating
water levels and turbidity to plant
growth (Bellrose 1941). As a result of
this study, two techniques for production
of duck foods were recommended: (1)
dewatering certain areas to encourage
growth of moist-soil plants on exposed
mud flats and (2) stabilizing water levels
at depths of 2 to 3 feet to promote growth
of aquatic plants.
A study of the relative value of various
plants as duck foods (Bellrose & Ander-
son 1943:432-3) showed that moist-soil
plants, such as rice cut-grass, millets,
smartweeds, and nutgrasses, were much
more valuable as duck foods than such
aquatic and marsh plants as the pond-
weeds, coontail, duck potato, and bur-reed.
This study is believed to be the first in
which the food habits of waterfowl were
related to food availability. Later, a
study by Low & Bellrose (1944:21) re-
vealed that, among 28 waterfowl food
plants, 6 of the 7 heaviest seed producers
were emergent or moist-soil plants.
Harry G. Anderson (unpublished MS)
made a little known but substantial con-
tribution to knowledge of the diet of
ducks in Illinois when he analyzed and
reported upon the contents of 4,977 giz-
zards of ducks, representing 17 species,
taken during the hunting seasons in 1938,
1939, and 1940.
In a sense, Illinois is at the bottleneck
of the Mississippi Flyway, the flyway
with the largest population of ducks in
North America. The resulting constric-
tion of duck populations streaming into
Illinois has provided a remarkably fine
opportunity for study of flyway popula-
tions. A comprehensive investigation of
sex and age among ducks, covering 1939
through 1954, has been completed (Bell-
rose, Hawkins, Low, & Scott unpublished
MS). From 1938 through 1958, periodic
censuses have been taken of waterfowl
populations in the Illinois River valley
during fall, winter, and spring. In 1946
the census route was expanded to include
the Mississippi River valley between
Rock Island and Alton. ‘These censuses
have provided information on the effect
of weather, water levels, food, and
refuges upon waterfowl populations.
WILDLIFE RESEARCH 193
A 5-year investigation of duck popula-
tions and kill by hunters revealed that
“altering the length of the season is one
of the most expedient ways to regulate
the duck kill” (Bellrose 1944:371). The
most desirable dates for waterfowl hunt-
ing seasons of various lengths in Illinois
were determined (Bellrose 1944:371):
For a 30-day season, November 1-30; for a
45-day season, October 22—December 5; for
a 60-day season, October 10-—December 8;
for a 70-day season, October 1-December 9;
for an 80-day season, September 26—December
14; for a 100-day season, September 20-
December 28.
A study of flyway refuges in Illinois
(Bellrose 1954:169) led to the conclu-
sion that they were of value both to
waterfowl and to hunters. Flyway
refuges permitted waterfowl to rest along
the flyway during the hunting season and
placed more food within their reach,
thereby conserving food resources on the
wintering grounds. Waterfowl concen-
trating on the refuges fed in fields and
marshes within their daily cruising range.
Thus, the refuges provided for holding
local concentrations of ducks which could
be shot when they flew out to feed.
One of the most impressive duck flights
in a decade swept through Illinois on
November 2, 1955 (Bellrose 1957). It
was determined that most of the birds in
the flight left Canada on November 1
and moved so rapidly that some reached
the Gulf of Mexico by the morning of
November 3. This mass migration of
waterfowl was evaluated by Bellrose
(1957:24) as follows:
Low pressure areas in Canada resulted in a
southward flow of a mass of Continental
Arctic air. The low temperatures resulting
from Continental Arctic air triggered the
flight from the Great Plains of Canada and
the United States.
Over 75,000 ducks, largely mallards,
have been banded by Natural History
Survey investigators at four widely sepa-
rated localities in the state. Recoveries
from some of the bandings were used in
calculating the annual mortality of the
mallard, black duck, and _ blue-winged
teal (Bellrose & Chase 1950). Of the
three species, the mallard proved to have
the lowest mortality rate, and_ this
“amounted to 55 out of 100 birds the
194 Ittinois NaturAL History SurvEY BULLETIN
first year, or year of banding, 20 the sec-
ond year, 11 the third year, and 6 the
fourth year” (Bellrose & Chase 1950:
25). The banding data have also been
used to delineate the migration routes of
ducks passing through Illinois.
As part of an effort to evaluate losses
from crippling by hunters, several thou-
sand ducks were trapped and fluoroscoped
for shot pellets and broken bones. Among
apparently healthy mallards, 36.4 per .
cent of the adult drakes, 18.0 per cent
of the juvenile drakes, and 21.4 per
cent of the hens were carrying one or
more shot pellets imbedded in flesh or
internal organs (Bellrose 1953b:344).
“Of the ducks . . . knocked down by
hunters, as reported from various sections
of the United States, 22.5 per cent were
not retrieved’ (Bellrose 19535:357).
A spectacular die-off of mallard ducks near
Grafton in January, 1947, prompted a joint
investigation by the Natural History Survey
and the United States Fish and Wildlife
Service [now U. S. Bureau of Sport Fisheries
and Wildlife]. A still greater die-off in the
same area a year later attracted the attention
of officials of the Western Cartridge Com-
pany of East Alton. As an outgrowth of
the situation, a co-operative investigation of
lead poisoning in waterfowl was begun in
July, 1948, by the Illinois Natural History
Survey, the Western Cartridge Company,
which is a Division of the Olin Industries,
Inc. [now Olin Mathieson Chemical Corpora-
tion], and the University of Illinois (Jordan
& Bellrose 1951:3-4).
Although Lubaloy shot and _ several
lead alloys were tested as substitutes for
commercial lead shot, none showed prom-
ise in alleviating lead poisoning in water-
fowl (Jordan & Bellrose 1950:167-8). It
was estimated by Bellrose (1959) that
each year approximately 4 per cent of the
mallards of the Mississippi Flyway die
from lead poisoning and that an addi-
tional 1 per cent are afflicted with lead
poisoning but are bagged by hunters. Al-
though several other species of ducks in-
gested larger numbers of shot per bird
than did the mallard, the mallard suffered
the highest rate of loss. Mortality from
lead poisoning proved to be greater among
ducks of the Mississippi Flyway than
among those of other flyways. The use
of iron shot as a substitute for lead shot
was suggested as a possible means of con-
tending with the lead poisoning problem
Vol. 27, Art. 2
in the event drastic measures should be-
come necessary.
The means by which ducks find their
way from their breeding to wintering
grounds has been under investigation.
Juvenile blue-winged teals were captured
in migration in Illinois and held in cap-
tivity until all the other blue-winged
teals had migrated south of the United
States (Bellrose 19582). They were then
banded and released. From _ recoveries
of bands it was found that these juveniles,
though unfamiliar with the route, flew
southward along lines of flight similar to
those of adults. Experiments with wild
mallards demonstrated an ability to orient
by celestial means (Bellrose 1958d).
The initial flight of mallards released in
unfamiliar areas was northward on clear
days or nights and in apparently random
directions when skies were cloudy and
sun and stars were obscured.
The Mourning Dove.—The mourn-
ing dove became the subject of an in-
tensive research effort in the autumn of
1948 when it was seen that data were
needed for an objective evaluation of
claims that doves were being shot to ex-
tinction by hunters in Illinois. The kill
of doves in 1946 and 1947 was estimated
from hunter reports to have been 200,000
in each year and about 300,000 in 1949
(Hanson & Kossack 1950:31). It was
later determined that the kill was fairly
evenly distributed over the state (Mar-
quardt & Scott 1952).
A program of dove banding, particu-
larly of nestlings, was undertaken to de-
termine points of origin of populations.
Banding by amateur co-operators was en-
couraged (Kossack 1955), and a _ tech-
nique employing elastic adhesive tape to
secure bands on small nestlings was de-
veloped (Kossack 1952). ‘These aspects
of the program were later adopted on a
country-wide scale by the U. S. Bureau
of Sport Fisheries and Wildlife.
A portable candler was constructed for
aging dove eggs in the field (Hanson
1954). Photographic and _ descriptive
guides for aging incubated eggs and
nestlings were prepared (Hanson & Kos-
sack 1957a). The predominance of uni-
sexual broods in mourning doves was
found in early studies (Kossack & Han-
son 1953). This subject is being treated
December, 1958 ScoTT:
in greater detail in a report, now in
preparation, on sex ratios in doves.
The effort to appraise mortality among
mourning doves included study of their
parasites and diseases (Kossack & Han-
son 1954; Levine 1954; Hanson, Levine,
Kossack, Kantor, & Stannard 1957). The
paper by Hanson ef al. describes the
ectoparasites of doves and the arthropod
fauna of their nests and summarizes the
results of a 7-year study of the incidence
of blood parasites in relation to ages of
the doves and to regions of the state.
The relation of age and the stages of
wing molt to body weight, body fat, and
migration habits was studied (Hanson &
Kossack 19574). In contrast to interpre-
tations of fat deposition in passerines, the
analysis of data on fat deposition in
mourning doves showed no consistent re-
lationship to migratory habits, but instead
proved to be related to the energy de-
mands of the molt, regional farming prac-
tices, soil fertility, and food habits. Doves
that had fed almost exclusively on corn
in good soil areas had formed relatively
heavy amounts of fat; most of those taken
on poor, sandy soil where they fed largely
on seeds of wild plants had formed little
or no fat.
After 10 years of study there is still
no evidence that dove populations in IIli-
nois are controlled by hunting. Popula-
tion declines which have taken place are
generally traceable to habitat destruction,
disease, and adverse weather.
Mammals
To the wildlife historian the apparent
lack of interest in mammals by early re-
searchers of the Natural History Survey
and its predecessors constitutes something
of an enigma. Almost half a century
slipped away before Forbes, upon receiv-
ing a letter from C. A. Rowe of Jackson-
ville in April of 1907 reporting the de-
struction of seed corn by moles and en-
closing the stomach contents of a mole
containing about 65 per cent corn, was
stimulated to authorize research on a
problem in economic mammalogy (West
1910:14). The resulting studies (Wood
19106; West 1910) provided the first evi-
dence that moles included corn, or any
substantial amount of plant food, for
that matter, in their diet.
WILDLIFE RESEARCH 195
Fur-Bearing Mammals.—Forbes
(19124) included fur-bearing mammals
among the animal resources of Illinois,
but a program of consequence did not
get under way until the 1930’s, when
evaluations of fur resources were under-
taken.
Neither technical nor popular interest was
great enough to focus further attention of
the state’s research agencies on furbearers
until, in 1930, David H. Thompson, E. C.
Driver, and D. I. Rasmussen of the Illinois
Natural History Survey staff borrowed trap-
pers’ reports... from the Illinois State De-
partment of Conservation, to which law
provided that each licensed trapper report
his catch monthly during the trapping season
(Mohr 1943a:505).
Brown & Yeager (1943:437) stated
that some of the figures derived by Driver
and Rasmussen were published in the
Blue Book of the State of Illinois (Frison
1931, 1933).
Following a limited survey of helminth
parasites in fur-bearing animals collected
during the hunting seasons of 1935-36
and 1936-37, Leigh (1940:191) stated
that “A study of the literature offers lit-
tle information on pathogenicity of the
parasites found in the hosts studied.’
This shortcoming in our knowledge con-
tinues to prevail.
The desire to obtain a reasonably re-
liable evaluation of the fur resource in
Illinois eventually resulted in two im-
pressive reports (Brown & Yeager 1943;
Mohr 1943a). Brown & Yeager (1943)
based their evaluation on an intensive
oral survey covering the 1938-39 and
1939-40 trapping seasons, and Mohr
(1943a) made an analysis of fur-taker re-
ports beginning with the 1929-30 trap-
ping season and ending with that of
1939-40, excepting the 1931-32, 1932-
33, and 1933-34 seasons. The results
obtained by the two methods were rela-
tively similar. The average value of the
annual fur catch was estimated to have
been a little over $1,000,000, about 80
per cent of which represented returns for
muskrats and minks. To aid in investiga-
tion of fur-bearing animals, Yeager
(1941a) assembled a bibliography of over
2,600 references on North American fur
animals.
Some valuable contributions on the
relationship of muskrat populations to
196 I-tinois NATuRAL History SurvEY BULLETIN
fluctuating water levels in bottomland
lakes flanking the Illinois River have been
made by Natural History Survey re-
searchers. Bellrose & Brown (1941 :207)
observed that the numbers of muskrat
houses
were nearly six times as many in lakes with
a stable, as in those with a semistable, water
level and there were twice as many lodges
per acre in lakes with a semistable, as in
those with a fluctuating, water level.
Stable water levels favored the growth
of those species of aquatic plants most
desirable for muskrats. Later, following
an investigation of the response of musk-
rat populations to flood and low water
levels in these bottomland lakes, Bellrose
& Low (1943:187) concluded:
While muskrats may be harassed and deci-
mated within a short time during flood con-
ditions, those living under low water condi-
tions may escape without serious loss in
summer but may be seriously affected during
cold, winter weather.
In 1940-41 and 1943-44 Bellrose
1950) developed a new technique for
evaluating the food preferences of musk-
rats by comparing the proportions of plant
foods taken from “feeding” lodges in mid-
winter with the proportions of plants
known to have been within the feeding
range of the muskrats. Cattail was rated
the most preferred food. The capacity of
vegetative types to support muskrat popu-
lations was determined by recording the
density of muskrat lodges in each vegeta-
tion type. River bulrush and cattail had
the greatest population values.
Advantage was taken of two unusually
fine opportunities for measuring the re-
sponse of raccoons to a food windfall of
ducks (Yeager & Rennels 1943) and
geese (Yeager & Elder 1945) made avail-
able as hunters’ crippling losses at the
Pere Marquette Wildlife Experimental
Area immediately above the confluence of
the Illinois and Mississippi rivers and at
the Horseshoe Lake Game Refuge in
Alexander County. At the Horseshoe
Lake Game Refuge, where crippling
losses were alarmingly high, bird remains,
chiefly those of Canada geese, occurred
in 20.7 per cent of the raccoon droppings
collected a day after the hunting season
opened and in 87.9 per cent of the drop-
pings collected 3 weeks after the close of
Vol. 27, Art. 2
the season (Yeager & Elder 1945:49-
51). In 1939 and 1940, on the Pere
Marquette Wildlife Experimental Area,
duck remains did not occur in raccoon
droppings collected before the opening of
the waterfowl season, but after opening
of the season “remains of mallard, pin-
tail, and wood duck were 89 per cent of
the bird material in 1939, and 76 per cent
in 1940” (Yeager & Rennels 1943:59).
These findings indicate that crippled
waterfowl may not constitute a complete
loss, inasmuch as furbearers utilize them
as food. The biology of the raccoon is
currently under intensive study by Glen
C. Sanderson.
A survey of the population and distri-
bution of beavers in Illinois was con-
ducted under a co-operative Federal Aid
project from April 1, 1947, through June
30, 1951. It was found (Pietsch 1957:
193-6) that beavers were “last reported”
in Illinois in 1912, were reintroduced in
1929, were estimated to number 3,565 in
45 counties in 1950, and were reported
from 55 counties in 1954.
The red fox was made the subject of
a thorough evaluation (Scott 1955) be-
cause the values of this colorful mammal
were believed to have been regularly
underrated. This evaluation was based on
personal experience extending over 20
years and a number of intensive investi-
gations (Scott 1943, 1947; Scott & Klim-
stra 1955) especially relating to the red
fox as a predator. As a result of
this evaluation, Scott’ (1955:14) recom-
mended:
1. The encouragement of an increased use
of red foxes for sport hunting, . .
2. The education of those who hope for
increased small game populations through fox
extermination campaigns to the more con-
crete and lasting results that may be expected
from habitat improvement programs... .
3. The elimination of bounty payments on
red foxes.
4. The enactment and enforcement of more
effective antirabies laws, especially as ap-
plied to the compulsory vaccination and
quarantine of domestic dogs, and prompt re-
duction by organized trapping of red fox
populations in which rabies epizootics occur.
5. The increased attention by game man-
agers to the proper management of the red
fox resource in general, including assistance
with the cropping of surplus animals in areas
where adequate cropping has not been ac-
complished by hunters.
December, 1958
Game Mammals.—tThe cottontail
rabbit tops the list of game mammals in
Illinois in a number of respects. In a
survey of license-stub kill cards for the
1950-51 hunting season, Marquardt &
Scott (1952:4) found that rabbits pro-
vided twice as many sportsmen with game
in the bag as did any other game species
and numbered more than twice as many
as any other kind of game animal re-
ported. Rabbits constitute the chief game
animal of the state largely because they
are widely distributed and because they
possess the reproductive potential to main-
tain themselves despite high mortality, in-
cluding that from severe hunting pressure.
Proving that there is some bad with
the good, however, is the fact that tula-
remia, a disease which is transmissible to
man, occurs in rabbits. “In the period
1926-1949, Illinois had more than 3,000
reported cases of human tularemia, about
twice as many as any of the other states”
(Yeatter & Thompson 1952:351). Yeat-
ter & Thompson (1952:379) reported that
“The human tularemia rate in any year
in Illinois seems to be determined both by
temperatures about the time of the open-
ing of the rabbit season and by the
abundance of rabbits.’ They concluded
that the incidence of human tularemia in
Illinois could be reduced by delaying the
opening of the rabbit hunting season until
about December 1. As a result of these
findings, the opening of the hunting sea-
son in Illinois was postponed until No-
vember 26 in 1955. In recent years meth-
ods of treating tularemia in humans have
been greatly simplified by the use of anti-
biotics. It seems certain, however, that
most hunters will prefer not to depend
upon antibiotics—that they will enjoy
their rabbit hunting far more knowing
that by hunting within a season which
opens after the onset of sharp freezing
weather they and their families are ex-
posed to the hazard of tularemia only to
a minimum extent.
Yeatter & Thompson (1952:378)
recommended, as a refinement to their
studies, further study of ticks, other tula-
remia vectors, and the biology of the
rabbit. Ecke (1955:294-6) recorded a
complete description of the courtship and
mating of cottontails. Also, Ecke (1955:
305) found evidence which suggested
Scott: WILDLIFE RESEARCH 197
“that some component of green vegeta-
tion, possibly Vitamin E, is responsible
for stimulating the pituitary glands of
rabbits into the secretion of somatic nutri-
tives, and consequently, determining the
breeding conditions of the animals.”
Dr. Rexford D. Lord (1958:274)
has recently constructed life tables which
indicate that as many as 24 to 27 per cent
of the rabbits available to hunters in
autumn may be the young of rabbits born
in the spring of the same year.
Ecke & Yeatter (1956:212-3) at-
tributed the death of a rabbit, estimated
to have been about 13 days of age, to
coccidiosis and suggested further study of
coccidiosis as a cause of mortality among
rabbits. Detailed studies of ectoparasites
of rabbits have been carried on since 1952
by Dr. Lewis J. Stannard, Lysle R.
Pietsch;.Dr. Carlb.Os Mohr, and «Dr.
Lord.
The realization that tradition for a
summer hunting season on squirrels in
Illinois was not biologically sound touched
off a thorough investigation (Brown &
Yeager 1945) of fox squirrels and gray
squirrels in 1940. The chief objection to
a summer hunting season was that it re-
sulted in the killing of pregnant and lac-
tating females. Brown & Yeager (1945:
526) estimated that summer hunting re-
sulted in a wasteful loss of 31.8 unborn
and suckling squirrels for each 100 squir-
rels bagged. Because the tradition for
summer hunting was strong and because
squirrel hunting was good in some parts
of the state despite early hunting seasons
in the past, Brown & Yeager (1945:
526-8) believed it unwise to enact a sea-
son beginning so late that it would pre-
vent all losses resulting from the killing
of pregnant and lactating females and
they observed: “Such a season could hard-
ly begin earlier than October 1, and it
would certainly be opposed by a large
number of hunters.’ A compromise sea-
son of September 15 to November 15 in
central and northern I]linois and Septem-
ber 1 to October 31 in southern Illinois
was recommended. This recommendation
has not been accepted by Illinois hunt-
ers.
The report by Pietsch (1954) on deer
populations in Illinois will be of especial
value to the future wildlife historian,
198
Pietsch reported upon the early history of
the deer in Illinois, recent populations,
and management. Hunting was suggested
as'a means of control, and the deer sea-
son, after being closed for 56 years, was
opened in 1957 for hunting with bows
and shotguns.
Miscellaneous Contributions to
Mammalogy.— Mohr (19434, 1947a)
appraised population data for small mam-
mals in North America. He calculated ~
the weight of specific populations within
the area occupied and concluded that
population densities within groups of
mammals having similar feeding habits
were limited by the size of the mammal
concerned. Also, Mohr (19474) recorded
miscellaneous data on populations of cer-
tain mammals in Illinois for future refer-
ence.
On December 1, 1956, a grant-in-aid
was made by the National Institutes of
Health of the U. S. Public Health Serv-
ice to initiate a 3-year study of epizootiol-
ogy of rabies in wild mammals. This in-
vestigation is aimed at identification of
the key hosts to rabies in Illinois and
those factors that make them key hosts.
WILDLIFE MANAGEMENT
“Applied programs in the field of bio-
logical science are seldom, if ever, de-
veloped without the aid of years of pa-
tient, so-called unapplied, researches”
(Frison 19424:5). Frison believed that
sufficient basic knowledge had been ac-
cumulated to support applied manage-
ment programs of an exploratory nature,
and, with characteristic vigor, he encour-
aged work of this kind in the late 1930's.
Later, he insisted that these programs be
evaluated for monetary return, wildlife
yield, and other benefits.
Two of these early programs concerned
management of upland wildlife in central
and northern Illinois. One of the first
attempts to develop wildlife habitat on
intensively cultivated land took place on
the Urbana Township Wildlife Area,
which was believed “typical of the best
Illinois cornbelt farmland” (Hessel-
schwerdt 1942:31). Habitat develop-
ment was begun on this area in 1937,
and in 1939 the project came under the
Federal Aid program. Development fea-
Ittinois NATURAL History SurvEY BULLETIN
Vol. 27, Art. 2
tures included fencerow plantings, instal-
lation of den boxes, block planting, and
protection of strips along drainage ditches.
Usage of the den boxes was evaluated.
Fox squirrels appeared to extend their
range and to increase in numbers as a
result of the provision of den boxes
(Hesselschwerdt 1942:33-4, 36). Usable
den boxes are no longer present on the
area, and resident fox squirrels are un-
common. As the fencerow plantings ma-
tured, cottontail rabbits and songbirds in-
creased in numbers (Wandell 1948 :262-
3), but populations of pheasants and quail
have shown no appreciable increase.
Minks and muskrats trapped along an un-
grazed section of a drainage ditch in
1944-45 provided an estimated per-acre
income of $62.78, more than 10 times
that produced by the same ditch where it
was heavily grazed (Yeager 1945:85).
On October 1, 1939, a Federal Aid
project to determine the availability of
land for wildlife habitat on the inten-
sively cultivated farm land of the Illinois
dark prairie was initiated (Spooner &
Yeager 1942). Land for refuges and
cover development was found to be avail-
able, without purchase, in small scat-
tered tracts, and obtainable through long-
term easements. Spooner & Yeager (1942:
54) concluded that “Although the proj-
ect shows promise of wide application on
the Illinois prairie, there are yet many
problems which must be further an-
alyzed before its entire success is proved.”
Natural History Survey staff members
have participated in various other pro-
grams closely related to management of
upland wildlife. The Survey sponsored
the initial acquisition in 1940, by the
Department of Conservation, of a tract
of sand prairie and wet land in Lee Coun-
ty, the Green River Area, as a manage-
ment area for prairie chickens, water-
fowl, and other animals. It is believed
that this tract of land has played an im-
portant part in maintaining the only siz-
able flock of prairie chickens surviving
in northern Illinois. However, unless the
area is managed with primary considera-
tion for the original objectives, it may
well go down in history as the place
where native prairie chickens met their
end in northern Illinois. Frank C. Bell-
rose proposed the purchase of the Rice
-“
a
December, 1958 SCOTT :
Lake Wildlife Area by the state in 1942,
and the area, now the best duck area in
the state, was purchased by the Illinois
Department of Conservation in 1943.
In 1955 a Federal Aid research proj-
ect was initiated by Southern Illinois
University, the Illinois Department of
Conservation, and the Illinois Natural
History Survey to determine the economic
values and benefit to wildlife of wide-
row culture of corn in southern Illinois.
Potential benefits, to the farmer, of wide-
row culture and interplanting with cover
crops included conservation of soil, in-
crease of fertility, elimination of the low-
paying oat crop in rotations, saving of
labor, and yields of corn comparable to
those from conventional cultural methods
(Vohs 1957).
The extent of use of wide-row corn-
fields by wildlife varied with the at-
tractiveness of the interseeding. How-
ever, comparable observations on the
numbers of wildlife in wide-row fields
and standard interval fields revealed ra-
tios of 5 to 1 for bobwhite quail, 12 to 1
for mourning doves, and 6 to | for cot-
tontail rabbits. Wide-row corn is con-
sidered to have great potential for wild-
life management especially, because it
provides for an increase in wildlife values
in thousands of acres of corn.
Evaluations of wildlife populations and
possibilities for their management were
made on marginal lands. Analyses were
made of possibilities for management of
coal-stripped land for the benefit of up-
land game and furbearers (Yeager 1941),
1942), management of agricultural drain-
age systems for production of furbearers
(Yeager 1943), and yields of fur from
animals produced on different types of
land (Yeager 1945). Another project
concerned the use of hunting dogs in
sport and conservation (Yeatter 1948).
Levee and drainage districts have re-
duced the flood plain along the Illinois
River by almost half, about 200,000
acres. In view of the resulting loss of
recreational opportunities and the in-
creased danger from floods, Bellrose
(1945) made a survey of the relative
values of drained and undrained bottom-
lands. Later, Bellrose & Rollings (1949)
calculated the annual per-acre value, to
the public and to owners, of bottomland
WILDLIFE RESEARCH 199
lakes of the Illinois River valley. They
concluded that bottomland lakes in the
Illinois River valley had an annual per-
acre value to the public, 1944-1947, of
$26.35, made up as follows: duck hunting
$12.18, angling $2.40, commercial fishing
$9.65, and fur trapping $2.12; they esti-
mated that privately owned lakes were
capable of producing an average yearly
gross return to owners of $18.57 per acre
(Bellrose & Rollings 1949:23).
Following an investigation of the ef-
fects of flooding on mammals in and
around a bottomland lake in the Illinois
River valley, Yeager & Anderson (1944:
178) concluded that ‘The effect of flood-
ing on mammals ranged from heavy
mortality in the case of woodchucks to
apparently little basic change in the be-
havior of minks.” For various kinds of
fur-bearing and game mammals, Yeager
(1949) recorded the changes in abun-
dance caused by permanent flooding of
wooded bottomland over an 8-year pe-
riod, 1939-1946. The site was a tract
of 600 acres in the junction of the Mis-
sissippi and Illinois rivers; the area was
flooded in 1938 by closing of the gates
of the then new Alton dam.
THE FUTURE
Because the wildlife resource and the
environment essential to its existence
have economic and recreational values
beyond general public appreciation and
because knowledge on which to base in-
telligent management of this resource is
in the best interest of the people of I[]li-
nois, I believe that we must plan for the
future of wildlife research in Illinois as
a part of our evaluation of the past.
Forbes (1907c:892) expressed
view when he wrote
this
that we are... practically interested in what
has come and gone only as it may help us to
bring a new thing into being in a way to se-
cure its permanent continuance and its normal
growth.
In the past the wildlife research pro-
gram of the Illinois Natural History
Survey has been heavily weighted toward
investigations of migratory game birds.
These investigations have been extremely
valuable and must be continued in the
200
future; however, increasing attention
must be given to other wild species, in-
cluding nongame species. Nongame spe-
cies must be studied not only because
they represent economic and _ esthetic
values but also because some of them,
such as mice, are especially useful in basic
research. Responsibility for research on
certain species cannot be side-stepped on
the ground that effective study of these
species is being carried on in other states,
for Illinois has problems characteristic of
its own land-use pattern and it bears a
responsibility to other states inasmuch as
enlightenment on particular problems is
often best obtained through comparison
of range-wide differences.
While it is true that great progress
has been made in wildlife research, and
the number of unknowns has been re-
duced, this increased knowledge has ex-
panded our awareness of unknowns.
Many research techniques have been de-
veloped, but, in most instances, the de-
gree of their reliability has not been
adequately determined, and refinement is
desirable. Although the research has been
increasingly objective, it must be ad-
mitted that there is need for improve-
ment. The expanding field of wildlife
research requires specialization, but it also
requires integration and synthesis.
This post-mortem of wildlife research
impresses me with the fact that the qual-
ity of a contribution is influenced not
only by the capabilities of the individual
researcher but also by the length of time
devoted to concentrated effort on par-
ticular problems. If real progress is to
be realized in the future, the sustained
and concentrated effort of top-flight re-
searchers must be insured. Illinois will
stand among the leaders in wildlife re-
search only so long as the means with
which to attract and hold qualified per-
sonnel for extended periods is provided.
Provisions must be made for long-range
research, with monographic-type publica-
tion being an objective. And, finally, we
must guard against becoming desk- and
laboratory-bound theorists and interpret-
ers. It is essential that contact be main-
tained with living organisms in their nat-
ural surroundings.
Much of our research effort has moved
in the direction of life history, ecology,
ILtinois NAruRAL History Survey BULLETIN
Vol. 27, Art. 2
and populations. And much of it must
continue to move in this direction. How-
ever, means for improvement must be
constantly sought out. In life history
studies, we must be increasingly objec-
tive. In ecology, we must be mindful of
the need for land-use practices which are
compatible with the best interests of both
landowners and _ wildlife, especially in
view of the increasing use of marginal
-land and agricultural chemicals. In the
area of population mechanics, we must
not only measure population trends and
population composition; we must also
seek and evaluate with greater refinement
those factors which influence population
trends and make-up.
In the future more attention must be
given to fields of study only lightly
touched upon in the past. Animal be-
havior, a vital and challenging field, must
be explored particularly, for what an ani-
mal does is more important to the wild-
life manager than what it is. Mobility,
especially migration, must be examined
more critically. Nutrition, qualitative as
well as quantitative, must be investigated,
and techniques for evaluating “condition”
in wildlife must be explored. Anatomy,
embryology, genetics, physiology, and
biochemistry must, of necessity, play a
larger part in the evaluations of the
future.
We must guard against the neglect or
shunning of certain research by avoiding
a “that’s been done before’ philosophy.
It may well have been done before, but
we must be careful to evaluate the
thoroughness with which it was done.
We must examine it for weaknesses and
for its value as a basis for new working
hypotheses.
The wildlife research of the Natural
History Survey has been instrumental in
bringing about desirable changes in estab-
lished policies and practices and in the
establishment of new policies and prac-
tices which affect wildlife. We must pro-
vide adequate bases for the policy making
of the future. To these ends we must
move in the direction of prompt publica-
tion, and we must make certain that use-
ful publicity is given especially to those
findings which indicate that support of,
or changes in, practices or administrative
policies are desirable.
Oe ee ee ee ee ee ee ee
ee ee ee ee
‘al ~ =i bao
December, 1958 Scorr:
Our thinking must be projected far
into the future in an effort to visualize
those areas where knowledge will be most
needed. Anticipating the future is ad-
mittedly fraught with pitfalls. It seems
certain, however, that human populations
will continue to increase in Illinois. This
increase will be attended by more inten-
sive use of land and water, more exten-
sive transportation and communication
systems, more extensive residential and
industrial areas, more exhaustive use of
fuels and metals, greater use of atomic
energy, more automation, and more lei-
sure time.
From the wildlife manager’s point of
view, this condition forewarns of an in-
creasingly severe competition between
wildlife and basic human needs. When
it is considered that wildlife must be pro-
duced primarily on lands utilized for
other purposes, the problems of the fu-
ture for wildlife become obvious. The in-
creasing demand for human food will
make it essential that harvest methods be
refined to reduce waste, that more heavily
yielding crops be developed, that more
marginal land be brought into use, and
that more agricultural chemicals be ap-
plied. This promises not only to reduce
wildlife populations but to force them
below minimum survival levels, unless
effective provisions, such as wide-row
corn may prove to be, are constantly
sought out by wildlife managers. The
need for refuges to insure the survival
of rare species will increase. The relative
importance of those wild animals which
compete with humans for food by eating
or contaminating it will be magnified.
Intensive use of water could create a
WILDLIFE RESEARCH 201
pollution problem such as would virtually
deny aquatic life outside protected areas,
unless pollution control, including provi-
sion for disposal of radioactive waste,
keeps pace with increased water utiliza-
tion.
The provision of a means for satisfy-
ing the psychological needs of a human
population with more leisure time and
relatively less elbow room comprises a
formidable challenge. If the human pop-
ulation is to maintain some semblance of
sanity, services such as those offered by
wildlife biology must be given equal
recognition with those of the physical
sciences. Perhaps the average family of
the future will tend to satisfy more of
its needs for pleasure in the out-of-doors
and for escape from the pressures of civi-
lization in its own backyard. Hence, the
wildlife manager should contrive to know
more about the management of the home
landscape for wildlife. It seems certain
that an increasing amount of hunting will
take place on regulated shooting areas,
that is, unless hunting proves to be good
in outer space.
The wildlife manager’s problems of
the past, considerable as they have been,
seem as child’s play compared with those
looming in the future. The wildlife man-
ager is going to need determination, cour-
age, ability, compensation, and means such
as never before. Perhaps we can ease
some of his problems by the effective
planning of current research to provide
a sound basis for the essential decisions
of the future. Indeed, wildlife manage-
ment as a profession may well depend on
the soundness of today’s plans for the
future.
Publications and Public Relations
ANY of the men whose names were
written large in the early annals of
the Illinois Natural History Survey had
been educated in the classical tradition.
Most of the physicians, educators, and
others whose formal schooling included
college had undergone the discipline of
Latin and Greek studies.
Jonathan Baldwin Turner, elected first
president of the Illinois Natural History
Society in 1858 (Bateman 18584:258),
was a graduate of Yale College and for
many years Professor of Belles Lettres,
Latin, and Greek at Illinois College,
Jacksonville (Carriel 1911:12, 46).
Charles E. Hovey, first secretary of the
Society (Bateman 18584:258) and first
head of the Illinois State Normal Uni-
versity, was a graduate of Dartmouth
College (Marshall 1956:28). Joseph Ad-
dison Sewall, early curator, had studied
at both Yale and Harvard and was a
graduate of Harvard Medical College
(Marshall 1956:78).
Benjamin Dann Walsh, first State
Entomologist, was a graduate of Trinity
College of Cambridge University in Eng-
land (Weiss 1936:234). William Le
Baron, second State Entomologist, was,
like Sewall, a graduate of Harvard Med-
ical College (Goding 1885:122).
Although Stephen Alfred Forbes,
fourth State Entomologist, first and only
Director of the State Laboratory of Nat-
ural History, and first Chief of the Nat-
ural History Survey, had comparatively
little formal education as a youth, he had
subjected himself to the discipline of lan-
guage study. At home he had studied
French and Spanish, and in Confederate
prisons during the Civil War he had
spent some of his “abundant leisure” in
studying Greek from books he managed
to buy at Mobile (Howard 1932:6).
The early leaders in Illinois science,
most of them classicists before they were
scientists, had developed respect for the
meaning and sound of words, and had ac-
quired a skill in word usage that carried
into their scientific writings.
JAMES SS. Ae
Trained in the classics though most of
these leaders were, many were neverthe-
less aware that classical education had
limitations. They saw that in Illinois, in
the middle of the nineteenth century, edu-
cation must be brought out of ivied halls
to the furrow and the work bench.
In the Illinois College classroom Tur-
ner was a teacher of Latin and Greek.
Out of the classroom, he was a leader in
the movement for industrial education,
the education of the farmer and the me-
chanic.
Turner asked (Carriel 1911:76):
But where are the universities, the appara-
tus, the professors, and the literature spe-
cifically adapted to any one of the industrial
classes? . . . society has become, long since,
wise enough to know that its teachers need to
be educated; but it has not yet become wise
enough to know that its workers need educa-
tion just as much.
Socrates, Cincinnatus, Washington,
Franklin, and other worthies, Turner ar-
gued, derived their education “from their
connection with the practical pursuits of
life” (Carriel 1911:117):
What we want from schools is to teach men
. .. to derive their mental and moral strength
from their own pursuits, whatever they are,
and to gather from other sources as much more
as they find time to achieve. We wish to teach
them to read books, only that they may the
better read and understand the great volume
of nature ever open before them.
Can, then, no schools and no literature,
suited to the peculiar wants of the industrial
classes, be created by the application of science
to their pursuits?
Walsh (18684:9) emphasized that his
annual report as Acting State Entomolo-
gist was “intended chiefly for the use of
common folks.”
Writing as Editor of the only volume
of Transactions published by the Natural
History Society itself, C. D. Wilber
(1861d:3-4) epitomized the educational
movement of the time, a movement that
might be termed a revolt of the classicists
against the classical tradition:
It has been the aim of the Editor, to present
only such articles and papers as are immedi-
ately useful and interesting to the citizens and
[ 202 ]
ee EOS ee
pe a Le Se
et st
CO eG ee Rn OS ee et ae anes
December, 1958
schools of Illinois, with a hope that a zeal for
the pursuits and studies of Natural History
may spring up among our people, like the seeds
of the sower, in the parable, falling upon good
soil, and yielding, ‘some sixty and some an
hundred fold.”
In order to render the greatest good to all,
the subjects have generally been treated in a
popular rather than a technical style. It has
been said, that he who places a valuable truth
or fact within the reach of the million, is doing
more for humanity than he who discovers it.
And, indeed, if scientific men, or libraries and
museums, cannot contribute to the elevation of
the masses who are less privileged, their use-
fulness is questionable.
The ideas reflected in TTurner’s ques-
tions and answers and in Wilber’s com-
ments culminated in the Morrill Act of
1862, in land grant colleges, and, spe-
cifically, in the Illinois Industrial Uni-
versity at Urbana. Both cause and effect
of the movement for general education
was the increasing thirst that Illinois
people in the middle of the nineteenth
century had for knowledge, the growing
conviction that information should be
widely disseminated. “—The movement led
to the formation of, and was abetted by,
the Illinois State Horticultural Society,
the Illinois State Agricultural Society,
and the Illinois Natural History Society.
The Natural History Society was not
an accident nor an isolated segment of
history. It was part of a contagious
movement sweeping the prairies. As seen
by Wilber (1861d:7):
The demand for this movement seemed to
proceed from a want of accurate knowledge in
nearly all departments of Natural History in
the State; and also, from a desire that all facts
and discoveries in a field so vast as Illinois,
should be made immediately subservient to
the great ends of popular education.
EARLY PUBLICATIONS
The Illinois scientist in mid-nineteenth
century looking for means of disseminat-
ing knowledge had few publication out-
lets. Among the small number of scien-
tific journals published before 1860 were
The American Journal of Science, found-
ed in 1818, the Entomologist of London,
in 1840, and the Boston Journal of Nat-
ural History, in 1834. The first Trans-
actions of the Illinois State Agricultural
Society were published in 1855; the first
Transactions published by the Illinois
AYARS: PUBLICATIONS AND PUBLIC RELATIONS 203
State Horticultural Society itself were
dated 1863. The first Proceedings of the
Entomological Society of Philadelphia
were published in 1861. The American
Naturalist was not founded until 1867,
the Botanical Gazette not until 1875.
The Prairie Farmer had been estab-
lished at Chicago in 1841, and to this pe-
riodical, frankly slanted toward the in-
terests of practical farmers, Illinois sci-
entists of mid-century turned for publica-
tion of their technical papers. The pub-
lication by Prairie Farmer of many of
these papers, some significant enough to
attract the attention of eminent scientists
in other parts of the country, is indication
of the extent to which the classicists and
the industrialists had become wedded.
That publication of scientific papers
was an important aim of the founders of
the Illinois Natural History Society is
evident from written records of the or-
ganization. The object of the Society, as
outlined by Cyrus Thomas in his letter
read before Illinois teachers meeting in
Decatur, December 29, 1857 (Bateman
1858a:12),
shall be the investigation and study of the
Flora, Fauna, Geology, and Mineralogy of
Illinois, and the illustration of the same by
gathering specimens, exchanging the same, and
by publishing such meritorious works thereon
as the authors may present, ...
At the last session of its second meet-
ing, held on June 20 and 21, 1859, at
Bloomington, the Society (Francis
1859 :664) resolved that “the Execu-
tive Committee be required to procure
the publication of the papers and proceed-
ings of the Society in some paper gener-
ally circulated through the State.” The
Executive Committee in turn resolved
that, ‘in accordance with the resolution
of the Society, we select THE PRAIRIE
FARMER as its medium for publishing the
papers and proceedings of the Society.”
Another outlet for papers written by
members of the Natural History Society
was provided by the [llinois State Agri-
cultural Society. In its own published
Transactions the Agricultural Society in-
cluded the V'ransactions of the first three
meetings of the Natural History Society
and several papers contributed by mem-
bers (Francis 1859a, 18595, Wilber
1861a).
204
In 1861 the Natural History Society
itself published what it termed the ‘‘Sec-
ond Edition” of Volume I, Series I, of
its Transactions (Wilber 1861d). Most
of the material in this volume had been
printed previously by the Agricultural
Society in its Transactions for 1857-1858
(Wilber 1861a). Wilber’s Preface to the
volume published by the Natural History
Society was dated October 30, 1861
(Wilber 1861d:4). The Civil War had
begun 6 months before.
In 1867, after the War was over and
men again had time to consider civilian
science, the state legislature in a single
session made an appropriation to the I[Ili-
nois Natural History Society, provided
for a State Entomologist, and authorized
establishment of the Illinois Industrial
University (Illinois General Assembly
1867).
The legislative act that provided for a
State Entomologist required him to pre-
pare “a report of his researches and dis-
coveries in entomology for publication by
the state, annually” (Illinois General As-
sembly 1867:36).
The act of 1867 in which state appro-
priations were first made to the Illinois
Natural History Society and the act of
10 years later establishing the Illinois
State Laboratory of Natural History
made no mention of publications (Illinois
General Assembly 1867:21-2; 1877:
14-6). In 1879, however, the state leg-
islature appropriated to the State Lab-
oratory for ‘“‘publication of bulletins, the
sum of two hundred and fifty dollars per
annum” (Illinois General Assembly
1879:42).
An act approved June 27, 1885, a few
months after Forbes had moved to Ur-
bana, was specific about publication. It
stipulated that the Director of the State
Laboratory “shall present for publica-
tion, from time to time, a series of sys-
tematic reports covering the entire field of
the zodlogy and the cryptogamic botany of
Illinois.” The act appropriated ‘for the
publication of bulletins, the sum of three
hundred dollars per annum, and for the
preparation and publication of the second
volume of the report upon the zodlogy of
the State, the sum of fifteen hundred
dollars per annum”’ (Illinois General As-
sembly 1885 :23-4).
ItLinois NaturAL History SurvEY BULLETIN
Vol. 27, Art. 2
The following year, Forbes staged an
intellectual sit-down strike over a_pro-
posed publication. Insufficient funds and
conflicting legalities would not permit
him to include what he considered suit-
able illustrations in the State Entomolo-
gist’s report he had prepared for publica-
tion in 1886.
Forbes (1886a:3) explained the situa-
tion in the preface to a group of articles
that he and members of his staff had writ-
ten and that he had submitted to the
State Board of Agriculture for publica-
tion in its Transactions:
A recent opinion of the Attorney General
makes it doubtful whether the State Entomolo-
gist of Illinois has the right, under the laws
referring to that office (to some extent incon-
sistent and conflicting), to prepare any other
than a biennial report; and a change in prac-
tice of the State Board of Contracts leaves no
doubt whatever that a report published this
year could not be illustrated. As an elaborate
monograph of insects injurious to Indian corn
was intended as the principal part of my ento-
mological report for 1885, and as this article
certainly should not be published without a
large number of excellent figures, I have de-
cided, under existing circumstances, not only
to withhold this paper, but also to refrain from
presenting any formal report for 1885, leaving
it to the State Legislature to provide for the
proper illustration of the reports hereafter, and
to remove the present inconsistencies of the
law. Unwilling, however, that the work of the
office of the past year should be without repre-
sentation in the Transactions of the State
Board of Agriculture, with which the ento-
mological report has been annually published
for the last ten years, I have submitted to the
Board, at the request of its Secretary, C. F.
Mills, Esq., the following miscellaneous essays
on economic entomology, summarizing the re-
sults of such part of our operations as may
well be published without cuts.
At its next session the Illinois Gen-
eral Assembly (1887:72) appropriated to
the State Laboratory of Natural History
$300 for publication of Laboratory bul-
letins and $500 for “the illustration of
the biennial report of the State Entomol-
ogist.”
In these days of high cost of printing,
engraving, and other services, such sums
as $300 and $500 seem insignificant. In
1887, however, they bulked large enough
to help confirm in the public mind the
importance of publication and _ illustra-
tion in scientific research.
In a biennial report issued about 3 years
after assuming his duties in Urbana,
2. oe 7
December, 1958
Forbes (1888:7) described in detail the
publications that were being issued under
his direction:
Our regular publications run in four series,
two from the Laboratory and two from the
Office of the State Entomologist,—the former
comprising the State zoological report and the
bulletins of the State Laboratory of Natural
History, and the latter the biennial entomolog-
ical report and the bulletins of the entomolog-
ical office.
During the past two years we have finished
the printing of the first volume on the zoology
of the State,—containing five hundred and
twenty pages of text and forty-six plates,—
devoted to the ornithology of Illinois as far as
the water birds. This is a reprint of the vol-
ume, the first edition having been entirely de-
stroyed in the burning of the office of the State
Printer last February.
PUBLICATIONS SERIES
The words “Volume I, Series I,” at the
top of the title page of the only Trans-
actions published by the Illinois Natural
History Society under its own name are
evidence that the members looked for-
ward hopefully to continued publication.
The date at the bottom of the page, 1861,
and a glance at American history give
testimony to the role the Civil War
played in the Society’s annals. In 186]
Charles Hovey, first secretary of the So-
ciety and head of Illinois State Normal
University, marched off to war as Colonel
of the Schoolmaster’s Regiment, taking
with him most of the men of the student
body and some of the faculty (Marshall
1956:75-6). No one knows how many
potential scientists died at Fort Donelson
and in other engagements, or how much
brain power from Illinois centers of learn-
ing was siphoned from the science of peace
into the science of war.
Two years after the Civil War was
over, biological science in Illinois re-
sumed its march, but the Natural His-
tory Society limped badly. It never re-
covered from the effects of the conflict.
However, in voting an appropriation to
the Natural History Society and estab-
lishing the State Entomologist’s Office
and the Illinois Industrial University, the
Illinois General Assembly (1867) gave
substantial evidence that the people of the
state wanted to continue the educational
movement that founders of the Society
had helped to start.
AYARS: PUBLICATIONS AND PUBLIC RELATIONS 205
Walsh’s first and only report as State
Entomologist was followed by the re-
ports of his successors: 4 by William Le
Baron, 6 by Cyrus Thomas, and 18 by
Forbes. Le Baron (1871) named his first
report the first report of the State Ento-
mologist. The reports were discontinued
when the State Entomologist’s Office was
merged with the Illinois State Labora-
tory of Natural History in 1917.
In 1876, about 4 years after his appoint-
ment as Curator of the Illinois Museum
of Natural History, Forbes issued the
first number of a technical series that has
come down through the years as the Bul-
letin. It has been known successively as
the Bulletin of the Illinois Museum of
Natural History, 1876; Bulletin of the
State Laboratory of Natural History,
1877 to the end of June, 1917: Bulletin
of the Illinois State Natural History Sur-
vey, July, 1917, to early 1932; and I1linois
Natural History Survey Bulletin, late
1932 to the present. Throughout its ex-
istence the Bulletin has reported the re-
sults of mature, original research. Most
of the articles have been slanted toward
technical workers in the biological sci-
ences.
Of wider interest are numbers of the
circular series. The emphasis in this se-
ries is on ““how-to-do’”—for example, how
to control diseases or insect pests of shade
trees. Directions in the circulars are
based on the best available information
and usually only to a limited extent on
original research by the writers. The lan-
guage of the circular series is less tech-
nical than that of the Bulletin.
The complete history of the circulars
is not known. ‘‘We have also issued sev-
eral entomological circulars not of any
series,” Forbes (1888:7) wrote 70 years
ago. ‘The modern circular series dates
from 1918 and a 6-page unnumbered pub-
lication titled ‘““The More Important In-
secticides and Repellents,” by W. P.
Flint. Between 1918 and 1930, 13 other
circulars (3 unnumbered and 10 num-
bered) were issued by the economic ento-
mologists, 4+ by the foresters, and 1 by the
botanist on the staff. Each circular was
issued as a product of the section repre-
sented by its author. In 1934 the circu-
lar series was reorganized and the early
circulars were numbered or renumbered.
206
The last circular published, I/linois Trees
and Shrubs: Their Insect Enemies, 1s
numbered 47. Some of the circulars have
been reprinted more than once, one of
them, that on insect collecting, five times.
Diverse in several ways are the articles
published in the Biological Notes series,
{PG Prairies
of Hlincis
Insect Enemies
A few of the circulars, articles of the Bulletin,
Illinois Natural History Survey.
the first of which was issued in Decem-
ber, 1933, in mimeographed form. Some
of the articles stand as progress reports
of extensive projects, later to be subjects
of articles in the Bulletin. Some are final
reports covering small projects. Some are
technical. Some emphasize “how-to-do”’
and in content and language are similar
to the circulars. They are on various
subjects and of various lengths. Early
articles in this series were mimeographed
and they contained no illustrations. Recent
articles have contained illustrations and
they have been planographed reproduc-
ILtiInois NATruRAL History SuRVEY BULLETIN
Vol. 27, Art. 2
tions of typewritten copy. The most re-
cent article of the Biological Notes is
No. 39.
The fourth of the series of publications
now issued by the Illinois Natural His-
tory Survey is the manual. Each number
is concerned with a single group of the
EeTOPana:
Sires
SOrTONTAN ease
i bee fla
Norther nef
A MECIACTL AR WATEEROWL MIGRATE
Ie 4 CRNTRAL NORTH AMERICA
j Fusarium Discase
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HUUNOIS pees
x Diseases
and biological notes issued recently by the
state flora or fauna, and each is designed
for use by young as well as mature nat-
uralists. The first of the manuals was
Fieldbook of Illinois Wild Flowers. It
was issued in 1936, is now out of print,
and is being revised. Three other man-
uals have been published, one on land
snails, one on native shrubs, and one on
mammals.
Preceding the manual series in time,
and somewhat similar in character, were
the now discontinued final reports, two
on birds and one on fishes (Ridgway
1889, 1895; Forbes & Richardson 1908).
ss
December, 1958
Other discontinued series were the Ex-
ecutive Reports of the State Laboratory
of Natural History, 1878-1916, and of
the State Entomologist, 1900-1915. Most
of these reports were published as pam-
phlets and were published also in Univer-
sity of Illinois reports or in Transactions
of the State Horticultural Society.
Annual reports made by the Natural
History Survey to the Illinois State De-
partment of Registration and Education
were begun in 1918 and have been con-
tinued to the present. hese reports have
been published by the Division or by other
administrative units of the state govern-
ment. Biennial reports have for many
years been included in the Blue Book of
the State of Illinois.
A considerable number of important
contributions by Illinois Natural History
Survey staff members have been published
in the bulletin and circular series of the
Illinois Agricultural Experiment Station.
Many sstaff-written articles covering
results of research have been published in
technical journals. In a biennial report
published 70 years ago, Forbes (1888:8)
listed about a dozen articles “written at
the Laboratory, but published elsewhere.”
In each of the past few years, approxi-
mately 80 articles written by staff mem-
bers of the Illinois Natural History Sur-
vey have appeared in publications other
than those issued by the Survey.
EDITORIAL PERSONNEL
That some editing was done on the
first papers published by the Illinois Nat-
ural History Society is evident from a
sentence in the Secretary’s Report pub-
lished with the Transactions for 1860
(Wilber 1861d:8): “ The following pa-
pers were prepared—most of them—for
the last meeting of the Society, and have
since been revised for publication in this
report.” The Preface indicates that Wil-
ber (1861d:3-4) was the Editor.
For many years Forbes himself did
considerable editing of the papers issued
by the agencies he headed. Until 1926
his principal editorial assistants were
Charles A. Hart and Miss Mary Jane
Snyder. “Mr. C. A. Hart, my efficient
secretary,” Forbes (1882a:8) wrote in an
early report, “is responsible for the cor-
AyARS: PUBLICATIONS AND PuBLic RELATIONS
207
respondence, for the preparation of pa-
pers for the press, the correction of proofs,
and other clerical service.” To the ‘‘effi-
cient secretary’ was soon assigned the
“labeling, determination, and arrange-
ment of the insect collections’ of the
State Laboratory (Forbes 1887:2). By
1896 he was listed as Systematic En-
tomologist and Curator of Collections
(Forbes 1896:2).
Miss Snyder joined the staff of the
State Laboratory of Natural History in
1883 and retired from the staff of the
Natural History Survey in 1925. She
died in 1938 at the age of 93 years. She
was listed successively as amanuensis,
stenographer, secretary, and editor and
proofreader. Apparently, as Hart’s ento-
mological activities increased, his editorial
duties were taken over by Miss Snyder.
A scientist who knew Miss Snyder well
characterized her recently as “an excellent
editor.” He added, “‘overcritical in a
way.” Good editors, like good scientists,
are apt to be “overcritical in a way.”
Tradition reports that Forbes was not
easily satisfied either with his own or his
assistants’ papers, that he was meticulous
about detail.
H. H. Chapman, Yale University staff
member who worked on forestry prob-
lems for the Natural History Survey dur-
ing the summers of 1922 and 1923, stated
recently that Forbes was accustomed ‘“‘to
revising the reports of his subordinates,
cutting them down to about one-fourth
of their original bulk” (letter of July 10,
1958, from H. H. Chapman to C. W.
Walters).
Successor to Miss Snyder in 1926 was
H. Carl Oesterling, who for 2 years, be-
fore he was appointed full-time Editor of
the Natural History Survey, was em-
ployed jointly by the Illinois Geological
Survey, Illinois Water Survey, and Nat-
ural History Survey. Oesterling had previ-
ously taught at the University of Illinois.
After Oéesterling went to the Univer-
sity of Illinois Press in 1931, Carroll B.
Chouinard was appointed to replace him.
Following Chouinard’s appointment, the
editorial office was called the Section of
Publications. Chouinard resigned in 1937
to go to Pennsylvania State College, and
James S. Ayars was appointed Editor. In
1947 the title of Editor was changed to
208
Technical Editor. In 1948 the Section
of Publications was renamed the Section
of Publications and Public Relations.
Until Mrs. Blanche Penrod Young
was appointed Assistant Technical Editor
in September, 1948, the editorial staff had
consisted of the Editor and temporary or
part-time assistants. In 1958 Mrs. Diana
Root Braverman was appointed as a sec-
ond Assistant Technical Editor.
For many years photographs for illus-
trating publications have been taken by
members of the technical staff. More
than 60 years ago, Forbes (1894:36)
mentioned in a biennial report “a dark
room for photography” among the rooms
available to the State Laboratory of Nat-
ural History.
Robert E. Hesselschwerdt was the
first person on the staff whose title in-
cluded the word photographer. He was
appointed Assistant Technical Photogra-
pher in 1946 and assigned to the Section
of Publications. Upon his resignation in
1948, he was replaced by Charles L.
Scott, who is now picture editor of the
Milwaukee Journal.
William E. Clark, the present staff
photographer, was appointed in April,
1951.
PUBLIC RELATIONS
Long before public relations in name
were added to Illinois Natural History
Survey activities, public relations in fact
were being practiced with consummate
skill. Forbes had a natural flair for pub-
lic speaking and for writing. He was
popular as a speaker before scientific, ag-
ricultural, and educational groups. His
articles on insects and other subjects
were welcomed by editors. In a biennial
report Forbes (1888:8) mentioned “a
considerable number of articles written
for the agricultural papers in response to
inquiries from their editors.”
His well-organized, stimulating, even
exciting reports of accomplishments by,
or plans for, the agencies he represented
were included as important parts of larger
reports by university presidents or other
administrators.
In recent years public relations media
have included principally news releases
(to press, radio, and television), educa-
ILtinois NaturAL History SurvEY BULLETIN
Vol. 27, Art. 2
tional motion pictures, photographs, and
magazine feature articles. Many public
contacts have been made each year by the
Chief and members of the staff in ad-
dressing groups of persons interested in
biological sciences and related subjects.
EDITORIAL POLICY
The scientific articles published by the
founding fathers of the Illinois Natural
History Survey and by Forbes and his
contemporaries set standards of excel-
lence that have served as a tradition and
a challenge to subsequent members of the
staff. Through the years, exactness of re-
search and quality of the published re-
ports based on research have been given
precedence over quantity of research and
speed of publication. Most of the organi-
zation’s reports that stand as landmarks
in biological literature were several years
in the making. Extreme examples are
some of the reports on the extensive bird
studies made in 1905-1909; the last of
the reports on these studies was not pub-
lished until 1923 (Forbes 19075, 1908,
1913; Forbes & Gross 1921, 1922, 1923).
Even 70 or more years ago, when print-
ing and engraving processes were less ef-
ficient than now, Forbes laid great stress
on adequate illustrations. His policy with
respect to adequate illustrations has been
continued, and with improvement in
printing and engraving processes have
come changes in illustration practices that
have added to the convenience of readers.
Instead of grouping illustrations at the
end of an article, as Forbes was sometimes
forced to do, recent editors have been able
to place each illustration close to its prin-
cipal text reference.
In the writing and editing of reports
designed for publication is still felt the
influence of the founding fathers, the
classicists who sought to broaden the
base of education. Respect for words is
combined with respect for persons, the po-
tential readers.
Editorial problems have not been so
simple in the past half century as when
Wilber (1861d:3) wrote that “the sub-
jects have generally been treated in a pop-
ular rather than a technical style.” The
wide range of subject matter and the di-
versity of interests of the various reader
December, 1958
groups served by the Natural History
Survey have made necessary a diversity of
style and even of format. Each report to
be published is written and edited for a
particular reader group in the hope that
to this group the report will be “immedi-
ately useful and interesting.”
The joint aim of the writer, or writers,
and the editorial staff is to make each
published paper an orderly, logical presen-
Ayars: PUBLICATIONS AND PuBLIC RELATIONS 209
tation of the results of a particular seg-
ment of research; to include all pertinent
data and to exclude all inconsequential
or extraneous matter; to achieve accu-
racy in original data and in quoted and
paraphrased material; to state only such
conclusions as can be justified by data
presented; to make all statements so clear
that they can be easily understood and
cannot readily be misunderstood.
Library
HEN Cyrus Thomas proposed a
Natural History Society of Illinois
in 1857, his plan provided for the de-
velopment of a library. In the letter out-
lining his plan, we find this statement:
“That such works as can be collected by
gift, which will be useful in the investiga-
tion of Natural History and relate there-
to, be gathered by the members to form
a library” (Bateman 1858a:12).
While the Natural History Society
was in the process of organization, Dr.
E. R. Roe of Bloomington reported for the
Committee on Library (Wilber 186ld:
12): “That it shall contain all available
works on the Natural Sciences, Home
and Foreign Surveys, Manuals, Works of
Reference in the several departments,
Miscellaneous Works, not strictly scien-
tific, Maps and Charts, etc.”
THE LIBRARY AT NORMAL
When the Society received its charter
from the state legislature in 1861, a li-
brary was provided for in Section 3
(Wilber 1861d:15):
Said natural history society shall also pro-
vide for a library of scientific works, reports
of home and foreign surveys, manuals, maps,
charts, etc., etc., such as may be useful in
determining the fauna and flora of Illinois,
and said library shall be kept in the museum
of said society at the State Normal University.
This library, while it was still at I]li-
nois State Normal University, Normal,
was transferred to the Illinois State Lab-
oratory of Natural History when the
Laboratory was created in 1877.
The library served not only the mem-
bers of the Natural History Society and
the State Laboratory; it was used by
naturalists located in other parts of the
state. In the report for 1879-1880 (Forbes
1880f : 9-20), a classified list of more than
300 titles of the principal works added
during that period was included. This list
was for the “benefit of the students of
natural science throughout the State”
and included works on mammals, birds,
RUTH RR WARRIGw
reptiles, fishes, insects, plants, and mis-
cellaneous biological subjects.
THE LIBRARY AT URBANA
In 1885, when Forbes accepted the
position of Professor of Zoology and En-
tomology at Illinois Industrial Univer-
sity (soon to become the University of
Illinois), he made the request that the
property of the State Laboratory of Nat-
ural History be transferred to this Uni-
versity (Burrill 1887a:10-1). “The es-
sentials of my original work and of the
State natural history survey can be trans-
ferred from the Normal building to the
basement of the University without
detriment to any part of the work of the
Normal School, . . .” The property
transferred included the library (Burrill
1887a:101).
A special project of the State Labora-
tory of Natural History in 1893 was an
exhibit of the zoology of Illinois at the
Columbian Exposition, held in Chicago.
This exhibit included a section of the
library, ‘“‘the books selected being mainly
entomological, and including serial publi-
cations, periodicals, monographs, reference
books, pamphlets, etc., to the number of
about five hundred volumes” (Forbes
1894:7).
When the biological station was estab-
lished near Havana in 1894, the libraries
of the University and of the Laboratory
supplied a working library of about 120
volumes (Forbes 1894:3, 19).
The floating laboratory, launched in
April, 1896, had a cabin that at one end
housed an office and library, 11 feet, 6
inches by 16 feet. A 24-page illustrated
pamphlet describing the biological sta-
tion contained the information that to
summer students doing research ‘access
will be given to the biological library of
the Station. Books will also be loaned, as
needed, from the library of the State Labo-
ratory of Natural History and from that
of the University of Illinois” (Forbes
1896:16, 26-7).
[ 210 ]
December, 1958
The library remained in the possession
of the State Laboratory of Natural His-
tory and its successor, the State Natural
History Survey, until 1928, when it was
turned over to the University of Illinois
Library (Cunningham 1928:275-6).
This transfer was made with the follow-
ing stipulations:
1. That each article now belonging to the
library of the Natural History Survey or
added to it hereafter shall bear a distinctive
mark;
2. That such additions shall be made to
it, from time to time, as are necessary to
the work of the Natural History Survey as
certified by the Chief thereof and approved
by the President of the University; and
3. That the scientific staff of the Natural
History Survey shall have at all times a prior
right to the use of books, pamphlets, and
papers of the aforesaid library, their use by
members of the faculty and by the students
of the University being second to this claim.
When the Natural History Building
was completed, the library moved to the
rooms assigned to it (Forbes 1894:35-6).
Since my last report to you the State Labora-
tory has removed to the rooms assigned to
it in the new Natural History Hall of the
University of Illinois, five on the first floor
and two in the basement. These rooms are
a Director’s office, 21 ft.x19 ft., a library room
7115 i Ra
Provision was again made for a sepa-
rate library when the Natural Resources
Building was planned. Plans for trans-
ferring the book collection from the Nat-
ural History Building to the Natural
Resources Building were being considered
as early as July, 1939. A letter dated
July 26, 1939, from Dr. P. L. Windsor,
Director of University Libraries, to Dr.
T. H. Frison, Chief of the Natural His-
tory Survey, contained this statement:
I am beginning to think of the preparations
that will have to be made when the State
Survey building is completed and you take
over with you, such parts of the Natural His-
tory Library as you think are necessary for
your current work.
After much planning and working out
of policies, an agreement between the Nat-
ural History Survey and the University
was reached. This agreement was out-
lined in a letter dated January 22, 1941,
from Dr. Carl M. White, then Director
of University Libraries, to Dr. Frison, as
follows:
WARRICK:
LIBRARY 211
(1) The University is to catalog all books,
journals, etc., including arrears and recata-
loging.
(2) The University is to provide in the
regular library budget a fund for the pur-
chase of books for the Natural History Sur-
vey (at present $400).
(3) The University is to manage the Nat-
ural History Survey Library the same as
other departmental libraries, including provi-
sion of service to the Natural History Survey
from other libraries on the campus. The pro-
fessional staff of the Survey is to receive
service from the various libraries on the
campus on the same basis as the faculty of
the University.
(4) The University is to allow the Natural
History Survey “preferred use” of the ma-
terial in the Natural History Survey Library
as “preferred use” is defined in your letter
to me of December 16.
(5) The University is to provide, besides
general supervision, the sum of $700 in 1940-
41 for staff in the Natural History Survey
Library.
It is to provide $1500 for each year of
the biennium 1941-43.
(6) The Natural History Survey is to pro-
vide housing for such books as need to be
housed in the Natural Resources Building.
(7) The Survey is to relieve the University
September 1, 1943, of the responsibility for
providing staff for library service.
The Natural History Survey Library,
opened as a separate unit in September,
1940 (Lill 1942:1), was located on the
fourth floor of the Natural Resources
Building, and remained in that location
until the west wing of the Natural Re-
sources Building was completed. In Feb-
ruary, 1952 (Simmons 1952:1), the li-
brary was moved to its permanent loca-
tion on the first floor at the south end of
the west wing.
LIBRARY COLLECTIONS
In a paper, “Natural History in
Schools,” which was read before the IIli-
nois State Teachers’ Association in 1860,
A. M. Gow of Dixon gave a brief his-
tory of the Illinois Natural History So-
ciety and stated that its library at that
time contained 300 volumes (Gow 1861:
96).
Professor Forbes in his 1881-1882 re-
port stated that additions to the library
since his last report had been 360 vol-
umes and 200 pamphlets, many of them
“rare and costly works—the foundation
stones of zoological and botanical litera-
ture’ (Forbes 1882a:7). He wrote that
212 Ittinois NarurAL History Survey BULLETIN
“particular attention has been paid to
cataloguing, and this has been kept fully
abreast of the additions. A card catalogue
of authors is now absolutely complete to
date, and a subject catalogue is well
under way.”
In 1885, when the State Laboratory
of Natural History was transferred from
Illinois State Normal University to the
University of Illinois at Urbana, the li-
brary had a collection of 1,207 bound
volumes and 3,856 pamphlets and period-
icals (Burrill 1887a:101). The library
additions in 1899-1900 were 648 volumes
and 764 pamphlets (Forbes 1901:11).
Professor Forbes in 1909 stated that the
library then had nearly 7,000 books and
something over 17,000 pamphlets (Forbes
1909 :55-6).
The library at present contains over
19,000 volumes and approximately 5,000
pamphlets, the greater part being period-
icals and other serials. The field of en-
tomology is represented most strongly in
the collection, but other subjects, such as
Vol. 27, Art. 2
zoology, botany, wildlife, and conserva-
tion, are emphasized.
For many years, the library has added
to its collection by exchanging the publi-
cations of the State Laboratory of Nat-
ural History and the Natural History
Survey with other institutions. The policy
toward exchanges was expressed by Mr.
Gow (1861:96) nearly 100 years ago:
“The library of the Society will embrace
everything that can be procured by gift,
purchase or exchange, upon Natural His-
tory in particular, and Science in general.”
As the number of publications of the
State Laboratory increased, the library
was able to establish a larger number of
exchanges, especially with European so-
cieties and institutions (Forbes 1901:10).
We are now receiving in exchange for our
State Laboratory Bulletin one hundred and
eighty-one periodical scientific publications,
of which fifty-nine are American, twenty-
eight are British or British-colonial, twenty-
six are German, sixteen French, twelve Ital-
ian, and the remaining forty are Russian,
Swedish, Norwegian, Danish, Dutch, Hun-
v
Part of the Illinois Natural History Survey library in the Natural Resources Building. This
library is noted especially for its large collection of bound volumes of periodicals in the bio-
logical sciences.
December, 1958
garian, Portugese, Egyptian, South American,
and Japanese.
At the present time the library has an
exchange arrangement with approximately
500 scientific institutions and societies, a
large number of which are foreign.
LIBRARY PERSONNEL
Provision for the care of the library
has been made from the beginning of the
Natural History Society to the present
time. The person in charge of the library
has always had the title /ibrarian and
has been a member of the staff, first of
the Natural History Society (Wilber
1861d:10) and later a member of the
staff of each of the state agencies that fol-
lowed, except for a period from 1928
(Cunningham 1928:275) to 1943 when
the University of Illinois assumed full
responsibility for the book collection.
The first librarian was Ira Moore,
instructor in mathematics at Illinois State
Normal University (Wilber 1861d:10;
Hovey 1859:401). His duties were def-
initely stated in the Report of Committee
on Library (Wilber 1861d:12):
It shall be the duty of the Librarian to
arrange the books of the Society, to make and
keep a catalogue of the same, to keep a rec-
ord of the books drawn from the library as
directed by the Society, and report to the
Society at its annual meeting.
In a report to the Regent of the Uni-
versity of Illinois in 1886, Professor
Forbes mentioned a librarian among the
personnel of the State Laboratory (Bur-
rill 1887a:101). Henry Clinton Forbes
served as Librarian and Business Agent
of the Laboratory from 1892 to 1902
(Pillsbury 1892:284; 1894:135; 1896:
[14]; 1898:[15]; 1901:xvir; 1902:xx).
The policy of appointing professional
librarians was started in 1906 with the
appointment of Miss Edna Lucy Goss,
B.L.S. (Pillsbury 1906:xxm) and has
continued to the present.
FINANCIAL SUPPORT
Financial support for the library has
always been considered of great import-
ance. It was considered important even
before the Illinois Natural History So-
ciety became a chartered organization. In
WARRICK:
LIBRARY 213
the Report of Committee on Library, the
following provision for a library was
made (Wilber 1861d:12) : “That the So-
ciety devote all moneys obtained by do-
nations and memberships to this import-
ant object [library], except so much as
are necessary for expenses.”’
In an early report of the Director of
the State Laboratory of Natural History,
a plea was made for a public scientific
library (Forbes 18785:5-6) :
A most indispensable requisite for thorough
work in any direction is an increase of the
Library. Much of the time and money al-
ready invested in the Laboratory collections
and belongings must lie idle until this im-
provement is made. There is not anywhere
within reach of our naturalists a_ scientific
library sufficient to assist them to reliable
original work in any department of natural
history. Nothing which the State could do for
science would so stimulate a productive ac-
tivity among them as a moderate appropria-
tion for a public scientific library; and there
is evidently no place where this library may
be so properly built up as in connection
with the State Laboratory of Natural His-
tory. I have therefore included the sum of
$2,000 for this purpose in my estimates, and
the further sum of $200 for the services of
a Librarian, to catalogue and thoroughly or-
ganize the accessions on the plan already in
use. This plan of organization place[s] the re-
sources of the library at the ready command
of the investigator, without requiring that com-
plete previous acquaintance with the litera-
ture of his subject which he can gain only by
long use of a large library. It is proposed
to use the money which may be voted for
library purposes, first of all to procure those
books now actually needed by our Illinois
naturalists for the successful prosecution of
the original investigations upon which they
are at present engaged, and to provide for’
the future only when these present pressing
needs have been supplied.
The state legislature granted part of
the appropriation requested by Professor
Forbes. In a subsequent report he made
a statement concerning the value of the
library (Forbes 1880f:9) :
No expenditure made by the Laboratory
during the last two years has been so im-
mediately profitable, both to the work of the
establishment and to the studies of other
naturalists, as that made for new _ books.
While the additions are very few compared
with the literature needed, they have cleared
the field of difficulties which have blocked the
progress of our work for years, and have first
made possible to the students of our local
natural history, original work of a satisfac-
tory character, in a few departments of
zoology and botany.
214
The library received its support from
appropriations made by the state legisla-
ture to the State Laboratory or Natural
History Survey until the books were
transferred to the University of Illinois,
at which time the University assumed
the responsibility for the book collection
(Cunningham 1928 :275-6).
After 100 years of library service to
the staff and to the naturalists of the
Ittinots NarurAL History Survey BULLETIN
world ..
Vol. 27, Art. 2—
state, we hope that a statement made by |
Professor Forbes a half century ago is —
still true and that the library will always |
maintain the high standard set for it by
its founders. “Apart from its collections,
. the most useful possession of the
Paborsints is its library, which is the —
product of many years of careful selection
and purchase of the literature of the
.” (Forbes 1909:55).
Former Technical Employees
Illinois Natural History Society, Illinois State
Entomologist’s Office, Illinois State Museum of Natural
History, Illinois State Laboratory of Natural History,
Illinois Natural History Survey
OLLOWING is a partial list of for-
mer employees of the Illinois Natural
History Society (1858-1871), Illinois
State Entomologist’s Office (1867-1917),
Illinois State Museum of Natural His-
tory (1871-1877), Illinois State Labora-
tory of Natural History (1877-1917),
and Illinois Natural History Survey
(since 1917). The list is not complete be-
cause early records are fragmentary or do
not exist, and because, for the sake of brev-
ity, it seemed desirable to omit the names
of many short-term or part-time em-
ployees. A number of collaborators who
worked closely with regular staff members
are not listed, although they made contri-
butions to the official publications. Because
ADAMS, CHARLES CHRISTOPHER
Entomologist, 1896-1898
ADAMS, LEVERETT ALLEN
Zoologist, 1929
ALEXANDER, CHARLES PAUL
Entomologist, 1919-1922
ALEXOPOULOS, CONSTANTINE J.
Botanist, 1930-1931
Ames, RALPH WOLFLEY
Plant Pathologist, 1951-1952
ANDERSON, HArry WARREN
Botanist, 1922
ANDERSON, JOHN M.
Biologist, 1939-1941
APPLE, JAMES WILBUR
Entomologist, 1943-1949
AUDEN, KENNETH FRANCIS
Entomologist, 1925-1927
BAKER, FRANK COLLINS
Zoologist, 1931-1932
BALDUF, WALTER VALENTINE
Entomologist, 1923
BARNICKOL, PAUL GEORGE
Aquatic Biologist, 1945-1948
Barrett, E. G.
Botanist, 1931-1932
Braco, ALICE MARIE
Entomologist, 1899-1900
BESS LE: 8. Eb As T
of their important contributions to the
work of the Natural History Society and
the maintenance of its collections, the
names of two early curators, C. D. Wilber
(1858-1864) and Joseph A. Sewall
(1864-1867), and of the first librarian,
Ira Moore (1858-1863), have been in-
cluded; all three were members of the
staff of Illinois State Normal University.
The first official employee whose sal-
ary was paid from funds appropriated by
the state legislature for that purpose was
John Wesley Powell, appointed Curator
in 1867. From this beginning, the staff
has increased to its present total of 101.
No present employees are included in the
following list.
BERGER, BERNARD GEORGE
Entomologist, 1941-1945
BETTEN, CORNELIUS
Entomologist, 1931
Brown, FRANK ARTHUR
Zoologist, 1935
Burks, BARNARD De Witt
Entomologist, 1937-1949
BurriL__, THOMAS JONATHAN
Botanist, 1885-1892
BuTLER, Cyrus W.
Biologist, 1880-1882
CAMPANA, RICHARD JOHN
Plant Pathologist, 1952-1958
CAMPBELL, LEO
Botanist, 1930-1931
CHANDLER, STEWART CURTIS
Entomologist, 1917-1957
CHAPMAN, HERMAN HAuvupT
Forester, 1922-1923
CHASE, ELIZABETH BROWN
Biologist, 1945-1948
CHOUINARD, CARROLL BENEDICT
Editor, 1931-1937
CoMPTON, CHARLES CHALMER
Entomologist, 1921-1944
CoQuUILLETT, DANIEL WILLIAM
Entomologist, 1881
[ 215]
216
Cralc, WALLACE
Aquatic Biologist, 1898-1899
CRAWLEY, HENRI DouGLAs
Forester, 1950-1951
CREAGER, Don BAXTER
Plant Pathologist, 1939-1943
CuLVER, LAwson BLAINE
Forester, 1947-1954
DANIELS, Eve
Botanist, 1924-1926
Davis, JAMES ELwoop
Forester, 1935-1947
Davis, JOHN JUNE
Entomologist, 1907-1911
DeCourseEy, JOHN D.
Entomologist, 1929-1932
DeELonc, Dwicut Moore
Entomologist, 1934-1936, 1938, 1941,
1945
Dozier, HERBERT LAWRENCE
Entomologist, 1932
Driver, ERNEST CHARLES
Zoologist, 1930
Duccar, BENJAMIN MINGE
Botanist, 1895-1896
DuRHAM, LEONARD
Aquatic Biologist, 1947-1950
EARLE, FRANKLIN SUMNER
Mycologist, 1886
Eppy, SAMUEL
Botanist, 1925-1929
ELDER, WILLIAM HANNA
Game Specialist, 1941-1943
ENGELHARD, ARTHUR WILLIAM
Plant Pathologist, 1955-1956
FarrArR, MILTon Dyer
Entomologist, 1931-1946
FELL, RACHEL M.
Botanist, 1881-1882
Ferris, JOHN MAson
Plant Pathologist, 1957-1958
Fisk, VERNON C.,
Forester, 1921-1923
FLINT, WESLEY PILLSBURY
Entomologist, 1907-1943
ForsBeEs, ErNEST BROWNING
Zoologist, 1894-1896, 1899-1901
Forspes, HENry CLINTON
Librarian, 1894-1902
ForsBes, STEPHEN ALFRED
Curator, State Museum of Natural
History, 1872-1877 ; Director, State
Laboratory of Natural History,
1877-1917; State Entomologist,
1882-1917; Chief, Natural History
Survey, 1917-1930
Ittrnois NarurAL Hisrory Survey BULLETIN
Vol. 27, Arte 2
Foster, T. DALE
Zoologist, 1931-1932
FRENCH, GEORGE HAZEN
Entomologist, 1877-1878
Frison, (THEODORE HENRY
Entomologist, 1923-1930; Chief,
Natural History Survey, 1930-1945
GARMAN, PHILIP
Entomologist, 1914
GarRMAN, W. Harrison
Zoologist, 1877-1889
GIRAULT, ALECANDRE ARSENE
Entomologist, 1908-1911
GLascow, Ropert DouGLAss
Entomologist, 1905-1909, 1912-1915,
1927
GLENN, PressLEY ADAMS
Entomologist, 1911-1917
GopING, FREDERICK WEBSTER
Entomologist, 1885
GorF, CarLos CLYDE
Entomologist, 1927-1930
Goss, Epna Lucy
Librarian, 1906-1908
Gross, ALFRED OTTo
Ornithologist, 1906-1907, 1909, 1912
HANKINSON, THOMAS LEROY
Zoologist, 1911
Harris, HUBERT ANDREW
Botanist, 1930-1933
Hart, CHARLES ARTHUR
Entomologist, 1880-1918
Hart, Lypta Moore
Artist, 1891-1898
HaAwkKINsS, ARTHUR STUART
Game Specialist, 1938-1945
Hayes, WILLIAM PaTRICK
Entomologist, 1926, 1928-1934
HeEMPEL, ADOLPH
Zoologist, 1894-1896
HESSELSCHWERDT, ROBERT EDWARD
Zoologist, 1936-1942; Photographer,
1946-1948
HoFFMAN, PAUL FREDRICK, JR.
Plant Pathologist, 1951-1954
Hoop, JosEpH DouGLaAs
Entomologist, 1910-1912
Hortres, FREDERICK CHARLES
Entomologist, 1928-1930
Hunt, Francis D.
Aquatic Assistant, 1925-1937
Hunt, THOMAS ForsyTH
Entomologist, 1885-1886
HutTcHENS, LYNN HENRY
Aquatic Biologist, 1936-1938,
1946-1947
December, 1958
JANVRIN, CHARLES EDWIN
Librarian, 1912-1929
JoHNSON, WILLIS GRANT
Entomologist, 1894-1896
JORDAN, JAMES SCHUYLER
Game Specialist, 1948-1955
KAHL, Huco
Entomologist, 1892-1894, 1901-1902
KELLEY, GRACE Oscoop
Librarian, 1908-1912
KNAB, FREDERICK
Artist, 1903-1905
KNIGHT, HARryY HAZELTON
Entomologist, 1930, 1932-1933, 1937
KNIGHT, KENNETH LEE
Entomologist, 1938-1939
Korom, CHARLES ATWOOD
Aquatic Biologist, 1895-1900
KRUMHOLZ, Louis A.
Zoologist, 1938-1941
Kupo, RicHarp R.
Zoologist, 1930
LarGcE, ‘THOMAS
Aquatic Biologist, 1899-1902
Le Baron, WILLIAM
Entomologist, 1870-1875
LEIGH, WALTER HENRY
Game Specialist, 1935-1938
Low, Jessop BUDGE
Game Specialist, 1941-1943
Luce, WILBUR MARSHALL
Zoologist, 1929-1930, 1932
LuUETH, FRANCIS X.
Zoologist, 1939-1940
McCauL.ey, WILLIAM EpWARD
Entomologist, 1934-1941
McCiure, Howe EL tiorr
Entomologist, 1930-1933
McCormick, A. K.
Aquatic Biologist, 1881-1882
McDouGaL_, WALTER BYRON
Botanist, 1928
MAaLiocH, JOHN RUSSELL
Entomologist, 1913-1921
Matty, FREDERICK WILLIAM
Entomologist, 1889-1890
Matrsy, Cora M.
Librarian, 1885—1886
MarTEN, JOHN
Entomologist, 1888—1894
Mippteton, Netrie
Entomologist, 1878—1880
MiLier, AuGust Epwarp
Entomologist, 1926-1928
Mier, Ross JEWELL
Forester, 1947-1956
East: ForMER TECHNICAL EMPLOYEES
MILNER, ANGE V.
Librarian, 1880-1882
Moore, [RA
Librarian, 1858-1863
Moore, THomAs EpwINn
Entomologist, 1948-1956
NYBERG, FLORENCE ANNA
Assistant to the Chief, 1922—1945
O’DonNELL, DoNALD JOHN
Zoologist, 1931-1937
OkrSTERLING, H. Cari
Editor, 1926-1931
PEAKE, CHARLEs O.
Botanist, 1921-1923
Peirce, ALAN STANLEY
Botanist, 1933-1934
PrEPOON, HERMAN S.
Botanist, 1931-1933
PLUNKETT, Orpa ALLEN
Botanist, 1922
Porter, CHARLES LYMAN
Botanist, 1921-1922
PowWELL, JOHN WESLEY
Curator, 1867-1872
Powers, Epwin Booty
Entomologist, 1917
RASMUSSEN, DANIEL IRVIN
Biologist, 1931-1932
RICHARDS, WILLIAM RoBIN
Entomologist, 1950-1953
RICHARDSON, RoBert Ear
Aquatic Biologist, 1903-1904,
1909-1933
RIEGEL, GARLAND TAVNER
Entomologist, 1938-1942
Rres, DONALD TIMMERMAN
Naturalist, 1938
ROBERTSON, WILLIAM BECKWITH, JR.
Game Specialist, 1952-1956
SAWYER, LeEsLig EDWIN
Forester, 1929-1935
SCHNEIDER, IRVING ROBERT
Plant Pathologist, 1954-1956
SCHOPF, JAMES
Botanist, 1931
SCHREEDER, W. F.
Forester, 1921-1925
ScoTT, CHARLES L.
Photographer, 1948-1951
SELANDER, RICHARD B.
Entomologist, 1955—1958
SEWALL, JOSEPH A.
Curator, 1864-1867
SEYMOUR, ARTHUR BLIss
Botanist, 1881-1883, 1884, 1886
217
218 Ittinois NaruraAL History SurvEY BULLETIN
SHELFORD, Victor ERNEST
Ecologist, 1914-1927
SHOEMAKER, Hurst
Zoologist, 1942, 1944
SHROPSHIRE, LESLIE HAROLD
Entomologist, 1931-1942
Srmmons, LILLIAN MARGUERITE
Librarian, 1943-1952
SMITH, Dora
Biologist, 1894
SMITH, EMMaA A.
Entomologist, 1877
SMITH, FRANK
Zoologist, 1894-1897, 1907-1910
SmitH, LINDLEY MALCOLM
Entomologist, 1907-1917
Snow, Francis HUNTINGTON
Entomologist, 1892
SNYDER, Mary JANE
Amanuensis and Editor, 1883-1925
SOMMERMAN, KATHRYN MARTHA
Entomologist, 1939-1946
Sowts, Lyte K.
Game Specialist, 1940-1941
SPOONER, CHARLES 5S.
Entomologist, 1917-1920
SPOONER, CHARLES 5., JR.
Biologist, 1939-1942
STANLEY, WILLARD FRANCIS
Zoologist, 1935
Stout, GILBERT LEONIDAS
Botanist, 1926-1930
SUMMERS, HENRY ELIJA
Entomologist, 1892-1893
SURANY, PAUL
Entomologist, 1950-1955
SuRFACE, HArvey ADAM
Zoologist, 1899
‘TANQUARY, Maurice COLE
Entomologist, 1910-1912
‘Taytor, Estes PARK
Entomologist, 1903-1905
TEHON, Leo Roy
Botanist, 1921-1954; Acting Chief,
Natural History Survey, 1945-1946
LT EErorD; C.J.
Forester, 1921-1929
‘THOMAs, Cyrus
Entomologist, 1875-1882
THompson, Davin Hiram
Zoologist, 1923-1944
Tirus, EpwArp SHARP GAIGE
Entomologist, 1902-1903
‘TOWNSEND, LEE HILL
Entomologist, 1932-1936
‘TRUMBOWER, JOHN ABBOTT
Botanist, 1932-1933
VAN CLEAVE, HARLEY JONES
Parasitologist, 1911-1912
. Vasey, GEORGE W.
Acting Curator, 1871-1872
VestTaAL, ARTHUR GIBSON
Botanist, 1909
Von LIMBACH, BRUNO
Zoologist, 1940-1945
Wap Ley, FrANcis MARION
Entomologist, 1920
WALSH, BENJAMIN D.
Entomologist, 1867-1869
WANDELL, WILLET NORBERT
Forester, 1945-1954
WEBSTER, FRANCIS MARION
Entomologist, 1881-1884,
1902-1904
WeEeEbD, CLARENCE Moores
Entomologist, 1885-1888
WEINMAN, CarRL JOHN
Entomologist, 1937-1952
West, JAMES ALEXANDER
Entomologist, 1905-1908
Wiper, C. D.
Curator, 1858-1864
Wo Lr, JOHN
Botanist, 1880
Woop, FRANK ELMER
Aquatic Biologist, 1905-1909
WoopwortH, C. W.
Entomologist, 1884-1886
WriGcHt, JOHN McMaster
Entomologist, 1943-1957
YEAGER, LEE EMMETT
Forester, 1938-1945
YouNG, PAUL ALLEN
Botanist, 1922-1925
Yuasa, HACHIRO
Entomologist, 1921-1922
ZETEK, JAMES
Entomologist, 1909-1911
ZUCKERMAN, Bert MERTON
Plant Pathologist, 1951-1954
Vol. 27, Art. 2
PLEA TORE. Cit BD
Agassiz, Louis
1863. Methods of study in natural history.
Ticknor & Fields, Boston. viiit319
pp-
Alexander, Charles P.
1925. An entomological survey of the Salt
Fork of the Vermilion River in 1921,
with a bibliography of aquatic in-
sects. Ill. Nat. Hist. Surv. Bul.
15(8) :439-535.
Anonymous
1860. The anniversary week at Blooming-
ton. The agricultural convention;
annual meeting of the Illinois Nat-
ural History Society, and commence-
ment exercises of the State Normal
University. Chiefly compiled from
the reports of the Chicago Press and
Tribune and Chicago Times, Chi-
cago. 67 pp.
Professor S. A. Forbes, dies after
more than 60 years of service to the
University and State. Ill. Alumni
News 8(7) :278-82.
Fieldbook of Illinois wild flowers.
Ill. Nat. Hist. Surv. Man. 1. x+406
pp.
Ayars, James S.
1956. Leo Roy Tehon, 1895-1954. Ill. Acad.
Sci. Trans. for 1955, 48:224—5.
Babcock, H. H.
1930.
1936.
1872. The flora of Chicago and vicinity.
The Lens 1(1):20-6; 1(2):65-71;
1(3) 144-50; 1(4) :218-22.
Baker, Frank Collins
1906. A catalogue of the Mollusca of Illi-
nois. Ill. Lab. Nat. Hist. Bul. 7(6):
53-136.
Fieldbook of Illinois land snails. III.
Nat. Hist. Surv. Man. 2. 166 pp.
Balham, Ronald W., and Wm. H. Elder
1953. Colored leg bands for waterfowl.
Jour. Wildlife Mgt. 17(4) :446-9.
Bannister, Henry M.
1868. Geology of Cook County. Pp. 239-56
in Vol. III, Geological Survey of
Illinois, A. H. Worthen, Director.
Springfield, Illinois.
Barnard, W. S.
1880. Notes on the development of a black-
fly (Simulium) common in the rapids
around Ithaca, N. Y. Am. Ent., n.s.,
1(8) :191-3.
Barney, R. L.
1924. A confirmation of Borodin’s scale
method of age determination of Con-
necticut River shad. Am. Fish. Soc.
Trans. for 1924, 54:168-77.
Barnickol, Paul G., and William C. Starrett
1951. Commercial and sport fishes of the
Mississippi River between Caruth-
ersville, Missouri, and Dubuque,
Iowa. Ill. Nat. Hist. Surv. Bul.
25 (5) :267-350.
1939.
Bartlett, S. P., Secretary
1893. Report of the Commissioners. III.
Fish Commrs. Rep. 1890-1892. 52 pp.
Bateman, Newton, Editor
1858a. The meeting at Decatur. Il]. Teacher
4(1) :1-25.
1858. Natural History Society. Ill. Teacher
4(8) :258-9.
Bateman, Newton, Secretary
1867. Proceedings of the Board of Educa-
tion of the State of Illinois (Decem-
ber 19, 1866; March 26, 1867). Pe-
oria. 12 pp.
Proceedings of the Board of Educa-
tion of the State of Illinois (June 28,
29, 1871). Peoria. 20 pp.
Proceedings of the Board of Educa-
tion of the State of Illinois (June 26,
1872). Peoria. 12 pp.
Bayless, Mrs. Anne Douglas
1871.
1872.
1957. The annual meeting—1957. Ill. Au-
dubon Soc. Bul. 1957(102) :1-4.
Bebb, M. S.
1859. List of plants occurring in the north-
ern counties of the state of Illinois,
in addition to the catalogue given by
Dr. J. [sic] A. Lapham. Ill. Ag. Soc.
Trans. for 1857-1858, 3:586-7.
Beck, Lewis C.
1826a. Contributions towards the botany of
the states of Illinois and Missouri.
Am. Jour. Sci. and Arts 10(2) :257-
64.
1826. Contributions towards the botany of
the states of Illinois and Missouri.
Am. Jour. Sci. and Arts 11(1) :167-
82.
Contributions towards the botany of
the states of Illinois and Missouri.
Am. Jour. Sci. and Arts 14(1) :112-
21.
Bellrose, Frank C.
1940. Quail and pheasant studies in an
orchard county. Ill. Nat. Hist. Surv.
Biol. Notes 13. 11 pp.
Duck food plants of the
River valley. Ill. Nat. Hist.
Bul. 21(8) :237-80.
Duck populations and kill: an evalu-
ation of some waterfowl regulations
in Illinois. Ill. Nat. Hist. Surv. Bul.
23\(2)) 2327-72.
Relative values of drained and un-
drained bottomland in Illinois. Jour.
Wildlife Mgt. 9(3) :161-82.
The relationship of muskrat popula-
tions to various marsh and aquatic
plants. Jour. Wildlife Mgt. 14(3):
299-315.
1953a. Housing for wood ducks. IIl.
Hist. Surv. Circ. 45. 47 pp.
1953b. A preliminary evaluation of cripple
losses in waterfowl. N. Am. Wild-
life Conf. Trans. 18:337-60.
1828.
Illinois
Surv.
1941.
1944.
1945.
1950.
Nat.
[219]
220 I-tinors NaturAt History SurvEY BULLETIN
1954. The value of waterfowl refuges in
Illinois. Jour. Wildlife Mgt. 18(2):
160-9.
A spectacular waterfowl migration
through central North America. Ill,
Nat. Hist. Surv. Biol. Notes 36. 24
1957.
Pp.
1958a. The orientation of displaced water-
fowl in migration. Wilson Bul.
70(1) :20-40.
1958b. Celestial orientation by wild mal-
lards. Bird-Banding 29(2) :75-90.
Lead poisoning as a mortality factor
in waterfowl populations. Ill. Nat.
Hist. Surv. Bul. 27(3). In press.
Bellrose, Frank C., and Harry G. Anderson
1943. Preferential rating of duck food
plants. Ill. Nat. Hist. Surv. Bul.
22(5) :417-33.
Bellrose, Frank C., and Louis G. Brown
1941. The effect of fluctuating water levels
on the muskrat population of the
Illinois River valley. Jour. Wildlife
Mgt. 5(2) :206-12.
Bellrose, Frank C., and Elizabeth Brown
Chase
1950.
1959.
Population losses in the mallard,
black duck, and blue-winged teal.
Ill. Nat. Hist. Surv. Biol. Notes 22.
27 pp.
Bellrose, Frank C., and Jessop B. Low
1943. The influence of flood and low water
levels on the survival of muskrats.
Jour. Mammal. 24(2) :173-88.
Bellrose, Frank C., and Clair T. Rollings
1949. Wildlife and fishery values of bot-
tomland lakes in Illinois. Ill. Nat.
Hist. Surv. Biol. Notes 21. 24 pp.
Bennett, George W.
1943. Management of small artificial lakes:
a summary of fisheries investiga-
tions, 1938-1942. Ill. Nat. Hist.
Surv. Bul. 22(3) :357-76.
1947. Fish management—a substitute for
natural predation. N. Am. Wildlife
Conf. Trans. 12:276-84.
1948. The bass-bluegi!l combination in a
small artificial lake. Ill. Nat. Hist.
Surv. Bul. 24(3) :377-412.
1952. Pond management in Illinois. Jour.
Wildlife Mgt. 16(3) :249-53.
1954a. Largemouth bass in Ridge Lake,
Coles County, Illinois. Ill. Nat. Hist.
Surv. Bul. 26(2) :217-76.
1954b. The effects of a late-summer draw-
down on the fish pcpulation of Ridge
Lake, Coles County, Illinois. N. Am.
Wildlife Conf. Trans. 19:259-70.
Bennett, George W., David H. Thompson, and
Sam A. Parr
1940. Lake management reports. 4. A sec-
ond year of fisheries investigations
at Fork Lake, 1939. Ill. Nat. Hist.
Surv. Biol. Notes 14. 24 pp.
Birge, E. A.
1929. Fish and their food. Am. Fish. Soc.
Trans. for 1929, 59:188—-94.
Vol. 27, Art. 2
Boewe, G. H.
1939. Diseases of small grain crops in Illi- —
nois. Ill. Nat. Hist. Surv. Cire. 35.
130 pp.
Borodin, N.
1924. Age of shad (Alosa sapidissima Wil-
son) as determined by the scales.
Am. Fish. Soc. Trans. for
54:178-84.
Brendel, Frederick
1857. Historical researches upon the culti-
vated grain fruits in the state of IIli-
nois. Ill. Ag. Soc. Trans. for 1856- —
1857, 2:471-83.
1859a. Additions and annotations to Mr.
Lapham’s catalogue of Illinois plants.
Ill. Ag. Soc. Trans. for 1857-1858,
3:583-5.
1859b. The trees and shrubs in Illinois. Ill.
Ag. Soc. Trans. for 1857-1858, 3:588-
604.
1859c. The oaks of Illinois. Ill. Ag. Soc.
Trans. for 1857-1858, 3:605-31.
1859d. Forests and forest trees. Ill. Ag. Soc.
Trans. for 1857-1858, 3:651-61.
Botanical notes. Notices and addi-
tions to Illinois flora. Prairie Farmer,
n.s., 6(19):294-5. [Author’s name
given as Fred. Brendell.]
The water lily. On the peculiar
growth of the water lily (Nelumbium
luteum Willd.). Ml. Nat. Hist. Soc.
Trans. 2nd ed. Ser. 1, 1:65-7.
Occurrence of rare plants in Illinois.
Am. Nat. 4(6) :374.
[Brendel, Frederick]
1876. The tree in winter. IIl.
Hist. Bul. 1(1) :26-32.
Brendel, Frederick
1887. Flora Peoriana. The vegetation in
the climate of middle Illinois. J. W.
Franks and Sons, Peoria. 89 pp.
Brown, Louis G., and Lee E. Yeager
1860.
1861.
Mus. Nat.
1943. Survey of the Illinois fur resource.
Ill. Nat. Hist. Surv. Bul. 22(6) :435-
504.
1945. Fox squirrels and gray squirrels in
Illinois. Ill. Nat. Hist. Surv. Bul.
23(5) :449-536.
Bruce, Willis N.
1952. Automatic sprayer for control of bit-
ing flies on cattle. Ill. Nat. Hist.
Surv. Biol. Notes 27. 11 pp.
1953. A new technique in control of the
house fly. Ill. Nat. Hist. Surv. Biol.
Notes 33. 8 pp.
Bruce, W. N., and George C. Decker
1951. Tabanid control on dairy and beef
cattle with synergized pyrethrins.
Jour. Econ. Ent. 44(2) :154-9.
Experiments with several repellent
formulations applied to cattle for
control of stable flies. Jour. Econ.
Ent. 50(6) :709-13.
The relationship of stable fly abun-
dance to milk production in dairy
cattle. Jour. Econ. Ent. 51(3) :269-74.
OST.
1958.
1924, |
|
:
December, 1958
Brush, H. L.
1857. On the culture of the vine in IIli-
nois. Ill. Ag. Soc. Trans. for 1856—
1857, 2:407-12.
Burks, B. D.
1953. The mayflies, or Ephemeroptera, of
Illinois. Ill. Nat. Hist. Surv. Bul.
26(1) :1-216.
Burr, J. G.
1931. Electricity as a means of garfish and
carp control. Am. Fish. Soc. Trans.
for 1931, 61:174-81.
Burrill, Thomas J.
1874. Aggressive parasitism of fungi. III.
Hort. Soc. Trans. for 1873, ms.,
7:217-21.
1876. Lettuce mould and leaf blights. III.
Hort. Soc. Trans. for 1875, ms.,
9:139-44.
1877. Injurious fungi. Ill. Hort. Soc. Trans.
for 1876, n.s., 10:213-20.
1881. Blight, or bacteria-ferments, in fruit
trees. Ind. Hort. Soc. Trans. for
1880, 20:84-91.
1885. Parasitic fungi of Illinois—Part I.
Ill. Lab. Nat. Hist. Bul. 2(3) :141-
255.
1886. Annual address of the president:
Bacteria and disease. Am. Soc. Mi-
croscopists Proc. for 1886, 8:5-29.
Burrill, Thomas J., Corresponding Secretary
1887a. Thirteenth report . . . of the Board
of Trustees of the University of
Illinois (Illinois Industrial Univer-
sity) ... for the two years ending
September 30, 1886. 305 pp.
Burrill, Thomas J.
1887b. The forest-tree plantation. II]. Univ.
Rep. 13:255-82.
1887c. A disease of broom-corn and _ sor-
ghum. Soc. Prom. Ag. Sci. Proc.
8:30-6.
1888. Drouth and trees. Ill. Hort. Soc.
Trans. for 1887, n.s., 21:110-7.
1889a. Road and _ street horticulture. III.
Hort. Soc. Trans. for 1888, ns.,
22:153-9.
1889). The biology of ensilage. Ill. Ag.
Exp. Sta. Bul. 7:177-94.
1890. Canada thistles, their extermination.
Ill. Ag. Exp. Sta. Bul. 12:379-87.
1903. Experiments in spraying for bitter
rot. Ill. Hort. Soc. Trans. for 1902,
n.s., 36:54-66.
Campbell, F. L.
1946. Valediction: Theodore Henry Frison.
Sci. Monthly 62:91-3.
Carbine, W. F.
1939. Observations on the spawning habits
of centrarchid fishes in Deep Lake,
Oakland County, Michigan. N. Am.
Wildlife Conf. Trans. 4:275-87.
Carriel, Mary Turner
1911. The life of Jonathan Baldwin Tur-
ner. [Published by the author, Jack-
sonville, Illinois.] 298 pp.
LITERATURE CITED 221
Carter, J. Cedric
1939. Progress in the control of elm dis-
eases in nurseries. Ill. Nat. Hist.
Surv. Biol. Notes 10. 19 pp.
1941. Preliminary investigation of oak dis-
eases in Illinois. Ill. Nat. Hist. Sury.
Bul. 21(6) :195-230
1945. Wetwood of elms. III. Nat. Hist.
Surv. Bul. 23(4) :407-48.
1952. Distribution and spread of oak wilt
in Illinois. U. S. Dept. Ag. Plant
Dis. Reptr. 36(1) :26-7.
1955. Leo Roy Tehon, 1895-1954. Phyto-
pathology 45(3) :115.
Carter, J. C., and Noel B. Wysong
1951. Isolation of the oak wilt fungus from
swamp white oak. U. S. Dept. Ag.
Plant Dis. Reptr. 35(3) :173-4.
Carver, Jonathan
1778. Travels through the interior parts
of North-America, in the years 1766,
1767, and 1768. Printed for the au-
thor, London. 543 pp.
Chapman, Herman H., and Robert B. Miller
1924. Second report on a forest survey of
Illinois. The economics of forestry
in the state. Ill. Nat. Hist. Surv. Bul.
15(3) :46-172.
Coquillett, D. W.
1881. Larvae of Lepidoptera. Ill. Ent. Rep.
10:142-86.
[Coues, Elliott]
1 83. Birds and insects. Nuttall Ornith.
Club Bul. 8(2) :105-7.
Creager, Donald B.
194+1a. Ring spot of popular peperomias
caused by virus. Florists’ Rev.
87 (2256) :15-6.
1941. Control black mold of rose grafts by
chemical treatments. Florists’ Rev.
89 (2290) :21-2.
1941c. Control program for peony measles.
Florists’ Rev. 89(2296) :22-3.
1942. Thielavia root rot of sweet peas and
its control. II]. Florists’ Assn. Bul.
62 :284—5.
1943a. Spraying ground with Elgetol con-
trols peony disease. III. Florists’
Assn. Bul. 68:311-3.
1943b. Prevention of disease losses in
callas. Ill. Florists’ Assn. Bul.
73:340-3.
1943¢. Carnation mosaic. Phytopathology
33 (9) :823-7.
1944. How to recognize and control mosaic
on carnation plants. Florists’ Rev.
93 (2409) :27-9.
1945. Mosaic of the common coleus. Phyto-
pathology 35(4) :223-9.
Cresson, E. T., Aus. R. Grote, J. W.
McAllister, Benj. D. Walsh, Editors
1865. Answers to correspondents. Pract.
Ent. 1(3) :18-9.
Cunningham, Harrison E., Secretary
1928. Thirty-fourth report of the
Board of Trustees of the University
222
of Illinois for the two years ending
June 30, 1928. Ixi+840 pp.
Curl, E. A.
1953. Studies on the availability of oak
wilt inoculum in Illinois. Phytopa-
thology 43(9) : 469.
1955a. Natural availability of oak wilt in-
ocula. Ill. Nat. Hist. Surv. Bul.
26(3) :277-323.
1955b. Removal of spores from mycelial
mats and transmission of Endoconidi-
ophora fagacearum by air currents.
U. S. Dept. Ag. Plant Dis. Reptr.
39 (12) : 977-82.
Curl, E. A., G. J. Stessel, and Bert M.
Zuckerman
1952. Macroscopic growth of the oak wilt
fungus in nature. Phytopathology
42(1):6.
Subcortical mycelial mats and peri-
thecia of the oak wilt fungus in na-
ture. Phytopathology 43(2) :61-4.
Davis, John J.
1913. The Cyrus Thomas collection of
Aphididae, and a tabulation of spe-
cies mentioned and described in his
publications. Ill. Lab. Nat. Hist. Bul.
10(2) :97-121+2 pls.
Contributions to a knowledge of the
natural enemies of Phyllophaga. Ill.
Nat. Hist. Surv. Bul. 13(5) :53-138
+13 pls.
New species and varieties of Phyl-
lophaga. Ill. Nat. Hist. Surv. Bul.
13 (12) :329-38+6 pls.
Davis, N. S., Jr.. and Frank L. Rice
1883. Descriptive catalogue of North Amer-
ican Batrachia and Reptilia, found
east of Mississippi River. II]. Lab.
Nat. Hist. Bul. 1(5) :3-64.
DeLong, D. M.
1948. The leafhoppers, or Cicadellidae, of
Illinois (Eurymelinae-Balcluthinae).
Ill. Nat. Hist. Surv. Bul. 24(2) :97-
376.
Deyo, V. K., Chairman of Committee
1867. Report on president’s address. Ill.
Hort. Soc. Trans. for 1866, 11:57-8.
Durham, Leonard
1955. Effects of predation by cormorants
and gars on fish populations of ponds
in Illinois. Thesis submitted as par-
1953.
1919.
1920.
tial fulfillment for Ph.D. degree.
University of Illinois, Urbana. iv+
113 pp.
Eames, J. P.
1857. Evergreen trees on the prairie. III.
Ag. Soc. Trans. for 1856-1857, 2:
416-7.
Earle, Parker
1868. President Earle’s address. II]. Hort.
Soc. Trans. for 1867, n.s., 1:136-8.
Ecke, Dean H.
1955. The reproductive cycle of the Mearns
cottontail in Illinois. Am. Midland
Nat. 53(2) :294-311.
ILtinois NATURAL History SurRvEY BULLETIN
Vol. 27, Art. 2
Ecke, Dean H., and Ralph E. Yeatter
1956.
rabbits in Illinois. III.
Trans. for 1955, 48:208-14.
Eddy, Samuel
1927. The plankton of Lake Michigan. Ill. —
Nat. Hist. Surv. Bul. 17(4) : 203-32. ©
1931. The plankton of some sink hole ponds
in southern Illinois. Ill. Nat. Hist. —
Surv. Bul. 19(4) :449-67.
1932. The plankton of the Sangamon River
in the summer of 1929. Ill. Nat. Hist.
Surv. Bul. 19(5) :469-86.
Edwards, Samuel
1857. Cultivation of evergreens.
Soc. Trans. for 1856-1857, 2:413-5.
1868. Planting and cultivation of forest —
trees. Ill. Ag. Soc. Trans. for 1865— ;
1866, 6:283-6.
Elder, William H.
1946. Age and sex criteria and weights of
Canada geese.
10(2) :93-111.
Elder, William H., and Nina L. Elder
1949.
of goose flocks. Wilson Bul. 61(3):
133-40.
Engelmann, George
[1843.] Catalogue of a collection of plants —
made in Illinois and Missouri, by
Charles A. Geyer; with critical re-
marks, &c.
46(1) : 94-104.
English, L. L.
1958. Illinois trees and shrubs: their insect —
enemies. II], Nat. Hist. Surv. Cire.
47. 92 pp.
Eschmeyer, R. W.
1938. The significance of fish population
studies in lake management. N. Am.
Wildlife Conf. Trans. 3:458-68.
[Etter, S. M., Secretary]
1876.
ber 15, 1875). Springfield. 20 pp.
Etter, S. M., Secretary
1877.
tion of the State of Illinois (June 21,
22, 1877). Springfield. 27 pp.
Evers, Robert A.
1949. Setaria faberii in Illinois.
51 (612) :391-2.
1950. Andropogon elliottii Chapm. in Illi- —
nois. Rhodora 52(614) :45-6. 5
1951. Four plants new to the Illinois flora.
Rhodora 53(628) :111-3.
1955. Hill prairies of Illinois. Ill. Nat.
Hist. Surv. Bul. 26(5) :367—446.
1956. Two plants new to the Illinois flora.
Rhodora 58(686) :49-50.
Evers, Robert A., and John W. Thieret
1957. New plant records: Illinois and Indi-
ana. Rhodora 59(703) :181.
Ewing, Henry E.
1909. The Oribatoidea of Illinois. Ill. Lab.
Nat. Hist. Bul. 7(10) :337-89+3 pls.
Notes on the parasites of cottontail —
Acad. Sci. ©
Ill. Ag. |
Jour. Wildlife Mgt. —
Role of the family in the formation ©
Am. Jour. Sci. and Arts ©
Proceedings of, the Board of Educa- i
tion of the State of Illinois (Decem- —
Proceedings of the Board of Educa- j
Rhodora
p> eee aS
SS we Se he
er
December, 1958
Fawks, Elton
1957.
Our new hawk and owl law. III.
Audubon Soc. Bul. 1957(103) :1-2.
Finger, G. C., Frank H. Reed, and Leo R.
Tehon
1955.
Aromatic fluorine compounds as fun-
gicides. Ill]. Geol. Surv. Circ. 199. 15
Pp.
Flint, Wesley P., and John R. Malloch
1920.
The European corn-borer and some
similar native insects. II]. Nat. Hist.
Surv. Bul. 13(10) :287-305.
Forbes, Ernest Browning
1897.
1930.
A contribution to a knowledge of
North American fresh-water Cyclo-
pidae. Ill. Lab. Nat. Hist. Bul.
5 (2) :27-96.
Stephen Alfred Forbes: his ancestry,
education and character. Pp. 5-15 in
Memorial of the funeral services for
Stephen Alfred Forbes, Ph.D., LL.D.
University of Illinois Press, [Ur-
bana]. 40 pp.
Forbes, Stephen Alfred
1876.
1877.
[1878 ]a.
1878).
1880a.
1880.
1880c.
1880d.
1880¢.
[1880]f.
1881la.
1881.
1881c.
[1882]a.
List of Illinois Crustacea, with de-
scriptions of new species. Ill. Mus.
Nat. Hist. Bul. 1(1) :3-25.
Report on the Museum of Natural
History, at Normal. Ill. Supt. Pub.
Instr. Bien. Rep. for 1874-1876, 11:
324-31.
The food of Illinois fishes.
Nat. Hist. Bul. 1(2) :71-89.
Semi-annual report of the Director
of the State Laboratory of Natural
History, at Normal, Illinois. Filed
December 16, 1878. Springfield. 6
pp.
On some interactions of organisms.
Ill. Lab. Nat. Hist. Bul. 1(3) :3-17.
The food of fishes. Ill. Lab. Nat.
Hist. Bul. 1(3) :18-65.
On the food of young fishes.
Lab. Nat. Hist. Bul. 1(3) :66-79.
Il]. Lab.
Hl.
The food of birds. Ill. Lab. Nat.
Hist. Bul. 1(3) :80-148.
The food of birds. Ill. Hort. Soc.
Trans. for 1879, n.s., 13:120-72.
Report of the Director of the State
Laboratory of Natural History. 24
pp. [Also in Ill. Supt. Pub. Instr.
Bien. Rep. for 1878-1880, 13:127,
138-60.]
Supplementary report on the food of
the thrush family. III. Hort. Soc.
Trans. for 1880, n.s., 14:106-26.
A few notes on the food of the
meadow lark. Ill. Hort. Soc. Trans.
for 1880, n.s., 14:234~-7.
The English sparrow in Illinois. Am.
Nat. 15(5) : 392-3.
Report of the Director of the State
Laboratory of Natural History, for
the two years ending June 30, 1881,
and June 30, 1882. 12 pp. [Also in
Ill. Supt. Pub. Instr. Bien. Rep. for
1880-1882, 14:Lx—Lxx1.]
LITERATURE CITED
223
18824. The ornithological balance-wheel. III.
1883a
1883b
1883c.
1883d. Notes on economic ornithology.
1884.
1886a
Hort. Soc. Trans. for 1881, n.s., 15:
120-31.
. The regulative action of birds upon
insect oscillations. Ill. Lab. Nat. Hist.
Bul. 1(6) : 3-32.
. The food of the smaller fresh-water
fishes. Ill. Lab. Nat. Hist. Bul.
1(6) :65-94,
The first food of the common white-
fish. (Coregonus clupeiformis,
Mitch.) Ill. Lab. Nat. Hist. Bul.
1(6) :95-109.
Ill.
Hort. Soe. “Frans. for n.S.,
16:60-71.
A catalogue of the native fishes of
Illinois. Ill. Fish Commrs. Rep. for
1884:60-89.
. Miscellaneous essays on economic
entomology by the State Entomologist
and his entomological assistants.
Springfield, Illinois. 130 pp.
1882,
18864. Report of the Director of the State
1887.
1888.
1889.
[1890.]
1891.
1894.
1895a
1895.
1896.
Laboratory of Natural History. III.
Supt. Pub. Instr. Bien. Rep. for 1884—
1886, 16:LxX—LxII.
Report of the Director of the State
Laboratory of Natural History,
Champaign, Illinois. June 8, 1887.
4 pp.
Biennial report of the Director of
the State Laboratory of Natural His-
tory, Champaign, Illinois. October
31, 1888. 10 pp.
Fifteenth report of the State Ento-
mologist on the noxious and_ benefi-
cial insects of the state of Illinois
. . . for the years 1885 and 1886.
Springfield. vi+ 115 pp.
Biennial report of the Director of
the Illinois State Laboratory of Nat-
ural History, Champaign, Illinois,
1889-1890. 5 pp.
On the common white grubs.
nosterna and Cyclocephala).
Ent. Rep. 17:30-53.
Illinois State Laboratory of Natural
History, Champaign, Ill. Biennial
Report of the Director, 1893-1894.
Chicago. 36 pp.+17 pls.
. Illinois State Laboratory of Natural
History, Champaign, Illinois. Bien-
nial Report of the Director. 1893-
1894. Ill. Fish Commrs. Rep. for
1892-1894:39-52+4 pls.
Nineteenth report of the State Ento-
mologist on the noxious and benefi-
cial insects of the state of Illinois.
Eighth report of S. A. Forbes, for
the years 1893 and 1894. Springfield.
206 pp.
Illinois State Laboratory of Natural
History, Urbana, Ill. Biennial Re-
port of the State Laboratory and Spe-
cial Report of the University Biolog-
ical Experiment Station. 1895-1896,
Springfield. 31 pp.+20 pls,
(Lach-
Ill.
224
1900.
1901.
1907a.
1907).
1907c.
1908.
1909.
1912a.
1912).
1913.
1915.
1919a.
[1919] d.
1923.
1925.
1928.
I-ttinois NAtrurRAL History Survey BULLETIN
Recent work on the San Jose scale
in Illinois. Ill. Ent. Rep. 21:1-47.
Illinois State Laboratory of Natural
History. Biennial Report of the Di-
rector for 1899-[19]00. Urbana. 12
pp-
On the local distribution of certain
Illinois fishes: an essay in statistical
ecology. Ill. Lab. Nat. Hist. Bul.
7(8) : 273-303 +15 maps, 9 pls.
An ornithological cross-section of
Illinois in autumn. Ill. Lab. Nat.
Hist. Bul. 7(9) :305-35.
History of the former state natural
history societies of Illinois. Science,
n.s., 26(678) :892-8.
The mid-summer bird life of IIli-
nois: a statistical study. Am. Nat.
42 (500) :505-19.
The Illinois State Laboratory of Nat-
ural History and the Illinois State
Entomologist’s Office. Ill. Acad. Sci.
Trans. for 1909, 2:54-67.
What is the matter with the elms in
Illinois? Ill. Ag. Exp. Sta. Bul.
154:3-22.
The native animal resources of the
state. Ill. Acad. Sci. Trans. for 1912,
5:37-48.
The midsummer bird life of Illinois:
a statistical study. Ill. Lab. Nat.
Hist. Bul. 9(6) :373-85.
The insect, the farmer, the teacher,
the citizen, and the state. An ad-
dress delivered December 13, 1910,
to a joint meeting of teachers and
farmers at Normal, III. Illinois State
Laboratory of Natural History, Ur-
bana. 14 pp.
Forest and stream in Illinois. Illi-
nois Department of Registration and
Education, Springfield. 15 pp.
Recent forestry survey of Illinois.
Ill. Hort. Soc. Trans. for 1918, n.s.,
52:103-10.
The State Natural History Survey.
Ill. Blue Book for 1923-1924 :384~7.
The lake as a microcosm. IIl. Nat.
Hist. Surv. Bul. 15(9) :537—50.
The biological survey of a river sys-
tem—its objects, methods, and _ re-
sults. Ill. Nat. Hist. Surv. Bul.
17 (7) :277-84.
Forbes, Stephen A., and Alfred O. Gross
1921.
The orchard birds of an IIlinois sum-
mer. Ill. Nat. Hist. Surv. Bul. 14(1):
1-8+6 pls.
The numbers and local distribution
in summer of Illinois land birds of
the open country. Ill. Nat. Hist.
Surv. Bul. 14(6) :187-218+36 pls.
On the numbers and local distribu-
tion of Illinois land birds of the open
country in winter, spring, and fall.
Ill. Nat. Hist. Surv. Bul. 14(10) : 397-
453.
Forbes, Stephen A., and Robert B. Miller
1920.
Concerning a forestry survey and a
Forbes,
Richa
[1908.]
1913.
1919.
Forsberg, Junius L.
1947.
1955a.
1955.
1957.
Forsberg, J. L., and G. H. Boewe
1945.
Francis,
1859a.
1859.
Frison,
1929.
1931.
1933,
1935,
1937.
1938.
1940.
1942a.
Vol. 27, Art. 2
forester for Illinois. Ill. Nat. Hist.
Surv. Cire. 8. (Forestry Cire. 1.)
7 pp.
Stephen Alfred, and Robert Earl
rdson
The fishes of Illinois. Illinois State
Laboratory of Natural History, [Ur- —
bana]. cxxxit+357 pp.+separate at- —
las containing 102 maps. Bs
Studies on the biology of the upper
Illinois River. Ill. Lab. Nat. Hist.
Bul. 9(10) :481-574+21 pls.
Some recent changes in Illinois River
biology. Ill. Nat. Hist. Surv. Bul.
13(6) :139-56.
When we're sick. [Two virus dis-
eases of carnations.] Here We Grow
2(3) :[22-3].
Fusarium disease of gladiolus: its —
causal agent. Ill. Nat. Hist. Surv.
Bul. 26(6) :447-503.
The use of insecticides as corm and
soil treatments for control of bac-
terial scab of gladiolus. U. S. Dept.
Ag. Plant Dis. Reptr. 39(2) :106-14.
A vascular form of the Curvularia
disease of gladiolus. Phytopathology
47(1) :12.
Violet scab found in Illinois for the
first time. U. S. Dept. Ag. Plant
Dis. Reptr. 29(25/26) :680.
S., Editor
Illinois Natural History Society
[1858]. Ill. Ag. Soc. Trans. for 1857—
1858, 3:637-61.
Illinois Natural History
[1859]. . Il. Ag». Sor
1857-1858, 3:662-85.
Theodore H.
Fall and winter stoneflies, or Plecop-
tera, of Illinois. Ill. Nat. Hist. Surv.
Bul. 18(2) :345-409.
State Natural History Survey. IIl.
Blue Book for 1931-1932:387-400.
Economic problems of Illinois’ fields,
forests, and streams solved by Nat-
ural History Survey. Ill. Blue Book
for 1933-1934:477-92.
The stoneflies, or Plecoptera, of IlIli-
Trans. for
nois. Ill. Nat. Hist. Surv. Bul. 20(4): —
281-471.
Studies of Nearctic aquatic insects.
II. Descriptions of Plecoptera. Ill.
Nat. Hist. Surv. Bul. 21(3) :78-99.
Advances in the renewable natural
resources program of Illinois. Ill.
Acad. Sci. Trans. for 1938, 31(1):
19-34.
New wildlife
under way
5(1) 28-9, 16.
Studies of North American Plecop-
tera, with special reference to the
fauna of Illinois. Ill. Nat. Hist.
Surv. Bul. 22(2) :235-355.
restoration
in Illinois.
program
Ill. Cons.
Society —
December, 1958
1942b. The conservation research program
of the Illinois Natural History Sur-
vey. Ill. Acad. Sci. Trans. for 1942,
35 (1) :5-12.
Galusha, O. B.
1881. [Comment following presentation of
“A few notes on the food of the
meadow lark,’ by S. A. Forbes.] III.
Hort. Soc. Trans. for 1880, 14:238.
Garman, H.
1890. A preliminary report on the ani-
mals of the Mississippi bottoms near
Quincy, Illinois, in August, 1888.
Part I. Ill. Lab. Nat. Hist. Bul.
3(9) :123-84.
Garman, Philip
1917. The Zygoptera, or
Illinois. Ill. Lab. Nat.
12 (4) :411-587+ 16 pls.
Gates, Frank Caleb
damsel-flies, of
Hist. Bul.
1912. The vegetation of the beach area in
northeastern Illinois and _ southeast-
ern Wisconsin. III. Lab. Nat. Hist.
Bul. 9(5) :255-372 + 20 pls.
Glasgow, Robert D.
1916. Phyllophaga Harris (Lachnosterna
Hope): a revision of the synonymy,
and one new name. III. Lab. Nat.
Hist. Bul. 11(5) :365-79.
Gleason, Henry Allan
1910. The vegetation of the inland sand
deposits of Illinois. Ill. Lab. Nat.
Hist. Bul. 9(3) :23-174+ 20 pls.
Goding, F. W.
1885. Biographical sketch of William Le
Baron, late State Entomologist of
Illinois. Ent. Am. 1(7) :122-5.
1889. A pen sketch of Cyrus Thomas, third
State Entomologist. II]. Hort. Soe.
Trans. for 1888, n.s., 22:106-8.
Gow, A. M.
1861. Natural history in schools. Ill. Nat.
Hist. Soc. Trans. 2nd ed. Ser. 1, 1:
87-97.
Greeley, Horace
1870. Insect depredations.
Bot. 2(10) :301.
Gross, Alfred O.
1921. The dickcissel (Spiza americana) of
the Illinois prairies. Auk 38(1) :1-26;
38 (2) :163-84.
Hall, R. Clifford, and O. D. Ingall
1911. Forest conditions in Illinois. II]. Lab.
Nat. Hist. Bul. 9(4) :175-253 + 16 pls.
Hansen, Donald F.
1951. Biology of the white crappie in IIli-
nois. Ill. Nat. Hist. Surv. Bul.
25(4) :211-65.
Hanson, Harold C.
1949a. Trapping and
geese. Ill. Nat.
Notes 20. 8 pp.
1949b. Methods of determining age in Can-
ada geese and other waterfowl. Jour.
Wildlife Mgt. 13(2) :177-83.
Am. Ent. and
handling Canada
Hist. Surv. Biol.
LITERATURE CITED 225
1953a. Aids for the exploration of the avian
cloaca for characters of sex and age.
Jour. Wildlife Mgt. 17(1) :89-90.
1953b. Inter-family dominance in Canada
geese. Auk 70(1):11-6.
1954. Apparatus for the study of incu-
bated bird eggs. Jour. Wildlife Mgt.
18 (2) :191-8.
A three-year survey of Ornithofilaria
sp. microfilariae in Canada geese.
Jour. Parasitol. 42(5) :543.
Hanson, Harold C., and Campbell Currie
1957. The kill of wild geese by the na-
tives of the Hudson—James Bay re-
gion. Arctic 10(4) :211-29.
Hanson, Harold C., and Richard E. Griffith
1956.
1952. Notes on the south Atlantic Canada
goose population. Bird-Banding
23(1) :1-22.
Hanson, Harold C., and Charles W. Kossack
1950. “Flying acrobat” gains in Illinois:
Doves on upswing but need manag-
ing. Outdoors in Ill. 16(3) :30-1.
1957a. Methods and criteria for aging incu-
bated eggs and nestlings of the
mourning dove. Wilson Bul. 69(1):
91-101.
1957b. Weight and body-fat relationships of
mourning doves in Illinois. Jour.
Wildlife Mgt. 21(2) :169-81.
Hanson, Harold C., Norman D. Levine, and
Virginia Ivens
1957. Coccidia (Protozoa: Eimeriidae) of
North American wild geese and
swans. Can. Jour. Zool. 35(6) :715-
33.
Hanson, Harold C., Norman D. Levine, and
Sidney Kantor
1956. Filariae in a wintering flock of Can-
ada geese. Jour. Wildlife Mgt. 20
(1) :89-92.
Hanson, Harold C., Norman D. Levine,
Charles W. Kossack, Sidney Kantor, and
Lewis J. Stannard
1957. Parasites of the mourning dove
(Zenaidura macroura carolinensis) in
Illinois. Jour. Parasitol. 43 (2) : 186-93.
Hanson, Harold C., and Robert H. Smith
1950. Canada geese of the Mississippi fly-
way, with special reference to an
Illinois flock. Ill. Nat. Hist. Surv.
Bul. 25(3) :67-210.
Harris, Hubert A.
1932. Initial studies of American elm dis-
eases in Illinois. Ill. Nat. Hist. Surv.
Bul. 20(1) :1-70.
Hart, Charles Arthur
1919. The Pentatomoidea of Illinois, with
keys to the Nearctic genera. Ill.
Nat. Hist. Surv. Bul. 13(7) :157-223
+6 pls.
Hart, Charles A., and Henry Allan Gleason
1907. On the biology of the sand areas of
Illinois. Ill. Lab. Nat. Hist. Bul.
7(7):137-272+1 map, 16 pls,
226
Hebard, Morgan
1934. The Dermaptera and Orthoptera of
Illinois. Ill. Nat. Hist. Surv. Bul.
20(3) :125-279.
Hempel, Adolph
1896. Descriptions of new species of Rotif-
era and Protozoa from the Illinois
River and adjacent waters. III. Lab.
Nat. Hist. Bul. 4(10) :310-7+5 pls.
1899. A list of the Protozoa and Rotifera
found in the Illinois River and adja-
cent lakes at Havana, Ill. Ill. Lab.
Nat. Hist. Bul. 5(6) :301-88.
Hesselschwerdt, Robert E.
1942. Use of den boxes in wildlife restora-
tion on intensively farmed areas.
Jour. Wildlife Mgt. 6(1) :31-7.
Himelick, E. B., and E. A. Curl
1955. Experimental transmission of the
oak wilt fungus by caged squirrels.
Phytopathology 45(11) :581-4.
1958. Transmission of Ceratocystis faga-
cearum by insects and mites. U. S.
Dept. Ag. Plant Dis. Reptr. 42(4):
538-45.
Himelick, E. B., E. A. Curl, and Bert M.
Zuckerman
1954. Tests on insect transmission of oak
wilt in Illinois. U. S. Dept. Ag.
Plant Dis. Reptr. 38(8) :588-90.
Himelick, Eugene B., Richard D. Schein, and
E. A. Curl
1953. Rodent feeding on mycelial pads of
the oak wilt fungus. U. S. Dept. Ag.
Plant Dis. Reptr. 37(2) :101-3.
Hoff, C. Clayton
1949. .The pseudoscorpions of Illinois. III.
Nat. Hist. Surv. Bul. 24(4) :413-98.
Hoffman, Paul F.
1953. Oak wilt fungus pathogenic on
Quercus chrysolepis and Quercus
agrifolia. U. S. Dept. Ag. Plant
Dis. Reptr. 37(10) :527.
Hoffman, Paul F., and Bert M. Zuckerman
1954. Oak wilt fungus labeled with C*.
Science, n.s., 120(3107) :106-8.
Hoffmeister, Donald F., and Carl O. Mohr
1957. Fieldbook of Illinois mammals. III.
Nat. Hist. Surv. Man. 4. 233 pp.
Holder, R. H.
1861a. Taxidermy. Directions for collecting
and preserving specimens in orni-
thology. Ill. Ag. Soc. Trans. for
1859-1860, 4:597-603.
18614. Birds of Illinois. Catalogue. Ill.
Ag. Soc. Trans. for 1859-1860, 4:
605-13.
Hood, J. Douglas
1908. New genera and species of Illinois
Thysanoptera. II]. Lab. Nat. Hist.
Bul. 8(2) :361-79.
Hottes, Frederick C., and Theodore H. Frison
1931. The plant lice, or Aphiidae, of IIli-
nois. Ill. Nat. Hist. Surv. Bul. 19(3):
123-447.
I-Ltrnois NaturAL History SurvEY BULLETIN
Vol. 27, Art. 2
Hovey, Charles E.
1859. State Normal University. Ill. Ag.
Soc. Trans. for 1857-1858, 3:398—-402.
Howard, L. O.
1932. Biographical memoir of Stephen Al-
fred Forbes 1844-1930. Natl. Acad.
Sci. Biog. Mem. 15(1) :1-54.
The insect menace. D. Appleton-
Century Company, New York. 347
pp-
Hubbs, Carl L.
1930. Fishery research in Michigan. Am.
Fish. Soc. Trans. for 1930, 60:182-6.
Illinois General Assembly
1861. Private laws of the State of Illinois,
passed by the Twenty-Second Gen-
eral Assembly, . . . Springfield. 760
1933.
pp.
Public laws of the State of Illinois,
passed by the Twenty-Fifth General
Assembly . . . Springfield. 205 pp.
Public laws of the State of Illinois,
passed by the Twenty-Sixth General
Assembly, . . . Springfield. 434 pp.
Public laws of the State of Illinois,
passed by the Twenty-Seventh Gen-
eral Assembly, . . . Springfield. 800
+ vii pp.
Laws of the State of Illinois: passed
by the Thirtieth General Assembly.
. . . Springfield. 229-+iv pp.
Laws of the State of Illinois: enacted
by the Thirty-First General Assem-
bly. . . . Springfield. 326+ xii pp.
Laws of the State of Illinois, enacted
by the Thirty-Fourth General As-
sembly, .. . Springfield. 268+ vi pp.
Laws of the State of Illinois, enacted
by the Thirty-Fifth General Assem-
bly, .. . Springfield. 338 pp.
Laws of the State of Illinois enacted
by the Fiftieth General Assembly at
the regular biennial session. . .
Springfield. xxiiit+ 844 pp.
Laws of the State of Illinois enacted
by the Seventieth General Assembly
at the regular biennial session . . .
Springfield. 2 vols. 2,976 pp.
Illinois House of Representatives
1957. Journal of the Illinois House of Rep-
resentatives of the Seventieth Gen-
eral Assembly of the State of Illinois,
No. 38, for Tuesday, April 9, 1957.
42 pp.
Johnson, Benjamin F.
1861. Report on farms and nurseries. III.
Ag. Soc. Trans. for 1859-1860, 4:83-
95.
Jordan, David S.
1878. A catalogue of the fishes of IIlinois.
Ill. Lab. Nat. Hist. Bul. 1(2) :37—70.
Jordan, James S., and Frank C. Bellrose
1867.
1869.
1872.
1957.
1950. Shot alloys and lead poisoning in
waterfowl. N. Am. Wildlife Conf.
Trans. 15:155-68.
1951. Lead poisoning in wild waterfowl.
ere
Ca ek ee 6 ee
Serie Po"
December, 1958
Ill. Nat. Hist. Surv. Biol. Notes 26.
27 pp.
Kennicott, John A., Corresponding Secretary
1855. Transactions of the Illinois State
Agricultural Society: . . . 1853-1854.
Springfield. viii 612+ iv pp.
Kennicott, John A., Editor
1857. Transactions of the Illinois State
Agricultural Society, . . . 1856-1857.
Springfield. xvi+ 684 pp.+14 pls.
Kennicott, Robert
1855. Catalogue of animals observed in
Cook County, Illinois. Ill. Ag. Soc.
Trans. for 1853-1854, 1:577-95.
Knight, Harry H.
1941. The plant bugs, or Miridae, of Illi-
nois. Ill. Nat. Hist. Surv. Bul. 22(1) :
1-234.
Kofoid, C. A.
1897. Plankton studies. I. Methods and ap-
paratus in use in plankton investiga-
tions at the biological experiment
station of the University of Illinois.
Ill. Lab. Nat. Hist. Bul. 5(1) :1-26
+7 pls.
Plankton studies. II. On Pleodorina
illinoisensis, a new species from the
plankton of the Illinois River. III.
Lab. Nat. Hist. Bul. 5(5) :273-300.
Plankton studies. III. On Platydorina,
a new genus of the family Volvoci-
dae, from the plankton of the Illinois
River. Ill. Lab. Nat. Hist. Bul.
5(9) :419-40+1 pl.
Plankton studies. IV. The plankton
of the Illinois River, 1894-1899, with
introductory notes upon the hydrog-
raphy of the Illinois River and its
basin. Part I. Quantitative investi-
gations and general results. Ill. Lab.
Nat. Hist. Bul. 6(2) :95-635+-50 pls.
Plankton studies. V. The plankton
of the Illinois River, 1894-1899.
Part IJ. Constituent organisms and
their seasonal distribution. II]. Lab.
Nat. Hist. Bul. 8(1) :3-360.
Kossack, Charles W.
1898.
1899,
1903.
1908.
1952. Banding nestling mourning doves.
Bird-Banding 23(1) :28-9.
1955. Mourning dove banding project. In-
land Bird Banding News 27(1) :1-8.
Kossack, Charles W., and Harold C. Hanson
1953. Unisexual broods of the mourning
dove. Jour. Wildlife Mgt. 17(4):
541.
1954. Fowlpox in the mourning dove. Am.
Vet. Med. Assn. Jour. 124(924):
199-201.
Langlois, T. H.
1937. Recommendations for improving bass
fishing in Ohio. N. Am. Wildlife
Conf. Trans. 2:649-52.
Lapham, I. A.
1857a. Catalogue of the plants of the state
of Illinois. Ill. Ag. Soc. Trans. for
1856-1857, 2:492-550.
LITERATURE CITED 227,
1857b. The native, naturalized and culti-
vated grasses of the state of Illinois.
Ill. Ag. Soc. Trans. for 1856-1857,
2:551-613.
Large, Thomas
[1903.] A list of the native fishes of Illinois,
with keys. Append. to Ill. Fish
Commrs. Rep. 1900-1902. 30 pp.
Larimore, R. Weldon
1949. Changes in the cranial nerves of the
paddlefish, Polyodon spathula, ac-
companying development of the ros-
trum. Copeia 1949(3) :204-12.
Gametogenesis of Polyodon spathula
(Walbaum): a basis for regulation
of the fishery. Copeia 1950(2) :116-
24.
Home pools and homing behavior of
smallmouth black bass in Jordan
Creek. II]. Nat. Hist. Surv. Biol.
Notes 28. 12 pp.
Minnow productivity in a small IIli-
nois stream. Am. Fish. Soc. Trans.
for 1954, 84:110-6.
Ecological life history of the war-
mouth (Centrarchidae). Ill. Nat.
Hist. Surv. Bul. 27(1) :1-83.
Larimore, R. Weldon, Quentin H. Pickering,
and Leonard Durham
1952. An inventory of the fishes of Jordan
Creek, Vermilion County, Illinois.
Ill. Nat. Hist. Surv. Biol. Notes 29.
26 pp.
Le Baron, William
1855. Observations upon some of the birds
of Illinois most interesting to the ag-
riculturist. Ill. Ag. Soc. Trans. for
1853-1854, 1:559-65.
First annual report on the noxious
insects of the state of Illinois.
Springfield. Pp. 1-96. [II]. Ent. Rep.
2.]
Second annual report on the noxious
insects of the state of Illinois.
Springfield. Pp. 97-166+ index. [IIl.
Ent. Rep. 3.]
Third annual report on the noxious
insects of the state of Illinois.
Springfield. Part 1, pp. 167-202.
Part 2. 37 pp. [Ill. Ent. Rep. 4.]
Outlines of entomology, published in
connection with the author’s annual
reports upon injurious insects. Part
1. Including the order of Coleoptera.
Ill. Ent. Rep. 5. xvui+199 pp.
Leigh, W. Henry
1940. Preliminary studies on parasites of
upland game birds and fur-bearing
mammals in Illinois. Ill. Nat. Hist.
Surv. Bul. 21(5) :185-94.
Leopold, Aldo
1950.
1952.
1955.
Sie
1871.
1872.
1873.
1874.
1931. Report on a game survey of the north
central states. Sporting Arms and
Ammunition Manufacturers’ Insti-
tute, Madison, Wis. 299 pp.
1933. Game management. Charles Scrib-
ner’s Sons, New York. xxit481 pp.
228 I-ttinois NaturAL History SurvEY BULLETIN
Levine, Norman D.
1952. Eimeria magnalabia and Tyzzeria
sp. (Protozoa:Eimeriidae) from the
Canada goose. Cornell Vet. 42(2):
247-52.
A review of the coccidia from the
avian orders Galliformes, Anseri-
formes and Charadriiformes, with
descriptions of three new species.
Am. Midland Nat. 49(3) :696-719.
Leucocytozoon in the avian order
Columbiformes, with a description of
L. marchouxi Mathis and Leger 1910
from the mourning dove. Jour. Pro-
tozool. 1(2) : 140-3.
Levine, Norman D., and Harold C. Hanson
1953. Blood parasites of the Canada goose,
Branta canadensis interior. Jour.
Wildlife Mgt. 17(2):185-96+1 pl.
Lill, Althea "
1942. Natural History Survey Library, an-
nual report, May 1, 1941-May 31,
1942. 6 pp. [Not published, but
available in University of Illinois
Library, Urbana.]
Lincoln, Frederick C.
1924. Returns from banded birds, 1920 to
1923. U. S. Dept. Ag. Dept. Bul.
1268. 56 pp.
Lord, Rexford D., Jr.
1958. The importance of juvenile breeding
to the annual cottontail crop. N. Am.
Wildlife Conf. Trans. 23:269-75.
Loucks, W. E.
1894. The life history and distribution of
the prothonotary warbler in Illinois.
Ill. Lab. Nat. Hist. Bul. 4(3) :10-35.
Low, Jessop B., and Frank C. Bellrose
1944. The seed and vegetative yield of
waterfowl food plants in the Illinois
River valley. Jour. Wildlife Met.
8(1):7-22+1 pl.
Lucas, Clarence R.
1939. Game fish management. Am. Fish.
Soc. Trans. for 1938, 68:67-74.
Malloch, J. R.
1915. The Chironomidae, or midges, of
Illinois, with particular reference to
the species occurring in the Illinois
River. Ill. Lab. Nat. Hist. Bul.
10(6) :275-543+24 pls.
A preliminary classification of Dip-
tera, exclusive of pupipara, based
upon larval and pupal characters,
with keys to imagines in certain fam-
ilies. Part I. Ill. Lab. Nat. Hist.
Bul. 12(3) :161-409+30 pls.
The North American species of the
genus Tiphia (Hymenoptera, Acu-
leata) in the collection of the Illinois
State Natural History Survey. Ill.
Nat. Hist. Surv. Bul. 13(1):1-24+1
pl.
A new species of Erythroneura (Ty-
phlocybidae, Hem.-Hom.). Brooklyn
Ent. Soc. Bul., n.s., 16(1) : 25.
1955.
1954.
1917.
1918.
Vol. 27, Art. 2
Mann, Roberts, Editor
1956. Policies of the Department of Con-
servation: a report by the Conserva-
tion Advisory Board. State of Illi-
nois, Springfield. 36 pp.
Markus, Henry C.
1932. The extent to which temperature
changes influence food consumption
in largemouth bass (Huro floridana).
Am. Fish. Soc. Trans. for 1932,
62 :202-10.
Marquardt, William C., and Thomas G. Scott
1952. It’s in the bag. Ill. Wildlife 7(2):
4-5.
Marshall, Helen E.
1956. Grandest of enterprises: Illinois State
Normal University, 1857-1957. Illi-
nois State Normal University, Nor-
mal. xiiit+355 pp.
McAtee, W. L.
1917. Life and writings of Professor F. E.
L. Beal. Auk 34(3) :243-64.
Notes on a collection of Erythroneura
and Hymetta (Eupterygidae) chief-
ly from Illinois, with descriptions of
new forms. III]. Nat. Hist. Surv. Bul.
15(2) :39-44.
Notes on Homoptera from Illinois,
with descriptions of new forms,
chiefly Eupteryginae. II]. Nat. Hist.
Surv. Bul. 16(3) :127-36.
McDougall, Walter B.
1924.
1926.
1917. Some edible and poisonous mush-
rooms. Ill. Lab. Nat. Hist. Bul.
11(7) :413-555.
Mead, S. B.
1846. Catalogue of plants growing spon-
taneously in the state of Illinois, the
principal part near Augusta, Han-
cock County. Prairie Farmer 6(1):
35-6; 6(2):60; 6(3):93; 6(4) :119-
22.
Middleton, Nettie F
1878. A new species of Aphis, of the genus
Colopha. Ill. Lab. Nat. Hist. Bul.
IM(2)e2073
Miller, Robert B.
1923. First report on a forest survey of
Illinois. Ill. Nat. Hist. Surv. Bul.
14(8) :291-377+27 pls.
Miller, Robert Barclay, and L. R. Tehon
1929. The native and naturalized trees of
Illinois. Ill. Nat. Hist. Surv. Bul.
18 (1) :1-339.
Minier, George W.
1865. Cultivation of forest trees. Ill. Ag.
Soc. Trans. for 1861-1864, 5:779-80.
1868. On the cultivation of forest trees.
Ill. Ag. Soc. Trans. for 1865-1866,
6:279-82.
Mohr, Carl O.
1943a. Illinois
income. Ill.
22(7) :505-37.
1943b. A comparison of North American
distribution and
Hist. Surv. Bul.
furbearer
Nat.
December, 1958
small-mammal censuses. Am. Mid-
land Nat. 29(3) :545-87.
1947a. Table of equivalent populations of
North American small mammals.
Am. Midland Nat. 37(1) : 223-49.
1947b. Major fluctuations of some Illinois
mammal populations. Ill. Acad. Sci.
Trans. for 1947, 40:197-204.
Moore, J. Percy
1901. The Hirudinea of Illinois. Il]. Lab.
Nat. Hist. Bul. 5(12):479-92+6 pls.
Mulvihill, Wm. F., and L. D. Cornish
1930. Flood control report: an enginecring
study of the flood situation in the
state of Illinois. Illinois Division of
Waterways, Springfield. 402 pp.
Mygatt, E. G.
1855. Bark louse of the apple tree. III.
Ag. Soc. Trans. for 1853-1854, 1:
514-7.
Needham, James G., and Charles A. Hart
1903. The dragon-flies (Odonata) of IIli-
nois, with descriptions of the im-
mature stages. Part I. Petaluridae,
Aeschnidae, and Gomphidae. Ill.
Lab. Nat. Hist. Bul. 6(1) :1-94-+1 pl.
Nelson, E. W.
1876. A partial catalogue of the fishes of
Illinois. Ill. Mus. Nat. Hist. Bul.
1(1) 233-52.
Nevin, James
1898. Artificial propagation versus a close
season for the Great Lakes. Am.
Fish. Soc. Proc. 27:17-25.
O’Donnell, D. John
1935. Annotated list of the fishes of IIli-
nois. Ill. Nat. Hist. Surv. Bul. 20(5) :
473-500.
Ordway, O.
1857. Treatise on the advantages to be de-
rived from the cultivation of flowers.
Ill. Ag. Soc. Trans. for 1856-1857,
2:401-6.
Pietsch, Lysle R.
195+. White-tailed deer populations in IIli-
nois. Ill. Nat. Hist. Surv. Biol. Notes
34. 22 pp.
1957. The beaver in Illinois. Ill. Acad.
Sci. Trans. for 1956, 49:193-201.
Pillsbury, William L., Corresponding Secre-
tary
1892. Sixteenth report .. . of the Board
of Trustees of the University of Illi-
nois . . . for the two years ending
September 30, 1892. 296 pp.
Seventeenth report ... of the Board
of Trustees of the University of IIli-
nois . .. for the two years ending
September 30, 1894. 338 pp.
Eighteenth report ... of the Board
of Trustees of the University of IIli-
nois . . . for the two years ending
September 30, 1896. 334 pp.+20 pls.
Nineteenth report . . . of the Board
of Trustees of the University of Illi-
1894.
1896.
1898.
LITERATURE CITED 229
am
nois . . . for the two years ending
September 30, 1898. 363 pp.
Twentieth report... of the Board
of Trustees of the University of IIli-
nois ... for the two years ending
September 30, 1900. xix+384 pp.
Twenty-first report... of the Board
of Trustees of the University of IIli-
nois . . . for the two years ending
September 30, 1902. xxiit+383 pp.
Twenty-third report ... of the Board
of Trustees of the University of IIli-
nois . . . for the two years ending
September 30, 1906. xxv +498 pp.
Powers, Edwin B.
1918. A collecting bottle especially adapted
for the quantitative and qualitative
determination of dissolved gases,
particularly very small quantities of
oxygen. Ill. Lab. Nat. Hist. Bul.
11(10) :577-8.
Pratten, Henry
1855. Catalogue of the birds of Illinois.
Ill. Ag. Soc. Trans. for 1853-1854,
1:598-609.
Reynolds, John P., Corresponding Secretary
1901.
1902.
1906.
1861. ‘Transactions of the Illinois State Ag-
ricultural Society ... Vol. IV, 1859-
1860. Springfield. 698+ iy pp.
1865. Transactions of the Illinois State Ag-
ricultural Society . .. Vol. V, 1861-
1864. Springfield. 992+ vii pp.
[Reynolds, John P.]
1866. Address of the president. Ill. Hort.
Soc. Trans. for 1865, 10:7-10.
Reynolds, John P., Corresponding Secretary
1868. Transactions of the Illinois State
Agricultural Society . Vol. VI,
1865-1866. Springfield. xxxv+ 666 +
XXIV pp.
Richardson, Robert E.
1921. The small bottom and shore fauna
of the middle and lower Illinois
River and its connecting lakes, Chilli-
cothe to Grafton: its valuation; its
sources of food supply; and its rela-
tion to the fishery. II]. Nat. Hist.
Surv. Bul. 13(15) :363—522.
1925a. Changes in the small bottom fauna
of Peoria Lake, 1920 to 1922. Ili.
Nat. Hist. Surv. Bul. 15(5) :327-88.
1925h. Illinois River bottom fauna in 1923.
Ill. Nat. Hist. Surv. Bul. 15(6) :391-
422.
The bottom fauna of the middle IIli-
nois River, 1913-1925: Its distribu-
tion, abundance, valuation, and index
value in the study of stream pollu-
tion. Ill. Nat. Hist. Surv. Bul. 17(12):
387-475.
Ridgway, Robert
1881. A revised catalogue of the birds
ascertained to occur in Illinois. II.
Lab. Nat. Hist. Bul. 1(4) : 163-208.
The ornithology of Illinois. Part 1.
1928.
1889.
230
Descriptive catalogue. Vol. I. Spring-
field. viii+ 520 pp.
1895. The ornithology of Illinois. Part 1.
Descriptive catalogue. Vol. II.
Springheld. 282 pp.
1901. The birds of north and middle Amer-
ica: A descriptive catalogue of the
higher groups, genera, species, and
subspecies of birds known to occur in
North America, from the Arctic lands
to the Isthmus of Panama, the West
Indies and other islands of the Car-
ibbean Sea, and the Galapagos Ar-
chipelago. U.S. Natl. Mus. Bul. 50.
Part 9b. 3x75" pp:
Riley, Charles V.
1866. Entomological notes. Prairie Farmer,
n.s., 17(25) :432.
Riley, Charles V., Editor
1869 In memoriam. [Brief biography of
-70. Benjamin D. Walsh.] Am. Ent. 2(3):
65-8.
Robertson, William B., Jr.
1958. Investigations of ring-necked pheas-
ants in Illinois. Ill. Dept. Cons.
Tech. Bul. 1. 138 pp.
Roe, R., and Henry Schmidt
1897. Report of the Commissioners. III.
Fish Commrs. Rep. 1894-1896. 21 pp.
Ross, Herbert H.
1937. Studies of Nearctic aquatic insects.
I. Nearctic alder flies of the genus
Sialis (Megaloptera, Sialidae). Ill.
Nat. Hist. Surv. Bul. 21(3): 57-78,
98-9.
1944. The caddis flies, or Trichoptera, of
Illinois. Ill. Nat. Hist. Surv. Bul.
23 (1) :1-326.
1947. The mosquitoes of Illinois (Diptera,
Culicidae). Ill. Nat. Hist. Surv. Bul.
24(1) :1-96.
1956. Evolution and classification of the
mountain caddisflies.
Illinois Press, Urbana.
Sargent, C. S.
1889. Portions of the journal of André
Michaux, botanist, written during his
travels in the United States and Can-
ada, 1785 to 1796. With an intro-
duction and explanatory notes. Am.
Phil. Soc. Proc. 26(129) :1-145.
Schacht, Frederick William
University of
213 pp.
1897. The North American species of
Diaptomus. Il. Lab. Nat. Hist. Bul.
5(3) :97-223.
1898. The North American Centropagidae
belonging to the genera Osphranti-
cum, Limnocalanus, and Epischura.
Ill. Lab. Nat. Hist. Bul. 5(4) :225-70.
Schenck, Norman C., and J. C. Carter
1954. A fungistatic substance extracted
from vitrain. Science, n.s., 119(3085) :
213-4.
Scott, Thomas G.
1943. Some food coactions of the northern
plains red fox. Ecol. Monog. 13(4):
427-79.
ILttinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 2
1947. Comparative analysis of red fox
feeding trends on two central Iowa
areas. lowa Ag. Exp. Sta. Res. Bul.
353 :427-87.
1955. An evaluation of the red fox. IIl.
Nat. Hist. Surv. Biol. Notes 35. 16
pp.
1957. Legal protection for hawks and owls
in Illinois. Ill. Wildlife 12(2) :[3-5].
Scott, Thomas G., and Willard D. Klimstra
1954. Report on a visit to quail manage-
ment areas in southeastern United
States. Ill. Wildlife 9(3) :5-9.
1955. Red foxes and a declining prey pop-
ulation. South. Ill. Univ.
Ser. 1. 123 pp.
Sharpe, Richard W.
1897. Contribution to a knowledge of the
North American fresh-water Ostra-
coda included in the families Cythe-
ridae and Cyprididae. Ill. Lab. Nat.
Hist. Bul. 4(15):414-84+10 pls.
Shelford, Victor E.
1917. An experimental study of the effects
of gas waste upon fishes, with espe-
cial reference to stream pollution. II].
Lab. Nat. Hist. Bul. 11(6) :381—412.
1918a. Equipment for maintaining a flow of
oxygen-free water, and for control-
ling gas content. Ill. Lab. Nat. Hist.
Bul. 11(9) :573-5.
1918b. Ways and means of measuring the
dangers of pollution to fisheries. Ill.
Nat. Hist. Surv. Bul. 13(2) : 25-42.
Shelford, V. E., and W. P. Flint
1943. Populations of the chinch bug in the
upper Mississippi valley from 1823
to 1940. Ecology 24(4) :435—-55.
Shelford, V. E., and R. E. Yeatter
Monog.
1955. Some suggested relations of prairie
chicken abundance to physical fac-
tors, especially rainfall and solar
radiation. Jour. Wildlife Mgt. 19(2) :
233-42. :
Short, C. W.
1845. Observations on the botany of Illi-
nois, more especially in reference to
the autumnal flora of the prairies.
West. Jour. Med. and Surg., ns.,
3:185-98. [Typed copy made at the
University of Illinois from volume
borrowed from library of St. Louis
Medical Society. ]
Simmons, Marguerite
1952. Natural History Survey Library, an-
nual report, July 1, 1951-June 30,
1952. 5 pp. [Not published, but
available in University of Illinois
Library, Urbana. ]
Smith, Frank
1895a. A preliminary account of two new
Oligochaeta from Illinois. Ill. Lab.
Nat. Hist. Bul. 4(5) :138-48.
1895. Notes on species of North American
Oligochaeta. Ill. Lab. Nat. Hist. Bul.
4(8) :285-97.
1896. Notes on species of North American
December, 1958
Oligochaeta. IJ. Ill. Lab. Nat. Hist.
Bul. 4(14) :396-413+4 pls.
1900a. Notes on species of North American
Oligochaeta. III. List of species
found in Illinois, and descriptions of
Illinois Tubificidae. Ill. Lab. Nat.
Hist. Bul. 5(10) :441-58+2 pls.
1900b. Notes on species of North American
Oligochaeta. IV. On a new lum-
briculid genus from Florida, with
additional notes on the nephridial
and circulatory systems of Mesoporo-
drilus asymmetricus Smith. Ill. Lab.
Nat. Hist. Bul. 5(11) :459-78+1 pl.
State natural history surveys. Science,
n.s., 13(328) :566-8.
Notes on species of North American
Oligochaeta. V. The systematic re-
lationship of Lumbriculus (Thino-
drilus) inconstans (Smith). Ill. Lab.
Nat. Hist. Bul. 7(5) : 45-51.
Two new varieties of earthworms
with a key to described species in
Illinois. Il]. Lab. Nat. Hist. Bul.
10(8) :551-9+1 pl.
A new North American oligochaete
of the genus Haflotaxis. Ill. Nat.
Hist. Surv. Bul. 13(3) :43-8+1 pl.
An account of changes in the earth-
worm fauna of Illinois and a de-
scription of one new species. Ill.
Nat. Hist. Surv. Bul. 17(10) :347-62.
Records of spring migration of birds
at Urbana, Illinois, 1903-1922. IIl.
Nat. Hist. Surv. Bul. 19(2) :105-17.
Smith, George W.
1927. History of Illinois and her people.
Vol. 2. The American Historical
Society, Inc., Chicago and New York.
496 pp.
Smith, Lloyd L., Jr.
1949. Cooperative fishery survey of the
upper Mississippi River. Am. Fish.
Soc. Trans. for 1946, 76:279-82.
Spooner, Charles S., Jr.. and Lee E. Yeager
1942. Potential wildlife habitat on the IIli-
nois prairie and some problems of
restoration. Jour. Wildlife Met.
6(1) :44—54.
Stannard, Lewis J., Jr.
1957. The phylogeny and classification of
the North American genera of the
suborder ‘Tubulifera (Thysanop-
tera). Ill. Biol. Monog. 25. 200 pp.
Starrett, William C., and Paul G. Barnickol
1955. Efficiency and selectivity of commer-
cial fishing devices used on the Mis-
sissippi River. II]. Nat. Hist. Surv.
Bul. 26(4) :325-66.
Starrett, William C., and Perl L. McNeil, Jr.
1901.
1905.
1915.
1918.
1928.
1930.
1952. Sport fishing at Lake Chautauqua,
near Havana, Illinois, in 1950 and
1951. Ill. Nat. Hist. Surv. Biol. Notes
30. 31 pp.
Stessel, G. J., and Bert M. Zuckerman
1953. The perithecial stage of Chalara
LITERATURE CITED 231
quercina in nature.
43(2) :65-70.
Stoddard, Herbert L.
1931. ‘The bobwhite quail: its habits, pres-
ervation and increase. Charles Scrib-
ner’s Sons, New York. xxixt559 pp.
Stout, G. L.
1930. New fungi found on the Indian corn
plant in Illinois. Mycologia 22(6):
271-87.
Surber, Eugene W.
1931. Sodium arsenite for controlling sub-
merged vegetation in fish ponds. Am.
Fish. Soc. Trans. for 1931, 61:143-7.
Swingle, H. S., and E. V. Smith
Phytopathology
1939. Increasing fish production in ponds.
N. Am. Wildlife Conf. Trans. 4:
332-8.
1942. Management of farm fish ponds.
Ala. Polytech. Inst. Ag. Exp. Sta.
Bul. 254. 23 pp.
Swingle, Roger U.
1942. Phloem necrosis: a virus disease of
the American elm. U. S. Dept. Ag.
Circ. 640. 8 pp.
Tehon, Leo Roy
1924. Notes on the parasitic fungi of IIli-
nois. Mycologia 16(4) :135—42.
Three alfalfa diseases new to IIli-
nois. Ill. Acad. Sci. Trans. for 1925,
18 :203-5.
Methods and principles for interpret-
ing the phenology of crop pests. IIl.
Nat. Hist. Surv. Bul. 17(9) :321-46.
Notes on the parasitic fungi of IIli-
nois. Mycologia 25(4) :237—57.
A monographic rearrangement of
Lophodermium. Ill. Biol. Monog.
13 (4) :231-381.
Rout the weeds! Why, when and
how. Ill. Nat. Hist. Surv. Circ. 28.
34 pp. (Later issued as Circ. 34.)
Notes on the parasitic fungi of IIli-
nois. VI. Mycologia 29(4) :434—46.
1939a. Pleasure with plants. Ill. Nat. Hist.
Surv. Circ. 32. 32 pp.
Fungus growth cause of broom corn
splotches. Broom and Broom Corn
News 28(33) :13.
Two new fungi on legumes.
logia 31(5) :537-43.
New species and taxonomic changes
in the Hypodermataceae. Mycologia
31(6) :674—92.
Fieldbook of native Illinois shrubs.
Ill. Nat. Hist. Surv. Man. 3. 307 pp.
A new mucor-like fungus from plant
roots. Ill. Acad. Sci. Trans. for 1943,
36(2) :109-15.
The drug plants of Illinois. Ill. Nat.
Hist. Surv. Circ. 44. 135 pp.
Fungistatic potencies of some fluori-
nated p-benzoquinones. Science, n.s.,
114 (2973) :663-4.
Tehon, Leo R., Translator
1952a. True nature, causes, and sad effects
1925.
1928.
1933.
1935.
1937a.
1937.
19396.
1939c. Myco-
1939d.
1942.
1943.
1951a.
1951.
bo
w
bo
of the rust, the bunt, the smut, and
other maladies of wheat, and of oats
in the field. Part V of Alimurgia or
Means of rendering less serious the
dearths: proposed for the relief of
the poor. Translated from the Ital-
ian of Giovanni Targioni Tozzetti.
Phytopathological Classics 9. xxiv
+139 pp.
Tehon, Leo Roy
1952b. Fungistatic capacities of aromatic
fluorine compounds in relation to
cloth-rotting fungi. Part 3. Fluori-
nated anisoles, benzyls, benzoic acids,
biphenyls, and toluenes. AF Tech.
Rep. 6518(3). 46 pp. Wright Air
Development Center, Wright-Patter-
son Air Force Base, Ohio.
1954. Fungistatic capacities of aromatic
fluorine compounds in relation to
cloth-rotting fungi. Part 4. Fluori-
nated phenols, benzyl alcohol, and
biphenyls. AF Tech. Rep. 6518(4).
38 pp. Wright Air Development
Center, Wright-Patterson Air Force
Base, Ohio.
Tehon, L. R., and G. H. Boewe
1939. Charcoal rot in Illinois. U. S. Dept.
Ag. Plant Dis. Reptr. 23(19) :312-21.
Tehon, L. R., and Eve Daniels
1925. Notes on the parasitic fungi of IIli-
nois—II. Mycologia 17(6) :240-9.
Tehon, L. R., and E. Y. Daniels
1927. Notes on the parasitic fungi of IIli-
nois—III. Mycologia 19(3) :110-29.
Tehon, Leo R., and Hubert A. Harris
1941. A chytrid inhabiting xylem in the
Moline elm. Mycologia 33(1) :118-
29;
Tehon, Leo R., and W. R. Jacks
1933. Smooth patch, a bark lesion of white
oak. Jour. Forestry 31(4) :430-3.
Tehon, L. R., C. C. Morrill, and Robert
Graham
1946. Illinois plants poisonous to livestock.
Ill. Ag. Exp. Sta. Cire. 599. 103 pp.
Tehon, L. R., and G. L. Stout
1928. An ascomycetous leaf spot of cow-
pea. Phytopathology 18(8) :701-4.
1929. Notes on the parasitic fungi of Illi-
nois—IV. Mycologia 21(4) :180-96.
Tehon, Leo R., and Sylvia Wolcyrz
1952a. Fungistatic capacities of aromatic
fluorine compounds in relation to
cloth-rotting fungi. Part 1. Fluori-
nated quinones and phenols. AF
Tech. Rep. 6518(1). 62 pp. Wright
Air Development Center, Wright-
Patterson Air Force Base, Ohio.
1952. Fungistatic capacities of aromatic
fluorine compounds in relation to
cloth-rotting fungi. Part 2. Fluori-
nated phenols, nitrobenzenes, and
anilines. AF Tech. Rep. 6518(2).
58 pp. Wright Air Development
Telford,
1923.
1926.
Thomas,
1857.
1859a.
1859b.
1861la.
1861d.
186l1c.
1865.
1876.
[1878.]
1880.
1881.
ILtinois NatrurAL History Survey BULLETIN Vol. 27, Art. 2
Center, Wright-Patterson Air Force
Base, Ohio.
Clarence J.
Growth studies of certain bottom-
land species in southern Illinois. III.
Acad. Sci. Trans. for 1923, 16:210-3.
Third report on a forest survey of
Illinois. Ill. Nat. Hist. Surv. Bul.
16(1) :1-102.
Cyrus
Natural history of Illinois. Ill.
Teacher 3(12) :424-5.
The study of natural history. IIl.
Ag. Soc. Trans. for 1857-1858, 3:665-
70.
Orthoptera of Illinois. Ill. Ag. Soe.
Trans. for 1857-1858, 3:682-5.
Notes on Illinois insects. Ill. Ag.
Soc. Trans. for 1859-1860, 4:631-49.
Mammals of Illinois. Catalogue. Ill.
Ag. Soc. Trans. for 1859-1860, 4:651-
61.
Plan for a natural history survey.
Ill. Ag. Soc. Trans. for 1859-1860,
4:663-5.
Insects injurious to vegetation in IIli-
nois. Ill. Ag. Soc. Trans. for 1861—
1864, 5:401-68.
A list of the Orthoptera of Illinois.
Ill. Mus. Nat. Hist. Bul. 1(1) :59-69.
A list of the species of the tribe
Aphidini, family Aphidae, found in
the United States, which have been
heretofore named, with descriptions
of some new species. Ill. Lab. Nat.
Hist. Bul. 1(2) :3-16.
Temperature and rainfall as affect-
ing the chinch bug—periodicity in its
increase. Am. Ent., n.s., 1(10) :240-2.
Tenth report of the State Entomolo-
gist . . . on the noxious and beneficial
insects of the state of Illinois. III.
Ent. Rep. 10. 238+ vi pp.
Thompson, David H.
1925.
1933a.
1933.
1941.
Some observations on the oxygen re-
quirements of fishes in the Illinois
River. Ill. Nat. Hist. Surv. Bul.
15(7) :423-37.
The migration of Illinois fishes. III.
Nat. Hist. Surv. Biol. Notes 1. 25 pp.
Mimeo.
The finding of very young Polyodon.
Copeia 1933(1) :31-3.
The fish production of inland streams
and lakes. Pp. 206-17 in A sympo-
sium on hydrobiology. University of
Wisconsin Press, Madison. ix+405
pPp-
Thompson, David H., and George W. Bennett
1939a.
1939.
1939¢.
Lake management reports. 2. Fork
Lake near Mount Zion, Illinois. Ill.
Nat. Hist. Surv. Biol. Notes 9. 14 pp.
Lake management reports. 3. Lincoln
Lakes near Lincoln, Illinois. Ill. Nat.
Hist. Surv. Biol. Notes 11. 24 pp.
Fish management in small artificial
December, 1958
lakes. N. Am. Wildlife Conf. Trans.
4:311-7.
Thompson, David H., and Francis D. Hunt
1930. The fishes of Champaign County: a
study of the distribution and abun-
dance of fishes in small streams. III.
Nat. Hist. Surv. Bul. 19(1) :5-101.
Thomson, G. H.
1913. Protection of the
Am. Fish. Soc.
42:171-3.
Trumbower, John A.
1934. Control of elm leaf spots in nurseries.
Phytopathology 24(1) : 62-73.
Turner, J. B.
1859. Microscopic
Trans. for
Ulffers, H. A.
1855. Mollusca of
Trans. for
undersized fish,
Trans. for 1912,
insects. Ill. Ag. Soc.
1857-1858, 3:644—50.
southern Illinois. Ill.
1853-1854,
Underwood, Lucien M.
1886. List of the described species of fresh
water Crustacea from America, north
of Mexico. II]. Lab. Nat. Hist. Bul.
2(5) :323-86.
Van Cleave, Harley J.
1919. Acanthocephala from the _ Illinois
River, with descriptions of species
and a synopsis of the family Neoechi-
norhynchidae. Ill. Nat. Hist. Surv.
Bul. 13(8) :225-57+7 pls.
1930. Stephen Alfred Forbes as a scientist.
Pp. 24-8 in Memorial of the funeral
services for Stephen Alfred Forbes,
Ph.D., LL.D. University of Illinois
Press, [Urbana]. 40 pp.
1947. A history of the Department of Zool-
ogy in the University of Illinois.
Bios 18(2) :75-97.
Vasey, George
1859. Mosses of Illinois. Ill. Ag. Soe.
Trans. for 1857-1858, 3:676-9.
1861. Additions to the flora of Illinois.
Ill. Nat. Hist. Soc. Trans. 2nd ed.
Ser. 1, 1:139-43.
Vasey, George, Editor of Botanical Depart-
ment
1870a. New plants.
2(9) :288.
1870. Maritime plants of the Great Lakes
and the interior. Am. Ent. and Bot.
Am. Ent. and _ Bot.
2(11) :342-4.
Vestal, Arthur G.
1913. An associational study of Illinois
sand prairie. Ill. Lab. Nat. Hist. Bul.
10(1) :1-96+5 pls.
Vohs, Paul A., Jr.
1957. A combination salad _ for
Ill. Wildlife 13(1) :3-5.
Walsh, Benj. D.
wildlife.
1861. Insects injurious to vegetation in IIli-
nois. Ill. Ag. Soc. Trans. for 1859-
1860, 4:335-72.
1863. List of the Pseudoneuroptera of IIli-
LITERATURE CITED
233
nois contained in the cabinet of the
writer, with descriptions of over
forty new species, and notes on their
structural affinities. Acad. Nat. Sci.
Phila. Proc. for 1862:361-402.
1864a. Notes by Benj. D. Walsh. Ent. Soc.
Phila. Proc. for 1863-1864, 2(3) :182-
22,
18644. On the pupa of the ephemerinous
genus Baetisca Walsh. Ent. Soc.
Phila. Proc. 3:200-6.
[ Walsh, Benj. D.]
1866. The new potato bug. Pract. Ent.
2(2) :13-6.
Walsh, Benj. D.
1868a. An address to Southern II]linois Fruit
Growers’ Association. II]. Hort. Soc.
Trans. for 1867, n.s., 1:143-4.
18684. First annual report of the Acting
State Entomologist. Append. to III.
Hort. Soc. Trans. for 1867. 103 pp.
+2 pis.
Walsh, Benj. D., and Charles V. Riley, Editors
1868a. Salutatory. Am. Ent. 1(1) :1-3.
1868b. Hogs vs. bugs. Am. Ent. 1(1) :3-6.
1869. The asparagus beetle. Am. Ent.
1(6) :114—-5.
Walters, C. S., B. M. Zuckerman, and W. L.
Meek
1955. The effect of oak wilt on the cold-
soak treatability of oak fence posts.
Jour. Forestry 53(5) :356-8.
Wandell, Willet N.
1948. Agricultural and wildlife values of
habitat improvement plantings on the
Illinois black prairie. N. Am. Wild-
life Conf. Trans. 13:256-69.
Ward, Henry B.
1930. Stephen Alfred Forbes—a_ tribute.
Science, n.s.. 71(1841) :378—-81.
Weed, Clarence M.
1890. A descriptive catalogue of the Pha-
langiinae of Illinois. Ill. Lab. Nat.
Hist. Bul. 3(5) :79-97.
1891. Sixth contribution to a knowledge of
the life history of certain little-known
Aphididae. II]. Lab. Nat. Hist. Bul.
3(12) :207-14.
Weed, Clarence M., and Ned Dearborn
1903. Birds in their relations to man. J.
B. Lippincott Co., Philadelphia. viii
+380 pp.
Weiss, Harry B.
1936. The pioneer century of American
entomology. Published by the au-
thor, New Brunswick, N. J. 320 pp.
Mimeo.
Wells, Morris M.
1918. The reactions and_ resistance of
fishes to carbon dioxide and carbon
monoxide. Ill. Lab. Nat. Hist. Bul.
11(8) :557-71.
West, James A.
1910. A study of the food of moles in IIli-
nois. Ill. Lab. Nat. Hist. Bul. 9(2):
14-22.
234
Wickliff, E. L.
1933. A summary of fisheries
Am. Fish. Soc. Trans. for
63 :257-64.
Wiebe, A. H.
1929. The effects of various fertilizers on
plankton production. Am. Fish. Soc.
Trans. for 1929, 59:94-101.
Wilber, C. D., Secretary
1861a. Transactions of the Illinois Natural
History Society for the year 1860. III.
Ag. Soc. Trans. for 1859-1860, 4:533-
675.
Wilber, C. D.
1861b. Mastodon giganteus. Ill. Ag. Soc.
Trans. for 1859-1860, 4:587—92.
1861c. Museum of the Illinois State Natural
History Society. Ill. Ag. Soc. Trans.
for 1859-1860, 4:673-5.
Wilber, C. D., Secretary
1861d. Transactions of the Illinois Natural
research.
1933,
History Society. 2nd ed., Vol. I, Ser.
I. Springfield. 194 pp.
Wolf, John, and Elihu Hall
1878. A list of the mosses, liverworts and
lichens of Illinois. IJ]. Lab. Nat.
Hist. Bul. 1(2) :18-35.
Wood, Frank Elmer
1910a. A study of the mammals of Cham-
paign County, Illinois. Ill. Lab. Nat.
Hist. Bul. 8(5) :501-613+3 pls.
19104. On the common shrew-mole, Scalo-
pus aquaticus machrinus (Rafi-
nesque), in Illinois. Ill. Lab. Nat.
Hist. Bul. 9(1) :1-13.
Woodworth, Charles W.
1887. Jassidae of Illinois. Part I. Ill. Lab.
Nat. Hist. Bul. 3(2) :9-37+3 pls.
Yeager, Lee E.
1941a. A contribution toward a bibliogra-
phy on North American fur animals.
Ill. Nat. Hist. Surv. Biol. Notes 16.
209 pp. Mimeo.
1941b. Wildlife management on coal
stripped land. N. Am. Wildlife
Conf. Trans. 5:348-53.
Coal-stripped land as a mammal
habitat, with special reference to fur
1942.
I-ttinois NATuRAL History SurvEY BULLETIN
Vol. 27, Art. 2
animals. Am. Midland Nat. 27(3):
613-35.
1943. Fur production and management of
Illinois drainage system. N. Am.
Wildlife Conf. Trans. 8:294-301.
1945. Capacity of Illinois land types to
produce furs. N. Am. Wildlife Conf.
Trans. 10:79-86.
1949. Effect of permanent flooding in a
river-bottom timber area. III. Nat.
Hist. Surv. Bul. 25(2) :33-65.
Yeager, Lee E., and Harry G. Anderson
1944. Some effects of flooding and water-
fowl concentration on mammals of a
refuge area in central Illinois. Am.
Midland Nat. 31(1) :159-78.
Yeager, Lee E., and William H. Elder
1945. Pre- and post-hunting season foods
of raccoons on an Illinois goose ref-
uge. Jour. Wildlife Mgt. 9(1) : 48-56.
Yeager, Lee E., and R. G. Rennels
1943. Fur yield and autumn foods of the
raccoon in Illinois River bottom
lands. Jour. Wildlife Mgt. 7(1) :45-
60.
Yeatter, Ralph E.
1943. The prairie chicken in Illinois. Ill.
Nat. Hist. Surv. Bul. 22(4) :377-416.
Bird dogs in sport and conservation.
Ill. Nat. Hist. Surv. Cire. 42. 64 pp.
Effects of different preincubation
temperatures on the hatchability of
pheasant eggs. Science, ns. 112
(2914) :529-30.
Is the prairie chicken doomed? Ill.
Wildlife 12(2) :8-9.
Yeatter, Ralph E., and David H. Thompson
1952. Tularemia, weather, and rabbit pop-
ulations. Ill. Nat. Hist. Surv. Bul.
25 (6) :351—-82.
Zuckerman, Bert M., and E. A. Curl
1953. Proof that the fungus pads on oak
wilt-killed trees are a growth form
of Endoconidiophora fagacearum.
Phytopathology 43(5) :287-8.
Zuckerman, Bert M., and P. F. Hoffman
1953. C** as a tool for the study of the oak
wilt fungus. Phytopathology 43(9):
490.
1948.
1950.
1957.
——— ss
Se ee eee ee ee
Uy
RPh by 2
hats
t
Cet
SPAN
Some Recent Publications of the
ILtrnois NaturAL History Survey
BULLETIN
Volume 26, Article 1.—The Mayflies, or Ephem-
eroptera, of Illinois. By B. D. Burks. May,
1953. 216 pp., frontis., 395 figs., bibliog. $1.25.
Volume 26, Article 2.—Largemouth Bass in
Ridge Lake, Coles County, Illinois. By
George W. Bennett. November, 1954. 60
pp., frontis., 15 figs., bibliog.
Volume 26, Article 3.—Natural Availability
of Oak Wilt Inocula. By E. A. Curl. June,
1955. 48 pp., frontis., 22 figs., bibliog.
Volume 26, Article 4.—Efficiency and Selec-
tivity of Commercial Fishing Devices Used
on the Mississippi River. By William C.
Starrett and Paul G. Barnickol. July,
1953. 42 pp., frontis., 17 figs., bibliog.
Volume 26, Article 5.—Hill Prairies of IIli-
nois. By Robert A. Evers. August, 1955.
80 pp., frontis., 28 figs., bibliog.
Volume 26, Article 6.—Fusarium Disease of
Gladiolus: Its Causal Agent. By Junius L.
Forsberg. September, 1955. 57 pp., frontis.,
22 figs., bibliog.
Volume 27, Article 1.—Ecological Life History
of the Warmouth. By R. Weldon Larimore.
August, 1957. 84 pp., color frontis., 27 figs.,
bibliog.
CIRCULAR
32.—Pleasure With Plants. By L. R. Tehon.
July, 1958. (Fifth printing, with revisions.)
32 pp., frontis., 8 figs.
42.—Bird Dogs in Sport and Conservation.
By Ralph E. Yeatter. December, 1948. 64
pp., frontis., 40 figs.
45.—Housing for Wood Ducks. By Frank C.
Bellrose. February, 1955. (Second print-
ing, with revisions.) 47 pp., illus., bibliog.
46.—Illinois Trees: Their Diseases. By J.
Cedric Carter. August, 1955. 99 pp.,
frontis., 93 figs. Single copies free to IIli-
nois residents; 25 cents to others.
47.—Illinois Trees and Shrubs: Their Insect
Enemies. By L. L. English. May, 1958. 92
pp., frontis., 59 figs. index. Single copies
free to Illinois residents; 25 cents to others.
List of available publications mailed on request.
Single copies of ILLINoIs NATURAL History Survey publications for which no price is listed
will be furnished free of charge to individuals until the supply becomes low, after which —
nominal charge may be made. More than one copy of any free publication may be o ia
without cost by educational institutions and official organizations within the State of iin
prices to others on quantity orders of these publications will be quoted upon request.
Address orders and correspondence to the Chief
Inurnois Natura History SuRvEY
Natural Resources Building, Urbana, Illinois
Payment in the form of money order or check made out to State Treasurer of Illinois,
Springfield, Illinois, must accompany requests for those publications on which a price is set. i
BIOLOGICAL NOTES
29.—An Inventory of the Fishes of Jordana
Creek, Vermilion County, Illinois. ris Rig
Weldon Larimore, Quentin H. a
and Leonard Durham. August, 1952,
pp., 25 figs., bibliog. (
30.—Sport Fishing at take Chautauqua, near ;
Havana, Illinois, in 1950 and 1951. By
William C. Starrett and Perl L. McNeil,
Jr. August, 1952. 31 pp., 22 figs. bibliog.
31—Some Conservation Problems of the i
Great Lakes. By Harlow B. Mills. ia
ber, 1953. (Second printing.) 14 pp., a
bibliog. a
33—A New Technique in Control of the
House Fly. By Willis N. Bruce. Decem-
ber, 1953. 8 pp., 5 figs.
34.—White-Tailed Deer Populations in Ili.
nois. By Lysle R. Pietsch. June, 1954, 24
pp., 17 figs., bibliog. es
35——An Evaluation of the Red Fox. By —
Thomas G. Scott. July, 1955. (Second
printing.) 16 pp., illus., bibliog.
36—A Spectacular Waterfowl Migratio .
Through Central North America, By Frank —
C. Bellrose. April, 1957. 24 pp., 9 figs, =
37.—Continuous Mass Rearing of the Euro-
pean Corn Borer in the oar By
Paul Surany. May, 1957. 12 pp., 7 figs, %:
bibliog.
38.—Ectoparasites of the Cottontail Rabbit ing
Lee County, Northern Illinois. By Lewis J. ©
Stannard, Jr., and Lysle R. Pietsch. June, —
1958. 20 pp., 14 figs., bibliog.
39.—A Guide to Aging of Pheasant Embryos. _
By Ronald F. Labisky and James F. oe
4 pp., illus., bibliog.
MANUAL
3.—Fieldbook of Native [llinois Shrubs. By
Leo R. Tehon. December, 1942. 307 pp.,
4 color pls., 72 figs., glossary, index. $1.75
4.—Fieldbook of Illinois Mammals. By Donald —
F. Hoffmeister and Carl O. Mohr. June,
1957. 233 pp., color frontis., 119 figs., glos- —
sary, bibliog., index. $1.75. :
ILLINOIS NATURAL HISTORY SURVEY
Bulletin Printed by Authority of Ce
the State of Illinois
Lead Poisoning
as a Mortality Factor
in Waterfowl Populations
FRANK C. BELLROSE
STATE OF ILLINOIS e Wim G. Srratron, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binks, Directer
NATURAL HISTORY SURVEY DIVISION e¢ Hartow B. Muts, Chief
MAT IOKS
Pers Uae.
jbo
MeL tINOIS. NATURAL HISTORY SURVEY
Bulletin
Volume 27, Article 3 aE
Printed by Authority of
May, 1959 the State of Illinois
Lead Poisoning
as a Mortality Factor
in Waterfowl Populations
Poet K- ©. BELLROSE
STATE OF ILLINOIS e WILLIAM G. STRATTON, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION e Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION @ Hartow B. Mitts, Chief
Urbana Illinois
STATEOF TLEINOIs
Wittiam G. Srrarron, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
Vera M. Binks, Director
BOARD OF NATURAL RESOURCES AND CONSERVATION
Vera M. Binks, Chairman;
Ph.D., D.Sc., Chemistry ; Rosert H.
President of the University of Illinois,
A. E. Emerson, Ph.D., Biology; Watter H. Newnuouse, Ph.D., Ce Rocer Apams,
ANDERSON, ave I., Engineering; W. L.
Dretyre W. Morais,
Everitt, E.E., Ph.D., Representing the
Ph.D.. President of Southern Illinois University
NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois
SCIENTIFIC AND TECHNICAL STAFF
Hartow B. Muixts,
Ph.D., Chief
Bessie B. East, M.S., Assistant to the Chief
Section of Economic bee rs
Georce C. Decker, Ph.D., Principal Scientist and Head
Jo LH. J BIGGER, IVML.0. Entomologist
L. L. Encuisx, Ph_D., Entomologist
Wiis N. Bruce, Ph.D., Associate Entomologist
Norman Gannon, Ph.D., Associate Entomologist
W. H. Lucxkmann, Ph.D., Associate Entomologist
Ronatp H. Meyer, M.S., Assistant Entomologist
Joun D. Pascuxe, Ph.D., Assistant Entomologist
Joun P. Kramer, Ph.D., Assistant Entomologist
Rosert Snetsincer, M.S., Field Assistant
Carot Morcan, B.S., Laboratory Assistant
Eucene M. Bravi, M.S., Research Assistant
Ricuarv B. Dysart, B.S., Technical Assistant
Recinatp Roserts, A.B., Technical Assistant
James W. Sanrorp, B.S., Technical Assistant
Eart Stapecpacuer, B.S., Technical Assistant
Sue E. Warkins, Technical Assistant
H. B. Perry, Ph.D
Srevenson Moore, III,
Entomology*
Zenas B. Noon, Jr., M.S., Research Assistant*
Crarence E, Wuire, B.S., Research Assistant*
Joun Artuur Lowe, M.S., Research Assistant*
fs pela Horrman, B.S., Research Assistant*
Cartos A. Wuire, B.S., Research Assistant*
Roy E. McLaucuuin, B.S., Research Assistant*
Costas Kousxorexas, M.S., Research Assistant*
Louise Zincrone, B.S., Research Assistant*
Mary E. Mann, R.N., Research Assistant*
Ph.D., Extension Specialist in
Section of Faunistic Surveys and Insect Identification
H. H. Ross, Ph.D., Systematic Entomologist and Head
Mitton W. Sanperson, Ph.D., Taxonomist
Lewis J. STANNARD, Jr., Ph.D., Associate Taxonomist
Puitie W. Smirn, Ph. Di; Associate Taxonomist
Leonora K. Guoyp, M.S., Assistant Taxonomist
H. B. CunnincHam, MS., Assistant Taxonomist
Epwarp L. Mocxkrorp, MS., Technical Assistant
Tueima H. Overstreet, Technical Assistant
Section of Aquatic Biology
Grorce W. Bennett, Ph.D., Aquatic Biologist and Head
WiruraM C. seas Ph.D., Aquatic Biologist
R. W. Larimore, Ph. Aquatic Biologist
Daviv H. Bucx, Ph. oe " Associate Aquatic Biologist
Rosert C. Hirtisran, Ph.D., Associate Biochemist
Donatp F. Hansen, Ph.D., Assistant Aquatic Biologist
Wiruram F. CHILpers, MS., Assistant Aquatic Biologist
MariFran Martin, Technical Assistant
Joun C. Crarrey, B.S., Field Assistant
, Extension Specialist in Entomology*
Section of Aquatic Biology—continued
Ricnarp E. Bass, Field Assistant
Rosert D. Crompton, Field Assistant
Arnotp W. Fritz, B.S., Field Assistant*
Daviw J. McGinty, Field Assistant*
Section of Applied Botany and Plant Pathology
J. Cepric Carter, Ph.D., Plant Pathologist and Head
J. L. Forssere, Ph.D., Plant Pathologist
G. H. Borewe, M.S., Associate Botanist
Roperr A. Evers, Ph.D., Associate Botanist
Rospert Dan Neeny, Ph.D., Associate Plant Pathologist
E. B. Himeuicx, M.S., Assistant Plant Pathologist
Wa ter Hartstirn, Ph.D., Assistant Plant Pathologist
D. F. Scuoenewetss, Ph.D., Assistant Plant Pathologist
Rovenia F. Firz-Geraxp, B.A., Technical Assistant
Section of Wildlife Research
Tuomas G. Scott, Ph.D., Game Specialist and Head
Ratpu £. Yeatrer, Ph.D., Game Specialist
Cart O. Monr, Ph.D., Game Specialist
F. C. Berirose, B.S., Game Specialist
H. C. Hanson, Ph.D., Associate Game Specialist
Ricuarp R. Graser, Ph.D., Associate Wildlife Specialist
Ronatp F. Lasisxy, M.S., Assistant Wildlife Specialist
Frances D. Rossins, B.A., Technical Assistant
Vireinta A. Lancpon, Technical Assistant
Howarn Crum, Jr., Field Assistant
Joun L. Roseserry, B.S., Technical Assistant
Rexrorp D. Lorn, D.Sc., Project Leader*
Freperick GREELEY, Ph.D., Project Leader*
Guien C. Sanpverson, M.A., Project Leader*
Jacx A. Exuis, M.S., Assistant Project Leader*
Tuomas R. B. Barr, M.V.Sc., M.R.C.V.S., Research
Assistant*
Bossie Joe Verts, M.S., Field Mammalogist*
Erwin W. Pearson, M.S., Field Mammalogist*
Keitu P. Daurutin, Assistant Laboratory Attendant*
Gary P. Imex, Assistant Laboratory Attendant*
Section of Publications and Public Relations
James S. Ayars, B.S., Technical ‘Editor and Head
Brancue P. Younc, B.A., Assistant Technical Editor
Diana R. Braverman, B.A., Assistant Technical Editor
Wixruiam E. Crarx, Assistant Technical Photographer
MarcGueErite VERLEY, Technical Assistant
Technical Library
Rutw R. Warrick, B.S., B.S.L.S., Technical Librarian
Nett Mires, M.S., B.S.L.S., Assistant Technical
Librarian
CONSULTANTS: Herretotocy, Hosarr M. Smirn, Ph.D., Professor of Zoology, University of Illinois; Parasito.ocy,
Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University of Illinois;
WuDLiFE RESEARCH, WILLARD D. Kuimstra, Ph.D.,
Wildlife Research, Southern Illinois University.
*Employed on_co-operative projects with one of several agencies:
United States Army
Extension Service, Illinois Department of Conservation,
Assistant Professor of Zoology and Director of Co-operative
University of Illinois, Illinois Agricultural
Surgeon General’s Office, United States
Department of Agriculture, United States Fish and Wildlife Service, United States Public Health Service, and others.
This paper is a contribution from the Section of Wildlife Research.
(86180—5,500—10-58)
CONTENTS
Sate SMSEV TVET RUE Tee Nan) iG ea ecient eat Soe A Lei laie MDT peewee SAS 236
Perret ONIN ECB So scons c'- pc leeed Wa WNe fe eicgc. sveleinaie 0 agit serene e OM lean eee ale 236
i APM MON AIS Meer t cbt on MIS Rs ters alata Syncdy tgs seiore eas Boece ade ahd care hc calas dR eae TIO 238
aa eS TON IO) =O) SES Nae eras oe Shah MAST Te Pe as alo Mave ce eon © Gudid shown oe Oia Die Bho Agnes a ewe 239
C2 SBVI ae: “LENS GENEL one AE ee ne ee eee Sea aPC eT | 239
Bp irsercstenniee ll yeu tres 5 Se rite ea pica iss nee ecedtan cyehe ste Sua. te Sark aisle he reuinalatetale ree tee 242
MirerLinctacd MPL unacety ete ci. ach cs S. rk Mee a nitoahy o Mba a ice Wrckw a, Plats deals ayk Bl eRe 243
SRLS OTe GaN Gaga ae RN eee cn fear ROE en Se Re a are ee nee er 244
RESUME) Kiso uA. was tps atti. cob relin s< Gah os ig atece woatausln teu dale aid maaan ee ae 245
ee ReatT SMe eo alee 1G) the tne ae Pe Wye oh a ot a aa, v cl SOs ala a-aagbane a dre et ee ewe ine a 246
Mpeeresme ViFEClC OID ie = ONES. Ss oaiiis y civ danse ems Riswe Sue 4 eee vee Worne elites vs Searels E cans 247
Ifcidencexot iuead) Ohnotun Wies OES. io .utce< . dco ade Dae + sod ee asics aver eedaes 247
LTP ATLANTIS Oe | Da ee Se, RON PS 249
PRGESTED WEADeorOr IN). IVIKGRATING DUCKS... 202s 6 os gt aye bee se ee ba ole se tee ome 254
Dhami ivie- tapped OUCKS.... Semis nee bsg as dels or oc Sate a vba} lermeie base Mae 3 eee 254
permeates Lao men nye PMPeN S.-i. a.ciec 0 sacn's Sp cus|s i= ovo 4 Hticie ae alle wien ole oe oleate ie 258
Marvations in ohot Incidence Amonopopecies 2. 2...ok sae ve tae eels oes ele daa sees 259
Real Weriations: dn oot IMiCiIdenCe.); < ciiree isle < clsoo 0 2 cde Buje pide wo sle ee 261
EPEMouicuy aniations: ineolot. Uncidence:..3 «air. e ass ws sos ks wate aa ae cts Rie brie 265
EHEIENCEMOL OVATIONS, ONOE ILEVEIS), Hic, ctasvele cco cges a dlnca oelh pevelam@ ome mapas, sie a 268
Pear VV ILD MALLARDS: WOSED AND) RELEASED: ...2.5¢,6¢ h0 0004 0% ¢¢ 050 h ele cgee osles 269
Pirectsat lmeadvon Varlnerability to Hunting. os06. 20.202 fee cee eee dee owe oe oe 270
Pifecumisiceadcon: Vireration. inate’... $i cr Wei a. 00/0 ott Pate eee 6 Oe aaa 272
Piect of lead on Yeat-of-bandine Mortality Rate: .....2.. 0.020. éesca eect eee 274
RmeR eT rGM ERAT OUSONT Nei iy 2) afcecacers, <s/acec es eb. vt Gear ola ¥ aie bo 9 ce wie Oeirioveiele oe. ear 276
2 SRE DESO 2 Br eee Re a er enn ery Se are eer eee Pine 279
SR is VO See Wee TY Irs SAF Bali, age Daaitsisy oR A ae Ge Wes ae Rael ans. Se 12 on aval sine, oie 283
“CINE URS ES gota BS a a abe an ys n-ne Oe er are re a 287
Photographs not otherwise credited are by William E. Clark or by Charles L. Scott.
A few of the 2,000 wild mallards that were victims of a lead poisoning outbreak near
Grafton, Illinois, in January, 1948. (Photograph from Western Cartridge Company.)
ie
Lead Poisoning as a Mortality Factor
in Waterfowl Populations
“Pos mortality resulting from lead
poisoning in populations of wild
waterfowl has been a cause of con-
cern to conservationists for many years.
This concern has grown out of the knowl-
edge that lead poisoning is of common oc-
currence among waterfowl, that this poi-
soning results from the ingestion of lead
by the birds in their feeding, and that
large numbers of lead pellets fired from
the guns of hunters lie in lakes and
marshes visited by waterfowl.
Phillips & Lincoln (1930:166), over
two decades ago, stated: “From this ac-
count it will be seen that lead poisoning
due to eating shot is of common occur-
rence, and it seems reasonable to presume
that the disease will continue and even
increase in the great ducking marshes of
the country. The ultimate conclusions as
to its effect upon the supply of waterfowl
are hazardous to imagine.” A few years
later Dr. E. C. O’Roke of the Univer-
sity of Michigan was quoted in Michigan
Waterfowl Management (Pirnie 1935:
75-6) as follows: “Considering the enor-
mous quantity of lead that there must be
in the vicinity of blinds that have been
shot over for decades, it is reasonable to
conclude that the potential danger from
lead poisoning is great and should be con-
sidered in any waterfowl management
program. In the writer’s opinion lead poi-
soning is the disease which takes the
greatest toll of adult ducks in this section
of the country.”
This theme was reiterated by Cottam
(1949 :339-40) who, in discussing fur-
ther needs in wildlife research, suggested
that “direct and indirect effects of lead
shot in the digestive tracts of birds may
be an exceedingly important stumbling
block in the restoration of waterfowl. At
the close of the hunting season live birds
are carrying in their bodies an alarming
amount of lead, and this condition may be
much more widespread than we _ have
FRANK C. BELLROSE
realized. There is urgent need to ascer-
tain the effects of the lead shot used in
hunting.”
These remarks point up the generally
recognized need for further appraisals of
the problem, which was brought home to
officials of the Illinois Natural History
Survey and Western Cartridge Company
(the latter now the Winchester-Western
Cartridge Division of Olin Mathieson
Chemical Corporation) at the time of a
publicized die-off of wild ducks, frontis-
piece, near Grafton, Illinois, in January
of 1948 (Jordan & Bellrose 1951:10-1).
As a result of a common interest in the
problem of lead poisoning in waterfowl,
the two groups supported a joint research
project embracing the following objec-
tives: (1) evaluation of losses from lead
poisoning in wild waterfowl, (2) in-
vestigation of lead alloys and other metals
as materials for possible use as nontoxic
shot, and (3) determination of the phys-
iological effects of lead poisoning in wa-
terfowl.
The present paper is devoted primarily
to the evaluation of losses resulting from
lead poisoning in wild waterfowl popula-
tions. wo reports have been published
which presented preliminary findings on
this subject (Bellrose 1951; Jordan &
Bellrose 1951). Efforts to develop a non-
toxic shot were treated in a paper dealing
with the value of various shot alloys in
relation to lead poisoning (Jordan &
Bellrose 1950); additional data on this
subject are presented herein. Findings as
to the physiological effects of lead poison-
ing on captive waterfowl have been dis-
cussed in a paper by Jordan & Bellrose
C1951):
The approach toward evaluating the
importance of lead poisoning in wild
waterfowl was threefold: (1) appraisal
of the incidence and magnitude of water-
fowl die-offs resulting from lead poison-
ing, (2) appraisal of the incidence of
[235]
236 Intinois NaturaAL History SurvEY BULLETIN
ingested lead shot among waterfowl popu-
lations in fall and early winter, and (3)
appraisal of waterfowl losses resulting
from the ingestion of various quantities of
lead shot per bird.
ACKNOWLEDGMENTS
The writer is most grateful to the
many persons in various parts of the
North American continent who furnished
material and data. Without their aid, it
would have been impossible to appraise
the importance of lead poisoning on such
an extensive basis.
The sources of much of the informa-
tion outside of Illinois are acknowledged
in the text or tables. However, the
sources of material and data related to
the occurrence of lead shot in waterfowl
gizzards have been so numerous as to
make such acknowledgment cumbersome.
Acknowledgment is made here to those
persons who sent 100 or more waterfowl]
gizzards for examination: Harold M.
Swope, Colorado; E. B. Chamberlain,
Jr., Florida; William P. Baldwin, Jr.,
Georgia and South Carolina; Robert L.
Salter, Idaho; James D. McCall and
Russell E. Mumford, Indiana; Rich-
ard K. Yancey and Charles W. Bosch,
Louisiana; Howard L. Mendall, Maine;
Gordon T. Nightingale and Dave Grice,
Massachusetts; Forrest B. Lee, Minne-
sota; Harvey Miller, Nebraska; Fred E.
Wright, Nevada; T. Stuart Critcher and
Yates M. Barber, Jr., North Carolina;
Brandt V. Hjelle, North Dakota; Wil-
liam B. Morse, Oregon; Ray Murdy and
Clair T. Rollings, South Dakota; J. R.
Singleton, Texas; Allen G. Smith, Utah.
The following biologists contributed
data on the incidence of ingested lead shot
found in waterfowl gizzards examined
primarily for food contents: lan McT.
Cowan, British Columbia; Carol M. Fer-
rel and Howard R. Leach, California;
E. B. Chamberlain, Jr., Florida; Rich-
ard K. Yancey, Louisiana; Howard L.
Mendall, Maine; Leroy J. Korschgen
and Charles E. Shanks, Missouri; Donald
D. Foley, New York; T. Stuart Critcher,
North Carolina; Charles K. Rawls, Jr.,
Tennessee; Allen G. Smith, Utah; Rob-
ert G. Jeffrey and Charles F. Yocom,
Washington.
Vol. 27, Art. 3
Many persons provided information on
waterfowl die-offs resulting from lead
poisoning. I especially wish to thank
Richard E. Griffith, John J. Lynch,
John W. Perkins, and Edward B. Davis
of the United States Fish and Wildlife
Service, and Richard K. Yancey and
Morton M. Smith of the Louisiana Wild
Life and Fisheries Commission for their
excellent co-operation.
Edwin R. Kalmbach and Arnold L.
Nelson of the United States Fish and
Wildlife Service provided suggestions and
unpublished reports on lead poisoning in
waterfowl. Johnson A. Neff of the same
agency submitted an unpublished report
on band recoveries from experimental
mallards, some untreated and some dosed
with stx No. 6 shot pellets each, near
Denver, Colorado.
Dr. Harlow B. Mills, Chief of the Illi-
nois Natural History Survey, and the
late Charles H. Hopkins and Ray
Holmes, both of Olin Mathieson Chemi-
cal Corporation, who initiated this study
as a result of their interest in a die-off of
wild ducks near Grafton, Illinois, in
1948, continued their interest and aid
throughout the study. Dr. Thomas G.
Scott, Head of the Survey’s Wildlife Re-
search Section, and Mrs. Frances Rob-
bins, Dr. Ralph E. Yeatter, and Dr.
Carl O. Mohr, all of that section, gave
many helpful suggestions which improved
both the study and the paper. John C.
Dear and Charles E. Gillham of the Olin
Mathieson Chemical Corporation helped
many times in many ways. James S. Ayars
of the Natural History Survey edited the
manuscript.
Without the financial assistance pro-
vided by Olin Mathieson Chemical Cor-
poration, much of this study would have
been impossible.
LEAD POISONING DIE-OFFS
The most dramatic expressions of lead
poisoning in waterfowl are die-offs in
which large numbers of birds in relatively
small areas perish in short periods of
time. Most of those persons who are se-
riously concerned about lead poisoning
among waterfowl have been convinced of
the importance of the malady through
witnessing one or more die-offs. Because
May, 1959 BELLROSE: LEAD PoIsONING IN WATERFOWL 237
of its emotional impact on any person Three approaches have been made by
who sees it, a waterfowl die-off is an the author of this paper in evaluating the
event that is remembered and chronicled importance of die-offs among waterfowl
for a number of years. in the United States: (1) a study of the
Fig. 1.—Opened duck gizzards and the ingested lead shot they contained. Black spots on
the horny linings of the gizzards mark areas of tissue destruction by lead salts.
Fig. 2—Two mallard stomachs: the lower one from a lead-free duck, the upper from a
lead-poisoned duck. The glandular stomach attached to the gizzard of the lead-poisoned mallard
shows impaction of small grains. The impaction of food resulting from malfunctioning of the
gizzard is one of the symptoms of lead poisoning in waterfowl.
238
literature, (2) personal on-the-spot in-
vestigations of die-offs in Illinois and
Louisiana, and (3) a canvass of state and
federal conservation agencies for recent
records of lead poisoning outbreaks among
waterfowl.
In studying several large outbreaks of
lead poisoning in Illinois, 1940-1954, and
at Catahoula Lake, Louisiana, 1953, the
author and his associates undertook a tally
of all dead and dying ducks found and of
feathers marking the demise of birds.
Rough compensations were made for areas
not covered and for the time of each sam-
pling in relation to the period of the out-
break. An estimate was made of the duck
population in each area.
Samples of dead and dying ducks were
collected. These ducks were sexed, aged,
weighed, and fluoroscoped. Fluoroscopic
procedure was similar to that described
by Jordan & Bellrose (1950:158) and
by Bellrose (1953:341). Examinations
were made of lead shot pellets in gizzards
of a number of dead ducks and were
found to agree closely with fluoroscopic
findings. Gizzards from _ lead-poisoned
ducks are shown in figs. 1 and 2.
Early Die-Offs
Records of lead poisoning in North
American waterfowl date back to the lat-
ter half of the nineteenth century. From
remarks made by Phillips & Lincoln
(1930:164), it is assumed that lead poi-
soning in waterfowl was known at least
as early as 1874. According to them, the
March, 1894, issue of the American Field
carried a note reporting that two lots of
ducks which were unfit for food (pre-
sumably as a result of lead poisoning)
were seized at Galveston, Texas. These
ducks had been taken at Stephenson Lake,
where the disease had been noted for 20
years.
More than 60 years ago, George Bird
Grinnell (1894:112) and E. Hough
(1894:117) reported in Forest and
Stream on some of the effects of lead poi-
soning on waterfowl as determined from
observations made during the winter of
1893-94. A few years later, Grinnell
(1901:598-601), in addition to review-
ing his earlier account on the appearance
and behavior of a sick goose and a sick
swan at Currituck Sound, North Caro-
Intinors Natura History Survey BULLETIN
Vol. 27, Art. 3
lina, stated that lead poisoning occurred
among waterfowl in Texas at Galveston,
at Stephenson Lake, and on Lake Sur-
prise.
A half century ago, Bowles (1908:
312-3) recorded the loss of a number of
mallards (Anas platyrhynchos) from lead
poisoning on the “Misqually”’ (presumably
Nisqually) Flats of Puget Sound, Wash-
ington. McAtee (1908:472) in the same
year gave an account of lead poisoning in
canvasbacks (A ythya valisineria) at Lake
Surprise, Texas.
Wetmore (1919:2) reported that sev-
eral whistling swans (Olor columbianus)
from Back Bay, Virginia, were examined
by the U. S. Biological Survey in Janu-
ary of 1915. Twenty-two to 45 shot pel-
lets were found in the gizzard of each
swan, indicating that the birds had been
affected by lead poisoning. He reported
also that during the summers of 1915 and
1916 in the Bear River marshes of Utah
many mallards and pintails (Anas acuta)
were affected by lead poisoning. “These
ducks were found in the period June—
September, and, although many died, the
total was insignificant as compared with
losses from other causes in the Bear River
marshes.
In discussing lead poisoning, Phillips
& Lincoln (1930:165-6) recorded an
instance in which “thousands” of ducks
were reported dying at Hovey Lake, In-
diana, in February, 1922, from an un-
known malady that was later diagnosed
as lead poisoning. The report they found
to be “much exaggerated.” They ob-
served that ‘‘Possibly the most serious con-
dition exists in Louisiana, where duck
mortality from this cause may sometimes
be further complicated by internal para-
sites and possibly at times by lack of
food”; that newspapers reported in Janu-
ary of 1925 that “thousands” of ducks
were dying in Louisiana, apparently from
lead poisoning, for all the specimens ex-
amined were found to have ingested lead
shot; and that large numbers of ducks
died from lead poisoning in the Jacobs
and Pecan Lake region of Arkansas in
January of 1925.
Van Tyne (1929:103-4) reported
that at Houghton Lake, Michigan, in
April of 1928, greater scaups (Aythya
marila) died from lead poisoning. Of 10
eu
*
er enter
Synch es alin a ilies toe
yy Se
At eee on OT Fa le 9 ge BT
May, 1959
stomachs examined by Van Tyne, most
contained 40 to 60 pellets of lead, and
one contained 80 pellets. Elsewhere in
Michigan, Pirnie (1935:74-5) reported
that the deaths of five Canada _ geese
(Branta canadensis) in Barry County in
the spring of 1933, and a similar loss in
Cass County in April, 1935, apparently
were the result of lead poisoning.
Munroe (1925:160) recorded that one
adult trumpeter swan (QOlor buccinator )
and six cygnets had died from lead poison-
ing in British Columbia during the winter
of 1925.
E. R. Kalmbach (unpublished report,
March 6, 1930, in files of U. S. Fish and
Wildlife Service) observed a lead poison-
ing die-off of ducks in the coastal marsh
area south of Gueydan, Vermilion Par-
ish, Louisiana, in February of 1930. Ina
200-acre rice field he found 199 dead
ducks: namely, 120 pintails, 71 mallards,
and 8 lesser scaups (Aythya affinis).
Kalmbach believed that the toll in the rice
field was greater than that found in any
other area of similar size, but that losses
occurred throughout 300 or more square
miles of marsh. Albert Bonin, a resident
of that area, told Kalmbach that sick
ducks had been observed in the Florence
section for at least 30 years. In Bonin’s
experience, the spring of 1921 marked the
severest outbreak noted in that region.
Shillinger & Cottam (1937:399) re-
corded the following waterfowl losses
from lead poisoning, all in the fall and
early winter of 1936: 8 ducks from the
coast of North Carolina; 5 mallards
from the Pamlico Sound area of Virginia ;
14 ducks from Delaware Bay; 12 ducks
from northern Ohio; and 100 ducks,
most of them mallards, from Boyd Lake,
Colorado. The same authors (1937 :402)
gave an account of a die-off of ducks at
the Sand Lake National Wildlife Refuge,
South Dakota, during November and De-
cember of 1935. Of 113 mallards exam-
ined there by John J. Lynch, 103 were
deemed victims of lead poisoning. Deaths
of 6 other individuals, representing four
species of ducks, were attributed to this
disease.
Recent Die-Offs
In this review of lead poisoning die-
offs, it has been necessary to rely almost
BELLROSE: LEAD POISONING IN WATERFOWL
239
entirely upon unpublished accounts for
information up to 1937. Since that time
only a few reports have been published
(Mohler 1945; Bellrose 1947; Ayars
1947; Yancey 1953) but, fortunately,
outbreaks have been recorded in letters
and reported by biologists of state conser-
vation agencies and the U. S. Fish and
Wildlife Service.
Data on most of the known die-offs of
waterfowl from lead poisoning for the
period beginning with the winter of 1938—
39 and extending through the winter of
1956-57 are summarized in table 1. These
data have been obtained by contacting all
state conservation agencies in the United
States, as well as those in Ontario and
British Columbia, plus the following
branches of the U. S. Fish and Wildlife
Service: Wildlife Refuges, Game Man-
agement, and Wildlife Research. Most
of the information has been obtained
from letters and file reports graciously
made available by waterfowl biologists of
these agencies.
In addition to the information pre-
sented in table 1, many details have been
made available which could not readily
be recorded in tabular form. Therefore, it
seems advisable to give a flyway-by-flyway
roundup of information on the occur-
rence of waterfowl die-offs resulting from
lead poisoning.
Atlantic Flyway.—Lead poisoning
in waterfowl apparently is not an im-
portant mortality factor in the Atlantic
Flyway. The largest reported losses, table
1, amount to about 600 Canada geese and
whistling swans which were picked up
over a 10-year period in North Carolina.
The following comments, from letters
by waterfowl biologists in that flyway,
illustrate the paucity of reports of die-
ols irom, this malady. Wr Ce b.. D:
Clarke (letter, April 4, 1955) of the On-
tario Department of Lands and Forests
reported: “I know of no die-off worthy
of the name from lead poisoning in On-
tario. From time to time we have picked
up individual poisoned waterfowl at vari-
ous places where they are concentrated.”
Of the situation in Maine, Howard E.
Spencer, Jr. (letter, March 28, 1955),
wrote: “I have no knowledge of any die-
offs which could be associated in any way
with lead poisoning.’ From Vermont,
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242 ILLINoIs NATURAL History SURVEY BULLETIN
William R. Miller (letter, May 19,
1955) reported: “I have on a few occa-
sions seen what to my mind was a case of
death due to lead poisoning.” James A.
Lee (letter, March 29, 1955) reported:
“As far as I can ascertain, we have never
had a waterfowl die-off in New Hamp-
shire attributable to lead poisoning.”
Charles L. McLaughlin (letter, May 23,
1955) reported: “I have no authentic rec-
ords of ducks dying of lead poisoning in
Massachusetts, and it is my opinion that
this type of mortality is unimportant in
the state. A few years ago reports of large
scale mortality from lead poisoning in the
coastal wintering black ducks was re-
ported, but investigation revealed that the
mortality was due to starvation rather
than lead.”’ Ruth S. Billard (letter, May
3, 1955) reported as follows for the Con-
necticut State Board of Fisheries and
Game: “We are not aware of any water-
fowl succumbing from lead poisoning.”
Thomas J. Wright (letter, April 26,
1955) reported: “Rhode Island, to the
best of my knowledge, has never had any
waterfowl losses that could be attributed
to lead poisoning.”
From New York, Donald D. Foley
(letter, May 3, 1955) wrote: “There are
without doubt many instances of such poi-
soning in this state, particularly in late
winter and early spring, of which we are
not aware. However, we feel that the
over-all picture is not too serious as to di-
rect mortality.” L. G. McNamara (let-
ter, April 27, 1955) reported: ‘‘As far as
we know, lead poisoning is not a problem
in New Jersey.” Robert E. Stewart (let-
ter, May 21, 1955) of the U. S. Fish and
Wildlife Service, in referring to the
Maryland marshes, reported: “On sev-
eral occasions, during the pdst years, div-
ing ducks which appeared unable to fly
were collected and found to contain worn
lead pellets.’ In Delaware, Everett B.
Chamberlain (letter, April 11, 1955)
knew of only two duck deaths which were
suspected to be from lead poisoning.
In Virginia, C. P. Gilchrist, Jr. (let-
ter, June 20, 1955), expressed his belief
that some ducks are lost to lead poison-
ing, but not in large enough numbers ta
be brought to the attention of the Com-
mission of Game and Inland Fisheries.
Farther south, T. Stuart Critcher (let-
Vol. 27, Art. 3
ter, May 13, 1955), reporting from North
Carolina, remarked: “To my knowledge
we have no records of losses in waterfowl
populations as a result of lead poison. Un-
doubtedly, such losses do occur from
time to time.” Dr. J. H. Jenkins (letter,
May 12, 1955) of the University of
Georgia wrote: “I don’t know of a sin-
gle case of lead poisoning of waterfowl in
Georgia. For one thing, there is very lit-
tle shooting over established marshes.” E.
B. Chamberlain, Jr. (letter, April 22,
1955), reported concerning lead poison-
ing: “So far as we have been able to de-
termine, there have never been any large
scale losses of waterfowl in Florida due
to this cause.”
Mississippi Flyway.—All but three
states in the Mississippi Flyway have re-
ported die-offs of waterfowl as a result of
poisoning from ingested lead shot, table 1.
Among the largest losses have been those
reported from Louisiana. The largest
die-offs in Louisiana have been at Cata-
houla Lake in La Salle Parish, where 20,-
300 ducks are estimated to have died
from lead poisoning in the period 1950-
1955. Lead poisoning among the water-
fowl of Catahoula Lake probably dates
back farther than 1930, for E. R. Kalm-
bach in his 1930 report (on file, U. S.
Fish and Wildlife Service) mentions a
duck malady as occurring in previous
years at that lake.
The largest known single outbreak of
lead poisoning occurred in the Claypool
Reservoir area near Weiner, Arkansas,
between mid-December of 1953 and mid-
February of 1954. John W. Perkins (let-
ter, February 12, 1954), game agent for
the U. S. Fish and Wildlife Service, esti-
mated that during that period 16,000
ducks, most of them mallards, succumbed
to lead poisoning.
A similar die-off of mallards had pre-
viously occurred there in early February
of 1951. The die-off was investigated by
John J. Lynch (letter, February 9, 1951)
of the U. S. Fish and Wildlife Service,
who reported seeing over 50 carcasses on
less than 3 acres of the 1,300 acre reser-
voir. He concluded that the casualties
“numbered in the thousands.” Further-
more, Lynch stated that a die-off of simi-
lar proportions occurred on the same res-
ervoir in the winter of 1948—49.
May, 1959
In Missouri, the largest reported die-
off of ducks from lead poisoning took
place at the Squaw Creek National Wild-
life Refuge, where 10,000 out of 150,000-
205,000 mallards died during the winter
of 1956-57. In the previous winter, 5,000
mallards out of the 200,000 on the ref-
uge died from lead poisoning. Other die-
offs occurred there every winter at least
as far back as 1945; reported mortality
varied from 50 to 300 victims per year.
Additional die-offs of mallards occurred
at Dalton Cut-off in Chariton County in
1949 and at the Swan Lake National
Wildlife Refuge in 1939, 1952, 1953, and
1954.
Hovey Lake, Posey County, Indiana,
has been a trouble spot for many years.
As mentioned earlier, Phillips & Lin-
coln (1930:165) reported ducks dying
there from lead poisoning as far back as
1922. The largest die-off there in recent
years, an estimated 1,000 ducks, took
place during the winter of 1947-48
(James D. McCall, letter, February 5,
1955). Reported losses since then have
been sporadic and rather small, except for
the death of 219 Canada geese in 1953
and 120 in 1955-56 (Martin 1957:114).
Small die-offs, aggregating 678 birds, are
reported to have occurred at Hovey Lake,
the Kankakee State Game Preserve area
(Starke County), and the Willow Slough
State Game Preserve (Newton County)
during January and February, 1955.
Since 1947, wherever large numbers of
mallards have wintered in central Ilinois,
there have been some outbreaks of lead
poisoning. Most of the reported die-offs
have occurred on, or in the vicinity of,
the Chautauqua National Wildlife Ref-
uge, near Havana, where 13,000 ducks
are estimated to have died from lead poi-
soning in the period 1941-1957, table 1.
The largest single outbreak of lead poison-
ing among waterfowl of Illinois occurred
there in January and February of 1957,
when an estimated 5,000 succumbed. The
second largest die-off occurred at Stump
Lake, north of Grafton, where 3,000 mal-
lards were victims of lead poisoning in
January, 1948.
In Iowa, sporadic outbreaks of lead poi-
soning among ducks have been noted since
1936, according to Everett B. Speaker
(letter, February 23, 1955), but only one
BELLROSE: LEAD POISONING IN WATERFOWL 243
die-off amounted to over 1,000 birds, ta-
ble 1. That one took place at Forney
Slough, in Fremont County, during the
winter of 1948.
Reported losses from lead poisoning
among waterfowl in the lake states of
Minnesota, Wisconsin, and Michigan
have been minor, table 1. In Wisconsin,
small losses of whistling swans occurred
in the Green Bay area in the springs of
1948-1954. L. R. Jahn (letter, February
16, 1955) reported that, although ducks
were victims of lead poisoning in both
spring and fall, their losses had been spo-
radic. H. J. Miller (letter, February
23, 1955) wrote that Michigan had not
known an appreciable die-off of ducks
from lead poisoning since the taking of
waterfowl records was begun in 1940. In
the spring of 1942, 16 whistling swans
were found dead from lead poisoning on
widely separated marshes of southeastern
Michigan. In the winter of 1953-54,
100 whistling swans and 75 mallards were
reported as dying from lead poisoning at
the Shiawassee National Wildlife Refuge,
near Saginaw (Richard E. Griffith, letter,
April-1,- 1955).
After studying the mortality in large
populations of ducks wintering, 1949-
1952, on the Detroit River in Michigan,
Hunt & Ewing (1953:362, 367) con-
sidered lead poisoning to be of little im-
portance as a mortality factor.
In Ohio, lead poisoning has evidently
been a minor problem, for Delmar Hand-
ley (letter, April 28, 1955) stated that
only a few ducks and geese had been found
afflicted by this disease. A suspected case
of lead poisoning in Tennessee waterfowl
was reported by Parker Smith (letter,
May 5, 1955) as affecting 40 or 50 mal-
lards along the Obion River in February,
1954.
In three states of the Mississippi Fly-
way, Kentucky, Mississippi, and Alabama,
lead poisoning losses have not been re-
ported (letters: Frank Dibble, April 12,
1955; W. Walter Beshears, Jr., May 9,
1955; and Alec Bumsted, March 1,
1955), but some losses undoubtedly oc-
cur in those states.
Central Flyway.—Although die-offs
of waterfowl from lead poisoning have
occurred at several places in the Central
Flyway, they have not been so large as
244
those in the Mississippi Flyway, table 1.
Largest losses in the Central Flyway have
been reported from the Sand Lake Na-
tional Wildlife Refuge area of South Da-
kota, where more than 10,700 mallards
succumbed to lead poisoning over a span
of 10 winters.
A large die-off of ducks reported in
Lubbock County, Texas, during the win-
ter of 1944 was a most unusual one. De-
tails were reported in a letter (June 18,
1945) from Oscar L. Chapman, then As-
sistant Secretary of the Department of the
Interior, to the Secretary of War, Henry
L. Stimson. Excerpts are as follows:
“During the past winter approximately
800 wild ducks were found dead at two
small lakes on the grounds of the Lub-
bock Army Air Field, Texas. Field
studies conducted by the Fish and Wild-
life Service of this Department revealed
that these losses were due primarily to
lead poisoning resulting from ingestion of
lead shot which drop into one of these
lakes during skeet practices. Studies con-
ducted by Army personnel indicated that
80 per cent of the dead ducks examined
contained lead pellets in their gizzards.
. . . It is estimated that the annual loss
from the two lakes is between 5,000-—10,-
000 ducks, many of which perish on their
northward migration. This estimate is
substantiated by numerous reports of ema-
ciated dead and live ducks being found or
seen in areas north of Lubbock.”
In Nebraska, George V. Schildman
(letter, March 5, 1955) reported siz-
able die-offs of blue geese (Chen caeru-
lescens) and lesser snow geese (Chen hy-
perborea) from lead poisoning, table 1.
In regard to loss of ducks, he stated:
“The numerous rainwater basins in Clay,
Fillmore, and York counties provide some
losses each spring. . . . The losses are com-
monplace, but—to my knowledge—
haven’t been conspicuous and _ concen-
trated. However, these basins cover an
extensive area, and the total loss may be
considerable.”
According to Richard E. Griffith (let-
ter, April 1, 1955): “Minor losses have
been reported from the Salt Plains Ref-
uge (Oklahoma), usually in single iso-
lated cases. An occasional bird with lead
poisoning is picked up on other refuges
throughout the Southwest, but in most in-
I~ttrnors NaturAL History SURVEY BULLETIN
Vol. 27, Art. 3
stances it is felt the shot was ingested
prior to arrival.’’ Griffith reported some
fatalities among mallards at the Fort Peck
Game Range in Montana, where 5,000 to
17,000 winter. Elsewhere in Montana,
Wynn G. Freeman (letter, April 23,
1955) reported he had found no water-
fowl suffering from lead poisoning.
Other waterfowl biologists in the Cen-
tral Flyway who have yet to find mor-
tality in waterfowl from lead poisoning
are B. A. Fashingbauer (letter, February
17, 1955), North Dakota; Robert L.
Patterson (letter, February 8, 1955), Wy-
oming; and Levon Lee (letter, February
19, 1955), New Mexico.
Pacific Flyway.—The largest out-
breaks of lead poisoning among waterfow]
of the Pacific Flyway have been reported
from California, table 1. In 1939, ducks
estimated at 9,500 died from lead _ poi-
soning in the Central Valley, San Fran-
cisco Bay, and Suisun Bay areas of Cali-
fornia, table 1, but it is not known to
what extent die-offs approach this number
every year, for the problem was investi-
gated in detail in only that year by the
California Department of Fish and Game.
In the winters beginning in 1944 and end-
ing in 1954, 4,000 ducks were estimated
to have become victims of lead poisoning
at the Salton Sea National Wildlife Ref-
uge in southern California.
Both the Tule Lake and the Lower
Klamath National Wildlife refuges in
northern California, according to Rich-
ard E. Griffith (letter, ‘May 17, 1955),
have sections heavily shot over, and yet
reported losses from lead poisoning have
been surprisingly low.
From Utah, Noland F. Nelson (letter,
February 19, 1955) reported regarding
lead poisoning: “During the past 10 years
of waterfowl management work on Utah’s
marshlands, I have observed no large die-
offs of waterfowl resulting from lead poi-
soning. However, a few lead poisoning
losses have been recorded every year.
These recorded losses were almost always
during the winter and early spring
months on some of the areas of heavy
shooting around Great Salt Lake... .
A few emaciated mallard, pintail, shov-
eler, and whistling swan have been exam-
ined almost every winter and a large per
cent have contained ingested lead shot.
May, 1959
The keeper of a local aviary rescued 33
sick whistling swans one winter and 28
died from lead poisoning.”
In discussing losses of waterfowl from
lead poisoning at the Bear River Migra-
tory Bird Refuge, Utah, Richard E. Grif-
fith (letter, April 1, 1955) emphasized
that the loss cited, table 1, was a mini-
mum one and should not be construed as
a reliable indicator of total mortality. He
reported that outbreaks of lead poisoning
occurred when ice restricted the birds to
a limited feeding area. The development
of this situation was most apparent among
the 10,000-12,000 whistling swans win-
tering at the refuge, for they began to die
from lead poisoning as soon as the feed-
ing areas became restricted by ice.
Thirteen trumpeter swans affected by
lead poisoning were found by Dr. Ian
McT. Cowan (Tener 1948:12) in Feb-
ruary of 1943 on Vancouver Island, Brit-
ish Columbia. However, only a very few
ducks have been found ill from lead poi-
soning in that province (E. W. Taylor,
letter, March 22, 1954).
In regard to lead poisoning in Wash-
ington, Henry A. Hansen (letter, Febru-
ary 26, 1955) wrote: “It has been a rare
and isolated case that weak or dead ducks
have been found to have lead shot in their
gizzards in this state since we organized
the waterfowl research project in 1947.
In no instance have we found a trouble
spot that might require remedial action.”
Chester E. Kebbe (letter, April 21,
1955) reported that, although an out-
break of lead poisoning had not been no-
ticed in Oregon, he believed that research
would reveal large numbers of waterfowl
dying each year from ingested shot. Rich-
ard E. Griffith (letter, May 17, 1955)
reported that records at the Malheur Na-
tional Wildlife Refuge in southwestern
Oregon indicated that there had been no
losses from this malady in the previous 7
years. A few waterfowl, mostly diving
ducks, were victims of lead poisoning at
that refuge in 1942.
C. Vic Oglesby (letter, March 31,
1955) reported: ‘There have been no
major die-offs nor any approaching even
moderate die-offs in Nevada within the
past 10 years. A very few birds, primarily
shovelers, fall victim to lead poisoning
each fall on the Stillwater Wildlife Man-
BELLROSE: LEAD POISONING IN WATERFOWL
245
agement Area located near Fallon, Ne-
vada. This is our largest public hunting
area and bears the bulk of the waterfowl
shooters within the state.”
In Arizona, no losses of waterfowl
from lead poisoning have been reported
during the past 10 years, according to
Wesley B. Fleming (letter, February 8,
1955).
Undoubtedly not all the outbreaks of
lead poisoning among waterfowl during
the past decade have been reported. How-
ever, it is believed that outbreaks dis-
cussed in this paper include the most im-
portant die-offs from lead poisoning, and
that these outbreaks represent a cross sec-
tion of such conditions in the United
States. Today there are only a few places
in this country where 1,000 or more ducks
might succumb from lead poisoning and
not be noticed. Past experience shows
that the public becomes alarmed when
large numbers of dead ducks are observed
and that it reports such events to conser-
vation authorities or the press.
Moreover, waterfowl are prone to con-
centrate in and around refuges; refuge
personnel would be among the first to be-
come aware of and report any unusual
waterfowl mortality. Since the early
1930’s, there have been numerous federal
refuges, manned with technically trained
personnel, well distributed throughout the
four flyways.
In addition to the waterfowl die-offs
that attract public attention, there are
the scattered day-to-day losses that pass
unnoticed. These day-to-day losses are ex-
tensive; their magnitude is explored later
in this paper on the basis of the incidence
of ingested shot in waterfowl populations
and the toxicity of various doses of lead
shot.
Lead poisoning outbreaks have occurred
more commonly in the Mississippi Flyway
than in all the other flyways combined.
In both the Mississippi and Central fly-
ways, mallards have been the principal
victims in all but a few die-offs. A rough
estimation of the annual rate of loss of
mallards in outbreaks of lead poisoning in
the Mississippi Flyway is 1 per cent.
Frequency of Die-Offs
Some areas have outbreaks of lead poi-
soning in waterfowl rarely, some occa-
246
sionally, and others with rather consistent
frequency. For example, in Illinois there
has been but one outbreak of lead poison-
ing near Henry in 18 years; near Grafton
there have been two outbreaks in 12 years;
at the Chautauqua National Wildlife
Refuge there have been outbreaks in 10
of the last 13 years.
The frequency and magnitude of lead
poisoning outbreaks in a particular area are
influenced largely by the following fac-
tors: the size of late fall and winter popu-
lations of mallards and other species of
ducks with similar feeding habits; the
kind and amount of food available; the
amount of lead shot present as a result of
shooting pressure; the availability of shot,
determined by bottom conditions, water
levels, and ice cover.
One reason that the Chautauqua Na-
tional Wildlife Refuge area has been the
scene of many outbreaks of lead poisoning
in waterfowl is that generally 100,000 to
400,000 mallards winter there, making it
usually the area of largest winter concen-
tration in Illinois. Another reason is that
nearby Quiver Creek, which remains
partly open during the coldest weather, at-
tracts a large proportion of the wintering
population to its shot-laden stream bed.
Water levels, food, and a lack of ice
cover combined to cause the exceptionally
large die-off of 5,000 mallards in the
Chautauqua area during the winter of
1956-57. A rise in water resulted in the
flooding of millet and smartweed beds
adjacent to the refuge shortly after the
hunting season closed. This area had been
heavily shot over, and mallards congre-
gated there for a week before a freeze-up
forced them to leave. Most of them moved
to Quiver Creek. Two to 3 weeks later,
mallards in the Quiver Creek area com-
menced dying by the hundreds.
Other areas in the Mississippi Flyway
where there have been consistently fre-
quent outbreaks of lead poisoning include
Catahoula Lake, Louisiana, 4 out of 6
years; Claypool Reservoir, Arkansas, 3
out of 8 years; and Squaw Creek Na-
tional Wildlife Refuge, Missouri, 8 out
of 13 years.
Seasons of Die-Offs
As shown by data in table 1, most wa-
terfowl die-offs from lead poisoning have
ILtinois NATURAL History SurvEY BULLETIN
Vol. 27, Art. 3
occurred during the late fall and early
winter months, after the close of the
hunting season. Only a very few die-offs
have been noted during the hunting sea-
son, even though in the southern zone
the season has usually extended to Janu-
ary 10 or 15. Two large outbreaks have
been reported during the hunting season:
One of these occurred at Catahoula Lake,
Louisiana, during the last two weeks of
November and the first week of Decem-
ber in 1950; the other took place in the
Claypool Reservoir area of Arkansas be-
tween mid-December of 1953 and early
February of 1954.
Outbreaks of lead poisoning are un-
usual during the early fall months.
Hunter activity keeps ducks out of heavily
gunned areas where shot pellets are most
heavily deposited, and, as shown later, a
sizable number of the ducks suffering
from the effects of lead poisoning are shot
by hunters.
Outbreaks of lead poisoning seldom
have been noted among waterfowl during
the spring. Principal losses at this season
have been among swans and geese. Whis-
tling swans have been recorded as dying
during the spring at Green Bay, Wiscon-
sin, and on the Shiawassee National Wild-
life Refuge, Michigan, table 1. A die-off
of Canada geese took place in April, 1954,
at Lake Puckaway, Wisconsin. In Nebras-
ka, losses of blue geese and snow geese
have occurred for a number of years dur-
ing March and April. Greater scaups
were reported by Van Tyne (1929:103-
4) as dying at Houghton Lake, Michigan,
during April, 1928. In the spring of
1921 near Florence, Louisiana, many
ducks died from lead poisoning, according
to Albert Bonin, quoted in an unpub-
lished report by E. R. Kalmbach.
There are no records to indicate that in
recent years wild waterfowl have died
from lead poisoning during the summer
months. However, Wetmore (1919:2)
stated that during the summers of 1915
and 1916 he handled many ducks af-
fected by lead poisoning in the Bear River
Delta of Great Salt Lake, Utah. In spite
of numerous and intensive investigations
on botulism and other waterfowl problems
at the Bear River Migratory Bird Refuge,
lead poisoning losses have not been re-
corded there during the summer since
May, 1959
Wetmore (1919) reported on his field
work of 1915 and 1916.
Species Affected by Die-Offs
Individuals of most species of water-
fowl have been recorded at one time or
another as victims of lead poisoning. In
addition to those species listed in table 1,
the following species have been reported
as victims: trumpeter swan, white-fronted
goose (Anser albifrons), gadwall (Anas
strepera), baldpate (Mareca americana),
blue-winged teal (Anas discors), cinna-
mon teal (Anas cyanoptera), shoveler
(Spatula clypeata), canvasback, greater
scaup, common goldeneye (Bucephala
clangula), and ruddy duck (Oxyura ja-
maicensis). ‘The largest number of spe-
cies reported from any one area was found
by Donald D. McLean (unpublished re-
port, California Department of Fish and
Game) in the San Francisco and Suisun
Bay areas of California. He reported 257
pintails, 45 shovelers, 15 baldpates, 13
green-winged teals (dnas carolinensis),
7 mallards, 2 lesser Canada geese, 1 cin-
namon teal, and 1| canvasback in a group
of waterfowl which had succumbed from
lead poisoning.
Although individuals of many species
have died from lead poisoning, it is evi-
dent that the mallard has been the prin-
cipal victim in outbreaks of lead poison-
ing across the nation, table 1. In the Pa-
cific Flyway the pintail has made up the
largest number of victims. In the Missis-
sippi Flyway, however, where mallards
and pintails have frequented the same
areas, mallard losses have been propor-
tionately greater, table 1. Die-offs of
the Canada goose, blue goose, and snow
goose have been reported for several
places, table 1, but losses in these die-offs
have been comparatively small.
An investigation of a lead poisoning
outbreak at Catahoula Lake, Louisiana,
in January of 1953 pointed up important
differences in the mortality rates of spe-
cies. During the period of the outbreak,
the waterfowl population was composed
of 30,000 pintails, 25,000 mallards, 5,000
green-winged teals, and small numbers
of a few other species. Although pintails
outnumbered mallards in the population,
5,500 mallards and 1,000 pintails were
estimated to have died from lead poison-
BELLROSE: LEAD POISONING IN WATERFOWL
247
ing. In a 3-day period, 243 mallards and
only 26 pintails were picked up. Not a
single dead or incapacitated green-winged
teal was found.
From these observations, it was de-
duced that the habits of the several species
of ducks were such as to account for the
different mortality rates. Observations of
the feeding ducks plus unpublished food
habits studies of ducks at Catahoula Lake
by Richard K. Yancey of the Louisiana
Wild Life and Fisheries Commission sug-
gested that both feeding traits and food
preferences were involved. Ducks of all
three species, mallard, pintail, and green-
winged teal, were feeding extensively in
flooded beds of chufa (Cyperus esculen-
tus), but mallards were puddling more
commonly into the bottom for tubers of
this plant than were pintails, which were
probably feeding more commonly on the
Hoating seeds. Green-winged teals ap-
peared to be feeding almost entirely on
floating seeds.
Apparently, in puddling into the bot-
tom mud, mallards came into contact with
the lead shot more frequently than did
pintails, and pintails more frequently than
did green-winged teals. The form of the
food they consumed undoubtedly influ-
enced mortality among those ducks ingest-
ing shot. Jordan & Bellrose (1951:18)
reported that ducks that fed on small
seeds were less affected by ingested lead
than were those that fed on corn. The
tubers of chufa and the kernels of corn
appear to have similar physical proper-
ties and they may be expected to have
similar effects.
Incidence of Lead Shot in Die-Offs
Biologists investigating outbreaks of
lead poisoning among waterfowl in the
Mississippi Flyway, 1938-1955, exam-
ined samples of dead and dying mallards
for ingested shot, tables 2 and 3. AlI-
though 10.4 per cent of the drakes, table
2, and 13.0 per cent of the hens, table 3,
found in the outbreaks carried no shot in
their gizzards, most, if not all, of these
were lead-poisoned victims. James S.
Jordan (unpublished report) found in
controlled experiments with captive mal-
lards that 21 per cent of those dosed with
one to four No. 6 shot pellets had no pel-
lets in their gizzards at time of dearh.
248 Ittrnois NaTurRAL History SurveEY BULLETIN
Vol. 27, Art. 3
Table 2.—Incidence of various ingested shot levels found among drake mallards picked up
level is meant the number of ingested lead shot pellets found in a gizzard.) For each state are
O PELLET 1 PELLET 2 PELLETS 3 PELLETS 4 PELLETS § PELLETS
Location |
Num-| Per |Num-| Per |Num-} Per |Num-} Per |Num-| Per | Num-!} Per
ber | Cent | ber | Cent | ber | Cent | ber | Cent | ber | Cent | ber | Cent
South Dakota 4 11.8 17, 50.0 8 28 pals 5 14.7 0 0.0 0 0.0
Minnesota...| 17 13.8 36 29.3 yy) 17.9 15 12.2 10 8.1 4 3.3
Missouri.... . 6 14.0 8 18.6 5 11.6 6 14.0 9 20.9 5 11.6
Illinois... .. 37 11.9} 90 | 29.0] 49 Ld8 36 11.6 18 5.8 23 7.4
Arkansas.... 3 4.1 6 8.2 20 27.4 8 11.0 5 6.9 3 4.1
Louisiana... 5 4.6 3 28 15 13.9 16 14.8 20 8.5 15 13.9
Tatali 423-72 Loe ie oY) Pa eel bol AY se 80 60 ae 50
Average. . 10.4 Poy Ow) Tre lia by eo LDA er. 9.0 Wad
Table 3.—Incidence of various ingested shot levels found among hen mallards picked up
level is meant the number of ingested lead shot pellets found in a gizzard.) For each state
OQ PELLET 1 PELLET 2 PELLETS 3 PELLETS 4 PELLeTs 5 PELLETS
LocaTION
Num-} Per |Num-| Per |Num-} Per |Num-| Per |Num-| Per |Num-| Per
ber | Cent | ber | Cent | ber | Cent | ber | Cent | ber | Cent | ber | Cent
South Dakota} 0 | 0:0} -12 | 48.0] -7 | 28.0] 3 | 12.0} 3 | 12.07 "O00 jiegng
Minnesota. . 11 15.5 30 42.3 13 18.3 7 9.9 3 4.2 3 4.2
Missouri... . 3 11.1 7 25.9 3 11.1 6 Pyles) 5 18.5 1 37
Illinois... .. 32 18.1 57 S2e2 30 17.0 19 10.7 7 40 5 2.8
Arkansas... 6 2252. 7 25.9 2 7.4 3 late 2 7.4 1 Bia
Louisiana... 8 5.9 11 8.1 21 15.6 31 23.0 16 11.9 18 13.3
Total.....| 60 Eatin Ot reer 70 seed eeOD, aah 36 ooh 2a
Average. . 4166 oak fern eate| [ n° UN Ys Reapege sre (ty ICs en lopment [2 EL a pene TS ee eee 6.1
It is apparent that most, if not all,
waterfowl found dead without ingested
shot in a lead poisoning outbreak had pre-
viously ingested lead, but that the lead
had passed from their digestive tracts at
such late stages of illness that the birds
failed to recover. The low proportion of
free-flying, lead-poisoned mallards found
without ingested shot, as compared with
the proportion of lead-poisoned penned
birds without ingested shot, suggests that
birds in the wild that succeed in voiding
shot are more likely to survive than are
penned birds.
Considerable variation was evident in
the amounts of ingested lead shot in mal-
lard drakes found dead or dying in four
areas. The lowest number of shot pellets
per duck was among those affected by lead
poisoning at the Sand Lake National
Wildlife Refuge, South Dakota, in De-
cember of 1951, fig. 3. The next smallest
number of ingested shot pellets per duck
was among birds picked up, 1941-1954, in
the vicinity of the Chautauqua National
Wildlife Refuge, Illinois. “The mallards
of the Claypool Reservoir, Arkansas, and
the Catahoula Lake, Louisiana, out-
breaks had a larger number of ingested
shot pellets per duck than did those of the
Illinois outbreaks, fig. 3.
Differences between the four areas in
numbers of pellets per drake are believed
to have resulted mainly from the differ-
ences in (1) availability of shot and (2)
diet. The quantity of shot ingested by
ducks of a given species is roughly pro-
portional to the availability of shot. Diet
has an important influence on the sur-
vival of ducks that have ingested lead, ac-
cording to Jordan & Bellrose (1951 :18-
21), who reported that the harmful effect
of ingested lead was most evident in
ducks fed on whole corn and much less
raat ee 6H"
May, 1959
BELLROSE: LEAD POISONING IN WATERFOWL
249
in a dead or moribund condition in lead poisoning die-offs in six states, 1938-1955. (By shot
given the number and per cent of drakes represented at each shot level.
Over 10
6 PELLETS 7 PELLETS 8 PELLETS 9 PELLETS 10 PELLETS Tora.
PELLETS
Num-| Per | Num-| Per |Num-| Per | Num-| Per | Num-| Per |Num-}] Per |Num-| Per
ber | Cent | ber | Cent | ber | Cent] ber | Cent | ber | Cent | ber | Cent | ber | Cent
0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 gee “100.0
8 6.5 2 1.6 l 0.8 0 0.0 3 2.4 5 4.1} 123 100.0
I 223 1 23 | QF | D3 0 0.0 0 0.0 | 43 99.9
9 29 5 1.6 7 De3 4 8} 6 1.9 26 8.4 | 310 99.9
6 8.2 2 PEA 4 5 6 8.2 2 27 8 11.0 73 100.0
10 9.3 6 5.6 5 4.6 2 18 4 Say, il 6.5 | 108 100.0
34 16 aks 18 ies Eas A. 15 ek 46 See 691 Goo
phone 4.9 28 DG Ie 9 fevanes Did ales exces Gaia | LOORO
in a dead or moribund condition in lead poisoning die-offs in six states, 1938-1955. (By shot
are given the number and per cent of hens represented at each shot level.
6 PELLETS 7 PELLETS 8 PELLETS 9 PELLETS 10 PELLETS Pb 10 Tora.
ELLETS
Num-| Per |Num-|} Per |Num-| Per | Num-| Per |Num-} Per |Num-} Per |Num-]} Per
ber | Cent] ber | Cent | ber | Cent] ber | Cent | ber | Cent | ber | Cent | ber | Cent
9) 0.0 0) 0.0 0 0.0 0 0.0 0 0.0 0 0.0 25 100.0
2 228 0 0.0 | 1.4 1 1.4 0 0.0 0 0.0 71 100.0
0 0.0 0 0.0 9) 7.4 0 0.0 0 0.0 0 0.0 Di 99.9
5 2.8 1 0.6 2 all 1 0.0 1 0.6 17 ONG mii 99.5
2 7.4 2 7.4 0 0.0 0 0.0 1 Si 1 Srv 2 99.9
10 7.4 8 5.9 D AS 5 Bey 1 0.7 4 320) 035 100.0
19 ee, § 11 1 We 7 ie fe oe 3 soe 22 yoke AO?) Nan
ee Ae idl tate DIAN edema fens LS 0.6 4.8 100.0
evident in ducks fed on leafy vegetation
and the seeds of tame rice, millet, and
smartweed.
The high percentage of birds with a
small number of pellets per bird among
the victims in South Dakota probably was
a result of (1) lack of easy availability of
shot and (2) accelerated losses induced
by cold weather and the high toxicity of
lead when associated with the corn diet to
which the birds were restricted during the
winter. Mallards wintering in Illinois,
too, were largely restricted to a corn diet,
but they had available to them much more
shot.
The large numbers of shot pellets per
bird found in mallard drakes in Arkansas
and Louisiana die-offs indicate the avail-
ability of large quantities of shot. The
small number of drakes without ingested
shot, table 2, suggests an excellent sur-
vival of those that had voided shot. Appar-
ently, the mallard drakes of Arkansas and
Louisiana had a better survival rate than
those of South Dakota and Illinois be-
cause they had a better diet and milder
weather.
AVAILABILITY OF LEAD
The availability of lead shot to water-
fowl utilizing a particular body of water
is determined by the following factors:
(1) the shooting intensity, or amount of
shot deposited on the bottom, (2) the
firmness of the bottom material, (3) the
size of the shot pellets deposited, (4) the
depth of water above the bottom, and (5)
ice cover.
The amount of lead deposited on lake
and marsh bottoms as shot pellets from
the guns of waterfowl hunters is tremen-
dous. A conservative estimate of the
number of shells fired for every duck
250
bagged is five; if every shell were of 12
gauge and contained No. 6 shot, then
about 1,400 shot pellets would be depos-
ited for every duck bagged.
In Illinois, the annual kill at some pub-
lic shooting grounds has been as high as
six ducks per acre, but for all Illinois
duck hunting areas over a period of years
the kill has averaged about one and one-
half ducks per acre per year. The amount
of lead shot deposited in Illinois River
valley lakes is calculated to be approxi-
mately 2,100 pellets per acre per year.
+= SAND
eas LAKE
ILtinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 3
Because of the scattered distribution of
blinds, many acres of waterfowl habitat
are untouched by spent shot, while small
areas near blinds have an annual deposi-
tion of shot many times as great as the
calculated average for the larger acreage
of which they are a part. Most blinds are
located on or adjacent to the best water-
fowl feeding grounds. In such situations,
waterfowl are more likely to pick up shot
in their feeding activities than if the
blinds, and therefore the pellets, were
more evenly distributed.
LAKE, SOUTH DAKOTA
CHAUTAUQUA, ILLINOIS
CLAYPOOL RESERVOIR, ARKANSAS
CATAHOULA, LOUISIANA
Sea (LAKE
PER CENT OF MALES
O | rad 3%. 4
oil ne et =) 9... 10 ee
NUMBER OF SHOT PELLETS
Fig. 3.—Incidence of various levels of ingested lead shot found in gizzards of drake
mallards picked up in a dead or moribund condition in each of four areas in which lead
poisoning die-offs occurred, 1941-1954. Data, except those for Illinois, are from table 2.
May, 1959
A number of surveys have been made
of lake and marsh bottoms in an effort to
ascertain the availability of lead shot to
waterfowl. Wetmore (1919:9-10), i
his pioneering investigation of lead poi-
soning, examined mud from two areas at
the mouth of the Bear River in Utah. In
one area he found no shot pellets within
30 to 70 yards of a blind, but he found
pellets at sampled 20-yard intervals from
70 yards to as far as 210 yards from the
shooting point. He found most pellets at
a distance of 130 yards, where he recov-
BELLROSE: LEAD POISONING IN WATERFOWL 251
13 pellets at each sampling point; most
of the pellets had penetrated through 10
to 12 inches of a soft upper layer of mud
to a lower layer of hardened clay.
More recent studies, table 4, show the
concentrations of lead pellets in bottom
samples, most of them taken without spe-
cific orientation to shooting blinds. The
bottom material sampled varied in thick-
ness from 2 to 10 inches.
The greatest concentration of lead shot
that has been reported was at Lake Puck-
away, Wisconsin, table 4. Hartmeister &
ered 1 to 12 in each sieve filled with mud.
In the other area, Wetmore found | to
Hansen (1949:18-22), after investigat-
ing three Wisconsin shooting areas, re-
Table 4—Number of lead shot pellets per square foot and per acre found in samples
of the bottom soils of various lakes and marshes used extensively by waterfowl in North
America. The bottom samples varied from approximately one-half inch to 10 inches in
thickness.*
|
YEAR NumBer OF | NumBer oF | NuMBER
STATE AREA AND SovareE Feet|/PELLetTs Per} or PELLETS
SEASON IN SAMPLE |SouaRreE Foot] Per Acre
California...| Sacramento Valley.. jer) 98S 1820) 60 0.45 19,602
North Bay, San Francisco. . Springs 120 0.78 333977
SWisW BAY ses. ee: Sr 260 0.58 25,265
Welearceo: so 80 0.20 8,712
South Bay, San Francisco. . . 240 0.79 34,412
San Joaquin valor s oa 120 bea 59,677
South Coast. Sy eal. 2 40 0.48 20,908
Minnesota...}| Lakes on Carlos Avery 1939-1940
Refuge. . bie Winter 80 0.41 17,859
Lakes adjacent to Carlos
Avery Refuge..........+.. 94 Ons ese
Ree ie a). 53 0.55 23,958
Rush@lhak ease ny aue cee cree e 11 0.00 0
Fleronwluakerner cert weetss soe 36 1.47 64,032
ie) RE a 2, a rae ee 249 0.14 6,098
Wisconsin...) Lake Puckaway....-./...... 1949 100 pri 118,048
Glanmitakete sn we ayas. dase Winter 67 1.06 46,174
Horicon Marsh a0. eared 53 0.08 3,485
Manitoba. ..| Portage Creek, Delta Marsh 1950 186 Lead 50,965
Cadham Point, Delta Marsh Summer 195 0.39 16,988
Michigan: ...| Saginaw Bay........2225... e 45 m2, 11,761
Maumee. Bayinn... 2 Maek-. 200 OF 27 11,761
imran)... | Willow Slough. .).': So... 1956 14 0.93 40,511
Spring, Fall 14 1.07 46,609
Illinois... ...} Quiver Lake..... 1950 22 0.00 0
Moscow Bay... Summer 60 0.04 1,742
*Sources of data: California: “‘Lead poisoning of California waterfowl,’ unpublished report by Donald D. McLean,
Bureau of Game Conservation, California Division of Fish and Game; Minnesota: unpublished reports by Gustav
Swanson and C. Gordon Fredine, in Cooperative Wildlife Investigations, University of Minnesota and Minnesota Divi-
sion of Game and Fish, Vol. 1, 1937-1939; Vol. 2, 1939-1940; Wisconsin: Hartmeister & Hansen 1949; Manitoba:
“Occurrence of lead shot in a waterfowl breeding marsh, ” by George K. Brakhage, unpublished quarterly report of
the Missouri Wildlife Research Unit, July—September, 1950; Michigan: “Waterfowl survey of Saginaw Bay, Lake
St. Clair, Detroit River, Lake Erie and the marshes adjacent to these waters,’ by Herbert J. Miller, unpublished final
report, P-R Project 13-R, Michigan Department of Conservation, January 1, 1943; Indiana: Martin 1957.
252 Intrnoris NaturAL History SurRVEY BULLETIN
ported 2.71 pellets per square foot (equiv-
alent to 118,048 pellets per acre) at Lake
Puckaway, less than half as many pellets
per square foot at Clam Lake, and a “neg-
ligible amount of lead shot available to
waterfowl” on Horicon Marsh. Lake
Puckaway, they reported, has a bottom of
sand and gravel covered by a thin layer
of vegetable matter 1 to 6 inches in depth.
Clam Lake has a similar bottom. The dif-
ference between the areas in number of
pellets per square foot may reflect differ-
ences in hunting pressure.
Hartmeister & Hansen (1949:19) con-
cluded: “Sampling on Horicon marsh re-
vealed a practically negligible amount of
lead shot available to waterfowl, in spite
of the fact that this area is probably as
heavily hunted as any lake or marsh in
the state of Wisconsin. Obviously, lead
shot are soon made unavailable to water-
fowl where deep layers of muck and peat
are present.”
Bottom samples were taken at the Car-
los Avery Refuge in Minnesota 5 years
after it had been closed to shooting; yet
shot pellets were about as numerous there
as in adjacent lakes that were hunted dur-
ing the 5-year period (unpublished Min-
nesota report cited in table 4 footnote).
At Rush Lake, a mud-bottomed water
area, no lead shot was found in samples
taken 15 years after it had been closed to
hunting. The highest concentration of
lead shot found in the Minnesota lakes
sampled was at Heron Lake, which has
a hard clay bottom and had been heavily
shot over, table 4.
Bottom samples taken at Willow
Slough in Indiana by Dale N. Martin
(1957:113) revealed about the same con-
centration of lead shot pellets on October
17, 1956, as on April 26, 1956, table 4.
Apparently, during the 6-month period
the shot had not settled deeper into the
bottom. The bottom area sampled was
composed of one-half to 1.5 inches of silt
and plant debris over firm sand.
In California waterfowl areas, Donald
D. McLean (unpublished report cited in
table 4 footnote) took bottom samples at
levels of 0-2 inches, 4—6 inches, and 8-10
inches below the surface of the bottom.
At these three levels he found 61 per cent
of the shot in the top layer, 30 per cent
in the middle layer, and 9 per cent in the
Vol. 27, Art. 3
lowest layer. There was a noticeable dif-
ference between places; areas with hard
bottoms had most of the shot pellets at
depths of less than 6 inches while areas
with soft bottoms had a greater propor-
tion of shot deeper in the soil. McLean
reported that at the Bolsa Chica Club, in
southern California, there was a heavy
concentration of shot lying on hardpan
under 5.5 inches of soft mud.
Both Portage Creek and Cadham Point
in the Delta Marsh of Manitoba are tra-
ditional shooting sites. Portage Creek re-
ceives much heavier shooting pressure
than does Cadham Point, and shot pellets
were more numerous there, table 4. In
view of the soft mud bottoms of both
areas, the amount of shot found was sur-
prisingly high. George K. Brakhage
stated in an unpublished report cited in a
table 4 footnote that the highest concen-
trations of shot in the Cadham Point area
were along those transects nearest the de-
coy placement. In Michigan, Herbert J.
Miller stated in an unpublished report
cited in a table 4 footnote that at Mau-
mee Bay shot pellets were twice as nu-
merous in areas protected from severe
wave action as in the exposed areas. Part
of this difference may have resulted from
differences in shooting pressure, but Miller
believed that the wave action and cur-
rents were largely responsible in that they
covered much of the lead with sediment.
Bottom samples taken during the sum-
mer of 1950 from two heavily shot-over
lakes in the Illinois River valley showed
few lead shot pellets, table 4; samples
were taken from the top 2 inches of the
bottoms of these lakes. Undoubtedly only
a small amount of lead shot was found
because the expended shot sank in the
soft mud and during spring floods was
covered by a layer of silt. A study on the
silting of Lake Chautauqua (Stall & Mel-
sted 1951:10), an Illinois River valley
lake, showed an average annual silt accu-
mulation of 110 acre-feet in a basin of
3,562 acres.
In water areas with silt or peat bot-
toms, there is, apparently, only a slight
carry-over of lead shot (within the soil
depths at which most ducks search for
food) from one season to the next. Lead
shot is, therefore, most readily available
to waterfowl in the fall and winter, dur-
eS Se a
May, 1959
ing and immediately following the hunt-
ing season. High water levels during the
spring over much of the fall waterfowl
habitat, which includes most shooting
grounds, greatly diminish the availabil-
ity of lead shot. Most breeding grounds
are lightly hunted; therefore, waterfowl
are only slightly exposed to lead shot dur-
ing the breeding season.
As part of a study on lead shot in mud-
bottomed lakes, an experiment was con-
ducted by the writer at Quiver Lake, in
BELLROSE: LEAD POISONING IN WATERFOWL
253
The data in table 5 show that the
smaller the shot size, the smaller the
amount of recovered lead. Evidently wave
action dislodged quantities of shot pel-
lets, especially 71/%’s, and scattered them
outside the pipes. From the distribution
of the remaining pellets, there was, with
the exception of 714’s on the moderately
firm bottom, evidence that the larger the
size, the more prone the pellets were to
sink in the bottom soil. In the soft bot-
tom soil, most of the shot had settled to
Table 5.—Data indicating the penetration of lead shot pellets into bottom soil of two
different types at Quiver Lake, near Havana, Illinois. Figures show for each of five pipes, 8
inches in diameter, placed with upper mouth flush with lake bottom, the number of grams of
shot pellets recovered at various soil depths, September 3, 1953, and the percentage of the
recovered shot that was recovered at each depth. At the upper mouth of each pipe, 150 grams
of shot pellets, No. 744 or No. 6, had been deposited on August 13, 1952.
Sorr Borrom
MoperaTELY Firm Bottom
No. 714 Shot No. 6 Shot No. 71% Shot No. 6 Shot No. 4 Shot
DEPTH OF ao) se] ae] ae] a] a] se] se] a] oy
Sor ee eel ee oe ee eee | tales
nv v Y a or) ‘ D
5106 | 2s | Os: 8e | Og.) es | OR} Es Loe
Eo 50 Eo 5 oO Eo 50 Eo 50 Eo 50
Om Ay mS Om awa 4 Om Oy eS Ox [aWf24 Om w= 4
O-tinen,..-...-|' 26.0 | 35.6) 20.0 ohare bart Soe sls 7(UaTi TOES eT LeO 56.5
1-2 inches. ..... 40.8 So) oH el0) || 7@ell NB}. 265 oer 19.7 | 46.0 36.6
2=S'inches...... 4.0 505 4.5 4.2 8.4 14.8 U9) 2.4 5.8 4.6
3-“4inches...... Los 2.0 0.9 0.9 re 2.6 1.0 Ie Dal Ve,
4-5 inches...... 0.7 1.0 ORO eens es: 0.5 0.9 OFO) ees eee 0.7 0.6
Potal.....-..| 73.0. | 100.0 | 106.4| 100.0:| 56.9 | 100.0 | 92.0 | 100.0 | 125.6 | 100.0
the Illinois River valley, near Havana.
Two areas of the lake bed were selected:
one soft, the other moderately firm. In
each area, three ceramic pipes, each 8
inches in diameter, were sunk into the soil
of the lake bottom during August of 1952,
a period in which the water was only a
few inches deep; the upper mouth of each
pipe was flush with the top layer of soil
of the lake bottom. On the soil in the
upper mouth of each pipe, 150 grams of
shot pellets were deposited: in each of the
two areas were one pipe with No. 4 shot,
one with No. 6 shot, and one with No.
7\% shot.
Slightly over a year later, September 3,
1953, five l-inch layers of soil were re-
moved from each of five pipes and screened
for lead shot. The sixth pipe, the one in
soft mud that contained 4’s, had been dis-
lodged and could not be used further in
the experiment.
the 1—2-inch layer, but, in the moderately
firm bottom soil, the bulk of the shot was
in the top 1-inch layer. However, in both
bottom types, some shot had settled to the
4—5-inch layer.
Ground and aerial observations of dab-
bling ducks feeding in Illinois marshes in-
dicate that most of these ducks feed on or
in the top inch of the bottom material.
Shovelers and green-winged teals have
been watched for many hours wading
through shallow water and skimming the
surface of the bottom. From the air, their
“mud trails” in otherwise clear water give
further evidence of their characteristic
feeding activities. Blue-winged teals may
feed in a manner similar to that common-
ly observed for green-wings, but they
appear to do more tipping-up to puddle
deeper into the bottom mud.
Pintails do considerable skimming of
the bottom in water only a few inches
254
deep, but, in deeper water, they are prone
to puddle out pockets several inches in
depth. Mallards, in Illinois at least, dig
deeper pockets than do pintails, but these
are seldom more than 6 inches in depth.
According to Wetmore (1919:3), mal-
lards and pintails dig away mud to a depth
of 6 to 18 inches and over an area | to 15
feet in diameter as they search for food.
Such extensive digging on the part of
ducks has been observed by the present
writer only around trap sites where large
numbers of birds have sifted through bot-
tom soil day after day for bait. Under
such circumstances, mallards have created
holes as large as 2 feet in depth, 25 feet
in length, and 10 feet in width.
Field observations and food habits stud-
ies indicate that, where underwater leafy
aquatics occur, baldpates and gadwalls
feed almost entirely upon these plants,
seldom, if ever, sifting through bottom
soils for food.
Not only does the depth at which lead
shot occurs in bottom soils determine its
availability to different species of ducks;
the depth of water above the bottom is
also a factor. Species of ducks differ to
some extent in preferred feeding depths.
Dabbling ducks usually utilize waters less
than 15 inches in depth, and diving ducks
feed at depths of many feet. Among the
diving ducks, redheads (Aythya ameri-
cana) and ring-necked ducks (Aythya
collaris) are prone to feed in shallower
water than are lesser scaups and golden-
eyes.
W hen, in late fall or winter, ice fails to
cover waterfowl feeding grounds that
have been heavily shot over, the stage may
be set for a large die-off of ducks. Ice
almost invariably forms first on the shoal
water of ponds, marshes, and lake mar-
gins such as are commonly used by ducks
for feeding and hunters for shooting. The
sealing of these waters by ice makes the
large quantities nf shot on such areas un-
available to waterfowl. At the same time
it may cause the ducks to congregate in
spring holes and spring-fed streams not
covered by ice. If such areas have been
heavily hunted, they are potential sources
of large die-offs caused by lead poisoning.
The extent to which the various spe-
cies of waterfowl are exposed to shot pel-
lets on the bottoms of marshes and lakes
ILtinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 3
is influenced by the feeding habits of the
birds and by the kinds of foods available,
as well as by the numbers of shot pellets
available.
INGESTED LEAD SHOT IN
MIGRATING DUCKS
The incidence of ingested lead shot in
migrating waterfowl populations (the
percentages of ducks that carried ingested
lead at the time gizzards were collected)
was determined by (1) fluoroscopic ex-
amination of live-trapped ducks, (2) com-
pilation of data obtained from other in-
vestigators who had examined waterfow]
gizzards for food content, and (3) fluoro-
scopic and direct examination (Bellrose
1951:126-7) of gizzards numbering many
thousands that co-operating biologists had
collected, especially for this study, from
ducks in hunters’ bags. Most of the data
were from ducks migrating southward in
fall and early winter.
Shot in Live-Trapped Ducks
During the fall months of 1948, 1949,
1950, and 1953, 5,148 mallards were live-
trapped and fluoroscoped at the Chautau-
qua National Wildlife Refuge, near Ha-
vana, Illinois, fig. 4. Ingested lead shot
was found in the gizzards of 10.14 per
cent of these birds, but more than two-
thirds of the gizzards with shot contained
only one pellet each, table 6. Because the
refuge has been closed to hunting since
1944, it is doubtful if much, or any, of the
lead was picked up at the trapping site.
Almost twice as many juvenile as adult
male mallards carried ingested shot, table
6. The data indicate that more hens than
drakes carried ingested shot, but the sam-
ple on which the data are based is believed
biased by an unduly large proportion of
hens fluoroscoped late in the season, when
the incidence of birds carrying shot was
at its highest.
Pintails, blue-winged teals, and wood
ducks (Aix sponsa) were caught in baited
traps during September at Moscow Bay,
10 miles south of Havana. Examination
of these birds by fluoroscopy revealed an
incidence of ingested lead that was un-
usually high for these species, table 7.
The high incidence may have occurred be-
cause the traps were on a heavily shot-
May, 1959
over area, which, combined with intensive
feeding by the ducks, resulted in exposure
of the birds to unusually large quantities
of lead.
At the trapping site, lead shot was avail-
able equally to the three species, and, in
September, it was unlikely that the birds
were obtaining shot elsewhere. Yet,
among the species, there were differences
in incidence of ingested shot, table 7. Pro-
portionally more pintails than wood ducks
and proportionally more woodies_ than
blue-winged teals carried ingested shot.
Apparently, there is a relationship between
the weight of a duck and its intake of food
and lead. Perhaps under similar condi-
tions of food and feeding, the duck spe-
cies with the largest individuals have the
highest percentages of individuals with in-
gested lead shot, table 7.
Fig. 4.
Illinois Natural History Survey to determine the incidence of ingested lead shot in wild water-
fowl trapped alive as well as in dead and moribund birds picked up in the field. Each bird
was placed in the cone, which was rotated in front of the fluoroscopic screen. This procedure
presented to view more than one plane of the bird’s body and thereby resulted in more precise
location of pellets than was possible in a single plane view.
Peoria, Illinois.)
BELLROSE: LEAD POISONING IN WATERFOWL 25
Cn
In two of the three species, table 7, an
appreciably greater percentage of juveniles
than of adults carried ingested lead shot;
in the pintail there was little difference in
shot incidence between age groups. In
the pintail, blue-winged teal, and wood
duck, there were only slight differences
between the sexes with respect to inci-
dence of shot, but, in the lesser scaup, pro-
portionally twice as many drakes as hens
carried ingested shot, table 7. The lesser
scaups represented in table 7 were trapped
on another area near Havana in April,
1953.
The seasonal incidence of ingested lead
shot among mallards trapped at the Chau-
tauqua National Wildlife Refuge during
the fall months of 1949 and 1950 is shown
in table 8. Most of the mallard groups
fluoroscoped early in the season had a
An X-ray head and fluoroscopic screen used at the Havana laboratory of the
(Photograph from the Journal-Star,
fae]
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Ittinors NATURAL History SurvEY BULLETIN
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May, 1959
lower percentage of individuals with in-
gested shot than had groups fluoroscoped
later in the season. The decline in the in-
cidence of ingested shot among _ birds
fluoroscoped in the December 20-24 pe-
riod may have occurred as a result of the
freeze-up of the lakes a week or two be-
fore, or as a result of a rapid die-off of
lead-poisoned birds in a period of cold
weather.
Erratic changes in incidence of ingested
shot from period to period were evidence
of population changes brought about by
the arrival and departure of migrating
mallards that varied greatly from flight
to flight in the amounts of ingested lead
they carried.
A few waterfowl in Illinois have been
fluoroscoped in late winter or spring for
evidence of ingested lead shot. Ingested
shot was found in a moderate percentage
of the lesser scaups examined, table 7. It
was found in a very small percentage of
the birds in one group of pintails; it was
not found in another group of pintails nor
in a sample of Canada geese, table 9.
Many ducks in other states have been
fluoroscoped for evidence of ingested lead
shot, table 10. In Michigan, small per-
centages of mallards and black ducks
(Anas rubripes) were found to carry in-
gested lead during the winter and spring
months. Lesser scaups that were fluoro-
scoped during the spring months contained
BELLROSE: LEAD POISONING IN WATERFOWL
257
no ingested shot. Examination of winter-
ing ducks (most of them black ducks, can-
vasbacks, lesser scaups, and redheads) by
Hunt & Ewing (1953:362) along the De-
troit River disclosed that less than 4 per
cent of 7,700 ducks fluoroscoped had lead
in their gizzards.
Of more than 1,000 ducks, most of
them black ducks, that were fluoroscoped
during the fall, winter, and spring months
in New York, only a very small propor-
tion carried ingested lead, table 10. Only
a small proportion of mallards trapped
during the winter months in South Da-
kota had lead in their gizzards.
Of six species of ducks fluoroscoped
during the summer months in the Great
Salt Lake Basin of Utah, the mallard was
the only species in which a moderately
large proportion of individuals carried in-
gested lead, table 10.
An astoundingly large proportion of the
mallards, pintails, and redheads, and a
smaller proportion of the blue-winged
teals fluoroscoped during the summer at
Delta Marsh, Manitoba, carried ingested
lead shot, table 10. All of the redheads and
most of the blue-winged teals and pin-
tails were juveniles. The findings of
Elder (1950:501) agree with Illinois
data in indicating that juvenile ducks are
more likely to ingest lead shot than are
adults; at Delta, over twice as large a
percentage of juveniles as of adult mal-
Table 8.—Periodic incidence of ingested lead shot among mallards trapped at the
Chautauqua National Wildlife Refuge near Havana, Illinois, during the fall months of 1949
and 1950.
NuMBER OF Ducks NuMBER OF Ducks Per Cent or Ducks
P FLUOROSCOPED WirH SHor WirH SHor
ERIOD
1949 1950 1949 1950 1949 1950 Average
Och 26-30) 2s 129 2 1 4.65 50.00 5.34
Oct. 31—Nov. 4... 224 153 6 SEs) 3.92 eh!
Nove 5=9..055.¢- 161 408 14 19 8.70 4.66 5.80
Nov. 10-14....... 194 435 12 32 6.19 7.36 7.00
Novel 5=19 3 a. 361 382 22 44 6.09 BEE52 8.88
Nov. 20-24....... 385 333 30 33 7.79 9.91 Sed/,
INows25—29... oe 352 194 40 22 11.36 11.34 11.36
Nov. 30-Dec. 4... 150 69 11 20 TESS 28.99 15.07
Weer 5-905 se 274 24 30 bi 10.95 45.83 13.76
Dec. 10-14....... 54 3 i PEt 33.33 12.28
Wee, W5=19.. 2... I) 12, D Deon 16.67 23.53
Dec. 20-24....... 64 54 6 10.94 TU 11.02
Total. ...|, 2,370 2,069 192 190
AV ELAR One eer nce 8.10 9.18 8.60
258 Ittrnois NATURAL History SuRVEY BULLETIN
lards were found with lead in their giz-
zards, and over three times as large a per-
centage of juvenile as of adult pintails
carried ingested lead.
On other breeding ground areas—
Whitewater Lake, Manitoba, and Eye-
brow Lake, Saskatchewan—Elder (1950:
501) examined 3,300 ducks during the
summer months of 1948 and 1949 and
found that less than 1 per cent of the in-
dividuals of any species carried ingested
lead. Undoubtedly, most breeding ground
areas would show a low incidence of in-
Vol. 27, Art. 3
gested shot among waterfowl. The Delta
Marsh, which is one of the most heavily
shot-over areas in Canada, is an excep-
tion.
Shot in Ducks Bagged by Hunters
With the help of wildlife biologists in
almost every state of the Union and some
Canadian provinces, the Illinois Natural
History Survey obtained data on the in-
gested lead shot found in the gizzards of
more than 40,000 waterfowl bagged by
hunters in the autumn and early winter
Table 9—Incidence of ingested lead among pintails and Canada geese trapped and fluoro-
scoped in Union County and pintails trapped and fluoroscoped in Henderson County, Illinois,
1952 and 1953.
i —————————————— —_
SPECIES PLACE YEAR MontTH Ee Wotan
Pintail..............] Henderson County 1952 April? ih 42 0.24
Pintail..............]| Union County 1953 February 95 0.00
Canada goose....... | Union County 1953 February 61 0.00
Table 10.—Incidence of ingested lead shot among waterfowl fluoroscoped in several areas
and at different seasons during the period 1941-1954.
NuMBER Per Cent
AREA SPECIES YEAR Season | Fiuoro- |WitH INGESTED
SCOPED SHOT
Michigan*.........| Mallard and black
ducks )2ts bak oe nts AGAL, 1942 Winter 682 152
Mallard and black
duck +. ec ne a OAL 1942 Spring 182 0.4
Lesser scaup.......-- | 1941, 1942 Spring 105 0.0
New Yorkt......-.| Black duck. 1949-1953 Fall, 1,063 0.1
Winter,
Spring
Other species..... ... My oe aaa 144 0.0
South Dakotat....| Mallard. ... 1950-1954 Winter 3,455 31
WWigalieen. a: siren: Mallard... 25... 1950, 1951 Summer 122 5.7
Gadwall.... 1950, 1951 Summer 16 0.0
Baldpate...:.-/.- 1950, 1951 Summer 98 0.0
ANEAN sect bs ee 2 1950, 1951 Summer 2,199 0.6
Green-winged teal. . 1950, 1951 Summer 213 0.0
Shovelenicci es aac: 1950, 1951 Summer 77 1.3
Manitobatihs.-) saul Mallard nc 2.) 1948, 1949 Summer 537 18.4
| 2th ate (ees ahem ea 1948, 1949 Summer 391 15.6
Blue-winged teal... 1948, 1949 Summer 549 4.9
Redhead......-.... 1948. 1949 Summer 52. 48.1
*From ‘‘Waterfowl survey of Saginaw Bay, Lake St. Clair, Detroit River, Lake Erie and the marshes adjacent
P-R Project 13-R, Michigan Department of
to these waters,”
by Herbert J. Miller.
Conservation, January 1, 1943.
+From letter of February 18, 1954, by Donald D. Foley, New York Conservation Department.
+From letter of March 7, 1955, by Ray Murdy, South Dakota Department of Game, Fish and Parks.
** Summarized from Heuer 1952
+7Summarized from Elder 1950:501.
Unpublished final report,
,
“
4
}
f
’
May, 1959
BELLROSE: LEAD POISONING IN WATERFOWL
299
Fig. 5.—Shot pellets from the gizzards of wild ducks bagged by hunters. Pellets 4 and B
were from the same gizzard. Pellet 4 entered the gizzard lumen from the charge that killed
the bird. Pellet B had been ingested previously. Pellet 4 exhibits craters caused by the strik-
ing of this pellet against others in passage through the shotgun barrel. Pellet B has been some-
what smoothed by abrasion in the gizzard; under magnification, the surface of this pellet shows
pitting and flaking. Pellet C, another ingested pellet from another gizzard, shows surface
erosion resulting from the action of digestive juices in the gizzard.
months of the period 1938-1953. Lead
pellets, two ingested and one not ingested,
are shown somewhat magnified in fig. 5.
The number of shot pellets and the spe-
cies of ducks represented were known for
each of 36,145 gizzards; data from these
gizzards were used in an analysis of the
incidence of shot among each of the prin-
cipal kinds of waterfowl of North Amer-
ica, table 11.
Variations in Shot Incidence
Among Species.—The incidence of
ingested lead shot was about seven times
as great among ducks as among geese, ta-
ble 11. Less than 1 per cent of the (an-
ada geese and less than 3 per cent of the
blues and snows were found to have lead
in their gizzards; the numbers of shot pel-
lets per gizzard were exceedingly low.
There was a wide range in incidence
of ingested shot among the different kinds
of ducks, table 11. Kinds in which less
than 2 per cent of the gizzards contained
lead were bufflehead (Bucephala albeola),
green-winged teal, mergansers (Mergus
spp.), wood duck, shoveler, and gadwall.
Kinds in which lead was found in more
than 2 and less than 5 per cent of the giz-
zards were blue-winged teal, baldpate,
and common goldeneye; in more than
5 and less than 10 per cent, ruddy duck,
mallard, black duck, and pintail; in more
than 10 per cent, canvasback, lesser scaup,
redhead, and ring-necked duck.
It is apparent that, with the exception
of the last-named group, all of which be-
long to the genus Aythya, there is no re-
lationship between the incidence of shot
and the phylogeny of the birds.
Shillinger & Cottam (1937:402) be-
lieved that ingestion of lead shot was re-
lated to the availability, or lack of availa-
bility, of grit, for they stated : ““While lead
poisoning is widely distributed throughout
all sections of this country, evidence
seems to indicate that it is more severe in
those sections where there is a deficiency
of available gravel that may serve as grit
in the gizzard of the birds.”
Tener (1948:38) believed grit prefer-
ences to be a factor influencing shot inges-
tion by waterfowl. He noted that only
fine sand appeared in baldpate and green-
winged teal gizzards, and that a large
proportion of the gizzards of these species
contained no shot. He speculated that
lead pellets were too large to be selected
as grit by these species.
If waterfowl were prone to pick up lead
shot for grit, then it would seem reason-
able to expect many species which pick up
large-sized grit particles to have ingested
more shot pellets than the numbers re-
corded for them in table 11. Ducks that
commonly pick up grit particles that are
larger than a No. 6 shot and that show a
low incidence of shot are wood duck, buf-
flehead, and common goldeneye. The giz-
zards of geese contain quantities of large
grit particles, but the incidence of shot
among geese is lower than among ducks,
table 11.
Vol. 27, Art. 3
Ittinois NATURAL History SuRVEY BULLETIN
260
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May, 1959
Evidence that the size of grit usually
ingested by individuals of a species of
water bird is not related to the ingestion
of shot by individuals of that species is ap-
parent from a study of the stomach con-
tents of 792 coots (Fulica americana).
Lead shot was found by Jones (1940:11)
in only 12, or 1.5 per cent, of 792 stom-
achs. Gravel was found in all but 7 of the
792 stomachs and averaged 33 per cent
of the gross contents. The low incidence
of shot in the stomachs was attributed by
Jones to the habit that the coots have of
dabbling for food on the surface of the
water as well as to their inability to sift
through bottom material with their
chicken-like bills. Yet it is reasonable to
assume that they could pick up shot pel-
lets with their bills as readily as they
could pick up grit particles.
Food preferences and feeding habits of
the various species of waterfowl appear
to be largely responsible for the differ-
ences in the incidence of ingested shot
among the species. The following discus-
sion of feeding habits tends to support
this thesis. Figures in parentheses fol-
lowing the name of a kind of waterfowl
indicate the percentage of gizzards in
which shot pellets were found, as pre-
sented in table 11.
Shovelers (1.60) and _ green-winged
teals (1.36) feed on the surfaces of mud
flats and marsh bottoms. Gadwalls (1.84)
and baldpates (3.17) feed upon the veg-
etative parts of aquatic plants and seldom
have occasion to dig into the bottom soil
where shot pellets are present.
Wood ducks (1.58) feed so extensively
on fruits of woodland plants (Martin,
Zim, & Nelson 1951:65) that they sel-
dom puddle or sift through lake and
marsh bottoms for food. Mergansers
(1.46) feed principally on fish and there-
fore have less occasion to ingest shot than
have species which search through bottom
materials for food.
Common goldeneyes (3.52) and buf-
fleheads (0.69) are prone to frequent
large, open bodies of water, over which
there is little shooting, and more than 70
per cent of their food is made up of ani-
mal life, especially crustaceans and insect
larvae (Cottam 1939:132). These ani-
mal organisms are found at or near the
surface of the bottom; ducks feeding upon
BELLROSE: LEAD POISONING IN WATERFOWL 261
them need not sift bottom material, as do
those feeding upon the tubers, rootstocks,
and seeds of aquatic plants.
Mallards (6.79) and pintails (8.87)
do considerable feeding in grainfields,
which may somewhat reduce their expo-
sure to deposited lead shot. However,
when feeding in lakes and marshes, they
are, for the most part, active in heavily
shot-over areas. Moreover, their habit of
puddling deep into the bottom soil for
seeds exposes them to deposited lead more
frequently than other dabbling species, ex-
cepting the black duck, which behaves sim-
ilarly.
Redheads (13.57), ring-necked ducks
(14.18), canvasbacks (11.84), and lesser
scaups (13.09) normally dive for food in
comparatively shallow water in_ their
search for seeds, tubers, and rootstocks of
aquatic plants. Plant items, according to
Cottam (1939:53), make up 60 to 90
per cent of the food of these ducks. The
combined effect of feeding in heavily shot-
over waters and the types of food taken
result in a higher frequency of ingested
shot pellets in this group of diving ducks
than in any other group or species of wa-
terfowl.
Regional Variations in Shot Inci-
dence.—The incidence of ingested lead
shot among ducks of 11 important species
was determined for each of the North
American flyways by examination of 39,-
610 gizzards collected in the fall and
early winter months of 1938-1954, table
1%
The incidence of ingested lead was
lowest in ducks of the Central Flyway.
There were only small differences be-
tween the figures for North Dakota,
South Dakota, Nebraska, and Colorado;
for Texas the incidence of shot was sev-
eral times as high as that for any other
state in the flyway. In the Dakotas, only
the shoveler, redhead, and canvasback
showed an appreciable incidence of in-
gested lead, whereas in Texas most spe-
cies showed a high incidence of such lead.
The incidence of ingested shot pellets
was about twice as high among ducks of
the Atlantic Flyway as among those of
the Central Flyway, table 12. The inci-
dence figures were higher for Massachu-
setts, North Carolina, and South Carolina
and Georgia than for Maine, New York,
262
a group of other Atlantic states, and Flor-
ida. With few exceptions, waterfowl giz-
zards from the above states came from
areas near or on the Atlantic Coast; most
samples from New York and Florida
Ittino1s NATURAL History SuRvVEY BULLETIN
Vol. 27,-ArkS
were from the interior areas of those
states. Species in the Atlantic Flyway
with the highest incidence of ingested lead
shot were the pintail, canvasback, and
redhead. Next in order were the mallard
Table 12.—Regional incidence of ingested lead shot among ducks of 11 important species;
the United States and Canada, 1938-1954.
Matiarpd |Briack Duck} GaADWALL BALDPATE PINTAIL
a>) is} ae] ry 5 = »
ae 52) ee l\ae2| delet lta lst) see
a: os aa ao: a's on
fel S| se) eo | €e.e | 88.) ao ee
zal\eelza|f2|2za\/S2 1/24) 82 | 24) ce
ATLANTIC
Mia inet ace, ade eminent 7 | 14.3 725 4.8 1 0.0 ee 13 15.4
Massachusetts........-..| -----Je+.-.- {l,268 TES) SS 4} 0.0 a0 Re 48
INewa ionic can oan Wal 6.5 425 4.5 1 0.0 12 | 0.0 32 12.5
Pennsylvania, New Jersey,
Delaware, Maryland,
WiReiNta Nee 59 7 207 2.9 14 | 21.4 5 0.0 13 61.5
North Carolina.......... 9 Tal ER oe oO 30 | 10.0 2 fall eto 50 4.0 18 0.0
South Carolina and
Gedteian sa atiewe asst Wi 9.1 66 | 13.6 95 32 38 0.0 56 10.7
Wionida teen eer ie eke 3] 0.0 5 0.0 15 0.0 15 | 13.3 15 | 20.0
TEBTALR oes ee NE ce PE OU eee os COL nee 126 Seis ele: 1 ee
Averase: an2> st incsiclhaee (ie as Be 6.1 ie i aS oe cn.
MissIssIPPI
Minnesota..............| 371 | 12.4 9} 11.1 18 5.6 23 | 0.0 102 12.7
Wlittigne cee er ee SRO a9 27 | 18.5 109 | 0.0 162} 00} 951 5.9
Tindiatiatce sisal a ee | 2385 93 | 28.0 13 | 0.0 17 5.9 34 11.8
Missouri.......-.-.-....{| 415 2.4 4 0.0 8 | 12.5 8 0.0 35 2.9
Tennessee...............| 696 | 11.6 17 5.9 174 1.2 38 5.3 102 4.9
Arkansas...............|3,494 2 AE ae SR rel Awe be Bid Lo See
Wouisiana. 2228. oe. |) B19) 15.1 7 | 0.0 17 eee: 38 Ded 160 | 28.1
Ota acta ery ALO OU cps eta) uate seen 449 ...| 286 . | ([3040 | een
IANPRAE Cy # See ere ane c| meee S24 eae ol 21e 0 cay 1260). cn a ee 9.0
CENTRAL
North Dakota.........../1,186 1.9 171 0.6 74 1.4 161 0.6
South Dakota...........|1,123 2.6 9] 0.0 13 | 0.0 26 0.0
INebraskateres ter ee a Uae oD a oni 2! 0.0 63 | 0.0 8 0.0
@oloradon wet el 2OON i Oe 7 Ea 1 leans Wi lite Shiga re
Me xas sn weaten Seale Aen 65 | 15.4 18 | 11.1 25 | 0.0 51 15.7
POW eS ee tee SR OLS, eI? 200 Steal UZ One (uate 246 a
Average: Staaten batensse Our rete) der bititorsee 0..61|Sgeae K
PAaciFic
British Columbia........| 138 | 17.4 2! 0.0 37 | 0.0 55 16.4
Washineton.. 0. 5. .<..-.'s| , 398 5.0 6 0.0 120 1.7 118 11.0
Wresonties 2. Soe ns! 214 | 4.7 Os) “040 S7y| 7207) 0z 7.8
Tdahose ete soe es ee [23502 5.8 ee Gea 29 | 3.5 23 13.0
Weahwencissen en eel O86 12.5 285 2.1 451 3.8 |2,776 7.9
INevidaleemaos eek. 30 | 20.0 22 0.0 7 0.0 25 12.0
California...............| 697 7.4 158 1.3 | 383 | 4.7 |1,596 9.9
Ota ahaha See ee Sa OG OD ||| ae 482 1,084 4,695 |S
Awe ero Hite gs dia exes leh oe 8.8 Ne 8.
May, 1959
and the lesser scaup, the black duck, and
the ring-necked duck.
The incidence of ingested shot among
ducks of the Pacific Flyway was only
slightly higher than that found in the At-
BELLROSE: LEAD PoIsoNING IN WATERFOWL
263
lantic Flyway, table 12. Ducks near Van-
couver, British Columbia, showed a higher
incidence of ingested shot than did those
in any other area of the flyway. In con-
trast, ducks in adjacent Washington
data are from 39,610 gizzards collected during fall and early winter months from hunters in
GREEN- Rinc-NeEcKED | Lesser To
Mieecen TEAL SHOVELER REDHEAD Bows CANVASBACK | Secatre pea
oS > gal ee 2 tl eet 52a es al age Ue ret Paes el ees
ga) ga) s2|a|e2| a | ee| gal s2| ba | 52) 84 | 52 | ga
€6/9s (eS |Ss| E85 | Ss] EFlSS| SELSS| EE PS] EE] Ps
eel 53 St 5 > | eo S BS | pe = cS et = nt
Za\@e lad | PE | ze) ee | za | SE | 2d | SE | 2a) SS | 28 | Se
| | |
99 | 3.0 90 | 3.3] 40| 7.5] 975] 48
1540 '6.7 oe eae SOOO. ecb 7 2 Seaea ie ages
551 1.8 66| 6.1 91° 0:0:| 27} 18:4} 213) -s.0:) SH) S28
aS) 2.6 |. ral a. mn) 5 | 20.0 4} 0.0| 349} 5.7
Ba =3.0. 68 | 11.8 4| 0.0} 93] 11.8 51 0.0| 301) 83
42 | 2.4 a} 030.4. 61} 9.8 L}) O01). 5 30.0) 460F aa
12} 0.0 54.020 |. 25} 4.0 2} 0.0 6| 0.0} 103} 5:8
204 13 |. Rie en Po jae bo Naga, ee eas ee
Ree: 2 ek Mite tee. PI a Ae Gs iiseb te
13! 00| 40] 2.5] 44/15.9| 79|29.1] 132| 4.6] 88]12.5| 924] 11.8
Panjees} 60) 0.0| 1513.3} 120|17-5| 224| 7.6} 451} 11.5 17,778] 7.3
fes%| 12 | 0.0 7114.3| 50|26.0| 16| 0.0] 20] 20.0| 526| 205
56 | 0.0 9} 0.0 8|12.5| 20] 10.0 3) 0:0)] (32 | 0351 | 598 fa
ees | 18) 11.1 4] 0.0| 266} 14.7| 31] 16.1] 95 | 23.2 \1,504| 9.3
eee shoe | ae Bot) Motes inl eae f eee oe ee ee ee
7} 38} 13-| 0.0 70| 7.1} 7| 0.0} 107] 26.2 |1,005| 14.0
me ise |...) 78 |..2-.-| > 605 |....5.| 403 793|......|15,829
mee £7 4......| 2.0 A ee THO ORY 6 1s EES eee eee
9| 0.0} 29| 0.0] 90} 7.8 SP 9 S21 47 1-9 2 SE boo
mr -o.0| 18] 5.6} 20| 0.0 SP ao | ts) 77. 33 | OO) we
MO 0 |. ....:|.-.. a | | 0.0| 24] 4.2 11,406] 2.8
ee igs ey eden oc OE tte aetna | eeciage Mania, (emer OME. Kr a
11] 9.1 7114.3 | 194 110.3.) 25. -8.0:| 41 25.0)— 30 3.3 |. 430 |- 40.7
meee S54)... | 304 |..ok.| 30 222 |......| 134 | 5,368
Mette | 3.7 |......| 8:9 CA aoa Meee | 7a ieee (ae.
29} 0.0 25) SOTO gina eae fe Dims hE Wh ieee Mee Mie 7a ee Mer ae
125| 0.0 7 | 0.0 6 | 16.7 Seto | 7 13 8|25.0| 998| 4.9
Beet) 110°/90.0)..2..-|.....| 1} 0.0 4|25.0| 4| 0.0| 442] 5.7
7] 0.0 1| 0.0 SAC ECE, eM rem Nite a Wate Mee Oy TS
mor) 0.5) 791 | 1.0| 209] 23.4|......].......| 793111.9} 13| 7.7 17,605] 7.1
i 00| ~46| 2.2 4 | 25.0 1} 0.0 6|33.3} 11 0.0]. 167i. 73
Sener | 9650:| 147 | > 54) 5.6.|......|--....| 68] 21.3] 15] 0.0-]3,895) 6.7
mean9 |... ...\1;507 |......| 274 |.... 6 ed eee eee y al eee Fo | ees
ae 7 Cee We 19.7 |. Ee AG aS etal Gag
264
Ittinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 3
Table 13.—Incidence of ingested lead shot among ducks of 10 species at Hovey Lake, near
Mount Vernon, Indiana;
of 1949, 1950, and 1951.
the data are from gizzards collected in the waterfowl hunting seasons
1949 1950 1951
Peace Number | Per Cent | Number | Per Cent | Number | Per Cent
Examined | With Shot | Examined | With Shot | Examined | With Shot
Mallard. serene eee 90 35.6 56 12.5 61 9.9
Blackcduck<.c.cc Soe coe 39 43.6 18 16.7 19 15.8
Ee tae alt 4g 5 0.0 5 0.0 3 0.0
Baldpate. . RR I AR 4 0.0 3 0.0 4 0.0
Pintail. . a SD ese 17 5.9 6 0.0 3 0.0
Green- winged teal. Seats i 0.0 3 0.0 2 0.0
Shoveler. . eee © 2 0.0 y) 0.0 7 0.0
Ring- necked duck. . Rute 15 46.7 16 5.9 10 20.0
Canvasback.. Ue ee Feit ee 4 0.0 6 0.0 5 0.0
eee ee ee 4 25.0 6 0.0 7 28.6
5 AT Ree ARS CPt rane a a hage er 187 be ice bt 121 ees EZ yay
Averane rumen een ce pale seeo tee Sie SRC ee tiniest ql se 10.7
showed the lowest incidence of shot for
the flyway ; gizzards collected from Wash-
ington were from numerous areas scat-
tered over the state.
Among the ducks of Utah and Nevada,
the incidence of ingested shot was slightly
greater than the average for the flyway.
Among the ducks of Oregon and Idaho,
the incidence figure was below the flyway
average. The incidence figure for the
ducks of California approximated the fly-
way average. The data from Utah were
obtained from material collected at the
Bear River Migratory Bird Refuge; the
data from Nevada were obtained largely
at the Stillwater Wildlife Management
Area. Material from Oregon, Idaho, and
California were from numerous, widely
distributed areas.
In the Pacific Flyway, the incidence of
ingested shot was highest among the red-
head, canvasback, and lesser scaup, lower
in the mallard and pintail, and still lower
in the baldpate, gadwall, shoveler, and
green-winged teal.
The incidence of ingested shot was
Table 14.—Incidence of ingested lead shot among ducks of 12 species in Illinois ; the data
are from gizzards collected in the fall months, 1938-1953, from waterfowl hunters i in the Illinois
and Mississippi river valleys.
Ittino1s River
Mississippi River
SPECIES
Number Number | Per Cent | Number | Number | Per Cent
Examined | With Shot | With Shot | Examined | With Shot | With Shot
Meallird sorte as ok eos 4,784 405 8.47 475 7 1.47
id Tab ene as Can cages 104 0 0.00 5 0 0.00
Baldpate. . 154 0 0.00 8 0 0.00
Pintail. . 920 52 5.65 31 4 12.90
Green- winged teal. 373 3 0.80 27 0 0.00
Blue-winged teal... tc ee 121 1 0.83 8 0 0.00
ine A ee ee 57 0 0.00 3 0 0.00
Wood duck. . A oh ee Te 19 0 0.00 7 0) 0.00
Redhead... .. Pe he 12 2 16.67 2 0 0.00
Ring-necked duck. . oo 113 19 16.81 7 2 28.57
Canvasback.. re Sey a 88 10 11.36 136 i 5.15
Lees Ss eee aa 144 34 23.61 307 18 5.86
Tala epee ee ee 6,889 526 Bagh 1,016 38 ig
IASEEAGR a RNR ecitoup es mec hid nis eae oe 64 Batak og nes 3.74
May, 1959
higher among ducks of the Mississippi
Flyway than among those of any other
flyway, table 12. The highest incidence
figure for the Mississippi Flyway was for
ducks taken in Indiana; these figures were
not typical for the state, as the bulk of the
samples on which they were based were
from Hovey Lake, near Mount Vernon.
Hovey Lake is noted for lead poisoning
losses in waterfowl.
The incidence of ingested shot was
high among the ducks of Louisiana and
Minnesota; moderately high for those of
Illinois, Tennessee, and Arkansas; and
quite low for those of Missouri.
The gizzard collections from Minne-
sota, Illinois, and Missouri constituted
representative samples for those states. In
‘Tennessee, almost all the data were from
Reelfoot Lake. In Arkansas, the giz-
zards were from ducks shot at clubs with-
in a 35-mile radius of Stuttgart. Both
Reelfoot Lake and the Stuttgart area
provide a large share of the duck hunting
in their respective states. Material from
Louisiana was largely from Catahoula
Lake and the Delta region of the Mis-
sissippi River.
In the Mississippi Flyway, the inci-
dence figure for lead shot was higher in
the black duck than in any other species,
but the data were biased by the large
number of black duck gizzards taken at
Hovey Lake, Indiana, where the _inci-
dence of lead was extremely high. It was
very high in the ring-necked duck, lesser
scaup, and redhead; it was moderately
high in the pintail, mallard, and canvas-
back; it was low in the shoveler, green-
winged teal, gadwall, and baldpate.
The variation in the proportion of
ducks with shot in their gizzards at Hovey
Lake was very pronounced over a 3-year
period, table 13. In 1949, the highest in-
cidence of ingested shot found anywhere
in the United States was recorded at
Hovey Lake, but in 1950 and 1951 the
figure for the area was close to the aver-
age for the Mississippi Flyway.
The extremely high incidence figures
for Hovey Lake in 1949 were probably
influenced by the hunters’ kill of a large
number of ducks affected by lead poison-
ing. Up to the end of the 1949 hunting
season, the Indiana Department of Con-
servation permitted hunters to jump-shoot
BELLROSE: LEAD PoIsONING IN WATERFOWL
265
ducks. Since that time, duck hunting at
Hovey Lake has been restricted to blinds.
Jump shooters, in wading the brush-cov-
ered shore of Hovey Lake, hunted a zone
in which ducks suffering from lead poi-
soning were prone to concentrate. Be-
cause the sick ducks had difficulty in fly-
ing, hunters bagged unusually large num-
bers of them.
A reduction in the incidence of ingested
lead occurred in the mallard in 1951 at
Hovey Lake, evidently because high wa-
ter, which raised the lake level during the
latter part of the hunting season, made
lead shot less easily available to this duck.
The increased depth failed to reduce the
ingestion of shot by diving ducks.
A comparison of the incidence of in-
gested shot in ducks taken along the IIli-
nois River with those taken along the
Mississippi River in Illinois, table 14,
disclosed a marked difference between the
two areas. The figure for the [Illinois
River is more than twice that for the Mis-
sissippi. The differences in shot incidence
between the two areas were especially
marked in the mallard, canvasback, and
lesser scaup, the only species that were
represented by adequate samples in both
areas.
The Mississippi River normally car-
ries a much heavier load of sediment than
does the Illinois River. Data presented by
Suter (1948, plate 1) for the period
1935-1945 showed that the Illinois River
at Peoria carried an average of 100 p.p.m.
for 300 days per year, whereas the Missis-
sipp! River at Quincy carried an average
of almost 300 p.p.m. for the same number
of days. Apparently lead shot is covered
more quickly in the Mississippi, with its
heavier load of sediment, than in the IIli-
nois.
Periodic Variations in Shot Inci-
dence.—The incidence of ingested lead
shot in mallard populations migrating
through the Illinois River valley in au-
tumn was determined for weekly periods
by examination of 2,499 gizzards collected
from hunters in 1938—1940, table 15.
As in the case of mallards which were
live-trapped and fluoroscoped, table 8, the
percentage of hunter-killed birds that car-
ried ingested shot was: lower early in the
season than late; up to mid-November,
5.7 per cent of the gizzards examined con-
266
tained shot, while after mid-November
7.8 per cent contained shot.
The incidence of shot among hunter-
killed birds, table 15, varied from week
Table 15.—Periodic incidence of ingested
lead shot among mallards in Illinois; the data
are from 2,499 gizzards collected from water-
fowl hunters in the Illinois River valley, 1938-
1940.*
NuMBER OF
PERIOD GIzzARDS Per Cent
EXAMINED Wirxu SHot
Oct. 11-17... 82 2.44
18-24... 227 7.05
25-3 ibs. a 456 3.73
Nove nd / anes Sui 8.75
8-14.... 296 4.73
15-21... 455 7.69
Ds) Rages aes 324 9.88
Nov. 29-Dec. 5. 216 7.41
Dec. 6-12.. 66 0.00
*Data from food habits study of Illinois ducks by
Harry G. Anderson, June 1, 1939—June 30, 1941, leader
of Federal Aid Project 2-R, Illinois Natural History
Survey and Illinois Department of Conservation, co-
operating.
It~tinois NaturAL History SurRvEY BULLETIN
Vol. 27, Art23
Bear River Migratory Bird Refuge, Utah,
are given in table 16. Ingestion of shot
was uncommon during the summer
months, except for the mallard in 1951,
but it was relatively common for several
species in the fall.
It is evident that much of the lead in-
gested by ducks in Illinois and in Utah
had been fired from hunters’ guns in the
same year it was picked up by the ducks.
Apparently, much of the shot fired by
duck hunters during a hunting season
penetrates sufficiently deep into lake and
marsh bottoms by the following summer
to be out of reach of feeding waterfowl.
Data in table 11 and those reported by
Shillinger & Cottam (1937:401) permit
a comparison of the incidence of ingested
lead among waterfowl in two periods sep-
arated by more than 20 years. According
to Arnold L. Nelson (letter, December
13, 1955), 77 per cent of the gizzards re-
ported on by Shillinger & Cottam were
collected in the period 1908-1916; all
gizzards represented in table 11 were col-
Table 16.—Incidence of ingested lead shot among ducks of seven species at or near the
Bear River Migratory Bird Refuge, Utah, summer and fall, 1950 and 1951. Summer data are
based upon fluoroscopy of ducks apparentiy suffering from botulism; fall data are from duck
gizzards collected from hunters.
SPECIES
WIR eaten! es Rae BUR Sm myer Pi ere kite
Gad allt eee en enti eee NU er: ne ana NS
Brcelrsette eee ree ee eens a gmt dcr Mi Enea a
AAS ea hae Nlhreld Rapee a eRe
Green-wingediteal: o..5 1 0i tube eows.. ook
Sears pet 1) ots rate ger anne
| PREYS HA Cee Ys Weil ane Ly reel I AL) nN
IVER AGS ssi tals Shaan nee Cec orate ee eerie ARR
1950 1951
Per Cent With Shot | Per Cent With Shot
Summer Fall Summer Fall
3.2 on 14.3 8.9
0.0 0.7 Oe PD
0.0 3.2 0.0 3.9
0.6 10.0 0.6 5.8
0.0 0 2 0.0 0.2
1.8 0.9 0.0 1.1
0.0 PALL 0.0 pcyee?
0.8 6.7 0.7 5.6
to week as in live-trapped mallards, table
8. In Minnesota, as in Illinois, a pro-
nounced weekly variation in the incidence
of ingested lead has been reported (Reid
1948:126). These periodic variations in
the incidence figures appear attributable
in part to population shifts associated with
migration.
Figures on the occurrence of ingested
shot among waterfowl taken during the
summer and fall months at or near the
Table 17.—Incidence of ingested lead shot
among mallards taken in two different periods
of years in the Illinois River valley; data are
from gizzards collected from hunters.
NuMBER OF
YEARS GIzZARDS Numser | Per Cent
ExamMInepD | Wirtu Snort | Wiru SHor
1938-1940] 2,371 165 6.96
1948-1950} 2,005 240 11.97
May, 1959
lected in the period 1938-1953. The
comparison is limited to six species of
ducks—mallard, pintail, redhead, ring-
necked duck, canvasback, and lesser scaup
—which are listed in both periods.
In five of the six species (the exception,
lesser scaup), the incidence of ingested
shot recorded for the 1938-1953 period,
table 11, was much higher than that for
the earlier period. The per cent of giz-
zards containing shot increased for the
five species as follows: mallard from
2.41 to 6.79, pintail from 1.14 to 8.87,
redhead from 3.14 to 13.57, ring-necked
BELLROSE: LEAD POISONING IN WATERFOWL
267
duck from 3.29 to 14.18, and canvasback
from 9.77 to 11.84.
Shillinger & Cottam (1937:401) re-
ported lead in 39.42 per cent of the lesser
scaup gizzards, but over one-third of
their sample was from the vicinity of Mar-
quette, Wisconsin, where shot was found
in 76.5 per cent of the gizzards. The
large sample from an atypical area mate-
rially biased the results.
The incidence of ingested lead among
mallards in the Illinois River valley dur-
ing two different periods—1938—1940 and
1948—1950—is shown in table 17. In a
Table 18.—Incidence of various ingested shot levels found among ducks of seven species;
data are from 2,184 duck gizzards (each of which contained ingested lead) collected during the
fall and early winter months from hunters in North America, 1938-1954.
(By shot level is
meant the number of ingested shot pellets found in a gizzard.) For each species are given
the number and per cent of ducks represented at each shot level.
1 PeEL- 2 PEL- 3 PEL- 4 PeEL- Seer 6 Pet- | Over 6 T
LET LETS LETS LETS LETS LETS PELLETS eae
SPECIES eu Rae les ies ica siccs uel Re Wiss | ee elie . w
cee bee ote rosa ools | oalee he ens
3 5 } ay 5 5 3 5 B) 3} 3 5 5 G 3 i
PZ || foby Neg MIS |g | fale ae foi | Za fom Ih ez | fet Pee | rau, NN Ie aw
Mallard........| 757/65.3] 194)16.7} 80] 6.9} 31) 2.7] 24] 2.1 9| 0.8) 64) 5.5/1,159/100.0
Black duck..... 120/65.6| 27/14.8) 15} 8.2 6) 3.3 1) 0.6 3) 1.6} 11] 6.0} 183/100.0
Bintan se el 2eliGO.O) Suil2e 7 27) 6.7) 19 4: 7 19 350 1} 0.2} 51/12.7| 402]100.0
Redhead........ 56/69.1) 11/13.6 4, 4.9 0) 0.0 il] ill} il 8} 9.9 81)100_.0
Ring-necked
aherCle. Se eeereme 6565.7} 10]10.1 9) 9.1 2) 2.0 0} 0.0 A OW aaah 99|100.0
Canvasback.....| 107/74.3} 13) 9.0} 12) 8.3 4| 2.8 1] 0.7 Sera 4, 2.8) 144/100.0
Lesser scaup.... 67/57.8) 19)16.4) 12/10.3 3) 265 0} 0.0 1] 0.9} 14)12.0} 116|100.0
center esl CASO | TOO), uc) OS). i OOo Tal Olas ok MOOI b, 2 || Qe OA Ih kes, al
SCI eee Sea Ot leee all4te9 TV Bio Solo - 1.8 On9 Tele se LOOLO
Table 19.—Incidence of high levels of ingested lead shot (20 or
among ducks of seven species; data are from gizzards collected from
more pellets in gizzard)
North American hunters
in the autumn and early winter months, 1938-1954.
NumBer OF Gizzarps | NuMBER OF PELLets | Numper |Per Centr or Gizzarps
SPECIES Wir PeEtvets IN INDIVIDUAL OF Wiru 20 or More
GIzZARDS Ducks Pe.iets Eacu
MWWallandya. <2 0s. « 4: 1,159 20, 60, 93, 107, 137 5 0.43
Black duck...... 183 MS 1 0.55
Pimizevtl 5 6 aes 402 PAO), PAD), PIA GIB). PIS) Bhsts 9 2.24
48, 60, 110
Redheads...« 452 81 RE NERO fa Bina ee ee 0 0.00
Ring-necked duck 99 Sil, 7 (S 3 3.03
Canvasback...... 144 53 1 0.69
Lesser scaup..... 116 21, 21, 43, 46, 52, 58, 8 6.90
64, 172
TNOWAIGS cues 2,184 27 aT AC OTD Ae ee
Sf SME, ao ae Bharti: shares 1.24
268 Ittrnoris NaturRAL History SurvEY BULLETIN
decade, the incidence figure for Illinois
mallards almost doubled.
Increases in the percentage of water-
fowl ingesting lead have paralleled in-
creases in the number of waterfowl] hunt-
ers. Because there is expectation that the
number of duck hunters will continue to
increase, it can be anticipated that lead
poisoning will become a greater hazard to
waterfowl] than it is at present.
Incidence of Various Shot Levels.
—The incidence of various levels of in-
gested lead shot found among ducks of
seven species in North America in the
autumn and early winter months of
1938-1954 is shown in table 18 and fig. 6.
(By level of ingested lead shot, or shot
level, is meant the number of ingested
shot pellets found in a gizzard.) The va-
rious shot levels have an important bear-
ing on the rate of mortality in ducks for,
as will be shown later, the larger the num-
ber of ingested shot pellets per duck, the
higher is the death rate, other factors be-
ing equal.
Of 2,184 duck gizzards that contained
lead when collected from hunters in many
parts of North America in 1938-1954,
i
fa
RRS DAD ADS DROS NDAL A ORDEN ANAD
tek SN NE RE AN Re ie
PER CENT OF SPECIES
Seer acc oa aie
i
yy
Y
YQ
Bg
ee Yy)
ea Vy
pate Yj
ae G
bo G
fee Y
ae Y)
be Y
oe Yy
oe Y
aa Z
EY
se Yj
/
Y
Py Y)
LY
Ly
A
g
ny
PELLETS
pau
. WZ
PELLET,
Vol. 27, Art. 3
64.7 per cent contained one pellet each,
table 18; 14.9 per cent contained two
pellets each. Only 7.4 per cent of the
gizzards containing shot pellets contained
more than six pellets each.
Comparatively few ducks killed by
North American hunters during the fall
months in the period 1938-1954 carried
20 or more ingested shot pellets each, table
19. The maximum number of pellets re-
corded was 172, in a lesser scaup gizzard.
Cottam (1939:39) reported 1 to 58 pel-
lets in individual gizzards of lesser scaups
shot near Marquette, Wisconsin, in April,
1909; Shillinger & Cottam (1937:403)
reported that 179 pellets were found in
the gizzard of a pintail victim of lead poi-
soning.
Data in table 19 indicate that pintails,
ring-necked ducks, and lesser scaup ducks
are more likely to have large numbers of
pellets per gizzard than are the ducks of
other species.
The large numbers of shot pellets found
in gizzards of pintails, ring-necks, and
lesser scaups are probably a reflection of
the ability of these species to tolerate the
toxic effects of lead, as well as a reflection
MALLARD
BLACK DUCK
PINTAIL
REDHEAD °
RING-NECKED DUCK
CANVASBACK
LESSER SCAUP
3 PELLETS
Fig. 6.—Incidence of four levels of ingested shot found in gizzards of ducks of seven species
in the autumn and early winter months of 1938-1954. Data are from table 18 and represent
ducks shot by hunters in many parts of North America.
May, 1959
of their proclivity to pick up large num-
bers of pellets. For example, pintails are
only slightly more prone than mallards to
ingest shot, table 11, but the percentage
of gizzards containing 20 or more shot
pellets each was almost six times as great
in pintails as in mallards, table 19. The
percentage of gizzards containing ingested
shot was about the same in_ redheads,
ring-necked ducks, canvasbacks, and lesser
scaups, table 11, but larger percentages of
BELLROSE: LEAD POISONING IN WATERFOWL
269
LEAD IN WILD MALLARDS
DOSED AND RELEASED
Certain effects of lead poisoning on
mallards in the wild were determined by
the following experiment. In the au-
tumns of 1949, 1950, and 1951, several
thousand migrating mallards were trapped
at Lake Chautauqua. Some of these ducks
were dosed with either one, two, or four
No. 6 shot pellets each, then banded, and
Fig. 7.—Penned mallards, dosed with lead shot, feeding upon coontail, apparently one of
the best vegetable foods for alleviating the effects of ingested lead.
gizzards with 20 or more shot pellets each
were found among the ring-necked ducks
and scaups.
As shown by Jordan & Bellrose (1951:
18), the ability of ducks to survive lead
poisoning is influenced by the physical
form of the food consumed. The higher
survival rate of pintails than of mallards
may be related to the greater numbers of
small seeds and the paucity of corn in the
diet of the pintails. Lesser scaups, which
consume at least twice as much animal
life per bird as any other ducks listed in
table 19 (Cottam 1939:53), apparently
can tolerate lead to a greater degree than
the ducks of other species. Thus, it ap-
pears that animal matter is more favora-
ble than vegetable matter to survival of
ducks that have ingested lead, and that
various forms of vegetable matter differ
greatly in their effects on birds that have
ingested lead, fig. 7.
released. Other ducks trapped at the same
time were banded and released, undosed,
to serve as controls.
In 1949 and 1950, the trapped mal-
lards were taken to the Havana field lab-
oratory of the Illinois Natural History
Survey, where they were fluoroscoped be-
fore being banded and released. Ducks
known to carry ingested lead when
trapped were not included in the experi-
ment. In 1951, when the X-ray unit was
being repaired and could not be used for
fluoroscopy, undoubtedly some ducks car-
rying ingested lead when trapped were
released as dosed or control birds. The
number of these was, of course, unknown
but it was probably relatively small.
In 1949, only adult mallard drakes
were included in the experiment. In 1950
and 1951, both adult and juvenile drakes
and, in 1951, hens also were included in
the experiment.
270 ILLINOIS NATURAL
In 1949, 559 mallards were dosed with
one No. 6 shot pellet each before being
released, and 560 lead-free birds were re-
leased, undosed, to serve as controls. Of
the 1,172 mallards used in the experiment
in 1950, 391 were dosed with one No. 6
pellet each, 392 were dosed with two No.
6 pellets each, and 389 were released, un-
dosed, to serve as controls. In 1951, 2,016
mallards were used as follows: 504
drakes were dosed with one No. 6 pellet
each, 504 drakes were dosed with four
No. 6 pellets each, 501 hens were dosed
with one No. 6 pellet each, and 507 drakes
were undosed.
Because of the considerable cost of han-
dling the mallards used in this experi-
ment, it was deemed advisable to obtain
reports of as many band recoveries as pos-
sible from the hunters who shot the birds.
As an inducement to hunters to report
bands, 759 ducks released in 1949 were
banded with U. S. Fish and Wildlife
Service reward bands (which provided a
certificate and booklet for each person re-
turning one or more bands); 360 were
marked with standard Fish and Wildlife
Service bands. In 1950 and 1951, each
mallard in the experiment was banded
with a special $2.00 reward band, as well
as the standard U. S. Fish and Wildlife
Service band. The ratio of reward to
standard bands recovered was more than
2 to 1 (Bellrose 1955).
Bands recovered from the mallards
used in the experiment revealed signifi-
History Survey BULLETIN
Vol. 27, Art. 3
cant differences between the dosed and
the control birds. The dosed birds, some
of which became afflicted with lead poi-
soning, had (1) a greater vulnerability to
hunting, (2) lower ability to migrate, and
(3) higher over-all mortality rates in the
first year after being banded and released
(from time of banding through the fol-
lowing August).
Effect of Lead on Vulnerability
to Hunting
That mallards carrying lead in their
gizzards were more vulnerable to hunting
than were lead-free mallards is shown in
tables 20-23. In 1949, mallards dosed
with one No. 6 shot pellet each were 1.84
times as vulnerable to hunting as were the
controls, table 20. In 1950, they were
1.19 times as vulnerable, and, in 1951,
they were 1.41 times as vulnerable. The
year-to-year variation in vulnerability
probably resulted from differences in food
and weather conditions.
Unfortunately, the effect of two and of
four No. 6 shot pellets for each bird was
evaluated for only 1 year. In 1950, the
kill rate of mallards dosed with two No.
6 shot pellets each was 1.89 times as
great as the kill rate among the controls,
table 20. A year later, the kill rate
among mallards dosed with four shot pel-
lets each was 2.12 times as great as the
kill rate among ducks not dosed with shot.
During the first 5 days after the mal-
lards in the experiment were released,
Table 20.—Relative hunting vulnerability exhibited by wild drake mallards dosed with
lead and those not dosed, as measured by the ratio between dosed and undosed birds in the
per cent of the banded ducks that were recovered in the season of banding. The 3,807 drakes
used in the experiment were trapped at the Chautauqua National Wildlife Refuge, near Havana,
Illinois, in the hunting seasons of 1949-1951. Some of the birds were banded, dosed with one,
two, or four No. 6 lead shot pellets each, and released. Others, the controls, were banded and
released undosed.
NuMBER NuMBER Per Cent
BANDED RECOVERED RECOVERED RELATIVE. VULREOR Eee
Dosep : ContrRoL
Y Pellet Pellet Pellet
rae Con- Dose Con: Dose Cone Dose
trols ttOlSiis—aae | trols
1 2) 4 1 2 444. 1 os 4 1 Pellet | 2 Pellets | 4 Pellets
1949. .| 560} 559). ..|. 19] 35 SPS9IGL25heaelee eel s4eOONe ‘uo on
1950. .| 389} 391/392) .. 50} 60 95 12.85}15.35|24.23) ....| 1.19:1.00 1.89:1.00 |. a ee
1951..| 507} 504) . |504! 47) 66 99} 9.27/13.10) ... |19.64! 1.41:1.00}. . 2.12:1.00
Total |1 ,456\1,455|392|504| 116\161| 95| 99 |. ee
|
May, 1959 BELLROSE: LEAD PoIsoNING IN WATERFOWL 271
the birds treated with lead were bagged
at about the same rate as the untreated
controls, tables 21-23. During the sub-
sequent 6—10-day period, there was a pro-
nounced increase in the bag of treated
ducks, especially in those dosed with two
or four shot pellets each.
In the dosed wild mallards, the inges-
tion of lead shot did not appear to affect
behavior until after the first 5 days. In
the mallards that were dosed with one
shot pellet each, and that did not die of
lead poisoning, the behavior appeared to
be most severely affected in the 6—15-day
period after ingestion; in mallards that
were dosed with two or four shot pellets
each, and that survived, the period in
which behavior was severely affected ap-
peared to be longer. The data suggest
that most wild mallards that become af-
fected by lead poisoning during the hunt-
ing season either die in the second or third
week following ingestion of shot or they
begin their recovery by the early part of
the fourth week.
Penned wild mallards that were dosed
with lead exhibited weakness and fatigue
during the second and third weeks after
being dosed; these symptoms increased in
severity during the third and fourth weeks
(Jordan & Bellrose 1951:5-6). The keel
bone became prominent, and often the
Table 21.—Relative hunting vulnerability exhibited by wild drake maliards dosed with
one No. 6 lead shot pellet each and those not dosed, as measured by band recoveries in each
of six periods, fall and early winter, 1949-50. The data are for birds trapped, banded, and
released at the Chautauqua National Wildlife Refuge in the fall months of 1949; 559 of the
birds were dosed and 560 were not dosed.
0 PELLET 1 PELLET Tora.
E Number | Per Cent | Number | Per Cent | Number | Per Cent
Days Arrer Dosace of Bands | of Bands | of Bands | of Bands | of Bands | of Bands
Recovered | Recovered | Recovered | Recovered | Recovered | Recovered
in Period | in Period | in Period | in Period | in Period | in Period
as. 5 45.5 6 54.5 11 100.0
6-10. 2 28.6 5 71.4 7 100.0
= 15: 1 Lisi 8 88.9 9 100.0
16-20. 4 S77 <1 3 42.9 7 100.0
21-25. 2 50.0 2) 50.0 4 100.0
20: 4 ee 5 45.5 6 54.5 11 100.0
Total 19 30 49
Table 22.—Relative hunting vulnerability exhibited by wild drake mallards dosed with
one or with two No. 6 lead shot pellets each and those not dosed, as measured by band re-
coveries in each of six periods, fall and early winter, 1950-51. The data are for birds trapped,
banded, and released at the Chautauqua National Wildlife Refuge in the fall months of 1950;
391 were dosed with one pellet each, 392 were dosed with two pellets each, and 389 were
not dosed.
0 PELLET 1 PELLET 2 PELLETS Tora
Days
AFTER Number | Per Cent | Number | Per Cent | Number | Per Cent Number | Per Cent
Dos- of Bands | of Bands | of Bands | of Bands | of Bands | of Bands | of Bands | of Bands
AGE | Recovered | Recovered | Recovered | Recovered | Recovered | Recovered Recovered | Recovered
in Period | in Period | in Period | in Period | in Period | in Period | in Period | in Period
“0-5 : i 8 38.1 6 : 28.6 7 833 21 100.0
6-10. 3 13.0 8 34°8 12 5D) a 98 100.0
11-15. 7 21.9 8 25.0 17 Bei 32 100.0
16-20 . 6 Dee 5 18.5 16 59.3 27 100.0
21-25 4 36.4 3 Dijiee) 4 36.4 11 100.0
26-60 . 5 33).3 ii 46.7 3 20.0 1S 100.0
Total. . 33 37 59 129
272 Ittinois NatuRAL History SurvEY BULLETIN Vol. 27, Art. 3
Table 23.—Relative hunting vulnerability exhibited by wild drake mallards dosed with
one or with four No. 6 lead shot pellets each and those not dosed, as measured by band re-
coveries in each of six periods, fall and early winter, 1951-52. The data are for birds trapped,
banded, and released at the Chautauqua National Wildlife Refuge in the fall months of 1951;
504 were dosed with one pellet each, 504 were dosed with four pellets each, and 507 were
not dosed.
0 PELLET 1 PELLET 4 PELLETS TOTAL
yive ——— eee “= =| —— —j|— -
AFTER| Number | Per Cent | Number | Per Cent | Number | Per Cent | Number | Per Cent
Dos- | of Bands | of Bands | of Bands | of Bands | of Bands | of Bands | of Bands | of Bands
AGE | Recovered| Recovered | Recovered | Recovered | Recovered | Recovered | Recovered | Recovered
in Period | in Period | in Period | in Period | in Period | in Period | in Period | in Period
“i ae 29.0 i 35.5 i 35.5 31 100.0
6-10. 4 11.4 9 35 7 22 62.9 35 100.0
11-15. 7; 16.3 10 2313 26 60.5 43 100.0
16-20 . 6 29.2 8 29.7 13 48.1 OF 100.0
21-25 . 4 30.8 6 46.2 3 28 13 100.0
26-60 . 7 25.0 11 39.3 10 3507, 28 100.0
Total. . 37 br eee 55 ihe a eras 85 esti an Wire
wings of an affected duck assumed a_ cated by differences in miles traveled by
“roof-shaped” or drooping appearance. groups of mallards undosed and by sim-
Symptoms typical of those found dur- ilar groups of mallards dosed with one,
ing the fourth week in penned birds ap- two, or four No. 6 shot pellets each, ta-
pear in wild ducks mainly at times of se- bles 24-26. In 1949, a group of mallards
vere die-offs. Apparently, at other times, dosed with one shot pellet each had a
affected ducks either recover or are taken’ larger percentage of its bands recovered
by hunters or predators in a shorter period within a 50-mile radius of the banding
of time and in a less extreme state of station than had the undosed control
emaciation. group, table 24. In 1950, a group of mal-
: ; lards dosed with one pellet each had a
Effect of Lead on Migration Rate somewhat smaller percentage of its bands
That lead poisoning has a pronounced’ recovered within the 50-mile zone than
effect upon the migration of ducks is indi- had the controls, but a group of mallards
Table 24.—Effect of ingested lead shot on migration of mallards, as measured by distances
traveled by dosed and by undosed birds before they were shot by hunters. The data are for
birds trapped and released at the Chautauqua National Wildlife refuge in the fall months of
1949; 559 of the birds were dosed with one No. 6 shot pellet each and 560 were not dosed.
Figures show for dosed and for undosed ducks the per cent of recovered bands (those re-
covered in year of banding and for which distance data are available) that were recovered
at various distances from the point of banding and release.
0 PELLET 1 PELLET
: Number Per Cent Number Per Cent
Mites From Piace oF Banpinc of Bands of Bands of Bands of Bands
Recovered | Recovered Recovered Recovered
in Period in Period in Period in Period
(LY 0 fame AR anne « LN OURO Set oats eure Meewne ere. 11 55.0 21 60.0
GT OOS at ate eee See ae Eee 1 5.0 1 2.9
LORS SO eae es ee ae os Pe a 2 0 0.0 0 0.0
LS DOO ne eae es recs i ane Tae Bi 4 20.0 1 2.9
DOE SOOR ek eRe ean oid ea ede oa ee ae 3 15.0 5 14.3
SOLA a alt ae a We te Ba Sie NEE RAT a AE 1 5.0 7 20.0
BV ATO EL. 2 FRED rhe, ate ese te aera te 0 0.0 0 0.0
TOBA ea ete Ce Vn eR: 20 100 0 35 100.1
_—
May, 1959
dosed with two pellets each had a much
larger percentage of its recoveries fall
within the 50-mile zone than had the con-
trol group, table 25. In 1951, one shot
pellet for each bird seemed to have little
effect on migration, but four pellets for
each bird greatly retarded migration. Less
than 5 per cent of the bands recovered
from the mallards dosed with four pellets
each were taken farther than 50 miles
from the banding station, table 26.
Manifestly, the weakness and _ fatigue
movement
BELLROSE: LEAD POISONING IN WATERFOWL
of ducks.
273
associated with lead poisoning reduces the
The larger
amount of ingested lead per bird, the
greater is apt to be the reduction of move-
ment by the affected segment of the popu-
lation. In areas where lead poisoning is
of outbreak proportions, it is reasonable to
conclude that the bulk of the sick birds
have picked up shot within their daily
feeding radius, usually less than 50 miles.
the
Conversely, it can be assumed that only a
small percentage of the ducks that have
Table 25.—Effect of ingested lead shot on migration of mallards, as measured by distances
traveled by dosed and by undosed birds before they were shot by hunters. The data are for
birds trapped and released at the Chautauqua National Wildlife Refuge in the fall months of
1950; 391 of the birds were dosed with one No. 6 shot pellet each, 392 were dosed with two
pellets each, and 389 were not dosed. Figures show for dosed and for undosed ducks the per
cent of recovered bands (those recovered in year of banding and for which distance data are
available) that were recovered at various distances from the point of banding and release.
Q PELLET 1 PELLET 2 PELLETS
Mites From PLace oF Number | Per Cent | Number | Per Cent | Number | Per Cent
BANDING of Bands | of Bands | of Bands | of Bands | of Bands | of Bands
Recovered | Recovered | Recovered | Recovered | Recovered | Recovered
in Period | in Period | in Period | in Period | in Period | in Period
USSU eaten tent aed eee na eee 14 58.3 16 B33 33 76.7
SU IO 0s senate a 1 4.2 0 0.0 | 253
VOID SO) eps ieee aie ce een ane 0 0.0 0 0.0 1 2.3
|S 9X0 Oise ate | 4.2 0 0.0 0 0.0
DNS (00 es eae eo ee 1 4.2 3 10.0 5 11.6
UE AOC may es tot ace 7 29.2 11 56m. 3 7.0
POMGANGROVER: | kes cance foes 0) 0.0 0 0.0 0 0.0
Total... 24 100 1 30 100.0 43 909 9
Table 26.—Effect of ingested lead shot on migration of mallards, as measured by distances
traveled by dosed and by undosed birds before they were shot by hunters. The data are for
birds trapped and released at the Chautauqua National Wildlife Refuge in the fall months of
1951; 504 of the birds were dosed with one No. 6 shot pellet each, 504 were dosed with four
pellets each, and 507 were not dosed. Figures show for dosed and for undosed ducks the per
cent of recovered bands (those recovered in year of banding and for which distance data are
available) that were recovered at various distances from the point of banding and release.
Q PELLET 1] PELLET 4 PeLLets
Mies From PLace oF Number | Per Cent | Number | Per Cent | Number | Per Cent
BANDING of Bands | of Bands | of Bands | of Bands | of Bands | of Bands
Recovered | Recovered | Recovered | Recovered | Recovered | Recovered
in Period | in Period | in Period | in Period | in Period | in Period
OF50. 2... 5. 36 69.2 51 67.1 94 95.9
S1=TCOG Seer ome a 4 thea 7 O)e) 0 0.0
{1C0)1 551 0 Ea eee Sere a 0 0.0 1 iL 8) 1 1.0
20m oa! 2) 3.9 4 58 (0) 00
201-300..... 4 Hea 7 9.2 1 1.0
BO400 2. a... ces 6 11.5 4 BES 1 1.0
401 and over.... 0) 0.0 2 2.6 1 1.0
LLG] a ee Tene 52 100.0 76 100.0 98 99.9
274
become ill from lead poisoning have mi-
grated farther than 50 miles from where
they ingested shot.
Effect of Lead on Year-of-Banding
Mortality Rate
The mortality rates of the dosed and
the undosed mallards in the year of band-
ing or the first year (to end of following
August) after being banded and released
are indicated by data in table 27. Each
I_tinois NATURAL History SurvEY BULLETIN
Vol. 27, Art. 3
1950:8-12) as to have only a minor effect
upon the mortality rates.
Most of the year-of-banding mortality
rates for the undosed, or control, groups
in the experiment were lower than even
the lowest of the year-of-banding mortal-
ity rates for mallards reported by Bell-
rose & Chase (1950:8—-12). In the Bell-
rose & Chase study, a correction factor
was used for bandings made during the
hunting season, and mortality rates were
Table 27.—The year-of-banding mortality rates of wild, free-flying mallards undosed and
of similar mallards dosed with one, two, or four No. 6 lead shot pellets each. The data are for
mallards trapped, banded, and released at the Chautauqua National Wildlife Refuge near
Havana, Illinois. The mortality rates were derived as explained in the section entitled “Effect
of Lead on Year-of-ERanding Mortality Rate.”
“4 ies A Morva.ity Rate
wis a Banp RECOVERIES (Per Cent)
Spt PR way ee BanD RECOVERIES IN First 4 YEARS
wo |A}A!] S| ga] Year or Banvinc Arrer BANDING ue 80 Scetsu
° Zz fy 7] Q Q x» os 7 S < 92
ay = aoe ee ies) Esc 08
< Zz 4 ra] 5 (S) Ds vop,ouvs
mia a) o iq S32 ul J ee 6-50
S48 nm | a | a |zZQ | Number | Per Cent | Number | Per Cent al") ARAgY
1949....|M]} AJ] 0} 560 19 8139 143 25.53 1353 ee
M|A 1 1s559 35 6.26 155 2173 2286 9.3
1950....|M]}AJ| 0] 278 33 11.87 106 38.13 Sila cee
M|A Li}: 8274 45 16.42 103 3-9 43.7 1256
M|A 2 27 74 26.71 99 35.74 74.7 43.6
M | J Oct ah 17 15632 43 38 74 395 abet
M| J 1 117 15 12.82 35 29.91 42.9 3.4
M| J 2 SEES 21 18.26 49 42.61 42.9 34
19ST MRA 011-300 24 8.00 77 25.67 31 2 Beebe:
Mj; A Ls 24 42 12 96 91 28.09 46.2 15.0
M|A]| 4] 284 58 20.42 80 28.17 72.5 41.3
M | J Oer207 23 inert 13 3527 31.5 Shh Grea
M | J 1 180 24 13.33 66 36.67 36.4 4.9
M | J 4 | 220 41 18.64 65 29.55 63.1 31 6
1939-
1943i | F 0 17,897) 390 4.94 1,094 13 85 35.6) <| Soee eee
1951.7...) EF D501 87 fei 151 30.14 57.6 22.0
*M=male; F=female.
7 A=adult; J=juvenile.
tNo control hens were available at time of 1951 experiment; so recoveries for the first 4 years
from bandings
of hen mallards at the Chautauqua National Wildlife Refuge, 1939-1943, were used for the control data.
mortality rate was derived by comparing
the shrinkage in the population in the
year of banding (as measured by year-of-
banding band recoveries) to the popula-
tion at the time of banding (as measured
by the total band recoveries at the end of
the fourth year after banding). For ex-
ample, the mortality rate for adult un-
dosed males released in 1949 was found
by dividing 19 by 143, table 27. Al-
though not all mallards of a banded group
are dead by the end of the fourth year
after being banded, the proportion of the
group alive is so small (Bellrose & Chase
calculated from the corrected percentages,
rather than the numbers, of bands recoy-
ered.
In each year and in each sex and age
class for which data were collected, the
mallards dosed with lead shot had a higher
mortality rate during the year of banding
than the control, or undosed, mallards,
table 27.
For adult drake mallards dosed with
one shot pellet each, in 1949, 1950, and
1951, the year-of-banding mortality rates
were 9.3, 12.6, and 15.0 per cent, respec-
tively, greater than the mortality rates for
May, 1959
the controls. Adult drake mallards dosed
with two shot pellets each in 1950 had a
year-of-banding mortality rate that was
43.6 per cent greater than that of drakes of
the same age class used as controls in the
same year. Adult drakes dosed with four
pellets each in 1951 had a year-of-banding
mortality rate that was slightly, and unac-
countably, lower than that of birds of the
same sex and age class dosed with two pel-
lets each in 1950.
Juvenile drake mallards in 1950 and
1951 had lower year-of-banding mortality
BELLROSE: LEAD POISONING IN WATERFOWL
275
for the undosed hens banded and released
in 1939-1943.
At the Rocky Mountain Arsenal, near
Denver, Colorado, wild mallards were
banded, dosed with lead shot, and released
in late winter months, 1950 and 1951, by
Johnson A. Neff and Charles C. Sperry
of the U. S. Fish and Wildlife Service
and Irving R. Poley of the Colorado De-
partment of Game and Fish, table 28.
Band data for 1951 were not used _ be-
cause, as Neff (letter, February 5, 1955)
reported, a chemical pollution of the water
Table 28.—Number and per cent of bands recovered, 1950-1954, from mallards trapped,
banded, and released at the Rocky Mountain Arsenal, Denver, Colorado, February 13—March 21,
1950. Before release, half of the males and half of the females were dosed with six No. 6 shot
pellets each, and the others were released, undosed, to serve as controls.*
NuMBER OF NuMBER OF Per CENT OF
Sex SHor Dose Ducks Banps BANnpDs
BANDED RECOVERED RECOVERED
Male...... 0) 200 56 28.0
IMPAIE Se oe 6 200 19 9.5
[icranealtey aus aaah Oe eel ae atte 0 125 13 10.4
ienraleenkr ate te cea 6 125 12 9.6
*Experiments conducted by Johnson A. Neff and Charles C. Sperry of the U. S. Fish and Wildlife Service and
Irving R. Poley of the Colorado Department of Game and Fish.
rates than those of adult drakes dosed
with the same number of pellets each.
One group of juvenile drakes dosed with
one shot pellet each and another group
dosed with two shot pellets each in 1950
had year-of-banding mortality rates only
3.4 per cent greater than the rate for the
controls. Juvenile drakes dosed with four
pellets each in 1951 had a mortality rate
that was 31.6 per cent greater than that
of the juvenile controls but 9.4 per cent
less than that of adult drakes dosed with
the same number of pellets each in the
same year.
Because in 1951 no mallard hens were
banded and released to serve as controls
for 501 hens dosed in that year with one
shot pellet each, no comparison of band
recovery rates could be made between
dosed and undosed females released in the
same year. However, band recovery fig-
ures were available for 7,897 undosed
mallard hens banded and released in the
period 1939-1943. The year-of-banding
band recovery rate for the hens dosed,
banded, and released in 1951 was 22.0
per cent greater than the recovery rate
may have caused mortality which would
bias subsequent band recoveries.
Wild mallards were caught in the late
winter months of 1950 and divided into
two groups, each consisting of 200 drakes
and 125 hens that at the time of capture
were free of lead in their gizzards, as de-
termined from fluoroscopy. The ducks
were banded, those in one group were
dosed with six No. 6 lead shot pellets
each, and all were immediately released.
The difference in band recoveries between
the control and the dosed groups from the
1950 hunting season through the 1954
season provided an index to the magnitude
of mortality caused by the ingestion of six
No. 6 shot pellets per duck, table 28.
If there had been no mortality from
lead poisoning among the dosed mallards,
the number of band recoveries in the sub-
sequent hunting seasons would have been
similar for the dosed and the undosed
groups. The fact that there were almost
three times as many band recoveries in
subsequent hunting seasons from the un-
dosed drakes as from the dosed drakes,
table 28, suggests that the mortality ratio
276
between drakes that ingest six lead pellets
each and those that ingest no lead is ap-
proximately 3 to 1. The difference in
band recoveries between undosed and
dosed hens was so slight as to indicate lit-
tle mortality from lead poisoning.
An apparent reason for the large dif-
ference in the mortality rates between the
Colorado drakes and hens is that in late
winter and early spring hens are less sus-
ceptible than drakes to lead poisoning.
Illinois experiments made with captive
mallards under controlled conditions
showed that during the spring hens are
less susceptible to lead poisoning than are
drakes (Jordan & Bellrose 1951:21).
With the approach of the breeding season,
the consumption of food by captive hens
greatly increased until it exceeded that by
captive drakes. Apparently the greater
food consumption by hens during this par-
ticular period was the primary factor re-
sponsible for the greater survival rate of
the Colorado hens. Illinois data suggest
that, during the fall, hen mallards are
much more susceptible than drakes to lead
poisoning. The year-of-banding mortality
rate for wild, free-flying mallard hens
dosed with one No. 6 lead pellet each was
about one-fourth greater than the highest
year-of-banding mortality rate for mallard
drakes similarly dosed, table 27. Among
penned mallards, the mortality rate of
hens was approximately double the mor-
tality rate of drakes except in spring (Jor-
dan & Bellrose 1951:21).
As shown by differences in mortality
rates between dosed and undosed birds, at
each shot level tested juvenile drakes were
much less susceptible to lead poisoning
than were adult drakes, table 27. The
lower susceptibility of the juveniles was
more marked at the one- and two-shot
levels than at the four-shot level. The
greater food intake by juveniles seems to
account for their lower susceptibility (Jor-
dan & Bellrose 1951:20).
There is good evidence that the drake
class of the mallard population is com-
posed almost equally of adults and juve-
niles. The following mortality rates have
been calculated on the assumption that
the numbers of adults and juveniles are
equal and that the percentages on which
the rates are based (in farthest right
column of table 27) hold true throughout
Intino1is NAaTuRAL History SurvEY BULLETIN
Vol. 27, Art. 3
the populations: In mallard drakes, one
No. 6 shot pellet per bird produces an in-
crease in the mortality rate of about 9 per
cent (12.6 and 3.4, 15.0 and 4.9 aver-
aged ) ; two pellets about 23 per cent (43.6
and 3.4 averaged) ; four pellets about 36
per cent; and six pellets about 50 per cent.
Because of the smaller number of ex-
periments conducted with hens than with
drakes, it is more difficult to appraise
mortality from lead poisoning in the hens.
However, the available data suggest that,
among hens and drakes with identical in-
gested shot levels, hens probably suffer
twice as great a mortality as drakes in the
fall and a small fraction of the mortality
of drakes in late winter and spring.
PREVENTING LEAD
POISONING
When Green & Dowdell (1936) re-
ported on the apparent feasibility of a
lead-magnesium alloy shot for the preven-
tion of lead poisoning in waterfowl, con-
servationists anticipated the eventual de-
velopment of this or some other shot that
would prove to be nontoxic to waterfowl
and acceptable to hunters. However, no
shot (with the possible exception of iron
shot) has been developed which meets the
requirements of both nontoxicity to water-
fowl and present shooting standards.
A study of shot alloys by Jordan &
Bellrose (1950) at the Havana labora-
tory of the Illinois Natural History Sur-
vey did not substantiate the findings of
Green & Dowdell (1936:487-8) that
lead-magnesium shot, upon its disintegra-
tion in the gizzard of a duck, fig. 8, did
not cause lead poisoning. On the con-
trary, Jordan & Bellrose (1950:166~7)
found that lead-magnesium shot, in spite
of its disintegration in the gizzard, was
as toxic as commercial lead shot.
Two other types of lead alloy shot
tested by Jordan & Bellrose (1950:
165-7), lead-tin-phosphorus shot and
lead-calcium shot, were not less toxic than
commercial shot.
A proposal to coat commercial shot pel-
lets with a nylon plastic was investigated.
Theoretically, at Jeast, pellets so coated
would have a good opportunity to pass
out of the gizzard before the plastic was
abraded away and the lead exposed. It
May, 1959 BELLrosE: LEAD PoIsoNING IN WATERFOWL
201.
Z
Fig. 8—The breakup of three lead alloy shot pellets containing magnesium (2 per cent)
in the gizzard of a mallard; 4, 1 hour after ingestion; B, 24 hours after ingestion; C, 96 hours
after ingestion; D, 144 hours after ingestion. As shown in D, the gizzard has failed to expel
a large proportion of the lead particles. Despite its disintegration in the gizzard, the lead alloy
shot containing magnesium was as toxic as commercial lead shot.
278
Table 29.—Relative effectiveness of iron
ILtinois NATURAL History SURVEY BULLETIN
Vol. 27, Art. 3
shot and commercial lead shot as measured by
the per cent of sample (game-farm mallards) bagged with No. 4 and No. 6 shot fired from
12-gauge full-choke gun at each of four ranges, 1950 and 1951.
Iron SHOT Leap SHOT
R No. 4 No. 6 No. 4 No. 6
ANGE IN
YARDS
Number Per Number Per Number Per Number Per
in Cent in Cent in Cent in Cent
Sample | Bagged | Sample | Bagged | Sample | Bagged | Sample | Bagged
SSP At ae ere 6 100 6 100 10 100 10 100
AOE cers 20 90 20 90 20 100 20 90
SOR. 20 75 20 55 24 88 28 79
60.. 20 45 8 12 20 70 18 22
was found, through administering pellets
of nylon plastic to mallards at the Havana
laboratory, that this material was very re-
sistant to abrasion. However, efforts to
coat shot pellets with nylon plastic were
unsuccessful. Metallurgists of the Win-
chester-Western Cartridge Division of
the Olin Mathieson Chemical Corpora-
tion were unable to coat commercial lead
shot with nylon plastic because the spread
between the melting point of lead and the
congealing point of the nylon plastic was
too small.
Several metals generally regarded as
being nontoxic to waterfowl were consid-
ered as substitutes for lead. Domestic
availability, price, physical and mechani-
cal properties, and corrosion resistance
were the judgment criteria. Of all the
metals considered, iron was the only one
available in sufficient quantity and low
enough in price to warrant further inves-
tigation. From the standpoint of prop-
erties alone (excluding availability and
price), there are metals that would make
as good or even better shot pellets. Gold
is an extreme example. It is soft, non-
toxic, noncorrosive, and heavier than
lead. However, its price and lack of
availability immediately rule it out.
Pellets made from an iron alloy were
tested at the Illinois Natural History
Survey Havana laboratory for toxicity to
waterfowl. Penned wild mallards were
dosed, each with 10 No. 6 iron pellets.
The ducks showed no ill effects as a result
of the ingestion of iron.
The Winchester-Western Cartridge
Division expended considerable time and
effort in the development of a satisfactory
shot of iron alloy. Early difficulties in
making true spheres, excessive abrasion
Table 30.—Relative effectiveness of iron shot and commercial lead shot as measured by
the average number of No. 4 and No. 6 pellets that hit the trunks of game-farm mallards, and
the per cent of pellets hitting the trunks that penetrated to the trunk cavities, at each of four
ranges, 1950 and 1951. The shot was fired from a 12-gauge full-choke gun.
Iron SHOT Leap SHOT
No. 4 No. 6 No. 4 No. 6
ee Per Cent Per Cent Per Cent Per Cent
Yaris Average | of Trunk | Average | of Trunk | Average | of Trunk | Average | of Trunk
Number of|Hits Pene- |Number of} Hits Pene- |Number of| Hits Pene-|Number of} Hits Pene-
Trunk | trating to| Trunk trating to} Trunk trating to| Trunk | trating to
Hits Trunk Hits Trunk Hits Trunk Hits Trunk
Cavities Cavities Cavities Cavities
35). 8 3 60 16.2 43 6.6 65 11.6 47
40.. 6.8 39 11.8 27 Sie7, 68 8.8 41
50.. 39 21 4.9 17 322 59 Sy) 33
60. . 24 17 1.9 o ponds 48 3.4 18
May, 1959
of gun barrels, and range limitations were
for the most part overcome. A special
shooting process (Patent No. 2,544,678)
was developed. By repeated annealing in
furnaces with controlled atmospheres, the
iron alloy was substantially reduced in
hardness. Many thousands of shot shells
fired with iron shot loads showed that
soft iron had little, if any, adverse effect
on modern gun barrels and adjustable
chokes.
One of the principal disadvantages of
using iron shot for shot shell loads is that
its lower density reduces its effectiveness
at maximum ranges. In 1950 and 1951,
the relative killing power of iron shot and
of lead shot was investigated by shooting
game-farm mallards under controlled con-
ditions (Bellrose 1953:353-5).
No. 4 and No. 6 shot were used at
ranges of 35, 40, 50, and 60 yards, table
29. Iron shot and lead shot fired from a
12-gauge, full-choke gun showed no differ-
ence in killing power at 35 yards, but
iron shot declined in relative effectiveness
as the ranges increased.
At ranges of 35 and 40 yards, the num-
ber of pellets hitting the trunks of ducks
averaged higher for iron shot than for
lead shot, table 30. For comparable ranges
and shot sizes, the percentage of pellets
hitting the trunks that penetrated to the
body cavities was greater for lead shot.
The greater number of hits registered
on game-farm ducks by iron shot than by
lead shot at the short ranges can be ex-
plained by the larger load of iron pellets
in each shot shell. Because of the lower
density of iron, more iron pellets than
lead pellets of the same size can he loaded
in a shot shell having the same powder
charge. A standard 12-gauge duck load
contains about 169 No. 4 lead pellets;
such a load would contain about 250 iron
pellets. Because the impact potential of
shot at long range increases with increases
in size of shot, some compensation can be
made for the relative decline in killing
power of iron shot at long range by using
iron shot one size larger than that custo-
marily used in lead shot, that is, No. 4
instead of No. 5 in a given situation.
There are no insurmountable obstacles
to the use of iron shot for waterfowl hunt-
ing. The conclusion which Winchester-
Western drew from extensive research
BELLROSE: LEAD POISONING IN WATERFOWL 279
was that an iron shot acceptable for most
shot shell requirements could be produced.
However, the required manufacturing in-
vestment would be large, and this factor,
coupled with uncertainty concerning cus-
tomer acceptance, convinced W inchester-
Western that manufacture of iron shot
was not feasible unless drastic action was
needed to save waterfowl from serious
lead poisoning losses.
If drastic action should at any time be
necessary, the U. S. Fish and Wildlife
Service could require waterfowl hunters
to shoot only shells containing iron shot;
shells with such a load could be so marked
that inspection by conservation officers
would insure compliance with regulations.
DISCUSSION
The incidence of ingested lead shot in
the segment of a duck population har-
vested by waterfowlers is not representa-
tive of the entire population nor the en-
tire year. It is representative of only a
part of the population (the segment har-
vested) and a short period of time (the
time of sampling).
The percentage of ducks that have in-
gested shot at some time during the year,
or during the period in which most inges-
tion of shot occurs, may be calculated
through application of correction factors
that take into account (1) the fact that
ducks carrying lead are more vulnerable
to hunting than are lead-free ducks and
(2) the fact that most ducks ingesting lead
either void the lead or die of poisoning
within about 4+ weeks.
As shown by experiments in which
wild mallards were trapped, banded, and
released, some dosed with lead and others
not dosed, the birds dosed with one No. 6
shot pellet each were about 1.5 times
(1.19-1.84, table 20) as vulnerable to
hunting as were the controls; those dosed
with two pellets each were 1.89 times as
vulnerable as the controls; and_ those
dosed with four pellets each were 2.12
times as vulnerable. The incidence of
lead in an entire population at any one
time is therefore less than the incidence
of lead in the segment of the population
taken by hunters; for the populations dis-
cussed in this paper the incidence of lead
can be calculated by applying 1.5, 1.9, and
280 ItLtinois NaturAL History SurvEY BULLETIN
2.1 as correction factors at the one-, two-,
and four-pellet levels.
Application of the correction factor de-
signed to nullify hunting bias at the one-
pellet level indicates that during the hunt-
ing season an average of 2.96 per cent of
the mallards of North America are car-
rying one ingested lead pellet each, table
31. The application of correction factors
at other shot levels is shown in table 31.
The correction factors for three-, five-,
and six-plus-pellet levels were derived
through interpolation or extrapolation.
Daily during the fall and winter
months, some ducks in the North Ameri-
can population are ingesting shot pellets,
some are voiding them, some are dying
from their effects, and some are recover-
ing.
Unpublished Natural History Survey
reports of laboratory studies by James S.
Jordan show that penned wild mallards
that have ingested one or more No. 6 shot
pellets each may eliminate the pellets as
early as the first week after ingestion or
they may retain them as long as several
weeks, until the pellets have become thin
wafers 0.05 inch or less in diameter. The
appearance of lead pellets that have spent
various periods of time in the gizzards of
ducks is shown in fig. 9.
Vol. 27, Art. 3
The penned wild mallards that were
dosed by Jordan with one No. 6 shot pel-
let each and that showed few or no indi-
cations of lead poisoning had eliminated
the pellets by the thirty-first day. The
average period of lead retention by the
ducks in this category was 18 days. Mal-
lards that were dosed with two or with
four pellets each and that showed no sig-
nificant manifestation of lead poisoning
had eliminated the pellets about as rap-
idly as those dosed with one pellet each.
The penned mallards that were dosed
with one No. 6 shot pellet each and that
showed moderate to severe effects of lead
poisoning had eliminated no pellets in the
first week; at the end of 4 weeks, only 27
per cent of these ducks had voided all the
pellets with which they had been dosed.
Twenty-one per cent of 119 penned
mallards that had eliminated all shot pel-
lets they had been given (one to four
pellets each) died from lead poisoning. A
study of the history of these ducks led to
the conclusion that a large proportion of
the ducks that retain lead shot for 3 or
more weeks die from its effects.
As previously discussed, most mallards
in the wild that die from lead poiconinz
perish in the second or third week after
they have ingested lead. Most mallards
Table 31.—Estimated percentages of North American mallard population lost as a result
of lead poisoning. The figures for the various shot levels have been corrected for hunting bias
and population turnover.
the gizzard of a duck.)
(By shot level is meant the number of ingested shot pellets found in
SHOT SHOT Per Cent
HunrTING InciDENCE | INcIDENCE | MortTAtity OF
SHot LEVEL SHOT Bias CorreEcTED | CorRECTED RATE Popu-
Inci- CorreEc- FOR FOR (PERCENT)}{t| LATION
DENCE TION HuntTinc Turn- Lost§
Facrort Brast OVER**
[hoe 4.44 15 2.96 17.76 9 1.69
Dison. 1.14 1.9 0.60 3.60 23 0.83
Bye 0.47 2.08§ 0.24 1.44 308§ 0.43
4., 0.18 Dal 0.09 0.54 36 0.19
Ser 0.14 2.28§ 0.06 0.36 4388 0.15
Oat A hes wee 0.05 2.38§ 0:02 2 aor 508§ 0.06
Galen ce dea ae 0.38 2.48§ 0.16 0.96 7588 0.72
Total en 6.80 4.13 24.78 3.98
*From table 11.
+ From table 20, nearest 0.1.
{Derived as explained on pages 279 and 280 (at one-pellet level:
**Turnover correction factor 6, derived as explained on page 281.
++Derived as explained on page 276. These fgures are for mallard drakes of the Mississippi Flyway, but they
are applicable to the continental mallard population.
8Derived by multiplying mortality rate (per cent) by shot incidence corrected for turnover.
8§Derived by interpolation or extrapolation from available data.
4.44 & 1.5 = 2.96).
May, 1959
that ingest lead have either died or re-
covered within 4+ weeks.
Observations in the field and in the
laboratory indicate that a mallard that
survives ingestion of lead will have elim-
inated the lead 18 days, on the average,
after ingestion; a mallard that dies with
lead still in its gizzard will die 21 days,
on the average, after ingestion. Because
of these observations, 20 days have been
BELLROSE: LEAD PoIsonNING IN WATERFOWL 281
populations ingest lead shot. Malysheff
(1951), after making chemical analyses
for lead in the bones and livers of water-
fowl taken in the Lower Fraser Valley of
British Columbia, reported that 52.1 per
cent of the 79 mallards he examined had
at one time or another in their lives in-
gested lead; at the time of examination
only about 16 per cent of the mallards
had lead in their gizzards and about 36
Fig. 9—The appearance of No. 6 lead shot pellets that spent various periods of time in
the gizzards of ducks.
chosen as the average period of turnover
of leaded mallards in the wild.
As indicated by the presence of lead in
duck gizzards collected from hunters and
by lead poisoning die-offs, the lead poison-
ing “season”? (the period of greatest ex-
posure to lead deposited in feeding areas
from the guns of hunters) is a 120-day
period that begins with November and
ends with February. If, as believed, mal-
lard gizzards collected at any one time
are representative of only a 20-day turn-
over period, the number of mallards in-
gesting lead in the 120-day lead poison-
ing “season” is six times the average of
the numbers obtained from samples taken
in the “season.” ‘Then the factor to be
used in correcting for turnover is 6.
This correction factor applied to inci-
dence figures corrected for hunting bias
indicates that approximately one-fourth
of the wild mallards of North America in
any one year ingest lead shot, table 31.
There is evidence that a much larger
proportion than one-fourth of some duck
per cent had survived previous lead inges-
tion. Malysheff found that 38.2 per cent
of 35 pintails showed evidence of lead;
22.9 per cent had lead in their gizzards
at the time of examination, and approxi-
mately 15 per cent had survived previous
lead ingestion.
Mortality rates for Mississippi Flyway
mallards dosed with lead shot are pre-
sented in table 31; the figures have been
adjusted for survival differences between
adults and juveniles, as discussed on page
276. Figures for dosages of three, five,
six, and six-plus pellets have been derived
by interpolation or extrapolation.
If the lead poisoning mortality rates
for mallards in other parts of North
America are approximately the same as
in the Mississippi Flyway, then for the
entire North American mallard popula-
tion the annual loss due to lead poisoning
can be calculated, table 31. The figure
1.60 derived for the per cent of the mal-
lard population lost as a result of inges-
tion of one shot pellet per duck has greater
282
reliability than the other figures, as it is
based on a greater number of field data.
The calculations on which the figures
in table 31 are based have many shortcom-
ings. However, the figure 3.98 arrived
at as the percentage of the mallard popu-
lation lost as a result of ingestion of lead
shot is at least a ‘“‘calculated estimate.”
The figures in table 31 need qualifica-
tion and interpretation. They do not take
into account the number of mallards car-
rying lead that are harvested by hunters
and so are not wasted. Because ducks
carrying lead are more vulnerable to
hunting than are ducks that are free of
lead, table 20, a considerable proportion
of the mallards classified as lost in table
31 are bagged by hunters. The results of
twice-weekly surveys of public shooting
grounds in central Illinois during recent
hunting seasons indicate that the waste,
or unharvested loss, due to lead poisoning
is about one-fourth less than the 3.98 per
cent calculated as the total loss, or ap-
proximately 3 per cent.
The estimated 3 per cent waste due to
lead poisoning represents day-to-day, non-
catastrophic losses and does not include
such spectacular losses as those associated
with die-offs, in which large proportions
of localized populations fall victim to lead
poisoning. On the basis of data in table
1, it is estimated that, for mallards of the
Mississippi Flyway, to the 3 per cent
waste mentioned above should be added
1 per cent to cover the die-off losses, a
total of 4 per cent. For mallards of other
flyways, the die-off losses are markedly
less, table 1.
Mallards have made up the bulk of the
ducks found in important lead poisoning
die-offs in the United States in recent
years, table 1. This fact is construed to
mean that the mallard is more susceptible
to lead poisoning than other species of
waterfowl.
Most available evidence points to the
pintail as the species second to the mallard
in susceptibility to lead poisoning, table 1.
Malysheff (1951) found the pintail even
more susceptible than the mallard in
small samples taken in British Columbia.
Although, as table 11 indicates, in North
America as a whole a greater percentage
of pintails than of mallards ingested shot,
the influence of the more beneficial diet
ItLinors NarurAL History Survey BULLETIN
Vol. 27, Art. 3
of the pintail is evinced by the rela-
tively lower losses among ducks of this
species on areas where both pintail and
mallard have been involved in important
lead poisoning die-offs, table 1.
The extremely low shot _ incidence
found in the blue-winged teal, green-
winged teal, shoveler, and wood duck
precludes lead poisoning as a cause of ap-
preciable losses in these species. In addi-
tion to having a low rate of shot inges-
tion, the baldpate and the gadwall feed
largely upon leafy aquatic vegetation, food
highly beneficial in alleviating the effects
of ingested lead; mortality from lead poi-
soning is considered to be almost negli-
gible in these species.
Noticeable lead poisoning die-offs are
extremely rare in the redhead, ring-necked
duck, canvasback, and lesser scaup, table
1, even though these species have the high-
est incidence of ingested shot recorded
among waterfowl, table 11. It must be
concluded, therefore, that lead poisoning
is not an important mortality factor in
ducks of the genus Aythya. This fact
seems attributable to their beneficial diets.
In spite of a low rate of shot ingestion
by Canada, blue, and snow geese, table 11,
these species have become victims of lead
poisoning die-offs on a surprisingly large
number of occasions, table 1, but, in each
case, the per cent of the population lost has
been low. Inasmuch as these geese feed
primarily on corn in the areas where the
die-offs have occurred, diet appears as an
important factor contributing to their
mortality.
As mentioned above, approximately 4
per cent of the mallard population of the
Mississippi Flyway is wasted annually as
a result of lead poisoning. The annual
mallard waste in other flyways is esti-
mated to be between 3 and 4 per cent.
The annual waste due to lead poisoning
among all species of waterfowl in all
North American flyways is estimated to
be between 2 and 3 per cent of the popu-
lation.
Several students of waterfowl have
feared that in addition to direct losses due
to lead poisoning there are possible indi-
rect losses, such as lead-induced sterility.
Wetmore (1919:11) and Shillinger &
Cottam (1937:400) are among the au-
thors who have voiced concern over possi-
May, 1959
ble sterility. his concern has been fos-
tered by evidence that lead reduced the
virility of domestic poultry and acted as
an abortifacient in mammals.
In two laboratory studies which have
been made on the effect of ingested lead
on sterility in waterfowl, the conclusion
was reached that the lead had little per-
ceptible effect upon reproduction. Of the
first study, with game-farm mallards,
Cheatum & Benson (1945:29) stated
that: “These few data indicate that among
the mallard drakes used, those which re-
covered from lead poisoning did not ex-
hibit a significant loss of fertility.’ From
the second study, in 1948 and 1949, in
which both drake and hen game-farm mal-
lards were used, Elder (1954:322) con-
cluded that: “Leaded birds received 18
shot while on a grain diet, and the result-
ing toxemia was very severe. However,
normal birds did not exceed leaded birds
in fertility, embryonic success, or hatch-
ability. But in both years the normal hens
surpassed leaded hens in fecundity for the
season.”
Rarely do waterfowl in the wild ingest
as many as 18 shot pellets per duck, and
seldom do waterfowl in the wild recover
from toxemia as severe as that exhibited
by ducks in the 1949 experiments by
Elder.
At the present time, lead poisoning
losses in waterfowl do not appear to be
of sufficient magnitude to warrant such
drastic regulations as, for example, prohi-
bition of the use of lead shot in water-
fowl hunting. Should lead poisoning be-
come a serious menace to waterfowl pop-
ulations, iron shot provides a_ possible
means of overcoming it.
Although lead poisoning apparently
does not at the present time cause mor-
tality of such magnitude as to endanger
the North American waterfowl popula-
tion, it nevertheless poses an important
problem for the future. In the past, the
incidence of lead poisoning has increased
as numbers of waterfowl hunters have in-
creased. Because further increases in the
numbers of these hunters are expected,
the search for the best possible solution to
the lead poisoning problem should be con-
tinued.
From a compassionate as well as a man-
agement viewpoint, lead poisoning is a
BELLROSE: LEAD PoIsoNING IN WATERFOWL
283
problem that should concern every sports-
man. Birds that die from lead poisoning
suffer for 2 or 3 weeks preceding death.
SUMMARY
1. The mortality resulting from lead
poisoning in wild waterfowl has been a
cause of concern to conservationists for
many years.
2. A publicized die-off of ducks from
lead poisoning near Grafton, Illinois, in
January, 1948, brought the problem to
the attention of officials of the Western
Cartridge Company (now Winchester-
Western Cartridge Division of Olin
Mathieson Chemical Corporation) and
the Illinois Natural History Survey. This
resulted in a joint research project on
lead poisoning in waterfowl; research was
conducted largely at the field laboratory
of the Survey on the Chautauqua Na-
tional Wildlife Refuge, Havana.
3. The objects of the research project
were threefold: (1) evaluation of losses
from lead poisoning in wild waterfowl,
(2) investigation of lead alloys and other
materials for possible use as nontoxic shot,
and (3) determination of the physiologi-
cal effects of lead poisoning on waterfowl.
This paper is concerned primarily with an
evaluation of the losses from lead poison-
ing.
4+. The approach toward evaluating
the importance of lead poisoning involved
appraisal of (1) the incidence and mag-
nitude of waterfowl die-offs resulting
from lead poisoning, (2) the incidence
of ingested lead shot among waterfowl
populations in fall and early winter, and
(3) the extent of waterfowl losses result-
ing from the ingestion of various quanti-
ties of lead shot.
5. The history of lead poisoning in
North American waterfowl dates back to
the latter half of the nineteenth century.
Losses in the nineteenth century or early
twentieth century were reported from
Stephenson Lake and Lake Surprise,
Texas; Currituck Sound, North Caro-
lina; Puget Sound, Washington; Back
Bay, Virginia; and Hovey Lake, Indiana.
6. A survey conducted among state
and federal conservation agents and agen-
cies indicates that in recent years the
waterfowl losses from lead poisoning have
284 Ittino1s NaturRAL History SurvEY BULLETIN
been largest in the Mississippi Flyway
and have been followed in order by losses
in the Pacific, Central, and Atlantic fly-
ways.
7. In recent years, certain areas in the
United States have been the scenes of
several sizable die-offs of waterfowl af-
fected by lead poisoning. Among these
areas are Catahoula Lake, Louisiana;
Claypool Reservoir, Arkansas; Lake
Chautauqua National Wildlife Refuge,
Illinois; and Squaw Creek National
Wildlife Refuge, Missouri.
8. Most of the notable waterfowl die-
offs from lead poisoning have occurred in
late fall and early winter months, after
the close of the hunting seasons. Few
losses of ducks have been noted in the
spring, but losses of whistling swans and
of Canada, blue, and snow geese have
been reported at that time. There are no
recent records of waterfowl succumbing
from lead poisoning during the summer
months.
9. The mallard has been the principal
species involved in sizable lead poisoning
die-offs across the nation. The pintail has
predominated in losses recorded in the
Pacific Flyway. Where both species oc-
cur together in the Mississippi Flyway,
losses in the mallard have been relatively
higher.
10. In the Mississippi Flyway, 1938—
1955, 10.4 per cent of the mallard drakes
and 13.0 per cent of the mallard hens
picked up in die-offs carried no ingested
shot. In experiments with penned mal-
lards dosed with one to four No. 6 shot
pellets each, 21 per cent voided shot be-
fore death. ‘These figures suggest that
birds in the wild that succeed in voiding
shot are more likely to survive than are
penned birds that void shot.
11. Data from four widely separated
areas in which die-offs of mallards oc-
curred indicate that differences between
the areas in the numbers of ingested shot
pellets per drake resulted mainly from dif-
ferences in availability of shot and in diet
of ducks in the die-off areas.
12. The availability of lead shot pellets
to waterfowl on a particular body of
water is determined by (1) the shooting
intensity, or amount of shot on the bot-
tom, (2) the firmness of the bottom ma-
terial, (3) the size of the shot pellets in-
Vol. 27, Art. 3
volved, (4) the depth of water above the
bottom, and (5) ice cover.
13. The extent to which various spe-
cies of waterfowl are exposed to shot pel-
lets on the bottoms of marshes and lakes
is influenced by the feeding habits of the
birds and by the kinds of food ayvail-
able, as well as by the numbers of shot
pellets available.
14. The incidence of ingested shot pel-
lets in migrating waterfowl populations
was determined by (1) fluoroscopic ex-
amination of live-trapped ducks, (2) com-
pilation of data obtained from investi-
gators who had examined waterfowl giz-
zards for food content, and (3) fluoro-
scopic and direct examination of gizzards,
numbering many thousands, obtained
from ducks in hunters’ bags.
15. Fluoroscopy of trapped ducks
caught at baited traps on a heavily shot-
over area revealed that the birds had in-
gested abnormally large numbers of shot
pellets. Among three species, blue-winged
teal, wood duck, and pintail, feeding to-
gether, there appeared to be a relation
between the percentage of ducks ingest-
ing shot pellets and the size of individuals.
The species with the largest individuals
had the highest percentage of individuals
with ingested lead. In two of the species,
an appreciably greater percentage of juve-
niles than of adults carried ingested lead.
16. Fluoroscopy by wildlife techni-
cians on waterfowl breeding grounds dur-
ing the summer months revealed a low
incidence of ingested. shot among ducks
in Utah and Saskatchewan, but a high
incidence among those at the Delta
Marsh, Manitoba, which is one of the
most heavily shot-over areas in Canada.
17. Examination of 36,145 gizzards of
waterfowl bagged by hunters in North
America revealed many differences among
species in incidence of ingested lead. Less
than 1 per cent of the Canada geese and
less than 3 per cent of the blues and snows
had lead in their gizzards. Among the
ducks, the percentages carrying ingested
lead were as follows: less than 2 per cent
of the buffleheads, green-winged teals,
mergansers, wood ducks, shovelers, and
gadwalls; between 2 and 5 per cent of
the blue-winged teals, baldpates, and
common goldeneyes; between 5 and 10
per cent of the ruddy ducks, mallards,
May, 1959
black ducks, and pintails; more than 10
per cent of the canvasbacks, lesser scaups,
redheads, and ring-necked ducks.
18. A study of the feeding habits of
the various species of ducks in relation to
shot incidence indicated that grit prefer-
ences do not influence shot ingestion.
19. The incidence of ingested lead
shot was lowest among waterfowl of the
Central Flyway, higher among those of
the Atlantic, slightly higher still among
those of the Pacific, and highest among
those of the Mississippi Flyway. State
and local variations in shot incidence
within each flyway were numerous. The
incidence of ingested lead was more than
twice as high among ducks taken along
the Illinois River as among those taken
along the Mississippi.
20. Examination of live and hunter-
killed ducks indicated that much of the
lead ingested by waterfowl had been fired
from the guns of hunters in the season of
ingestion. Apparently, much of the shot
fired during a hunting season eventually
penetrated so deep into lake and marsh
bottoms that by the following summer it
was out of the reach of waterfowl.
21. Increases in the percentage of wa-
terfowl ingesting lead have paralleled in-
creases in the number of waterfowl hunt-
ers. Because there is expectation that the
number of duck hunters will continue to
increase, it can be anticipated that lead
poisoning will become more _ prevalent
among waterfowl than it is at present.
22. The magnitude of the shot level
(number of pellets in a gizzard) has an
important bearing on the rate of mortality
of waterfowl. Among 2,184 gizzards con-
taining lead shot, 64.7 per cent contained
only one pellet each, 14.9 per cent con-
tained two pellets each, and only 7.4 per
cent more than six pellets each.
23. A field experiment showed that
ducks afflicted with lead poisoning dur-
ing the hunting season are more likely to
be bagged than are healthy birds. Wild
mallards that were dosed with one No. 6
shot pellet each and released were 1.5
times as vulnerable to hunting as were
undosed controls; those dosed with two
shot pellets each were 1.9 times as vul-
nerable; and those dosed with four shot
pellets each were 2.1 times as vulnera-
ble.
BELLROSE: LEAD POISONING IN WATERFOWL
285
24. Among the dosed wild mallards,
the ingestion of lead shot pellets did not
appear to affect behavior until after the
first 5 days. Among birds dosed with one
shot pellet each, and that did not die of
lead poisoning, the period of affliction ap-
peared to persist for about 15 days;
among those dosed with two to four shot
pellets each, the period was longer.
25. The weakness and fatigue appar-
ent in dosed wild mallards that suffered
from lead poisoning reduced the ability
of the ducks to migrate. The larger the
number of ingested shot pellets per bird,
the greater was the reduction in move-
ment. Band recoveries from a group of
mallards dosed with four pellets each
showed that less than 5 per cent of the
birds migrated farther than 50 miles from
the banding station at which they were
dosed.
26. Among the dosed wild mallards in
1950 and 1951, at each dosage level the
mortality rate from lead poisoning was
higher for adult drakes than for juvenile
drakes. During the fall months, mortality
was higher among hens than among
drakes, but by late winter the situation
was reversed. Differences in mortality
rates among mallards of different ages and
sexes were attributed primarily to differ-
ences in the quality and quantity of food
consumed.
27. In a population of wild mallard
drakes, a population made up equally of
adults and juveniles, one No. 6 pellet per
bird is estimated to cause an increase in
mortality rate of about 9 per cent, two
pellets per bird an increase of about 23
per cent, four pellets per bird an increase
of about 36 per cent, and six pellets per
bird an increase of about 50 per cent.
28. An effort to find a lead alloy shot
pellet that was nontoxic to waterfowl was
unsuccessful. However, iron shot was
found to be nontoxic. Most of the diff-
culties us: manufacturing iron shot pellets
were overcome by technicians of the Win-
chester-Western Cartridge Division of
the Olin Mathieson Chemical Corpora-
tion. At present the principal disadvan-
tage in using iron shot pellets for water-
fowl hunting is that they are less effec-
tive at maximum ranges than are lead
pellets.
29. In determining the importance of
286
lead poisoning in a waterfowl! population,
it is necessary to eliminate the hunting
bias of samples and to ascertain the period
of turnover of migrating mallards that
are carrying lead in their gizzards.
30. Incidence figures corrected for
hunting bias and turnover suggest that
approximately one-fourth of the wild mal-
lards of North America in any year in-
gest lead shot.
31. It is estimated that, each year, ap-
proximately 4+ per cent of the mallards in
the Mississippi Flyway die in the wild as
a result of lead poisoning and that an ad-
ditional 1 per cent of the mallards in the
flyway are afflicted with lead poisoning
but are bagged by hunters.
32. For all waterfowl species in North
America, the annual loss due to lead poi-
soning is estimated to be between 2 and 3
per cent of the population.
ILLINoIs NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 3
33. Two studies made outside of IIli-
nois indicate that lead poisoning in water-
fowl does not seriously curtail the repro-
ductive capacity of ducks that recover
from the malady.
34. At the present time, lead poison-
ing losses do not appear to be of sufficient
magnitude to warrant such drastic regu-
lations as, for example, prohibition of the
use of lead shot in waterfowl hunting.
Should lead poisoning become a more se-
rious menace to waterfowl populations,
iron shot provides a possible means of
overcoming it. Because of the increasing
numbers of waterfowl hunters and the
increasing incidence of lead poisoning, as
well as because of the suffering that re-
sults among waterfowl seriously afflicted
with the malady, the search for the best
possible solution to the lead poisoning
problem should be continued.
LITERAT ORE -CATED
Ayars, James Sterling
1947. Lead on the loose. Sports Afield 118(6) :24—5, 92-4.
Bellrose, Frank C.
1947. Ducks and lead. II]. Cons. 12(1) : 10-1.
1951. Effects of ingested lead shot upon waterfowl populations. N. Am. Wildlife Conf.
Trans. 16:125-33.
1953. A preliminary evaluation of cripple losses in waterfowl. N. Am. Wildlife Conf.
Trans. 18: 337-60.
1955. A comparison of recoveries from reward and standard bands. Jour. Wildlife Mgt.
19(1):71-5.
Bellrose, Frank C., and Elizabeth Brown Chase
1950. Population losses in the mallard, black duck, and blue-winged teal. Ill. Nat. Hist.
Surv. Biol. Notes 22. 27 pp.
Bowles, J. H.
1908. Lead poisoning in ducks. Auk 25(3) : 312-3.
Cheatum, E. L., and Dirck Benson
1945. Effects of lead poisoning on reproduction of mallard drakes. Jour. Wildlife Met.
9(1) 26-9.
Cottam, Clarence
1939. Food habits of North American diving ducks. U.S. Dept. Ag. Tech. Bul. 643. 140 pp.
1949. Further needs in wildlife research. Jour. Wildlite Mgt. 13(4) : 333-41.
Elder, William H.
1950. Measurement of hunting pressure in waterfowl by means of X-ray. N. Am. Wildlife
Conf. Trans. 15:490-503.
1954. The effect of lead poisoning on the fertility and fecundity of domestic mallard ducks.
Jour. Wildlife Mgt. 18(3) : 315-23.
Green, R. G., and R. L. Dowdell
1936. The prevention of lead poisoning in waterfowl by the use of disintegrable lead shot.
N. Am. Wildlife Conf. Proc. 1:486-9.
Grinnell, George Bird
1894. Lead poisoning. Forest and Stream 42(6) : 117-8.
1901. American duck shooting. Forest and Stream Publishing Company, New York. 627 pp.
Hartmeister, Felix A., and Martin J. Hansen
1949. ‘The incidence of lead shot in three important Wisconsin waterfowl areas. Wis. Wild-
life Res. Quart. Prog. Reps. 8(3) :18-22.
Heuer, Wayne H.
1952. The incidence of lead shot in waterfowl of the Pacific Flyway, with special reference
to the Great Salt Lake Basin. Master’s thesis, Utah State Agricultural College, Logan.
49 pp.
Hough, E.
1894, Lead-poisoned ducks. Forest and Stream 42(6) : 117.
Hunt, George S., and Howard E. Ewing
1953. Industrial pollution and Michigan waterfowl. N. Am. Wildlife Conf. Trans.
18 :360-8.
Jones, John C.
1940. Food habits of the American coot with notes on distribution. U. S. Biol. Sury. Wildlife
Res. Bul. 2. 52 pp.
Jordan, James S., and Frank C. Bellrose
1950. Shot alloys and lead poisoning in waterfowl. N. Am. Wildlife Conf. Trans. 15:155-68.
1951. Lead poisoning in wild waterfowl. Ill. Nat. Hist. Surv. Biol. Notes 26. 27 pp.
McAtee, W. L.
1908. ‘Lead poisoning in ducks.’ Auk 25(4) : 472.
Malysheff, Andrew
1951. Lead poisoning of ducks in the Lower Fraser Valley of British Columbia: a chemical
study. Master’s thesis, University of British Columbia, Vancouver. 90 pp.
' Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson
1951. American wildlife and plants. McGraw-Hill Book Company, Inc., New York. 500 pp.
Martin, Dale N. ;
1957. Quarterly progress report, waterfowl investigation. Ind. Pittman-Robertson Wildlife
Res. Rep. 18(2) :112-7.
[ 287 |
288 ILLINOIS NATURAL History SuRVEY BULLETIN Vol. 27, Art. 3
Mohler, L.
1945. Lead poisoning of geese near Lincoln. Nebr. Bird Rev. 13(2) : 49-50.
Munro, J. A.
1925. Lead poisoning in trumpeter swans. Can. Field Nat. 39(7) : 160-2.
Phillips, John C., and Frederick C. Lincoln
1930. American waterfowl. Houghton Miffin Company, Boston and New York. 312 pp.
Pirnie, Miles David
1935. Michigan waterfowl management. Michigan Department of Conservation, Lansing.
328 pp.
Reid, Vincent H.
1948. Lead shot in Minnesota waterfowl. Jour. Wildlife Mgt. 12(2) : 123-7.
Shillinger, J. E., and Clarence C. Cottam
1937. The importance of lead poisoning in waterfowl. N. Am. Wildlife Conf. Trans.
2 398-403. :
Stall, J. B., and S. W. Melsted
1951. The silting of Lake Chautauqua. Ill. Water Surv. Rep. Invest. 8. 15 pp.
Suter, Max
1948. Temperature and turbidity of some river waters in Illinois. Ill. Water Surv. [Rep.
Invest. 1]. 14 pp.
Tener, John G.
1948. An investigation of some of the members of the sub-family Anatinae in the Lower
Fraser Valley cf British Columbia. Master’s thesis, University of British Columbia,
Vancouver. 66 pp.
Van Tyne, Josselyn
1929. The greater scaup affected by lead poisoning. Auk 46(1) : 103-4.
Wetmore, Alexander
1919. Lead poisoning in waterfowl. U.S. Dept. Ag. Bul. 793. 12 pp.
Yancey, Richard K.
1953. Lead poisoning on Catahoula Lake. La. Cons. 5(5) :2-5.
\'
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ILLINOIS NATURAL HISTORY SURVEY
Bulle tin Printed by Authority of he 2.
the State of Illinois We Ge
Food Habits
of Migratory Ducks
in Illinois
HARRY G. ANDERSON
‘TATE OF ILLINOIS ®& Wuuiaom G. Stratton, Governor
JEPARTMENT OF REGISTRATION AND EDUCATION ©® Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION ® Hartow B. Mitts, Chie}
a ati! ee ta, NATURAL
A 4 °
eee ee +
= ~ i. a
]
. ’
1
¥
BeLINOIS NATURAL HISTORY SURVEY
Bulletin =
Volume 27, Article 4 cs
2 ig ; Printed by Authority of
August, 1959 the State of Illinois
Food Habits
of Migratory Ducks
in Illinois
moeiek YG. ANDERSON
STATE OF ILLINOIS ® WiiaM G. Stratton, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION ©® Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION ® Hartow B. MiLts, Chief
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Sve E. Warkxins, Technical Assistant
H. B. Perry, Ph.D., Extension Specialist in Entomology*
Srevenson Moore, III, Ph.D., Extension Specialist in
Entomology*
Zenas B. Noon, Jr., M.S., Research Assistant*
Crarence E. Wuire, B.S., Research Assistant*
Joun Artuur Lowe, M.S., Research Assistant*
J. Davi Horrman, B.S., Research Assistant*
Cantos A. Wuire, B.S., Research Assistant*
Roy E. McLaucuuin, B.S., Research Assistant*
Costas Kousxorexas, M.S., Research Assistant*
Louise Zincrone, B.S., Research Assistant*
Mary E. Mann, R.N., Research Assistant*
Section of Faunistic Surveys and Insect Identification
H. H. Ross, Ph.D., Systematic Entomologist and Head
Mitton W. Sanverson, Ph.D., Taxonomist
Lewis J. Stannarp, Jr., Ph.D., Associate Taxonomist
Poitier W. Smitu, Ph.D., Associate Taxonomist
Leonora K. Groyp, M.S., Assistant Taxonomist
H. B. Cunnincuam, M.S., Assistant Taxonomist
Epwarp L, Mocxrorp, M.S., Technical Assistant
Tuerma H. Overstreet, Technical Assistant
Section of Aquatic Biology
Grorce W. Bennett, Ph.D., Aquatic Biologist and Head
Wiruiam C. Starrett, Pli.D., Aquatic Biologist
R. W. Larimore, Ph.D., Aquatic Biologist
Davio H. Bucx, Ph.D., Associate Aquatic Biologist
Rosert C. Hirtisran, Ph.D., Associate Biochemist
Donatpv F. Hansen, Ph.D., Assistant Aquatic Biologist
Wiruiam F. Cuivvers, M.S., Assistant Aquatic Biologist
Marirran Martin, Technical Assistant
Joun C. Crarrey, B.S., Field Assistant
Section of Aquatic Biology—continued
Ricnarp E. Bass, Field Assistant
Rosert D. Crompton, Field Assistant
Arnotp W. Fritz, B.S., Field Assistant*
Daviw J. McGinty, Field Assistant®
Section of Applied Botany and Plant Pathology
J. Cepric Canter, Ph.D., Plant Pathologist and Head
J. L. Forsperc, Ph.D., Plant Pathologist
G. H. Boewe, M.S., Associate Botanist
Ropertr A. Evers, Ph.D., Associate Botanist
Rosert Dan Neety, Ph.D., Associate Plant Pathologist
FE. B. Himecicx, Ph.D., Associate Plant Pathologist
Water Harrtstirn, Ph.D., Assistant Plant Pathologist
D. F. Scnoreneweiss, Ph.D., Assistant Plant Pathologist
Rovenia F. Firz-Gerarp, B.A., Technical Assistant
Section of Wildlife Research
Tuomas G. Scort, Ph.D., Game Specialist and Head
Ratex FE, Yeatrrer, Ph.D., Game Specialist
Cart O. Mour, Ph.D., Game Specialist
F. C. Betirosz, B.S., Game Specialist
H. C. Hanson, Ph.D., Associate Game Specialist
Ricuarp R. Graser, Ph.D., Associate Wildlife Specialist
Ronatp F, Lasisxy, M.S., Assistant Wildlife Specialist
Frances D. Rossins, B.A., Technical Assistant
Howarp Crum, Jr., Field Assistant
Joun L. Rosesperry, B.S., Technical Assistant
Rexrorp D. Lorp, D.Sc., Project Leader*
Frepericxk Greevey, Ph.D., Project Leader*
Guien C. Sanperson, M.A., Project Leader*
Jacx A. Ennis, M.S., Assistant Project Leader*
Tuomas R. B. Barr, M.V.Sc., M.R.C.V.S., Research
Assistant*
Bossie Joe Verts, M.S., Field Mammalogist*
Erwin W. Pearson, M.S., Field Mammalogist*
Keito P. Daupuin, Assistant Laboratory Attendant*
Gary P. Ime, Assistant Laboratory Attendant*
Section of Publications and Public Relations
James S. Ayvars, B.S., Technical Editor and Head
Biancue P. Younc, B.A., Assistant Technical Editor
Diana R. Braverman, B.A., Assistant Technical Editor
Wirtiam E. Crarx, Assistant Technical Photographer
Marcuerite VERLEY, Technical Assistant
Technical Library
Rutn R. Warrick, B
Nett Mires, MS.,
Librarian
S., B.S.L.S., Technical Librarian
B.S.L.S., Assistant Technical
CONSULTANTS: Herretorocy, Hosartr M. Smirn, Ph.D., Professor of Zoology, University of Illinois; Panasito.ocy,
Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and
of Veterinary Research, University of Illinois;
Wu pure Researcn, Wittarp D. Kuimsrra, Ph.D., Assistant Professor of Zoology and Director of Co-operative
Wildlife Research, Southern Illinois University
*Employed on co-operative projects with one of several agencies: University of Illinois, Illinois Agricultural
Extension Service, Illinois Department of Conservation, United States Army Surgeon General's Office, United States
Department of Agriculture, United States Fish and Wildlife Service, United States Public Health Service, and others.
This paper is a con’ribution from the Section of Wildlife Research.
os <= cal
(98485—5M—7-59)
CONTENTS
IP SEMPEB ERSTE NTIS PO aed irc Oe 8 cas Tike ee han Ski Sh ahh Pa AR RR 0 Pies pe 289
7, EEIRCR FESCUE eeedine SIS i na eget Ane A ee At ee SR Pine, Soe ae 290
EP GS ARCNUUIS gS) S220) 11S 2 aR Oy EU AS 5 292
pe LcaaN aS ice Heat MIN St ene LIES Arua oA eedag woereivenilan'E aph cisvahdl Re Huw nettle his ats ate 293
oT ERED VDA i TRIS Pe SAD Oe ee A A TSP ee 297
DS IIPE CIR EAE cs RUE ante eek: woo ce Rvs chads BAe Eee OEAIEO 301
2 FSGS ATT e759) B31 RSE Rey ee 2 IER Fe a Pera eee er ome rary 303
2 EERE ICER Laon ee IED Uae a se oe PC ee PRC a k= 307
eMTaRCEI GDA eee Neca Pee Ne ER eke Oy ho see ery ee eee 308
SUSVDRUTSILERRY | APR fo SN econ ea sr ge A Pe ER teers ORCA 310
SN MTRTERNSA IRE CS ENN ee a Rs occa ie BUM as eine IS EIS Cv SUPA oa ba cL 312
[ibyele, 1D vvelen a sted hn ol ed cane tae ree ge fee AE Me Rae ern ae SON NN STAR or od 314
| RES Eig: STS ZR gee Mice teal tale en Ie ie Sogn Cr le a ne RR ce ie ACE 315
MR Re ete nies Pee PELE ert Grnidhyst ee ale \ciaew teas nsa in gag os DERI Roe aR be coe S17
CBVERIDS ONG, S Aor TaN RAO Va aE eae | (KOS Se Re RE een er open wen eet 4 320
PMECLILECLCIMESE RT Ne Terre ee ede cst te ee geen SAN uratccdie cot a (ey atta) cuore Sy os RAL Rens Be ncic eac nae 321
EUs LEC RE sean San As pe ad ec ED acer Mara One Jeg 322
aU TATIRTO) METIS VE) iS ts, 8/02. sla oe ya, Ul 4 oa. 9 ein wc are tds wie 0 Sem ae ape aero 323
ES ean ATTEN Tee ce NOY aie oS i acces wand ares RUMEETE ee HERE A eR 323
LS TI as UES, OE Sa ae re en eA I RD oe 323
SERENE MDE PIE rt RED Pa WIC are aie ASSIA Goi dls eee eck 8 Soo oa Ste Sere ie Sats SEM alate pees 323
CLOSETS SB. yy PS Pe es aR RS eae ea A ee CUP ort eee 827
(hE CSS Oe AA She Pane ee ee en Mcrae wd ee 328
IRM NINIENGI TCT ns ce I as odio ox os tio 0. a SIMI SERN Saad Me rea iece I eoreae 329
JOLIN SIS Soe) SMG i a a op en a ange An Pe Opa Prie-on SER SRA er” 330
RU NNRr eR er a iy Be Stes he kG. 5, cletninpar ela ra eowia lew boo ehereee in ERAS aOR 330
trie UR reTMME OECD EU Seeks Ae PAG estonia s Be G Heme ea ena pad sae ye ah enaheuetenoNne te 331
PREC MIC OOLE TM NICE CriGASS ees Seis. coc ine Peirsol cud Mlacebhac ott Qh cL meth ch tens Rede A ener B52
OD. PE TEST SV PN a aR 8 x 2 ea fee i a UA A aye Aen SOL ca Seat 332
AME MITTS MINSTER GUO CEC Were olay AI fa aT Sanat ol wlohe asbws sv < Goat al sae Oa alals: win Ree 335
ukEOnDUSHe se. ee oe BN ne CaS EG SOA SS De ok pad tO ot ret Er tp at te 334
eee SPECIE Ce STITA LEWC ECS ec uae, ico ote as. Hates Se Coinuae a ieveonsios ater olcatvara helt ake <are aha 334
BNW MGT Sc meget ee eee Got el e eed h rasa, era agi oy Ox nate Veen ee 334
CUMPA cy ce COE Aa TeeA a a, TSE ay a UA SY A SO Rite a es Sei AE A ARB ome ae ORE S85)
a leer e ts PTS oa 2 ae hiker ae GE ped hc aN et eet Res ae CE ae AM gt RN LC a ht 335
~ EBay EC Hs Distr REE ah oo eR gra poi ari ice Rene Reaper ac Ae ee 336
ULES TEST RS See ORR ae aC ga SNE EE ore A et ee Re EE th 336
oan P SG Tis tne SO eet PR as Mn a Re Ae Ge A 337
“Pine UGE sn Ra to ee cree oae hs Le OGG) Te Mba ew a eee ee oct oe ee er eee eer 337
Bearer mPEN ENT = Sch hry en ec Poe sR AE ae come rd ielee ad = bea reais eee 337
SME PL CNTATNS Fee Cis 12 a aro vel SPOS ow eG ad es Sis e: 6 in Ly Se ate eros 337
VE ieal aisyeeay, = Bias SN et sean ae ies Ra Co J EO Re ee a ce RPG, OO Ga een AE 339
RES RS ha Rigo crich Sate ate coon Catena, or anes eee, SALES eal SATE Te eee 340
NTE We Py Cre ra AS datas ts ean Ne UC on Se TSR Baie phan ha LOR ie Slee a 340
BRET A CLE Fea NNN het afist 6) sulted deel cus ta nadine, clea eh noah Me ee och SRO ams aN Deaton 340
RUN TENLML NE STMMPEE Le rane SPE ccd cheney: cane sis te: diniei oad Coe InRO asia ta ard aloe ahaa Gttovehe dias TA 340
CNITEUCEL AVE UYAIEIS, 38 RE Etre REA EMESIS, LE EPR tet neotle, NiyActe ee A A egy) OTN ie teem DENS 1 Bs 340
Bee AC CM NS Sak Bed, tC a, Sec tead ee AIE a ele Peis sa aR ae oe Le ene 340
(ES AW eR MIR ON Zager US Sie et ee eT ee ee 340
ERM NEMEMDS ET eS el nd Se rey Sutin cr PR Reo eee AEE fig EE. bi sib Plas Sie wee werd Oo eieae a 342
une MR eet eth Tam pretty he a eismitamtene MALE Bie ais\ bem wislenu. 2 oi go) Boece nice 343
| TTR ores (CHa OT yk Soe Ty Bae Re a ee API AA ee Tey ae re ee te 344
on
s wr hal. Pa
rai o> i ee
aga ‘sa ce ha ake ed
ol sak ,
7
2.
-~
7 - ~
POMS SS
Aerial view of property belonging to a duck hunting club in the Illinois River valley. The
buildings are surrounded by water, uncultivated bottomland, and cropland. Material for the
duck food study reported here was obtained from this club and many others like it along the
Illinois and Mississippi rivers.
Food Habits of Migratory Ducks in Illinois *
, \WENTY-FIVE years ago the wa-
terfowl population of North Amer-
ica had dropped to such a low point
that management of this resource became
an important concern of both state and
federal wildlife agencies. As a basis for an
effective, long-time program of manage-
ment for the waterfowl of the Mississippi
Flyway, detailed information about the
diet of ducks that migrate through Illinois
was considered essential.
More than 30 years of drainage, silta-
tion, and pollution had materially reduced
the extent and quality of the Illinois feed-
ing grounds that waterfowl had used for
centuries. Fortunately for some species of
ducks, in the 1930’s, mechanical corn pick-
ers came into widespread use in the state.
Mechanical picking left more waste corn
in the fields and made it more easily avail-
able than did picking by hand. Mallards
and black ducks were quick to take advan-
tage of the new food supply.
Previous to 1938, only a small amount
of research had been done on the food
habits of ducks using Illinois as a stopover
on their migration flights. An analysis of
the contents of 185 duck gizzards collected
in Illinois had been made by Martin &
Uhler (1939:5), and a study of the con-
tents of 79 duck gizzards collected from
the Starved Rock Pool near Ottawa and
the Duck Island area near Banner, IlIli-
nois, had been made by Bellrose (1938).
The need for more data on the food habits
of waterfowl in Illinois resulted in the in-
vestigation herein reported.
Formally designated as Project 2-R,
“Correlation of Food Supplies With Food
Uses Among Illinois Game Birds,” the
investigation was a unit in the program
made possible by the Federal Aid in Wild-
life Restoration Act and was approved in
May, 1939, by the Bureau of Biological
*Federal Aid Project 2-R. Supervision of this project
was assigned by the Illinois Department of Conservation
to the Illinois Natural History Survey.
tLeader, Federal Aid Project 2-R, June 1, 1939-June
30, 1941: now employed by the United States Fish and
Wildlife Service.
HA RR Y2oG, ADD ERS Ont
Survey of the United States Department
of Agriculture (now Fish and Wildlife
Service of the United States Department
of the Interior). The project was off-
cially begun on June 1, 1939, and ter-
minated on June 30, 1941. Part of the
material and information on which the in-
vestigation was based was collected in
1938. Some of the data derived from the
project have been included in previous pub-
lications (Hawkins, Bellrose, & Anderson
1939; Bellrose & Anderson 1940, 1943;
Bellrose 1941, 1959). Delay in publica-
tion of the final report on the project re-
sulted largely from the author’s service in
the armed forces during World War II
and subsequent employment elsewhere.
Supervision of Project 2-R was assigned
to the Illinois Natural History Survey by
the Illinois Department of Conservation.
The project was administered by the late
Dr. Theodore H. Frison, representing the
Natural History Survey, and Anton J.
‘Tomasek, representing the Department of
Conservation. Dr. Lee E. Yeager, Arthur
S. Hawkins, and Frank C. Bellrose pro-
vided technical supervision; all three were
members of the Natural History Survey
staff at the time of the investigation.
ACKNOWLEDGMENTS
The writer of this paper gratefully ac-
knowledges the assistance of many per-
sons. He extends his thanks to personnel
of the United States Bureau of Biological
Survey, later the Fish and Wildlife
Service, for permitting use of the Patuxent
Research Laboratory and for giving in-
struction in food habits studies during the
early stages of this project, especially Dr.
Alec Martin for his many helpful sugges-
tions and his encouragement. He expresses
his appreciation to many present and for-
mer members of the staff of the [lIlinois
Natural History Survey, especially Dr.
Herbert H. Ross, Dr. Carl O. Mohr, and
Dr. B. D. Burks for their aid in identify-
ing insects; the late Dr. Leo R. Tehon for
[ 289 ]
290
his aid in identifying seeds ; William Mar-
quardt, Robert Welk, and William Rob-
ertson for their statistical assistance; Dr.
Harlow B. Mills and Dr. Thomas G.
Scott for their many helpful suggestions ;
and Frank C. Bellrose and James S. Ayars
for their assistance in the writing and edit-
ing of this report.
Finally, the author extends his thanks
to a great many individual hunters and
duck clubs for whole-hearted co-operation
in the field investigations and in the pres-
ervation of material.
STUDY PROCEDURE
Two general steps were involved in the
study procedure: (1) the collection of
duck gizzards from strategic locations
along the Illinois River and the Missis-
sippi River and (2) the laboratory an-
alysis of collected material.
The limited duration of this investiga-
tion made it desirable to choose collection
sites that would yield a large quantity of
gizzards within the short time of three
hunting seasons and that would provide
representative samples of the important
duck species using the major river valleys
in Illinois, frontispiece. “—wenty-one sites
were selected along the Illinois River be-
tween Ottawa and Florence, Illinois, and
11 sites were selected along the Mississippi
River between Rock Island and Quincy,
Illinois, fig. 1. Gizzards were obtained
during the hunting seasons of 1938, 1939,
and 1940 by Arthur S. Hawkins and
Frank C. Bellrose of the Illinois Natural
History Survey and the author.
Arrangements were made for collecting
the gizzards of ducks taken by members of
duck hunting clubs, by individual hunters,
and others. At most hunting clubs, mem-
bers had their ducks dressed as_ they
brought the birds in from marshes or lakes,
fig. 2; the clubs were a source of large
numbers of gizzards. Individual or free-
lance hunters often hired local profes-
sional duck pickers to clean their kills;
these pickers were another source of giz-
zards.
Co-operators were supplied with jars
partially filled with a 10 per cent formal-
dehyde solution; each jar bore a printed
label denoting a species of duck. Duck
pickers were instructed to drop each giz-
I_ttinois NarurAL History SurvEY BULLETIN
Vol. 27, Art. 4
zard into an appropriate jar. Gizzards
were collected from the co-operators once
each week and stored until such time as
their contents could be analyzed.
During the three fall hunting periods
of 1938-1940, 4,977 gizzards were col-
lected, table 1; 90.52 per cent (4,505) of
the gizzards came from locations along the
Illinois River and 9.48 per cent (472)
ROCK ISLAND
FLORENCE
Fig. 1—Map showing the areas from which
duck gizzards were collected in the autumns
of 1938, 1939, and 1940 between Ottawa and
Florence on the Illinois River and between
Rock Island and Quincy on the Mississippi
River.
came from collecting sites along the Mis-
sissippi River. The sample from the IlIli-
nois River valley represented 1.6 per cent
of the 1938 kill estimated for that region,
2.2 per cent of the 1939 kill, and 0.5 per
cent of the 1940 kill. A breakdown of the
number of gizzards obtained from 17 spe-
cies of ducks is given in table 1 by year
and river system. The species are listed
August, 1959
ANDERSO
N: Foop Hasirs oF Micratory Ducks
291
Fig. 2.—Picking ducks at a hunting club in the Illinois River valley. Duck gizzards collected
from this and similar clubs provided most of the material on which the present study is based.
As ducks were dressed, each gizzard was placed in a jar containing a formaldehyde solution
and bearing a printed label that denoted the duck species represented.
representing 17 species of ducks were collected.
Nearly 5,000 gizzards
Table 1—Number of waterfowl gizzards collected in Illinois, 1938-1940, at stations along
the Illinois and Mississippi rivers.
1938 1939 1940
|
‘ ae Tora
pagugee OER ILLINOIS ees ILLINoIs Bees. ILLINoIs Bre aes
RIVER RIvER RIvER RIVER RIvER RIVER
Common mallard*. 822 38 1,289 42 428 206 2,825
American pintail. . 268 9 467 115 22 881
Lesser scaup...... 73 53 66 eye Pete 28 220
Blue-winged teal. . | oy 6 63 1 1 | 129
Green-winged teal 199 2 164 3 25 393
Baldpate. 87 1 61 4 7 160
Ring-necked duck. 97 7 16 wee ee 120
Gadwall.. | 26 3 59 6 4 98
Canvasback....... | 14 4 9 | ae 28
Shoveler.. 25 2 34 foe 1 62
Ruddy duck. . oH ae 1 4 en 5
Wood duck....... 6 3 4 9 4 26
Walackaduckeet sors | chads nore nk 10 1 11
Redhead. . . 12 2) 14
Common goldeneye 2 1 Br 3
Greater scaup..... 1 1
Wlascuiawe-cencae a |) is sae Ste Rn © OMA ore ee Se 1 soll 1
Woighie 1,688 131 2243 43 574 208 4,977
*An unknown, but probably small,
common mallard. Some hunters did not distinguish between these two species.
number of gizzards of the black duck may
in the black duck category were from birds identified by the author.
be included with gizzards of the
Gizzards from individuals listed here
292
in descending order of the estimated num-
bers of individuals in the fall flight.
The procedure in making analyses of
the gizzard contents was in accordance
with standard practices followed by the
United States Bureau of Biological Sur-
vey (now United States Fish and Wild-
life Service) for food habits studies (Cot-
tam 1936:9-10). The contents were sep-
arated first into organic and inorganic sub-
stances and the volume of each expressed
as a percentage of the total volume. The
organic foods were then separated into
plant and animal foods and the volume of
each group expressed as a percentage of
the total organic volume. As an example,
the contents of a mallard gizzard were 8
cc. (80 per cent) organic material and 2
cc. (20 per cent) inorganic material. Of
the total organic foods, 6 cc. (75 per cent)
consisted of plant foods and 2 cc. (25 per
cent) of animal foods.
Inorganic material was found in the
gizzards in small to large amounts and
Intrnois NaATuRAL History SurvEY BULLETIN
Vol. 27, Art. 4
consisted primarily of sand, gravel, and
calcareous shell material. Individual par-
ticles were classified as to size in milli-
meters as well as to type and volume.
An effort was made to identify each
item in the organic contents, even though
it constituted only a trace or a fraction of
1 per cent of the volume, tables 38 and 39.
The technical names of most identifiable
plant items listed in table 38 were taken
from Gray's Manual of Botany (Fernald
1950). The technical names of animal
items listed in table 39 were taken from
several authorities and depended upon the
groups of animals involved. Seeds of some
of the duck food plants discussed in this
report are shown in fig. 3.
FOODS OF VARIOUS SPECIES
Data obtained from this study provided
important facts about food preferences of
each of the species of ducks represented.
The proportions of plant and animal foods
Fig. 3.—Seeds included in the autumn diet of ducks migrating through Illinois: (top row,
left to right) giant bur-reed, pickerelweed, American lotus, buttonbush, longleaf pondweed;
(second row, left to right) nodding smartweed, large-seeded smartweed, swamp smartweed,
marsh smartweed, chufa; (third row, left to right) Walter’s millet, Japanese millet, wild
millet, rice cutgrass, water-hemp; (bottom row, left to right) duck-potato, lophotocarpus, Ameri-
can bulrush, soft-stem bulrush, sago pondweed.
293
Ducks
ANDERSON
August, 1959
_— — wa Wh
SLESLEESEL BSS
pitce ce a cae eS =
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380 6 & 3)
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ee 5
et SgR eB key 5838
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& ces *ROsa gH
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a. metic aeh se se Cred ache Heine
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S| 2c Boo Reese Ss
Me = 8 if as) AU ay Ree aS!
e Sf S@eseloau &
iS) = 0°74 8 Sie aces
eS == Dee ire 5 =
<= 1S oOo v 79)
+ = Bye eS n =
Ce ae Sy SV) Si re, a! ey Sal site
See Satie SC SS woe we
Se} EN SEE TAR, eerie Goh
Pete aes of row, UNS
Ce pa Nn ;
mos eS eoU gy s 25,5
<3 os 3 Ge) - yn
= 4 set eS) (Sle Geel oh oN)
=e ae oe ee mS
Nc PO Feo) Cees
N a ISAS Nash aers el!
Shines Hg te er bate oc ei ace
v x CPN eae = ts
o 4 (3) Cool ey
a8 Oy esy te! ey os Ce ee
= on ty —
Gis Sy oe) te) Sy >|
_ aA Ow WY Ne Se onl
= z :
2 WWW 220 22979
nd of animal ma
&
SS
Cnn AAAS SSS Jivdaiva
ntages of plan
PLANTS
SCC w0}) 01 'Eu”[1>w>]9]079ys -
SANNA ES
Lad. DINVSYO. SSOUD JO LNSD dad
a e
umns of 1938, 1939, and 1940. Each of the most important
ely.
294
Ittinois NaturaL History SurveY BULLETIN
Vol. 27, Art. 4
Table 2.—Mallard gizzards collected in Illinois in approximately 2-week periods, 1938-1940.
YEAR
OcroBeR .
16-31
POSE el cer itsr es 282
1 AES Uae RP Se ae eo 389
112 FD ESR Sneek Si Coat 149
Lota iat ee 20
NoveMBER
1-15
272
325
120
717
NumBer OF GizzARDS
NoveMBER
16-30
306
396
258
960
DECEMBER
1-15
107
314
*Fourteen gizzards could not be dated to bimonthly periods;
ever, they are included in tables 3 an
hence, they are not included in this total.
Tora.
How-
Table 3.—The most important plant foods identified in 2,825 mallard gizzards collected
in Illinois, 1938-1940.
PLANT
PORAL PLAN Ee ee i. oe Ma ahs ole eae eee
Zea mays,corn ......
Leersia oryzoides, rice cutgrass.
Ceratophyllum demersum, coontail. .
Polygonum
coccineum, marsh smartweed. .
pensylvanicum, large-seeded smartweed...........
lapathifolium, nodding smartweed.
hydropiperotdes, mild \ water-pepper. . Garin
punctatum, dotted smartweed.................--
persicaria, \ady’s thumb..
hydropiper, water-pepper.
Sagittatum, arrow-leaved tearthumb..............
scandens, climbing false buckwheat..............
amphibium, Water ladys thutmbersion esr eee
Winidlentatend oon uo 9 a co to ee ee
Echinochloa
orusvalltawild millet. ..: ome. er soe. Soha
walteri, Walter’s millet.........
Wnudeniihed os. segs Ue Pe
Cyperus
esculentus, chufa..
erythrorhizos, red-rooted 1 nut-grass. AW Fes inetre Souler,
strigosus, nut-grass..
Unidentified. ip
Acnida altissima, water-hemp. .
Potamogeton
nodosus, longleaf pondweed.....................
pectinatus, sago ‘ig oaahlc ie Ca Eas Meee eae
foliosus, leafy pondweed. .
pusillus, small pondweed .
perfoliatus, thoroughwort pondweed.. ate eae
praelongus, white-stem pondweed. .
amplifolius, large-leaved pondweed . BAe er ice
Unidentified. .
Sagittaria
MAAC thy QUICK STAD. ones oe ee ae hake:
cuneata, wapato ......
Unidentified ..
Triticum aestivum, wheat. .
Cephalanthus occ identalis, buttonbush. Sh a
Other plants.
OccuRRENCE
(NuMBER OF
Gi1zzarDs)
VOLUME
(Cusic CenTI-
METERS)
13,725.53
6,652.11
1,801.33
1,085.11
583.40
172.68
125259
61.12
40.54
12.59
Per Cent or
Toray OrGAnNIc
ConTENTS
97.73
ee ae ee ee ee
CW
_
oon SOSSSSSS
Nmyooonwovwo
MN ot WwW [anole o}
ee
NoOOorF
nNnwmOON
August, 1959
grit and 62.75 per cent (14,044.27 cc.)
was organic in substance, tables 3 and 4.
In 80 per cent of the mallard gizzards, the
organic matter consisted of plant parts ex-
clusively.
Plant Foods (97.73 Per Cent of Or-
ganic Contents).—Plant parts, which
formed nearly 98 per cent of the food in
the mallard gizzards, appeared in all but
ANDERSON: Foop Hasits oF Micratory Ducks 295
some gizzards, leaves and stems of coon-
tail, and rootstocks or tubers of rice cut-
grass, chufa, and duck-potato constituted
the entire plant contents.
Listed in table 3 are the most important
plant foods found in the mallard gizzards
collected for this study. Corn made up al-
most half of the total volume of plant
foods; the amount of corn in the gizzards
(00 -—=== ——————
Vee ea al
me = au al
trae LL
bg Verein: reas
=) ae
ee
= au
See ee OTHER, PLANTS ===
>
Se
uw
oO “N
{e) on
PER CENT OF TOTAL PLANT FOODS
i)
oO
OCT. 16-3! NOV. 1-15
aC Ot LE Tesiictet:
2 Z ee LOO ERS
NOV. 16-30 DEC. I-15
Fig. 5—Principal plant foods consumed by mallards in Illinois from mid-October to mid-
December, 1938-1940, as determined by volumetric analyses of gizzard contents.
represent the averages for the periods indicated.
13 of the gizzards. The plant contents of
individual mallard gizzards ranged from a
trace to 20 cc. and averaged 4.86 cc. per
gizzard. The proportion of the organic
contents made up of plant structures
ranged from 95.17 per cent in 1938 to
99.28 per cent in 1940. Field observations
in the areas from which the gizzards were
collected in the 3-year period showed that
water levels fluctuated from year to year,
thus allowing native food plants to be
more easily accessible in some years than
in others.
Although there was some plant debris
that could not be identified (0.02 per
cent), 101 species of plants in the mallard
gizzards were identified. Most of the ma-
terial was in the form of seeds, but, in
The curves
was proportionally greater late in the sea-
son than early, fig. 5. Rice cutgrass, coon-
tail, wild millet or barnyard grass, and
marsh smartweed comprised more than
half of the volume of native wild foods.
The volume of emergent and moist-soil
plant parts was four times as great as the
volume of submergent vegetation.
Plant species that individually made up
less than 1.0 per cent of the total organic
volume had been ingested either in small
units by a large number of mallards or in
large volumes by a few birds. Some of the
plant particles may have been taken inci-
dentally along with more desirable foods.
Animal Foods (2.27 Per Cent of Or-
ganic Contents).—Animal matter was
found in mallard gizzards taken in each
296 Intrnors NaturaAL History SurvEY BULLETIN
Vol. 27, Art. 4
Table 4.—The most important animal foods identified in 2,825 mallard gizzards collected
in Illinois, 1938-1940.
ANIMAL
TOTAL ANIMAL: Feces:
BRYOZOA ‘statoblastse< 2 2s5 sie =
MOLLUSCA
py ieivier ics snails
Stagnicola. .
Planorbis..
Helisoma trivolvis..
Carinifex newberryi.
Physa.. ui
Campeloma. . FT eae es) CODES ey
Mostra ee. ieee Ee ne, eee
Flumnicola. .
Pleurocera. .
Unidentified Gastropoda. .
PELEcypopaA, mussels
Sphaeriidae
Pisidium. . :
Musculium transversum.
Sphaerium..
Unidentified Sphaeriidae. .
Unionidae, fresh-water clams. . Rochen at
Unidentified Pelecypoda......... Uae ee pene
UNIDENTIFIED MOLLUSCA Lf os: aci-s) tists is eee
ARTHROPODA
CRUSTACEA
Ostracoda .
Malacostraca
Decapoda, Cambarus virilis, crayfish.........
Amphipoda, Gammarus... Bee Seen ae tos
Ta a5 nee (00717 Rn NS ne ne Sha
INSECTA
Neuroptera, Corydalis cornuta, hellgrammites. . .
Ephemeroptera, Hexagenia nymphs, mayflies. . .
Odonata
Anisoptera, dragonflies
Aeshna.. Ritta long antemsern aired om
Gomphus notatus..
Unidentified Anisoptera. .
Zygoptera, Coenagrionidae nymphs, damsel-
tlies. . JUsS ARBRE
Unidentified odonata nymphs. . Bi iis ela
Homoptera, Cicadellidae, leafhoppers. eS Nap te
Hemiptera
Corixidae, Corixa, water boatmen...........
Notonectidae, Notonecta, backswimmers.. .. . .
Nepidae, Ranatra, waterscorpions...........
Belastomatidae, water bugs.................
Gerridae nymphs, water striders.............
Lygaeidae, Lygaeus, chinch bugs............
Pentatomidae, ‘stink bugsitesceiiy . opie exes
Unidentified Hemiptera.
Coleoptera
Carabidae, ground beetles. .
Halipidae..
Dytiscidae, diving beetles.
Gyrinidae, whirligig beetles. . Bente Reet
Hydrophilidae, water scavenger beetles.......
Staphylinidae, rove beetles...............4.
Buprestidae, flatheaded wood borers.........
OccuRRENCE
(NUMBER OF
GIzzARDs)
nN
=)
_
AD Pe he NNe
a
eRe PO
~ eS
Oe Bl tin’ Maal > te) NP ~
i)
_
ii)
ROA Re NOOO
VOLUME
(Cusic
CENTIMETERS)
318 74
0.30
RNOWO=SOmS
PNWWOWAN HAND
ocooooocoNnNcoeo
nN
Per Cent oF
ToTaL OrGANIC
ConrTeENTS
2.27
0.002
August, 1959 ANDERSON: Foop Hasits or Micratory Ducks 297
Table 4.—Continued.
OccuRRENCE VOLUME | Per CENT OF
ANIMAL (NuMBER OF (Cusic Tora Orcanic
GizzarDs) CENTIMETERS) ConrTENTS
Elmidae.. 1 t heoe eee
Scarabaeidae ,Aphodiusdistinctus, scarab beetles 2 0.06 0.0004
Chrysomelidae, leaf beetles. . DRM wsigieeee 1 0.26 0.002
Curculionidae, snout Bectleen tt en, 15 2.80 0.02
leinidentitied: Coleoptera. 92... asaccees oats a 4 0.50 0.004
Trichoptera, caddisfies
Hydroptilidae. . 28 0.77 0.005
Hydropsychidae, Hydrop syche larvae. 5 8.20 0.06
Unidentified Trichoptera cases. 7 3.16 0.02
Lepidoptera
Noctuidae, cutworm moths....... 2 0.29 0.002
Unidentified Lepidoptera moths. 1 0.10 0.0007
Diptera
Chironomid larvae, midges... 2.0.05. <<<. 05. 72 DON 0.19
WPabanidac Norse TIES. 4. sce oo wna 8 «tien, < 1 0.20 0.001
imidentitied Wiptera to. .06- oe wef sy or wr oes 11 Leis 0.008
Hymenoptera
Formicidae, ants. 4 t
Tiphiidae, Tiphia, tiphiid wasps. 1 t AeA Cede eee
Unidentified Insecta...... 10 S77 0.03
ARACHNIDA.. AAT 13 0.62 0.004
ACARINA, water mites. 19 t eects
CHORDATA
TPRISVETOS 5G) A cao oct ete ney ie 14 0.22 0.002
PE IUBU Aa EOS ceca ssn t cetele «ous sere, eve sibel é 1 1.00 0.007
NONFOOD
EZARAST DLC AV WORMS ee cohen ictet eye \arsks/sisieieletere, + 0: ieee sieve 1 0.20 0.001
FEATHERS. 43 4.90 0.03
UNIDENTIFIED.. 3 0.20 0.001
of the collecting periods of the fall months,
the greatest volume from November 16 to
freeze-up. Even though animal foods were
found in 580 mallard gizzards, they ap-
peared to be relatively unimportant in the
fall diet. “The animal remains in individ-
ual gizzards amounted to only a trace, ex-
cept in a few gizzards which held as much
as 12 cc. each.
An animal group was considered an im-
portant source of mallard food if it pro-
vided at least 0.1 per cent of the total or-
ganic contents. Of the animal foods found
in the mallard gizzards, table 4, about
two-thirds of the volume consisted of in-
sects and approximately one-third of snails
and mussels.
Inorganic Contents (37.25 Per Cent
of Total Contents).—Grit and other in-
organic material in individual mallard
gizzards varied from a trace to 9.4 cc. and
averaged 2.95 cc. per gizzard. Except for
calcareous material in one gizzard, the in-
organic contents consisted of stones rang-
ing in size from minute to 19 mm. (largest
dimension) ; however, in most instances,
the stones did not exceed + mm.
American Pintail
Anas acuta
In about 80 per cent of the pintail giz-
zards collected, table 5, the organic con-
tents consisted of plant material exclu-
sively. Vegetation was found in 99 per
cent of the gizzards. These percentages
seem to indicate that the pintail, in [lli-
nois at least, utilizes vegetation to a slight-
ly greater feores than does the mallard.
Of the pintail gizzards collected, 31 came
from the Mississippi River area and 850
from the Illinois River valley.
A pintail gizzard was assumed to be full
if the gross contents amounted to 14.0 cc.
or more; the average was 6.2 cc., and the
extremes ranged from a trace to 16.5 cc.
Approximately 210 gizzards were either
less than one-quarter or more than three-
quarters full, and only 6 were classified as
full. In no collecting period were the pro-
portions of full and nearly full gizzards
298 Ittrnois NaturAL History SurvEY BULLETIN Vol. 27, Art. 4
significantly greater than in any other. The gross contents of 881 pintail giz-
Fatty tissue was much in evidence around zards amounted to 5,431.91 cc., of which
most of the pintail gizzards. 37.52 per cent (2,038.20 cc.) was grit and
Table 5.—Pintail gizzards collected in Illinois in approximately 2-week periods, 1938—1940.
NumBer OF GIzzARDS
YEAR Tora
OcToBER NoveEMBER NoveMBER DECEMBER
16-31 1-15 16-30 1-15*
19380" sig foes 135 Tate 71 ia 277
[A Bo pelea wage ri 202 86 92 87 467
[ROP UD ae Makati Bae ees 76 32 29 Pm so, : 137
Olan a, Se 413 189 192 87 881
*No pintail gizzards collected in this period in 1938 and 1940; an early freeze occurred in 1938.
Table 6—The most important plant foods identified in 881 American pintail gizzards col-
lected in Illinois, 1938-1940.
i
OccuRRENCE VOLUME Per CENT oF
PLANT (NuMBER OF (Cusic Tora. Orcanic
GizzArRDs) CENTIMETERS) ConTENTS
CEOS BP 4 SAR 4 Sr J At AR Sn le ies a ee RR ed eI Um aa aera NCR rol i 96.99
Echinochloa
amano Wud Tet. ork. Se ae hb ae eae 198 436.65 12.88
walteri, Walter’s millet. . eres os MEE cee ue 98 265593 7.83
Leersia oryzoides, rice cutgras 2 RM 0 Tok Ae ai 555.29 16.36
Zea mays, corn. Ses Sata alt ann hs Ot pce Va GE 138 532.92 15.70
Cyperus
erythrorhizos, red-rooted pees ecoseesepnteeone ts 183 298.72 8.80
strigosus, nut-grass. . ash SP nee AeA Orta aide 135 131.28 3.87
PICUIPRIAS JEM AEE cle IR SRS NOS Ae 3 83 S570. 1.62
Tigre letter Saar a! sc We aia eee + 8.40 0.25
Polygonum
cocctneum, marsh smartweed.. ...... 22.620. 000s 422 126.97 a7
lapathifolium, nodding smartweed............... 257 45.96 135
hydropiperoides, mild water-pepper. Sir Ret he 56 21.10 0.62
pensylvanicum, large-seeded smartweed........... 87 18.55 0.55
punctatum, dotted smartweed..............----. 36 15.24 0.45
Perittania, Naay SithUIMDss Fe eee Pee Paws, 49 5.32 0.16
hydropiper, water-pepper. . SOG NS ne eee 16 2.95 0.09
amphibium, water lady’s phnatictbiinnlite ee dees 0s 3 0.02 0.0006
Unidentified . . eR a ale rns ats 2 0.30 0.009
Ceratophyllum demersum, Goantal to 110 216.25 6:37
Acnida altissima, water-hemp. . Be Sea een aA aoe 198 117.88 3.47
Potamogeton
nodosus, longleaf pondweed..................-.. 223 48.01 1.41
pectinatus, sago rode cae eae He eM SaaS rac 107 20.28 0.60
joliosus, leaty pondweeds 22... Sos. 4 ane ok 61 16.79 0.49
“pusillus, sinall pondweegir 2} ieee oe 16 3.04 0.09
Other Potamogeton.. ROSE Src ht cnt, See Le RR 4 t eee ia
Eragrostis hy pnoides, teal grass... Barter eae 45 81.30 2.40
Cephalanthus occidentalis, buttonbush. . SEN a ee 154 61.62 1.82
Sagittaria
latifolia, cuck-potator: gs ete eee. Fee ee 29 36.56 1.08
PINON TGR oh Sai Oran Net be iM Coma ve ee anes 1 0.01 0.0003
Lemna
MeMOF eWSeY ONC WEER hi. tes eke em 34 33.69 0.99
Winidendied 25 6e" Ge lk pate ieee ae Bt 1 1.8 0.05
MRE R NAR yf og. ante sc Bis cae ae Ses ch We 394 133.74 3.94
August, 1959 ANDERSON: Foop Hasits or Micratory Ducks 299
Table 7.—The most important animal foods identified in 881 American pintail gizzards
collected in Illinois, 1938-1940.
OccuRRENCE VOLUME Per CENT OF
ANIMAL (NuMBER OF (Cusic Tora OrGANIC
Gizzarps) CENTIMETERS) ConrTeENTS
OUT ANE, LONGING CU RAR eee RPO Ae HG fe o.oo eerie | reac cee 102.27 3.01
MRMOZOAstatoblasts. o. 1: saacsds «aga ssowe ae een 15 1.44 0.04
MOLLUSCA
GAsTROPODA, snails
Planorbis.. Ht 2 t ee
Helisoma trivolvis.. ac) «eta ee ees oat 1 0.70 0.02
Gyraulis parvis. 5. reeves e veces 1 0.10 0.003
Physa gyrina.. 1 0.10 0.003
Campeloma.. + 3.70 0.11
Lioplax subglobosus . . 1 0.30 0.009
Amnicola..... l 0.40 0.01
Unidentified Gastropoda. . 22 15.54 0.46
PELEcypopDaA, mussels
Sphaeriidae
IES MUD 0 Bia e 4 5.08 Onis
Musculium transversum. Ee reoiete Gh, Gack 2 2.70 0.08
Sphaerium....... Saya e eer enter 7 6.70 0.20
Unionidae, fresh-water clams. ee 1 1.70 0.05
Unidentified Pelecypoda.. ieatiarer hacia 8 4.30 0.13
UnwentirieD MOLLUSCA........ 00-000 c ee eee. 12 6.07 0.18
ARTHROPODA
CRUSTACEA
SERA COG AEM nego aera t ety ct 3 eco tease acute) cess 3 0.50 0.01
Malacostraca
Amphipoda, Gammarus... .0..-.26200+5.5--% 1 t aS ey
ISG POC AMEASEL/WISN Wa Montene.) ne Petes Meee inees 2 0.11 0.003
INSECTA
Orthoptera, grasshoppers
INADADHORG NALS sos 92 6000 005 SO Sade ee oe De 1 0.20 0.006
Ephemeroptera, mayflies
ICIPRATUTE IONS ao coc co eeoe oo Bene Da be de: 9 4.50 0.13
TT BRUSASTS 5G 9) | URES SEINE ae a Se a ea i 0.10 0.003
Odonata
Anisoptera, ee
AURORS TSAI she Pesede each aeaet teat op tae 3 2.90 0.09
Anisoptera nymphs. . Saath oy Ret eh Bieler oe 1 0.10 0.003
Zygoptera, damselnies
COST NAVE OTTTES Ea 1 0.10 0.003
EXERT TVD) Sing g cau co beguen acess 08s 2 0.90 0.03
Wnidentinedt@donatawe nae + tree en ae 2 0.90 0.03
Hemiptera
Corixidae, Corixa, water boatmen........... 27 6/3 0.20
Nepidae, Ranatra, waterscorpions........... 1 0.20 0.006
Pelastomatidae, predaceous water bugs..... . 5 2-53 0.07
Miridae, Lygus lineolaris . ee 1 0.02 0.0006
Lygaeidae, Lygaeus kalmii, chinch h bugs. Hele 1 0.03 0.0009
Unidentified Hemiptera. . SO 1 t alae
Coleoptera
Carabidae, ground beetles
CASRD HB NALPSWWALIG Is 6668 ob ye ee oec ase 1 0.04 0.001
WaidentitediCarabidaettcme cs) eens oe 9 t ee
Haliplidae.. a: Le es 1 6.10 0.003
Dytiscidae, diving beetles
Colymbetes.. ET con ee eat 1 0.20 0.006
Unidentified ‘Dytiscidae... . 41 7.30 0.22
Hydrophilidae larvae, water scavenger beetles 2 0.20 0.006
Staphylinidae, rove beetles ...... ey 1 0.20 0.006
Scarabaeidae, Aphodius distinctus, scarab
SESE Re Oe eS alee tren, 1 0.05 0.001
300 Intinois NatrurAL History Survey BULLETIN Vol. 27, Art. 4
Table 7.—Continued.
OccuRRENCE VOLUME Per CENT OF
ANIMAL (NuMBER OF (Cusic Tora Orcanic
GizzaArRDs) CENTIMETERS) ConrTeNTS
Chrysomelidae, leaf beetles
Diabrotica undecimpunctata howardi....... 1 t 5 ee
Lseus: ed 1 0.20 0.006
Unidentified ‘Chrysomelidae. . Tce 1 t SAO ALN
Curculionidae, snout beetles........... 2 t
Trichoptera
Hydroptilidae cases, caddisflies.............. 32 3.42 0.10
Hydropsychidae, Hydropsyche.............. 1 0.30 0.009
Unidentified Trichoptera............ 5 0.25 0.007
Diptera
Chironomidae larvae, midges............. 39 18.09 0.53
Unidentified Dipteray en. ee eee 2 0.03 0.0009
Hymenoptera
Ichneumonidae, ichneumon flies............. 1 t Be ie a
Tiphiidae, Tiphia.. 1 0.10 0.003
Formicidae, ants. NS RON. ree A D 0.10 0.003
Unidentified Hymenoptera... ae ety Nia. 1 0.96 0.03
Unidentified Insecta. . Pry s 1 t BN ease
ARACHNIDA
Araneae, spiders
Argiopoidea. . in data eee cae eee 1 0.03 0.0009
Unidentified Araneae. 1 t kee ee
Unidentified Arachnida. . Be SAA Hy 2 3 t én Se
Acarina, Hydracarina, Writer unites! <u st es 18 0.22 0.006
CHORDATA
Pisces, fish.. 2 t Re
NONFOOD, feathers. . 15 1.23 0.04
UNIDENTIFIED. . 1 0.60 0.02
62.48 per cent (3,393.71 cc.) was organic
material, tables 6 and 7.
Plant Foods (96.99 Per Cent of Or-
ganic Contents).—Plant parts, which
formed approximately 97 per cent of the
organic matter found in the pintail giz-
zards, appeared in all but eight of the giz-
zards. The plant contents of individual
gizzards ranged from a trace to 14.0 cc.
and averaged 3.7 cc. per gizzard. The
volume of plant structures in the pintail
gizzards was nearly 8 per cent greater in
1939 and 1940 than in 1938. More moist-
soil plants were available to migrating
ducks in 1939 and 1940 than in 1938, as
indicated in a study by Bellrose (1941:
252-3). Mboist-soil plants were more
abundant along the Illinois River than
along the Mississippi, a condition reflected
in the larger percentage of structures of
these plants noted in gizzards collected
along the I[]linois.
Some plant debris in the 881 pintail giz-
zards could not be identified ; however, 73
species of emergent, submergent, moist-
soil, and terrestrial plants were classified.
In most of these gizzards, seeds comprised
the greater volume; in a few, the entire
contents consisted of vegetative parts from
such plants as rice cutgrass, duck-potato,
and coontail.
Any plant providing at least 1.0 per
cent of the total organic contents of giz-
zards of the pintail was regarded as an
important source of food for this species,
table 6. Principal food plants were the
millets, rice cutgrass, corn, the nut-grasses,
marsh smartweed, nodding smartweed,
coontail, water-hemp, longleaf pondweed,
teal grass, buttonbush, duck-potato, known
also as common arrowhead, and duck-
weed.
Laboratory analyses of gizzard contents
indicated that the pintails represented fed
primarily on wild native plants, appar-
ently taking corn only when the wild food
supply was low. Field observations cor-
roborated the laboratory findings; pintails
were seldom observed among the mallard
flocks flying to and from cornfields. It was
noted that pintails used corn more fre-
quently along the Mississippi River, where
August, 1959
moist-soil plants were decidedly less abun-
dant, than in the Illinois River valley.
Animal Foods (3.01 Per Cent of Or-
ganic Contents).—Animal matter was
found in a few pintail gizzards taken in
each collecting period; it was most abun-
dant during the period October 16-31.
This type of food was found in 202 of the
pintail gizzards, but only 8 contained ani-
mal matter exclusively.
Most pintail gizzards contained only
traces of animal matter; however, one
gizzard contained 11.5 cc. of midge larvae.
ANDERSON: Foop Hasits oF Micratrory Ducks
301
a larger percentage of animal matter than
did those of the mallard or the pintail.
Plant structures occurred in 53 per cent of
the blue-winged teal gizzards analyzed.
Most blue-winged teals leave Illinois be-
fore the middle of November, and only
one gizzard representing the blue-wings
was collected after that time, table 8.
Only eight gizzards of the blue-winged
teal were collected from the Mississippi
River region.
A blue-winged teal gizzard was consid-
ered full if the gross contents amounted to
Table 8.—Blue-winged teal gizzards collected in Illinois in approximately 2-week periods,
1938-1940.
NumBer OF GizzaRDs
YEAR = Tora.
OcroBeER NoveMBER NoveMBER DECEMBER
16-31 1-15 16-30 1-15
MOS OM eye ee alae 62 ea ae 1 Ag reas SIE e 63
MOBO Bee As. a eitiicc s 34 30 BE ae ea Leese Oe, eed eee 64
OLGA ra 98 30 il 0 129
The volume of animal foods averaged 0.51
cc. per gizzard.
An animal group represented by at least
0.1 per cent of the total organic volume
was considered important in the diet of
the pintail, table 7. Of the animal foods
in the pintail gizzards, +9.62 per cent con-
sisted of insects and +6.34 per cent repre-
sented the phylum Mollusca, about
equally divided between snails and_ bi-
valves. Feathers, crustaceans, fish, water
mites, and unidentified material were rep-
resented in the remaining percentage.
Inorganic Contents (37.52 Per Cent
of Total Contents).—The volume of in-
organic material in individual pintail giz-
zards ranged from a trace to 10.1 cc. and
averaged 2.31 cc. per gizzard. Grit par-
ticles varied considerably in shape, rough-
ness, and size. About 64 per cent of the
particles ranged from minute to + mm., 26
per cent between 4 and 8 mm., and 10
per cent from 8 to 18 mm. (largest dimen-
sion).
Blue-Winged Teal
Anas discors
In the material collected for this study,
gizzards of the blue-winged teal contained
3.7 cc. Degrees of fullness varied greatly
among the samples, and the contents of
the individual gizzards ranged from a
trace to 3.9 cc.; the average amounted to
2.03 cc. per gizzard, slightly over half of
the capacity.
The total contents of the 129 gizzards
collected from blue-winged teals amounted
to 261.87 cc., of which 39.35 per cent
(103.05 cc.) was inorganic and 60.65 per
cent (158.82 cc.) was organic material.
Plant Foods (83.63 Per Cent of Or-
ganic Contents ).—Plant structures consti-
tuted more than four-fifths of the organic
food present in the blue-winged teal giz-
zards. The plant contents of individual
gizzards ranged from a trace to 3 cc.; the
average was | cc. More moist-soil plants
were accessible in 1939 and 1940 than in
1938; the plant contents per gizzard aver-
aged 0.7 cc. in 1938, 1.3 cc. in 1939, and
0.9 cc. in 1940.
Thirty-nine species of plants from the
gizzards of the blue-wings were identified.
These plants were predominantly moist-
soil species. “Ihe major portion of the ma-
terial consisted of seeds and seed coats;
however, stem and leaf fragments of coon-
tail and sago pondweed were present.
302
A plant making up at least 1.0 per cent
of the organic material was considered an
important blue-winged teal food, table 9.
Thirteen species and one genus, aggregat-
ing 76.66 per cent of the organic contents,
were in this category: three nut-grasses,
two millets, coontail, water-hemp, marsh
Ittrnois NaATurRAL History SurvEY BULLETIN
Vol. 27, Art. 4
diet than that of the mallard or the pintail.
In the majority of blue-winged teal giz-
zards containing animal parts, the animal
contents ranged in volume from 0.1 to 1.0
cc.; some gizzards contained only a trace
of animal matter and others as much as
2 cc. each. The animal groups considered
Table 9—The most important plant foods identified in 129 blue-winged teal gizzards col-
lected in Illinois, 1938-1940.
PLANT
TOLAL RAIN Dene coe Rae ae oly citer ere eer
Cyperus
erythrorhizos, red-rooted nut-grass. .
StTEZOSUS, MUL-BIASS.. 6. ee eee
Premier CEA Ses eS bc 2 Ee CES eee
WRG eHEthed ge a ete ei Se eR re eneten ah
Echinochloa
CruseaI: Wi TAMNEt, on ie oi ae ee ee ewe
Walters Walter 5 MNets . 5 ee s2 vos ss ee oe eat
Ceratophyllum
demersum, coontail. .
Unidentified. . Be at ite Gee
Acnida altissima, ‘water-hemp. .
Polygonum
coccineum, marsh smartweed. .
lapathifolium, nodding smartweed .
pensylvanicum, large-seeded sm artweed. Pees Sater
punctatum, dotted smartweed. .
Other Polygonum..
Eragrostis hypnoides, teal grass. .
Cephalanthus occidentalis, buttonbush. .
Panicum dichotomiflorum, fall panic- grass. Aes
Lemna minor, \esser duckweed...........-+.+-+-+:
[SGETSIG) OTY ZOIGES.. TICE: CULDTASS bari aie pie sae sane oe
Potamogeton
epihydrus, ribbon-leaf Cares
nodosus, longleaf pondweed. .
pectinatus, sago pondweed...... RAL een eee ee
MES E CRAIO RTO 5 5 cic sala onde ass vais STE ee es
ener Platts aie tok es: ois ot (ou et rae hoa ees
OccuRRENCE | VoLUME Per CENT OF
(NuMBER OF (Cusic Tora OrGanic
G1zzarDs) CENTIMETERS) ConrENTS
132.82 83.63
81 66.00 41.56
33 4.50 2.83
18 4.80 3.02
1 0.20 0.13
15 7.30 4.60
5 2.80 1.76
9 4.46 2.81
4 4.30 2a
47 6.68 4.21
43 4.66 2.93
45 0.79 0.50
12 0.48 0.30
9 0.03 0.02
10 t ative Re
12 5.92 YE.
15 3.97 2.50
4 3.10 1.95
6 2.89 1.82
10 253 oo
1 1.30 0.82
10 0.55 0.35
5 0:27 0.17
4 0.01 0.01
96 5.28 3.32
smartweed, teal grass, buttonbush, fall
panic-grass, lesser duckweed, rice cutgrass,
and the pondweeds as a group.
Any plant species or group represented
by less than 1.0 per cent of the organic
contents was considered to be of secondary
importance. Plant parts of species in this
category were found in many gizzards in
small volumes, or in a few gizzards in
large volumes.
Animal Foods (16.37 Per Cent of
Organic Contents).—Because the blue-
winged teal feeds extensively in shallow
water areas, animal foods might be ex-
pected to constitute a greater part of its
most important were those that contrib-
uted at least 0.1 per cent each to the or-
ganic contents, table 10.
About 74 per cent of the volume of ani-
mal material in the gizzards of blue-wings
consisted of insects. “The Mollusca group
made up about 17 per cent of the animal
material. The crustaceans comprised about
5 per cent.
Inorganic Contents (39.35 Per Cent
of Total Contents).—Grit present in in-
dividual blue-winged teal gizzards ranged
in volume from a trace to 2 cc. and aver-
aged 0.4 cc. Particles varied in size from
sand to gravel stones of + mm. (largest
August, 1959
ANDERSON: Foop Hasits or Micratory Ducks 303
Table 10.—The most important animal foods identified in 129 blue-winged teal gizzards
collected in Illinois, 1938-1940.
OccuRRENCE VOLUME Per CENT oF
ANIMAL (NUMBER OF (Cusic Tora OrGANIC
GIzzARDs) CENTIMETERS) ConreNTS
WMO Wei ee A INUUNGA DE enlists ao aude su a: A/a avo ans ERO 26.00 16.37
BRYOZOA statoblasts..... 11 0.80 0.50
MOLLUSCA
GAsTROPODA, snails
Gyraulus parous ee 1 0.10 0.06
Unidentified Gastropoda. . 6 0.90 0.57
PELEcypopA, mussels
ee ee en be. a eee | 0.20 0.13
Sphaerium. 3 0.70 0.44
UNIDENTIFIED Motuvsca.. 10 21,510) Sy,
ARTHROPODA
CRUSTACEA
"° SIS/ 50 Me, ena ee ae 1 1.00 0.63
OSCCTC OC AE URN ET ce! tie ante heey het nde, BR be 11 0.40 0.25
INSECTA
Ephemeroptera, Hexagenia, mayflies .......... 3 0.10 0.06
Hemiptera, Corixa, water boatmen............ 29 8.35 S625)
Coleoptera
Carabidae: ground beetles...........220.5.. 1 t aft
Dytiscidac, diving beetles... 5. sgeene += - 4 .10 0.06
Gyrinidae, whirligig beetles................. 1 t Pcs
Curculionidae, snout beetles................ 1 0.10 0.06
Trichoptera
Hydroptilidae cases, caddisfiies.............. 14 0.10 0.06
Unidentified Trichoptera cases.............. 1 0.10 0.06
Diptera, Seemomidae, MMA PES s . cet operant: 26 9.25 5.82
Unidentified Insecta. . ee 1 1.20 0.75
ARACHNIDA.. Ns 1 t Ro te
ACARINA, Hydracarina, water mites. 5 0.10 0.06
NONFOOD, feathers. . 1 t Bie
dimension ) ; however, the particles seldom
exceeded 2 mm. each.
Green-Winged Teal
Anas carolinensis
The green-winged teal gizzards col-
lected for this study contained a larger
proportion of animal matter than was
found in gizzards of the mallard, pintail,
or blue-winged teal; yet the green-
winged teal proved to be very much a veg-
etarian. ‘“Iwenty-seven of the gizzards
listed in table 11 were collected along the
Mississippi River and 366 along the IIli-
nois River.
A green-winged teal gizzard was con-
sidered full if the gross contents amounted
to 3.5 cc. or more. The contents of indi-
vidual gizzards ranged in volume from 0.4
to 4.5 cc. and averaged 1.0 cc. per gizzard.
Over four-fifths of the gizzards were more
than one-fourth full.
The total contents of all green-winged
teal gizzards amounted to 778.30 cc., of
which 41.94 per cent (326.45 cc.) was in-
organic and 58.06 per cent (451.85 cc.)
Was organic.
Plant Foods (84.96 Per Cent of Or-
ganic Contents ).—Plant parts were found
in 390 of the 393 green-winged teal giz-
zards collected; only grit was present in
the other 3. Plant food in individual giz-
zards ranged from a trace to 2.8 cc. in vol-
ume and averaged 0.98 cc. per gizzard. As
with gizzards of the blue-winged teal and
the pintail, the green-winged gizzards
contained a larger proportion of plant ma-
terial in 1939 and 1940 than in 1938,
probably because of greater availability of
moist-soil species. “he average volume of
plant material per gizzard was 0.78 cc. in
1938) 22 cer im 1939)-and?0:90) cc. in
1940. The quantity of plant structures
was greater in green-winged teal gizzards
collected along the Illinois River than in
those obtained along the Mississippi River.
304 I_tinois NarurAL History SurvEY BULLETIN Vol. 27, Art. 4
This fact probably reflected differences in tures representing 63 species of emergent,
plant food availability. moist-soil, submergent, and __ terrestrial
In the gizzards of the green-wings, plants were identified. Seeds and seed-
there was some plant debris (0.09 per coat fragments comprised the bulk of the
cent) that could not be identified; struc- plant structures, although coontail stems
Table 11—Green-winged teal gizzards collected in Illinois in approximately 2-week periods,
1938-1940.
NuMBER OF GIzzARDS
YEAR F Tora.
OcTOBER NovEMBER NoveMBER DECEMBER
16-31 1-15 16-30 1-15
LOS Re he oe aes cet 85 62 54 ae See 201
DOSO eae ae 31 51 47 35 164
[940 es si 5 6 14 3 28
RORY Aree 121 119 ws 38 393
Table 12.—The most important plant foods identified in 393 green-winged teal gizzards
collected in Illinois, 1938-1940.
|
OccuRRENCE VOLUME | Per Cent oF
PLANT (NUMBER OF (Cusic Tota OrGANIC
GizzarDs) | CENTIMETERS) ConTeNTS
TEIN, 55% Fete) SAR area Gua eee soe eee 383.91 84.96
Cyperus
erythrorhizos, red-rooted nut-grass.............. 212 135.98 30.09
BOER a STARE SEAS iso ca ale wha 90 29.30 6.48
IPMS EMME en go cuss ee Mena ine Be uae os 73 19.06 4.22
Dg eA one a perch aa RRR RR PR OR car Be ee SAA 7 0.90 0.20
Echinochloa
Pr USeeie, WI MACE eo ee 75 31.20 6.90
Rar a VA Alter 8 SOE oo dec Fs cin tk eS 39 14.51 P|
EVES FETE Fs as Oe Pa 1 t ote:
Eragrostis
PEDTUSEES RCA TARR Se. Shee ee eee: 30 paler 4.81
Riteea na RSs eke Aunae bow as 2 0.40 0.09
Polygonum
coccineum, marsh smartweed................... 10 10.85 2.40
lapathifolium, nodding smartweed.............. 128 5 42 PAS
pens vlvanicum, large-seeded smartweed......... 35 3.00 0.66
punctatum, dotted smartweed.................. 14 0.11 0.02
hydropiper, eee, ee ne anes Care 5 0.10 0.02
Persiiasia, tanya tambo.) oo aes 3 le ces 14 0.05 0.01
Other Polygonum.. Pe aes 11 1.55 0.34
Lemna minor, lesser duckweed . ees eiaehha wre ROE: 58 17.92 3.97
Ceratophyllum demersum, pana ae cae oe 26 16.65 3.68
SUUE DOE SHA hae: oo scasl tae ak ee ee 23 11.78 2.61
Leersia oryzoides, rice cutgrass. Sc Sdenee es. 34 8.97 i
Acnida altissima, WIE CII oh ck! 5. ee Se eae 131 8.27 1.83
Potamogeton
foliosus, leafy co eile yee ae eae 23 3.45 0.76
nodosus, a eed: ee a ee 27 2.50 0.55
pusillus, small ponNweed oor oe Rs 1. 11 0.81 0.18
pectinatus, sago pondweed. . See Ree ee 15 0.49 0.11
epthydrus, ribbon-leaf f pondweed.. tar Pheer ae 1 0.05 0.01
Other Potamogeton.. e Pa og ete ee * 0.15 0.03
Zea mays, corn. Bes om 12 7.05 1.56
Cephalanthus occidentalis, buttonbush. . Ao ae. 35 5.46 1331
Sagitaria latifolia, duck-potato.. Seale te ice 21 e634 1.02
Other plants. . ssnoe Rep ac ere ale 25) 21.88 4 84
° "Lint. er
Lb el ee ee
August, 1959 ANDERSON: Foop Hasits or Micratory Ducks
and leaves and duckweed particles were
numerous.
Plant foods that contributed at least 1.0
per cent each to the total organic contents
305
of the gizzards of green-wings and in the
aggregate amounted to more than 75 per
cent of the organic contents were three
nut-grasses, two millets, teal grass, marsh
Table 13.—The most important animal foods identified in 393 green-winged teal gizzards
collected in Illinois, 1938-1940.
VOLUME Per CENT OF
ANIMAL (Cusic Tora Orcanic
CENTIMETERS) ConTENTS
ODT YS 0s OS ee ee 67 .94 15 04
BIRSOZOAVstatoblastss.. 22.0 nhs eed hs torn daa 5e38 iil
MOLLUSCA
GASTROPODA, snails
Gyraulus parvus. . 0.08 0.02
Physa gyrina.. LAO 0.38
Unidentified Gastropoda. . a Caen ee 2 8.26 1.83
PeLecypona, Sphaerium, eeadishellstint ty kon «. 0.10 0.02
Uniwentiriep Moutusca.. ue 4.56 1.01
ARTHROPODA
CRUSTACEA
Branchiopoda
Fairy shrimps. . 1.30 0.29
Unidentified Branchiopoda. . 0.10 0.02
Copepoda
Cyclops. . 1.40 0.31
Canthocampus.. t eraraes
Unidentified Copepoda. . 1.20 0.27
Ostracoda
Candona.. 0.02 0.004
Cypris.. 0.01 0.002
Unidentified Ostracoda. . 1.43 O32
Malacostraca
PPI POGA, GUM MATHS 2% ie. ou asin canes ee t ee
WSOP AeA SEIIIES on haha pies in 3 wana WV ee 0.10 0.02
INSECTA
Orthoptera, Tettigoniidae, grasshoppers ....... 0.30 0.07
Ephemeroptera, mayflies
em aerm ia Ny MIPS: tric 8 eae. sats ste Fs 9 ons 0.30 0.07
TEP STS) 0] SE ee ene Te eR ee t es
Odonata
Anisoptera, 4eshna, dragonflies..... . 0.30 0.07
Zygoptera, Coenagrionidae, damselflies. . 3.60 0.80
Odonata nymphs. . cai 1.50 0.33
Hemiptera, Corixa, water boatmen. 15.34 3.39
Coleoptera
Carabidae, ground beetles.................. 0.11 0.02
Dytscidac, diving beetles... 0... e265... 2... 0.67 Onis
Gyrinidae, whirligig beetles. . Scores t Sate
Staphylinidae, rove beetles .........5...... t
Elmidae.. : ee t
Chrysomelidae, Diabrotica undecim punctata
Rowardi leat beetles: ).. 4.4. 0.9042. «eee ae t tee
Unidentified aleuptentan. cece fet hinds 0.05 0.01
Trichoptera
Hydroptilidae cases, caddisflies.............. 1.24 0.27
Unidentified Trichoptera. . 0.20 0.04
Diptera, Chironomidae larvae, midges. . 17.24 3.82
Hymenoptera
Ichneumonidae, ichneumon fies. . 0.05 0.01
Formicidae, ants. rca t Dee
Unidentified Insecta. . 0.12 0.03
ARACHNIDA.. aie t Biro
Acarina, H. pdracarina, water mites. 0.04 0.009
NONFOOD, feathers. . APS me 1-29 0.29
306 Ittinois NaTurAL History Survey BULLETIN
smartweed, nodding smartweed, lesser
duckweed, coontail, rice cutgrass, water-
hemp, the pondweeds as a group, corn, but-
tonbush, and duck-potato, table 12. Most
of these plants grow on mud flats or moist
sand bars.
Animal Foods (15.04 Per Cent of
Organic Contents).—Animal matter ap-
peared in more than half of the gizzards
of the green-winged teals and in a few giz-
zards in greater volume than the plant
foods. It was found in gizzards collected
in all four periods but in the greatest per-
centage in those collected from October
16 through November 15.
Individual gizzards of the green-winged
teals contained a trace to 3.1 cc. of animal
parts and averaged 0.31 cc. More than a
third of them contained 0.1 to 1.0 cc. of
tents.
Vol. 27, Art 4
animal matter each. An animal group rep-
resenting at least 0.1 per cent of the total
organic contents of the gizzards of these
teals was considered important, table 13.
Insects comprised a little less than two-
thirds of the volume of animal matter in
gizzards of the green-wings. In greatest
volumes were midge larvae, water boat-
men, and Odonata nymphs. The Mollusca
group, represented principally by snails,
made up 21.64 per cent of the animal con-
Other important animal foods
were Bryozoa statoblasts and crustaceans.
Inorganic Contents (41.94 Per Cent
of Total Contents).—In most of the
green-winged teal gizzards collected, al-
most one-half of the gross contents con-
sisted of inorganic material. The volume
of inorganic matter in individual gizzards
Table 14.—Baldpate gizzards collected in Illinois in approximately 2-week periods, 1938-1940.
NuMBER OF GizzARDS
YEAR
OcTOBER NoveMBER
16-31 1-15
WRG s aka th oe 64 23
je i an Se eT ai 19 30
Ear a SS eels eee 4 6
fA) «71 ooh hea a 87 59
TOTAL
NoveMBER DECEMBER
16-30 1-15
1 Petre te 88
3 9 6]
1 tS: 11
5 9 160
Table 15.—The most important plant foods identified in 160 baldpate gizzards collected
in Illinois, 1938-1940.
PLANT
ENE IO COR TY AA! SARA Re cig ADU aE ea tg
Ceratophyllum demersum, coontail...............
Potamogeton
nodosus, longleaf pondweed............
pectinatus, sago pondweed. :
foliosus, leafy pondweed...........
Leersia oryzoides, rice cutgrass.......
Polygonum
coccineum, marsh smartweed. .
pensyluanicum, large-seeded smartweed..... .
lapathifolium, nodding smartweed.
hydropiperoides, mild water-pepper.
punctatum, dotted smartweed. .
Other Polygonum..
Cephalanthus occidentalis, buttonbush.
Ulothrix zonata, algae... eye
Zea mays, corn.
Sagittaria latifolia, ‘duck- ‘Potato..
Lemna minor, lesser duckweed.
Other plants.. ee
OccuRRENCE VOLUME Per Cent OF
(NUMBER OF (CuBic Tora OrGANIc
GizzarDs) CENTIMETERS) ConrTeENTS
318.75 93.66
116 237 93 69 91
24 Sree 1.70
10 4.20 1:23
4 4.10 1.20
12 12.60 3.70
60 10.87 3.19
5 0.25 0.07
18 0.14 0.04
5 0.10 0.03
5 0.03 0.01
1 0.10 0.03
28 9 20 2.70
3 8.60 2.53
4 6.80 2.00
3 5.10 1.50
7 4 20 1.23
56 8 76 2257
ele ieee
August, 1959 ANDERSON :
ranged from a trace to 1.9 cc. and aver-
aged 0.8 cc. Gravel particles varied in size
from minute to 9 mm. (largest dimen-
sion), but seldom exceeded 3 mm. Very
little other inorganic material was present
in gizzards containing grit particles 7, 8,
or 9 mm. in size.
Baldpate
Mareca americana
Analyses of the contents of gizzards col-
lected for this study indicated that in IIli-
nois the baldpate, or widgeon, during the
fall months is primarily a vegetarian; it
appears to ingest animal foods only inci-
dentally with plant parts. Because the
baldpate reaches its peak population in this
state early in the fall, most of the gizzards
representing this species were obtained
during the first two collecting periods,
table 14. Of the 160 samples, only 8 were
Foop Hasits or Micratory Ducks
307
collected from stations along the Missis-
sippi River.
A baldpate gizzard, about as large as
that of a mallard or pintail, was consid-
ered to have a capacity of 13 cc. Gross
contents of individual gizzards ranged
from 1.4 to 11.0 cc. and averaged 4.99 cc.
Nearly one-fifth of the gizzards were less
than one-quarter full and none was full.
Even on gizzards in which the contents
averaged less than half the gizzard ca-
pacity, fatty tissue was prevalent.
The gross material in the 160 gizzards
of baldpates totaled 799.82 cc. Of this
amount, 57.45 per cent (459.50 cc.) con-
sisted of grit and the remaining 42.55 per
cent (340.32 cc.) consisted of plant and
animal parts.
Plant Foods (93.66 Per Cent of Or-
ganic Contents).—In 1938, plant struc-
tures made up 91 per cent of the organic
Table 16—The most important animal foods identified in 160 baldpate gizzards collected
in Illinois, 1938-1940.
ANIMAL
WOU AIEANIM ATL...
BR VOZOA ‘statoblasts: 1.6 i) aa 2 ot Biwi ee wate >
MOLLUSCA
GAsTRopODA, snails
Gyraulus parvus. .
Physa.
Unidentified Gastropoda. .
Untwentirtep Moutusca shells. .
ARTHROFODA
(GRUISTACEANASC/I1150 cre. ho clots nn tila ati aioe. sie «
INSECTA
Ephemeroptera, Hexagenia nymphs, mayflies.. .
Odonata nymphs, dragonfies
Homoptera, Cicadellidae, eu hones
Draeculacephala. . ; nes
Unidentified Homoptera...
Hemiptera
Conixanwater boatinenincn. mee ricei cele 1
MEN ELISINUSITE OL GIUSA routine nh treks, <a; + ave eeicl eseushe 8 eo
Coleoptera
Carabidae, Omophron. .
Dytiscidae, diving beetles.
Scarabaeidae, Geotrupes, scarab beetles.......
Chrysomelidae, Diadrotica, leaf beetles.....
Trichoptera
Hydroptilidae cases, caddisflies...........-.-.
Unidentified Trichoptera cases.............-
Diptera
Chironomidae larvae, se or
Unidentified Diptera larvae..
ARACHNIDA.. Se
ACARINA, Hydracarina, water mites.
NONFOOD, feathers. . em ee
OccuRRENCE VOLUME Per CENT OF
(NuMBER OF (Cusic Torat Orcanic
GizzArRDs) CENTIMETERS) CONTENTS
Pil EV 6.34
5 0.20 0.06
1 0.30 0.09
1 0.20 0.06
3 2.10 0.62
1 0.10 0.03
1 0.05 0.015
1 0.10 0.03
1 1.20 0.35
1 t
1 t
17 14.00 4.11
1 t chore
1 0.20 0.06
4 1.90 0.56
1 0.20 0.06
] t chee
5 0.02 0.006
2: 0.10 0.03
2 0.90 0.26
1 t aerate
1 t
2 t
2 t
308 [Lxuino1is NatrurAL History Survey BULLETIN
contents of the baldpate gizzards; in 1939
and 1940 they represented 100 per cent of
the organic material. Volumes in individ-
ual gizzards varied considerably; in a
number of gizzards only a trace of plant
material was found, while in others the
plant contents ranged up to 6.5 cc. ‘The
average was 1.99 cc., a rather low volume
for the size of the gizzard.
Plant debris amounting to 0.33 per cent
of the organic contents of the baldpate giz-
zards could not be keyed to species because
of its finely ground condition ; however, 3+
species of plants were identified. The bulk
of this plant material consisted of stems
and leaves of coontail. The remaining
plant material, except for algae and duck-
weed, consisted of seeds and seed coats.
Of 11 plants important to the baldpate
(plants constituting at least 1.0 per cent of
the total organic contents of the baldpate
gizzards collected), coontail appeared to
be the most important, table 15. Nearly
three-fourths of the organic volume con-
sisted of this plant. Field observations
showed that baldpate concentrations were
usually found in lakes or sloughs where
coontail beds flourished. Corn was found
in only four baldpate gizzards, and this
was probably bait. Moist-soil plants in
some gizzards indicated the birds had fed
on flooded mud flats.
Plant species of lesser importance, those
that contributed less than 1.0 per cent of
the organic contents of the baldpate giz-
zards, were taken by only a few baldpates
but in fairly large amounts. Most of these
were moist-soil plants important to the
teals and the pintail.
Animal Foods (6.34 Per Cent of Or-
ganic Contents).—Most of the animal
foods found in the baldpate gizzards, table
16, were species associated with submerged
plant beds and had been ingested probably
Vol. 27, Art. 4
while the birds were browsing on coontail.
Volumes in individual gizzards ranged
from a trace to 6.8 cc., most of them less
than 0.5 ce.
Aquatic insects, most of them water
boatmen, comprised more than four-fifths
of the animal material found in the bald-
pate gizzards. The Mollusca group was
represented only by univalves. Bryozoans,
Water mites, crustaceans, and feathers
were present in very small amounts.
Inorganic Contents (57.45 Per Cent
of Votal Contents).—The inorganic ma-
terial in individual baldpate gizzards var-
ied in volume from 0.5 to 5.1 cc. and av-
eraged 2.87 cc. Most of the grit consisted
of fine, white sand crystals. In four-fifths
of the gizzards, stones were less than 2
mm. in size (largest dimension). In the
remaining 20 per cent, there were, in ad-
dition to the fine sand, a few stones rang-
ing from 3 to 10 mm. in size.
Gadwall
Anas strepera
This study indicated that the gadwall,
like the baldpate, is primarily a vegetarian
in the fall months in Illinois. Four-fifths
of the gadwall gizzards collected for this
study contained no animal material. Ma-
terial was collected for the first three of
the four collecting periods in the years of
this study, table 17. Of the 98 gizzards
obtained, only 7 were from the Mississippi
River.
A gadwall gizzard was considered to
have a capacity of 14 cc. None was filled
to capacity; the contents of individual giz-
zards ranged in volume from 1.0 to 10.5
cc. and averaged 5.2 cc. One gizzard was
completely empty; its condition indicated
the bird was emaciated and probably sick.
About one-tenth of the gizzards were less
than one-quarter full; in these the con-
Table 17.—Gadwall gizzards collected in Illinois in approximately 2-week periods, 1938-1940.
NuMBER OF GiIzzARDS
YEAR
OcrToBER NovEMBER
16-31 1-15
KES} Saami ied ae So ae 19 4
[Ik 1? Laas aca pete ee ota 7 38
TSAO ees hs) sane 1 9
IRATE RO ee eer 27 51
Tora.
NoveMBER DECEMBER
16-30 1-15
6 eee 29
14 pe Bs 59
Eee ie 10
20 0 98
August, 1959
tents were mostly grit. No gizzard was
more than three-quarters full; yet most
birds were apparently healthy when shot,
since fatty tissue was evident.
The total contents of the gadwall giz-
zards amounted to 509.29 cc., of which
74.04 per cent (377.10 cc.) was grit and
25.96 per cent (132.19 cc.) was organic
ANDERSON: |oop Hasits or Micratory Ducks
309
material. Vegetable foods comprised 97.21
per cent and animal foods 2.79 per cent of
the organic contents, tables 18 and 19.
Plant Foods (97.21 Per Cent of Or-
ganic Contents ).—Plant items were found
in 89 of the 98 gadwall gizzards; only
gritty material was found in the remain-
ing 9. The plant food contents of indi-
Table 18.—The most important plant foods identified in 98 gadwall gizzards collected in
Illinois, 1938-1940.
OccuRRENCE VOLUME Per CENT OF
PLANT (NuMBER OF (Cusic Torat OrGANIC
G1zzARDs) CENTIMETERS) CONTENTS
Mee ae er TAI Arete oobi oes GB: Baw OM dress SS oleae wae wanna 128 .50 97 .21
Ceratophyllum demersum, coontail. . 48 94.98 71.85
Algae. . Hid Nice Aare RE 13 9.80 7.41
Polygonum
poceinenm, Matsh smartweed. 2. ..02 2.0.6.0. 05 26: 18 4.32 Si al
lapathifolium, nodding smartweed............... 10 0.10 0.08
pensylvanicum, large-seeded smartweed........... 5 0.02 0.02
Other Polygonum.. 3 t Hee
Echinochloa crusgalli, wild millet. 10 3.30 2.50
Digitaria
Sanguinalis, crab-grass. . 1 2.50 1.89
ischaemum, smooth crab-grass. . Say As channu teas 1 0.30 0.23
Leersia oryzoides, PI CExCULO RASS eee rick cise teh 8 1.80 1.36
Scirpus
momaseuard-stem pulfush.. oc) a ME ds 2 2 1.30 0.98
fluviatilis, river-bulrush. . 2 0.25 0.19
validus, soft-stem bulrush. . ey ce 2 0.10 0.08
Potamogeton nodosus, longleaf pondweed. Ae eer & 6 1.60 1 21
Heteranthera dubia, mud- plantain. . Lape omc se 1 1.40 1 06
“coy ysse ro) ra een 5 a eg 47 6.73 5 09
Table 19.—The most important animal foods identified in 98 gadwall gizzards collected
in Illinois, 1938-1940.
OccuRRENCE VoLUME Per CENT OF
ANIMAL (NUMBER OF (Cusic Tora OrGANIC
G1zzARDs) CENTIMETERS) ConrTeENTS
TROTLANL ool NUNG UO EE Oe Baad AMO LOCO TA (BOO Ee a 3.69 2.79
NO MEWS CAP shells aie os cae: oehen «mas ae 1 t
ARTHROPODA
GnusTA Cram Ostracod ain, socicicincc ce nese ae: 1 t
INSECTA
Hemiptera, Corixa, water boatmen...........- 8 0.33 0.25
Coleoptera
Dytiscidae, diving beetles. 6 ery Bl conte dase Be
Scarabaeidae, Aphodius distinctus, ‘scarab —
beetles. . Des 1 0.02 0.02
Trichoptera, Hydroptilidae, “caddisflies. . oe = t tert
Lepidoptera larvae, moths. Seno ane 1 f
Diptera
Gotoatahs, Chironomidae larvae, midges. . 3 2.90 ZAG
Be ay cous oe 1 0.02 0 02
ARACHNIDA.. aie 1 0.10 0 08
ACARINA, Hydracarina, water mites. 1 t setae
NONFOOD, feathers. . 6 0.32 0.24
310 [ntrnors NaruraAt History Survey BULLETIN
vidual gizzards varied from a trace to 6
cc. and averaged 1.3 ce.
Thirty-four species of plants from the
gadwall gizzards were identified ; 0.88 per
cent of the plant material was too finely
ground to be recognized. The major por-
tion of the plant material consisted of the
stems and leaves of coontail and the en-
tire plants and particles of duckweed and
algae.
Plant groups contributing at least 1.0
per cent each to the organic contents of the
Vol. 27, Art. 4
tals, each under | mm. in size. Occasion-
ally, a stone up to 5 mm. (largest dimen-
sion) was found.
Shoveler
Spatula clypeata
Analyses of the contents of the duck giz-
zards collected in 1938, 1939, and 1940
indicated that, although animal foods are
more readily consumed by the shoveler
than by any other species of the dabbler
group, this duck is still very much a vege-
Table 20.—Shoveler gizzards collected in Illinois in approximately 2-week periods, 1938-1940.
NuMBER OF GIzzARDS
YEAR
OcTOBER NoveEMBER
16-31 1-15
joe te A a ge 19 1
TORO rec Nee 9 23
TAO ie nts cae eri ces Se es 1
LO ee ee 28 25
gadwall gizzards were coontail, algae,
marsh smartweed, wild millet, crab-grass,
rice cutgrass, longleaf pondweed, and mud
plantain, table 18. Coontail comprised
nearly three-fourths of the organic con-
tents. Moist-soil plant parts were found in
the gizzards of gadwalls that had appar-
ently visited flooded mud flats.
‘Twenty-six species of plants contributed
less than 1.0 per cent each to the organic
contents of the gadwall gizzards. Some of
these plants had been taken in large
amounts by only a few gadwalls and some
had been taken in small amounts by a com-
paratively large number of birds.
Animal Foods (2.79 Per Cent of Or-
ganic Contents ).—Animal organisms were
present in one-fourth of the gadwall giz-
zards. The animal contents of individual
gizzards ranged from a trace to 1.7 cc. and
averaged 0.14 cc. Only two groups of ani-
mals, the water boatmen and midge larvae,
made up as much as 0.1 per cent of the or-
ganic contents, table 19.
Inorganic Contents (74.04 Per Cent
of Total Contents).—Grit predominated
in the gross contents of the gadwall giz-
zards. In individual gizzards, grit ranged
in volume from a trace to 6.6 cc. and av-
eraged 3.85 cc. per gizzard. The grit was
mostly in the form of fine, white sand crys-
Tora.
NoveMBER DECEMBER
16-30 1-15
7 POM is rata gs 3 2 27
eh 9s op 2 34
7 2 62
tarian during the fall months in Illinois.
Because of their rather unsavory flavor,
shovelers are, by some hunters, allowed to
pass; or, if one of these ducks is killed,
usually it is left in the marsh. Because this
situation prevailed in 1938-1940, an ade-
quate sample of shoveler gizzards was difh-
cult to obtain, table 20. Only 3 of the 62
gizzards collected were obtained from
Mississippi River stations.
A shoveler gizzard was considered full
if its gross contents amounted to 6 cc. Con-
tents of individual gizzards ranged in vol-
ume from 0.7 to 7.0 cc. and averaged 3.3
cc. Only 4 of the 62 shoveler gizzards
were less than one-quarter full, and 16
were more than three-quarters full. Shoy-
elers represented by these gizzards ap-
peared to have obtained an adequate food
supply during their autumn stay in IIli-
nois.
The total contents of the shoveler giz-
zards amounted to 204.86 cc., of which
51.89 per cent (106.30 cc.) was inorganic
and 48.11 per cent (98.56 cc.) was or-
ganic. The supposition that the unsavory
flavor of the shoveler results from a diet
of animal food was not substantiated by
the present study. Plant structures formed
82.36 per cent and animal matter only
17.64 per cent of the organic material of
ge age Te ae ee
=
August, 1959 ANDERSON:
the shoveler gizzards collected, tables 21
and 22.
Plant Foods (82.36 Per Cent of Or-
ganic Contents).—The shoveler, more
than any other species of duck, skims food
from the surfaces of lake and marsh bot-
toms in very shallow water, much of it
less than an inch in depth. Because of this
Foop Hasitrs or Micratory Ducks 311
Nine plants, each represented by at least
1.0 per cent of the organic contents, pro-
vided the bulk of the feod in the shoveler
gizzards, table 21. Plants making up less
than 1.0 per cent each of the total organic
contents were not considered important
even though they appeared in large vol-
umes in a few gizzards. Their occurrence
Table 21.—The most important plant foods identified in 62 shoveler gizzards collected
in Illinois, 1938-1940.
Cyperus
| OccuRRENCE VOLUME Per CENT OF
PLANT (NUMBER OF (Cusic Tora Orcanic
GizzarpDs) CENTIMETERS) ConreENTS
MOUAL PLANT. fox cxccck 81.17 82.36
erythrorhizos, red-rooted nut-grass ... . 26 28.56 28.98
esculentus, chufa.. TER eke gee 4 7s 1.78
SUrigosus, nut-grass. An tatee ste 8 0.90 0.91
Cephalanthus occidentalis, buttonbush. 24 16.50 16.74
Zea mays, corn. 8 11.10 11.26
Ceratophyllum demersum, ‘coontail . 12 9.10 9°23
Echinochloa
BerECaE WALLIN EL Ase carte onan.» 4:2 Ge Kroes <3 1] 5312 eye WY,
suaiere Wy Alber Siimilletic,.. 3 oni, % aiec kha cen cts csi 1 0.20 0.20
Welumbo' lutea, American lotus. :......2.:..)....5.. 1 2.00 2.03
Polygonum
coccineum, marsh smartweed.. eee oth he: 33 1.18 1.20
pensylvanicum, large-seeded smartweed........... 4 0.30 0.30
lapathifolium, nodding smartweed. 9 Om2 0.12
punctatum, dotted smartweed . 4 0.10 0.10
Other Polygonum.. 11 t Se Sue
Eragrostis hypnoides, teal grass. . 1 1.60 1°62
Potamogeton
magosuslongleal pond weeds. 24.05. 0.265. 05s pes: 13 0.67 0.68
PEOMNGIAS, SAPO. PONAWEEE i... ose ct cate ee ene ew oe 3 0.40 0.41
SENS Re ONTO REIN Se k-< icle 210 cui v.00 Pa 2s Od Be sa 11 0.10 0.10
er ANE et cree teh Peskin shoe ia dub oure veto 45 1.47 1.49
habit, the shoveler ingests large numbers
of moist-soil plant seeds. The percentage
of these seeds was greater in the shoveler
gizzards collected in 1939 and 1940 than
in those collected in 1938 probably because
of the greater accessibility and availability
of the seeds on inundated mud flats in the
later years. The plant contents of indi-
vidual gizzards ranged from a trace to
6.3 cc. and averaged 1.3 cc.
Parts of plants representing 42 species
and some debris that could not be identi-
fied were found in the shoveler gizzards.
The bulk of the vegetative structures was
seeds and seed fragments of moist-soil
plants, some stems and leaves of coontail,
and seeds of the buttonbush, plant foods
similar to those consumed by the blue-
winged teal and the green-winged teal.
in only a few gizzards indicated a local
feeding condition.
Animal Foods (17.64 Per Cent of
Organic Contents).—Animal matter ap-
peared in 50 of the 62 shoveler gizzards,
but exclusively in only 6. The animal con-
tents of individual gizzards varied from a
trace to 2.4 cc.; most gizzards contained
less than 1 cc. each of animal structures.
Insect adults and larvae comprised 61.13
per cent and the Mollusca group 20.24
per cent of the volume of animal foods in
the shoveler gizzards, table 22.
Inorganic Contents (51.89 Per Cent
of Total Contents).—The volume of in-
organic material in individual shoveler giz-
zards ranged from 0.6 to 5.5 cc. and aver-
aged 1.71 cc. per gizzard. Most of the
gravel particles were less than 2 mm. in
w
—
bo
Ittrnois NarurAt History SurvEY BULLETIN
Vol. 27, Art. 4
Table 22.The most important animal foods identified in 62 shoveler gizzards collected
in Illinois, 1938-1940.
ee
ANIMAL
TOTAL, ANTMAL eS eR Sis ant Bie
BRYOZOA: statoblasts.ioac-o cree ene
MOLLUSCA
GasTROPODA, snails
Gyraulus parous......
Unidentified Gastropoda. .
PELEcYPODA, mussels
Pisidium. .
Unidentified Pelecypoda.
UniwentirfieD Mo.tusca.
ARTHROPODA
CRUSTACEA
Copepoda, vehicle Per pees ae ee hae
Ostracoda. .
INSECTA
Ephemeroptera, Hexagenia, mayflies...........
Hemiptera
Corixa, water boatmen..«......-22.-0-2s+5
Unidentified Hemiptera...............-+---
Coleoptera
Carabidae, ground beetles. .
Dytiscidae, diving beetles. .
Gyrinidae, whirligig beetles. .
Staphylinidae, rove beetles. .
Scarabaeidae, scarab beetles
Aphodius
distinctus..
femoralis. .
Trichoptera, Hydroptilidae cases, caddisflies. .
Diptera
oa raiiiiaed larvae, atte iy SR he eae
Unidentified Diptera...
Unidentified Insecta. . :
Acarina, Hydracarina, water mites.
NONFOOD, feathers. .
OccuRRENCE VOLUME Per CENT OF
(NuMBER OF (Cusic Tora. OrGanic
GizzarDs) CENTIMETERS) ConrTENTS
17.39 17.64
12 0.70 0.71
1 MR Se et
5 1.20 1.22
1 0.02 0.02
1 1.30 1:32
6 1.00 1.01
2 0.70 0.71
28 1.84 1.87
22 0.10 0.12
2 8.84 8.96
1 0.05 0.05
1 t ae
8 0.15 0.15
1 t tse
1 0.05 0.05
1 0.05 0.05
1 0.05 0.05
4 0.44 0.45
4 0.60 0.61
1 0.30 0.30
1 t. | 20 eee
4 t
1 t. °° 2) SS eee
size (largest dimension) ; a few stones
were as large as 5 mm.
Wood Duck
Aix sponsa
Because the wood duck was legally pro-
tected at the time of this study, only a few
gizzards of this species were available for
examination. A small sample was obtained
from confiscated birds. “Twenty-six giz-
zards were collected : 9 in the period Octo-
ber 15-31 and 17 in the period November
1-15, 1938, 1939, and 1940. Seven of the
gizzards were collected from Mississippi
River stations.
A wood duck gizzard was considered
full if the gross contents amounted to 9
cc. The contents of individual gizzards
ranged in volume from 2 to 10 cc. and av-
eraged 5.6 cc. per gizzard.
The gross contents of all wood duck
gizzards collected amounted to 171.38 cc.,
of which 29.00 per cent (49.70 cc.) was
grit and 71.00 per cent (121.68 cc.) was
organic substance. Of the organic mate-
rial, plant foods amounted to 99.85 per
cent and animal foods to only 0.15 per
cent, tables 23 and 24.
Plant Foods (99.85 Per Cent of Or-
ganic Contents).—The wood duck, as in-
dicated by the small sample of gizzards
collected, can be considered a vegetarian
during the fall months in Illinois. Plant
structures appeared in all the wood duck
gizzards collected. The plant contents of
individual gizzards ranged in volume from
0.8 to 9.6 cc. and averaged 4.7 cc. per giz-
zard.
Examination of the contents of the
wood duck gizzards indicated that during
a5
ee ae a
August, 1959
the autumn months the wood duck diet in
Illinois is similar to the mallard diet in
that corn is the major food. In the years
of this study, wood ducks were frequently
observed flying to and from mechanically
picked cornfields located close to the
wooded lakes and sloughs where these
ducks congregated. “Twenty-two plant
species were identified in the wood duck
gizzards collected, but only eight of these
were represented by at least 1.0 per cent
each of the organic contents, table 23.
ANDERSON: Foop Hasits or Micratory Ducks 313
Plants of secondary importance (those
that contributed less than 1.0 per cent each
to the total organic contents of the wood
duck gizzards) were not found in large
quantities in any of these gizzards. The
only plants in this group worthy of men-
tion were the lotus and the dogwood.
Animal Foods (0.15 Per Cent of Or-
ganic Contents).—This study indicated
that animal organisms are relatively unim-
portant to the wood duck during the fall
months in Illinois, table 24.
Table 23.—The most important plant foods identified in 26 wood duck gizzards collected
in Illinois, 1938-1940.
PLANT
TM QUBLG J ELLTURY ber Opes 8 ONDE PIA ACNE eric ete El RCI Ca ee eae ear
CIAL! URESISS C8 Nee bes wack cee POD ek OI ROE ECR ea
Quercus
palustris, pin oak..
Unidentified. .
Echinochloa cru sgalli, wild millet. .
Ceratophyllum
demersum, coontail.
Unidenti ified. .
Cephalanthus occidentalis, pia ect To wee
Potamogeton
nodosus, longleaf pondweed..............-..----
pectinatus, sago pondweed..................-...
ECE IQNOTY ZOLAES TICE CULZTASS.e 622+ o 5 a+ se ee ee oc
POR CHT ASO. ITOSt-QTAPC. oo6c: selies fen eee hae
Polygonum
coccineum, marsh smartweed.
hydropiperoides, mild d water-pepper Bs pene a
Other RU:
Other plants...
OccuRRENCE VOLUME Per CENT oF
(NuMBER OF (Cusic Tora OrGaAnic
GIzzARDs) CENTIMETERS) ConrTENTS
121.50 99 85
11 58.87 48.38
1 5.80 4.77
2. 12.40 10.19
1 14.70 12.08
2 2.80 2.30
1 5.10 4.19
6 5 Al 4.28
5 5.20 4.27
1 ie ne ote
3 4.60 3.78
2 2.50 2.05
7 1.09 0.90
1 0.40 0.33
7 t Sea en,
10 2.83 ESS
Table 24.—The most important animal foods identified in 26 wood duck gizzards collected
in Illinois, 1938-1940.
OccuRRENCE VOLUME Per Cent OF
ANIMAL (NuMBER OF (Cusic Tora OrGANIC
GizzARDs) CENTIMETERS) CONTENTS
VA ONB Aime TIN TIVEA Mice tec Loh don Miieaeht ab sidic wang chia, oko eee eae nk 0.18 0.15
ARTHROPODA, Insecta
Orthoptera, grasshoppers
Rhaphidophorinae. . 1 t noe
Unidentified Saltatoria. . 1 0.02 0.02
Hemiptera
Corixa, water boatmen.. Dy rt ee gece
Unidentified Hemiptera... 1 0.02 0.02
Coleoptera, Chrysomelidae, leaf beetles.
Diabrotica ee na howardi.. 1 0.02 0.02
Unidentified Coleoptera. . a 1 0.02 0.02
NONFOOD, feathers. . 1 0.10 0.08
UNIDENTIFIED ANIMAL.. 1 t eA
314 [turnois NaTrurAL History SurveEY BULLETIN
Vol. 27, Art. 4
Table 25.—The most important plant foods identified in 11 black duck gizzards collected
in Illinois, 1938-1940.
PLANT
TOTAL PLANT, ...
Ceratophyllum demersum, coontail..
Echinochloa crusgallt, wild millet... .. Dee es gO
Leersia oryzoides, rice cutgrass. .
Potamogeton
nodosus, longleaf peninree
pectinatus, sago Pye:
pusillus, small pondweed. .
Zea mays, corn.
Cephalanthus occidentalis, “buttonbush. .
Acnida altissima, water-hemp. .
Polygonum
coccineum, marsh smartweed. .
Other Polygonum Seg ee Ee et Penis leis
ELE aha rhe: gh A al UR AWE AR RR Me BeDM Ge ea rns
Inorganic Contents (29.00 Per Cent
of Total Contents).—Inorganic material,
present in all wood duck gizzards exam-
ined, ranged in volume from 0.4 to 5.6 cc.
in individual gizzards and averaged 1.9
cc. per gizzard. Most of the gravel par-
ticles were under 2 mm. in size (largest
dimension) ; however, a few stones ranged
in size up to 12 mm. In the gizzards in
which corn predominated as food, grit par-
ticles seldom exceeded 2 mm. in size.
Black Duck
Anas rubripes
Few gizzards labeled as those of black
ducks were examined. Co-operators sel-
dom distinguished between the common
mallard and the black duck or black mal-
OccuRRENCE VoLUME Per CENT OF
(NuMBER OF (Cusic Tora OrGANIC
GizzarDs) CENTIMETERS) ConTENTS
46.60 96.88
6 19.00 39.50
1 7.60 15.80
1 4.70 917
7 3.70 27269
1 0.70 1.46
1 0.05 0.10
1 3.30 6.86
3 2.70 5.61
1 2.70 5.61
5 1.60 3208
4 t peor ett ae
8 0.55 1.14
lard; for accuracy, the writer did not des-
ignate as black duck gizzards any he had
not collected personally. Eleven gizzards
known to be those of the black duck were
obtained in 1939 and 1940 in the period
October 15—November 15.
The capacity of a black duck gizzard
was considered to be 17 cc. None of the
black duck gizzards examined was com-
pletely full. The contents of individual
gizzards ranged in volume from 0.6 to
10.2 cc. and averaged 6.9 cc. per gizzard.
The gross contents of the black duck
gizzards amounted to 75.60 cc., of which
36.38 per cent (27.50 cc.) was grit and
63.62 per cent (48.10 cc.) was organic
matter. Plant parts comprised 96.88 per
cent of the foods, while animal structures
Table 26.—The most important animal foods identified in 11 black duck gizzards collected
in Illinois, 1938-1940.
ANIMAL
TOTAL ANIMAL...
MOLLUSCA
PR EERSPORNAANTINSEIS | 9), 35S oa ein BO ee ws
LINIDENTIFIED | MOLLUSCAy 00)... ood oelos ee ee
ARTHROPODA, Insecta
Ephemeroptera, Hexagenia, mayfiies. .
Coleoptera
Dytiscidae, diving beetles. .
Hydrophilidae, water scavenger ee
Trichoptera, caddisflies. .
OccuRRENCE VOLUME Per CENT OF
(NuMBER OF (CusBic Tora OrGAnic
G1zzArRDs) CENTIMETERS) ConTENTS
1.50 3.12
1 0.30 0.62
1 0.50 1.04
1 0.60 1.25
2 t Ree
1 0.10 0.21
1 t ae
August, 1959
amounted to 3.12 per cent, tables 25 and
26.
Plant Foods (96.88 Per Cent of Or-
ganic Contents).—Plant parts appeared
in all black duck gizzards collected. The
plant contents of individual gizzards
ranged in volume from 0.1 to 8.7 cc. and
averaged 4.2 cc. per gizzard. “Twenty
plant species were identified ; the nine that
were considered important constituted
95.63 per cent of all organic foods, table
Zo:
In general, the diet of the black duck
was similar to that of the common mal-
lard. Corn might have been more im-
portant on the list of foods of the black
duck if collections had been made later in
the fall and if a larger sample had been
taken.
Animal Foods (3.12 Per Cent of Or-
ganic Contents).—Only a few kinds of
animal organisms were represented in the
11 black duck gizzards, table 26.
Inorganic Contents (36.38 Per Cent
of Total Contents).—Gravel was present
in all black duck gizzards collected ; in in-
dividual gizzards, it ranged in volume
ANDERSON: Foop HaAsits or Micratory Ducks S15)
from a trace to 4.5 cc. Stones varied in
size from minute to 9 mm. (largest dimen-
sion) ; however, most inorganic particles
were less than 2 mm. in size.
Lesser Scaup
Aythya affinis
Lesser scaups are usually considered
omnivorous feeders, but this study indi-
cated their preference for animal foods
during the fall months in Illinois. Data
were obtained from 220 lesser scaup giz-
zards collected in the periods shown in
table 27. Of the total, 81 were from the
Mississippi River and 139 from the IIli-
nois River stations.
A lesser scaup gizzard was considered
full if its gross contents amounted to 5.7
cc. or more. The contents of individual
lesser scaup gizzards ranged in volume
from a trace to 10.5 cc. and averaged 2.86
cc. Approximately one-third of the giz-
zards were less than one-quarter full; four
of these were empty and showed indica-
tions of lead poisoning. Only 10 were
more than three-quarters full. Fatty tissue
surrounded most of the gizzards.
Table 27.—Lesser scaup gizzards collected in Illinois in approximately 2-week periods.
1938-1940.
NuMBER oF GIzzARDS
YEAR Tora.
OcToBER NoveEMBER NoveMBER DECEMBER
16-31 1-15 16-30 1-15
RR SS mre Mer ap MELO Bie pce A) Sarde Wiis anya 58 68 Pine oee we sire seaass 126
CRG). GS eae geen he| ae eee 19 37 10 66
WGA eR ee ao! 1 2 25 pe aren ree. 28
Wola etek OL 1 79 130 10 220
Table 28.—The most important plant foods identified in 220 lesser scaup gizzards col-
lected in Illinois, 1938-1940.
PLANT
LOU ANG TE) ea OTe SGC MG RS On COO AOE CN Ceara oe
Potamogeton
PECHialHas SAGO PONAWEEG ya. s 2s 6 1 sero
Badosuslongleat pondweed), 66.2 sec tes dea ss
Welosus leatye pond weeds sa 22.2 asietie tes ci-csaniele toe
PUSS. SMA PONG WEEG aan sa ears aoe ley eeral= om
Other Potamogeton.........
Ceratophyllum demersum, Puente has eke
ie tertal antsy eee ter teem at espns ee ea damavevece eke
OccuRRENCE VOLUME Per Cent oF
(NuMBER OF (Cusic Torat OrGANic
G1zzARDs) CENTIMETERS! ConTeENTS
39.49 9.65
32 4.29 1.05
58 3.41 0.83
12 3.00 0273
6 0.67 0.16
7 0.15 0.04
21 Omit 2.37
AAD 18.26 4.46
316 Inttrnois NatrurAL History SurvEY BULLETIN
Vol. 27, Art. 4
Table 29.—The most important animal foods identified in 220 lesser scaup gizzards col-
lected in Illinois, 1938-1940.
ANIMAL
TOTAL SAN LBs ic Pe TRAGER eRe eater ers | ech ede eevee ae
BRYOZOA statoblasts
MOLLUSCA
GasTROPODA, snails
USES MITES DONNIE 6 self isin, Steam mein seem SPO
FETE DI US CHO TNTES 28 5a rs ap sin) gic igre aks
Ga DEOING F550 se eR ee Me ae hee tats
Etoplas Sabra Pala | oo she Mele Sa, nap Oy 8
Amnicola
peracuta..
Unidentified ‘Amnicola. .
(Probythinella)
binnevana.
Unidentified ‘Amnicola a (Probythinella. efor
Flumnicola.
Somatogyrus
subglobosus......
a anaes Somatogyrus..
Pleurocera. .
Neritina..
Unidentified Gastropoda. .
PELECYPODA, mussels
Sphaeriidae
Pisidium. . , Fae
Musculium transversum.
Sphaerium
stamineum.
Unidentified S phaerium..
Unidentified Sphaeriidae. .
Unionidae, fresh-water dlains ss oe were
Unidentified Peletypoda..........0.. 2.05. 030% 26%
UNIDENTIFIED MOLLUSCA....<........--0000+ 20
ARTHROPODA
Crustacea
Caml gRSVIFsltS, CLAVTS Ms =). (oaks 83 Sena ene
INSECTA
Ephemeroptera, Hexagenia nymphs, mayfies .
Odonata, Anax junius, dragonflies.............
Hemiptera
Corixidae, Corixa, water boatmen...........
Gerridae, Gerris remigis, water striders.......
Goreidacy saash bugs. f2c050 uo ecenie saat oe
Unidentified Hemiptera: . 0c... 6... Se
Coleoptera
Carabidae, ground beetles. .
Dytiscidae, diving beetles. asain
Hydrophilidae, water scavenger beetles..... .
Scarabaeidae, cane ane
Curculionidae, snout beetles.
Trichoptera, Hydroptilidae cases, caddisflies. .
Diptera
Chironomidae larvae, naa
Anthomyiidae. . La ees
Unidentified Diptera...
Hymenoptera, Formicidae, ants.
ARACHNIDA
Araneae, spiders. .
Unidentified Arachnida...
NONFOOD, feathers.
ee ee ee
OccuRRENCE
(NuMBER OF
G1zzARDSs)
—m—npnone — eR
mNnNne
VoLUME Per Cent oF
(Cusic ToTat OrGANIC
CENTIMETERS) ConTENTS
369 87 90.35
ft TS eee eee:
t ears
4.90 1.20
29.00 7 08
4 35 1.06
0.50 0 12
23 30 5 69
23.25 5.68
1.50 0.37
2 80 0.68
0.30 0.07
0.80 0.20
3.40 0.83
2.50 0 61
80.88 19.76 3
12.70 3.10 .
13.10 3.20
0.40 0.10 :
71.60 17.49 x
34.30 8.38 4
10.59 2.59 5
1.14 0.28 a
31.11 7.60 £
:
&
0.10 0.02 i
4
13.56 3.31 x
0.70 0.17 ,
1.00 0.24
0 20 0.05
0.12 0.03
0.10 0.02
t ie
0 50 0.12
t.. Ol =e
0.10 0.02
t Re
t
0 20 0.05
0.29 0.07
t Aeon
0 08 0 02
t as. Ge
0 10 0 02
0 40 0 10
t eran
August, 1959
The gross contents of the 220 lesser
scaup gizzards amounted to 630.26 cc., of
which 35.05 per cent (220.90 cc.) was
grit and 64.95 per cent (409.36 cc.) was
organic material. Reflecting the appar-
ently carnivorous appetite of the lesser
scaups in I]linois, animal matter amounted
to 90.35 per cent of the organic foods,
while plant structures constituted only
9.65 per cent.
Plant Foods (9.65 Per Cent of Or-
ganic Contents) .—In Illinois, lesser scaup
ducks do much of their feeding on sub-
mergent vegetation at water depths of 3 to
ANDERSON: Foop Hasits or Micratory Ducks
EN ivi
important single plant, it was second in
importance to the pondweeds as a group.
Animal Foods (90.35 Per Cent of
Organic Contents).—Animal matter was
found in lesser scaup gizzards taken in all
collecting periods, but in greatest amounts
in those taken in the last 2 weeks of No-
vember. It was found in four-fifths of the
lesser scaup gizzards, exclusively in one-
fifth. The animal contents of individual
gizzards ranged in volume from a trace to
9.5 cc. and averaged 1.68 cc. per gizzard.
The principal animals represented in
the gizzards of lesser scaups, table 29,
Table 30.—Ring-necked duck gizzards collected in Illinois in approximately 2-week pe-
riods, 1938-1940.
NuMBER OF GiIzzaRDS
YEAR oe
OcroBER NOVEMBER NovEMBER DeEcEMBER
16-31 115 16-30 UUs
MOS Brers oche echoes 2s hers 2 52 50 y warts 104
NOS Ore ear kc ee nes 4 6 3 3 16
IGT he ee nee ene 6 58 53 i 120
*In this year, no ring-necked ducks were found among the ducks bagged and used for collection material.
5 feet and on mollusks and other animals
at depths up to 15 feet.
Plant structures were found in 140 of
the 220 lesser scaup gizzards collected.
Only 13.33 per cent of the organic con-
tents of the gizzards collected in 1938 con-
sisted of plant material. Comparable fig-
ures were 16.51 per cent for 1939 and
42.50 per cent for 1940; stable water con-
ditions in 1940 resulted in a marked in-
crease in submergent plant beds (Bell-
rose 1941:249-50, 252).
Plant material ranged in volume from
a trace to 3.7 cc. in individual lesser scaup
gizzards and averaged 0.18 cc. per giz-
zard. The bulk of the plant material was
composed of seeds and seed fragments of
several submergent plants and the stems
and leaves of coontail.
In all, 38 plant species were identified
in the gizzards of lesser scaups; however,
only a few of these were represented by at
least 0.5 per cent each of the organic diet,
table 28. Three species of pondweed con-
tributed a large volume of plant material
and occurred in a large number of giz-
zards. Although coontail was the most
were from the Mollusca phylum, which
accounted for 95.28 per cent of the animal
foods. Snails contributed 47.98 per cent
of the animal material and the bivalves
38.89 per cent. Shells of the brackish
water snail (Neritina) occurred in two
gizzards. The snails of this genus appar-
ently were ingested on the wintering
grounds and the shells retained in the giz-
zards through the breeding season. Most
aquatic insects in the gizzards were adult
mayflies or larvae. No fish fragments were
found.
Inorganic Contents (35.05 Per Cent
of Total Contents).—No attempt was
made to segregate gravel from calcareous
shell material in the lesser scaup gizzards;
both materials act as grinding agents.
Gravel was present in all of the gizzards;
individual particles ranged from minute
to 11 mm. in size (largest dimension).
Ring-Necked Duck
Aythya collaris
Although ring-necked ducks are excel-
lent divers and can obtain food at consid-
erable depths, they prefer shallow waters,
318 Ittrnois NaturAL History Survey BULLETIN
marshes, and sloughs. Of the 120 ring-
necked duck gizzards collected, table 30,
7 were from the Mississippi River region
and 113 from the Illinois River valley.
A ring-necked duck gizzard was con-
sidered full if the gross contents amounted
to 8.5 cc. or more. The contents of indi-
vidual gizzards ranged in volume from 0.4
to 11.0 cc. and averaged 3.7 cc. per giz-
zard. Most of the gizzards were sur-
rounded by heavy fatty tissue.
The gross contents of the 120 gizzards
of ring-necks amounted to 445.65 cc., of
which 41.31 per cent (184.10 cc.) was
grit and 58.69 per cent (261.55 cc.) was
organic material. Plants comprised 65.93
per cent of the organic foods, and animal
matter made up 34.07 per cent, tables 31
and 32.
Plant Foods (65.93 Per Cent of Or-
ganic Contents).—Plant structures were
present in nearly all the ring-necked duck
Vol. 27, Art. 4
gizzards. The plant contents of individual
gizzards varied from a trace to 9.1 cc. and
averaged 1.44 cc. per gizzard. Most of
the gizzards contained less than 2 cc. of
plant material each; the few with more
than 2 cc. contained plant material exclu-
sively. Plant material in the gizzards of
ring-necked ducks increased from 64.10
per cent of organic contents in 1938 to
75.20 per cent in 1939, paralleling the in-
crease in duck food plants in Illinois River
valley lakes (Bellrose 1941:249-53).
Although the gizzards of ring-necks
contained some unidentifiable plant debris,
44 species of submergent, emergent, and
moist-soil plants were recognized. Seeds
and seed fragments formed the bulk of the
structures; however, the stems and leaves
of coontail and the tubers of duck-potato
and chufa were present.
The 11 plants most important to the
ring-neck (plants that contributed 1.0 per
Table 31—The most important plant foods identified in 120 ring-necked duck gizzards
collected in Illinois, 1938-1940.
PLANT
DTDs, PAA Do oo tascio raze’ s awh viagra
Ceratophyllum demersum, coontail.....
PRAMAS COG Teoh Gh Leta yer e eats eh meee ae
Potamogeton
nodosus, longleaf pondweed...............2+2-5-
pert Tic! 98 ag ak pl ee eC ries
pusillus, small pondweed. .
foliosus, leafy pondweed..
gramineus, variable-leaf pondweed. .
praelongus, white-stem pondweed.
them Poramoccren: 1. ee eee oust
Polygonum
coccineum, marsh smartweed..................
lapathifolium, nodding smartweed.............
pensylvanicum, large-seeded smartweed...........
punctatum, dotted smartweed .................-
by dtopi per, water-pepper 26.16. 3 ods Poa he es
RRR ra AIE ck 8 4s ip Sao Rene Ste Soop Mee ee
Cyperus
erythrorhizos, red-rooted ae sored
esculentus, chufa...... es
Sagittaria latifolia, duck- -potato. .
Cephalanthus occidentalis, buttonbush. .
Scirpus
incsatiles rreerabairoehs ono. oo Go) Sa A oe
Bcuius, Nath-atety WTB. 14:2 f2. ios sce hee es
validus, soft-stem bulrush..................
ny RESET EET SI Te ee a em CSREES
Sparganium
eurycarpum, giant bur-reed..........
Eo EER RIO aA neg ee ais
MRC TREY tate Pot os id 2 sod delle tah
OccuRRENCE VOLUME Per Centr oF
(NuMBER OF (Cusic Tota OrGANIC
GiI7ZARDs) CENTIMETERS) ContTENTS
172.45 65.93
35 45.54 17.41
10 36.40 13.92
50 20.38 7 79
34 8.25 3.15
11 3.56 1 36
5 3.20 1.22
1 0.40 0 15
1 0.30 0.11
a 0.20 0 08
54 13.61 5 20
36 1.25 0 48
10 0.74 0 28
1 0.30 0 11
1 0.20 0 08
2. 0.10 0 04
13 7.85 3 00
2 0.10 0 04
1 6.70 256
19 3.78 1.45
15 S27 1.25
7 0.45 0.17
3) 0.02 0.01
1 0.03 0.01
8 1.13 0.43
10 2.44 0.93
67 1.95 4.68
August, 1959
cent or more each to the organic contents
of the gizzards representing this species,
table 31) totaled almost 60 per cent of
the volume of food in the gizzards.
Parts of the secondary food plants were
found in relatively large quantities in a
few gizzards of the ring-necks, but in most
gizzards only traces or small quantities
were noted.
Animal Foods (34.07 Per Cent of
Organic Contents).—Animal matter was
found in '80 ring-necked duck gizzards and
was represented in the four collecting pe-
riods. he animal contents of individual
gizzards varied from a trace to 7.6 cc. and
averaged ().73 cc. per gizzard. Only four
ANDERSON: Foop Hasits or Micratory Ducks
319
gizzards contained animal food exclusive-
ly.
Of the total animal material in the giz-
zards of the ring-necks, mollusks repre-
sented more than 70 per cent by volume;
more than half of the volume of mollusks
consisted of univalves, table 32. Adults
and larvae of insects constituted nearly 25
per cent of the volume of animal matter.
Bryozoan statoblasts, fish, crustaceans,
spiders, and water mites were present in
insignificant amounts.
Inorganic Contents (41.31 Per Cent
of Total Contents).—The volume of in-
organic material in the gizzards of the
ring-necks ranged from a trace to 7 cc. and
Table 32.—The most important animal foods identified in 120 ring-necked duck gizzards
collected in Illinois, 1938-1940.
OccuRRENCE VOLUME Per CENT OF
ANIMAL (NUMBER OF (Cusic Torat Orcanic
G1zzaRDs) CENTIMETERS) Contents
OMAR AINUVIAIG.. cos cbs 89.10 34.07
BRYOZOA statoblasts.. . 2 1.20 0.46
MOLLUSCA
ie snails
Stagnicola. . 2 5.10 1295
Physa.. Reeth a eK ect 1 0.20 0.08
Viviparus viviparus . sete: 1 0.20 0 08
Amnicola (Probythinella) binneyana. ae 3 2.40 0 92
Campeloma. . ASS eee k ie arate 4 3.70 1 41
Flumnicola..... 2 0.70 0.27
Somatogyrus ‘subglobosus. . 1 0.60 0.23
Pleurocera .... 1 0.20 0.08
Unidentified Gastropoda. . 14 20.29 7.76
PELecypopa, Sphaeriidae, mussels
Pisidium f Aaa 4 4.30 1.64
Musculium transversum. 3 5.20 199
Sphaerium.. ; 5 9.20 5) By
Uniwentiriep Mottusca.. 9 13.40 5.12
ARTHROPODA
Crustacea, Gammarus fasciatus, gammarid 1 t
INSECTA
Ephemeroptera, Hexagenia nymphs, mayflies. . 7 8.20 hal)
Hemiptera
Corixidae, Corixa, water boatmen. 17 2.36 0 90
Belastomatidae, Benacus nymphs, water bugs 1 0.12 0 05
Coleoptera
Carabidae, ground beetles. . 4 0.68 0.26
Dytiscidae, diving beetles. 6 0.06 0 02
Gyrinidae, whirligig beetles. . 1 0.05 0 02
Scarabaeidae, Aphodius distinctus, scarab
beetles. . rhea 1 0.60 0 23
Chrysomelidae, Chaetocnema, leaf beetles... .. 1 t yon
Unidentified Coleoptera. . : 1 t Sere
Trichoptera. . ee ee 6 0.10 0 04
Diptera, Chironomidae larvae, midges Ae ee ace 19 9°33 3257
Hymenoptera, Ichneumonidae, ichneumon flies... 1 f See
ARACHNIDA, Araneae, spiders. . 1 ft Lae
AcARINA, H ddracarina, water mites. 5 0.01 0 004
CHORDATA, Pisces. Se 1 t ete dink
NONFOOD, feathers... 5 0.90 0 34
320
averaged 1.53 cc. per gizzard. Gravel par-
ticles ranged in size from minute to 13
mm. (largest dimension). In 80 per cent
of the gizzards, grit particles seldom ex-
ceeded 3 mm. each. Apparently calcareous
shell material served as grit, for gravel
was absent from many gizzards.
Canvasback
Aythya valisineria
The canvasback is an omnivorous feeder
in Illinois, this study indicated. Many of ~
the canvasback gizzards collected (61 per
Ixtinoris NaturAL History Survey BULLETIN
Vol. 27, Art. 4
cent) contained only vegetable matter,
while a few (8 per cent) contained animal
matter exclusively. Because few canvas-
backs were killed in Illinois while field
work for this study was being done, only
a small number of canvasback gizzards
were collected. Of the 28 collected, 18
were obtained in 1938, 9 in 1939, and 1
in 1940; + of these were from the Mis-
sissippi River area. One gizzard was taken
in the period October 15-31, 13 in No-
vember 1-15, 13 in November 16-30, and
1 in December 1-15.
Table 33—The most important plant foods identified in 28 canvasback gizzards collected
in Illinois, 1938-1940.
DEER ING ga aie pis oe aa 4 Meena Ga RE Ce aes AE RTE
Potamogeton
nodosus, longleaf pondweed..................4..
WeCHNalus, SAPO DONAWEE s/c. 5 on ss Scoot Seek
pusiius, small: pond weed 2. cu suse optseiee so eeren
Jolsasus, leaty pondweed 6 225%,)% ss sss. fee
Saguiaria latifolia, duck-potatos. po. 8. 20 22 pes
Ceratophyllum demersum, coontail.....:............
ET So) Ee ett Be SEAR a a ea EEE tg SA
OccuRRENCE VOLUME Per CENT OF
(NuMBER OF (Cusic Tota OrGANIC
GizzarDs) CENTIMETERS) ConrTENTS
89.32 65.00
20 34.26 24.93
7 11.62 8.46
1 0.20 0.15
1 0.10 0.07
6 24.91 18.13
7 15.00 10.91
43 3:23 PHEEG)
Table 34.—The most important animal foods identified in 28 canvasback gizzards collected
in Illinois, 1938-1940.
ANIMAL
ER PION LIVE A Digests oo ES ed oo SO cea Wn ger tig Taaee
MOLLUSCA
GasTROPODA, snails
IBIS CLAM rte ae heed E.R Pe NR eae A
Flumnicola....
Unidentified Gastropoda.....................
PELECYPODA, mussels
Sphaerium......
Unidentified Pelecypoda......................
ARTHROPODA, Insecta
Ephemeroptera, Hexagenia nymphs, mayfiies....
Hemiptera, Corixa, water boatmen..............
Coleoptera
Carabidae, ground beetles....................
Dytiscidae, diving beetles....................
Dryopidae......
Diptera
Chironomidae larvae, midges......
Tabanidae, Tabanus larvae, horse Bees Wee
Unidentified Diptera larvae...................
CHORDATA, Pisces........
MANPOOD, feathers. 3500 pisces oy
Curculionidae, snout beetles..................
OccuRRENCE VOLUME Per CENT OF
(NUMBER OF (Cusic Tora. OrGANIC
GizzArRDs) CENTIMETERS) ConTENTS
48.10 35.00
1 2.30 U67
1 1.30 0.95
1 2.70 1.96
1 1.10 0.80
1 2.70 1.97
3 0.95 0.69
De 0.10 0.07
1 t . eee
] 0.05 0.04
1 t 5 ancy
1 0.20 0.14
5 32.00 21.28
1 0.30 0.20
1 4.30 2.86
1 t ee
1 0.10 0.07
ee eee ae rr ee eT
August, 1959
ANDERSON: Ioop Hasits oF Micratrory Ducks 321
Table 35.—The most important plant foods identified in 14 redhead gizzards collected in
Illinois, 1938.
Potamogeton
Other Potamogeton..
Polygonum
Scirpus
Ambrosia
OccuRRENCE VOLUME Per CENT OF
PLANT (NuMBER OF (Cusic ToTaL OrGANIC
G1zzaRDs) CENTIMETERS) CoNnTENTS
TOT ills TRIGA UN ELE DOs OO ne ee a ae eee Oe 40.30 77.93
nodosus, longleaf pondweed ... Pie ie SNe i! 17.03 B2E95
pectinatus, TESS Soa Gear ee 6 (0), 27 0.52
: 1 t ony:
Ceratophyllum demersum, coontail. . 4 7.40 14.31
Echinochloa crusgallt, wild millet. Sees ter 2 4 30 8.32
ree cote Ns ee ae. 1 2 60 5.03
coccineum, marsh smartweed. . 5 1.89 3.66
lapathifolium, nodding smartweed. Sas eet ener 4 OF35 0.68
pensylvanicum, large-seeded smartweed........... 2 0 25 0 48
punctatum, dotted smartweed................... I 0 10 0.19
PAGS SOttestemubulmushin eran a aes sees oA 5 0 80 eo
uviarleserivet=pulrush\sn aces cuteness cess iee es - 4 0.15 0.29
artemistifolia, common ragweed................. 1 t eer
Wnidentiiccea ria tee eta ice Secels 1 0.65 1.26
MIME tegeetee erst ts te ee ies eee 8 4.51 8.72
A canvasback gizzard was considered
full if the gross contents amounted to 14.5
cc. or more. The contents of individual
gizzards ranged in volume from 0.8 to
17.5 cc. and averaged 7.91 per gizzard.
In this study, 221.72 cc. of material was
obtained from the 28 canvasback gizzards;
of this material, 38.02 per cent (84.30 cc.)
was grit and 61.98 per cent (137.42 cc.)
was organic material. Plant structures
comprised 65.00 per cent and animal parts
35.00 per cent of the organic foods, tables
33 and 34.
Plant Foods (65.00 Per Cent of Or-
ganic Contents).—Plant structures were
found in nearly all the canvasback giz-
zards collected; the plant food contents of
individual gizzards ranged from 0.1 to
12.0 cc. and averaged 3.14 per gizzard.
Plants that furnished at least 1.0 per
cent each of the organic contents of the
canvasback gizzards were considered im-
portant, table 33. “These were longleaf
and sago pondweeds, duck-potato, and
coontail, which together amounted to
nearly two-thirds of the organic material.
Twenty plant species that individually
contributed less than 1.0 per cent of the
organic contents were considered of sec-
ondary importance. Some of these may
have been important locally but in most
canvasback gizzards they were found in
small quantities.
Animal Foods (35.00 Per Cent of
Organic Contents).—Animal parts were
found in two-fifths of the canvasback giz-
zards; the animal contents of individual
gizzards varied from a trace to 11.3 ce.
and averaged 1.72 cc. per gizzard. Ani-
mal forms considered important were those
that contributed at least 0.5 per cent each
to the organic contents, table 34.
Inorganic Contents (38.02 Per Cent
of Total Contents).—The volume of in-
organic material in individual gizzards of
the canvasback varied from 0.5 to 5.5 cc.
each. The quantity of gravel was smaller
in gizzards containing snail parts than in
others; evidently the shell material took
the place of stones. Gravel particles ranged
from minute to 11 mm. in size (largest di-
mension) ; most stones were no larger
than 2 mm.
Redhead
Aythya americana
Fourteen gizzards of the redhead duck
were collected, all in the period November
1-15, 1938. Data from this small sample
have limited value.
The capacity of a redhead gizzard was
considered to be 14 cc.; however, none of
w
bo
lo
ltniNois NATURAL History SuRVEY BULLETIN
Table 36.—The most important animal foods identified in 14 redhead gizzards collected in
Illinois, 1938.
ANIMAL
TOTAL ANTAL Sai eR eR es ne
BRYOZOA statoblastec cee 0 eae Morse
ARTHROPODA
INSECTA
Ephemeroptera, Hexagenia, mayflies ..........
Hemiptera, Corixa, water boatmen.
Coleoptera, Dee tiscidae, diving beetles. .
Trichoptera.. shavers halen
Lepidoptera. .
Diptera, Chironomidae larvae, ‘midges. .
ARACHNIDA
Argiopoideaspiderss:s. .iscocj nee eer ere oie he
Unidentified. Arachnida... -)..2:2 554622525 ed oie
Acarina, Hydracarina, water mites..
NONHOOD! featheeic.. ae, ae ee
the gizzards collected contained this vol-
ume of material. Gross contents of indi-
vidual gizzards ranged from 3.2 to 10.0
cc. each and averaged 6.47 cc. per gizzard.
Of the 90.61 cc. of material, 42.93 per
cent (38.90 cc.) was grit and 57.07 per
cent (51.71 cc.) was organic substance.
Plants contributed 77.93 per cent of the
organic contents and animal organisms
22.07 per cent, tables 35 and 36.
Plant Foods (77.93 Per Cent of Or-
ganic Contents).—Plant structures were
found in 13 of the 14 redhead gizzards;
the plant contents of individual gizzards
ranged in volume from 0.8 to 6.9 cc. and
averaged 3.1 cc. per gizzard. The bulk of
the material consisted of longleaf pond-
weed seeds. Nineteen food plants were
identified ; six species contributed at least
1.0 per cent each to the organic contents,
table 35. Seeds of the alkali bulrush, a
western species not indigenous to Illinois,
were found in one gizzard.
Animal Foods (22.07 Per Cent of
Organic Contents).—Animal organisms
were present in 12 of the 14 redhead giz-
zards; the animal matter in individual giz-
zards ranged from a trace to 4.3 cc.
Midges were found in six of the gizzards,
table 36.
Inorganic Contents (42.93 Per Cent
of Total Contents).—The grit contents
of individual gizzards of the redhead
ranged from 0.9 to 4.8 cc. and averaged
2.78 cc. per gizzard. A major portion of
OccuRRENCE VOLUME Per CENT OF
(NUMBER OF (Cusic Torat Orcanic
GizzarDs) CENTIMETERS ConTeNnTs
11.41 22.07
l C
1 0.30 0.58
1 0.01 0.02
1 t Ry
2 1.50 2.90
1 0.09 0.17
6 9.50 18.37
1 0.01 0.02
1 t piace
1 t. >» Ae eee
1 t
the inorganic material consisted of quartz
particles varying in size from minute to 2
mm. (largest dimension) ; the material in-
cluded an occasional stone up to 11 mm.
Ruddy Duck
Oxyura jamaicensis
Only five ruddy duck gizzards were col-
lected for this study. All were obtained
between October 15 and November 15,
1939 and 1940. The gross contents of
these gizzards amounted to 16.6 cc., of
which 63.86 per cent (10.6 cc.) was grit
and 36.14 per cent (6.0 cc.) was organic
material. Of the organic food, plant struc-
tures amounted to 23.33 per cent and ani-
mal matter to 76.67 per cent.
Plant Foods (23.33 Per Cent of Or-
ganic Contents).—Plant parts appeared
in three of the five ruddy duck gizzards;
only a trace in two and 1.4 cc. in the other.
Four species of plants were represented:
coontail made up almost 100 per cent of
the bulk; longleaf pondweed, leafy pond-
weed, and wild millet appeared as traces.
Animal Foods (76.67 Per Cent of
Organic Contents).—Animal structures
were found in all five ruddy duck giz-
zards. The animal contents of individual
gizzards ranged from a trace to 1.7 cc.
Midge larvae comprised almost 100 per
cent of the animal matter; water boatmen
and water beetles appeared as traces.
Inorganic Contents (63.86 Per Cent
of Total Contents).—Gravel made up
Vol. 27, Art. 4
id
August, 1959
nearly two-thirds of the gross contents of
the ruddy duck gizzards. The inorganic
contents of individual gizzards ranged
from 1.2 to 4.0 cc. and averaged 2.1 cc.
Most gravel particles were each smaller
than 2 mm. (largest dimension).
Common Goldeneye
Bucephala clangula
Only three goldeneye gizzards were ob-
tained for this study, all of them in the
period November 14-30, 1938. The total
gross contents amounted to 2.6 cc., of
which 50.00 per cent (1.3 cc.) was grit
and 50.00 per cent (1.3 cc.) was organic
material. Longleaf pondweed, which con-
stituted 15.38 per cent of the organic con-
tents, was the only important plant species
represented, while mayfly nymphs, which
constituted 84.62 per cent of the organic
contents, was the only animal food.
Greater Scaup
Aythya marila
The gizzard of one greater scaup was
collected on November 16, 1940. It con-
tained grit material amounting to 1.0 cc.
and no animal or plant structures.
Oldsquaw
Clangula hyemalis
The gizzard of one oldsquaw duck was
obtained in the fall of 1940. It contained
ANDERSON: Foop Hasits or Micratory Ducks
323
2.7 cc. of material, of which 11.11 per
cent (0.3 cc.) was grit and 88.89 per cent
(2.4 cc.) consisted of plant and animal
matter. Coontail made up the entire plant
contents (41.67 per cent of the organic
material), while fish bones, midges, and
snails made up the animal contents (58.33
per cent of the organic material).
PLANT FOODS
Data derived from analyses of the con-
tents of waterfowl gizzards collected in
Illinois in the autumns of 1938, 1939, and
1940 were used in making evaluations of
the most important plants utilized as food
by waterfowl migrating through the state.
Although no completely satisfactory
evaluations of the importance of various
kinds of food plants are possible, a rough
evaluation of each of the most important
kinds was given by an index figure ob-
tained by multiplying the number of giz-
zards in which the kind of plant was found
(occurrences) by the actual figure indi-
cating the percentage it constituted of the
total plant volume (for example, for Zea
mays, multiplying 1,445 by 39.36, figures
derived from table 38).
The nineteen species of plants that were
most utilized by ducks in their southward
migrations through Illinois are listed in
table 37. These plants were the favored
Table 37.—Occurrence-percentage index ratings of plant foods identified in duck gizzards
collected along the Illinois River, Ottawa to Florence (4,505 gizzards), and along the Missis-
sippi River, Rock Island to Quincy (472 gizzards), 1938-1940 (derived from table 38).
PLANT
INDEX
NuMBER
Zea mays, corn. be I ences
Leersia oryzoides, rice cutgrass. . J
Polygonum coccineum, marsh smartweed..
Ceratophyllum demersum, coontail..
Echinochloa crusgalli, wild millet.......
Potamogeton nodosus, longleaf pondweed. .
Cyperus erythrorhizos, red-rooted nut- -grass..
Acnida altissima, water-hemp..
Polygonum lapathifolium, nodding smartweed..
Cephalanthus occidentalis, buttonbush.
Polygonum pensylvanicum, nee seeded ae Re tor tee
Cyperus strigosus, nut-grass..
Cyperus esculentus, chufa..
Echinochloa walteri, Walter’: S ‘millet. .
Potamogeton pectinatus, sago pondweed.
LEE lee aaa eae
Scirpus fluviatilis, river-bulrush. .
Eragrostis hypnoides, teal grass. :
Sparganium eurycarpum, giant bur-reed. .
324 Intrnois NaturAL History Survey BULLETIN Vol. 27, Art. 4
Table 38.—Plant foods of ducks taken along the Illinois River, Ottawa to Florence (4,505
gizzards), and along the Mississippi River, Rock Island to Quincy (472 gizzards), 1938-1940.
I-tinois RIver Mississippi River
Occur- Occur-
PLANT rence ‘ean . er a rence (ee ak inl
T
ey Centi- | Organic eer Centi- | Organic
oe sy; meters) | Contents si dey meters) | Contents
TOTAL PLAN Te oy cident tate ieee 94.82 ).........|1 ,S4eaee 90.36
Zea mays, corn. Sc ae 1,262 |6,429.05 35.38 183 | 883.20 59.44
Leersia ory zoides, | rice cutgrass. . eats 880 |2,339.58 12.87 41 52.62 3.54
Ceratophyllum demersum, coontail. . 795: 151.63 9.64 14 24.10 1.62
Echinochloa
crusgalli, wild millet.............. 669 |1,165.32 6.41 46 30.22 2.03
walteri, Walter’s millet........... 243 | 410.67 2.26: |... + 2 soins |. «oe sen
PlereteestAhe rds Soin: apkacre tee snes cine 2 1.40 0.01
Cyperus
erythrorhizos, red-rooted Shs coer 613 | 683.11 3.76 + 6.90 0.46
Sirignsls (HUE-BTASS . S25! Le ae 378° | 289.13 159 6 3.60 0.24
SSCUIENELS CUA B62. oe alee ato 384 | 267.42 1.47 1 t ;
ferax..... ree ene apis Reser 3 0.20 t 4 0.70 0.05
Unidentified. . SERS eee as 20 47.78 0.26 Bers
Polygonum
coccineum, marsh smartweed...... 1,995 | 760.02 4.18 17 1.32 0.09
lapathifolium, nodding smartweed.. 1,028 | 161.01 0.89 117 19.65 1 ae
pensylvanicum, large-seeded smart-
ska = * Cee ete 480 | 141.63 0.78 119 56.19 3.78
hydropiperoides, mild water-pepper. 219 82.32 0.45 6 0.40 0.03
punctatum, dotted smartweed..... 173 35.31 0.19 36 21.36 1.44
persicaria, lady’s thumb.......... 101 11. 71 0.06 15 6.25 0.42
Aydropiper, water-pepper. . 61 6.15 0.04 28 4.00 0.27
scandens, climbing false buckwheat 7 0.33 t 4 0.15 0.01
sagittatum, arrow-leaved tearthumb 2 0.20 t 1 0.40 0.03
amphibium, water lady’s thumb.. 1 0.05 t 3 0.02 t
aviculare, prostrate knotweed..... Re eee late ae eta ae mb oneear= 1 t
RIMGEMEHER Sc)25ts pa os Sik Sig Silt 15 Dedt 0.01 4 1.70 0.11
Potamogeton
nodosus, longleaf pondweed....... £5252" | 329065 1.81 22 5.40 0.36
pectinatus, sago oe Cala peer aie te 596 | 104.22 0.57 34 21.77 1.47
foliosus, leafy pondweed.......... 179 40.03 0.22 42 14.10 0.95
pusillus, small pondweed.......... 98 17.76 0.10 6 0.87 0.06
perfoliatus, thoroughwort pondweed 3 8.40 0.05 se es eee:
praclongus, white-stem pondweed. . 5 1.70 0.01 RE
amplifolins, \arge-leaved pondweed_ 2 0.11 t oats een
epthydrus, ribbon-leaf pondweed . 2 0.05 t 2 1.30 0.09
gramineus, variable-leaf Bae 2 Vong seal ics gall cnintae eetoen 1 0.40 0.03
Unidentified. . me Seas: 44 2.04 0.01 § 0.20 0.01
Acnida altissima, \ w jater-hemp. nia toe 691 | 494.59 2292 4 0.32 0.02
Sagittaria
latifolia, oe ea aOR a. ere 156 | 254.41 1.40 11 3.44 0.23
CUCM, WADALO’ cas 333s lee as 1 0.50 t Soe Re ae
Unidentified. . 2 1.31 0.01. |... a... Sa] cee
Cephalanthus occidentalis, buttonbush 660 | 252.88 1.39 30 4.77 0.32
Eragrostis
hy pnoides, teal aes soe Paige 114 | 188.71 LOA SH tupac
Unidentified. . RE ye ae teas 2 0.40 t ine (a bua pov flaca as. nee eer
Triticum aestivum, PRA IIS GPs 46 | 169.90 0.93 1 4.40 0.30
Lemna
minor, lesser duckweed........... 152 95291 0.53 8 8.30 0.56
RMIIPSCIC cist os So ns a Sia sce 2 3.20 0.02: |. eccd ss «5 [ys pe ae
August, 1959
Table 38.—Continued.
PLANT
Sparganium
eurycarpum, giant bur-reed........
Wnirdentincdeeens Sc Scab ee Sasenne
Scirpus
Winviatilis, river-bulrush.......... .
atrovirens, green bulrush..... ....
acutus, hard-stem bulrush.........
validus, soft-stem bulrush.........
paludosus, alkali bulrush..........
americanus, American bulrush. .. . .
Unidentified...
Algae.
elimi ‘lutea, American lotus...
Quercus
alba, white oak.
palustris, pin oak. Ae
Unidentified acorns.........
ean Te dae common buck-
wheat. . :
Rumex
masimus, pale dock .......+.5.
mectosciia, field’sorrel.......2. +». +
Winidentifiedas:.-.22.c%.2-.<54:-
Bidens
frondosa, poeeeoe ticks.
Unidentified. . ee
Ambrosia
artemisitfolia, common ragweed... .
trifida, great ragweed . fe:
psilostachya, western ragweed ae ae
Unidentified . Te eyes
Najas
guadalupensis, southern naiad ...
flexilis, northern naiad.... . ....
Winidentificdien.. 6 4.. 2.1.0.5
Eleocharis
palustris, common spike-rush. ..
obtusa, blunt spike-rush... ... .
parvula, dwarf spike-rush ......
Unidentified. .
Heteranthera dubia, mud- plantain. .
Funcus, bog-rush. . eee
Bark, roots, and wood. .
Ranunculu: , buttercup. .
Nymphaea tuberosa, yellow. water- lily
Chenopodium
album, \amb’s-quarters. .
Unidentified. .
Alisma subcordatum, water- plantain.
Salix, willow. . Pe ce
Cornus, dogwood. .
Lippia "lanceolata, fog-fruit..
Vigna sinensis, cow-pea..
Myriophyllum
Bophylen, water-milfoil .
Unidentified. . ifs
Ittinois River
ANDERSON: Foop Hasits or Micratrory Ducks
W
bo
nn
Misstssipp1 RIveR
Occur- Volume
rence, (Cubic
(Number Ce :
of Giz- Sabi
ae meters)
286 60.36
134 31.74
464 47.97
3 9.50
171 8.90
i 3.58
5 3.30
Tal Nea)
45 58.29
43 55.60
3) 16.90
sg) 3840
8 37.40
62 27.05
1 t
10 0.08
11 20.68
29 1.95
28 7.94
20 Je55
85 1.07
1 0.65
18 14.35
16 1.10
3 1.30
69 8.44
99 4.22
1 2.00
8 t
5 14.30
24 12.58
8 8.15
7 8.10
10 6.58
1? 6.41
1 t
1 6.20
16 (5. 117/
75 6.04
219 5.60
1 5.20
10 0.50
60 4.23
Per Cent
of
Organic
Contents
mW
os: ossss ss
oooodw
NNMnMN ~sIW
Wo:
Noe:
os
eS -1G9
Oo —_—
Occur-
rence
(Number
— .
Ne:
DSi we wwe
ok!
co 00 tO
i)
ey
- OONn: -
w-
Per Cent
of
Organic
Contents
326 Intrnors Narurat History Survey BULLETIN Vol. 27, Art. 4
Table 38.—Continued.
I.trnors River Mississippt River
Pass neg Volume | Per Cent Se ca Volume | Per Cent
(Cubic of (Cubic of
(Number A -_ | (Number : :
a Centi- | Organic . Centi- | Organic
of Giz- of Giz-
: meters) | Contents meters) | Contents
zards) zards)
Spartina pectinata, prairie cord-grass . 2 4.20 0.02
Carex
rostrata, beaked sere as sk ones eens cr ea 1 0.10 0.01
Unidentified. . 33 4.13 0.02 9 3820 0.22
Lophotocarpus.. 12 4.10 0.02 jee ae
[pomea hederacea, ‘ivy-leaved morning-
glory. 35 4.04 0.02 1 t' fea eee
Zannichellia palustris, horned d pond
weed. . at 5 3.60 0.02 3 ae Mee
Sida spinosa, prickly s sida. . ne 34 3.56 0.02 5 0.20 0.01
Gramineae. . oe 3.30 ().02 areas oe
Paspalum
ciliatifolium, ciliate-leaved
Peak can Set fe «ep Reeve 2 3/25 0.02 1 1.50 0.10
Rien ited 2.25 okies eines oe 1 t Age Ree
Vitis
cordifolia, frost Brapes: 4 0.25 t 2 2.50 0.17
Unidentified. . ee 56 2.82 0.02 10 17.72 1.19
Potentilla, cinquefoil. . 1 3.00 0.02 sages a
Digitaria
sanguinalis, crab-grass.. Bae 3 2.50 0.01 2 0.30 0.02
ischaemum, smooth crab- _grass. Ra 4 0.30 t 2 0.50 0.03
Anacharis canadensis, waterweed..... 1 2.10 0.01 Sra eee Rete
Panicum
dichotomifiorum, fall panic-grass.. . . 38 1.90 0.01 7 4.90 0.33
capillare, old-witch grass.......... 18 0.11 2 s:| |S aaheeee
Beatenavyiciccs ioe ie see 1 1.50 0.01 ae
Verbena
hastata, blue vervain. 1 0.80 t 52 Sra ae
Unidentified. . 4 0.05 t ee SN
Abutilon theophrasti, velvet-leaf . 37 0.83 t 1 0.03 t
Hibiscus
militaris, scarlet rose-mallow...... 2B 0.50 t 2 t
Unidentified.... 5 0.06 t on
Setaria
italica, German millet............ 3 6.40 0.04 Rae Be:
glauca, yellow foxtail............. 17 0.50 t 5 0.10 0.01
Drid¢ussoreen, toxXtalles i...) teas 1 t 1 t eae
Celtis occidentalis, pack Bein errr 1 0.50 t ‘aa
Compositae.. Shane tots 1 0.40 t
Crataegus, hawthorn... 2 0.30 IE
Solanum, nightshade. . ase 1 0.30 t
EAE 5 ao ena 1 0.30 t
Rhus
glabra, smooth sumac. 18 0.18 t ff 0.20 0.01
radicans, poison ivy. 6 0.10 1 t | ange
Unidentified. 1 t 1 ee
Phaseolus, wild bean. . 1 0.20 t Pa
Strophostyles
helvola, trailing wild bean. . 1 0.10 t
Unidentified. . se 2 t
Pontederia cordata, heart-shaped |
pickerelweed...... ye re? 2 0.08 t wii ae
Cladium mariscoides, twig-rush. dec era 16 0.07 t 2 0.04 t
Cassia fasciculata, partridge-pea Deer: 1 0.03 t SAAN Boas -
Amaranthus
retroflexus, green amaranth........ 1 t
|iisire [riot (2 ee oe see 1 0.01 t
August, 1959 ANDERSON: |*oop Hasits or Micratory Ducks 327
Table 38.—Continued.
I-tino1s River Mississippi River
Bee Sa Volume Per Cent ares Volume Per Cent
(Number (Cubic = (Number (Cubic of |
6 Gin: Centi- | Organic |*o¢ Gg, | Centi- | Organic
ade) meters) | Contents aed meters) | Contents
Rubus
Alagellaris, northern eek eee 4 0.02 t aie
Unidentified. . 2 a eee 5 t ay oe ae
Ammannia coccinea, ~tooth- cup. nou See eee | Meni + 3.10 0.21
Avena sativa, oats. oe 1 t sae arAaes ie
Convolvulus arvensis, ' field- bindweed. | ee ce Noa 1 t Soa
Cuscuta, dodder . Ae eae, care 7 t 3 0.10 0.01
Diodia teres, buttonweed. . Da ere 1 t ae ane en
Geum, avens. ¥ Recs Noe te 1 t
Phytolacca americana, common
pokeweed. 5 t 1 t Neier
Portulaca, purslane. . sid Bet ake | pre Ay gs (nee ae 1 2.30 0.15
Rosa, rose. ees oa aoe 3 t Bae Lust ote octet
Sorghum vulgare, sorghum. . oe Baie 1 1.40 0.09
Prunus, cherry. . 2 t ahs Sti
Symphoricarpos orbiculatus, coral-
INS VAP Re gr Ny STR ANT at cis ail is Thneneloees ill esatageeer are 5 1.10 0.07
Trifolium, epee oe 1 t oh eg Sere Sea alien ee cee
Unidentified plant. . 73 63.68 0.35 23 18.09 122
ones in each of the 3 years of this study;
from year to year the relative positions of
some of them changed within the group as
a result of changes in abundance or acces-
sibility.
Food plants favored by the various spe-
cies of ducks differed with the feeding hab-
itats of the birds. Foods utilized by ducks
of the teal size were mainly from small-
seeded plants, while those utilized by the
mallard were principally from corn and
from large-seeded native wild plants. The
puddlers fed principally on emergent and
moist-soil plants, while the divers fed
largely on submergent plants. “here were
exceptions in each waterfowl group, how-
ever, such as the gadwall and the baldpate,
which fed primarily on a submergent
plant, coontail, and the ring-necked duck
and the redhead, which fed extensively on
emergent plants.
Of the plants represented in the giz-
zards collected for this study, 95 native
wild plants and + domestic plants were
identified to species, table 38. The 19 im-
portant species listed in table 37 and dis-
cussed in the following pages constituted
92.91 per cent of the total plant material.
Analyses of gizzard contents showed that
the plants increased or decreased in use-
fulness to ducks during the fall season as
weather conditions and water levels var-
ied.
Corn
Zea mays
Corn was the most important food both
in volume and in number of duck gizzards
in which it was found (occurrences), table
38. It comprised 37.20 per cent of all or-
ganic foods in the gizzards, primarily be-
cause it was the staple food of the mallard,
which made up over 50 per cent of the
duck flight. It appeared in 1,445 gizzards,
of which 86.92 per cent were mallard and
9.55 per cent were pintail. Of the 26
wood duck gizzards that were collected,
11 contained corn.
Use of this grain depended largely upon
the time of corn harvest. In 1939, corn
ripened early, and harvesting was well
along by October 15; in that year, mal-
lard gizzards collected early in the season
were gorged with kernels of waste corn.
However, in 1940, corn harvesting did
not commence until late in October or
early November, and native wild foods
appeared in gizzards in large volumes until
the waste corn was available. The volume
of corn increased from October 16 to De-
328 InuiNots NarurAL History Survey BULLETIN
cember 15, even though the number of
duck gizzards containing corn decreased.
Rice Cutgrass
Leersia oryzoides
Rice cutgrass, fig. 6, was shown by
this study, tables 37 and 38, to be the
most important wild native food plant in
Illinois during the autumn. This plant
was spotty in distribution, but apparently
wherever the seeds, rootstocks, and tender
shoots were accessible they were avidly
consumed. Pintails and mallards were the
most important consumers. As many as
2,000 seeds were taken from a single pin-
tail gizzard.
Plant structures of rice cutgrass, found
in 921 duck gizzards, comprised 12.17 per
cent of the entire organic contents of the
4,977 gizzards examined. Rice cutgrass
provided a good, staple food throughout
the fall months. The volume of rice cut-
grass structures in gizzards decreased
gradually from 16.83 per cent of the plant
Fig. 6.—Rice cutgrass (Lecrsia oryzoides), known also as saw-grass. This plant grows on
moist soil in shallow water. Ducks feed on the seeds and rootstocks.
Vol. 27, Art. 4
ewrr. ee
August, 1959
foods in late October to 11.75 per cent in
early December.
Marsh Smartweed
Polygonum coccineum
Marsh smartweed, fig. 7, ranked fourth
among wild native food plants in percent-
age of total organic contents of the duck
gizzards examined, table 38; it was second
among wild plants and third among all
plants in the occurrence-percentage index
rating, table 37. In the region and years
of this study it was an abundant plant, but
ANDERSON: Foop Hasits oF Micratory Ducks 329
in much of the region it was low in seed
production. In a few areas where water
level conditions were favorable, it pro-
duced an abundance of seeds in 1938 and
1939. Because of sporadic seed production
(Low & Bellrose 1944:14), this plant
varied from year to year in usefulness as
a source of duck food. All important spe-
cies of ducks fed on the seeds, but these
seeds seldom made up the bulk of the plant
food for any one duck.
Marsh smartweed seeds were found ina
large number of gizzards (2,012), but
Fig. 7—Marsh smartweed (Polygonum coccineum), sometimes called redtop because of its
pink-red blossoms. When it grows in water 6 to 18 inches deep it produces seed that rates high
as duck food.
330 Iturnors NatrurAL History Survey BULLETIN
=
never in large quantities. Because the
seeds drop early in the fall, this smartweed
is considered a good early season source of
food. In October, this plant represented
5.50 per cent of the plant food but, by
early December, only 1.85 per cent.
Marsh smartweed rated as an important
baldpate and gadwall were the most avid
feeders. During October, when waste
corn was scarce, mallards fed extensively
on coontail.
Coontail structures, which were found
in 809 gizzards, represented 9.03 per cent
of the total organic contents of all giz-
_ a —
— ie Saale
ein sty —oeere ss)
Fig. 8.—Coontail or hornwort (Ceratophyllum demersum). A favorite food of baldpates,
gadwalls, and ring-necked ducks, it grows best in stable or semistable waters that are fairly
clear and protected from wave action. Ducks feed principally on the leaves and stems.
waterfowl food plant despite the relatively
small quantities of its seed ingested by in-
dividual birds.
Coontail
Ceratophyllum demersum
Coontail, fig. 8, which occurred com-
monly in all stable and semistable water
areas involved in the study, ranked second
among wild native food plants in percent-
age of the total organic contents of all duck
gizzards examined, table 38, but it rated
fourth in the occurrence-percentage index,
table 37. Seed production of coontail was
low in the years of this study; leaves and
stems were the principal structures found
in the gizzards. This study showed that
all species of ducks of which there was an
adequate sample fed upon this plant; the
zards. Analyses showed that utilization of
coontail rapidly decreased during the fall
season, from 16.84 per cent of the volume
of plant foods in October to 2.20 per cent
in December. Despite the decrease in vol-
ume, coontail appeared to be an important
source of food through most of the fall.
Wild Millet
Echinochloa crusgalli
Because some difficulty was experienced
in separating the seeds of wild millet from
the seeds of Japanese millet, Echinochloa
frumentacea, undoubtedly some _ seeds
classified as wild millet were those of the
Japanese species. However, in the years
in which gizzards were collected for this
study, the acreage of Japanese millet in
Illinois was comparatively small.
Vol. 27, Art. 4
August, 1959
Wild millet, fig. 9, ranked third among
wild native food plants in percentage of
the total organic contents of all duck giz-
zards examined, table 38. Although its
occurrence was spotty in the Illinois and
Mississippi river valleys in the years of
this study, it ranked fifth in the occur-
rence-percentage index, table 37. During
1939 and 1940, water level conditions in
some areas were very favorable for luxuri-
ant growth and heavy seed production of
millets (Bellrose 1941:253). Seeds of
the wild millet were found in the gizzards
of most ducks and were especially numer-
ous in those of pintails, mallards, and
green-winged teals. A few pintail gizzards
held as many as 1,000 seeds each, and the
craws another 3,500.
Wild millet seeds or other plant parts
appeared in 715 gizzards and constituted
ANDERSON: Foop Hasits oF Micratory Ducks 331
6.08 per cent of the total organic contents
of the gizzards examined. The heaviest
consumption of wild millet occurred in
October, when this plant represented
10.76 per cent of the plant foods in the
gizzards; the consumption decreased to
3.90 per cent by December, probably as a
result of a decline in availability of millet
seed and a shift by the mallard and the
pintail to a corn diet.
Because the seeds remained on the
plants until late fall, wild millet proved
to be an excellent source of food for ducks;
also, the rank stem growth provided pro-
tective cover.
Longleaf Pondweed
Potamogeton nodosus
The longleaf pondweed, fig. 10, is con-
sidered one of the good duck food plants
Fig. 9.—Wild millet (Echi-
nochloa crusgalli). Known
also as barnyard-grass, this
moist- soil plant produces
seeds that are consumed in
large quantities by mallards,
pintails, teals, and other
ducks. The inset shows wild
millet growing on a mud flat
from which water has re-
ceded. In 1939 and 1940,
water levels along the IIli-
nois River were especially
favorable for growth and
seed production of millets.
The millets provide cover as
well as food for ducks.
ae
w
bo
in many parts of the United States. In
Illinois, it was present in small amounts in
nearly all the river-bottom lakes in the
region and years involved in the present
study; usually it produced an abundance
of seed. In the gizzards of all important
species of waterfowl included in this re-
port, the seeds and occasionally the stems
or leaves were found.
Longleaf pondweed plant parts, found
in 1,274 gizzards, amounted to 1.70 per
cent of the total organic contents of all
gizzards examined, table 38. It ranked
sixth in the occurrence-percentage index,
table 37. Apparently, use of this plant
varied from one period to another, but at
no time did it constitute more than a sup-
plemental food.
Red-Rooted Nut-Grass
Cyperus erythrorhizos
Red-rooted nut-grass, a moist-soil plant
that grows on mud flats and mud banks
of both the Illinois and Mississippi river
valleys, ranked sixth among food plants
in percentage of total organic contents of
gizzards examined, table 38, and seventh
in the occurrence-percentage index, table
37. Because growing conditions were
I~Linois NaturAL History Survey BULLETIN
Vol. 27, Art. 4
much better for plants of this type in 1939
and 1940 than in 1938 (Bellrose 1941:
252-3), the volume of seed and its acces-
sibility to ducks was greater. This nut-
grass was found in significant amounts in
the gizzards of several of the important
duck species; it made up the largest per-
centages of organic material in gizzards of
the blue-winged teal, green-winged teal,
and shoveler. In most cases, the entire
seed head had been clipped off; in other
cases, individual seeds had been strained
from the bottom ooze or from the water
surface. Some pintail gizzards contained
amounts estimated at 25,000 seeds each.
This plant was represented in 617 giz-
zards, table 38, and constituted 3.71 per
cent of the plant contents or 3.51 per cent
of the total organic contents of all duck
gizzards examined. There appeared to be
little change in the rate of its utilization
as the fall months advanced. This nut-
grass appeared to be an excellent all-season
duck food.
Water-Hemp
Acnida altissima
Water-hemp, or pigweed, fig. 11, an
important moist-soil plant that occurs on
Fig. 10.—Longleaf pondweed (Potamogeton nodosus), known also as deer’s tongue. Ducks
feed on the seeds of this plant.
,
Fig. 11—Water-hemp or pigweed (Acnida
altissima). This plant grows well on mud
flats.
mud flats, ditchbanks, and similar areas,
is a good source of duck food in seasons
favorable to its growth. It ranked eighth
in the occurrence-percentage index, table
37. This plant is subject to poor seed
yields when growing conditions are un-
favorable, such as occurred in 1938 and
1939. In those years, it was represented
in only about 1 per cent of the total or-
ganic contents of the duck gizzards exam-
ined, but in 1940, a year in which beds
were abundant and luxuriant, its volume
increased to 8.18 per cent. The puddle
ducks, especially the mallard, pintail, and
both teals, used this plant. It was not un-
common to find 40,000 seeds in a mallard
gizzard, or 25,000 to 30,000 in a pintail
or teal gizzard. Only the seeds and seed
heads of this plant were used.
Water-hemp seeds or seed heads, found
in 695 gizzards, table 38, made up 2.52
per cent of the total organic contents of all
gizzards included in this study. Appar-
ANDERSON: Foop Hasits or Micratory Ducks 333
ently, the usage of this food plant through-
out the fall changed little as long as the
seeds were accessible. An early freeze
would probably have lessened its use, but
the 1938-1940 study did not indicate any
decrease in percentage of use as the season
progressed. Water-hemp can be consid-
ered a good all-fall food for most species
of dabbling ducks.
Nodding Smartweed
Polygonum lapathifolium
Nodding smartweed, fig. 12, grew abun-
dantly along the margins of most Illinois
rivers and bottomland lakes in 1938-
1940. Gizzard analyses showed that most
of the important species of waterfowl fed
on the seeds in significant amounts. Seed,
produced in abundance, seemed to serve
principally as a supplemental food, as it
never constituted a complete feeding.
Seeds of nodding smartweed, present in
1,145 gizzards, table 38, constituted 0.92
per cent of the total organic contents of
all gizzards examined. The period of
1
Fig. 12.— Nodding smartweed (Polygonum
lapathifolium). The long, drooping, densely
flowered spikes distinguish this plant from
other smartweeds.
334 ILLINoIs NATURAL History SuRVEY BULLETIN
greatest consumption occurred the latter
half of October; during the fall the pro-
portion of these seeds in the gizzards
dropped from 1.62 per cent to 0.56 per
cent of the plant foods.
This smartweed can be considered only
a fair source of all-fall food, except lo-
Lees ae 7
a cS Ue
|
Fig. 13.—Large-seeded smartweed (Polyg-
onum pensylvanicum), known also as Penn-
sylvania smartweed. A moist-soil plant, this
smartweed ranked below marsh smartweed
and nodding smartweed as an Illinois duck
food in the years of this study.
cally where the plant is easily accessible.
It ranked ninth in the occurrence-percent-
age index, table 37.
Buttonbush
Cephalanthus occidentalis
This shrub is very abundant in the val-
leys of both the Illinois and the Mississippi
rivers. Even though its seeds are a fair
duck food, the buttonbush is not a desira-
ble plant to have in a waterfowl] habitat,
Vol. 27, Art. 4
as it tends to crowd out more favorable
duck food plants. However, this shrub is
less undesirable in a waterfowl habitat
than lotus or river bulrush, which have lit-
tle value as duck food plants. Seeds of the
buttonbush were found in small quanti-
ties in the gizzards of all important spe-
cies of dabbling ducks.
Present in 690 gizzards, the seeds of the
buttonbush represented 1.31 per cent of
the total organic contents of all gizzards,
table 38. Throughout the fall season, the
percentage of seeds consumed varied very
little from week to week. Buttonbush may
be considered as a fair supplemental duck
food plant, table 37.
Large-Seeded Smartweed
Polygonum pensylvanicum
The large-seeded smartweed, fig. 13,
ranked eleventh in the occurrence-percent-
age index, table 37. Utilization of this
plant by ducks in II]linois was subject to
change from year to year and place to
place and was dependent principally on ac-
cessibility. For instance, along the Mis-
sissipp1 River, where this smartweed ap-
peared to be easily accessible during the
years of this study, it ranked first among
native foods, table 38. The seed was the
only part of this plant found in the duck
gizzards examined.
Seeds of this smartweed, in 599 giz-
zards, table 38, made up 1.01 per cent of
the entire organic contents of all gizzards.
Apparently the seeds were eaten through-
out the fall, but were more important in
the diet during the latter part of Novem-
ber and December than at other times.
Nut-Grass
Cyperus strigosus
Like the red-rooted nut-grass, this spe-
cies grows on certain mud flats and other
moist areas. It ranked high among the im-
portant foods preferred by the pintail,
blue-winged teal, and green-winged teal
in the years of this study. Apparently both
seeds and seed heads were avidly con-
sumed. Some pintail and teal gizzards
contained as many as 10,000 seeds each.
Structures of this plant, found in 384
gizzards, constituted 1.58 per cent of the
total plant contents and 1.49 per cent of
the total organic contents of the gizzards
examined, table 38. Apparently heaviest
rt ens
ON ee he ee ee eee
ir
August, 1959
Fig. 14.—Chufa
of several nut-grasses that grow on moist soil]
(Cyperus esculentus), one
in Illinois. Ducks feed
tuhers.
upon the seeds and
use of this plant occurred during Novem-
ber, when its principal consumers were
most abundant.
As with most moist-soil plants, in years
and in places in which the seed was pres-
ent and accessible, this nut-grass was a
good source of waterfcwl food during the
fall months. It ranked twelfth in the cc-
currence-percentage index, table 37.
Chuta
Cyperus esculentus
Chufa, fig. 14, occurred rather sporad-
ically on mud flats, ditchbanks, and other
moist ground in the areas from which giz-
zards were collected. It was a preferred
food of the blue-winged teal, green-winged
teal, and pintail, which consumed seeds,
seed heads, and tubers. Several hundred
seeds were taken from a few of the teal
gizzards.
Structures of this plant were found in
385 gizzards and constituted 1.36 per cent
of the total organic contents of the giz-
_zards examined, table’ 38. As with the
other moist-soil plants, chufa received the
heaviest use during November. This nut-
grass furnished good waterfowl food dur-
ing the fall months when water conditions
made the plants accessible. It ranked third
ANDERSON: Foop Hasits or Micratory Ducks 335
among nut-grasses in the occurrence-per-
centage index, table 37.
Walter’s Millet
Echinochloa walteri
Although the seeds of Walter’s millet,
fig. 15, are much smaller than those of the
wild millet, they were eagerly consumed
by the ducks represented in this study.
Walter’s millet often volunteers in muck
areas generally wetter than those contain-
ing wild millet. Seeds of Walter’s millet
were found in the gizzards of most puddle
ducks—in relatively largest amounts in
gizzards of the pintail, green-winzed teal,
and blue-winged teal. The fruit is more
y 4
Fig. 15—Walter’s millet (Echinochloa wal-
teri), sometimes called corn grass. Its small
seeds are consumed in considerable numbers
by mallards, pintails, and teals.
336
persistent than that of the wild millet and
is therefore available for waterfow] later
in the season.
Walter’s millet was represented in 243
stomachs, table 38, and constituted 2.09
per cent of the total organic contents of
all gizzards. It is a good source of late-
fall waterfowl food. It ranked fourteenth
in the occurrence-percentage index, table
Eve
Sago Pondweed
Potamogeton pectinatus
Sago pondweed, fig. 16, according to
Martin & Uhler (1939) is one of the
most important duck food plants in the
United States. In 1938-1940, this plant
appeared to be relatively unimportant in
Illinois; here the plant was spotty in dis-
tribution and it produced very little seed
(Bellrose 1941:266). Although sago
ranked low among the important plants in
the present study, table 37, most species of
ducks, especially the divers, fed on the
limited seed supply, tubers, and leaf struc-
tures.
Portions of the plant, found in 630 giz-
zards, represented only 0.64 per cent of
CRS SSS
SS }
n \ as A
%
“ — SS
~<
Intinois NaturRAL History Survey BULLETIN
Vol. 27, Art. 4
the total organic contents of all gizzards
examined, table 38. In no half-month pe-
riod did it vary considerably in volume or
number of occurrences from the average.
If this plant had been more abundant
and if it had produced more seed, it un-
doubtedly would have ranked much higher
in the food preference list.
Duck-Potato
Sagittaria latifolia
The duck-potato, fig. 17, was shown by
this study to rank low among the import-
ant duck food plants in Illinois, table 37.
Although it occurred sparingly in the areas
from which gizzards were collected in
1938-1940, it produced a moderate
amount of seed (Low & Bellrose 1944:
13). Analyses of gizzard contents showed
that most species of waterfowl fed on the
seeds and tender roots; however, only the
large ducks were able to use the tubers.
The usefulness of this plant seemed to be
partly dependent upon accessibility—on
water levels sufficiently high to allow the
ducks to feed in the duck-potato beds.
Structures of this plant, found in 167
gizzards, comprised 1.31 per cent of the
a ”
Nick
Saige
Ss SS
ON
‘
7 SSTRARS
Sey
\
Fig. 16.—Sago pondweed (Potamogeton pectinatus), known also as teal grass and eel grass.
Ducks feed upon its seed, foliage, and tubers.
August, 1959
Fig. 17.—Duck-potato (Sagittaria latifolia),
known also as arrowhead, wapato, or boot-
jack. Ducks value it more for its seed than for
its tubers.
total organic contents of the gizzards col-
lected for examination, table 38. The
plant apparently increased in duck food
value as the fall season waned. In Octo-
ber, it represented less than 1 per cent of
the plant contents of gizzards, but 3 per
cent by December. This plant may be
considered a fair duck food throughout
the fall, increasing in importance as the
season advances.
River-Bulrush
Scirpus fluviatilis
River-bulrush seeds occurred in about
one-tenth of the duck gizzards collected
in 1938-1940 from areas along the IIli-
nois and Mississippi rivers, table 38. “The
total quantity of river-bulrush seeds was
only 0.29 per cent of all the organic food.
The number of gizzards in which river-
bulrush seeds were found (510) is con-
sidered large in view of the fact that seed
production of this plant is poor in IIlinois
(Bellrose & Anderson 1943:430). Evi-
dently the seeds are very palatable.
Teal Grass
Eragrostis hypnoides
Teal grass was found to be another
moist-soil plant that ranked among the
ANDERSON: Foop Hasits or Micratrory Ducks
BLY
important sources of duck food in the pe-
riod of this study, table 37. Under cer-
tain conditions, when water levels were
sufficiently high to flood the plants grow-
ing along ditchbanks and mud flats, it
ranked much higher than when conditions
were less favorable. It appeared among
the important native foods because of large
numbers of seeds consumed by a relatively
small number of ducks. The green-winged
teal, blue-winged teal, and pintail fed
more upon this plant than did other spe-
cies of ducks.
Seeds of teal grass, found in 114 giz-
zards, constituted 0.96 per cent of the total
organic contents, table 38. After Novem-
ber 15, utilization of this plant rapidly de-
creased. The drop was due partly to ice
fringes that prevented ducks from having
access to the seeds and partly to a decrease
in numbers of the ducks that were the
principal consumers of these seeds. Teal
grass may be considered a fair source of
early-fall food but a poor source of late-
fall food.
Giant Bur-Reed
Sparganium eurycarpum
Giant bur-reed occurred in small beds
scattered among the bottomland lakes of
the Illinois River valley in the years giz-
zards were collected for this study. De-
spite the very limited occurrence of giant
bur-reed, a comparatively large number of
gizzards, 286 from the Illinois River val-
ley and 24 from the Mississippi River val-
ley, contained seeds of this plant, table 35.
The high rate of utilization indicates that
ducks found the nutlike seeds of the giant
bur-reed very palatable, but that the small
quantity available limited the importance
of giant bur-reed, which ranked last
among the 19 most important plants, table
ad.
ANIMAL FOODS
This study indicated that animal foods
were not important in the diet of most
species of waterfowl migrating through
Illinois in the autumns of 1938, 1939, and
1940, although impressive numbers of ani-
mal groups were found in the gizzards
collected. The lesser scaup duck, ring-
necked duck, shoveler, blue-winged teal,
and green-winged teal were among the
338 Ittinors NarurAL History Survey BULLETIN Vol. 27, Art. 4
Table 39.—The most important animal foods of ducks taken along the Illinois River,
Ottawa to Florence (4,505 gizzards), and along the Mississippi River, Rock Island to Quincy
(472 gizzards), 1938-1940.
Ittrnots River Mississipp1 River
Occur- Volume | Per Cent Occur- Volume | Per Cent
ANIMAL rence (eae ; rence Cubi f
(Number eto oO. | (Number (Cubic e
of Giz. Centi- | Organic SCE. Centi- | Organic
shal meters) | Contents mas dic) meters) | Contents
TOTAL ANTAL 550. sh eases PE ee ae SAG We i ee 9.64
BRYOZOA, moss animals.......... 136 9.97 0.05
MOLLUSCA
GASTROPODA, snails
Stagnicola....... a ava snes Sem Cie 3 5.70 0.03 |. 02... 4.3).
PIGHOPDIS aia i ink Ole constens erate 2 1.50 0.01 2 t Bia
PV CTES DING ste Paso ia thse a) Se 3 1.17 OLOL A. ke See : Oa
GYFAUIU Seon s,s niin hoe ere i, 0.58 t pir: 5M 22
COPENIER nd sane nee eee 1 0.40 t eat a8 me
PRS re ok cies esd weiss Perea a 7 3.40 0.02 1 t Pe)
PADD S aie gro Be tee ss 2 4.90 0.03 1 0.20 0.01
CMIEDEIOM Ee 5 ode Px GO 26 34.20 0.19 9 11.80 0.79
MAORTA oe eet tere eee 8 3,25 0.02 2 1.80 0.12
PAVIA COND: (dato RO an 45 43.15 0.24 10 13.80 0.93
Elampnicola ta hea tek 4 5.50 0.03 3 3.10 0.21
yes le a Sr An pee AS 3 0.90 t 1 0.80 0.05
Pleurocera.. 16 5.50 0.03 j2 0.30 0.02
Neritina.. inka 2 2.50 OVO |i: eee |e A Pe
Unidentified Gastropoda... erat: 167 | 143.49 0.79 12 10.78 0.72
PELEcYPODA, mussels
Sphaeriidae
PESSQIUIE UREN Roe eR ae 15 17.70 0.10 4 5.90 0.40
IMIBSCUI MIT aa ee 20 27.50 0.15 1 2.70 0.18
Sphacrium.... rae 45 94.50 0.52 11 16.20 1.09
Unidentified Sphaeriidae. . ay 6 23.30 0.13 + 13.70 0.92
Unionidae, fresh-water clams. . 9 10.80 0.06 9 4.89 0.33
Unidentified Pelecypoda........ 28 17.64 0.10 2 2.80 0.19
UnipenTiFIeED MoLuusca......... 81 48.94 0.27 13 18.50 1.24
ARTHROPODA
CRUSTACEA
Brameinonodas 80 vk oe es 3 1.40 0.01 San
COREpOEA ek Sor 3a ee eee 9 4.30 0.02 ae
Ostracadacc sons con Sop 105 4.20 0.02 |. Bhat
Mialaeost rate kc cuentas 27 18.91 0.10 2 2.50 0.17
INSECTA
Orthoptera.. : ori 3 0.52 t 1 t{) ea
Neuroptera, hellgrammites. . See 1 0.50 t As
Bekemeconies, mayne:
7 Sas Sea nace aie 80 31-25 er 29 13.68 0.92
CACHIS TFS Nate Bits eee oe 2, 0.10 t Gone
Odonata
Anisoptera, pace eal Bae 9 2.80 0.02 4 2.10 0.14
Zygoptera, damselflies........ 17 14.00 0.08 1 t ..|: ce
Unidentified Odonata........ 6 3.60 0.02) )..0 5.08 oe aah er
Homoptera
Cicadellidae, leafhoppers... . . 3 0.20 t 1 t Le ;
Hemiptera
Corixidae, water boatmen.. 329 | 128.52 0.71 37 4.33 0.29
Notonectidae, backswimmers.. 2 oy yen le Wee er
Nepidae, waterscorpions. . 2 uw wvlry whales ceva |
Belastomatidae, water bugs. 22 T7735 0.10 1 0.12 0.01
Gerridae, water striders. . 2 . Bu. mel Bee». See er
Miridae, Lygus, plant bugs. . 1
Lygaeidae, chaiteh begsse os vee 1
August, 1959 ANDERSON: Foop Hapits oF Micrarory Ducks 339
Table 39.—Continued.
Ittinots River Misstssippt River
A Occur- Volume | Per Cent Oceur- Volume | Per Cent
eee Ree oll «(Cubic of For (Cubie of
(Number Cand O - | (Number eae O :
PGi enti- rganic | * 5 Gi ‘enti- rganic
SS meters) | Contents zards) | meters! Contents
oreidae, squash bugs........).020.... Bee 1 0:12 0.01
Pentatomidae, stink bugs... . . 3 0.40 t £3 See eee ee eras
Unidentified Hemiptera....... 5 0.57 t
Coleoptera
Carabidae, ground beetles..... 46 Sp. 0.01 8 One 0.01
QUO BIGOT Er sates tas Od a aS aa Se ae 1 0 20 0.01
Haliplidae. . e 3 0.17 € ae et aes
Dytiscidae, diving beetles. . D277, 23297) 0.13 8 0.35 0.02
Gyrinidae, whirligig beetles. . . 8 0.37 t 1 0.10 0.01
Hydrophilidae, water scaven-
ger beetles. . is = 6 0.90 t 4 6.00 0 40
Staphylinidae, r rove beetles. ... 6 0.29 t are eee
Puprestidae, fatheaded wood
orerss 4-4-5 J t
Drvopidae... 2.20.00... 1 t
Elmidae ; 2 t 5 the intel
Scarabaeidae, scarab beetles. . 6 0.86 t 3 0.27 0.02
Chry somelidae, leaf beetles... 12 0.50 ey Bec
Curculionidae, snout beetles . 17 2.90 0.02 3 0.20 0.01
Unidentified Coleoptera. .... 6 0.55 t cA ee
Trichoptera, caddisfies
Hydroptilidae. . 132 Se, 0.03 | t
Hydropsychidae. 5 ee tae oe 13 11.66 0.06
Unidentified Trichoptera sco 19 PAIL 0.01 cae ee
Lepidoptera.. ee 4 0.39 t 1 0.09 0.01
Diptera, flies
Chironomidae, midges........ 238 127.61 0.70 10 4.70 0.32
TVabanidae, horse fiies.......- 2 0.50 t Hens ene
Anthomyiidae. . Ronit te 1 0.09 t 1 0.20 0.01
Unidentified Diptera. . 14 5.63 0.03 0.10 0.01
Hymenoptera
Ichneumonidae, ichneumons. . 3 0.05 t tA:
Tiphiidae, Tiphia, tiphiid wasps 22 0.10 t ne a
Formicidae, ants. 6 0.10 t 2! 0.08 t
Unidentified Hymenoptera. 1 0.96 t oid at ee
Unidentified Insecta. . et 15 5.09 0.03 Pee Sie:
ARACHNIDA....... ne Srat nee” 21 0.72 t 7 0.14 0.01
ACARINA, water mites. 75 0.37 t Abe ae
CHORDATA
Pisces, fish. eer 18 0.72 t 1 t
AMPHIBIA, frogs... me 1 1.00 te [ae ee eset cy llb eons aon
UNIDENTIFIED ANIMAL. .... 4 0.80 t 2 t
NONFOOD
PARASITIC WORMS oc. 32.5 002% 00: 1 0.20 t Ste eater
ER RATENBIS Se iets aio ninie = va & 83 8.72 0.05 8 0.52 0.03
species that were the principal consumers
of animal foods.
Animal parts constituted 5.52 per cent
of the organic contents of all waterfowl
- gizzards collected in the years of the study.
The two outstanding animal groups were
mollusks and insects, table 39. The for-
mer comprised 55.66 per cent of the total
animal foods and the latter 39.32 per cent.
Crustaceans comprised 2.89 per cent of
the animal foods.
Mollusca
Snails comprised 49.47 per cent of the
Mollusca and 27.54 per cent of the ani-
mal foods, while mussels constituted 39.36
340 Intrnois NatrurAL History Survey BULLETIN
per cent of the Mollusca and 21.90 per
cent of the animal foods, table 39.
Fresh-water snails found in the largest
numbers of duck gizzards were 4 mnicola,
Campeloma, and Pleurocera. Fragments
of a brackish water snail, Neritina, were
found in two gizzards. ‘he mussels iden-
tified were of no commercial use; most of
them were small and thin shelled. Genera
represented included Sphaerium, Pisidium,
and Musculium.
Insecta
The insects represented 2.17 per cent of
the total organic foods and 39.32 per cent
of the total animal foods in the gizzards
examined, table 39. Many species of in-
sects were represented in gizzards collected
prior to November 15, but after this date
the volume and the number of species of
insects decreased. This decrease was due
in part to a decline in the populations of
ducks that feed upon insects and in part to
a decline in the number of insects avail-
able.
Among the insect material found in
greatest volume in the duck gizzards were
Odonata nymphs, midge larvae, mayfly
nymphs, fig. 18, caddisfly larvae, and
water boatmen.
Crustacea
In the duck gizzards collected, Crus-
tacea constituted only a small portion of
the animal foods, table 39; in greatest
volume were the crayfish (Malacostraca).
The minute forms appeared in many giz-
zards but in negligible volumes; among
them were water fleas (Branchiopoda),
amphipods and pillbugs (Malacostraca),
and ostracods.
Bryozoa
These small animal forms appeared
most often as traces in the duck gizzards
collected. “The winter buds or statoblasts
of Pectinatella and Plumatella probably
had been eaten along with other foods.
Amphibia
Frog bones appeared in only one giz-
zard.
Arachnida
A few spiders and water mites were
found in the contents of the gizzards col-
Vol. 27, Art. 4
Fig. 18.—Mayfly nymph of the genus Hexa-
genia. This is one of the animal foods con-
sumed by ducks that migrate through Illinois
in autumn,
lected ; they were not considered important
waterfowl foods.
Pisces
Fish vertebrae and scales were occasion-
ally found in the duck gizzards collected.
Mallards and black ducks have been
known to feed extensively on gizzard
shad, Dorosoma cepedianum.
GRIT
Generally grit is considered to have two
functions in avian nutrition: (1) assisting
the gizzard in the grinding of food and
(2) furnishing necessary minerals for me-
tabolism and reproduction (Nestler 1946:
137). Because grit invariably appeared in
the gizzards examined in the present study,
it seems reasonable to conclude that ade-
quate supplies of hard, nonfriable particles
were available to waterfowl in the Missis-
sippi Flyway. Experiments with captive
wild mallards have shown, moreover, that
the grit demands of waterfowl may be low
even in areas of grit abundance. When
supplied with granite grit, each of 30 mal-
lards under observation at the Havana lab-
oratory of the Illinois Natural History
Survey took an average of slightly less
than one piece per day for a period of 1414
August, 1959
ANDERSON: Foop Hasits of Micratory Ducks
341
Table 40.—Grit contents of duck gizzards collected in Illinois, 1938-1940.
AVERAGE AVERAGE
AVERAGE
SPECIES GizzarD CAPACITY cr as G PER CENT OF
(Ciara (Caan ee ER GIZZARD IZZARD CAPACITY
(Cusic CENTIMETERS)| OccuplieD By Grit
lal levrd lc Sie a 16.0 2.95 18.44
FLAG. 9 14.0 Dei 16.50
6 2k OIE, ta ce ean a 13.0 2.87 22.08
(Cavalyailll © 60 ei pee ae 14.0 3.85 27.50
\ vera la bre) aa 9.0 1.91 DA 92)
Green-winged teal............. 325 0.83 Deere T/il
Pane-winged teal.............. S7/ 0.40 10.81
Snowe AS ee 6.0 Le vAl 28.50
Wanvasbacks os... as hens 14.5 3.01 20.76
fuel eave). <0 oe tee 14.0 2.78 19.86
| SS2 EG 0k Oe Sad 1.00 11.76
Ring-necked duck... 8.5 153 18.00
months. Though additional grit was eas-
ily available, some mallards retained the
same particles for as long as 714 months.
Evidence of the ability of ring-necked
pheasants and bobwhites to retain grit in
their gizzards for 6 weeks or more has
been presented by Gerstell (1942:72-9)
and Nestler (1946:141). Grit as a grind-
ing agent in the gizzards of the bobwhite
quail, Colinus virginianus, was not essen-
tial for growth, health, or reproduction,
Nestler found.
In gizzards collected for the present
study, grit occupied an average of 10.81
to 28.50 per cent of the gizzard capacity
in the various species of ducks, table 40.
‘The data indicate no correlation between
amount of grit and size of duck, type of
food (plant or animal), type of feeder
(puddler or diver), or feeding habitat.
Grit in the gizzards collected for the
present study was composed principally of
rough, angular particles of quartz and
chert and some limestone. Particles were
Table 41—The number of ducks of various species represented by gizzards collected in
Illinois in 1938-1940 and the number of these gizzards that contained lead shot pellets, some
worn (ingested) and some unworn (embedded).
NumBer or | NuMBER OF Number oF Petters
SPECIES GIzzARDSs GizzaRDs
EXAMINED Wir Sxot Worn | Unworn | Total
Mla era la stench in Ge ea eee 2,825 250 404 140 544
MME OBR on 5g Ga) mtosedi 4 i ged aa 881 71 104 42 146
Bena RR Ane Sohne ware 3 160 4 3 3 6
(Cavallo epee tas as OAS ene meee tae 98 2 nets 2 2
DESL GiGi Ae gee eee ee 26 At hits Sap og -
arecn-winged teal... :......3..5.-.5: 393 5 66 4 70
Pame-wineed teal: oi.) css y cakes ta ce 129 3 1 2 3
SOW Clete tT Toar paste. cst oe athens, teks 62 SAS es Re ea ee
PARC ey nee sh ss sees 28 4 9 atts 9
DDE EN RSet ee eee ee ae 14 2 5 1 6
LIVERS) Cn Aa eae ae en ee 220 43 450 19 469
Memenecked ducks... soi, -.0nh+ ek 120 22 129 ii 148
DMEM Ketek es hh cap nieve u's 208s 11 3 6 6
SSE LOSG NT a ee ei 5 yeh ae
ommon goldeneye..:...21.........- 3
PCC RSIVSCHUIN os gout, sled aire Pha vee 1
MN eee, es 1 Serie ET a3 See at” Ree Ma
INGLIS i AOS, coh Rady MAO on a pe ae 4,977 409* ILIA 232 1,409
*Of these gizzards, 190 represented ducks in which shot had entered the gizzards at the time the birds were killed.
The other 219 represented ducks that had ingested shot.
342 Iuntrnoris Natrurat History Survey BULLETIN
measured in millimeters across the widest
dimension regardless of tlie shape. ‘1 hese
varied from minute to 19 mm. in size;
most of them were under 2 mm. Grit in
mallard, pintail, ring-necked duck, and
lesser scaup gizzards consisted mostly of
stones over 9 mm. in size. Baldpate and
gadwall gizzards seluom contained gritty
material larger than sand particles. Teal
and shoveler gizzards seldom contained
stones over 2 mm.
The frequency with which sand _ oc-
curred to the exclusion of stones in the
baldpate and gadwall gizzards suggests a
relationship between the food habits and
physical composition of the grit ingested
by these species. Baldpates and gadwalls
generally feed on soft, leafy aquatic plants,
which are likely to require little or no
grinding during the digestive processes,
and the sand recovered from the gizzards
Vol. 27, Art. 4
of these ducks may have been taken only
because it adhered to the food; or it may
have been unintentionally taken during
normal feeding activity.
Shell fragments, rather than stones,
were found in the gizzards of many lesser
scaups, ring-necked ducks, redheads, gold-
eneyes, and shovelers. Many other par-
ticles classified as inorganic material were
found in the gizzards examined. Fossil
fragments of crinoid stems, wood, coral,
‘and brachiopod shells were not uncommon.
Muskrat and fish teeth were numerous.
Most of these items were rough and angu-
lar, serving as excellent grinding agents.
LEAD SHOT
Lead shot pellets were found in the giz-
zards of most of the species of ducks in-
cluded in this study, table 41. Some of
Table 42.—The number of duck gizzards collected in Illinois in each of 3 years, the num-
ber and percentage of these that contained lead shot pellets, and the number of pellets per giz-
zard among the gizzards that contained lead.
NuMBER NuMBER Per Cent Tora NuMBER OF
Ges OF OF OF NuMBER PELLETS PER
5 GizzARDS G1zzARDS GizzARDS OF G1zzarD
EXAMINED Wir SxHor Wir SHor PELLETS Wirn SHor
1938. 1,814 159 8 8 998 6.3
1939. 2,291 191 8.3 332 ie?
1940 872 59 6.8 79 1.3
OLB ee 4,977 409* 1,409
*Of these gizzards, 190 represented ducks in which shot had entered the gizzards at the time the birds were killed.
The other 219 represented ducks that had ingested shot.
Table 43.—The number of duck gizzards collected in Illinois by Dameek periods, 1938-1940, —
the number and percentage of these that contained lead shot, and the number of worn (in-
gested) pellets per gizzard among the gizzards that contained lead.
NuMBER OF
NuMBER OF NuMBER OF Per CENT OF NuMBER Worn
PERIOD G1zzARDS G1zzARDS G1zzARDS or Worn PeLLets PER
EXAMINED Wirn SHor Wirn SHor PELLETS GizzARD
Wirtn SHor
October
15307 Fe 1,607 89 D5) 84 0 94
November
NaS ties ok oe 1,466 101 6.9 297 2.9
November
D5 —SO acs sees 1,424 185 13.0 746 4.0
December
Er tS eee ena te 480 34 7 fs | 50 1.5
Wola soo aoe 4,977 409* oe 1,177 |.
*Of these gizzards, 190 represented ducks in which shot had entered the gizzards at the time the birds were killed.
The other 219 represented ducks that had ingested shot.
August, 1959 ANDERSON :
these pellets had been ingested by ducks in
their feeding and some had become lodged
in the gizzards at the time the birds were
killed.
The lining of many gizzards containing
lead shot was dark green in color. Any
duck from which a gizzard of this color
had been taken was considered to have
been sick before it was shot.
Water levels and firmness of lake or
marsh bottoms are among the factors that
determine the accessibility and availability
of lead shot to waterfowl (Bellrose 1959:
249). Although the percentage of giz-
zards containing lead pellets did not vary
greatly from year to year for the 3-year
period of the study, the average number
of pellets per gizzard changed materially,
table 42.
Probably the lead shot was consumed in
the season it was deposited rather than in
a subsequent season (Bellrose 1959:266).
The gizzard contents showed an increase
in percentage of gizzards with lead shot as
well as an increase in the number of pel-
lets per gizzard as the autumn progressed,
table 43.
SUMMARY
1. In the autumns of 1938, 1939, and
1940, duck gizzards totaling 4,977 were
collected from hunting clubs and _ indi-
vidual hunters at 21 sites along the IIli-
nois River between Ottawa and Florence
and 11 sites along the Mississippi River
between Rock Island and Quincy. The
following 17 duck species were repre-
sented: mallard, pintail, green-winged
teal, blue-winged teal, baldpate, gadwall,
shoveler, black duck, wood duck, lesser
scaup, ring-necked duck, redhead, canvas-
back, ruddy duck, greater scaup, common
goldeneye, and oldsquaw.
2. Analyses of the gizzard contents
were made in accordance with the proce-
dure instituted and followed by the U. S.
Fish and Wildlife Service, Department of
the Interior.
Foop Hapsirs or Micratory Ducks
343
3. ‘The analyses indicated that, during
the fall, most species of ducks in [Illinois
are predominantly vegetarians, that most
of them feed principally on native wild
plants, and that the lesser scaup is the only
species with a diet predominantly animal.
4. Corn made up nearly half of the or-
ganic contents of mallard gizzards. Na-
tive wild foods were present in relatively
greater quantities in gizzards of the wood
duck, pintail, redhead, baldpate, green-
winged teal, and ring-necked duck, all of
which included corn in their diets.
5. Of the 95 wild plants and 4 cul-
tivated plants found in the gizzards and
identified to species, the following 19 were
most important: corn, rice cutgrass, marsh
smartweed, coontail, wild millet, longleaf
pondweed, red-rooted nut-grass, water-
hemp, nodding smartweed, buttonbush,
large-seeded smartweed, nut-grass, chufa,
Walter’s millet, sago pondweed, duck-
potato, river-bulrush, teal grass, and giant
bur-reed.
6. The relative positions of the impor-
tant food plants changed from year to year
as accessibility and availability varied.
7. The importance of a plant species
to a species of duck depended on the size
of the duck and the type of feeding habitat
frequented by the duck.
8. The dabbling ducks fed primarily on
emergent and moist-soil plants and the div-
ing ducks more frequently on submergent
plants. Animal foods were more important
to diving ducks than to dabbling ducks.
9. Snails and mussels provided the
largest animal food volume and occurred
in the largest number of gizzards. Insects
were second in volume and occurrence.
10. Grit constituted about 11 to 28 per
cent of the gross contents of the gizzards
of various duck species. Most of the stones
were less than 2 mm. in size; the sizes
ranged from minute to 19 mm. in size
(largest dimension).
11. More than 200 of the gizzards ex-
amined contained lead shot pellets that
had been ingested.
LITERATURE CITED
Bellrose, Frank C.
1938. Abundance and food habits of the waterfowl in the Illinois River valley. Bachelor’s
thesis, University of Illinois, Urbana. 33 pp.
1941. Duck food plants of the Illinois River valley. Ill. Nat. Hist. Surv. Bul. 21(8) :237-80.
1959. Lead poisoning as a mortality factor in waterfowl populations. Ill. Nat. Hist. Surv
Bul. 27(3) :235-88.
Bellrose, Frank C., and Harry G. Anderson
1940. Preliminary report on availability and use of waterfowl food plants in the Illinois
River valley. Ill. Nat. Hist. Surv. Biol. Notes 15. 14 pp. Mimeo.
1943. Preferential rating of duck food plants. Ill, Nat. Hist. Surv. Bul. 22(5) :417-33.
Cottam, Clarence
1936. Economic ornithology and the correlation of laboratory and field methods. U. S&S,
Biol. Surv. Wildlife Leaflet BS-30. 13 pp. Mimeo.
Gerstell, Richard
1942. The place of winter feeding in practical wildlife management. Pa. Game Comn. Res.
Bili73: cL pp:
Fernald, Merritt Lyndon
1950. Gray’s manual of botany. Ed. 8. American Book Company, New York. 1,632 pp.
Hawkins, Arthur S., and Frank C. Bellrose :
1939. The duck flight and kill along the Illinois River during the fall of 1938. Am. Wild=
life 28(4) :178-86.
Hawkins, Arthur S., Frank C. Bellrose, Jr.. and Harry G. Anderson ;
1939. The waterfowl research program in Illinois. Ill. Nat. Hist. Surv. Biol. Notes 12.
16 pp. Mimeo. 4
Low, Jessop B., and Frank C. Bellrose, Jr.
1944. The seed and vegetative yield of waterfowl food plants in the Illinois River valley
Jour. Wildlife Mgt. 8(1) : 7-22.
Martin, A. C., and F. M. Uhler
1939. Food of game ducks in the United States and Canada. U. S. Dept. Ag. Tech. Bu
634. 156 pp.
Nestler, Ralph B.
1946. Mechanical value of grit for bobwhite quail. Jour. Wildlife Mgt. 10(2) :137-42.
Wetmore, Alexander
1919. Lead poisoning in waterfowl. U. S. Dept. Ag. Bul. 793. 12 pp.
L 344 ]
Some Publications of the TLttNois NaTuRAL History SURVEY cM ie
BULLETIN
Volume 26, Article 3.—Natural Availability
of Oak Wilt Inocula. By E. A. Curl. June,
1955. 48 pp., frontis., 22 figs., bibliog.
Volume 26, Article 4.—Efficiency and Selec-
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on the Mississippi River. By William C.
Starrett and Paul G. Barnickol. July,
1955. 42 pp., frontis., 17 figs., bibliog.
Volume 26, Article 5.—Hill Prairies of Illi-
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80 pp., frontis., 28 figs., bibliog.
Volume 26, Article 6—Fusarium Disease of
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22 figs., bibliog.
Volume 27, Article 1.—Ecological Life History
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August, 1957. 84 pp., color frontis., 27 figs.,
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Research. By Harlow B. Mills, George C.
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S. Ayars, Ruth R. Warrick, and Bessie B.
East. December, 1958. 150 pp., 2 frontis.,
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By Frank C. Bellrose. May, 1959. 54 pp.,
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July, 1958. (Fifth printing, with revisions.)
32 pp., frontis., 8 figs.
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By Ralph E. Yeatter. December, 1948. 64
pp., frontis., 40 figs.
45.—Housing for Wood Ducks. By Frank C.
Bellrose. February, 1955. (Second print-
ing, with revisions.) 47 pp., illus., bibliog.
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Cedric Carter. August, 1955. 99 pp.,
frontis., 93 figs. Single copies free to IIli-
nois residents; 25 cents to others.
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Enemies. By L. L. English. May, 1958. 92
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BIOLOGICAL NOTES
29.—An Inventory of the Fishes of Jordan
Creek, Vermilion County, Illinois. By F
Weldon Larimore, Quentin H. Pickerin ig, :
and Leonard Durham. August, 1952. 26
pp., 25 figs., bibliog.
30.—Sport Fishing at Lake Chaotanaiae near
Havana, Illinois, in 1950 and 1951. By
William C. Starrett and Perl L. McNeil,
Jr. August, 1952. 31 pp., 22 figs., pert! i
31—Some Conservation Problems of —
Great Lakes. By Harlow B. Mills. Octori
ber, 1953. (Second printing.) 14 PP, its
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33.—A New Technique in Control oft the 2
House Fly. By Willis N. Bruce. D ‘4
ber, 1953. 8 pp., 5 figs.
34,—White-Tailed Deer Populations in
nois. By Lysle R. Pietsch. June, 1954,
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Thomas G. Scott. July, 1955. (Second
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36—A Spectacular Waterfowl Migratis 4
Through Central North America. By Fra
C. Bellrose. April, 1957. 24 pp. 9 f
bibliog.
37.—Continuous Mass Rearing of the Ei
pean Corn Borer in the Laboratory.
Paul Surany. May, 1957. 12 pp. 7
bibliog.
38.—Ectoparasites of the Cottontail Rabbi
Lee County, Northern Illinois. By Lewi
Stannard, Jr., and Lysle R. Pietsch. Ji
1958. 20 pp., 14 figs., bibliog.
39—A Guide to Aging of Pheasant Embr
By Ronald F. Labisky and James F. Ops:
September, 1958. 4 pp., illus., bibliog,
40.—Night-Lighting: A Pochiaae for C
turing Birds and Mammals. By Ronald
Labisky. July, 1959. 12 pp., 8 figs., bibl
MANUAL |
3.—Fieldbook of Native Illinois Shrubs.
Leo R. Tehon. December, 1942. 307.
4 color pls., 72 figs., glossary, index. $1
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1957. 233 pp., color frontis., 119 figs., g
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ILLINOIS NATURAL HISTORY SURVEY
Bulle tin Printed by Authority of is ig Y
the State of Illinois WB:
Hook-and-Line Catch
in Fertilized and
Unfertilized Ponds
DONALD F. HANSEN
GEORGE W. BENNETT
ROBERT J. WEBB
JOHN M. LEWIS
STATE OF ILLINOIS @ Wham G. Srratron, Governor
} DEPARTMENT OF REGISTRATION AND EDUCATION @® Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION ® Harvow B. Mus, Chief
;
ILLINOIS NATURAL HISTORY SURVEY
Bulletin
Volume 27, Article 5 Saas
Printed by Authority of
August, 1960 the State of Illinois
Hook-and-Line Catch
in Fertilized and
Unfertilized Ponds
DONALD F. HANSEN
eEORGE W. BENNETT
ROBERT J. WEBB
JOHN M. LEWIS
STATE OF ILLINOIS e@ WrtiAm G. STRATTON, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION ©@® Vera M. Binks, Director
NATURAL HISTORY SURVEY DIVISION © MHartow B. Mitts, Chief
Urbana Illinois
STATE OF ILLINOIS
Wintiam G. Strarron, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
Vera M. Binks, Director
BOARD OF NATURAL RESOURCES AND CONSERVATION
Vera M. Binxs, Chairman; A. E. Emerson, Ph.D., Biology; Watter H. Newnouse, Ph.D., Geology; Rocer Apams,
Ph.D., D.Sc., Chemistry; Rornert H. Anverson, B.S.C.E., Engineering; W. L. Everitt, E.E., Ph.D., Representing the
President of the University of Illinois; Detyre W. Morris, Ph.D., President of Southern Illinois University
NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois
SCIENTIFIC AND TECHNICAL STAFF
Hartow B. Mitts, Ph.D., Chief
Bessie B. East, M.S., Assistant to the Chief
Section of Economic Entomology
Grorce C. Decker, Ph.D., Principal Scientist and Head
J. H. Biccer, M.S., Entomologist
L. L. Enouisu, Ph.D., Entomologist
W. H. Lucxmann, Ph.D., Entomologist
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Joun P. Kramer, Ph.D., Associate Entomologist
Ronatp H. Meyer, M.S., Assistant Entomologist
Ricuarp B. Dysart, B.S., Assistant Entomologist
Eucene M. Bravi, M.S., Research Assistant
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RecinaLtp Roserrs, A.B., Technical Assistant
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Fart STADELRBACHER, B.S., Technical Assistant
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sue FE. Warxins, Technical Assistant
H. B. Perry, Ph.D., Extension Specialist in Entomology*
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Entomology*
Zenas B. Noon. Ir., M. S., Research Assistant*
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Section of Faunistic Surveys and Insect Identification
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Section of Aquatic Biology—continued
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CONSULTANTS: Herrerotocy, Hosart M. Smiru, Ph.D., Professor of Zoology, University of Illinois; Parasirouocy,
Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University of Illinois ;
Wirptire Researcu, Witrarv D. Kuimsrra, Ph.D., Professor of Zoology and Director of Co-operative Wildlife
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Department of Agriculture, United States Fish and Wildlife Service, United States Public Health Service, and others.
This paper is a contribution from the Section of Aquatic Biology.
(16668—6M—5-60) aggro 2
CHOW FEIN TS
SMMBRIMERICNOWES ES OG. Safe 205 oO fine ate y ciel edna Gt at Ae ts aga biale Melee Sed Ue 345
DBERINMENTAL PONDS AND [HEIR WATERSHEDS. ...... 5... ..0.0c0c0ccceeeaecdenu 346
RUINED a ROCKIALRES.Y sais hand-nl'o.Slx 05.0 Gis''s videFir ola bin DOS cin vos Oe ree wees Pe Segoe 493
EAM PRET Ce OOS Ay, eek: co eh ATPases leds hb GaSe | a Aaa eee Se aw eae oe 353
SHED a HAE ear EMI CLS eos yc custom lacs AOR (oieie le im pees esl e wal sacks ee Gk idee Ae 354
MRE EGS SIRO TED AL Ate 40M Ae facie Obs AE ALA wee? Laklacnm apa ace omer 355
reteset OE eat Hii she OPILALIGIIS 2. & fos o: 224d ja eles nye Sos aim vide ene de eee med eee 356
OR ERELZA TION AND) PANT IOERE. 6% cola devs 2 evils ew gccte nid a vibe oes ave 4 nyalola wi aaah 356
RAMEE TMIZATION AND FISHING SUCCESS. |. 0. 2.5 < sec e006 Sie ae suclee ele eda ee nes eee 358
CT ee PE DESI S22 1 ed a a eens Cid ee age PR oe ee ES AOI ee cone ns fr 361
Amimall Blog kecin@el bitin SGiahiioe. aac nena oes ere ots 5 Gino Garo oneal ia nee 363
ea MS ee ed te eta eines Sd Sain Ae ae CS Os ea Oo eae 365
Barchelates tor, hishy What: Were: Harvested: 2.002026 wick Sos as ee es 367
Rieter Swi Ce ATRIA CALE Sie Ao ie oes « 'o Alotorerceaelshs cumin aaoetard a nae Sea Spero eS
Pisin bressureswanes Gatch ILAteS .,. osteo ni ad-aw-c. cheeisae dle weitied-o OF sie ght adhe 375
HecHiliation RALeS Ang, Catch IN AECS 3 cnc omia soso vioan dees ee eee Gases aaa 375
SPERM LIZATION AND STANDING GROPS. «s-:04 os c- b onlay oa oe ola cote oe bse ee 376
PE OROPS CAND WP ISEIING DUCCESS: 2.060 ved. be uence ree beee cease estan eeuee 380
MELERTILIZATION AND FISHING SUCCESS. 0.05525 0600 ed beac nee nent eenes ec deenc 383
MONIES OLB EO NDS ER TTOIZAMION = cuss eyo ciess ss oes siesate laos eee oenvie ean Se eisecce eke 385
Pee CAL UATIONCOR LONDS 5 o<..0+ «osc sor se cute ok oe eS elaine see acct tects Oe acts 386
ERICA UE Sve hae he eS OARS lanchtvs whic eran he ant aR eS oe 387
“react umn (CONTITSIB 2 eee 2 Se re oe ee Oe, ne a A ME Pt Oar Oa ieee Rate 389
NA. et
Pr LY, a
; Ce tee
‘ > es
ence at’
Hook-and-Line Catch
in Fertilized and
Unfertilized Ponds
XPERIMENTS carried on in the
| eae States during the past 30
years have shown that the total
weight of fish in a pond, that is, the stand-
ing crop, may be increased two to six
times through the use of fertilizers (Davis
& Wiebe 1931; Smith & Swingle 1939;
Smith & Moyle 1945; Surber 1945,
19484; Swingle 1947; Ball 1949; Ball &
Tait 1952).
These experiments have quite naturally
led to the speculation that fertilization is
a means of improving hook-and-line fish-
ing. While the practice of fertilizing
ponds has been widely recommended to
pond owners, few attempts have been
made to measure the effect of fertilization
on angling results. In published studies
of angling in ponds (King 1943; Swingle
1945; Smith 1952, 1954) results have
been inconclusive with respect to the
effect of fertilization on catch of fish per
hour.
Studies of the effects of fertilization on
aquatic plant life, on animals eaten by
fish, and on fish crops have been reviewed
by Neess (1949), Maciolek (1954), and
Mortimer & Hickling (1954).
The objective of the pond fertilization
experiment reported in this paper was to
measure the effect of certain fertilization
practices on sport fishing for largemouth
bass, Micropterus salmoides (Lacépéde),
and bluegills, Lepomis macrochirus Rafin-
esque, in small ponds located in a region
of relatively unproductive soils. From
catch records gathered over a 6-year pe-
riod, 1947-1952, from three fertilized
ponds and three unfertilized or control
ponds, we have been able to compare the
sizes of the fish caught, the annual hook-
-and-line yields, and the catch rates in
terms of fish per fisherman-hour. The
six ponds used in the experiment are lo-
*Robert J. Webb is Superintendent and John M. Lewis
is Assistant Superintendent of the University of Illinois
College of Agriculture Dixon Springs Experiment Station.
DONALD HAN SEN
GEORGE AW. BE N Nie
ROB ORT Al vO Ene
JORLN: Oc LEW ES
cated at the University of Illinois College
of Agriculture Dixon Springs Experi-
ment Station in Pope County, southern
Illinois.
The methods of stocking and fertilizing
were, in part, variations of those first pro-
posed by Swingle & Smith (1941: 224-5,
1942:12-3, 16-8). Recommendations of
Swingle & Smith for minimum fertiliza-
tion were followed closely during the last
2 years of the 6-year study.
A census of the fish population of each
of the ponds was made in the fall of 1953.
In the census operations all fish in the
ponds were killed with rotenone so that
we were able to compare standing crops
of fishes in the ponds that had been
treated with fertilizer for an extended
period (7 years) with the standing crops
in the ponds that had not been treated
with fertilizer. In addition, we were able
to compare the standing crop of fishes in
each pond with the hook-and-line fish
vields and catch rates recorded during the
last 3 years of angling.
Published data on angling success in
ponds stocked with only largemouth bass
and bluegills are scarce. The present
study demonstrates the value of this pop-
ular combination of fishes, as well as the
effect of fertilization, in southern []linois
ponds.
ACKNOWLEDGMENTS
Information on soils and soil treatments
at the Dixon Springs Experiment Station
was furnished by C. A. Van Doren of
the United States Soil Conservation Serv-
ice and by the following persons from the
University of Illinois College of Agricul-
ture: W. G. Kammlade, Leah M. Dunn,
George E. McKibben, and Leland E.
Gard. The following persons, all with
the College of Agriculture, were con-
sulted on general questions pertaining to
soils and soil fertility: A. L. Lang,
[ 345 ]
346 Ittinors NAtuRAL History SurvEY BULLETIN
Lawrence B. Miller, Roger H. Bray,
Russell T. Odell, Herman L. Wascher,
J. B. Fehrenbacher, and the late Robert
F. Fuelleman. H. W. Norton, Professor
of Agricultural Statistical Design and
Analysis, Animal Science Department, has
examined the data and has verified certain
conclusions reached in this study.
Water samples from the experimental
ponds were analyzed by T. E. Larson of
the Illinois Water Survey. Fishing boats
were provided by the Illinois Department
of Conservation through the courtesy of
Sam A. Parr, formerly Superintendent of
the Division of Fisheries, now Admin-
istrative Assistant. Help with fertilizing
the ponds or with the rotenone census was
given by R. Weldon Larimore, William
N. Nuess, Robert Crompton, and the late
Dan Avery, employed by the Illinois Nat-
ural History Survey, and by Ray Brown,
Guy Bellamy, Leonard Durham, and
Oliver Dick, employed by the Department
of Conservation.
Charles Stubbs in 1947, Maurice G.
Kellogg in 1948, 1949, and 1950, Stacy
Gebhards in 1951, and Charles R. Peters
in 1952 served as test anglers. The pho-
tograph for the frontispiece and the aerial
photographs were made by Charles Scott,
formerly employed by the Illinois Natural
History Survey and now picture editor of
the Milwaukee Journal. The other pho-
tograph was taken by George W. Ben-
nett. The manuscript was read by Wil-
liam C. Starrett and edited by James S.
Ayars and Mrs. Diana R. Braverman, all
of the Illinois Natural History Survey
staff.
EXPERIMENTAL PONDS AND
THEIR WATERSHEDS
The ponds selected for use in this ex-
periment—Lauderdale, Hooker, Phelps,
Wells, Boaz, and Elam, figs. 1-6—are
stock-watering ponds built at the Dixon
Springs Experiment Station in the period
1935-1940. All have earthen dams. All
are fenced and, during the years of the
experiment, cattle seldom had access to
them. They are all within a 2-mile radius
of the Experiment Station headquarters.
In September, 1951, at a time when
these ponds were full of water, thev
ranged in surface area from 0.92 to 1.55
Vol. 27, Art. 5
acres, and from 8.5 to 15.0 feet in maxi-
mum depth, table 1. Since the only source
of water for the ponds was surface run-
off, there was always a reduction in water
area and in depth during dry weather of
late summer. Presumably these water
level reductions varied in the six ponds in
accordance with relative size of drainage
areas, number of domestic animals using
the water, shape of the pond basins, and
rates of runoff, evaporation, and under-
ground seepage. In the fall of 1953, after
one of the driest summers on record, the
reduction in surface area of the various
ponds ranged from 13 per cent in one
pond to 49 per cent in another, table 1.
There was little difference between the
late summer levels of 1953 and those of
1952, another dry year. We have esti-
mated from general observations that late
summer water levels in 1952 and 1953
were | to 2 feet lower than those of most
other years represented in this study. Al-
though in 1953 Wells Pond showed the
greatest reduction in surface area, in most
years Phelps Pond showed the greatest
reduction.
The test anglers made weekly measure-
ments of surface water temperatures
through the summers of 1947 and 1948.
Temperatures above 90 degrees F. were
rarely encountered in the series of weekly
readings. The maximum surface tempera-
ture reading at any of the ponds was 94+
degrees, observed at Boaz Pond, first on
July 29 and again on August 5, 1947, and
at Phelps Pond on July 12, 1948.
‘Temperature measurements made at 2-
foot depth intervals on August 12, 13,
and 14, 1947, table 2, showed marked
thermal stratification in five of the six
ponds.
Chemical analyses of water from the
ponds, table 3, were made from samples
collected March 19, 1947, before the
fertilization experiment was begun. The
watersheds of all of these ponds had been
fertilized prior to the time the water an-
alyses were made, but Lauderdale Pond
was the only one that had received direct
fertilization. Before the experiment re-
ported here was planned, this pond had
been treated on two occasions in an at-
tempt to improve fishing: on August 17,
1945, with 80 pounds of ammonium sul-
fate, 32 pounds of 63 per cent superphos- —
August, 1960 HANSEN et al.: HooK-AND-LINE CaTCH 347
Fig. 1.—Aerial view of Lauderdale Pond, 0.9 acre, October, 1950. The fields on two sides
of the pond had been plowed and reseeded a few weeks before the picture was made.
Fig. 2—Aerial view of Hooker Pond, 1.33 acres, October, 1950.
348
Intrnors NaturRAL History SurveEY BULLETIN
Vol. 27, Art. 5
Table 1.—Depth and area of each of the six Dixon Springs ponds used in fertilization
study, as observed at full stage in September, 1951, and at the time of the rotenone census,
September, 1953. The levels observed in 1953 were probably as low as or lower than any levels
that occurred during the fishing period.
Lowest OBSERVED
| gEuusmor. | 'Brovowr Seige
? SEPTEMBER, 1953 REDUCTION
Ponp ane In AREA,
Depth Area Depth Area Per CENT
in Feet in Acres in Feet in Acres
FERTILIZED |
Lauderdale... =..0c0 ee 1 0.92 9.8 0.76 17
Hookeriscc 200 ees ee 14.0 1.33 10.6 1.03 23
Pee. Gir cide ete heres cee 8.5 1.04 4.5 0.70 33
UNFERTILIZED
Wellgo ice a eel 15.0 0.97 12.0 0.49 49
15 OE vt panes rah ga Oe Hl Sane 10.5 1.01 6.8 0.66 35
Elam ae 9.0 £255 6.8 135 13
phate, and 25 pounds of ground lime-
stone; and on September 8, 1945, with
80 pounds of ammonium sulfate, 100
pounds of 20 per cent superphosphate, and
25 pounds of ground limestone.
An unusual characteristic of the Dixon
Springs ponds was their relatively low
total hardness; according to T. E. Larson,
Illinois Water Survey, these waters are
among the softest surface waters in IIli-
nois.
Under the crop rotation systems fol-
lowed by University of Illinois agron-
omists at the Dixon Springs Experiment
Station, the fields surrounding the ponds
were kept in pasture most of the time.
New rotations were begun on the water-
shed of each of these ponds within the
Table 2.—Water temperature (in degrees F.) measured at 2-foot intervals and on bottom
period of the study: Phelps in 1948,
Hooker in 1949, Wells and Lauderdale
in 1950, Boaz (east half) in 1949, Boaz
(west half) in 1951, and Elam in 1952.
In each pasture reseeding, winter wheat
or rye was planted with various grasses
in the fall of the year, while legumes
were broadcast the following spring. Corn
was planted in the spring prior to the
fall seeding on the Boaz west field in 1951
and on the Elam watershed in 1952.
Until dense pasture growth was re-
established, silt from the fields was
washed into the ponds after each hard
rain. Silting occurred even though grass
buffer strips surrounded the ponds.
The Dixon Springs Experiment Station
lies in an unglaciated region where the
in the six Dixon Springs ponds, August 12-14, 1947.
| LAUDERDALE Hooker PHELPS WELLS Boaz ELam
DEPTH IN (DeptTH 8 (DeptuH 10 (DeptuH 5 (DeptH 10 | (Depro 84%) (DepTH 6
Feet Feet)* FeeET)* FeeT)* Feer)* Feet)* Feet)*
Avucust 12 | Aucust 12 | Aucust 13 | Aucusr 12 | Aucust 13 | Aucust 14
Surface....... 89.2 558 ode ees 87.1.5 |e Beee 83.1
LP Saki SE fe ae 84.6 83.1 83.1 85.6 82.0 83.1
is aan eee ey 83.1 82.8 81.7 84.9 Var 84.24
pe eee TET SOEG: ics eer 75.6 66.9 82.4
ee ae 72.0 p57 Mario Wi Peete eer a Ves 64.8 ol)
Bottom...... 72.0 68.0 78.4 68.7 64.4 82.4
——e ee
*Depth of water at point of temperature readings, not necessarily the greatest depth in the pond at the time. The —
bottom reading is for this depth.
reading for Hooker is for a depth of 10 feet.
7This figure probably represents an error in recording.
Examples: The bottom reading for Lauderdale is for a depth of 8 feet; the bottom
August, 1960 HANSEN et al.: Hook-ANp-LiINE CATCH
71g. 3.—Aerial view of Phelps Pond, 1.04 acres, October, 1950. Exposed mud flats resulting
from loss of water may be seen around the margin of the pond.
Fig. 4.— Aerial view of Wells Pond, 0.97 acre, October, 1950. The cypress trees in the
water and the pines in the fenced area surrounding the pond had been planted.
350
I-ttinois NaturAL History SurveEY BULLETIN
Vol. 27, Art. 5
Table 3.—Mineral composition (parts per million) of water collected from the six Dixon
Springs ponds on March 19, 1947, prior to fertilization.
MINERAL povaeen Hooker* | PHELPs* WELLS Boaz ELam
Iron—filtered............. 0.3 0.3 0.6 0.3 bey 0.7
Iron—unfiltered...........| 0.6 0.4 ily a! 0.5 2.8 1.0
Phosphate fai Ui gaa stuart Or? Oz 0.2 0.3 0.8 0.6
Galcivuin dna see eee 8.1 6.0 8.8 6.6 7.0 7.6
Mapheetti occ oe nn bee oi L3 0.2 0.4 0.0 0.0 0.0
Sodium and potassium..... 1.8 4.6 0.0 0.9 4.4 3.4
Sulfate ss cievc node law UE? 10.5 8.2 7.0 12.3 10.1
Nitrate rd. fia tts Sates ae 1.0 0.4 0.5 0.5 2.0 0.8
Ghloridess2. ues eae 1.0 5.0 2.0 2.0 3.0 3.0
Methyl orange alkalinity... 16.0 8.0 12.4 8.0 9.0 12.0
Totaljhardnessiae sates 26.0 16.0 24.0 16.0 18.0 19.0
*Pond selected for fertilization. ‘
+As orthophosphate PO, (includes organic phosphorus).
tIncludes N in the form of ammonia and nitrate but not in the form of nitrite or as organic nitrogen,
terrain is a mixture of gently rolling land
and steep hills. Numerous sandstone out-
crops are present. The region was com-
pletely forested at the time of settlement,
and considerable woodland still exists.
During the many decades in which the
cleared land was used extensively for
growing corn and wheat, most of the
slopes suffered from erosion. With the re-
cent trend toward permanent pastures or
crop rotations that include pasture, the
rate of erosion on slopes has been greatly
retarded.
The level of productivity of a fish pond
and its capacity for providing good fishing
are generally assumed to be determined to
a great extent by the level of plant nu-
trients in the soils of the pond bottom and
of the watershed. In common with soils
over most of Pope County, those at the
Experiment Station have low natural fer-
tility. Recent tests of soils in Pope and
Hardin counties showed 96 per cent of
the samples deficient in available phos-
phorus (Thor & Jacob 1955). The soils
on the watersheds of the ponds used in the
pond fertilization study belong to two soil
types. Grantsburg silt loam covers the
hilltops and lesser slopes, and Manitou
silt loam covers the steeper slopes ( Fehren-
bacher 1959).
These soil types, which are closely re-
lated, are described by Fehrenbacher
(1959) as grayish yellow or brownish
Table 4.—Available phosphorus and potassium (as pounds per acre in the upper 6 2/3
inches of soil) and the pH of soils of the fields draining into four of the six Dixon Springs
ponds. The ratings, such as “high,” are based on a system used by the University of Illinois
Soil Testing Laboratory.
one or| Most Recent YEAR Pounps Per Acre
COND oF Soi, TREATMENT Date or SoiL S : ai H
WaTeER- | PrecepinG Soi Test* as eae Available Available P
SHED Phosphorus | Potassium
Phelps... . 1948 January 6, 1957 66 ae 187 (High) 6.3
to high)
Wells..... 1952 February 10, 1956 84 (High) 110 (Slight) 6.2
Boazt.....| 1936 August 14, 1951 10 (Very | 265 (Very 6.0
low) high)
Flam) sc 1952t August 8, 1952 rad ais 95 (Slight) 559
ow)
*Kinds and amounts of fertilizer materials used are shown in table 5.
+The soil test was made on the west half of the Boaz watershed.
Spring.
August, 1960 HANSEN et al.: HooK-AND-LINE CaTCcH 351
Fig. 6.—Aerial view of Elam Pond, 1.55 acres, October, 1950.
352
gray silt loams, which, if untreated, are
strongly acid, low to very low in avail-
able phosphorus, low to medium in avail-
able potassium, and low in organic mat-
ter. University of Illinois agronomists
have found that in order to farm these
soils at a profit it is generally necessary to
treat them with crushed limestone and
with either rock phosphate or superphos-
phate. They have also found that it may
be profitable to use complete fertilizers on
seed beds and as top dressing on poorly
growing pastures.
Iturnoris NaturAL History SurveEY BULLETIN
Vol..27;. Art. 5
Soil tests were available for the fields
draining into four of the six experimental
ponds, table +; tests were not available for
the other two fields. The fact that the
soil tests on these fields show only slight
acidity and that some of them show high
amounts of available phosphorus and po-
tassium is explained by the soil treatments
made in connection with field crop studies.
applied in the period 1935-1953 to the
fields draining into the six ponds. Prior
to the soil tests recorded in table 4, all of
.
Table 5.—Soil treatment dates and materials (in pounds per acre) applied to the fields
draining into the six Dixon Springs ponds. The east and west halves of Hooker and Boaz
watersheds were treated separately. The manner of treatment, where known, is indicated by a
letter.* The watershed area indicated for each pond includes pasture but not woodland.
J
|
i
Table 5 is a record of all soil treatments |
|
—— SEE
SUPERPHOSPHATE | £ mn Compcere Ferrinizer | :
3 = >a
oder z
WaTERSHED Date OF Pi ee oe as Z |, sa
NAME AND SoIL S rs 3V | 00 ou
vo oO - = :
AREA TREATMENT S 75a a ©) a 2 = Ph pate ae o “a
3 | 4f|2|818|gelzel a | Geo
& eae om | | $0 | PO] = = a oo & 4
a me el Gand cee abs a | | an | o | Rae
Lauderdale, {1937 SQO0THIESS -ealesee 200 9)... ve ete |. nee oD ee ;
5 acres 1950 (fall)t 6, 000M|12000M100 BD) .pan4\oue oc lect Gs acral eis eee 180 ||... 5.3)
O52 iGsyoranne) holy, asst oli agaoe ec [ees oe | eel ees (NCO TO) Bal fe retire toed: 100T |... | =e
(oe € 2 Ds Be ee eg er RIO CAL 8 SSN BE | Ae LOOM | easier LOOT: | 2°S5\20 eee F
1953 (eprint raileccar meal Boer aero 15 OMe Been 1S0T |). .:..|).5) sel :
Hooker, 1935 8,000T |... -.c)ceeus|ee cs -|egee chess melee cache. colo neal ae :
east half, {1949 (fall)t [8;000M|1,000M|.....|.....].....].....|...--[o...0le oso elfen nnn
9=10: Bete L953 KSPHANB) es xcs oen shia owl ee ose ae eal ee nT es eee ie aa 200T |... s.\0<oee| en ‘i
Hooker, + 1946-1948+ EAS) ore a tear ae AO ae oS eet ree ae Oe 200 D|: : 2.2): oe) ae :
west half, -/1949 (spring). |... 4..| 2.085. CBr ep este el feiearoee a ee A Aste nia Pt |... a
oe (URE Tes eli he fol ad HD etc ala ie San bo etna Mle Wow oe On Ra DI tel lan a 200 D) -.:)2 55 soe) eee bY
Phelps, 1937 8 OOOT i te eu) ec airs Oa oaks elles aleve [tea tite [o eel eee et ee rrr
5 acres 1948 (fall)t 8,000MIG00M fo. fee Shee en 21s ae ID ce s
Wells, 1937 (fall) TOOOI AS toe te |g 710) 0) ee PR (I eet i
3-5 acres |1950 (fall) tf 8, 000MAT 000M) 2 ech. ar euctox 2) eee fee 350D 4
Eom (Ty ais Pierre ipa earitaee prea hack Pieced SR 200T |... .|0. ann i
Boaz, east _|1936 780 bal cee Ma %
half, 4-5 = |1949 (fall)t 8,000M|1, 000M]... 2 ..]5....[6..5.).0. lees 8 i. oer 4
acres 1953 (spring) Setar ree | hae eck al Pagers 1300s eee 43T ho...) 02. | eae F
Boaz, west /|1936 S2000T tsar laa ier al
half, 4-5 {1951 (spring)**|4,000M|1,000M).-...|.....}.....].....]0...5|. 2 «|. pent f
acres 1951 (fall)** |8;000M|1,000M|.....|..... 100'Dh.co.| See 100 D i.
1953 (spring) Er et |i een mse 200 T ee
Elam, 1936 SOOO. eae wid eek 200 1-0. Seale
6-7 acres 1952 (spring)t |6,000M|1,000M|.....|.....|.....|....-|..-..|.... eles e-lec ee. 200 {8,000
O52: Cha P50 ycoscs ea alec east eee abe Rae heehee ee 200 D).. . . «cent ae ;
*The letter following quantity signifies manner of application, where known: T = top dressing; M = mixed with R
upper 4 to 6 inches of soil; D = drilled with seed 1 or 2 inches below soil surface. oy
7The west half of the Hooker watershed is privately owned; the record of fertilization was based on the owner’s 5
memory. The soil had probably been treated with limestone, according to the owner, at some time within the period
1946-1948. Treatment with fertilizer was made in the spring of 1949 and consisted of 100 pounds per acre of either a
superphosphate or 2-12-6 applied with a seed drill. a
At time of reseeding of field.
**Limestone and rock phosphate applied to part of west half of Boaz in spring and to remainder of west half
in fall.
iw en
ce
Ce
August, 1960
the pond watersheds had been treated
with crushed limestone to reduce acidity ;
three watersheds, Phelps, Wells, and
Elam, had been treated with phosphate.
The west half of Boaz had not been
treated with phosphate at the time of the
soil test. The phosphate treatment on the
Elam watershed was made a few months
before the soil test, but the phosphate had
not yet become well mixed with the soil.
The Wells and Elam watersheds had been
treated with potassium through applica-
tions of complete fertilizer a few months
before the soil tests.
EXPERIMENTAL
PROCEDURES
Each of the six Dixon Springs ponds
used in the fertilization study was stocked
at the beginning of the experiment with
known numbers of bass and_bluegills.
Chemical fertilizers were added to three
HANSEN et al.: HooK-AND-LINE CatTcH 353
May, 1946; Hooker (fertilized), Phelps
(fertilized), Boaz (control), and Elam
(control) in September of the same year.
Stocking the Ponds
The rates at which the Dixon Springs
ponds were stocked with bass and bluegills
were close approximations of the rates sug-
gested by Swingle & Smith (1942:13)
for ponds in Alabama; these authors rec-
ommended 100 bass and 1,500 bluegill
fingerlings per acre in ponds that were to
be fertilized, 30 bass and 400 bluegill
fingerlings per acre in ponds that were not
to be fertilized. The actual numbers of
fish used in the Dixon Springs ponds and
the per-acre rates, based on area of the
ponds at full stage, are given in table 6.
On the basis of reduced late summer water
areas of these ponds, the stocking rates
were of course higher than those shown.
The ponds were stocked between Oc-
tober 30 and November 9, 1946. The
Table 6.—Number of largemouth bass and bluegills, and number of fish per acre, released
in the six Dixon Springs ponds October 30-November 9, 1946. The bass measured 6.0 to 10.0
inches, the bluegills 1.0 inch, at the time of release.
LarGcemMoutH Bass BLUEGILLS
Ponp (WirH Surrace AREAS
IN AcrES) Total Number Total Number
Number Per Acre Number Per Acre
FERTILIZED
Meemicderdale’ (O92) \o cc. soe Heceres « 100 109 1,500 1,630
iol ee 118 89 1,500 1.197
Smeal O4).. Pi. Ee: 95 91 1,300 1250)
UNFERTILIZED
Nellis (OSS ip aang Oats en 35 36 400 412
Evsieya: (CURA O10) eee are tee a 30 30 400 396
Eleva (CSO) ae eae ee oe aa 3s 21 480 310
of the ponds, Lauderdale, Hooker, and
Phelps. The other three, Wells, Elam,
and Boaz, were maintained as controls.
Records were kept of the stocking rates,
the times and rates of fertilization, the
numbers of hours of fishing, and the num-
bers and weights of fish caught in each of
the ponds.
Fish populations that were in the six
ponds previous to the beginning of the
experiment had been eliminated by ro-
tenone treatment 2 to 6 months before the
experimental stocking was done: Lauder-
dale (fertilized) and Wells (control) in
largemouth bass used for stocking were 6
to 10 inches long (total length) and
bluegills were all about 1 inch long. All
fish used in stocking had been collected
from nearby Lake Glendale during the
draining of the lake in October, 1946.
Other bass of 9 to 10 inches obtained
from Lake Glendale during the draining
operation were found, when aged by scale
examination, to be in their third, fourth,
fifth, or possibly sixth years. The 9- to
10-inch bass in their fifth or sixth years
were considered somewhat stunted. It is
assumed that the 1-inch bluegills and 6-
w
wn
rs
Table 7.Fertilization record of Lauderdale, Hooker, and Phelps ponds, showing dates of application, number of treatments per year, and per-acre
rates of application of chemical fertilizers and ground limestone.
Hooker (1.33 Acres) Pre cps (1.04 Acres)
LAUDERDALE (0.92 Acre)
Pounds Per Acre at Each
Treatment
Lime-
stone
ILttino1is NATURAL
Chemica! Fertilizer*
ments
Treatment
stone
Pounds Per Acre at Each
Treatment
Chemical Fertilizer*
100 (9.0-13.6-2.8)
100 (9.0-13.6-2.8)
Number
of
Treat-
ments
wt ot tC 00 CO CO
PERIOD OF
TREATMENT
May 26-Sept. 13 f
May 10-July 30
April 11—Aug. 11
May 13-Sept. 14
April 18-Aug. 16
April 17-Aug. 8
May 13-July 23
YEAR
1947...
1948
1949...
195055...
LOSI:
1952
1953...
pounds of material ap-
hate and muriate of potash.
20 in 100
lied by superphosp
and potassium as K
phosphorus as P,Os,
Phosphorus and potassium were supp
ds of nitrogen as N,
or ammonium nitrate (1950-1953).
September 13; Phelps, July 19.
the N-P-K formula or poun
August 11; Phelps, July 14.
1949)
; Hooker,
ncluding fillers. In parentheses:
monium sulfate (1947—
n 1947: Lauderdale, July 25
n 1950: Lauderdale and Hooker,
ed by am
*Weight of fertilizer i
Nitrogen was suppl
+Last treatment dates
tLast treatment dates
plied.
History Survey BULLETIN
Vol. 27, Art. 5
inch bass were hatched in 1946. Green
sunfish that later were caught occasionally
in two of the ponds, Phelps and Boaz,
may have been placed there accidentally
with the 1-inch bluegills. The sizes of the
fish used were the sizes most readily avail-
able from Lake Glendale. Whereas
Swingle & Smith (1942:13) suggested the
use of fingerling bass and bluegills where
both species were to be used in stocking |
in the fall of the year, we departed from
their recommendation by using small adult
bass as well as bass fingerlings.
Each of the largemouth bass placed in
the ponds was marked by removal of a
pectoral fin clipped close to the body; the
bluegills were not marked.
Fertilizing the Ponds
Chemical fertilizers, which contained
nitrogen, phosphorus, and potassium (N-
P-K), were applied to Lauderdale, Hook-
er, and Phelps each year, 1947-1953; no
fertilizer was used in Wells, Boaz, or
Elam.
Numbers of treatments, periods of
treatments in different years, and N-P-K
formulas are given in table 7. In terms
of the number of treatments given and
total quantity of nitrogen, phosphorus,
and potassium introduced during any
single year, fertilization was lighter dur-_
ing the first 3 years than during the last
4, except that in 1950 the quantity of
phosphorus applied to Phelps was slightly
less than was applied in any of the previ-
ous 3 years. As recommended by Swingle
& Smith (1942:16), crushed limestone
was used in addition to the nitrogen,
phosphorus, and potassium fertilizers when
ammonium sulfate was used to supply
nitrogen (1947-1949). It was intended
that the three ponds to be fertilized should
be dosed at the same rates. Dosages ap-
plied were computed from areas obtained
from the best maps available in 1947.
When the ponds were mapped by plane
table in 1951, the maps that had been used
were found to contain errors. These er-
rors account for the different amounts of
N-P-K applied to the three ponds in the
years previous to 1953, table 7.
The methods of treating the three fer-
tilized ponds in the Dixon Springs experi-
ment were similar to those described by
Swingle & Smith (1942:16-8). These
August, 1960
authors recommended a formula for the
amount of fertilizer to be used at each
application but allowed for considerable
flexibility in the number of applications to
be given within a year. The N-P-K
formula used in the ponds at Dixon
Springs in 1947-1949 was similar to, but
was heavier in phosphorus than, the one
described by Swingle & Smith. The dos-
age rate used at Dixon Springs in 1950-
1953 was a still closer approximation of
the Swingle & Smith rate. The Swingle
& Smith technique of dosing ponds as
often as necessary to maintain blooms of
plankton algae was followed only in 1950.
Numbers of applications in other years
(four per year in the period 1947-1949
and eight per year in the period 1951-—
1953) were selected arbitrarily. The
Swingle & Smith recommendation that
fertilization be delayed in the spring until
danger of overflow is past, usually April
or May in Alabama, could not easily be
followed at Dixon Springs, where rains
heavy enough to cause overflow of the
ponds often occur as late as June or July.
Dosages were based on pond areas at
full stage and were not reduced when
pond areas shrank in midsummer. No
attempt was made to replace fertilizer
losses which may have occurred through
overflow of water.
The chemical compounds used as sources
of nitrogen, phosphorus, and potassium
Were ammonium sulfate (or nitrate), su-
perphosphate, and muriate of potash.
These compounds were weighed separately
as needed, then mixed, and broadcast into
the shallow water along the shore of each
of the three ponds selected for fertiliza-
tion; most of the fertilizer fell where the
water was 2 to 4 feet deep. Distribution
of fertilizer was always made around the
entire pond.
When the ponds were treated only four
times a year (1947-1949) the individual
treatments were usually spaced 2 to 4
weeks apart. Treatments were postponed
if blooms of algae were so dense as to
obscure the Secchi disc at a depth of 24
inches or less.
They were postponed in 1947, also, dur-
ing the period of decay of aquatic plants
(mainly Chara spp.) that had been killed
by earlier treatments. When the ponds
were treated eight times a year (1951-
HANSEN et al.: HooK-AND-LINE CatcH
355
1953) many of the treatments were given
at l-week intervals, without regard to the
density of the blooms, or to the transpar-
ency of the water, as measured by the
depth at which a Secchi disc was visible.
There was no indication that these closely
spaced treatments had any adverse effect
upon the fish populations; dead fish were
not reported in any of the ponds.
Collecting Fishing Data
Creel data were obtained through con-
trolled public fishing and through test
fishing by Illinois Natural History Sur-
vey employees. Since two of the ponds—
Lauderdale and Wells—were fished al-
most exclusively by the test anglers and
since certain data presented here from all
six ponds were gathered entirely by the
test anglers, it is appropriate to describe
test fishing routines in some detail.
At least one test angler fished each
pond once a week from early June to
early September, or about 12 times a sum-
mer. Occasionally one of the test anglers
was joined by another fisherman, usually
a fellow staff member. The test angler
fished one fertilized pond and one control
pond on each fishing day; Lauderdale was
paired with Wells, Hooker with Boaz,
and Phelps with Elam. Each pond was
fished alternately in the morning of one
week and the afternoon of the following
week. The senior author of this paper, as
well as the regular test angler, fished the
six ponds throughout the summers of 1948
and 1949. In the other years of the ex-
periment the test fishing was done prin-
cipally by one man.
Ordinarily a test angler fished the ponds
for 2 hours on each visit, spending about
1 hour fishing with fly rod and/or casting
rod with artificial baits and | hour fishing
with fly rod and natural baits, usually
worms.
All captured fish were placed on string-
ers until the end of the 2-hour fishing
period; then each fish was measured and
weighed. Bass measuring 10.0 inches (total
length) or longer and bluegills measuring
6.0 inches (total length) or longer were
kept; the others were returned to the
pond. Considerable mortality occurred in
hot weather, notably among small fish.
The fish caught by the test anglers
were measured to the nearest tenth of an
356
inch and they were weighed to the nearest
4-gram interval on a John Chatillon &
Sons 1,000-gram spring scale. The weights
were later converted to pounds.
Public fishing was allowed in four of
the ponds, Hooker, Phelps, Boaz, and
Elam, under a special permit system. A
grocery in Glendale and the Lake Glen-
dale bathhouse were used as permit sta-
tions. Fishermen were allowed to fish in
Lauderdale and Wells if they accom-
panied the test anglers on regularly sched-
uled trips; few permit fishermen took
advantage of this arrangement. Lauder-
dale and Wells were excluded as regular
permit ponds in order to be assured of an
equal or nearly equal amount of fishing
time on one fertilized pond and one con-
trol pond. Under the now widely used
permit system, each fisherman selected the
pond where he wished to fish and was
issued a 1-day permit for that pond in ex-
change for his state fishing license. At the
end of his period of angling the fisherman
submitted his fish for counting and weigh-
ing and recovered his state fishing license.
Information recorded for each permit fish-
ing period included time spent, types of
baits used (plugs, flies, worms), and, for
each species of fish, weight of the fish
kept and an estimate of the number
thrown back. The fish caught by the per-
mit fishermen were not measured or
weighed individually.
One boat was kept on each pond for use
by test anglers and permit fishermen.
Fishermen supplied their own oars or
sculling paddles. The use of minnows for
bait was prohibited in order to guard
against contamination of the ponds with
unwanted species. Earthworms or catalpa
worms were by far the most popular baits
used by permit fishermen; plugs were next
in popularity.
Throughout the experiment, anglers
were limited by state law to 10 bass a day;
they were also limited to 50 bluegills a
day until that limit was removed on July
1, 1951. These creel limits were seldom
approached by either the test anglers or
the permit fishermen. A 10-inch legal
size limit on bass was in force throughout
the state until July 1, 1951. People fish-
ing on the six Dixon Springs ponds were
asked to continue observing the 10-inch
limit until termination of the experiment.
ILLtinotis NATURAL History SURVEY BULLETIN
Vol. 27, Art. 5
‘The ponds were open to fishing each day
from 6 A.M. to 9 p.m., May 15 through
the first Monday in September.
The permit fishermen were not in-
formed as to which ponds were treated
with fertilizer, nor were they often re-
minded that a test of pond fertilization
Was in progress.
Although fishing regulations were
posted at each pond there were some
violations, including poaching.
Censusing the Fish Populations
In order to determine the standing
crops of fish (numbers and weights) in
the Dixon Springs ponds, we killed the
fish with rotenone and censused the popu-
lations in the period September 8-17,
1953.
Cube powder (5 per cent rotenone con-
tent) was applied to the ponds at the rate
of 3 pounds of powder per acre-foot of
water. Fish were collected, counted, and
weighed on the day the rotenone was in-
troduced and on each of the succeeding
three days. Because insignificant numbers
of fish were found on the fourth day after
treatment, no counts were made on that
day or later.
POND FERTILIZATION AND
PLANT LIFE
The use of chemical fertilizers in the
Dixon Springs ponds resulted in increased
abundance of plankton algae in each of
the treated ponds and in periodic heavy
growths of filamentous algae, particularly
in one pond. The fertilization program
aveaesal
was detrimental to the growth of rooted
aquatics.
Blooms of plankton algae, similar to
those described by Swingle & Smith
(1942), appeared in the fertilized ponds
each year. The blooms occurred after two
to four applications of fertilizer. The
number of treatments required to produce
these blooms varied with the pond and the
vear. Blooms were much heavier in some
years than others. They were light at
Lauderdale, for example, in 1950 and
1951. The effect of blooms on water
transparency may be seen in table 8. Light
blooms were sometimes observed in the
control ponds but these blooms seldom
lasted for more than 1 week at a time.
'
August, 1960
Once the blooms were established in the
fertilized ponds they lasted as long as 2 to
8 weeks without further additions of ferti-
lizer. When a bloom began to disappear,
an additional application of fertilizer
usually resulted in an increase in its den-
sity within 1 or 2 days. Ball & Tanner
(1951:9) found that in North Twin
Lake, Michigan, an increase in plankton
followed each application of fertilizer.
In the Dixon Springs ponds, surface
growths of filamentous algae—probably
stimulated by the pond treatments—were
a hindrance to fishing in some years, but
perhaps did not seriously affect fish yields
or catch rates. Such growths were present
in all three fertilized ponds in the summer
of 1947, the first year in which fertilizer
HANSEN et al.: HooK-AND-LINE CATCH
357
was used, and were especially heavy at
Lauderdale Pond in the summers of 1948,
1950, and 1951. At various times during
these 3 years filamentous algae covered
25 to 75 per cent of the surface of Lauder-
dale Pond, fig. 7. Anglers sometimes had
to clear away algae before fishing their
favorite spots. However, Lauderdale pro-
duced by far the best fishing in spite
of this growth of filamentous algae. Sur-
face growths were sometimes observed on
the control ponds, but they covered only
small areas and were present for only
very short periods. The floating algae on
Lauderdale was identified as Rhizoclon-
ium sp.
Heavy growths of filamentous algae in
chemically fertilized ponds have been re-
Table 8.—Average depths (in inches) at which a Secchi disc was visible below the surface
of each of the six Dixon Springs ponds (weekly observations averaged by months), monthly
averages for fertilized and for unfertilized ponds, and differences between monthly averages.
The lower transparency of the fertilized ponds generally resulted from blooms of plankton algae.
| DIFFERENCE BETWEEN
Bes aa FERTILIZED UNFERTILIZED pas aoe
ie ; | A Fertil U lized
Aver- | yy ver- tilized nfertiliz
Lauderdale |Hooker|Phelps ase Wells | Boaz | Elam ee: ee eine
— |
1947 |
June*.. 56 lke pt liar eres © 56 G6 Wiese ee eee Bs Kiar estar a PG al leona tine a oP ee
Nicllys a. 51 33 byl 45 41 11 62 38 Toy ae Meee ee
August. 15 1) Sie ero 36 6t | 63 SSO Pape ents. Cae 19
1948
June... 17 26 25 23 31 16 30 TAO Nae See cee eRe ey
july... 7 21 22 20 37 20 31 29 ee ee 9
August. 20 16 18 18 25 Dal 29 ayes |\eo tet eae f Hl
1949
June... 30 21 DS 25: 37, 33 30 SBI henge Sere 8
iliulligrs 14 20 19 18 39 35 33 3 Ole een ee 18
August. py) 19 12 18 39 35 36 SH |e teres calcu 19
1950
June... 39 13 16 22 28 28 33 C3 al | camseeeee eke 8
Nialiy.ces.. 34 12 11 19 29 39 36 35 ee Sees 16
August. 58t 15 12 28 30 36 38 CEeN tone eee 7
1951 |
June... 14 39 14 22 26 23 38 AN 2 ann Se rook 7
july. =. 35 33 20 29 50 35 42 pO Ares a ewe oe 13
August. 43 De 13 28 20 48 SG eres Wee eee 13
1952
ne: . - i) 113! ae ae 31 44 39 38 aA A ee DF;
July... .| 14 12 ie hes} 14 40 a2 25 apes Tew es 12
August. 11 19 ONG ih shes} 16 39 | 20 DG Pelee: semen Ney. 12
*Readings were begun late in the month. A single reading at Hooker was recorded as “‘very clear.’ A single
reading at Elam was recorded as 38 inches;
be found.
The reading was 108 inches at Lauderdale Pond on August
time in any of the six ponds.
no readings were made at Phelps or 7
+The low readings at Boaz in 1947 were the result of nearly continuous muddiness,
Boaz during June.
for which no cause could
7
27, 1950. This was the highest reading made at any
w
an
ie 2)
= ee <a
sere
Ittrnois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 5
Fig. 7—Lauderdale Pond, August, 1950, with surface partially covered with a growth of
filamentous algae, after the pond had been fertilized.
ported by Patriarche & Ball (1949 :29)
in southern Michigan, by Surber (1945:
388) in West Virginia, by Zeller (1953:
286) in Missouri, and by Smith & Swingle
(1942) in Alabama.
Bottom-inhabiting filamentous algae
(unidentified) were sometimes present in
both fertilized and unfertilized ponds at
Dixon Springs, but usually for only brief
periods. However, such algae were found
to be a nuisance to fishermen at Lauder-
dale throughout the summer of 1952.
Dense stands of Chara in the three fer-
tilized ponds died in 1947, after three
fertilizer applications; for as long as fer-
tilizer was used (from the spring of 1947
through the summer of 1953) this plant
remained extremely scarce. Chara nearly
covered the bottoms of the three control
ponds throughout the study. An increase
in abundance of Chara was seen in Lauder-
dale, Hooker, and Phelps during 1954
and 1955, the first years after 1947 i
which no fertilizer was used ; however, in
1956 Chara had still not regained its
prefertilization abundance.
The disappearance of submerged weeds
in ponds treated with chemical fertilizers
was observed by Swingle & Smith (1942).
These authors recommended winter fer-
tilization to destroy undesirable sub-
merged aquatic plants and periodic fer-
tilization to prevent their re-establishment.
Surber (1948a) reported that a variety of
rooted aquatic plants had been killed after
use of a chemical fertilizer at Deer Lake,
New Jersey. Ball & Tanner (1951: 11)
found that chemical fertilizer all but
destroyed Chara and Potamogeton in
North Twin Lake, Michigan, but that
each returned to its former abundance the
year following termination of fertilization
of the lake.
POND FERTILIZATION AND
FISHING SUCCESS
The pond fertilization program at
Dixon Springs can be evaluated by com-
paring the three fertilized ponds, Lauder-
dale, Hooker, and Phelps, with the three
control or unfertilized ponds, Wells,
August, 1960 HANSEN et al.: HooK-AND-LINE CatTCH 359
Table 9.—Numbers of largemouth bass, in various length classes, caught by Illinois Nat-
ural History Survey test anglers in three fertilized ponds at Dixon Springs. Bass of less than
10 inches in length were returned to the water. Numerals in boldface type represent bass (marked
by fin removal) used in stocking the ponds.
LENGTH LAUDERDALE Hooker PHELPS
Crass, a a EE
IncHes* |1947/1948/1949|1950|1951 |1952|1947|1948]1949/1950/1951|1952| 1947/1948 1949/1950 1951/1952
NNe
=
a |
nn
—
ReWN
nN
NwWoOn Ww
=
Yo Te
o
ONE RENNES
—
i=)
So
—"
ore)
KSHNOe
PAOD W =
iS
SK OnORN BNE
mb WR SOT
NSO
NAWO~WOSOPR RNY
—
BNW OANRNN HNN WwW
PNNH AIH
—
i=)
Leal
NWN S WS Oe
rm WD
Qe PDH no
Mame .| 09 | 23 | 341) 57.) 26 | 39 | 25. | 22 | 60 | 40) 52) 17 | 28 | 26 | 43 | § | 8 | 4
inch
class or
eet SUn bts toh Soel 13) 30 Fel Oe Sob ON 2a OF ey TG) FAIS) | 1G <8
Average
length
of fish,
10-inch
class or
larger. .)10.8/11.7/11.4|11.4/11.7/12.0/10.6]10.9]10.4/10.1/10.6]. .. ./10.0)10.2)10.3}10.8/11.7}12.0
Per cent
in 10-
inch
class or
larger. .| 72 | 48 | 474,58 | 50 | 77 | 28 |. 41 88123 |-46e) O14 | GL he 38575. 29
*Each number designating inches represents the mid-point in a length class; for example, the number 4.5 includes
the bass of 4.3—4.7 inches total length.
360 ILttinots NaturAL History Survey BULLETIN Volo 2/aAnte a
Table 10.—Numbers of largemouth bass, in various length classes, caught by Illinois Nat-
ural History Survey test anglers in three unfertilized ponds at Dixon Springs. Bass of less than
10 inches in length were returned to the water. Numerals in boldface type represent bass
(marked by fin removal) used in stocking the ponds.
Lexcrs WELLS Boaz ELam
CLass a tl i ca ie GG EA Gin ack cakiaeut oo
> |
IncHEs* 1947/1948 1949 1950)1951)1952|1947/1948)1949|1950)1951|1952/1947|1948)1949|1950)1951,1952
vn
o
—
—
et
—_
—
_
tw
NrWwWhH
=
Ww
in
—
RNR Roe
o
mWnIOnNI OO NWN
=
mr he SI I
NN Nee
— er OO en to ni nn in
aAnhe
Teen
NU —_
DEKH NOO oppoa-—
DP ~100W WROD nn
i) PrmWOL Lhe
—
RNR POW RD Ww
_—
—
nN ANDDWUNN
—e— pe ee —_
Nr
KSNN RRR hee
—_—
_—
_
w&
o
Nw
RNR WON NN
— tt
—
wn
nn
_
Total.) 5%: 15 | 50 | 44 | 20 | 19 | 22 | 91 12 | 30 | 34|-16 | 13 | 8 | 43 | 71) 50) 360m
class or
laren. |) boo) lt See? e| 16 eel 8 4 Daal. 7 9 8 5 9 | 18 | 20 |e
Average
length
of fish
10-inch
class or
larger . .|11.1/12.4/11.2/11.2/11.7/12.1/10.6/13.0]10.3/11.0/11.2/11.3]11.0/11.5/11.9/10.6]10.7|11.8
Per cent
in 10-
inch
class or
larger ..| 100} 22 | 34 | 60 | 84 | 77 | 89 | 33 7 | 35 | 44 | 69 |100 | 12 | 13 | 36 | 56 | 57
*Each number designating inches represents the mid-point in a length class; for example, the number 5.0 includes
the bass of 4.8-5.2 inches total length.
August, 1960
Boaz, and Elam, with respect to the sizes
of fish caught, the annual fish yields, and
the catches per fisherman-hour.
Sizes of Fish Caught
Length distributions of all bass and all
bluegills caught by the test anglers are
shown for the six ponds in tables 9, 10,
12, and 13; these tabulations include the
HANSEN et al.: HooK-AND-LINE CatcH
361
bass under 10 inches and the bluegills un-
der 6 inches that were put back in the
ponds after measurement. The average
weights of fish caught and kept by test
anglers and permit fishermen are shown
in tables 11 and 14; lengths of fish caught
by permit fishermen were not recorded.
Few of the bass caught by test anglers
measured more than 13 inches; the only
Table 11.—Average weights (in pounds) of individual largemouth bass harvested by hook
and line from each of the Dixon Springs ponds in each of 6 years. Data from which the figures
were derived are in table 20.
Ponp 1947 1948 1949 1950 1951 1952 AVERAGE
FERTILIZED
Lauderdale. ... 0.60 0.71 ()sSi7/ 0.68 0.83 0.70 0.68
looker... .... 0.63* O72} 0.63 0.60 0.63 0.53 0.62
Phelips® 4: <-- 0.50* 0.43 0.50* 0.53 0.71 0.75 0.57
eerste mT ed a Tec (ce7aTS 5) Foc |. 0 Sra se theta pea amet ReR ES ls ts iw eee simvocen eae er Retr = 0.62
UNFERTILIZED
Wellse 2 oles: OF73 0.92 0.63 OE 7Al 0.68 0.92 OL77
Boaz 0.67* il aails} 0.57 0.58 0.64 0.83 0.74
[EIGN Rare ene 0.63* 0.64 0.91 0.64 0.72 0.74 0.71
JECTED 0, 0 6 3,04 OND SOB OM |e Cae eee ee | RRR 7 bl eric nena Pe (earn teres co | Gitano 0.74
*Average based on fewer than 10 specimens, as shown in table 20.
Table 12.—Numbers of bluegills, in various length classes, caught by Illinois Natural
History Survey test anglers in three fertilized ponds at Dixon Springs. Bluegills of less than 6
inches in length were returned to the water.
LAUDERDALE Hooker PHELPS
LencTH Crass, INcHEs* ae
1948|1949 1950,1951,1952)1948 1949 1950 1951/1952 1948 19491950 1951 1952
0). seo RE ee eee Spr Be alii
L3.cosge eee eee iyi: 1 eee ae 1 ae bore (Pe Dies ee
10: ie ree 1 he sce Dee lnc ea he 1 1 a (e ieee A | 6
Scot ee (WC A751 SiS) TS) ee AS eae el el ce Tie as
_ |e SAS Po J gis 5 ll! 4 pA ailing? | RIES in! og 1 er ee 5
0 RES ee Gi By 27) 9 AA. Gln ed 2 ee |e eet |
Le cs eee eee 19 9; 40 5 6 1 2 Zl 4 2 2 g 3) 10] 16
ee Ga tat 27) 16) “19 Fi Si MONS 2a te ee SS 2 ts
” (0), oct Been ee sae 2025) 17) 30) 43" 19 5 Sie Lie 20a! 4) 12 8
ee MG ole SS| 37), 40) 6 Si 91 ellie <4 heer. AED Ae A 47,
ao OS is tA 22 | 22 ee Sle Si yee set. Ni Se 4)
|. See ee OR | lta 11) Vas YE (ae SS Pcie Crees) ea ares Lets ocd oe cecil tetanre Lie 23
aval, do See 112| 74| 180\ 133) 143| 32| 37) 47) 63 CN Si7Al (ssl! S15 = BON 740)
Number in 6-inch class
Of EES erate eee 100} 68] 132} 121] 135} 30) 27) 32) 59 Al 25) 60|" es)? e oi
Average length of fish,
6-inch class or larger...| 6.5] 6.9] 6.8| 7.4] 7.3] 6.9] 7.3) 6.9) 6.8] 6.4) 7.0) 6.9| 7.2) 6.8) 6.9
Per cent in 6-inch class
O? [Eig aan as See 89| 92] 73} 91} 94| 94) 73} 68] 94) 44) 76). 92) 51} 94) 67
*Each number designating inches represents the mid-point in a length class; for example, the number 4.0 includes
the bluegills of 3.8—4.2 inches total length.
362
ones over 16 inches were caught in a
fertilized pond, Lauderdale. The bass of
10 inches or longer taken by the test
anglers from fertilized ponds, table 9,
were smaller on an average than those
from the control ponds, table 10; those
from the three fertilized ponds averaged
11.5, 10.5, and 10.8 inches; those from
the three control ponds averaged 11.6,
11.2, and 11.3 inches. The individual
Ittrnors NarurAL History Survey BULLETIN
Vol. 27, Art. 5
bass harvested by test anglers and permit
—*
fishermen from the control ponds had a_
higher average weight than those from the ©
fertilized ponds, table 11.
The number of captures of marked
bass, those with which the ponds had been
stocked in 1946, are indicated in tables 9
and 10. Few marked bass were caught
after the second season of fishing. The —
marked bass grew faster in some ponds —
Table 13.—Numbers of bluegills, in various length classes, caught by Illinois Natural His-
tory Survey test anglers in three unfertilized ponds at Dixon Springs. Bluegills of less than 6
inches in length were returned to the water.
WELLS Boaz ELam
Lencrs Crass, Incnes* (4
1948|1949/1950/1951)1952/1948) 1949|1950|1951/1952)1948 1949/1950)1951|1952
SCHR oo) ag pe eae Ae eee fo] Sy 2 1 Ve EA Pe 1H see foe 1)... 2] ees ee
oF Le fo ae a a ie ras sat 5 1 9) 1 1 i] eared Weasel eee Baa 1 2 1 3
Me Vincedeecty Os ke Miia eae a OPS —4) 5 1 3 1 1 Eales 1)" 23 | se Glee: 4
EC Sea Sa Silo bl. 8i-2 Saat D ae 6| 4 1 3) (22-7) Ole
5 Ue ee... oh Saeed B71 211 | RG) 6|— Se eee 1 9} 9 14 16) 2
LS) 2) aaa ee Lien 23i- VT LA S89 8} 11 3] (12)... 8) S22ierss 1
(SIPS, oc A 5 BalSi) 13) 245 2|- 25) 9). 24) (2) 7) Sage ae 8
Sates tay ty Rh a rc 16ers |\-2 dl 7; 6; 10) 8 28} 6) 13) 9} 14! 51) 49 ©
FXO ip a Sa oh eho cana The TOP AB ATES 6} 4 3) 36) 5) 12) 15) 12)" 16) ome
7 Ae hee aren ee P a ieee nei jaa 53) meee: 4 Rioae of fuer! 143 ier 0A Uae, 1 Berens 1 3 1 2 1a
BOS eS ROME en a Sects fie ae elton et leet tea 5 Sia it ice ace 1 1) eee 1 1) ee
LG eget PR Eee SC epee! Web bawed Pier at Lore 13 | Ia | (el Ime mea Pr eT
Porgl cues. 39) 86| 119} 103) 71| 52) 59| 53) 115) 19| 58) 95| 103) 168) 117
Number in 6-inch class
or lage: cess 28} 37| 48) 64) 55) 16) 42) 21} 93) 14) 33) 31] 52] 101) 103
Average length of fish,
6-inch class or larger...| 6.5] 6.9| 6.6} 6.9) 7.0] 6.8] 6.3) 6.4! 6.6) 6.7| 6.6] 6.8) 6.4] 6.5) 6.7
Per cent in 6-inch class
OPanttere et pc nl<s see 72} 43} 40] 62) 77| 31) 71) 40} 81) 74) -57} 33) SO} 60) 88
*Each number designating inches represents the mid-point in a length class; for example, the number 4.0 includes
the bluegills of 3.8—4.2 inches total length.
Table 14.—Average weights (in pounds) of individual bluegills harvested by hook and line
from each of the Dixon Springs ponds in each of 5 years. Data from which the figures were
derived are in table 20.
Ponpb 1948 1949 1950 1951 1952 AVERAGE
FerTILIzeED
Lauderdale... . 0.21 0.25 0.26 0.32 0.28 0.26 .
Hooker....... 0.24 0.28 0.31 0.27 0.27 0.27
Phelps 0.25 0.28 0.32 0.31 0.31 0.29 |
MOET ACE oie Ve ip ae x OP eal olin beaks ove a oS Coke oe OTe LR Tee eae 0.27 :
4
UNFERTILIZED
Welise. © 1c 455 0.23 0.21 0.21 0.24 0.28 0.24
eget 0.22 0.20 0.20 0.19 0.26 0.21
LLG (7 aa 0.22 Oul7 0.30 0.20 0.20 0.22
PA OVAG Ee ie yie| shal g's ln's wig \ yb aete epege ES Wd Sie Geta eal ee ie ee 0.22
q
August, 1960
than in others. The rate of stocking of the
fertilized ponds, which was three times
that of the control ponds, may have re-
sulted in at least a temporary state of over-
crowding and a consequent retardation in
growth of the bass placed in two of the
fertilized ponds, Phelps and Hooker. Size
distributions of bass caught by test fisher-
men in 1947 and 1948 indicated no over-
crowding in Lauderdale or in any of the
controls.
While the size distributions of bluegills
caught from fertilized and control ponds
were similar, the fertilized ponds yielded
bluegills of larger average size, and
more bluegills of extra large size (8-8%
inches), than the control ponds, tables 12
and 13. The individual bluegills kept by
the test anglers and permit fishermen,
1948-1952, averaged at least one-fourth
pound every year at Phelps and in 4+ out
of 5 years at Lauderdale and Hooker,
table 14. In each of the control ponds,
Wells, Boaz, and Elam, the individual
bluegills averaged one-fourth pound or
heavier in only 1 out of 5 years. For all
years combined, bluegills harvested from
the fertilized ponds averaged 0.27 pound
per fish, those from the controls 0.22
pound.
The three largest bluegill specimens
caught by the test anglers came from the
fertilized ponds; their lengths and weights
were 8.6 inches and 0.51 pound, 8.7 inches
and 0.53 pound, 8.7 inches and 0.55
pound. However, these were not the
largest bluegills caught in the fertilized
ponds. On June 3, 1951, a permit fisher-
man on Phelps Pond caught 12 bluegills
that averaged 0.63 pound per fish.
Annual Hook-and-Line Yields
The recorded hook-and-line yields from
the ponds in this experiment are probably
not the maximum yields of which the
ponds were capable. More fishing might
have been done, and more fish might have
been removed, if the ponds had been open
to year-round fishing, and if there had not
been many other places to fish in the
neighborhood—other farm ponds, Lake
Glendale, and large and small streams.
Some fishermen may have avoided the ex-
perimental ponds because they preferred
fishing where permission to fish and re-
porting of catches were not required. The
HANSEN et al.: HooK-AND-LINE CATCH
363
true hook-and-line yields were somewhat
higher than the recorded yields because
the records did not include the fish taken
by poachers.
Fishing effort in man-hours per acre
and yield in terms of the number and
weight of bass and bluegills harvested per
acre are given in table 15. The actual
recorded numbers and weights of fish re-
moved from the ponds, data from which
per-acre yields were computed, are shown
in table 20. Yields of bluegills from most
ponds increased somewhat between the
early and late years of the experiment.
During 1947, in the first summer of fish-
ing, the yield of bass measuring 10 inches
or larger was much greater from Lauder-
dale Pond than from Hooker or Phelps
or from any of the control ponds, table 15.
This high 1947 yield, 51 fish per acre (47
fish), was not equaled in later years at
Lauderdale or at any of the other ponds
during the period of the study reported
here.
The annual hook-and-line yield of bass
and bluegills combined averaged 48 pounds
per acre from the fertilized ponds and
25 pounds per acre from the control
ponds, table 16. The highest recorded 1-
year yield from a fertilized pond (Lauder-
dale) was 88 pounds per acre, from a
control pond (Boaz) 42 pounds per acre,
table 15. Presumably, higher yields from
the fertilized ponds can be attributed for
the most part to the better bluegill fish-
ing. It should be noticed that the fer-
tilized ponds were fished more intensively
than the controls. In fertilized and con-
trol ponds where total hours of fishing
were about the same for the whole experi-
ment (Lauderdale and Wells, Phelps and
Boaz), the bluegill yields of fertilized
ponds exceeded the bluegill yields of the
controls in both numbers and pounds per
acre, table 16.
For the control ponds in the 5 years in
which both species were caught, the total
bass yield in pounds (actual, not per
acre) almost equaled the total yield of
bluegills, table 17; the bass yield exceeded
the bluegill yield in two of the control
ponds. In the fertilized ponds the total
bluegill yield in pounds was three times
the bass yield.
Published data showing the effect of
pond fertilization on hook-and-line yields
364
are scarce; no such data have been found
for ponds stocked with bass and bluegills
alone. Dugan (1951:415) published an-
nual yields of a number of fertilized ponds
in West Virginia, some of which con-
tained a bass-bluegill combination, but he
did not have yield data from unfertilized
Ittinoris NatrurAL History Survey BULLETIN
Voli’ 27; Artes
bass and bluegills were higher than the
yields in the fertilized ponds at the Dixon
Springs Experiment Station, but the West
Virginia ponds were fished more inten-
sively.
In Alabama, Swingle (1945: 305)
showed a large difference in annual hook-
ponds containing this combination. In and-line yields between a fertilized pond
two of the West Virginia ponds, yields of and an unfertilized pond, each containing
Table 15.—Man-hours of fishing per acre and number and weight of fish per acre removed
by hook and line from each Dixon Springs pond during the years 1947-1952. Catch data from
which figures were derived are in table 20. Years in which fertilizers were applied to pond
watersheds are indicated by S (for spring preceding the fishing season) and F (for fall near the
end of the fishing season). Additional data on watershed fertilization are shown in table 5.
LarGeMouTH Bass BLUEGILLS
Ponp YEAR Hovns age pom
FisHING | Number | Pounds | Number | Pounds | Pep Acre
Per AcrE| Per Acre | Per Acre | Per Acre | Per Acre
FERTILIZED
Lauderdale 1947 42 51 30° 410.3 eee 30
(0.92 acre) 1948 70 15 11 129 27 38
1949 78 25 14 101 25 39
1950F 58 37 25 151 39 64
1951 56 13 11 150 48 59
1952SF 58 36 25 223 63 88
Hooker 1947 71 6 Sot soled ln ae tee bal 3
(1.33 acres) 1948 151 19 14 131 32 46
1949S*F* 216 30 19 127 36 55
1950 162 19 11 133 4] 52
1951F* 108 18 11 217 59 70
1952 120 14 7 72 20 27
Phelps 1947 32 2 | rm eeercmer ee 1
(1.04 acres) 1948F 93 13 6 35 9 15
1949 50 8 + 66 18 22
1950 105 14 8 101 33 41
1951 101 13 10 110 34 44
1952 151 12 9 160 49 58
UNFERTILIZED
Wells 1947 28 15 tt apa ree ier 0 teres 11
(0.97) acre 1948 74 13 12 27 6 18
1949 76 20 12 48 10 22
1950F 52 14 10 58 12 22
1951 50 20 13 70 16 29
1952F 47 25 23 59 16 39
Boaz 1947 24 6 APS here) teal 2 | ad ea 4
(1.01 acres) 1948 134 15 17 62 14 31
1949F* 151 14 8 119 24 32
1950 36 if? 7 30 6 13
| 1951S*8* 57 14 9 88 17 26
| 1952 109 40 33 35 9 42
Elam 1947 16 5 Suita ten Oe 3
(1.55 acres) 1948 35 7 5 24 5 10
1949 45 7 6 43 7 13
1950 76 25 16 26 8 24
| 1951 B2 12 8 74 15 23
1952SF 58 12 9 114 23 32
*Only part of watershed treated with fertilizer in this season.
ey ee
sia tine a iiaemea dal
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BF cape get
—
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Be oat
fe ae
Ls
August, 1960 HANSEN et al.: Hook-anp-LINE CaTcH 365
Table 16.—Average annual number of man-hours of fishing per acre and average annual
hook-and-line yield of largemouth bass and bluegills per acre for the 5-year period 1948-1952
at the six Dixon Springs ponds. Data for individual years are shown in table 15.
Man Hows LARGEMOUTH Bass BLUEGILLS TOTAL
Ponp oF FIsHING PounDs OF
Per Acre Number Pounds Number Pounds Fish Per
Per Acre Per Acre Per Acre Per Acre ACRE
FERTILIZED
Lauderdale... . 64 25 17 151 40 Lyf
Hooker....... 151 20 12 136 38 50
phelps. s5.: 0: 100 1p? 7 94 29 36
TEP TGO SIGSE UE ee oe 19 12 127 36 48
UNFERTILIZED
Wellgo... 0... 60 18 14 52 12 26
BO AZ co es 2 97 19 15 67 14 29
Blames. als 49 13 8 56 12 20
SHEE ES SE | te 17 12 58 HS} 25
Table 17.—Total weight of largemouth bass and bluegills harvested from the Dixon Springs
ponds over the 5 years 1948-1952, the ratio of bass weight to bluegill weight for each pond,
and, for each species, the ratio of weight harvested from fertilized ponds to weight harvested
from controls. Basic data from which figures were derived are in table 20; the 1947 data have
been omitted because in that year bluegills had not reached sizes that most fishermen would
keep.
Five-YEAR YIELD
P Bass: BLUEGILLS
i Largemouth Bass, Bluegills,
Pounds Pounds
FERTILIZED
Wandetdales = fs. 5 es. cn css 79 186 1 : 2.4
iH@OKER. 263 Ae oe ee 83 250 1: 3.0
Palle sarin Ooh. e) = aeons 37 148 W420
BBE sok ke ieee. « | 66 195 LASTI0
UNFERTILIZED
VINCI 265 alee a lea ie a a 69 60 1:0.9
BOHIZS «SA i Le are 74 70 1: 0.9
LEIZyAi) opal ene he a red 69 90 ales
SIREROST Es See Be NE ES Oe 71 7s) ele)
Fertilized 0.9 2.7 Rate nO ae Me ERG om ane
Unfertilized 1h) IE OE cok Seat fe) Pes a oe
six hook-and-line species including bass chemical fertilizer was used than the year
and bluegills. Swingle showed that over
a 5-year period the yield of the fertilized
pond was almost 10 times the yield of the
other pond. The extent to which this
difference in yield may have been due to
_a difference in the total hours of fishing
on the two ponds was not indicated.
A creel census at Broadacres Lake,
North Carolina (King 1943 :209), showed
the annual yield of largemouths, bluegills,
and rough fish was higher the year before
the fertilizer was applied. However, the
decline in yield after fertilization was not
so pronounced in Broadacres Lake as in
nearby Kinney Cameron Lake, which had
not been fertilized.
Catch Rates
Before we consider the catch rates for
fish that were actually harvested from the
Dixon Springs ponds, we shall examine
the catch rates for fish of various sizes
Vol. 27, Art. 5
Ittinoris NaturAL History Survey BULLETIN
366
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caught by the test anglers; these fish
included some too small to keep.
The efforts of fish managers often are
directed toward increasing the numbers of
large fish in a population by reducing the
abundance of small fish, that is, by thin-
ning stunted populations. These efforts
may not be appreciated by a group of
fishermen who are less concerned with the
size of fish than with the number of fish
they catch. This group includes many
children and some adults.
The rates at which the test anglers at
the Dixon Springs ponds caught bass and
bluegills above certain minimum lengths
are shown in tables 18 and 19. The catch
rates for bass less than 10 inches long and
bluegills less than 6 inches long are not
harvest rates, since these fish were re-
turned to the ponds after they were meas-
ured; some of these fish may have been
caught more than once.
The fisherman who prizes any fish, no
matter how small, would have found the
fertilized ponds slightly better than the
control ponds for bass fishing but the con-
trol ponds slightly better than the fer-
tilized ponds for bluegill fishing. The
control ponds proved better than the fer-
tilized ponds for the capture of bluegills
measuring 5 inches or larger. The fisher-
man interested in keeping only the fish
of moderate to large sizes, for example,
bass over 12 inches and bluegills over 7
inches, might have found the control ponds
a little more satisfactory for bass fishing
and the fertilized ponds a little more
satisfactory for bluegill fishing. The bass
fisherman interested in keeping only extra
large fish would have found all of the
ponds disappointing.
Catch Rates for Fish That Were
Harvested.—We turn now to a consider-
ation of catch rates based on fish that
were actually harvested.
The hook-and-line catch rates for fish
harvested from the six ponds at Dixon
Springs are given in table 20. It is evi-
dent from this table that Lauderdale pro-
duced better fishing each year (bass rates
added to bluegill rates) in terms of both
number and pounds per man-hour than
any of the other ponds. It was the only
fertilized pond that consistently produced
better catch rates (bass and bluegill com-
bined) than any of the control ponds.
HANSEN et al.: HooK-AND-LINE CATCH
367
Lauderdale produced better bass _fish-
ing, in terms of number of fish per man-
hour, than any of the controls in 5 out of
6 years and, in terms of pounds per man-
hour, than any of the controls in 3 out of
6 years, figs. 8 and 9. In 4 out of 6 years
the other fertilized ponds produced poorer
bass fishing than any of the control ponds.
However, as mentioned earlier, bass fish-
ing in Phelps Pond may have been poorer
than it should have been in the first year
of fishing as a result of relatively heavy
stocking.
In each year but 1949 Lauderdale led
all other ponds in bluegill fishing, figs. 10
and 11; in that year Phelps led in both
number and pounds of bluegills per man-
hour. In several different years some of
the control ponds had bluegill catch rates
that were equal to or better than the
catch rates in Hooker or Phelps.
The catch rates averaged for six sea-
sons of bass fishing and five of bluegill
fishing are shown for each pond at the
bottom of table 20. Lauderdale ranked
well above any of the other ponds in catch
rates (bass rates added to bluegill rates).
Hooker and Phelps ranked below Wells
and Elam and about on a par with Boaz.
The three fertilized ponds ranked 1,
5, and 6 in terms of both number and
weight of bass kept per hour; 1, 3, and 4+
in terms of number of bluegills kept per
hour; and 1, 2, and 3 in terms of weight
of bluegills kept per hour. In terms of the
weight of bluegills kept per hour, two of
the fertilized ponds, Phelps and Hooker,
outranked the controls by very small
margins. However, the fact that all three
fertilized ponds outranked the three con-
trols is a strong indication that fertiliza-
tion was a benefit to bluegill fishing,
though the benefit may have been small.
At Broadacres Lake, North Carolina,
King (1943:209) found that the catch
rate was a little lower the year fertilizer
was used than the year before. At Crecy
Lake in New Brunswick, Smith (1954:2)
observed a better catch rate of brook trout
after the lake had been fertilized, but
this better catch rate may have been due
in part to other management efforts car-
ried on at the same time, for example,
the addition of young trout.
There is a statistical possibility that
the fertilized ponds, Lauderdale, Hooker,
Vol.27; Axt:S
ILttinors NATURAL History SurRvEY BULLETIN
368
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369
HANSEN et al.: HooK-AND-LINE CaTCH
August, 1960
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370 I_ttinois NAaturAL History Survey BULLETIN
and Phelps, would have ranked better as
bluegill fishing ponds than the controls
even if no fertilizer had been used. H. W.
Norton, statistician in the University of
LARGEMOUTH
0.8
Orr
HOOKER (F)
PHELPS (F)
WELLS
BOAZ
NUMBER PER HOUR
ELAM
1947 1948
LAUDERDALE (F) ——
1949
Vol.:27, Aria
Illinois Animal Science Department, tells
us that where relative productivity of
ponds is unknown the random selection
of the three most productive ponds as the
BASS
1950 1951 1952
Fig. 8—Number of largemouth bass kept per man-hour of angling in fertilized (F) and
unfertilized ponds; data from table 20
August, 1960 HANSEN et al.: HooK-AND-LINE CATCH
0.7 LARGEMOUTH BASS
LAUDERDALE (F)——
0.6 HOOKER (F) —~A——
PHELPS (6): ==
0.5 WELLS ee
BOAZ :
pe ELAM
=!
°
as
xc
WW
a
wn”
a
zs
=)
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a
1947 1948 1949
w
~
aS
1950 1951 1952
Fig. 9—Weight of largemouth bass kept per man-hour of angling in fertilized (F) and
unfertilized ponds; data from table 20.
ones to receive treatment could occur once
in 20 times. Although the ponds were
chosen for fertilization on an arbitrary
rather than on a purely random basis,
we had no advance knowledge of how the
six ponds might rank as fish-producing
waters.
The wide variation in catch rates for
the three fertilized ponds at Dixon Springs
points to the need for studies of catch
rates on ponds before, as well as after,
fertilization. A study of this kind is now
in progress. Wells, Boaz, and Elam, the
three control ponds of the study reported
here, were restocked in 1954 and fertilized
for two seasons. Bluegill catch rates in
each of these ponds were better after fer-
tilization than before.
The fact that bass fishing in both
Hooker and Phelps for the period 1947-
1952 was inferior to bass fishing in each
of the control ponds, table 20, suggests
several possible conclusions: (1) fertili-
zation was of no help to bass fishing,
(2) the benefits of fertilization varied
greatly from pond to pond, or (3) no
positive correlation existed between the
fish population of a pond and the catch
rate. The rotenone census of the fish
populations showed that poor bass fishing
in Hooker and Phelps may not have been
due to scarcity of usable-sized fish in these
ponds so much as to the difficulty of catch-
ing them.
That fishing for both bass and bluegills
was generally much better in Lauderdale
than in the other fertilized ponds is not
easily explained, unless possibly by the
lighter fishing pressure, as discussed in the
section “Fishing Pressures and Catch
Rates.”’ At the time of the 1953 rotenone
census, the number per acre of usable-
sized bass was smaller in Lauderdale than
in Phelps; the number per acre of usable-
372
Ittinoris NaturAL History Survey BULLETIN
Vol. 27, Art. 5
—A—
4.0
BLUEGILL
LAUDERDALE (F)-——
HOOKER (F)
3.0 PHELPS (F) —-—
WELLS —ee
BOAZ
= ELAM
°o
me
xc
WwW
a
c
WwW
@
=
=)
z
1947
1948
1949
1950 1951 1952
Fig. 10.—Number of bluegills kept per man-hour of angling in fertilized (F) and unfer-
tilized ponds; data from table 20.
sized bluegills was smaller in Lauderdale
than in Phelps or Hooker, table 24.
Three factors may have been favorable
to the growth of fish in Lauderdale for
1 or 2 years at the beginning of the study
but not during the last 4 years. (1) Be-
fore the stocking of the ponds for the ex-
periment reported here, fish-food organ-
isms—invertebrates as well as larval am-
phibians—had a longer time to build up
their populations in Lauderdale than in
Hooker or Phelps. In 1946 Lauderdale
was without fish for 6 months prior to
stocking (May to November), Hooker
and Phelps for only 2 months (September
to November). Brown & Ball (1943:
267) showed that certain fish-food organ-
isms as well as fish were destroyed by
the rotenone treatment of Third Sister
Lake, Michigan. Ball & Hayne (1952:
44-5) showed evidence of an expansion
in fish-food organisms in a lake after all
fish had been removed. (2) In November,
1946, Lauderdale was given a slightly
heavier stocking in terms of fish per acre
than the other ponds; this heavier stock-
ing might account for the better bass
fishing in 1947. Presumably the initial
advantage in numbers would have ceased
to be a factor in 1948 or 1949, when the
offspring of the fish used in stocking the
pond reached harvestable size. (3) Lauder-
dale had been dosed with fertilizer in 1945.
As a result of an error in the reported
area of the pond, Lauderdale received
more fertilizer in terms of pounds per
acre at full stage than either Hooker or
Phelps. However, water levels in mid-
summer were always much lower in
Phelps than in Lauderdale, so that Phelps
Le ee re
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August, 1960
was probably dosed at least as heavily as
Lauderdale after about the middle of
July each year.
We have shown in table 8 that Lauder-
dale was often clearer than Hooker and
Phelps, a condition that might have as-
sisted fish both in finding food and in
locating baits. On the other hand, it is
ro BLUEGILL
0.9
HOOKER (F) —A—
PHERPS (ey ——
0.8
WELLS “
BOAZ —-
0.7 ELAM —x—
PER HOUR
POUNDS
1947
1948 1949
HANSEN et al.: HooK-ANp-LINE CaTCH
LAUDERDALE (F) ——
373
possible that the clearer water increased
the chances that the fish might be fright-
ened by fishermen.
Trends in Catch Rates.—Certain
trends in the yearly catch rates were ob-
served for both fertilized and unfertilized
ponds at Dixon Springs, but trends dif-
fered from one pond to another. In some
1950 195 1952
Fig. 11—Weight of bluegills kept per man-hour of angling in fertilized (F) and unfer-
tilized ponds; data from table 20.
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374
August, 1960
ponds, bass catch rates changed only
slightly during the experiment; in others,
catch rates were high at the beginning,
dropped off for 1 or 2 years, and then
improved toward the end of the experi-
ment. The notion of many fishermen in
Pope and Johnson counties that bass fish-
ing in small ponds is best the first year
they are fished was borne out in the fish-
ing results only at Lauderdale and Wells,
figs. 8 and 9.
The observed depression in bass catch
rates seen in some of the ponds in the
second or third year after being stocked
probably was due to a reduction in the
numbers of the original stock of bass as a
result of angling and natural mortality,
combined with a delay in population re-
placement through reproduction.
In all of the ponds except Phelps and
Lauderdale, figs. 10 and 11, bluegill catch
rates were highest during the fourth year
of bluegill fishing (the fifth year after
stocking). Phelps Pond furnished its best
bluegill fishing in the second year and
Lauderdale in the fifth year of bluegill
fishing. “The most common trend in
bluegill catch rates—one that was ex-
hibited by four of the six ponds—was a
general improvement in rates over the
first 4 years of bluegill fishing, 1948-1951.
Three of these four ponds showed con-
spicuous declines in catch rates in the fifth
year, 1952.
Fishing Pressures and Catch
Rates.—Bennett & Weiss (1959) re-
cently showed that ponds in I]linois sub-
jected to comparatively light fishing pres-
sures—Ridge Lake, Big Pond, and the
ponds in the present experiment—pro-
vided better catch rates than ponds in the
Busch Wildlife Area, Missouri, that were
subjected to extremely heavy fishing pres-
sures.
Although we were unable to discover
a clearcut relationship between _ fishing
pressures and catch rates in the Dixon
Springs ponds, we found that the two
ponds with the smallest total number of
man-hours of fishing, Lauderdale (fer-
tilized) and Wells (unfertilized), had the
highest catch rates of bass of desirable
sizes, table 20.
We have tried in the following discus-
sion to eliminate fishing pressure as a
possible factor in catch rate calculations
HANSEN et al.: Hook-AND-LINE CATCH
373
by comparing only those ponds that were
fished at approximately equal rates, table
2
Under equal or nearly equal fishing
pressures, bass fishing was in some in-
stances better in the fertilized ponds, in
other instances better in the controls, but
bluegill fishing was consistently better in
the fertilized ponds.
The catch rates shown for Lauderdale
(fertilized) and Wells (control) are of
special interest because fishing in these
two ponds was done almost entirely by
the Natural History Survey test anglers,
assuring that not only the number of
hours but fishing skills and fishing meth-
ods were nearly the same in a given year.
In the + years that Lauderdale and
Wells are represented in table 21, bluegill
fishing in terms of number of fish caught
per hour was 1.9 to 5.2 times as good in
Lauderdale as in Wells—in terms of
pounds caught per hour, 2.3 to 4.9 times
as good in Lauderdale as in Wells. In the
same 4 years, bass fishing was notably bet-
ter in Lauderdale than in Wells in 1 year,
better in Wells than in Lauderdale in
1 year.
Over the entire period of study, total
hours of fishing were nearly equal for
Lauderdale (fertilized) and Wells (un-
fertilized), each fished about 300 hours,
and for Phelps (fertilized) and Boaz
(unfertilized), each fished in the neigh-
borhood of 500 hours, table 20 (bottom).
The catch rates for bass, in 6 years of
fishing, were better in Lauderdale than in
Wells but better in Boaz than in Phelps.
The catch rates for bluegills, in 5 years
of fishing, were considerably better in
Lauderdale than in Wells and somewhat
better in Phelps than in Boaz.
Fertilization Rates and Catch
Rates.—As described in the section “Fer-
tilizing the Ponds,” the N-P-K formulas
used in the period 1947-1949 were dif-
ferent from the ones used in later years,
table 7. As a consequence of changes in
the fertilizer formula and in the number
of treatments, the ponds received about
2.0 times as much nitrogen, 1.3 times as
much phosphorus (P,O,), and about 3.2
times as much potassium (K,O) in 1951
and in later years as they had received
each year in the period 1947-1949. Al-
though the number of fertilizer applica-
376 Ittrnois NATURAL
Hisrory Survey BULLETIN
Vol. 27 ArteS
Table 22.—Catch rates (number and weight of fish per man-hour of fishing) of largemouth
bass and bluegills from Dixon Springs ponds in two periods, one of comparatively light (1947-
1949) and one of comparatively heavy (1951, 1952) fertilization.
Details of pond fertilizaticn
program are shown in table 7. Figures were derived from data in table 20.
LARGEMOUTH Bass BLvuEGILLs*
: FERTILIZATION - am LES [ES
PEROR ON ES aENe Number Pounds Number Pounds
Per Hour Per Hour Per Hour Per Hour
Licut (1947-1949)
Fettiiized ponds isi 85 asa ss fe 0.27 0.16 1.05 0.26
Unfertilized ponds..............| 0.23 OrTy 0.65 0.13
Diff erencéc chtetoe -ctacter Bates | +0.04 —0.01 +0.40 +0.13
Heavy (1951, 1952) |
Fertilized ponds ee ee tia 0.23 0.16 1.88 0.55
Unfertilized ponds.............. 0.35 0.27 1.46 0.32
DOS EVENCE = ise WAeh ea oe eae —0.12 —0.11 +0.42 +0.23
*Bluegill fishing in 1948, 1949, 1951, and 1952 but not in 1947.
tions given annually in 1951-1953 was
double the number given in 1947-1949,
the amount of phosphorus (the compo-
nent generally considered to be most im-
portant in pond fertilization) was in-
creased only about one-third.
Catch rates may be compared for the
years under the lighter treatment (1947-—
1949 for bass, 1948 and 1949 for bluegills)
with the years under the heavier rates
(1951 and 1952), table 22. Bass fishing,
as judged by differences in catch rates be-
tween fertilized and unfertilized ponds,
was relatively better under the lighter
treatment; bluegill fishing—especially in
pounds caught per hour—was better un-
der the heavier treatment. Since bluegill
catch rates improved in the control ponds
as well as in the fertilized ponds during
the period of the heavier treatments, blue-
gill fishing might have improved in the
fertilized ponds even if the rate of fertili-
zation had not been increased.
POND FERTILIZATION AND
STANDING CROPS
When the standing crops of the Dixon
Springs ponds were determined by ro-
tenone censuses in September, 1953, the
ponds had been closed to all fishing for
the 12-month period preceding the census.
Fertilization of Lauderdale, Hooker, and
Phelps had been continued during the
summer of 1953 in approximately the same
manner as in 1951 and 1952, table 7. For
each pond the standing crop in pounds per
acre was computed from the reduced area
of the pond at the time of the census,
rather than from the area at full stage.
Both full stage and reduced areas are
shown in table 1.
Studies by Brown & Ball (1943), Ball
(1948), Carlander & Lewis (1948), and
Krumholz (1950a) demonstrated that in
some situations considerable percentages
of the populations of fish killed by rote-
none are not recovered in the census op-
erations. A possible hindrance to the re-
covery of fish in the control ponds at
Dixon Springs was a dense growth of
Chara in which dying and dead fish might —
have become entangled. The possibility
that the Chara interfered with the re-
covery of fish was not investigated by un-
derwater examination. We know of no
reason other than the possible effect of
Chara to believe that the percentage of
fish recovered was different in fertilized —
than in unfertilized ponds.
Bass collected from the ponds after the
rotenone treatment were grouped into two
length categories—those 10.0 inches (total
length) or larger and those smaller than
10.0 inches. The bluegills collected from
the first four ponds examined (Lauder-
dale, Phelps, Wells, and Boaz) were
divided into four length categories as fol- —
lows:
inches or larger.
various length categories, for the most
1.0-1.9, 2.0-3.4, 3.5-5.9, and 6.0m
Natural size groupings —
permitted the rapid sorting of fish into the ~
Asciaeg
August, 1960 HANSEN et al.:
part without actual measurement. Blue-
gills collected from the other two ponds
(Hooker and Elam) were grouped into
two categories: under 6.0 inches and 6.0
inches or larger.
The populations of the first four ponds
varied considerably with respect to abund-
ance of bluegills in the four length cate-
gories, table 23. The variations appear to
have been unrelated to the fertilization
program. Lauderdale Pond was char-
acterized by an absence of bluegills 1.0-
1.9 inches long, by an spinidance of bine:
gills 2.0-3.4 inches long, and a relative
scarcity of bluegills 3.5—-5.9 inches long
and 6.0 inches or larger. ‘This pond, in
which bluegill fishing had been better
than in any other, was more remarkable
for the weight of 2.0—3.4-inch bluegills
(95 pounds per acre) than for the weight
of bluegills measuring 6.0 or larger.
Two population characteristics were
seen in these four ponds, table 23. (1)
While the ponds appeared to be quite
densely populated with bluegills under
3.5 inches, they showed no evidence of
overpopulation with bluegills of 3.5 inches
or longer. (2) In number of bluegills per
acre in each of the four ponds, great dif-
ferences existed between the two smaller
length categories and only minor differ-
ences between the two greater length cate-
gories.
Of the fish that, according to tables
12 and 13, were likely to be caught by
anglers (those 3.5 inches or larger), the
ones measuring 3.5—5.9 inches were about
as numerous as those of greater lengths.
HooKk-ANb-LINE CATCH
377
The number and weight of bass and
bluegills (in two length categories for
each species ) recovered from Ue of the
six ponds in the rotenone census are shown
in table 24. Just as there was overlap in
the catch rates for fertilized and unferti-
lized ponds, there was also overlap in the
standing crops. Bass 10 inches or larger,
bluegills 6 inches or larger, and bluegills
smaller than 6 inches were a little more
abundant in the fertilized ponds, while
bass smaller than 10 inches were more
abundant in the control ponds, table 24.
Rass of all lengths were more abundant
in the control ponds, while bluegills of
all lengths were more abundant in the
fertilized ponds. The weight per acre of
bass of all lengths was nearly the same in
fertilized as in control ponds; the weight
per acre of bluegills of all lengths was
higher in the fertilized ponds.
The three fertilized ponds averaged 292
pounds of fish per acre (bass and bluegills
of all lengths) ; the controls averaged 238
pounds per acre (ratio 1.2:1).
In Alabama ponds treated nine times a
season with 6-8-4 fertilizer at the rate of
100 pounds per acre per treatment and
NaNO, at the rate of 10 pounds per
acre per treatment—roughly equivalent to
the annual treatments applied at Dixon
Springs in the period 1951-1953—Swingle
(1947:24) found that the average stand-
ing crop (weight per acre) of bass and
bluegills of all sizes in three fertilized
ponds was about double the standing crop
in the control pond (ratio 2.0:1). In this
Alabama observation, an overlap was
Table 23.—Standing crops, in terms of number and weight (per acre), of bluegills recov-
ered in the rotenone censuses of four of the six Dixon Springs ponds, September 8-17, 1953;
the fish were separated into four length categories.
The data from Hooker and Elam ponds
are not included in this table because the bluegills from those ponds were separated into only
two length groups, under 6 inches and 6 inches and longer.
FERTILIZED Ponps UNFERTILIZED PonpDs
Tora LENGTH, Lauderdale Phelps Wells Boaz
INCHES
Number | Pounds | Number | Pounds | Number | Pounds | Number |} Pounds
Per Acre | Per Acre | Per Acre | Per Acre | Per Acre | Per Acre | Per Acre | Per Acre
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August, 1960
found between fertilized and control ponds
in standing crops of bass but not of blue-
gills.
In another experiment in which Ala-
bama ponds were treated 12 times a sea-
son with 6.6-8-2, each time at the rate of
120 pounds per acre, Swingle (1947: 22)
found that the average of the standing
crops of bass and bluegills of all sizes in
three fertilized ponds was nearly three
times the standing crop in the control
pond (ratio 2.9:1).
That Alabama ponds showed a better
response to fertilization than the Dixon
Springs ponds under similar treatment
is possibly explained by differences in
natural fertility of the Alabama and Illi-
nois ponds in question. It might be easier
through direct fertilization to double or
triple a low standing crop of fish in an
area of low soil fertility than in one of
somewhat higher soil fertility. The un-
treated Alabama ponds, 6 to 12 months
after being stocked, contained 100 to 125
pounds of bass and bluegills per acre
(Swingle 1947: 22, 24), whereas the three
untreated ponds at Dixon Springs, 6 years
after being stocked, contained 169 to 308
pounds of bass and bluegills per acre, table
24. It is possible that in the 6- to 12-
month periods between the stocking and
draining of the Alabama ponds the stand-
ing crops had not had time to reach maxi-
mum levels. Krumholz (1948: 405, 409)
found that ponds stocked in May or June
with bluegills alone or with bluegills,
largemouth bass, and other species con-
tained much larger standing crops the
second October than the first October
after being stocked.
Ball & Tait (1952:6, 17) used some-
what less fertilizer in southern Michigan
ponds than was used at Dixon Springs in
1951-1953 and obtained a slightly better
response from the treatments. ‘Three
Michigan ponds were treated five times a
season with 10-6-4 fertilizer at the rate
of 100 pounds per acre each time. The
fertilized ponds had standing crops of
bass and bluegills that averaged 365
pounds per acre, and three similar, un-
fertilized ponds had standing crops that
averaged 261 pounds per acre (ratio
1.4:1). There was a very wide range
in the standing crops of the fertilized
ponds, 165 to 721 pounds per acre; the
HANSEN et al.: HooK-ANp-LINE CatcH
379
standing crops of the unfertilized ponds
ranged from 209 to 379 pounds per acre.
In West Virginia, Surber (1948d)
studied the effect of various rates of ap-
plication of 10-5-5 fertilizer on the blue-
gill production in hatchery ponds. Three
groups of ponds were treated five to seven
times a growing season at rates of 100,
200, or 300 pounds of 10-5-5 fertilizer per
treatment. Combining the data of Surber
(19484:201-2) for summer and _ fall
hatchery crops (but omitting the data
from a pond in which there was abnor-
mally high mortality) we find that crop
weights were 1.9, 2.3, and 2.3 times as
large in the three groups of fertilized
ponds as in the control ponds.
STANDING CROPS AND
FISHING SUCCESS
For many years aquatic biologists have
been interested in the standing crops of
lakes and ponds as a basis for predicting
hook-and-line yields. Thompson (1941:
213) thought that central Illinois lakes
stocked with bass, bluegills, and crappies
could give sustained annual hook-and-line
yields that would amount to half their
carrying capacities. He thought that the
corresponding yields for southern Illinois
lakes might be close to three-fourths of
their carrying capacities. By carrying
capacity, “Thompson meant the _ total
amount of fish in a lake at saturation
point, or the maximum standing crop.
Krumholz (19504: 29) estimated that In-
diana ponds were capable of giving sus-
tained annual yields of “as much as half
and perhaps more”’ of their standing crops.
Neither Thompson nor Krumbholz spec-
ulated on the amount of fishing time that
might be required to bring about such
yields.
We may now compare the hook-and-
line yields of the Dixon Springs ponds
during the last 3 years of fishing with the
standing crops as observed in the 1953
censuses, table 25. ‘The hook-and-line
vields were for the most part made up of
bass more than 10 inches and _ bluegills
more than 6 inches total length; the stand-
ing crops included all fish, irrespective
of size.
For each Dixon Springs pond, the 1952
yield alone, as well as the average yield
380
for the years 1950, 1951, and 1952,
amounted to a much smaller percentage of
the standing crop, as observed in Septem-
ber, 1953, table 25, than the sustained
yield estimates of Thompson and Krum-
holz. Percentages were higher in the fer-
tilized than in the control ponds. ‘The
most heavily fished ponds in 1952 were
Hooker, Phelps, and Boaz. The 1952 fish
yields in these three ponds were respec-
tively 11, 19, and 14 per cent of their
observed standing crops. The largest yield
in relation to standing crop (28 per cent)
was recorded from Lauderdale Pond,
where fishing in 1952 was lighter, rather
than heavier, than in Hooker, Phelps, or
Boaz. If, as is possible, fewer fish were
recovered in the rotenone censuses than
were actually present, the true percentage
values would be even lower than those
shown. On the other hand, if unreported
yields of fish taken by poachers could be
determined and included in the calcula-
tions, the percentages for at least some of
the ponds might be higher than those
shown.
Figures representing the 1952 bass har-
vest and the numbers and weights of
harvestable bass in the ponds at the time
of the 1953 census are shown in table 26.
Similar figures for bluegills are shown in
table 27. If the 1953 fish census gave a
close approximation of the population of
harvestable fish in 1952, the efficiency of
Ittinors NAtuRAL History Survey BULLETIN
Vol. 27, Art.’5
the 1952 fish harvest (the fish caught in
relation to the fish present) appears to
have been greater for bass in the control
ponds and for bluegills in the fertilized
ponds.
The relations between catch per hour
and the abundance of fish of desirable
sizes are shown for bass in table 28 and
for bluegills in table 29. Data in these
tables, especially the ratios expressed, seem
to indicate that in the fertilized ponds
bass fishing was poorer than would be _
expected from the numbers of 10-inch or
larger bass present and that bluegill fish-
ing was better than would be expected
from the populations of 6-inch or larger
bluegills.
Swingle (1945:305) observed that the
catch in fertilized ponds was usually
greater than would be expected from the
increases in their fish-carrying capacities,
but he did not say whether his observa-
tion applied to both bass and bluegills.
He attributed the phenomenon to the
blooms of microscopic algae, which he be-
lieved helped to conceal the anglers from
the fish they were trying to catch. Results
of the Dixon Springs experiment indicate
that if plankton algae helped to conceal
the fishermen from the bass it may also
have helped to conceal baits from these
fish.
We have ordinarily assumed that the
pond containing the largest population of
Table 25.—Standing crop of largemouth bass and bluegills (fish of all sizes) in the 1953
rotenone census of the six Dixon Springs ponds, and the hook-and-line yield of largemouth bass
and bluegills during the last years of the experiment, 1950-1952. Yield data are from table 15,
standing crop data from table 24.
ANNUAL HooK-AND-LINE
YIELD AS A PERCENTAGE OF
STANDING Y1eELD, PounpDs PER ACRE STANDING Crop
Ponxp Crop, Pounps
ee 1950-1952 ae 1950-1952
1952 Average Average
FERTILIZED
Lauderdale...... 318 88 70 28 22
IOOK eRe c eicke sesie 255 27 50 11 20
Phelpsi eu: toys 302 58 48 19 16
RUPEE O Sve slates [ois fod aes aa shat hsce mca ORE eee ere 20* 19*
UNFERTILIZED
Wells Ay. fia helen 238i, 39 30 16 13
| bay ease ear en pibee oe 308 42 27 14 9
Blame wdc 169 32 26 19 1
RAPEI IED Cla ate a tikes. iipbe 83° aura) tsi] Ge SecA O peaee Seoece el ee 16* Lee
*Average of three percentages directly above.
August, 1960 HANSEN et al.: HooK-AND-LINE CATCH 381
fish of desirable sizes is the one likely to prisingly little correlation was found be-
provide the best fishing. However, sur- tween numbers of bass and bluegills of
Table 26.—The 1952 hook-and-line yield of largemouth bass (number and pounds per
acre) as a percentage of the 1953 rotenone census figure in each of the Dixon Springs ponds;
also the ratio of fertilized to unfertilized ponds in number and pounds of bass per acre. Basic
data are from tables 15 and 24.
LarGEMOUTH Bass 1952 YIELD As A PERCENT-
10-INCHES OR LaRGER, eerie: ae YIELD, AGE OF 1953 CENsuUS
1953 RoreENOoNE CENSUS SAG SEASON Ficure
Ponp ;
Number Pounds Number Pounds Number Pounds
Per Acre Per Acre Per Acre Per Acre Per Acre Per Acre
FERTILIZED
Lauderdale.... 58 70 36 25 62 36
Hooker....... 49 43 14 7 29 16
helps... ...:. 64 67 12 9 19 13)
Average....... i 60 21 14 37 f 22T
UNFERTILIZED
WVElIS. «5.16 ws: 55 45 25 23 45 51
| EXO 6 eee en ei 59 62 40 33 68 53
Blame. <6: - 24 21 12 9 50 43
Average....... 46 43 26 22 544 497
Fertilized 1.24 1.40 0.81 OSG4 cag Ween a eee |e ee Oe
Unfertilized 1.00 1.00 1.00 Te OOP gl eee aac eter hs a S| ee ge ee
*The hook-and-line yields of bass from Lauderdale and Wells were made up of fish measuring at least 10.0 inches
total length. No measurements of bass caught by permit fishermen were recorded, but these fishermen were supposed not
to keep bass less than 10.0 inches in length.
+Average of three percentages directly above.
Table 27—The 1952 hook-and-line yield of bluezills (number and pounds per acre) as a
percentage of the 1953 rotenone census figure for each of the Dixon Springs ponds; also the
ratio of fertilized to unfertilized ponds in number and pounds of bluegills per acre. Basic data
are from tables 15 and 24.
BLuecILits 6 INCHES oR BLueGILLt YIELD, 1952 Yre_p as A PERCENT-
Larcer, 1953 1952 FisHInG AGE OF 1953 CENSUS
RoTeENONE CENSUS Season* FIGURE
Ponp ; ie
Number Pounds Number Pounds Number Pounds
Per Acre Per Acre Per Acre Per Acre Per Acre Per Acre
FERTILIZED
Lauderdale... . 463 129 223 63 48 49
Hooker. ...... 629 147 72. 20 11 14
Phelps........ 706 146 160 49 23 34
AGS Ne 599 141 151 44 277 Bei
UNFERTILIZED
\El ee 463 108 59 16 13 15
Deh. 624 1333) 35 9 6 7
knee 442 81 114 23 26 28
WAUETAGE...:..« 510 107 69 16 15+ 177
Fertilized 1S USK 131 2.19 DreT Sih. KORE ee PER Cie all Meat ae WE eae
Unfertilized 1.00 1.00 1.00 LOO.) eee er eee eee
*The hook-and-line yields of bluegills from Lauderdale and Wells were made up of bluegills measuring at leact
6.0 inches total length. The sizes of fish taken from the other ponds were not governed by restrictions on fishermen.
jAverage of three percentages directly above.
382 Intinors Natura History Survey BULLETIN Vol. 27, Art. 5
desirable sizes in the several ponds in the cess in the same ponds in the preceding
1953 census and the record of fishing suc- years, tables 26-29. Lauderdale, the pond
Table 28.—Number and pounds (per acre) of largemouth bass of at least 10.0 inches total
length in the 1953 rotenone census, the hook-and-line catch rate for 1952, and the average annual
hook-and-line catch rate for 1950-1952 in each of the Dixon Springs ponds; also the ratio of
fertilized to unfertilized ponds in number and pounds of bass per acre and per hour. Basic
data are from tables 20 and 24.
LarRGEMOUTH Bass, CaTcH PER
LARGEMOUTH Bass Man-Hour*
\LOIncHes or Larcer, 1953
RoTrenone CENSUS
Ponp . 1952 1950-1952 AVERAGE
Number Pounds Number Pounds Number Pounds
Per Acre Per Acre Per Hour Per Hour Per Hour Per Hour
FERTILIZED
Lauderdale.... 58 70 0.62 0.43 0.50 0.35
Hooker....... 49 43 0.12 0.06 0.14 0.08
Phelps. 64 67 0.08 0.06 One 0.08
Average 57 60 0.27 0.18 0.25 0.17
UNFERTILIZED
Wrellste ses 55 45 0.52 0.48 0.39 0.32
BORZ eee 59 62 0.36 0.30 0.31 0.22
Blames. bee: 24 21 0.21 0.16 0.30 0.21
LLDET OEE snehe ss 46 43 0.36 0.31 0.33 0.25
Fertilized 1.24 1.40 0.75 0.58 0.76 0.68
Unfertilized 1.00 1.00 1.00 1.00 1.00 1.00
*Information on the sizes of bass in the catch is in the first footnote to table 26.
Table 29——Number and pounds (per acre) of bluegills of at least 6.0 inches total length
in the 1953 rotenone census, the hook-and-line catch rate for 1952, and the average annual
hook-and-line catch rate for 1950-1952 in each of the Dixon Springs ponds; also the ratio of
fertilized to unfertilized ponds in number and pounds of bluegills per acre and per hour. Basic
data are from tables 20 and 24.
BLuEGILts, CaTcH
BLvueEcILts 6 INcHES Per Man-Hovur*
or Larcer, 1953
RotTeNONE CENSUS
Ponp 1952 1950-1952 AVERAGE
Number Pounds Number Pounds Number Pounds
Per Acre Per Acre Per Hour Per Hour Per Hour Per Hour
FERTILIZED
Lauderdale.... 463 129 3.87 1.09 3.05 0.88
Hooker....... 629 147 0.60 0.16 1.15 0.32
Phelps: > i565 % 706 146 1.06 0.32 1.03 0.32
Average....... 599 141 1.84 0.52 1.74 0.51
UNFERTILIZED
Wellsiz os 3-: 463 108 1.24 0.35 1h 245) 0.31
Boazastenee 624 133 0.32 0.08 0.89 0.18
Blamcca sce 442 81 1.97 0.40 1.55 0.32
Average....... 510 107 1.18 0.28 1223 0.27
Fertilized 7; 15332 1.56 1.86 1.41 1.85
Unfertilized..... 1.00 1.00 1.00 1.00 1.00 1.00
*Information on sizes of bluegills in the catch is in the first footnote to table 27.
August, 1960
that had generally furnished the highest
yields and catch rates did not at the time
of the census contain the largest popula-
tion of fish of desirable sizes, while Phelps,
which had consistently furnished poorer
fishing than Lauderdale, contained a rela-
tively large population of bass and _ blue-
gills of desirable sizes, tables 28 and 29.
Assuming that our data were adequate
for the comparison just made, we may
conclude that our failure to find a closer
relationship between standing crops and
fishing success was due to one or both
of the following reasons: (1) the stand-
ing crops were not the same in all years
of the experiment; (2) catch rates were
greatly affected by some factor other than
the size of the standing crops.
FIELD FERTILIZATION
AND FISHING SUCCESS
The application of chemical fertilizers
to fields draining into ponds is sometimes
thought to be a benefit to fish production
and fishing in such bodies of water. This
line of thinking is consistent with the
widely accepted idea that fertility of the
land comprising the watershed of a lake
or river has a profound effect on fish
production. Little has been said in the
literature of pond fertilization, however,
concerning the extent of the benefits to
pond fishing that may be derived from
watershed treatment.
The quantity of fertilizer that might
reach a pond in runoff from its watershed
would vary from one pond to another and
would be difficult to estimate. It would
depend, for example, on the size of water-
shed, the kind and amount of fertilizer
used, and the extent to which it was mixed
with the soil as it was applied. It would
also depend on the time lapse between
fertilizer applications and occurrence of
rainstorms, the severity of the storms, the
tendency of the soil to erode, and the den-
sity of protective vegetation. Part of the
fertilizer washed from fields into ponds
would later be lost over the pond spill-
Way.
Phosphorus applied ‘to fields as rock
phosphate is slowly soluble and, theoret-
ically, would be of less benefit to a pond
than phosphorus applied as_ superphos-
phate, which is readily soluble. However,
HANSEN et al.: HooK-ANpD-LINE CATCH
383
phosphorus applied to fields in the form
of superphosphate combines rapidly, in the
presence of moisture, with elements in the
soil to form slowly soluble calcium phos-
phate and relatively insoluble compounds
with iron and aluminum. Except for the
superphosphate that might be washed
from a field into a pond very soon after a
soil treatment, the phosphorus carried into
a pond from its watershed would be in a
relatively insoluble state. Nitrogen and
potassium would be present in runoff for
a comparatively short time, probably less
than a year. Nitrogen is taken up quickly
by plants or is lost into the air, while
potassium salts tend to leach downward
into the soil, where they cannot be re-
moved by water running over the soil
surface.
In the period 1935-1937, previous to
the beginning of the study reported here,
fields surrounding each of the Dixon
Springs ponds were given an application
of crushed limestone, and fields surround-
ing three of the six ponds (Lauderdale,
Wells, and Elam) were treated with
superphosphate, table 5.
In the course of the study, the water-
shed of each pond was again treated with
crushed limestone; for the first time each
watershed was treated with rock phos-
phate and each watershed except that of
Phelps was treated one or more times
with chemical fertilizers supplying nitro-
gen, phosphorus, and potassium, separately
or all three in combination, table 5. Barn-
yard manure was applied to one of the
fields.
Actual demonstrations of the effect, on
fishing success, of crushed limestone ap-
plied to ponds or pond watersheds in the
United States seem to be lacking. In
Europe, Schaeperclaus (1933:162) re-
ported that applying lime to pond bottoms
protects the health of fish and produces
favorable “biological conditions, which
react to increase the yield.’’ Because the
watersheds of all Dixon Springs ponds
received approximately equal applications
of limestone, no conclusions can be drawn
as to what effect, if any, liming of the
watersheds had on fishing success in these
ponds.
Although phosphorus is generally be-
lieved to be important as a pond fertilizer,
its value to fishing when applied to pond
384
watersheds is difficult or impossible to de-
termine from data gathered in the Dixon
Springs experiment.
The water of Boaz, the only control
pond that had no record of superphos-
phate, rock phosphate, or complete fer-
tilizer application to its watershed until
1949, had a higher phosphate content in
1947 than the water of any of the other
five ponds at Dixon Springs, table 3.
It is interesting to compare catch rates
I_ttino1is NATURAL History Survey BULLETIN
Vol. 27, Ar am
in Boaz with catch rates in the other con- —
trol ponds before rock phosphate was ap-
plied to part of the Boaz watershed in the —
fall of 1949. Superphosphate had been ~
applied to the Elam watershed in 1936
and to the Wells watershed in 1937. In
the years 1947-1949, bass fishing was not _
so good in Boaz as in Wells or Elam. In —
1948 and 1949, bluegill fishing was slight- — {
ly better in Boaz than in Wells but not —
quite so good as in Elam, table 30. .
Table 30.—Catch rates (number and pounds of fish removed per hour of fishing) at Dixon .
Springs ponds, 1947-1952. Years in which fertilizers were applied to pond watersheds are indi-
cated by S (for spring preceding the fishing season) and F (for fall near the end of the fishing —
season). Data are from table 20. Additional data on watershed fertilization are in table 5.
LarRGEMOUTH Bass BLUEGILLS
aie —— Number Pounds Number Pounds 3
Per Hour Per Hour Per Hour Per Hour ©
FERTILIZED
anderdales . 2.0 eee wee 1947 1521 0.72° |e... SS
1948 0.22 0.16 1.86 0.39
1949 0.32 0.18 1.29 0.32
1950F 0.64 0.43 2.62 0.68
1951 0.23 0.19 2.65 0.85
1952SF 0.62 0.43 3.87 1.09
TIOGR ER ta oe ee be ee 1947 0.08 0.05 |....... 223 aS
1948 0.12 0.09 0.87 0.21
1949S*F* 0.14 0.09 0.59 0.17
1950 0.12 0.07 0.82 0.26
1951F* 0.17 0.10 2.02 0.55
1952 0.12 0.06 0.60 0.16
PH eMDSe) to rene a senha ee a 1947 0.06 0.03}... one. spare « alle
1948F 0.14 0.06 0.37 0.09
1949 0.15 0.08 1.33 0.36
1950 0.14 0.07 0.96 0.31
1951 0.13 0.10 1.08 0.33
1952 0.08 0.06 -1.06 0.32
UNFERTILIZED
Wellsaiin or Fed eo hae: 1947 0.56 0.41 weeecesveaeelecir. naa
1948 0.18 0217 0.36 0.08
1949 0.26 0.16 0.64 0.14
1950F 0.28 0.20 trat2 0.24
1951 0.39 0.26 1.39 0.33
1952F 0.52 0.48 1.24 0.35
SOA Er eth ees he eee 1947 0.25 0.17 Se ee eS
1948 0.11 0.13 0.47 0.10
1949F* 0.09 0.05 0.78 0.16
1950 0.33 0.19 0.83 0.17
1951S*F* 0.24 0.16 1.53 0.29
1952 0.36 0.30 0.32 0.08
Big ee aces eee cee tes 1947 0.32 0.20 Ls
1948 0.20 0.13 0.68 0.15
1949 0.16 0.14 0.94 0.16
1950 0.33 0.21 0.34 0.10
1951 0.37 0.26 2235 0.47
1952SF 0.21 0.16 1.97 0.40
*Only part of watershed treated with fertilizer
in this season.
August, 1960
Bass catch rates improved in Wells
Pond in 1951, following fertilizer treat-
ment of its watershed in the fall of 1950,
and in Boaz Pond in 1950 and 1952, fol-
lowing treatment of half of its watershed
in 1949 and the other half in 1951, table
30. A drop in the bass catch rate oc-
curred in Elam Pond in 1952, after treat-
ment of its watershed in the spring of that
year.
Bluegill catch rates rose slightly in
Boaz in 1950, following treatment of half
of its watershed in the fall of 1949, and
in Wells Pond in 1951, following treat-
ment of its watershed the previous fall.
The bluegill catch rates improved in Boaz
in 1951, following treatment of part of
the watershed in the spring of that year,
but they declined in 1952, after treatment
of another part of the watershed in the
autumn of 1951. They declined in Elam
in 1952, following application of fertilizer
to its watershed in the spring of that year.
That the field treatments may not have
been the cause of improved bluegill catch
rates in Wells is indicated by the trend in
catch rates leading up to the field treat-
ment of 1950; bluegill catch rates were
showing year-to-year improvement before
this treatment.
Examination of the catch rates for the
directly fertilized ponds, Lauderdale,
Hooker, and Phelps, in the fishing seasons
following both direct and indirect fer-
tilization shows that in some cases bluegill
fishing was better in the season after a
field treatment than before, table 30.
However, in most of the cases the im-
proved fishing could have been caused by
the increased rates of pond fertilization,
which were begun in the spring of 1950,
rather than by the field fertilization.
While the evidence that field fertiliza-
tion may have helped fishing in the Dixon
Springs ponds is inconclusive, we should
perhaps state our conclusion on pond fer-
tilization as follows: that, in addition to
any improvement in fishing success that
might have resulted from watershed treat-
ments, there is evidence of improvement in
bluegill fishing from direct fertilization
-of the ponds. The pond owner who
strives for better bluegill fishing should
therefore not depend upon field fertiliza-
tion, but should apply fertilizer directly
to the pond.
HANSEN et al.: Hook-ANp-LINE CatTcH
385
ECONOMICS OF POND
FERTILIZATION
Some pond owners will be interested
in knowing whether the higher fish yields
from fertilized ponds offset the cost of the
fertilizers.
At current (1960) prices quoted by
dealers in farm fertilizers, the treatments
used on the Dixon Springs ponds in 1947—
1949 would cost approximately $10 per
surface acre of water per year; the various
treatments used on the three ponds in
1950 would average close to $15 an acre,
and the treatments used in 1951-1953
would cost $20 per acre per year. In the
following computations, cost for fertiliz-
ing the ponds does not include wages for
men to do the mixing and spreading.
For the 5-year period 1948-1952, the
average annual hook-and-line yield (bass
and bluegills combined) from the ferti-
lized ponds was 48 pounds per acre and
from the control ponds 25 pounds per
acre, table 16. Although the fertilized
ponds were fished somewhat more heavily
than the controls, we will assume that
most of the 23 pounds greater annual
yield of the fertilized ponds was attrib-
utable to fertilization. Dressed weights of
bass and bluegills would amount to about
two-thirds of their live weights. The 23
pounds additional fish yield would there-
fore shrink to about 15 pounds in dress-
ing. The average yearly cost for fertilizer
over the 5 years, 1948-1952, was about
$15 per acre; therefore the cost of the
extra yield was approximately $1.00 per
pound of dressed fish.
Using data in table 16, we can make a
similar computation for the same period
for certain fertilized and unfertilized
ponds having nearly equal fishing pres-
sures: Lauderdale and Phelps to repre-
sent the fertilized ponds, Wells and Boaz
the untreated ponds. The total fishing
pressure for the two fertilized ponds (164
hours per acre per year) was nearly the
same as that for the two control ponds
(157 hours per acre per year). The per-
acre yield averaged +7 pounds annually
from the two fertilized ponds, 28 pounds
annually from the two controls, a differ-
ence of 19 pounds as live fish or 13
pounds as dressed fish. Here the larger
yield of the fertilized ponds was obtained
386 I_ttrinois NATURAL History SurvEY BULLETIN
at a cost of about $1.15 per pound of
dressed fish.
Using selected data in table 15, we can
compare costs for the periods of compara-
tively light and comparatively heavy fer-
tilizer treatments. In the following com-
putations, we have omitted data for 1947,
as before, and have also omitted data for
1950, when the three ponds were ferti-
lized at three different rates. For 1948
and 1949, the annual yields from the
fertilized ponds averaged 15 pounds per
acre more than the yields from the con-
trols—10 pounds in terms of dressed fish.
Since the annual cost of fertilizer in 1948
and 1949 was about $10 per acre, the ad-
ditional yield of dressed fish cost approxi-
mately $1.00 per pound. For 1951 and
1952, the annual yield was 26 pounds
greater per acre in the fertilized ponds
than in the controls, or 17 pounds dressed
weight. The cost of fertilizer during this
period was about $20 an acre, making
the cost of the additional yield approxi-
mately $1.18 per pound of dressed fish.
Also, we can estimate the cost per
pound of fish attributed to fertilization
in each of + years by comparing the rec-
ords for Lauderdale and Wells, two ponds
that were fished at nearly the same rates in
most years, especially 1948-1951, and
were fished in nearly the same way by the
test anglers. As table 15 shows, the per-
acre yield of bass and bluegills from
Lauderdale was greater than that from
Wells by 20 pounds in 1948, 17 pounds
in 1949, 42 pounds in 1950, and 30
pounds in 1951. When we divide the ap-
propriate cost figures, $10 an acre in 1948
and 1949, $20 an acre in 1950 and 1951,
by the dressed weights (13, 11, 28, and
20 pounds), we find that the greater
yields from Lauderdale Pond cost ap-
proximately $0.77 a pound in 1948, $0.91
in 1949, $0.71 in 1950, and $1.00 in
1951.
In the vicinity of Dixon Springs, the
approximate retail price of dressed carp
from the Ohio River is 25 cents a pound,
of dressed channel catfish 60 cents a
pound. If we were to judge the pond
fertilization program at Dixon Springs
solely by the dollar and cents food value
of the fish produced, we should conclude
that fertilization was not economically
justified.
Vol. 27, Art. 5
However, as a rule pond owners will
not base their decisions to fertilize or not
to fertilize their ponds solely on economic
grounds. Instead, they will base such de-
cisions largely on the belief that fertiliza-
tion will or will not provide them and
their families with more fishing fun.
In some instances, the size of the pond,
the type of ownership, and the financial
position of the owner will influence the
decision. For example, a pond of an acre
or more might be left unfertilized and a
pond of one-half acre might be fertilized,
because the smaller pond requires a small-
er outlay for fertilizer. A pond owned by
a single individual might be left unferti-
lized and an equivalent pond owned by a
club might be fertilized, because the cost
of the club-owned pond can be borne by
several members and requires no great out-
lay for any one individual. A pond might
be left unfertilized if owned by a person
who has a small cash income, or who fishes
principally for food, and an equivalent
pond might be fertilized if owned by an in-
dividual who has a moderate or large cash
income, or who fishes principally for sport.
As the Dixon Springs experiment shows,
ponds seem to differ in their responses to
fertilization; fertilization might be eco-
nomically profitable in some ponds but not
in others.
ANGLERS’ EVALUATION
OF PONDS
While we have shown that pond ferti-
lization was of some benefit to bluegill
fishing, there is a question whether the
differences between fertilized and unfer-—
tilized ponds in the quality of fishing were
great enough to be detected by fishermen.
No comments were heard or reported that
would indicate that the permit fishermen
thought that Hooker and Phelps (the two
permit ponds that were fertilized) pro-
vided them with better fishing than the
unfertilized permit ponds or other unfer-
tilized ponds in the neighborhood. The
test anglers, who visited all six ponds at
weekly intervals, generally had the most
success at Lauderdale Pond. Their pref-
erences were recorded only after the 1952
fishing season, but it was obvious from our —
conversations with them that Lauderdale ~
was the favorite among the six ponds.
August, 1960
Charles R. Peters, test angler in 1952,
stated that Lauderdale had given him the
most pleasure, and he rated the other
ponds in the following order: Elam,
Phelps, Wells, Boaz, and Hooker. Thus,
he ranked the fertilized ponds first, third,
and sixth. Examination of his catch rec-
ords suggests that his reaction to various
ponds might have been affected more
strongly by his success in catching bluegills
than by his success in catching bass.
Use by the public was somewhat more
intensive for the two permit ponds that
were fertilized (Hooker and Phelps—
especially Hooker) than for the two that
were not (Boaz and Elam), table 20. It
seems doubtful, however, if catch rates
were enough higher for the fertilized
ponds to explain their greater popularity
with fishermen. Hooker and Phelps ponds
were seldom as good as the unfertilized
ponds for bass fishing and in some years
were not so good as one or more unferti-
lized ponds for bluegill fishing. “Time
spent by permit fishermen in the 6 years
of the experiment totaled 92+ hours at
Hooker, 374 hours at Phelps, 356 hours
at Boaz, and 217 hours at Elam. The 6-
year average catch-per-man-hour rate for
bass in the most heavily fished fertilized
pond (Hooker) was below the rate for
the least fished control pond open to the
public (Elam). The bluegill fishing in
Hooker was inferior to that in Elam in
terms of number of fish per hour but
essentially the same in pounds per hour.
The differences in fishing pressure on
the four permit ponds may have been re-
lated to the various inconveniences fisher-
men put up with in getting to and from
each pond, such as the number of gates to
be opened and closed, the number of
fences to be climbed, or the walking dis-
tance to the pond. Hooker Pond was the
easiest to reach, Elam Pond the most dif-
ficult. The inconveniences of reaching
Phelps and Boaz were about equal. Quite
possibly the availability of shade, ease of
walking around the ponds, and general
attractiveness of the ponds were factors
that made the fishermen decide to fish
certain ponds more often than others.
Fishermen were not guided to the ferti-
lized ponds by news releases or other
publicity; only a few of them knew that
some ponds were being treated.
HANSEN et al.: HooK-ANpD-LINE CATCH
387
SUMMARY
1. Six ponds, each of about 1-1%
acres, in southern Illinois were used in an
experiment, 1947-1952, to measure the ef-
fect of pond fertilization on sport fishing.
The effect of fertilization was measured
by the sizes of the fish caught, the annual
hook-and-line yields, and the catch rates
per fisherman-hour.
2. The ponds were stocked with large-
mouth bass 6 to 10 inches long (total
length) and bluegills about 1 inch long.
3. Three of the ponds were treated
with chemical fertilizers containing nitro-
gen, phosphorus, and potassium, in some
years at rates less than, and in others at
rates approximately equal to, the mini-
mum rate suggested for ponds in Alabama
by Swingle & Smith (1942:16-8). The
other three ponds (the controls) were not
treated.
4. Creel data were obtained through
(1) public fishing under a permit system
that allowed fishermen relatively free ac-
cess to four of the ponds and (2) test
fishing by anglers (one each year) em-
ployed by the Illinois Natural History
Survey to fish each of the six ponds for a
2-hour period each week.
5. In 1953, after the ponds had been
closed to fishing for a year, the fish in all
six ponds were killed with rotenone, and
a census was made of the fish population
of each pond.
6. Growths of filamentous algae, which
appeared on the fertilized ponds in some
years, were at times a hindrance to fisher-
men.
7. Dense stands of a water plant,
Chara spp., died in the fertilized ponds in
the first summer of treatment, while equal-
ly dense stands of this plant continued to
grow in the control ponds.
8. Blooms of plankton algae were den-
ser and more prolonged in the fertilized
than in the control ponds.
9. The bass taken from the fertilized
ponds averaged smaller but the bluegills
larger than those from the control ponds.
Bluegills of 8-8'™% inches were more com-
mon from fertilized than from unferti-
lized ponds.
10. During the 5 years of fishing for
both bass and bluegills (in the year after
the ponds were stocked, bluegills were too
388
small to be kept), the total harvest of
bass, by weight, was slightly less from the
fertilized ponds than from the controls;
the bluegill harvest from the fertilized
ponds was 2.7 times that from the con-
trols. The ratio by weight of bass to blue-
gills was 1:3 in the fertilized ponds, 1: 1
in the controls.
11. One of the fertilized ponds was
superior to all others in both bass and
bluegill fishing. The three fertilized ponds
ranked 1, 5, and 6 in terms of both num-
ber and weight of bass harvested per hour;
1, 3, and 4 in terms of number of bluegills
harvested per hour; and 1, 2, and 3 in
terms of weight of bluegills harvested per
hour.
12. There is a statistical possibility
that through chance alone the fertilized
ponds would have ranked better than the
controls as bluegill fishing ponds even if
no fertilizer had been used.
13. No well-defined year-to-year trend
in catch rates for bass was observed dur-
ing the experiment. The trend in bluegill
fishing in both fertilized and control ponds
was toward year-to-year improvement in
the first + years of bluegill fishing.
14. The two ponds, one fertilized and
one control, with the smallest total num-
ber of man-hours of fishing had the highest
catch rates of harvestable bass. Under
equal or nearly equal fishing pressures,
bass fishing was in some instances better
in the fertilized ponds, in other instances
better in the controls; bluegill fishing was
consistently better in the fertilized ponds.
15. In September, 1953, the standing
crops of bass and bluegills (all sizes) in
the three fertilized ponds averaged 292
pounds per acre, in the three controls 238
pounds per acre (ratio 1.2:1). The num-
Ittrnors NATURAL History SurvEY BULLETIN
Vol. 27, Art. 5
ber of bass 10 inches or longer was ap-
proximately the same in fertilized as in
control ponds; the number of bluegills
6 inches or longer was 1.3 times as great
in fertilized as in unfertilized ponds.
16. The hook-and-line yields of bass
and bluegills in 1952, the last year the
ponds were fished, were equivalent to 20
per cent of the 1953 standing crops in
the fertilized ponds and 16 per cent of
the standing crops in the control ponds.
17. Judged by the populations of fish
of desirable sizes present at the time of
the 1953 census (bass 10 inches or longer,
bluegills 6 inches or longer), the hook-
and-line harvest appears to have been
more efficient for bass in the control ponds
and more efficient for bluegills in the fer-
tilized ponds.
18. Surprisingly little correlation was
found between numbers of bass and blue-
gills of harvestable sizes in the ponds in
1953 and the record of fishing success in
the preceding years.
19. The fertilization program used at
Dixon Springs was of apparent benefit to
bluegill fishing but of doubtful benefit to
bass fishing; any benefits derived from
direct fertilization of ponds were in ad-
dition to benefits that may have resulted
from fertilization of the pond watersheds.
20. Comparison of yields from the
fertilized and unfertilized ponds at Dixon
Springs shows that the greater yields of
fish from the fertilized ponds were ob-
tained at costs estimated to range from
$0.71 to $1.18 a pound.
21. Whether the improvement in the
quality of bluegill fishing attributed to
fertilization was great enough to be de-
tected by fishermen is questionable for at
least two of the three fertilized ponds.
PETE RAST OOOR BE CLhEE D
Ball, Robert C.
1948. Recovery of marked fish following a second poisoning of the population in Ford Lake,
Michigan. Am. Fish. Soc. Trans. for 1945, 75:36—42.
1949. Experimental use of fertilizer in the production of fish-food organisms and_ fish.
Mich. State Col. Ag. Exp. Sta. Tech. Bul. 210. 28 pp.
Ball, Robert C., and Don W. Hayne
1952. Effects of the removal! of the fish population on the fish-food organisms of a lake.
Ecology 33(1) : 41-8.
Ball, Robert C., and Howard D. Tait
1952. Production of bass and bluegills in Michigan ponds. Mich. State Col. Ag. Exp. Sta.
Tech. Bul. 231. 32 pp.
Ball, Robert C., and Howard A. Tanner
1951. The biological e%ects of fertilizer on a warm-water lake. Mich. State Col. Ag. Exp.
Sta. Tech. Bul. 223. 32 pp.
Bennett, George W., and Gilbert F. Weiss
1959. Fishing pressure and the empty creel. Ill. Wildlife 14(3) : 8-9.
Brown, C. J. D., and Robert C. Ball
1943. An experiment in the use of derris root (rotenone) on the fish and fish-food organisms
of Third Sister Lake. Am. Fish. Soc. Trans. for 1942, 72:267-84.
Carlander, Kenneth D., and William M. Lewis
1948. Some precautions in estimating fish populations. Prog. Fish-Cult. 10(3) : 134-7.
Davis, H. S., and A. H. Wiebe
1931. Experiments in the culture of the black bass and other pondfish. Report of the United
States Commissioner of Fisheries for the fiscal year 1930, Appendix IX:177-203.
(U. S. Bur. Fish. Doc. 1085.)
Dugan, R. Franklin
1951. Fish production records on some West Virginia farm ponds. N. Am. Wildlife Conf.
Trans. 16:403-21.
Fehrenbacher, J. B.
1959. Characteristics of the soils on the Dixon Springs Experiment Station of the University
of Illinois College of Agriculture. Ill. Univ. Agron. Dept. Mimeo. AG1841. 5 pp., map.
King, Willis
1943. Lake management studies in the Sandhills Wildlife Management Area. Am. Fish.
Soc. Trans. for 1942, 72:204-11.
Krumholz, Louis A.
1948. Variations in size and composition of fish populations in recently stocked ponds. Ecol-
ogy 29(4) : 401-14.
1950a. Some practical considerations in the use of rotenone in fisheries research. Jour. Wild-
life Mgt. 14(4) : 413-24.
1950. Indiana ponds: their construction and management for fishing. Lake and Stream Sur-
vey of the Indiana Department of Conservation, Division of Fish and Game, and In-
diana University. (Ind. Univ. Zool. Dept. Contrib. 435.) 35 pp.
Maciolek, John A.
1954. Artificial fertilization of lakes and ponds: a review of the literature. U. S. Fish and
Wildlife Scrv. Special Sci. Rep.: Fish. 113. 41 pp.
Mortimer, C. H., and C. F. Hickling
1954. Fertilizers in fishponds: a review and bibliography. Her Majesty’s Stationery Office,
London. Colonial Office Fish. Pubs. 5. 155 pp.
Neess, John C.
1949. Development and status of pond fertilization in central Europe. Am. Fish. Soc. Trans.
for 1946, 76:335-58.
Patriarche, Mercer H., and Robert C. Ball
1949. An analysis of the bottom fauna production in fertilized and unfertilized ponds and
its utilization by young-of-the-year fish. Mich. State Col. Ag. Exp. Sta. Tech. Bul. 207.
35 pp.
Schaeperclaus, Wilhelm
1933. Textbook of pond culture: rearing and keeping of carp, trout and allied fishes. (Trans-
lated from the German by Frederick Hund.) U. S. Fish and Wildlife Serv. Fish.
Leaflet 311. 260 pp.
Smith, E. V., and H. S. Swingle
1939. The relationship between plankton production and fish production in ponds. Am. Fish.
Soc. Trans. for 1938, 68:309-15.
[ 389 ]
390 Intinois NATuRAL History Survey BULLETIN Vol. 27, Art. 5
1942. The use of fertilizer for controlling several submerged aquatic plants in ponds. Am.
Fish. Soc. Trans. for 1941, 71:94-101.
Smith, Lloyd L., Jr., and John B. Moyle
1945. Factors influencing production of yellow pikeperch, Stizostedion vitreum vitreum, in
Minnesota rearing ponds. Am. Fish. Soc. Trans. for 1943, 73:243-61.
Smith, M. W.
1952. Fertilization and predator control to improve trout production in Crecy Lake, New
Brunswick. Can. Fish Cult. 13:33-9.
1954. Planting hatchery stocks of speckled trout in improved waters. Can. Fish Cult. 16:1-5.
Surber, Eugene W.
1945. The effects of various fertilizers on plant growths and their probable influence on the
production of smallmouth black bass in hard-water ponds. Am. Fish. Soc. Trans. for
1943, 73:377-93.
1948a. Fertilization of a recreational lake to control submerged plants: effects of fertilization
program upon bathing, boating, fishing. Prog. Fish-Cult. 10(2) :53-8.
1948b. Increasing production of bluegill sunfish for farm pond stocking. Prog. Fish-Cult.
10(4) :199-203.
Swingle, H. S.
1945. Improvement of fishing in old ponds. N. Am. Wildlife Conf. Trans. 10:299-308.
1947. Experiments on pond fertilization. Ala. Poly. Inst. Ag. Exp. Sta. Bul. 264. 34 pp.
Swingle, Homer S., and E. V. Smith
1941. The management of ponds for the production of game and pan fish. Pp. 218-26 in A
symposium on hydrobiology. University of Wisconsin Press, Madison. ix +405 pp.
1942. Management of farm fish ponds. Ala. Poly. Inst. Ag. Exp. Sta. Bul. 254. 23 pp.
Thompson, David H.
1941. The fish production of inland streams and lakes. Pp. 206-17 in A symposium on hydro-
biology. University of Wisconsin Press, Madison. ix + 405 pp.
Thor, A. U., and W. C. Jacob
1955. Percentage of soil samples by counties testing very low, low, slight, medium, high, and
very high in Illinois, 1955. Ill. Univ. Agron. Dept. Mimeo. AG1750a. 4 pp.
Zeller, Howard D.
1953. Nitrogen and phosphorus concentrations in fertilized and unfertilized farm ponds in
central Missouri. Am. Fish. Soc. Trans. for 1952, 82:281-8.
t
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ILLINOIS NATURAL HISTORY SURVEY
Bulle tin Printed by Authority of Ke -
the State of Illinois
Sex Ratios and Age Ratios
in North American Ducks
FRANK C. BELLROSE
THOMAS G. SCOTT
ARTHUR S. HAWKINS
JESSOP B. LOW
STATE OF ILLINOIS
Orro Kerner, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
WILiiaM SyLvester Wuire, Director
_ NATURAL HISTORY SURVEY DIVISION
Hartow B. Mus, Chief
NATURAL
PO i es hi UWIOTADYV Gitrncure
ILLINOIS NATURAL HISTORY SURVEY
Bulletin
Volume 27, Article 6 rr
Printed by Authority of
August, 1961 the State of Illinois
Sex Ratios and Age Ratios
in North American Ducks
meANK C. BELLROSE
maAONMAS G. SCOTT
me PHUR S. HAWKINS
aero) P B. LOW
Beer AG neh Ou lel I N-OoLss
Otto KERNER, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
WILLIAM SYLVESTER WHITE, Director
NATURAL HISTORY SURVEY DIVISION
Hariow B. MI ts, Chief
Urbana, Illinois
STATE OF ILLINOIS
Orro Kerner, Governor
DEPARTMENT OF REGISTRATION AND EDUCATION
Wituram Sytvester Waite, Director
BOARD OF NATURAL RESOURCES AND CONSERVATION
Wituam Sy.vesteR Waite, Chairman; A. E. Emerson, Ph.D., Biology; Watter H. Newnouse, Ph.D., Geology;
Rocer Apams, Ph.D., D.Sc., Chemistry; Rosert H. Anperson, B.S.C.E., Engineering; W. L. Everitt, E.E., Ph.D.,
Representing the President of the University of Illinois; Detyte W. Morris, Ph.D., President of Southern Illinois
University
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Jack A. Exxuis, M.S., Project Leader*
Bossie Jor Verts, M.S., Project Leader*
Ratpeuw J. Exris, M.S., Project Leader*
Wituiam L. Anperson, B.S., Assistant Project Leader*
James A. Harper, M.S., Assistant Project Leader*
Davi A. CasteeL, B.S., Assistant Project Leader*
GeraLtp G. Montcomery, M.S., Research Associate*
P. J. Rao, B.V.Sc., M.A., Research Assistant*
Ann C. V. Houmes, B.S., Research Assistant*
T. U. Meyers, Research Assistant*
Sruart H. Mann, B.S., Research Assistant*
Ricuarp W. Lurz, M.W.M., Research Assistant*
Ricuarp D. Anprews, M.S., Field Mammalogist*
Keirn P. Daupuin, Assistant Laboratory Attendant*
Section of Publications and Public Relations
James S. Ayars, B.S., Technical Editor and Head
Buancue P. Younc, B.A., Assistant Technical Editor
Epwarp C. Visnow, M.A., Assistant Technical Editor
Witmer D. Zenr, Assistant Technical Photographer
Technical Library
Rutn R. Warrick, B.S., B.S.L.S., Technical Librarian
Nett Mires, M.S., B.S.L.S., Assistant Technical
Librarian
CONSULTANTS: Herretorocy, Hosart M. Situ, Ph.D., Professor of Zoology, University of Illinois ; Parasiroocy,
Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University of Illinois;
Witpuire Researcu, Witrarp D. Kuimstra, Ph.D., Professor of Zoology and Director of Co-operative Wildlife
Research, Southern Illinois University.
*Employed on co-operative projects with one of several agencies: University of Illinois, Illinois Agricultural
Extension Service, Illinois Department of Conservation, National Science Foundation, United States Department of
Agriculture, United States Fish and Wildlife Service, United States Public Health Service, and others.
This paper is a contribution from the Section of Wildlife Research.
(08324—6 M—10-60) a 2
Nor
FOREWORD
| ee present publication illustrates
again the importance of continuing
certain types of research over a long period
of time in order to get data which allow for
significant deductions to be made. Further,
as the investigation reported here is in a
sense pioneering work, much thought has
had to go into data analysis, into weighing
the importance of data, and into attempts to
find the significance and relative importance
of the many facts discovered. These opera-
tions have necessitated the delay of publica-
tion until it was felt that the data and con-
clusions could withstand the inspection of
waterfowl scientists and other biologists
and, more importantly, contribute signifi-
cantly to our understanding of North Ameri-
can waterfowl.
Certainly, the analysis of the data and the
developing of the philosophy of the place of
sex ratios and age ratios in population me-
chanics was not an easy task; the data have
been about as abstruse as any collected in
waterfowl research.
The project was conceived by Arthur S.
Hawkins in 1938, while he was employed by
the Illinois Natural History Survey, and
great credit for far-sightedness must go to
him. It must be remembered that, at the
time of the project’s initiation, even good
aging techniques were still to be perfected.
When Mr. Hawkins entered the armed
forces in 1941, Mr. Bellrose took over the
study. Dr. Low contributed to the project
in Illinois from 1941 to 1943 and furnished
Utah data after he left Illinois.
Through the last 20 years, Mr. Bellrose
has carried the brunt of the load, and in re-
cent years Dr. Scott has contributed im-
measurably to data analysis and the prepara-
tion of the study for publication, as well as
arranging with the National Science Foun-
dation for the financing of publication costs.
Others, mentioned in the text, have given
unselfishly of their time and talents.
Last, but by no means least, we should
mention the long hours—often extending into
the night—spent by James S. Ayars, Tech-
nical Editor, in working with the authors
and the data. His was, as usual, a heavy
and significant contribution.
It is my hope, as well as that of the au-
thors, that this contribution will be of value
in the understanding and the management
of waterfowl populations over a wide area
and for a long time to come.
Hartow B. Mitts, Chief
Illinois Natural History Survey
Urbana, Illinois
Trapping and banding ducks at the Chautauqua National Wildlife Refuge near Havana,
Illinois, November, 1939,
CON TEN TS
BEeEOWLENDGMENTS AND SOURCES OF Dara’. fi. 0.0. Tj cncscens wane Obes endeeeua- 391
METER ets rete yrs he die eae vk ver UREA, OE RA aa oO ee ee 392
Mere yee USEC CEGA(T: SEVICLES Vos) 3 af elcteieiood wack Eas apes ohh wc cle Snes 393
eM ESD hn tM C9 ANG 9 PE crery ds Shas DE Ue Sk De eo ee ee 394
rimemrenniations for Sex Watios: «2s 65.45. mcs osoec bE olin oR Ue 396
mrammeation, oink tapped Duke yy. is. Da. Peele ses siaoas a8 «sa tees one
EP EE EL MaOL La Ute © BARS 4 hy. asthe aes’ ok Woe AE ee eee 400
Re ME SCR UUEIONGS © 0i.0 0 RMR toa Telok ee hele ye See 401
peerattrerinin OF Wisease, VichIMIs: :s/:. 00 Vio... d5e Che os ne oe nee See ee 402
eereememn Oitterent, Age “Classes... oo .adis a eidios boo v4 ee Dee See 402
MERE TERMS ORT IR AOS MySite ote Pile uk Ga Mia aii at POM cel cae oR ea 402
eR eRMES ER TEC LERIVS OPE 0s Sd co, wi Sh UA oe, ve ee A EL 403
(BT TRESS ys 20 ES eno aa Rn SR ne vee SP 403
rea TINS MAAS y : 6 51 adrace Balog de Cag OS aioe Se Us wk i ee 405
Peer ar Aations stile Sex RALOSs sc ida. .'e5.¢0 sees calaic yee vl 4 ane Peace ores 408
Pee ee ese iE Akl ttal VV IMECL <<< Gordo atic ake « Sota ek Sona FE oc oe NA ee 408
Cy SUE ERPS AT a LN rol Dv or ag i mc POR gee Oe 411
Mombanesunuthe Isteeding Seasons << 2.6.4.0. ces vs twee k eae oe ORE e een 416
SPeUreM NN TEIAtIOnS I. SEX RATIOS. ¢ 20004. <'% 2c os eau wuha woe ss sv oath eeetas 419
Mima actors Affectino sex Ratios...... 0... 6ceccs'etscess basesecueeanee es 420
Se MOMRAMUTO ME ANIMES LS 2). 8c 6 ETE pea, Pack bale w ha icthew Beas. 3 Rd ek 5 TM 421
et ere REIT OS eed chs Shanice 6 dye ces ween a hk PA Rae edie atiocs he ee 421
) TEGIEOS HIS MO7a 1a. Ploy es e222 (10 Cy ean gn eA Dea a oe 424
Pememirural ©perations and Sex Ratios ss... 4.46 cs. 4. is cas dee wetin es eenees 425
et ANE LEIOS). fcc aiercig 5 o.34s he Aaaoh SULA ee SDA ao Me PER lt eee 425
Paat OTA WV UOLEALLCY, a ACEOES.. a istcsn es sade cs 4m lee ahah ee = Belen, we ae bene 426
pueeeatios and Age Composition of Populations........<0....6..0ceeecscneaees 426
Meera vot surplus Drakes. oo o..< Sal sfed oa oe g he ebs vow avs obuule a Mate te 427
Beweieatins as. \Vieasures of Production 2%... sc0cc 5) eb ecb ae ee ols oe oer ee ed 428
RTE 2 S'S ES 8 ea EP OS ners ge eed rane nS ere Seah ee 2 430
Bee CHAE AP ye at Ha ed cS of os ae shins eaa = al -as lax nue a Ger ale Raced al muslin Makate e 430
Si eR EN? RULER VAS Re 0 aN fc Sad yO Ae cP eal nes Fo -6 ond a wee ae vias RE ee 431
Peeoomnatians ot Erappen DUCKS... ein sane ne 'n 06 ue dns teaa eee oe ee eer ee 431
Menocciian “ole biinters BAGS sac «oe oc io' nice aceionia is nav v5.8 50 8 Ro ane Doe aans eo 435
Pier a pranhOs LONSEASE. NW ICEIENS cca, «or <:k tos vravagalo Oa Scam Cordele Makan ee 439
Nessie ariations’ in’ ee KMatlOSs oslo. gels voor eot ge been wees UM Ea ets 440
eemimaley Atiations. it AoE! RACIOS 5, \'ueerte 4+ Sr0e< 2 Sfo's @ ayaie Dale niece eee ae 444
Par Ml eens ek ele sce tie aT Ee LOE RENE a RN a nk aN ee aes ee a eae 444
MOE ie HENLE pee an <9 hel w oie! Sno avahe one bree IRD ENDS re gueneee eee ae a 447
PURI RES AY Pet UOs NOC), IRABLOS vps die ic-c:< 5, dba eens te olor seig ee roto eee a ETS eaeae eee 449
ee rs ved ale ie ts tna! un acne ol es chats bb ayicte ve tate dustin MONE eke okieans anise nao 451
Defoe 9 82 | a, a ae Or eR oP ere Re nate Shee ne 451
olmrea pean Pot Mein va, 2 Seg ee sles ap wic ents ao ks es ee eae rama ate 451
Aaceeatinsas Wieasures ot PFOGUCLION:. <5 6.6 6.cc< viet ered oncclene ene scelaere ety ryes ft 454
Pedauetione Andee nV ITONiient is <ts2 Aude Se ere Sk OR LAD Moe eee eee 458
pcoductiotoun Dikterent SPeCleS...\. << c00.c0% sca s e202 2 on ees sree Eee Bae 466
Aap ation, Population. Managements: . 2462 vans leds oe Sele oe sas op eee 466
NST Fe ce fhe A tons chs lace di'eve bie oa nde (ele el peuew ese als sens oe Seren 468
Determining the sex and age of ducks killed by hunters in the Illinois River valley,
November, 1952.
Sex Ratios and Age Ratios
in North American Ducks
MaeaNK UC “BEE LROSEW PHOMAS .G,
foe UR SS. HAWKINS,
ANAGEMENT of waterfowl
includes the intelligent manipu-
lation of their populations. The
sex classes and age classes of various spe-
cies of ducks constitute measurable ele-
ments of the populations. ‘The present
study deals primarily with sex ratios and
age ratios and the ways in which they re-
late to population productivity. Nearly
three decades ago Leopold (1933:165-6)
wrote: “All measurements of either game
population or game productivity are en-
hanced in their significance and value if
the sex and age as well as the number of
individuals be determined.”
Although observations on the age ra-
tios of ducks have been recorded for more
than a decade and on the sex ratios for
more than two decades, the true relation-
ship of these ratios to productivity has not
been well understood. Much of the difh-
culty in understanding this relationship
has stemmed from observed differences in
sex and age ratios between species, re-
gions, and seasons. Often the reported
samples have favored one sex or age Class
so markedly as to indicate bias.
Some investigators of sex ratios in
waterfowl have pointed out mathematical
bias resulting from shortcomings in the
techniques used and biological bias result-
ing from unusual responses of the birds
to seasonal changes. Early in this study
it was apparent that age ratio data were
subject to bias resulting from the same
causes. Moreover, there appeared to be
additional causes for bias in the data re-
lating to both sex and age ratios. Despite
many difficulties in obtaining reliable data,
progress has been made in interpreting
the role of sex and age ratios in the pro-
ductivity of waterfowl.
*Frank C. Bellrose and Thomas G. Scott are members
of the staff of the Illinois Natural History Survey. The
other two authors were members of the staff in the initial
stages of the project reported here. Arthur S. Hawkins
is now Biologist, United States Fish and Wildlife Service,
stationed at Minneapolis, Minnesota; Jessop B. Low is
Leader, Utah Cooperative Wildlife Research Unit, Utah
State University, Logan.
16 Ol Wi,
AND JESSOP B. LOW*
In this paper, sex ratios are expressed
usually as the per cent of a population
consisting of drakes, the ratio of hens to
drakes, or the number of drakes per hen;
age ratios as the per cent of a population
consisting of juveniles (ducks that have
reached the flying stage but have not com-
pleted 1 year of life), the number of juve-
niles per adult, or the ratio of adults to
juveniles.
The statistical significance of differ-
ences among samples or among assumed
ratios was determined by either making
chi-square tests or referring to tables pre-
sented by Mainland, Herrera, & Sut-
cliffe (1956). These methods assume
that the samples taken were independent
observations of the characteristics being
measured and that the samples were taken
from homogeneous populations. It seems
likely that often these assumptions were
not entirely met. Therefore, the results
of these tests should be viewed cautiously.
In those instances in which there is a very
low probability that the differences could
have been due to chance, it seems very
likely that the differences were real.
Technical names and all but one of the
common names of ducks discussed in this
paper are from the Fifth Edition of the
Check-List of North American Birds (An-
onymous 1957). Because of its wide us-
age among hunters and its inclusion in
the Fourth Edition of the Check-List, the
name baldpate was used in place of 4 meri-
can widgeon. The listing of species in the
tables is in accordance with the phyloge-
netic arrangement that was in use at the
time the greater part of the study reported
here was being made.
ACKNOWLEDGMENTS AND
SOURCES OF DATA
The study on which this paper is based
was begun in 1938. Most of the data pre-
sented here were collected by personnel
of the Illinois Natural History Survey
[sof]
392
from inspection of trapped ducks and
bagged ducks taken in Illinois from early
autumn of 1939 through 1959. Other ex-
tensive data were obtained as follows:
from Arthur S. Hawkins and employees
of the Delta Waterfowl Research Station
and the Canadian Wildlife Service, who
checked the age and sex of ducks in Mani-
toba in 1946 and _ several subsequent
years; from Hawkins and John J. Lynch
of the U. S. Fish and Wildlife Service
and Frank C. Bellrose, who checked hunt-
ers’ bags in the Stuttgart, Arkansas, area
at various times from 1946 through 1959;
from Jessop B. Low, who obtained bag
inspection data in Utah in 1943 and 1944;
and from Noland F. Nelson of the Utah
Department of Fish and Game, who con-
tinued this work from 1946 through 1950.
Data obtained from biologists other
than the authors of this paper have been
acknowledged, when possible, in connec-
tion with the table or graph presenting the
data. Uncredited data from certain areas
should be ascribed to the individuals
listed below: John M. Anderson, data
from Winous Point Gun Club, near San-
dusky, Ohio; George C. Arthur, Illinois
Department of Conservation, data from
the Mississippi River in Illinois; Merrill
C. Hammond, U. S. Fish and Wildlife
Service, data from North Dakota; L. R.
Jahn, Wildlife Management Institute, and
Ralph Hopkins, Wisconsin Conservation
Department, data from Wisconsin; Her-
bert J. Miller and personnel of Pittman-
Robertson Project No. 45-R, Michigan
Department of Conservation, data from
Michigan; Charles T. Shanks, Missouri
Conservation Commission, data from Mis-
souri; Harvey W. Miller and John H.
Wampole, formerly with the Nebraska
Game, Forestation, and Parks Commis-
sion, data from Nebraska; T. Stuart
Critcher and Yates M. Barber, North
Carolina Wildlife Resources Commis-
sion, data from North Carolina; and
Charles K. Rawls, Jr., ‘Tennessee Game
and Fish Commission, data from Tennes-
see.
Roberts Mann, David H. Thompson,
and John Jedlicka of the Forest Preserve
District of Cook County, along with per-
sonnel of the Illinois Natural History
Survey, co-operated in the banding pro-
gram at McGinnis Slough, Cook County,
Intinoris NatrurAL History Survey BULLETIN
Vol. 27, Art. 6
Illinois. Robert D. Crompton and other
field assistants of the Illinois Natural
History Survey conducted the banding
programs at Lake Chautauqua, Mason
County, Illinois.
Aelred D. Geis of the U. S. Fish and
Wildlife Service and Stuart H. Mann of
the Illinois Natural History Survey as-
sisted in the statistical analysis of the sex
and age ratio data and gave valuable sug-
gestions for improving the manuscript.
George H. Kelker of Utah State Univer-
sity read the manuscript and made helpful
comments. Mrs. Frances D. Robbins,
formerly with the Illinois Natural His-
tory Survey, and Ralph E. Yeatter, now
and for many years a member of the Sur-
vey staff, aided in the preparation of the
paper. James S. Ayars of the Natural
History Survey edited the manuscript.
Appreciation is extended to all who
assisted in the gathering of data and the
preparation of the paper.
Publication of this paper was made pos-
sible through financial assistance from the
National Science Foundation: Grant
NSF-G11143.
SEX RATIOS
For several decades, waterfowl hunters
and ornithologists have noted a lack of
balance in the ratios of drakes to hens in
the populations of various species of
ducks. Some of them have called atten-
tion to the greater numbers of drakes and
have expressed concern because they be-
lieved the ‘‘extra” drakes served no useful
reproductive function. Others have called
attention to the unequal sex ratios as pos-
sible signs of sick populations.
For example, Leopold (1933:111) in
discussing sex ratios in ducks stated:
All of Lincoln’s evidence points toward the
existence of a seriously deranged sex ratio.
How long it has existed, or what causes it,
remains unknown. It is barely possible, of
course, that it always has existed, and repre-
sents a normal condition, but this seems im-
probable, especially in a group of species less
strongly monogamous than most other birds.
The reader should note that here again we
have an excess of males associated with a
known decline in population, and a known
trend toward adversity in recent climatic and
range conditions.
Although unbalanced sex ratios among
ducks were noted many years ago, little
August, 1961
research was done on the subject until
about 1940.
Determining the causes of unbalance in
sex ratios among ducks is difficult because
the birds have a high degree of mobility
and because each of the species involved
has its own population structures, migra-
tion schedules, and migration routes. Also,
in some species the drakes and hens do
not migrate at the same times or along
the same routes. In short, the determina-
tion of sex composition in duck popula-
tions presents a difficult sampling problem
complicated by differences in species, sea-
sons, and places, and by sampling tech-
niques that are inadequate.
Previous Sex Ratio Studies
In order to provide for an understand-
ing of the various ways in which calcu-
lated sex ratios may vary with sampling
methods or with location and season of
observation, a brief review of the most
important papers on waterfowl sex ratios
is offered.
Over 25 years ago Lincoln (1932)
asked and answered the question: ‘‘Do
drakes outnumber susies?”’ Since that
time, observers have agreed unanimously
with Lincoln’s answer that drakes out-
number hens in the North American duck
population. ‘There has been but little
agreement, however, on the degree of un-
balance or the reliability of the various
methods used to obtain sex ratio data.
Lincoln (1932:3, 16) assumed that
drakes and hens were taken in traps in the
same proportions in which they occurred
in nature but that hunters selected drakes
in preference to hens. He found that
drakes comprised 59.7 per cent of 40,904
ducks representing 10 species trapped
and banded in North America and _ in-
cluded in his study.
From extensive observations made dur-
ing trapping and banding of ducks at Av-
ery Island, Louisiana, during 1934-1938,
Mcllhenny (1940:91-3) concluded that
there was a seasonal variation in sex ra-
tios and presented data on the pintail
(Anas acuta), blue-winged teal (Anas
discors), ring-necked duck (Aythya col-
laris), and lesser scaup (Aythya affinis)
which showed that, while drakes consist-
ently outnumbered hens, the difference
was less marked in autumn than in winter
BELLROSE et al.: SEX Ratios AND AGE RATIOS
393
and spring. Of 51,884 ducks of nine spe-
cies banded by Mcllhenny, 67 per cent
were drakes, and only 33 per cent were
hens. Mcllhenny (1940:87), like Lin-
coln, believed that hunters — selected
drakes in preference to hens.
In Minnesota, Erickson (1943 :32-3)
recorded the sex of 6,008 ducks of 15 spe-
cies observed in the field during the
spring migration periods of 1938, 1939,
and 1940; drakes comprised 65 per cent
of the populations sampled. There were
significant differences between sex ratios
in two periods, one early and one late in
the spring. Erickson concluded from his
study that “the disparity of the sex ratios
obtained by trapping have been overem-
phasized.”
On the basis of limited data, Petrides
(1944: 565-67) concluded that the avail-
able evidence, though inadequate, indi-
cated “that banding traps may be less at-
tractive to female than male ducks.’ He
compared the sex ratios of 6,359 banded
ducks—mallard (Anas platyrhynchos),
pintail, and lesser scaup—killed by hunt-
ers, and represented by return cards in the
files of the U. S. Fish and Wildlife Serv-
ice, with the sex ratios of trapped ducks
of the same species as recorded by Lin-
coln (1932:16) prior to hunting. He
found that there was “negligible sex se-
lection by hunters.” Sight observations
that Petrides (1944:568-70) made in and
near Washington, D. C., in 1941-1943 on
25,870 ducks (most of them pintails)
showed 56 per cent were drakes. After
examination of the locations of banding
stations, Petrides suggested that early
studies of the sex ratios of banded ducks
“might have been affected by faulty geo-
graphic sampling as well as by selectivity
of traps.”
On the West Coast, Beer (1945:118-
20) found that sex ratios obtained from
field observations were more reliable than
those obtained from inspection of hunters’
bags. He reported that the calculated sex
ratios for most species of ducks remained
the same throughout winter as well as
early and late in the period of migration.
His data, which included 10,180 ducks of
15 species, showed a drake to hen ratio of
1.18:1 (54 per cent drakes).
In eastern Washington, Yocom (1949:
226-7), after comparing sex ratios from
394 Intrinois NAatTuRAL History Survey BULLETIN
hunters’ reports (176 males to 100 fe-
males) with those from field observations
in November and December (118 males
to 100 females), decided that selective
shooting accounted for the larger num-
bers of drakes among mallards reported
by hunters. In 8,805 mallards observed
in the field from late November to
mid-March, the drake to hen ratio was
109: 100.
Johnsgard & Buss (1956:384-5) took
sex ratios of ducks in central Washington
from February 15 to May 16, 1954. From
their observations they concluded:
Sex ratios of any single species varied at
any given time as a result of at least two in-
fluences. First, sex ratios were more unbal-
anced on areas subject to human disturbance.
Paired birds were the first to flush and the
last to return to a disturbed area....
Second, sex ratios during any single period
varied with the characteristics of the habitat.
After taking sex ratios of four species
of ducks in the Netherlands, Lebret
(1950:17) stated:
Sex-ratio field counts of migratory duck do not
reveal the sex-ratio in the species as a whole,
but only differences in the migration of the
sexes—provided the difficulty of different sex
distribution within the sample areas had been
eliminated.
Each of the methods of sampling for
sex ratios—field observations, trapping,
and inspection of hunters’ bags—has in-
herent weaknesses that produce biased
data. Only by determining the magnitude
of bias and correcting for it when neces-
sary can the degree of unbalance in sex
ratios among waterfowl be ascertained.
Sex Criteria
The sex of a duck may be determined
by one or more of the following charac-
teristics: (1) plumage, (2) bill color, and
(3) presence or absence of a penis. As a
means for distinguishing sex, each charac-
teristic has advantages and disadvantages.
In most species of ducks, differences in
the plumage color between drakes and
hens usually make possible the distinguish-
ing of sexes at considerable distances in
the field. However, at certain times of
the year, the plumages of hens and drakes
of most species are so similar as to make
field separation difficult or impossible.
Drakes in eclipse plumage are so simi-
lar in appearance to hens of the same spe-
cies that usually a bird in this condition
Vol. 27, Art. 6
must be in the hand before the sex can be
ascertained. The sex of ducks in juvenile
plumage also is difficult to ascertain un-
less the birds are in the hand; in some
species no plumage differences are visible
until the ducklings are several weeks old.
For example, in the wood duck (dix
sponsa), the two white bars which extend
upward behind each eye of the male and
serve to distinguish the male from the fe-
male do not begin to appear until the
duckling is + to 5 weeks of age. In the
redhead (dAythya americana), the male
first shows the distinguishing marks, deli-
cate white vermiculations of the scapulars
and interscapulars, at an age of 5 to 6
weeks (Weller 1957:19). In the canvas-
back (Aythya valisineria), the male can
be separated from the female by gray ver-
miculations on the scapulars of the male
at the age of about + weeks (Dzubin
1959 :289).
The black duck (Anas rubripes) is the
only common duck in the United States in
which drake and hen adult plumage at
all times of the year are so similar as to
make difficult the distinguishing of sex.
Several other ducks have plumages in
which the drake and hen are very similar,
but these kinds are generally uncommon
and have very limited ranges in the United
States. They include the black-bellied
tree duck (Dendrocygna autumnalis),
fulvous tree duck (Dendrocygna bicolor),
Mexican duck (Anas diazi), and mottled
duck (Anas fulvigula).
The bill color is of most value for dis-
tinguishing the sex in certain species when
the individuals are juveniles or are adults
in eclipse plumages. On the bills of most
species there are fine shades of color dif-
ference that distinguish between the sexes.
In certain dabbling species, the hen is
characterized by dark dots, spots, or
blotches at the base and sides of the upper
mandible; rarely are such markings found
on the bill of the drake. Species in this
category are the mallard, black duck, gad-
wall (Anas strepera), green-winged teal
(Anas carolinensis), blue-winged _ teal,
and shoveler (Spatula clypeata).
The most reliable characteristic for
sexing ducks in which the plumage does
not readily distinguish the sexes is the
presence or absence of a penis, fig. 1. The
technique of examining the cloaca for the
August, 1961 BELLROSE ef al.: SEX RaTIos AND AGE RATIOS 395
Fig. 1.—Waterfowl being sexed and aged by examination of cloaca; 4, juvenile male mal-
lard, with small penis; B, adult male mallard, with large penis; C, juvenile female mallard, with
closed oviduct and with bursa of Fabricius disclosed by feather probe (bursa present in juvenile,
both female and male, absent in adult); D, adult female mallard, with open oviduct (oviduct
open in adult female, closed in juvenile).
396
occurrence of the penis has been described
by Hochbaum (1942:302). Ducklings
only a few days old have been successfully
sexed by this method.
In the study reported here, trapped or
bagged ducks that could not be readily
sexed by plumage or by bill color were
sexed by cloacal characters.
Sampling Populations for Sex Ratios
In the present study, several methods
were used to sample waterfowl popula-
tions for sex ratios. These were (1) ex-
amination of trapped ducks, (2) inspec-
tion of ducks in hunters’ bags, (3) obser-
Intinois NATuRAL History Survey BULLETIN
Vol. 27, Art. 6
vation of ducks in the field, and (4) ex-
amination of disease victims. In endeavor-
ing to determine the true sex ratios exist-
ing among ducks in nature, we found that
certain biases were implicit in each
method. Biases in some methods were
such that they could be corrected or ad-
justed to the extent that fairly valid ra-
tios could be derived.
Following is a review of the four meth-
ods used in sampling duck populations
for sex ratios, the advantages of these
methods, and the disadvantages.
Examination of Trapped Ducks.—
From the start of trapping and banding
Table 1.—Drake percentages in mallards trapped and banded at the Chautauqua National
Wildlife Refuge, near Havana, Illinois, and in year-of-banding recoveries, 1939-1944 and
1947-1950. Preponderance of drakes or hens recovered is indicated by differences in per-
centage points: + for drakes, — for hens.
Ducks TRAPPED AND BANDED
— Total Number | Per Cent
Number Drakes Drakes
1939 Fey oo: 3,474 2,574 74.1
19603230 5,840 4,262 73.0
1940 ae 4,834 3,200 66.2
ri ae a 6,854 4,859 70.9
1943% 32 3e% 6,445 4,655 pie)
2 2 Ma ees ee 3,465 2,734 78.9
POF acca cian’ 1,786 1,481 82.9
1948S oe. 1,667 15332 79.9
[1 2 lege tee Spiers 3,254 2,478 76.2
TOROS A een 1,116 808 72.4
All years..... 38,735 28 , 383 7305
RECOVERIES IN YEAR OF BANDING
DIFFERENCE
nT ana a IN
Total Number | Per Cent | PERCENTAGE
Number | Drakes | Drakes Points
142 114 80.3 + 6.2
442 332 75e + 2.1
143 100 69.9 + 3.7
512 393 76.8 + 5.9
374 284 75.9 + 3.7
222 181 81.5 + 2.6
80 65 81.3 — 1.6
ey 15 88.2 + 8.3
128 99 Tisd + 1.1
68 51 75.0 + 2.6
2,128 1,634 76.8 + 3a
Table 2.—Drake percentages in black ducks trapped and banded at the Chautauqua National
Wildlife Refuge, near Havana, Illinois, and in year-of-banding recoveries, 1939-1944
1947-1950. Preponderance of drakes or hens recovered is indicated by differences in per-
centage points: + for drakes, — for hens.
Ducks TRAPPED AND BANDED
YEAR
Total Number | Per Cent
Number Drakes Drakes
1959 es inet 132 102 Tihsd
TOs eine tins 189 161 85.2
2 ey GO ean eae 549 329 59.9
Oar. saan: 507 348 68.6
TOR es 417 303 Fare |
19SEC abies 276 185 67.0
bo Sra ete | 174 133 76.4
ee 2 PR 112 7 Tg eed
7 ne | 571 381 66.7
PESO ec cue | 150 110 73.3
All years 69.5
RECOVERIES IN YEAR OF BANDING
DIFFERENCE
IN
Total Number | Per Cent | PERCENTAGE
Number Drakes Drakes Points
5 4 80.0 + 2%
13 10 76.9 — 8.3
fi 5 71.4 + 11.5
56 42 75.0 + 6.4
28 18 64.3 — 8.4
21 15 71.4 + 4.4
ceed eS ae Wes by Pa * aa
9 5 55.6 — 17.7
164 113 68.9 — 0.6
a
August, 1961
operations in 1939 at the Chautauqua Na-
tional Wildlife Refuge, near Havana, in
Mason County, Illinois, records were kept
of the sex of each duck that was trapped
and banded. In all of these records, the
relative numbers of drakes among the
mallards and black ducks were so high
as to arouse suspicion that the baited, fun-
nel-type traps being used were selective
for drakes, tables 1 and 2. At McGinnis
Slough, in Cook County, the relative
numbers of drakes among mallards and
black ducks taken in similar traps were
somewhat lower, tables 3 and 4, but they
were high enough to indicate that the
traps tended to take disproportionate
numbers of drakes.
Drakes made up about three-fourths of
the mallards taken in banding traps at
Lake Chautauqua in the years 1939-1944
and 1947-1950, table 1. Evidence that,
BELLROSE et al.: SEx Ratios AND AGE RATIOS
397
among mallards, the drakes are trapped
much more readily than the hens is found
by comparing figures derived from trap-
ping and banding (73.3 per cent drakes,
table 1) with figures derived from inspec-
tion of hunters’ bags (56.5 per cent drakes
for the years 1939-1950 in table 13, or
53.8 per cent drakes after a correction fac-
tor of 1.05 has been applied to compen-
sate for hunter preference for drakes).
Mallards entered the Lake Chautauqua
traps at the rate of 1.4 drakes to 1 hen.
The use of data derived by one method
to check on the data derived by another
is discussed in the section on inspection of
hunters’ bags.
Further evidence that mallard drakes
are trapped much more readily than the
hens is found by comparing the relative
numbers of birds of each sex that were re-
trapped in the same season at two Illinois
Table 3.—Drake percentages in mallards trapped and banded at McGinnis Slough, Cook
County, Illinois, and in year-of-banding recoveries, 1941-1947. Preponderance of drakes or
hens recovered is indicated by differences in percentage points: + for drakes, — for hens.
Ducks TRAPPED AND BANDED | RECOVERIES IN YEAR OF BANDING D
IFFERENCE
YEAR IN
Total Number | Per Cent Total Number | Per Cent | PERCENTAGE
Number Drakes Drakes Number Drakes Drakes Points
a ae 195. le "6205 21 Make 6627 4+ 4.9
MO ee ss 1,882 1,128 59.9 143 92 64.3 + 4.4
Msi is ats 3,009 1,922 63.9 138 78 56.5 = 7/4
a 1.778 967 54.4 168 100 59.5 + 5.1
EE i a DOG) 1,492 65.2 170 107 62.9 — 2.3
AG soa <s 1,624 860 53.0 126 61 48.4 — 4.6
i 970 556 Cvs) 56 37 66.1 + 8.8
Al] years...» 11,862 7,120 60.0 822 489 595 — 0.5
Table 4.-—Drake percentages in black ducks trapped and banded at McGinnis Slough, Cook
County, Illinois, and in year-of-banding recoveries, 1941-1947. Preponderance of drakes or
hens recovered is indicated by differences in percentage points: + for drakes, — for hens.
Ducks TRAPPED AND BANDED | RECOVERIES IN YEAR OF BANDING D 7
IFFERENCE
YEAR Pp aa
Total Number | Per Cent Total Number | Per Cent BOP NITENG IS
Number Drakes Drakes Number Drakes Drakes Points
es 659 406 61.6 38 26 68.4 + 6.8
ME. ss 1,069 645 60.3 91 47 Sythe 7 — 8.6
ae 962 595 61.9 44 24 54.6 — 7.3
MOA es. 852 490 S55) 93 55 59.1 + 16
HAS ww ew ce 716 462 64.5 54 42 I + 13.3
MPA 50. «a oe 2 629 385 61.2 38 24 63.2 + 2.0
ME ss. ns. 659 388 58.9 23 10 43.5 — 15.4
All years... 5,546 3,371 60.8 381 228 59.8 — 1.0
398 I_Ltinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 6
banding stations, tables 5 and 6. Chi-
square tests disclosed that the relative
number of drakes retrapped was signifi-
the sexes in proneness to enter traps. Haw-
kins found in banding blue-winged teals
near the Pas, Manitoba, in 1951 that 39.0
Table 5—Number of drake and hen mallards trapped and banded, and number and per
cent of each group retrapped at least once in the same season, at the Chautauqua National
Wildlife Refuge, near Havana, Illinois, 1940 and 1941. Sex selectivity of baited traps is indi-
cated by the ratio of drakes to hens among retrapped ducks.
NuMBER OF DRAKES RatTIo oF
Re-
Y p a
EAR ERIOD Trapped ENS TO
and aah d and Re-
Banded Banded TRAPPED Paani:
1940 | Oct. 11-24 793 168 507 16.4 | 1:1.29
Oct. 25—Nov. 7 591 111 102 229 1:6.48
Nov. 8-21 918 86 284 3.9 1:2.41
Nov. 22—Dec. 15 1939 110 667 6.5 1:0.87
Oct. 11-—Dec. 15 4,241 475 1,560 9.0 1:1 94"
1941 | Nov. 1-7 595 ey Ree 299 | gs | 2.7 aes
Nov. 8-21 563 97 17.2 218 19 8.7 1:1.98
Nov. 22—Dec. 5 1,476 115 7.8 716 33 4.6 1:1.70
Dec. 6-25 529 22 4.2 353 3 0.9 1:4.76
Not. 1-—Dec. 25 3,163 270 oa) 1,586 63 4.0 1:2.13+
*Probability of difference being due to chance less than 0.02 (X?=5.95, 1 d.f.).
{Probability of difference being due to chance less than 0.0005 (X*=33.67, 1 d.f.).
Table 6—Number of drake and hen mallards trapped and banded, and number and per
cent of each group retrapped at least once in the same season, at Spring Lake National Wildlife
Refuge, near Savanna, Illinois, 1946. Sex selectivity of baited traps is indicated by the ratio
of drakes to hens among retrapped ducks.
NuMBER OF DRAKES NumBer or Hens RaTIO OF
PER Per Re-
CENT CENT TRAPPED
OF OF
PERIOD = oa Weaeoe 1525; Re. tices ss
Banded | tapped Re- Banded | trapped Re- | pRappep
TRAPPED TRAPPED | Draxes
Oeer Waa. Sneed 173 117 67.6 121 53 43.8 1:1.54
Oceris ashe. See aoe 209 103 49.3 129 38 29.5 1:1.67 @
Nowe ok. se ence ee 445 171 38.4 258 75 29.1 1:1.32
Nov ha14io eae ao 568 129 22e7 367 72 19.6 1:1.16°8
Mang heat tr. acta aac 189 28 14.8 108 9 8.3 1:1.73 8
Oils Nov 21 ase octane 1,584 548 34.6 983 247 Ee BI 1:1.38*
*Probability of difference being due to chance less than 0.0005 (X?=25.39, 1 d.f.).
cantly greater than the relative number of
hens retrapped.
Records obtained from _ blue-winged
teals trapped and banded and later re-
trapped in 1944 at McGinnis Slough
(Mann, Thompson, & Jedlicka 1947:
141) indicate that, at that time and place,
there was no important difference between
per cent of the drakes and 31.5 per cent
of the hens trapped and banded were
later retrapped. |
The greater tendency for mallard
drakes than for hens to enter the baited,
funnel-type traps at Lake Chautauqua
was remarkably consistent through most
of the autumn; the drake percentage in
ose
i
August, 1961
traps increased as the drake percentage in
the population increased (indicated by bag
checks, fig. 2).
In the mallard and the black duck, dif-
ferences in behavior may contribute to dif-
ferences in numbers between males and
females trapped or retrapped. One differ-
80
75
70
65
60
PER CENT DRAKES
55
50
45
3rd
OCTOBER
2nd 4th Ist
BELLROSE et al.: SEX RATIOS AND AGE RATIOS
2nd
NOVEMBER
399
blind near the traps on Lake Chautauqua
showed that, when mallards were massed
around the traps, the drakes were more
forceful than hens in pushing their way
into the traps.
Chi-square tests of data in tables 1, 2,
3, and 4 indicate that in both the mallard
Trap Catches
Bag Checks
4th Ist 2nd
DECEMBER
3rd 3rd
Fig. 2.—Week-to-week changes in the drake percentage of the autumn flight of mallards in
Illinois, as indicated by two sampling methods: checks of mallards in hunters’ bags and inspec-
tion of mallards caught in banding traps. Bag data are for the Illinois River valley, 1939-1949 ;
trap data are for Lake Chautauqua, 1939-1944 and 1947.
ence in behavior is the greater aggressive-
ness of the drakes; this may occur because
of differences in food demands during the
fall. Studies on food consumption of
penned wild mallards (Jordan 1953:122)
revealed that, during the fall and winter,
drakes consumed 15 per cent more food
than did hens. Observations made from a
and the black duck the propensity of
drakes to enter traps was significantly
greater at Lake Chautauqua than at Mc-
Ginnis Slough. The population density
was much greater at Lake Chautauqua
than at McGinnis Slough. Consequently,
the competition for bait at trap sites was
greater, the aggressiveness of drakes was
400
greater, and the trap catch of drakes was
greater at Lake Chautauqua than at Mc-
Ginnis Slough.
Not all traps have been found selective
for drakes. Merrill C. Hammond, biolo-
gist of the U. S. Fish and Wildlife Serv-
ice, in an unpublished report prepared in
1949, stated that he captured more hens
than drakes in a gate-type trap placed on
shore adjacent to marsh vegetation in the
Lower Souris National Wildlife Refuge
in north-central North Dakota. He spec-
ulated that because of nesting activity
hens were more accustomed than drakes
to walking on land through tall vegeta-
tion; therefore, they would enter a trap
on the shore more readily than drakes.
Supporting evidence for Hammond’s
speculation was obtained by Hawkins at
Delta, Manitoba, in 1950. He found that
in two funnel-type traps placed only a
few yards apart, one in the water and the
other on land, the trap in water captured
2.2 drake mallards per hen, whereas the
trap on land captured only 1.5 drake mal-
lards per hen.
Inspection of Hunters’ Bags.—In-
spection of ducks in hunters’ bags in fall
and early winter for obtaining sex ratio
data was found to have some advantages.
Late-molting adult drakes can be sep-
arated from hens, which they resemble
during the eclipse molt, and the sexes of
juveniles can be distinguished; compari-
sons can then be made between sex ratios
of adults and those of juveniles. Avail-
able data indicate that most sex ratios de-
rived from inspection of hunters’ bags are
only slightly biased, usually in favor of
drakes.
Tendencies for hunters to bag propor-
tionately more ducks of one sex than those
of the other depend (1) partly upon the
chronology of migration of the ducks, (2)
partly upon the preferences of hunters,
and (3) partly upon hunting conditions
and upon skill of hunters.
Differences in chronology of migration
may expose birds of one of the sexes to a
greater number of hunters or make them
more vulnerable to hunting than birds of
the other sex.
A striking example of the relationship
between the chronology of migration and
shooting pressure was found in the red-
head. Adult drake redheads move from
I_ttrnoris NAaturRAL History Survey BULLETIN
Vol. 27, Art. 67
their breeding grounds in southern Mani-
toba to more northern marshes for molt- |
ing, while the hens remain on the breed-—
ing grounds, according to Milton W.
Weller in an unpublished report prepared
at the University of Missouri in 1954,
Because bag checks showed that adult
drakes comprised only a small proportion
of a large kill of redheads made in south-
ern Manitoba, Weller deduced that the
southward migration of adult drake red-
heads involved much longer flights than
the migration of adult hens. Evidence
suggesting that the migration of adult
drake redheads to the wintering grounds
consists of long flights is given by band re-—
coveries reported by Cartwright & Law
(1952:11), who showed a much lower
year-of-banding recovery rate for these
birds than for juvenile males or for fe-
males.
Geis (1959:256-7) found that, among
canvasbacks, adult hens and juveniles of
both sexes had a higher percentage of
band recoveries early in the hunting sea-_
son than did adult drakes, while adult
drakes had a higher percentage of band
recoveries on the wintering grounds than
did either adult hens or juveniles. Band
recovery rates indicate that adult drakes”
in the canvasback, like those in the red-—
head, make longer flights along migra
tion routes than do adult hens.
That hunters may prefer to shoot ducks
of one sex rather than those of the otheml
is shown by interviews with hunters and
by analysis of data on duck kill. It seems
logical to assume that hunters, faced with
a species having a drake more brillianeiaa
colored than the hen and given an equal
opportunity at birds of each sex, would
pick the more brightly colored bird, a)
Mcllhenny (1940:87) suggested.
In Illinois, the mallard and the black
duck have similar habits and behavior.
On the wing, the black duck drake is iden-
tical in appearance to the hen, whereas”
the mallard drake, during most of the Illi
nois hunting season, is readily distinguish-
able from the hen. =
That under certain circumstances hunt-
ers demonstrate a preference for drak *;
August, 1961
1944 and 1947-1950, tables 1 and 2.
The drake percentage among the birds
trapped can be compared with the drake
percentage among the birds represented by
band recoveries. “Too few black ducks
were banded to permit valid comparisons
each year; however, when the data for
the black duck were totaled for the 10
years of study, no marked hunter prefer-
ence for drakes was evident in this species.
In the case of the mallard, the preponder-
ance of drakes among the banded ducks
recovered indicated a consistent year-to-
year tendency for hunters to select drakes
to a somewhat greater extent than hens,
there being only 1 year (1947) in which
hunter preference for drakes was not evi-
dent.
In the period 1939-1950, the drake
percentage among 2,128 mallards reported
shot in the year they were banded (76.8
per cent) was shown by a chi-square test
to be significantly greater than the drake
percentage among 38,735 mallards that
were trapped and banded (73.3 per cent),
table 1. “These percentage figures indi-
cate that drakes were 1.05 times as likely
to be taken by hunters as were hens. This
estimate of the greater likelihood of mal-
lard drakes being taken by hunters can
be used as a correction factor to com-
pensate for hunter preference in calcula-
tions employing other data involving the
same species, the same area, the same pe-
riod of years, and the same time of year.
The ducks represented in table 13 were
mallards shot by hunters in approximately
the same area and times of year as those
represented in table 1. Calculations based
on data in table 13 show that for 1939-
1950, the period of years covered in table
1, 56.5 per cent of the mallards checked in
hunters’ bags were drakes. Allowance can
be made for hunter preference for drakes
by applying the correction factor 1.05 to
this percentage figure. The result is 53.8
per cent, which is believed to represent the
average drake component of the fall popu-
lations of mallards in the Illinois River
valley in the period 1939-1950.
That the degree to which hunters se-
lect drakes rather than hens may be in-
fluenced by hunting conditions and by
the skill of the hunters, as well as by per-
sonal preferences of hunters, can be
shown by comparison of band recovery
BELLROSE et al.: SEX RATIOS AND AGE Ratios
401
data from mallards banded at Lake Chau-
tauqua with similar data from mallards
banded at McGinnis Slough, tables 1 and
3. Bandings at Lake Chautauqua were
made in the heart of the duck hunting
club area of Illinois, where ducks were
comparatively numerous and where hunt-
ers, many of them experienced shots, could
afford to be selective of their targets.
Bandings at McGinnis Slough were in
an area where competition for ducks was
much keener than near Lake Chautauqua
and where hunters tended to shoot at ex-
treme ranges. Analysis of band recovery
data for mallards banded at McGinnis
Slough showed no hunter preference for
drakes, table 3.
Even hunters who have access to the
best shooting areas vary from year to year
in the degree to which they choose drakes.
At Stuttgart, Arkansas, in 1946, when
hunting conditions were unfavorable be-
cause high water had dispersed the ducks
through the swamps and when the bag
limit was seven ducks, drakes comprised
only 51.0 per cent of 3,350 mallards
checked in hunters’ bags. In the 1947
season, when hunting was much better in
the Stuttgart region and the bag limit was
only four, drakes comprised 59.5 per cent
of the 3,317 mallards checked. Of the
Stuttgart region in the hunting season of
1945-46, Hawkins, Bellrose, & Smith
(1946:398) wrote: “Hunting is so good
in the Grand Prairie area that the better
hunters can, and a few do, deliberately
select drakes.” In the sample of bagged
ducks they inspected, 55.8 per cent were
drakes.
Field Observations. — Observations
on living ducks in the field are a means
of providing sex data on large samples of
many species. With such data, no com-
pensation is needed for differences in trap
and hunter selectivity. It is almost impos-
sible, however, to make a sufficient num-
ber of random counts to insure an ade-
quate cross section of the population of a
flyway or other large area. Field counts
of the drakes and hens in duck popula-
tions are more readily taken in late win-
ter and early spring than at any other
time. Early in the fall the juvenile and
eclipse plumages make distinguishing be-
tween the sexes difficult, and hunting
activity at that time usually makes ducks
402
Table 7.—Drake percentages in pintails,
redheads, and lesser scaups observed in the
field on the Lower Souris National Wildlife
Refuge, North Dakota, 1948.*
Noumser | Per Cent
SPECIES Date or Ducks | Drakes
Pintail April 22 75 56
May 6 157 70
May 13 204 82
May 21 133 77
Redhead | May 6 66 53
May 13 143 61
May 21 137 58
Lesser April 22 243 59
scaup | May 5 and 6 486 61
May 13 120 68
*Unpublished data collected by Merrill C. Hammond,
Biologist, U. S. Fish and Wildlife Service.
wary and difficult to approach. In winter
and spring, ducks are less wary, and most
of them are in their nuptial plumage;
thus, in most species, the sex of each bird
can be distinguished in the field with fa-
cility.
In field tests conducted in 1947 by Uni-
versity of Wisconsin students in game
management and ornithology, the observa-
tions of several students were remarkably
uniform with respect to the sex ratios
they found in flocks numbering up to sev-
eral hundred ducks. It seems safe to as-
sume that field observations conducted
with reasonable care can provide accurate
sex ratios for flocks of ducks present in
late winter and early spring.
Merrill C. Hammond of the U. S. Fish
and Wildlife Service (unpublished data)
found marked variations among waterfowl
sex ratios observed on different sample
areas or at different times, table 7. In a
report, he pointed out the care necessary
in making sex ratio counts in the spring on
the breeding grounds (Hammond 1949:
8-9). He concluded from his observations
that:
These wide differences between certain sam-
ple areas where all [or] very nearly all of
the population was counted indicate that on
any given day the population on a marsh or
water area is not entirely homogeneous with
respects to distribution of the sexes. As Hoch-
baum and others have pointed out, the mated
birds may frequent areas near to nesting habi-
tats, while excess males may associate with a
few females on open sloughs, channels or bays.
Individual flocks and groups, even using sim-
ilar habitats, for one reason: or another may
at times vary greatly.
I~ttinois NaturAL History SurveEY BULLETIN
Vol. 27, Art. Gi
A few field observations on living ducks
were used in the present study to provide
sex ratio data on several duck species.
Examination of Disease Victims.
—At times ducks that are victims of dis-
ease offer waterfowl biologists opportuni-
ties to obtain sex ratio data. Although
available information indicates that botu-
lism and fowl cholera are not more spe-
cific for one sex than the other, it is sug-
gested that sex ratio counts of living
ducks in a disease area be made concur-
rently with counts of the disease victims
for purposes of evaluating the relative
susceptibility of drakes and hens.
Sex ratios among ducks that were vic-
tims of disease in several parts of North
America were considered in the study re-
ported here.
Sex Ratios in Different Age Classes —
It is important to determine sex ratios
of ducks in the different age classes as a
means of discovering at what stage, or
stages, of life disparity in numbers be-
tween the sexes occurs. Are there more
males than females at hatching? During
the first year? During adult life?
For convenience in studying sex ratios
in wild birds, Mayr (1939:156-7) —
grouped sex ratios into three classes based
upon age of birds: (1) primary sex ratio:
the ratio between the sexes at fertiliza-
tion; (2) secondary sex ratio: the ratio
between the sexes at hatching; (3) terti-
ary sex ratio: the ratio between the sexes
during adult life.
It is considered desirable in the present —
study to amend Mayr'’s classification to in-_
clude a sex ratio for juveniles. The re-
vised classification is as follows: s
1. Primary sex ratio: the ratio be- —
tween the sexes at fertilization. B
2. Secondary sex ratio: the ratio be-
tween the sexes at hatching. 4
3. Tertiary sex ratio: the ratio be- re
tween the sexes from the time of hatching —
to adulthood (the beginning of the first
breeding season). te
4. Quaternary sex ratio: the ratio be- —
tween the sexes in adult life. F
Primary Sex Ratios.—There is little
available information on the primary sex
ratio in ducks. Among wood ducks a pri- —
mary sex ratio of 51 males to 49 females —
was determined for 574 fertile eggs by
August, 1961
checking the sex of 85 duck embryos that
died, 419 ducklings that died from para-
typhoid, and 70 survivors. Hochbaum
(1944:51) similarly classified embryonic
and hatched ducklings of the canvasback
and found 344 males and 345 females.
Secondary Sex Ratios.—The second-
ary sex ratios found by Sowls (1955:
164) for four species of ducks are re-
corded in table 8. Statistical analysis of
the data, which are from a study at Delta,
Manitoba, revealed that at hatching the
sex ratios of mallard, pintail, redhead, and
canvasback ducklings did not depart sig-
nificantly from a 50:50 ratio. However,
in each of the four species, males exceeded
females in numbers; when the data for all
four species were combined, there was a
slight but statistically significant pre-
ponderance of males. The findings sug-
gest that the female embryos in these spe-
cies were not as hardy as the embryos of
the males. They are supported by the
Table 8.—Male percentages found at hatch-
ing of artificially incubated eggs of four duck
species at Delta,* Manitoba, and one, the
wood duck, in Illinois.
NumsBer OF DUCKLINGS Per
SPECIES CENT
Male |Female| Total Mate
Wood duck..| 548 564 1,112 | 49.3 NS
Mallard* 394 369 763 | 51.6 NS
Penta. ... . 424 405 SORE Sile INS
Redhead*...| 342 294 636 | 53.8 NS
Canvas-
hacks. . 315 307 622 | 50.6 NS
NS = Not significantly different from 50 per cent at the
0.05 probability level.
*Sowls 1955:164.
Table 9.—Drake percentages in juveniles of
four species of ducks trapped in Manitoba,
1948-1950.
NuMBER OF
SPECIES Ducks pee CENT
TRAPPED EES
SE 1,720 50.2 NS
amin See ccs 351 Sgeso ene 767 43.5*
Blue-winged teal. ... 4,613 47.9*
Redhead........... 757 47.3. NS
BHULESDECIES 5a va es 4,857 47 .9*
NS = Not significantly different from 50 per cent at the
0.05 probability level.
*Significantly lower than 50 per cent at the 0.05 prob-
ability level.
BELLROSE et al.: SEX RatTIos AND AGE RATIOS
403
Table 10.—Drake percentages in juveniles
of nine species of ducks trapped in Saskatch-
ewan, 1947—1950.*
NuMBER OF
Per CENT
SPECIES Ducks
TRAPPED DRaAKEs
Mall ance peepee ree 308 51.6 NS
Gadwallee eon 725 49.5 NS
Baldpateseaneccsce: 672 SO. eis
Pinta eee 273 55.3 NS
Green-winged teal... 27 44.4NS
Blue-winged teal. ... 245 48.6 NS
Shovelenes se. s. one 490 50.6 NS
Canvasbacks.....-- 69 56.5 NS
Lesser scaup........ 87 51.7 NS
ANTES PECTS Henao rye ore 2,896 SAY
NS = Not significantly different from 50 per cent at the
0.05 probability level.
*Unpublished data provided by John J. Lynch, U. S.
Fish and Wildlife Service.
**Significantly greater than 50 per cent at the 0.01
probability level.
Table 11.—Drake percentages in juveniles
of eight species of ducks trapped in Alberta,
1947—1950.*
NuMBER OF
SPECIES aoe pe
RAPPED
IMME. onoeoboenes 209 51.2 NS
Gadwallteennree saeer 26 57.1 NS
Baldpatensee coe see 116 50.9 NS
Pintallereen eee or eee 714 54.3**
Green-winged teal... 18 50.0 NS
Blue-winged teal. ... 164 56.1 NS
Shovelentee-ceee ce: 311 50.5 NS
Wessemscanpaaeeerere 43 60.5 NS
JAE SAGAS Sag cla 5 ea 1,601 Doin)
NS = Not significantly different from 50 per cent at the
0.05 probability level.
*Unpublished data provided by Allen G. Smith, U. S.
Fish and Wildlife Service.
**Significant departure from 50 per cent at the 0.05
probability level.
finding that females made up 52.7 per
cent of 165 dead canvasback embryos re-
ported by Hochbaum (1944:51). In an
Illinois incubation experiment involving
over 1,000 wood duck eggs, slightly more,
but not significantly more, than half of
the ducklings at hatching were females,
table 8.
Tertiary Sex Ratios.—Tertiary sex
ratios were derived from figures of juve-
nile ducks live trapped on the Canadian
breeding grounds, most of them during
July and August, tables 9-11. These
ducks were 1 to 2 months in age. The
juveniles in Manitoba were obtained by
404
drive trapping and bait trapping, while
those in Saskatchewan and Alberta were
obtained by drive trapping only.
Sex ratios of ducklings in three of the
four species trapped in Manitoba, table 9,
showed relatively greater numbers of hens
than of drakes. Statistical analysis
showed that the pintails and blue-winged
Table 12.—Drake percentages in ducks of nine species, juvenile and adult classes, checked
in hunters’ bags in Manitoba, 1946-1949,
JUVENILES ADULTS
5 :
ents Number Per Cent Number Per Cent
Checked Drakes Checked Drakes
MMioallardsx:) Fie. fs vere 6,473 S3.2°* 1,786 49.3 NS
Gath Walll. er enters eae rata ooo 60.25% 137 43.1 NS
Mani nG te. or dh com mdr ons tpearn cous 822 5150 NS 147 5952"
PAM eee Saree Ace i Ney eee 1,145 51.7 NS 293 35.6%"
Green-winged teal................. 257 EWE Ae 58 24.1%
Shovelerme ccc ace eee le octaee 342 50.9 NS 81 32.10%3
Redheade: oie 2h as ot GN oe 1,110 51.0 NS 139 51.8 NS
Canyasback. esc iee io tae sae Ste 2,116 39.8** 232 49.1 NS
Piper sea Os Ate gls ss eh ass 558 47.1 NS 302 60.355
SOME Shae i a ees ae 13,162 50.5 3,175 48.7
NS = Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
Table 13.—Drake percentages in mallards, juvenile and adult classes, checked in hunters’ 4
bags in Illinois, 1939-1955 and 1959.
ILttino1is NATuRAL History SurvEY BULLETIN
Vol. 27, Art. 6
teals of Manitoba had highly significant
excess numbers of hens. Of nine species —
of ducks trapped in Saskatchewan, only
the baldpate (Mareca americana) had a —
significantly higher number of drakes,
table 10. Of eight species of ducklings —
that were trapped in Alberta, table 11, —
seven had sex ratios that did not depart —
JUVENILES ADULTS gp tails Pex Cann
Ape Drakes
fas Number Per Cent Number Per Cent | anp JuvENILE IN Boru
Checked Drakes Checked Drakes PERCENTAGES CLASSES
1 ee 1,337 54.6** 924 GS as + 11.1 59.6
{EA ee 2,093 49.3 NS 1,471 58.5* ree 53.1
eee eee 2,255 45.4** 2,226 68.7** + 23.3 57.0
1942. 980 46.9 NS 829 6/.4°* + 20.5 56.3
1943) G . oe8 939 56.17% 483 67.5** + 11.4 60.0
1944 ee 1,176 48.5 NS 991 68253" + 20.0 57.6
ig elas 898 50.7 NS 1,149 b7-Ot* + 16.3 59.8
1946. 731 P| ae 586 oe A Dees + 19.1 50.5
eT eee 572 49.1 NS 242 67.8* + 18.7 54.5
Na ce fe 924 50.5 NS 291 60.8** + 10.3 53.0
Fee ee 294 = ft bg 303 G7.47F + 10.6 63.5
eo Te ara 351 46.4. NS 230 63..57* + 17.1 53:2
ie ot Ie Paes 517 49.5 NS 302 60.9** + 11.4 Sak
1952. 754 52.7 NS 453 62.0** + 95 56.2
1953. 687 48.6 NS 465 64.5** + 15.9 55.0
1954. 218 51.8 NS 240 10:582* + 19.0 61.8
1955 Ss 478 55:6"? 268 64:57" + 8.9 58.8
1 mearage 63 52.4. NS 184 66.477 + 13.9 62.8
All years....| 15,267 56.4 NS 11,637 65.2** + 14.8 57.0
NS = Not a significant departure from 50 per cent at ihe 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
August, 1961
significantly from 50:50; the pintail had
significantly more drakes.
Among 419 captive wood duck duck-
lings that died from paratyphoid in a
hatchery at Barrington, Illinois, 51.5 per
cent were females. Of 96 young wood
ducks that died from other causes early
in life, 48.8 per cent were females.
Information on the sex ratios of juve-
nile ducks 4 to 9 months old was ob-
BELLROSE et al.: SEX RATIOS AND AGE RATIOS 405
dent in the calculated sex ratios for juve-
niles, tables 13 and 14. Highly significant
deviations from a 50:50 sex ratio in the
juvenile class occurred for the pintail,
green-winged teal, and canvasback. The
most marked deviation in the juvenile
class was for the canvasback; in this
species the drake segment was 39.8 per
cent of 2,116 juvenile birds inspected
early in the fall in Manitoba, table 12,
Table 14.—Drake percentages in ducks of nine species, juvenile and adult classes, checked
in hunters’ bags in Illinois, 1939-1949.
JUVENILES ADULTS DIFFERENCE
BETWEEN
SPECIES ADULT ND
; Number Per Cent Number Per Cent ie
Checked Drakes Checked Drakes "PERCENTAGES
BIC RSI Ge c6 bison crests sees 371 51.7 NS 194 IW (oe + 18.9
Fv Ghy lll Seen 613 Silas 182 53am ae Well
ESIGISR@ero ego Oe eee eee 1,128 51.5 NS 416 Giles + 10.3
incall Gs a 5 pee eee eee 2) Si Soar 1200 (Sa + 4.4
Green-winged teal.......... 399 60noan 160 5/255NS — 3.4
“OS GLSTROTT ie 516 55.4* 110 SINS = 227
Ring-necked duck.......... AG BiSiotels 190 51.0 NS — 2.8
ieamvasback,... 2. s<2s. nec: 352 64.5** 171 (ap ere + 1.6
PRESSEISSCAUID ac aie kis sis oeee « 841 54°2™ 44] 61.0** + 6.8
UY SHIGCT TES Oe eee 7,218 aoe 3,064 61.45* 5S
NS = Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
tained from the inspection of hunters’
bags in Manitoba, Illinois, and other parts
of the Mississippi Flyway.
In Manitoba during early fall, the
sex ratios for a group of juvenile ducks
taken by hunters were nearly balanced,
table 12. Four of the nine species rep-
resented, the mallard, gadwall, green-
winged teal, and canvasback, departed
significantly from balanced sex ratios.
The slight preponderance of males for
the mallard (53.2 per cent males) was
statistically significant because of the very
large sample size. The gadwall and the
green-winged teal had significantly more
males than females, while the canvasback
had significantly more females.
In Illinois, drakes made up 49.3 per
cent of 12,550 juvenile mallards in hunt-
ers’ bags inspected in the period 1939-
1950 and 50.4 per cent of 15,267 in-
spected in the period 1939-1955 and
1959, table 13. Perhaps because of dif-
ferences in migration schedules, consider-
able differences among species were evi-
and 64.5 per cent of 352 juvenile birds
checked later in Illinois, table 14.
When sex ratios were calculated for
juveniles from many areas in the Missis-
sippi Flyway for 1946-1948, tables 15-17,
the effect of seasonal and regional varia-
tions in the data appeared to be mini-
mized. Deviations from a 50:50 sex ratio
among juveniles were significant or highly
significant statistically for only three spe-
cies in 1946 and two species in 1948, ta-
bles 15 and 17. In 1947, deviations from
a 50:50 ratio in juveniles were significant
for one species and highly significant for
four of the species listed, table 16.
The above data, obtained from trap-
ping of ducks in the breeding season and
from checking hunters’ bags during the
fall, indicate that the sex ratios in the
tertiary or juvenile age class are close to
50:50. Local variations that exist appear
to result from different seasonal move-
ments of birds of the two sexes.
Quaternary Sex Ratios.—Popula-
tions of adult ducks normally show much
406
larger drake segments than do those of
juveniles. Exceptions are evident in the
adult ducks shot by hunters in Manitoba,
table 12. The data reveal for adult mal-
lards, gadwalls, pintails, green-winged
teals, shovelers, and canvasbacks in this
area more hens than drakes. For pintails,
green-winged teals, and shovelers, the ex-
cess of hens was highly significant. This
situation came about through the move-
Table 15.—Drake percentages in ducks of 12 species, juvenile and adult classes, checked
in hunters’ bags in the Mississippi Flyway, 1946.
JUVENILES ADULTS DIFFERENCE
— BETWEEN
ECIE T
eee Number Per Cent Number Per Cent pe .
Checked Drakes Checked Drakes PERCENTAGES
ieee ee ee 5,350 47.5** 3,593 57.1** + a5
Black muck ssa ess. «skies 966 47.3 NS 215 6832" + 21.0
EEL GG co oc Rte oo vied oa 474 49.7 NS 249 55.0 NS + 5.3
Bald pate tel Sikes sicher nc rete 462 46.1 NS 119 60.5* + 14.4
Pintatl, cree Sas ener © oc 681 54.9* 426 65.0me + 10.1
Green-winged teal.......... 360 51.6 NS Ry) 52.2NS + 0.6
Blue-winged teal........... 411 46.9 NS 122 Kio — 11.7
Shoveler sae kaso ee assem 380 49.4. NS 125 42.4.NS — 7.0
Redhead ha os ore: 806 52.4 NS 204 55.3 NS + 2.9
Ring-necked duck. ........ 416 51.4.NS 113 5S NS +e
Canvasbaclkss 2: Sos en cee 1,663 45a s 208 44.2 NS — 0.9
Lessetincanp sO as.6 3353 P5504 510 48.6 NS 232 51.7 NS + 3.1
AS DECLES oe ue cas oye 12,479 48.3 5/08 56.4 Sat
I_ttrnors NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 6
ment of many adult drakes from the area
prior to the opening of the hunting sea-
son. Of the species for which records are
available, only baldpates, redheads, and —
lesser scaups showed more drakes than —
hens in hunters’ bags in Manitoba.
Statistical analysis of data obtained
from inspection of adult ducks in hunters’
bags to the south, in Illinois, revealed
that in most years there were significantly
a Seen ee
Sa sated
hee
NS = Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
Table 16.—Drake percentages in ducks of 12 species, juvenile and adult classes, checked —
in hunters’ bags in the Mississippi Flyway, 1947.
JuveNILEs ADULTS DIFFERENCE
BETWEEN q
SPECIES DULT ND
Number Per Cent Number Per Cent ee ee
Checked Drakes Checked Drakes PERCENTAGES
Lh ALE vie oie OG rene aa ae Se 7,094 Bp es 2,604 60.8** + 8.3
BAC GUC Kita rere wee raeren es 1,021 49.9 NS 398 55.0 NS + 5.1
Gadwall ene ee as 647 51.3 NS 208 6352 + 12.2
Baldipates ees see 750 48.4.NS 236 60.6** + 12.2
PANE a Ue omires old aided Sac 1,261 53.2% 437 53.8 NS + 0.6
Green-winged teal.......... 574 B2n2 ss 173 50.9 NS — 11.3
Blue-winged teal........... 1,235 7 AP Gis 360 31.4 NS — 9.7
SHOVELERS eRe ee eee ee 284 50.7 NS 56 39.3 NS — 11.4
Redheads cst cee es 396 52.8 NS 91 SS eee — 17.6
Ring-necked duck.......... 291 46.4. NS 85 48.2 NS + 1.8
Gary asbackn tut Asa eats 562 BD eds 143 6l5> + 22.7
WeSSE6 BCAUDE ts crce sere eats 468 46.4.NS 310 6651 ~ > + 19.7
ALN SPECIES soto Sw NOCR Ce Ne 4 14,583 50.8 NS 5,101 50 6.0
NS = Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
August, 1961
more drakes than hens in the samples, ta-
bles 13 and 14. Records on 9,725 adult
mallards over a period of 12 years, 1939—
1950, revealed an average of 65.7 per
cent drakes, with annual percentages
ranging from 58.5 to 68.7 per cent; rec-
ords on 11,637 adult mallards for a pe-
riod of 18 years, 1939-1955 and 1959, re-
vealed an average of 65.2 per cent drakes,
with annual percentages ranging from 58.5
to 70.8, table 13. The adult class of nine
other species of ducks in hunters’ bags
over an Il-year period, 1939-1949, con-
tained 61.4 per cent drakes; annual per-
BELLROSE et al.: SEX RATIOS AND AGE RaTIOS
407
centages ranged from 70.6 per cent
drakes for the black duck to 51.0 per cent
drakes for the ring-necked duck, table 14.
Statistical analysis of data compiled
from the inspection of adult mallards,
gadwalls, baldpates, pintails, green-
winged teals, shovelers, and redheads in
hunters’ bags in Utah over a period of 6
years, 1943-1944 and 1946-1949, table
18, revealed a highly significant greater
number of drakes than hens for all spe-
cies excepting the redhead.
Data from the Mississippi Flyway for
3 years, 1946-1948, tables 15-17, indi-
Table 17.—Drake percentages in ducks of 11 species, juvenile and adult classes, checked
in hunters’ bags in the Mississippi Flyway, 1948.
JuveENILEs ADULTS DIFFERENCE
BETWEEN
SPECIES ADULT (+) AND
Number Per Cent Number Per Cent JuveniLe (—)
Checked Drakes Checked Drakes PERCENTAGES
Jail nil 9p a5 5 eee eee asics 7,416 SP one 2,556 Som Ome + 5.5
PA CKMGUCK. Secale oie. s atslele wees 871 47.2 NS 378 SO} + 11.8
acliyalll tb aolaig earth eeeiee eae 214 53.7 NS 31 58.0 NS + 4.3
Palle ORS: Ae teed ee ener 1,068 49.5 NS 141 50.3 NS + 0.8
RTE PE Se oe caion0 ta ious. arene TPT 51.8 NS 216 56.5 NS + 4.7
Green-winged teal.......... 493 550" 130 49.2 NS — 6.4
Blue-winged teal........... 255 47.5 NS 63 S0euse — 17.4
Be dNCAC Ra cei oe ess aos 680 46.6 NS 82 51.2 NS + 4.6
Ring-necked duck.......... 336 48.2 NS 66 56.0 NS + 7.8
BRAS DAGKS 2.2. Se cece 410 500.3 520 48.5 NS 66 43.9 NS — 4.6
BRESSEEISCAUID © Se csccciecs.css vious 547 49.2 NS 186 Moke? + 18.5
PHIESDECLES of. Fisve’o)c ovens soo bes. 0.8 13,127 51.2 NS SL O15: iSrileae 6.9
NS=Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
Table 18.—Drake percentages in ducks of seven species, juvenile and adult classes, checked
in hunters’ bags in Utah, 1943, 1944, and 1946-1949.
JUVENILES ADULTS DIFFERENCE
BETWEEN
Apu tT (+)
SPECIES Number | Per Cent | Number | Per Cent AND
Checked Drakes Checked Drakes | JUVENILE (—)
PERCENTAGES
a ere 2,027 | 52.3* 2,350 | 62.3** | + 10.0
erly ll meer sp ree ae ai cicbaras ted ale verasepake 1,679 joe me 1955 (Ws + 14.2
ville (Ne) a canst RO Re aie Rae eee eae Diy) 522s 1,183 6lesee + 9.3
BAe AT Meee y eet oti tare ois ey tuace ard lel «tte ye 4,230 46 .8** 6,499 Bh (Sie + 6.8
Picech-winged teal.................. 2,828 Se Ome 4,183 Tonge + 14.9
| FE ig Se es 2,480 Ey liga 1,674 65.07" + tls9
BEE ICAGIUPE NS cre io timate ane Sie oke aie ees 734 See 214 48.6 NS — 8.7
NE SRGHIOT sR e GOO OE DI SEO one ore 16,330 Se oe 18,058 O2n5nn 9.9
NS=Not a significant departure from 50 per cent at the 0.05 probability level.
*Significant departure from 50 per cent at the 0.05 probability level.
**Significant departure from 50 per cent at the 0.01 probability level.
408
cate that adult drakes consistently, but
not in all cases significantly, outnumbered
adult hens in hunters’ bags for mallards,
black ducks, gadwalls, baldpates, pin-
tails, and lesser scaups. By contrast, the
records show that hens were more nu-
merous than drakes among the blue-
winged teals and shovelers inspected, and
year-to-year variation was evident in sex
ratios among green-winged teals, redheads,
ring-necked ducks, and canvasbacks. Ta-
bles 15-17 indicate the statistical signifi-
cance of the departure of these sex ratios
from balanced sex ratios.
Seasonal Variations in Sex Ratios
Sex ratios for many species of ducks
were found to vary from week to week in
any given area as the composition of the
local population changed with arrival and
departure of flocks containing varying
numbers of drakes and hens. The sea-
sonal changes in sex ratios were ascer-
tained through data obtained from trap-
ping, inspection of hunters’ bags, field ob-
servation, and tallies of victims of disease.
Sex Ratios in Fall and Winter.—
The sex ratios of the most important spe-
cies of ducks taken by hunters during the
fall hunting season in areas from the
breeding grounds to the wintering grounds
are indicated in table 19. Sex ratios taken
in southern Manitoba for the pintail, shov-
eler, and canvasback suggest that large
numbers of drakes make an early depart-
Table 19.—Drake percentages in 12 species of ducks é
Ittinois NATURAL History SuRVEY BULLETIN
Vol. 27, Art. 6
ure from the heavily gunned marshes of
Delta and Netley. This early movement
may be initially either south or north, the
direction depending somewhat upon the
species. Information on the early flights
of drake pintails, some of which arrive at
the Gulf of Mexico in August, indicates
that the initial movement of these birds —
is south. Records of large numbers of —
drake canvasbacks and redheads in north- —
ern Manitoba and Saskatchewan marshes
suggest that these birds probably move
north from their breeding grounds before
they move south.
In most species of ducks for which data
are available, drakes made up a smaller
proportion of the hunters’ kill in Mani-—
toba than in three states to the south,
North Dakota, Illinois, and Tennessee,
Seis
table 19. These data indicate that in most —
species more drakes than hens left Mani-
toba in advance of the hunting season
there. A trend toward an_ increasing
drake predominance from north to south
was evident as far south as Tennessee. In
all but two species for which data are
available, the gadwall and shoveler, the
predominance of drakes was greater in
Tennessee than in IIlinois.
a significantly greater number of hens
than of drakes was evident in two species,
the mallard and the pintail, and approxi-—
mately balanced sex ratios were evident in
four species. In all six species it was ap-
parent that more drakes than hens were
In Louisiana,
ManirTosa, Nortu Dakota, ILLtNo!s,
1946-1949 1949 1939-1950
SPECIES
Number | Per Cent |} Number | Per Cent | Number |} Per Cent
of Ducks| Drakes | of Ducks} Drakes | of Ducks} Drakes
Mallardcce. apes irccets srced erento 8,259 52.4 2) 212 57.5 | 22,008 56.5
BLACK UC sede esc ates Gea ae se eee leet esa: cube eisel or niktaete siralcco) ne et eae
Gad wall: murs veers ce ae rete ee 476 55ae 579 54.1
Bald patever. 4 dems sna aur cians 969 522 146 53.4
PANEL swat fiers, Sars CE eto 1,438 49.0 210 53.0
Green-winged tealifcy .2 ck. «.ssegiaete en: 315 Sed 86 5355
Showeletiy so act Wek ae ee Dee 423 47.3 137 51.0
jaa aro Pe GM PN eae Nt Re EIS i, 5 RS, le UR i A bares Aaa 9 342 5550: |... 2.0005) ee
Ringenecked) huckccy....tcsisicss aysesets crite + cxcyers oval cveae scion tee t atl poral t eae ieterel| eee meas ane
RAVES RGR a civ gee ses ous tise tt aoe 2,348 40.7 281 56.0
j EDITS CCE [oe eg ae RA arn a Ea 860 51.6 136 522
PRY Ghee has a as Go Soils a to op 0 ote widvowws winyns ve bes acy u's Ud oy bs koera, Giolla Kio we Gliese cs alae eanetitan
*Sources of data for the various regions:
Louisiana, Richard Yancey, Louisiana Wild Life and Fisheries Commission (per-
North Carolina Wildlife Resources Commission (personal communication).
mission (personal communication) ;
Barber, Jr.,
Manitoba, Delta Waterfowl Research Station; North Dakota, Hielle
August, 1961
north of Louisiana during a large part of
the hunting season.
For all species of ducks except the
shoveler, the differences in sex ratios
among the various regions were statisti-
cally significant. This conclusion must
be taken with some reservations because
the span of years involved was not the
same for each of the various areas. Some
of the observed differences could be due
to time as well as geographic differences.
Among adult mallards bagged in IIli-
nois, 1939-1955, there was a steady in-
crease in the drake segment of the fall
population through the third week in No-
vember, fig. 3. The ratio between the
sexes then tended to stabilize for a period,
followed by an increase in the drake seg-
ment in the wintering population, usu-
ally present in Illinois after the first week
in December. In Utah, sex ratios of adult
mallards bagged were relatively stable
throughout the autumns of several years
in which bag checks were recorded, fig. 4.
Adult pintails bagged in Illinois and
those bagged in Utah showed little varia-
tion in sex ratios during the fall. Adult
green-winged teals and shovelers bagged
in Utah showed an increase in the drake
segment as the season progressed, fig. 4.
In only a few species do there appear
to be differences in seasonal movement be-
tween drakes and hens of the juvenile
class. In Manitoba, the canvasback had
an unusually large number of hens among
BELLROSE ef al.: SEX RATIOS AND AGE RATIOS
409
the juveniles bagged, table 12; in Illinois,
on the other hand, this species had an
unusually large number of drakes among
the juveniles bagged, table 14. The drake
segment of the juvenile mallard popula-
tion bagged in Illinois increased through
the second week of November and then
tended to stabilize, fig. 3.
Sex ratios of ducks in the marshes ad-
jacent to Great Salt Lake, Utah, have
been quite variable from week to week
and year to year in autumn.
The week-to-week variation in sex ra-
tios among ducks of these marshes is un-
derstandable in view of the fact that in
early summer the areas are the breeding
grounds for ducks of many species, later
a major molting area for transient pin-
tails and green-winged teals, and still
later one of the important migration areas
for ducks in the Pacific Flyway. Chrono-
logical differences in movement of vari-
ous groups of ducks—those that breed in
the area, early migrants that wing-molt
in the area, and large numbers of fall
migrants that rest there—have resulted in
ever-changing sex ratios.
Year-to-year variation in sex ratios is
shown in data from the Bear River Mi-
gratory Bird Refuge at the north end of
Great Salt Lake (Van Den Akker & Wil-
son 1951:379). In that area hens out-
numbered drakes in 8 of 13 species in the
period 1936-1940. However, during the
hunting seasons in later years, 1943-1949,
checked in hunters’ bags in seven regions in North America.*
TENNESSEE, LoulIsIANna, Texas Coast, NortH Carona, | ProBasiLity
1951-1952 1951 1947-1951 1948-1952 THAT
DIFFERENCES
AMONG AREAS
Number | Per Cent | Number | Per Cent | Number | Per Cent | Number | Per Cent Are DUE
of Ducks! Drakes | of Ducks| Drakes | of Ducks| Drakes | of Ducks} Drakes to CHANCE
14,068 58.1 3,471 45.5 2,683 44.1 73 50.7 <0.0005
127 SLOSS yl ienesteee ae et | [Eerste ne ea aoe SN a AR RI 109 ie Seal HI tee ee ee en
2,007 HITS Sa ipaley cag ON [Aiea amen 696 43.7 228 57.9 <0.0005
317 GA Sil aeeu et tie tReet 620 Red 644 54.2 <0.02>0.01
1,084 67.1 1,204 45.9 2,688 69.5 271 70.5 <0.0005
688 63.4 eat 49.1 1,160 54.7 96 S120 <0.0005
174 SIG tan Be enal eres ll sie deus tectee 963 48.8 201 SN7, <0.20>0.10
107 (GSA cee ct ills ernie 1,782 rE re | Meee ot (EE aes Cede <0.0005
3,080 69.2 Soil CLS? ase | a uns ae na aia 104 61.5 <0.0005
544 69.1 78 51.4 227 48.0 349 41.8 <0.0005
516 66.1 752 49.5 456 62.9 48 40.0 <0.0005
282 Gor Sime nee eee lp ene Es Reva ie tener e 392 SOG et |e oes dec
(1950:14); Illinois, authors of present paper; Tennessee, Charles K. Rawls, Jr., Tennessee Game and Fish Com-
sonal communication); Texas Coast,
Singleton (1953:57);
North Carolina, T. Stuart Critcher and Yates M.
410
at Ogden Bay, midway on the east side
of Great Salt Lake, hens outnumbered
drakes in only a few instances: in pin-
tails 2 years and in redheads 1 year, table
20. When the statistical significance of
the differences between the data for these
years was investigated, the year-to-year
fluctuations in sex ratios were found to be
100
75
PER GENT
PER CENT
0
I5-22 23-31
OCTOBER
|-7 8-15
Intinois NaturAL History Survey BULLETIN
Juvenile Hens
al
‘Adult Hens
NOVEMBER
highly significant for all species except
the baldpate and the shoveler. Popula-
tions that were top-heavy with drakes
were observed in this same area before the
hunting seasons of 1944 and 1950. Ducks
that were victims of botulism in the Og-
den Bay area showed that adult drakes
were much abundant than adult
more
Ys
\-7 8-15
DECEMBER
16-23 24-30
Vol. 27, Art. 6
Fig. 3.—Drake-hen composition of the adult and juvenile segments of the autumn flight of
mallards in Illinois, as indicated by data from checks of hunters’ bags, in the autumns of 1939
1955. The drake segment of the juvenile mallard population increased through the second 2
week in November and then became relatively stable.
411
Sex Ratios AND AGE RaTIOos
BELLROSE ef al.:
August, 1961
hens in late summer and early fall of these
years, tables 21 and 22. At the Bear River
Migratory Bird Refuge during the sum-
were abnormally abundant among botu-
mer of 1952, drakes of several species
lism victims, table 23.
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412
early spring have revealed differences in
the sequence of the northward migration
of drakes and hens of the same species.
The sequence in the migration of drakes
and hens varies with the region, table 24.
In the Illinois River valley, tallies of
drakes and hens in late winter and spring
were compiled for the years 1940-1946,
fig. 5.
A preponderance of drakes was most
pronounced for the mallard, pintail, can-
vasback, and ring-necked duck late in
February. In the redhead and the lesser
scaup, drakes predominated to the great-
est extent in the second half of March;
in the baldpate, in the second half of
April.
Farther north in the Mississippi Fly-
way, in Minnesota, Erickson (1943:27)
observed changes in the drake and hen seg-
ments of the populations during the spring
migration periods of 1938-1940. Among
Table 21.—Drake percentages in seven species of ducks, juvenile and adult classes, afflicted :
with botulism at Ogden Bay Bird Refuge, Utah, August 1 to September 29, 1944.*
SPECIES
Number
ME ee ee oe ae 77
Ganwall eee rte a. ate ae 7
Haldia... Aoi ss eas ce ons 29
Pini tail Chto sess trawler Oe one 502
Greem-wintted: teals suse. Sg sie sine es 292
Crnnation teal oo.6.2c oes neta 17
Shaveleren eect anki eens eee 89
AUD SI CELE Sees tae bes oa teshee ice 1,013
*Unpublished data from Noland F. Nelson, Utah Fish and Game Department.
Table 22.Drake percentages in six species of ducks, juvenile and adult classes, afflicted —
with botulism at Ogden Bay Bird Refuge, Utah, late summer, 1950.*
SPECIES
Number
Mallakd he Ae Let N Oc S Sicdn 4
Gadwalliesse ois tree nics cee ee 3
Pia dO 2 oo dincds'y, cia, ats mips wp Bin 63
Puritans 3 eee skins Gee ae 299
Green-winged teal iid. 2 6 eles. 2 a 13
lig eetleies oie rashes siuioee Wccate ators Bin ae 34
8 ee NER PPO A a Ca 416
*Unpublished data from Noland F. Nelson, Utah Fish and Game Department.
I~urinois NaturAL History SurvEY BULLETIN
ADULTS
JuvENILES
Per Cent Per Cent
Drakes Number Drakes
71.43 43 48.84
14.29 10 40.00
86.21 9 44.44
60.56 163 45.40
80.14 118 62.71
58.82 Sp) 65.63
69.66 71 71.83
68 .21 446 55.83
ADULTS JUVENILES
Per Cent Number Per Cent
Drakes Drakes
50.00 12 83.33
66.66 rs 14.29
52.38 71 45.07
70.57 91 62.89
38.46 a 33.38
50.00 25 48.00
64.90 215 53.85
Vol. 27, Art. 6
blue-winged teals, in 2 of the 3 years, the
relative number of drakes was consider-
ably greater in the first than in the second ~
of the two parts into which Erickson di-
vided the migration period. Among shoy- |
elers, in each of the 3 years, the relative
number of drakes was greater in the sec-
ond part than in the first part of the mi- —
gration period. Among lesser scaups,
drakes predominated throughout the mi- —
gration period in each year, but to a lesser _
extent in the second part than in the first. —
Among ring-necked ducks, the sex ratios —
varied little between the two parts of each —
migration period or among the 3 years; —
the average male to female ratio for the —
3 years was 1.36:1 in the first part and —
1.43:1 in the second part of the migra- —
tion period. 4
Near Minneapolis, in the spring of —
1950, Nelson (1950:119) observed male
to female ratios of approximately 1.3:1 —
August,
Table 23.—Drake percentages in four species of ducks, juvenile and adult classes, afflicted with botulism at the Bear River Migratory Bird
Refuge, Utah, summer, 1952.*
SHOVELER MALLARD
GREEN-WINGED TEAL
PINTAIL
Adult Juvenile
Juvenile
BELLROSE et al.: SEX RaTIos AND AGE RATIOS
norm CO
coomwonm else)
m™~wowoo my
NoOwnro mn
SNM mM =e
IMAHH ow
Nocro So
m~ovwr my
NON — Noli se)
Aw SY =O
“moO On
Ci a) Om
“MOr~ ™~™o
mw tH wow
met (ej Ss
July
4th week...
Dn
+ U 5
5 S-4 aS anne.
“NC coo +
= Ao “mh Ww
: | eal |
> 5
3 ' .
mea} § w +079 00 Nol ws
Oo “wom oon
5a - nN ere
g =
~ . \O
S54 epee oat
v 18) “COO MO
eS Z
x ' 3
Ex “904 wt
53 0 “~E HD
Aa . roo) A
n
a2 \o mewon tH
ZIeOk SSSR HS
re
vu
>
ej U psu AMD Neflea
me) Ex co toro ac
53 ¥ ANNA aloe)
7 z
—
Ist week ..
2nd week...
September
Type C, on the Bear River Migratory Bird Refuge During Sum-
Afflicted by Clostridium botulinum,
“Sex and Age Ratio of Waterfowl
1952” by Jack P. Allen, Utah Cooperative Wildlife Research Unit, Logan.
*Calculated from data in a report,
mer,
413
among river ducks and approximately
2.0:1 among diving ducks.
In northwestern Iowa, Glover (1951:
+86-91) recorded sex ratios for migrat-
ing waterfowl during spring in 1948 and
1949. The preponderance of drakes he
observed among early arrivals of mallards
and blue-winged teals declined somewhat,
and thereafter the sex ratios of these spe-
cies remained fairly constant. The sex
ratios of gadwalls varied little during the
spring. Drakes predominated in baldpate
populations throughout the northward mi-
gration period, to the greatest extent to-
ward the end of the period. The drake seg-
ment was greater than the hen segment
among pintails and shovelers throughout
the spring migration and showed peaks in
late March, the middle of April, and early
May. The drake segment among lesser
scaups also exceeded the hen segment
throughout the spring migration; a
marked peak in drake abundance was
reached during mid-April. Drakes pre-
dominated markedly among the first red-
head arrivals, and again among the late
departures. Among ring-necked ducks, a
high peak in drake predominance occurred
the first half of April; a near balance in
sex ratios prevailed during the remainder
of the spring migration season.
In the lower Souris National Wildlife
Refuge, North Dakota, Merrill C. Ham-
mond found marked variations in water-
fowl sex ratios taken at different times
during the spring, table 7. Pintail, lesser
scaup, and redhead sex ratios were more
heavily unbalanced in favor of drakes late
in the spring than early. Changes in the
sex ratios of pintails were significant at
the 95 per cent level (X?=20.9, 3 d.f.).
The changes were not significant at the
95 per cent level for the lesser scaup
(X?=3.1, 2 d.f.) or the redhead (X?=
(dee).
In the Pacific Flyway, in western
Washington, Beer (1945:119) calculated
sex ratios of ducks from September
through April. In December, mallard sex
ratios were evenly balanced; in January,
they were slightly in favor of drakes and,
in February and March, slightly in favor
of hens. The drake segment in the pintail
population progressively declined from
November through March. The sex ratio
for lesser scaups was balanced in January,
414 ILtrnors NaturAL History SuRvEY BULLETIN Vol. 27, Art. 6
Table 24.—Drake percentages in 10 species of ducks observed
NortH
Catt- Wasu- ;
OREGON, Dakota, Manirosa,
1948-1921 | 1946-1948 | 1943 1944 | 1939-1942, | 1939-1945
3 1947-1950
SPECIES
bh n Vv
= 3] 83
EWP ox
53 6A}500
Z. Ay
Malate sae ibe eee ean 1,039] 55.4 | 5,589) 55.9 | 1,652) 50.7 | 3,202) 51.7 | 2,423) 50.6m
Balin ate. oo isc ce aks 432] 45.8 30| 53.3 | 4,999} 53.3 911) 57.20) 540 el
Petal vc aes et eaaiceas cals ace ly ane 4,561} 57.4 622} 52.2 |10,173) 52.7 | 3,250) 51.99
Loy These Lciegolt in eco: | ape REA POM Udi, (PPS Bagi ie IN (ap bo 5,554) 55.5) les. nae
eli ri de sae an eS ele ok Rep ee 362) 6926") 2,823) 5974 101) 53.5. | 2,000] SS) 7g nee 3
Reed ear 28d Oa. aciard ts pihacanaaece aa ane Uiheaea terre ae et ke cua mi Rote 1,805} 54.8 | 926 | 58.1%
Ring-necked duck.......... (eNTAING Pao) OSS] Pap ess Dae alin aN Paar eal lbrcre he 63) (57.12 ee =
Ganvasback Sie erie SHAG) WeeeGhes Oot lie euansia jamie oak 316} 67.7 826] 62.6 | 2,916) 65.4 ~
[sessen/scavipive 2 faa fos sats BS AL st Sirf | Pes PAA De 911} 59.8 | 7,401) 64.0 |10,387| 66.8
Bechet Che. dicar Soy ee Ny ie be eR eR eee «cock Rah sites rete 1,886) 64.7 |... ..)eeeaee %
*Sources of data for the various regions: California and Oregon, Evenden (1952:393); Washington, Beer _
(1946:409); Minnesota, Erickson (1943:27); Illinois River Valley, authors of present paper (unpublished); Mis-—
(1951:487, 490) for mallard, baldpate, pintail, blue-winged teal, and shoveler, and Glover (1951:489) and Low —
ford (1954:78).
Lesser Scaup
90 x
\
2
\ Ring— Necked Duck
=
ae aS aX
ee a
a \
80 \ \
uw
=x
.- 4
e
é -
—
#20
WwW
oO
4
Ww
a
60 eee a
Baldpate
50
2! 8 16 24 8 16 23
FEBRUARY MARCH APRIL
Fig. 5.—Periodic changes in the drake percentage of the flight of each of seven species of
ducks during spring migration in the Illinois River valley, 1940-1946. Data were obtained from
counts of living birds. A preponderance of drakes was most pronounced for the mallard, pin
tail, canvasback, and ring-necked duck early in the migration period. For the lesser scaup, é
preponderance of drakes was most pronounced in the second half of March. :
August, 1961 BELLROSE et al.: SEX Ratios AND AGE Ratios 415
mostly during the spring months in 10 regions of North America.*
Mississippi
ee ee “| alg trom) ames | paoniewes
1938-1940 VaLLey, Iu.wors, 1949 1949-1952 AREAS THAT
1940-1947 | 1948-1951 DIFFERENCES
AMONG
hi n O| u n G| yu n Gl re PA ae an rs a ARE
2 S| gals S| gels S| eslS | ee] &) ge] Per Cent me
3 oS. 2 3) ein = 3) fea, = Oss |ieieee oO & Deak CHANCE
53 0AI5OA]5 oA) 500A] Ss SAl5OA|s SA)/sO0A|s sAly00 AGUAS
Zz A, Zz Ay Z AY Z Ay Zz Wf
256} 50.4 |11,125| 54.8 800) 53.2 |17,085) 52.7 |10,431} 50.3 52.6 <0.001
126) 54.8 | 1,238) 61.6 fis) S8iokh |) WSs} 5G) || WE 752) 5525 54.6 <0.001
322) 53.7 | 4,218) 63.2 | 2,000} 77.4 | 4,370} 71.8 | 5,178) 54.6 59.4 <0.001
447| 59.7 POTN GSA al Ee cee | Perri 3,782) 59.6 | 1,644) 56.8 59.3 <0.001
253) 56.5 Poe skeen 1 eee ae Creceiok 2,377] 66.6 892) 63.5 60.1 <0.001
PO MOON 75880] 60.1 I... cn alls nee «< 45385| 580) | a2 75| OO, 60.2 <0.001
OOM Nee OSL. 1304 cae 2 alle sctee GoM (7/0) |) O59) 4252 61.4 <0.001
147| 64.0 | 6,164) 79.4 | 3,678) 75.2 | 2,049) 65.0 | 2,016) 65.3 66.4 <0.001
3,114) 72.0 |19,188) 86.9 17,873} 82.1 |11,434) 69.1 |11,885| 57.0 69.5 <0.001
80] 48.8 AGO eA le ste sual ates 19976) 65..8 438) 53.4 62.0 <0.001
(1945:119); North Dakota, M. C. Hammond, U. S. Fish and Wildlife Service (unpublished); Manitoba, Hochbaum
sissippi River Valley, Illinois, George Arthur,
but by April there were almost two drakes
to every hen. In eastern Washington, Yo-
com (1949:226) found among mallards
relatively more drakes during December
than during other months of his study;
the number of hens increased proportion-
ally in January, and in February there
were more hens than drakes.
In the first + months of 1948, sex ra-
tios of mallards in the Texas Panhandle
were obtained from counts of ducks pre-
sumed to be victims of fowl cholera, table
25. These data revealed statistically sig-
nificant (X?=16.5, 6 d.f.) chronological
differences in sex ratios at the 95 per cent
level. In winter the mallard drakes and
Illinois Department of Conservation (unpublished) ;
(1941:144) combined for redhead, ring-necked duck, canvasback, lesser scaup, and ruddy duck;
Glover
Mum-
Iowa,
Indiana,
hens were about equal in number. The
drake segment increased during the spring
migration, and it was especially large at
the end of the migration period. Inas-
much as hens were found by Singleton
(1953:57) to predominate in mallard
populations on the Texas coast during
the hunting season, table 19, it is assumed
that the progressive increase in the drake
segment in the Panhandle resulted from
the lingering of unmated drakes on the
wintering grounds. Large numbers of
mallards are paired during the fall and
winter; probably some of the unmated
drakes were juveniles that had lagged in
testicular development while others were
Table 25.—Drake percentages in mallards and pintails found dead, presumably from fowl
cholera, on the Muleshoe National Wildlife Refuge, Texas, 1948.
MALLARDS PINTAILS
PERIOD
Per Cent Per Cent
Number Wakes Number Drakes
Memes Heb: (6)... dec dacksGeewe sas | 21 50.2 330 64.8
eran) Oe cet ce eee oe ds Senate 436 54.6 98 60.2
—veloy, DIES Ege i ty aa eee 3,014 56.0 769 5720
ay ela Tg ae ae ae eet 831 5/58) 236 54.2
MMe ee ceeme oot al sisiers, fa cGue oa 643 56.3 328 55.8
2 Sl TESA Sneed er 162 56.8 16 43.0
Gall RSG Get ae teen ee eee einer 47 63.8 8 50.0
TRA A DTU OD > sscaiccte so sie eis coe’ 6,345 55.0 1,785 57.9
416
adults in which the testes had not reached
recrudescence.
Among pintails presumed to have died
from fowl cholera in Texas in the first 4
months of 1948, the sex ratio trend was
the opposite of the trend among mallards,
table 25, from a population predominantly
Ittrnors NArurRAL History SuRVEY BULLETIN
Vol. 27, Art. 6
in Mexico, than does the mallard popu-
lation.
Sex Ratios in the Breeding Season. —
—Seasonal changes in sex ratios of ducks —
observed on the Manitoba breeding —
grounds in 1947 and 1949 are shown for
various species in tables 26 and 27. In
drakes at the start of the period toward a_ April, the first flights arriving on the .
balanced population at the end. The breeding grounds showed, with minor ex- —
change in pintail sex ratios was not signif- ceptions, a closer approach to a balance —
icant at the 95 per cent level (X°=10.4, between the sexes than did subsequent :
6 d.f.). Drakes were found to predom- populations on the breeding grounds, fig. —
inate in the pintail population along the
Texas coast during the hunting season,
table 19. It may be concluded that the
pintail drakes tend to winter farther north
than the hens but that most of the pintail
population winters farther to the south,
ee
6. Somewhere between the mid-flyway
areas and the breeding areas of southern —
Manitoba, late migration waves predom- :
inating in hens appeared to overtake early —
migration waves predominating in drakes. 3
A tendency toward balanced sex ratios
Table 26.—Drake percentages in seven species of ducks observed in four periods of the
spring months along study transects on the Manitoba breeding grounds, 1947.*
Apri 15-30 May 1-15 May 16-31 June 1-15
SPECIES Number Per Number Per Number Per Number Per
of Cent of Cent of Cent of Cent
Ducks Drakes Ducks Drakes Ducks Drakes Ducks Drakes
Mallard....... 162 52.5 341 67.5 150 77.5 308 78.0
a rahy gl iene ge eames. al HSER Pha ie 72 54.0 45 55.5 89 56.0
Pinta: 2 62 140 55.5 248 75.0 139 73.5 197 78.0
Blue-winged
fealuie suet. 41 62.0 297 58.0 153 59.0 283 71.0
Shovelete te csc lec st calteeeeaet 240 55.5 60 58.0 135 69.5
Canvasback.... 164 55.0 139 65.5 125 FES) 139 83.5
Lesser scaup.... 48 67.0 616 66.5 118 61.0 211 65.5
*Data supplied by Arthur S. Hawkins, an author of this paper.
Table 27.—Drake percentages in 10 species of ducks observed in four periods in the Mina
nedosa pothole district of Manitoba, 1949.* ;
ApriL 21-25 ApriL 29-May 7 May 14-JuNnE 6 Jury 5-26
SPECIES Number Per Number Per Number Per Number Per
of Cent of Cent of Cent of Cent
Ducks Drakes Ducks Drakes Ducks Drakes Ducks Drakes
Mallard....... 829 53.9 fee. 67.9 975 73.6 194
Gadwalliae en stle os ceeelnd eee 75 54.7 220 57 33
Baldpate........ 73 521 209 53.6 363 54.8 61
Pinta: Gases 213 59.2 235 74.0 274 76.6 67
Green-winged
tealsjsetesetcn 52 53.8 198 53.5 164 63.4 40
Blue-winged
teal ass tic NG ei Suissa 547 53.9 925 57.4 350
Shoveler....... 32 50.0 124 58.1 201 Se, 51
Redhead....... 64 51.6 114 52.6 231 55.4 34
Canvasback.... 190 54.2 285 56.8 334 61.1 135
Lesser scaup ... 163 65.0 442 60.2 459 58.8 166
*Unpublished data supplied by W. H. Kiel, University of Wisconsin.
August, 1961
among early arrivals on the breeding
grounds evidently is observed in late
March and early April on the Oka State
Sanctuary in Russia, where the first mal-
lards to arrive are paired (Teplov & Kar-
tashev 1958:160).
The upward swing in the relative num-
bers of drakes among the mallards and
pintails seen by observers in early May,
tables 26 and 27, soon after arrival of the
ducks on the breeding areas of Manitoba,
may be indicative of the rate at which hens
leave their mates to incubate.
By mid-July the relative number of
80
70
60
—
——
SO Baldpate
40
PER CENT DRAKES
30
20
APRIL 21-25
BELLROSE et al.: SEx RatTIos AND AGE RaTIos
APRIL 29-—MAY 7
417
drakes among ducks seen on potholes in
southwestern Manitoba, table 27 and fig.
6, had noticeably decreased in all species
—less in the lesser scaup and the blue-
winged teal than in the other species. At
this time, the drakes were evidently leav-
ing the breeding areas for the lakes or
marshes where they would enter the
eclipse molt.
A similar sequence in sex ratios was
found in 1949 by I. G. Bue, then at the
University of Minnesota, in ducks seen
on stock ponds in western South Dakota,
fig. 7. Between the first week of May
JULY 5-26
MAY |4 —JUNE 6
Fig. 6.—Periodic changes in the drake percentage in each of six species of ducks on a
breeding grounds area near Minnedosa, Manitoba, April 21—July 26, 1949. Data were obtained
from counts of living birds.
418
and the last, during the time pintail hens
were leaving their mates to nest, the num-
ber of drakes increased from 57 to 81 per
cent of the pintails observed. An abrupt
decrease in the relative number of pintail
drakes took place in the first half of June
when many of them were departing for
areas in which to molt. Mallard drakes
were about 2 weeks later than pintails in
their departure to molt, and blue-winged
teal drakes were about 2 weeks later than
the mallard drakes.
Sex ratios of ducks seen during the nest-
80
75
70
65
PER CENT DRAKES
60
55
50
8 IS 2i | 9
Fig. 7.—Periodic changes in the drake percentage in each of three species of ducks on stock
ponds in western South Dakota, April 8—July 17, 1949. Data were obtained from counts of living
birds and were provided by I. G. Bue, Commissioner, North Dakota Game and Fish Depart
ment, Bismarck, while at the University of Minnesota.
ILtinois NArurRAL History Survey BULLETIN
6.) 22 29.75 12
MAY
Vol. 27, Art. 6
ing period may provide useful informa-—
tion on the destruction of duck nests.
When their nests are destroyed, hens re-—
turn to their waiting sites, where they
can be seen by observers; this behavior
results in an apparent increase in the rela-
tive number of hens in the populations. —
Lynch (1948:26) presented evidence to
show increases in the relative numbers of —
paired mallards and pintails seen on a
study area in southern Saskatchewan late ©
in May, 1947. These increases may have
been attributable to heavy nest losses re-—
=
August, 1961
sulting from the plowing of wheat stubble
in which hens were nesting.
Regional Variations in Sex Ratios
Sex ratios in ducks were found to vary
with migration routes and wintering
grounds, fig. 8.
The relative number of drakes among
mallards reported bagged in the late
80
70
60
50
ram o,
<x
PER CENT DRAKES
Xx
Se
40
‘
oe
So
KS
o,
es
res
SRK
"es
renee
SRK
30
20
OHIO
BELLROSE et al.: SEX RATIOS AND AGE RarTIOos
ILLINOIS
WISCONSIN
419
per cent hens) than drakes among 13,959
mallards trapped and banded in a period
of about 12 years. More hens than drakes
were reported among a few mallards in
hunters’ bags in eastern Wisconsin by
Hopkins (1947:28), who also reported
more hens than drakes among mallards
that were trapped and banded in the area.
The report by Hopkins is interpreted to
Adult Class
Juvenile Class
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Fig. 8.—Drake percentage in juvenile and in adult mallards checked in hunters’ bags in each
of six states and the province of Manitoba, 1946-1948. More drakes than hens were checked in
each state or province except Wisconsin.
1940’s in Ohio was considerably more
than the relative number among mallards
reported bagged in Nebraska, fig. 8; the
two areas are in approximately the same
latitude but in different flyways. In each
area more drakes than hens were bagged.
The much greater kills among juvenile
drakes than among adult drakes is unex-
plained.
A preponderance of hens was reported
for an area in British Columbia by Munro
(1943:247), who found more hens (54.3
mean that more hens than drakes of the
mallard were in the area during the fall
of 1946, the period covered by the report.
Drakes and hens apparently occur in
various ratios in various areas of their
wintering grounds. In Louisiana, table 19,
inspection of hunters’ bags showed that
not only was the relative number of
drakes low for all species but that hunt-
ers killed more hens than drakes in the
mallard, pintail, green-winged teal, and
lesser scaup. To the west, on the coast of
420
Texas, hunters bagged more hens than
drakes in the mallard, gadwall, shoveler,
redhead, and canvasback. On the Texas
coast, the relative number of drakes was
unusually high only in the pintail and
lesser scaup, species in which a large part
of the population winters in Mexico.
In every duck species for which com-
parable figures were collected, the drake
segment was larger in Tennessee, an area
representing the northern part of the win-
tering grounds in the Mississippi Flyway,
than in Louisiana, at the southern ex-
tremity of the flyway, table 19. Sex ra-
tios obtained for the mallard, baldpate,
and green-winged teal from inspection of
ducks found dead in the Texas Panhan-
dle, table 31, favored drakes to a greater
extent than did sex ratios for these same
species obtained from inspection of hunt-
ers’ bags on the Texas coast, table 19.
Drakes predominated in pintails about
equally in these two Texas areas. In
Texas coast mallards cited by Singleton
(1953:57), the sex ratio for adults was
almost evenly balanced; however, among
juveniles, there were substantially more
hens than drakes. Relatively greater num-
bers of hens than of drakes may occur in
waterfowl populations to the south, in
Mexico.
Although drakes greatly predominated
among lesser scaups taken on the Texas
coast, table 19, hens predominated among
redheads and canvasbacks. Because only
small numbers of redheads and canvas-
backs are known to winter north of the
Texas coast in the Central Flyway and
because of the known preponderance of
drakes in these species, it is assumed that
large numbers of drakes of these species
winter farther south on the Gulf Coast,
in Mexico.
In the Currituck Sound area of North
Carolina, where many species of ducks
winter, bag checks in 1948-1952 showed
the number of drakes to be relatively low
for the green-winged teal, shoveler, can-
vasback, lesser scaup, and ruddy duck
(Oxyura jamaicensis), table 19. Because
large numbers of these ducks winter to
the north of Currituck Sound, it is be-
lieved that the drakes of these species may
be more numerous in those areas. The
relatively large numbers of drakes among
bagged pintails and gadwalls at Curri-
Ittrnors NATURAL History SuRVEY BULLETIN
Vol. 27, Art. ;
tuck Sound suggest that populations off
these species to the south have proportion- —
ally fewer drakes.
During the spring migration, the re-
gional variations in the sex ratios of ducks ‘
are even more pronounced than they are
during the fall migration. Table 24 shows —
the variations in sex ratios among several
species of ducks in 10 regions of North —
America. The mallard and the _ blue-
winged teal showed less regional variation
in sex ratios than the other species. In
no region did the drake percentage for the -
mallard deviate more than 3.3 percentage
points from the average for all regions
represented. The comparable figure for
the blue-winged teal was 5.3. Drakes
formed more than 60 per cent of the pop-
ulation of eight species in Illinois, six in
Iowa, and three each in California, Nori
Dakota, and Indiana, table 24. .
Illinois appears to be on a major flyway
route for male ducks during the spring.
In most species migrating through Illi-
nois, the number of drakes in the spring, —
table 24, is relatively larger than the num-—
ber of drakes in the fall, table 14. There
is evidence that adult drakes of certain
species, especially the divers, make longer
flights during the fall migration than do
the hens and the juveniles of both sexes.
The probability that, in the fall, adult
drakes of these species pass over Illinois, —
or move more quickly through the state —
than do the hens and juveniles, suggests ©
one explanation for the pronounced dif-
ferences between fall and spring sex ratios.
Sex ratios of ducks show less deviation —
from balanced sex ratios in northern —
areas than in other areas of the Mississipp
Flyway in spring, table 24. In Minne-
sota, North Dakota, and Manitoba, sex
ratio data were collected primarily on ex-
tensive lakes and marshes frequented by
large numbers of transient ducks. Be-
cause of the location of the area, the size
of the samples, and the period of years
over which data were collected, the sex
ratios from North Dakota appear to rep-—
resent the various species in spring better
than the sex ratios from other areas. ;
Mortality Factors Affecting
Sex Ratios
op Decche
As an approach to an evaluation of fae-
tors that contribute to deviations from
August, 1961
BELLROSE ef¢ al.: SEx RATIOS AND AGE Ratios
421
Table 28.—Drake percentage in each of 10 species of ducks banded by Ducks Unlimited*
in the prairie provinces of Canada, 1939-1950, and the drake percentage in the year-of-banding
recoveries. The difference between these two percentages for each species is a measure of
hunter selectivity for that species, + for drakes, — for hens.*
Ducks BanpeD YEAR-OF-BANDING Prosa-
RECOVERIES Dirrer- BILITY THAT
ENCE
SPECIES BETWEEN a age
Renae Num- Per Nia Num- Per PEr- IFFERENCE
Is Dur
fs ber Cent ae ber Cent | cENTAGES
Drakes | Drakes Drakes | Drakes TO CHANCE
Mallard... 5... 21,021 | 10,405 | 49.5 2,131 iNsalesyit 53.1 + 3.6 |<0.001
Gadwall oi. ..5. 1355 602 | 44.4 134 68 | 50.8 + 6.4 |<0.20>0.10
Baldpate........ 1,940 991 Sie 168 shay || ube sp Weil) SS0),28)
GAN cs ce ees MATS | 132697 4) 3980 582 263 | 45.2 + 6.2 |<0.01>0.005
Green-winged
Realltsralcns sas leys.« 15973 1,031 By 58) 70 35) | 5020 = 23) |< Oe 0 0560
Blue-winged teal | 12,343 | 6,171 50.0 341 168 | 49.3 — 057 | <05805-08 75
Shoveler........ 686 346 50.4 41 29 TOE 7 + 20.3 |<0.01>0.005
Redhead........ 2,042 | 1,100} 53.9 266 148 | 55.6 aie ld 060-0750
@anvasback..... 511 245 | 47.9 60 a AS 0 — 2.9) |'<0-60>0:.50
Messer scaup...-| 5,134) 2,615 | 50.9 320 159 | 49.7 — 1.2 |<0.70>0.60
*Data calculated from Cartwright & Law (1952:10-2).
balanced sex ratios in ducks, it is desira-
ble to examine the influence of each of the
several factors responsible for mortality
in these birds. The principal agents that
contribute to mortality in ducks are (1)
hunters, (2) disease, (3) predators, (4)
agricultural operations, and (5) natural
stress.
We seek to answer this question: Are
hunters, disease, predators, agricultural
operations, and natural stress responsible
for greater loss in the ducks of one sex
than in those of the other?
Hunting and Sex Ratios.—The data
on hunter kill of ducks banded in Can-
ada, 1939-1950, and recovered in the
year of banding, table 28, reflect the coun-
try-wide influence of hunting on the
drake-hen ratios because the banding was
done on the breeding grounds during late
summer and early fall at or before the be-
ginning of the hunting season and the
southward migration period.
Statistical treatment of the data showed
that hunters took a highly significant
greater number of drakes than of hens in
the mallard, gadwall, pintail, and shov-
eler. Hunters took fewer, but not sig-
nificantly fewer, drakes than hens in the
green-winged teal, blue-winged teal, can-
vasback, and lesser scaup.
Data for black ducks banded at Lake
Chautauqua and at McGinnis Slough and
for mallards banded at McGinnis Slough,
tables 2, 3, and 4, showed no significantly
greater hunter kill in one sex than in the
other for the period of study. Data for
mallards banded at Lake Chautauqua, ta-
ble 1, showed a greater hunter kill in
drakes than in hens; the difference in
hunter kill between the sexes was statis-
tically significant and similar to that for
mallards banded in Canada, table 28.
In most species in which hunting takes
a greater toll of one sex than of the other,
the male segment bears the greater loss.
However, the effect of hunting on the sex
ratios of the entire North American duck
population is probably insignificant.
Disease and Sex Ratios.—Although
numerous diseases afHict ducks, only three
are known to cause large losses among
these birds: (1) botulism, (2) fowl chol-
era, and (3) lead poisoning.
Botulism.—Botulism in ducks occurs
in both Canada and the United States; it
is most prevalent among the populations
in the Prairie Provinces, the Northern
Plains States, and the Western States.
The time of botulism outbreaks usually
is from midsummer to early autumn.
According to Hammond (1950:213),
There appears to be no selectivity of sexes
as far as Clostridium toxin is concerned and
the ratio of sexes appearing in the studies is
a reflection of the differential utilization. If
males were attracted to areas at a time when
toxin was potent and available a preponder-
ance of males appeared in the collection.
+
bo
bo
Entire Periop
Aucust 29-
SEPTEMBER 4
Aucust 7-14 Aucust 15-21 Aucust 22-28
Jury 28-
Aucust 6
|
|
Jury 21-27
Table 29.—Drake percentages in seven species of ducks found dead or incapacitated, presumably from botulism, at Whitewater Lake, Manitoba,
Jury 14-20
in 7 weeks of 1949.*
Ittinoris NaturAL History Survey BULLETIN Vol. 27, Art. 6
% feat eyre! hae Hammond (1950:212) found a ratio of —
& és Sard a te 161 drakes to 100 hens among 8,395 adult —
a ducks affected by botulism on four national —
ee a wildlife refuges in North Dakota, 1937-—_
ee = so 1947. The relative number of hens in- |
= creased progressively from July through
September. |
An inspection of ducks that presumably —
were victims of botulism at Whitewater
Lake, Manitoba, between mid-July and —
early September, 1949, revealed a prepon- —
derance of drakes, table 29. There was an
increase in the proportional number of
hens among the victims in some species in~
late August; however, the hens in most
large lakes with extensive marshes ap-
pears to expose drakes more than hens to
botulism toxin. The worst known botu-
lism areas, such as Whitewater Lake in
Manitoba, Johnstone Lake in Saskatche-
wan, Medicine Lake in Montana, and
the marshes about Great Salt Lake, Utah,
are places where drakes, in much greater
numbers than hens, annually gather for
the wing-molt.
Fowl Cholera—In North America, t
©
: species did not suffer severe losses, possi-
bu tlee i aces g bly because the disease abated in early
ate = ia < 5 September, before large numbers of hens —
: » arrived.
ruSloo iw a mvs Waterfowl afflicted with botulism at
Agelos is g sicle the Ogden Bay Bird Refuge, Utah, in
= : z 1944 and 1950 and at the Bear River Mi-
ee = gratory Bird Refuge, Utah, in 19527
55: g|/SG :% A %=| 2 showed a preponderance of drakes among
ZA” a : 4 both adults and juveniles, tables 21, 22,
“ie 5 and 23. A comparison of the sex ratios
2a ee eee tees ~ of ducks dying from botulism in late sum-
OG [Seon oe RF mer of 1944, table 21, with those killed
= by hunters during autumn of the same
4 ee bag re
Ess #4Ee S Vol; year, table aC indicated ue pak He
yas =) ta eal ba “| 5 proportionally greater numbers of drakes
= among the birds dying of the disease. The
= : g the g The
Zee lncot a ne * fact that, in Utah, drakes were relatively
BOs Sxse & RS! Ee more abundant late in the summer than
g during the autumn may have accounted,
Enuticenm 92 om = at least in part, for relatively higher num-
ee - ars Be ear Sete lee 2 bers of drakes among disease victims than
= among shot birds.
a .
weglannn © on 5 The habit of drake dabblers, while un-
ASE sags ¢ gels dergoing the eclipse molt, of frequenting
c
é
A
2
o
tS}
E
4
6
roa
a
2 S|
z
3
°
=
is]
vo
a
E mel Tjareya Poa eae largest losses of migratory waterfowl ‘roti
is = irs sees Erreee fowl cholera appear to be those reported
o — Gre «Sos ‘i
a ed G5 eo ee for the Panhandle of Texas by Petrides &
& ZSfecaiue 3
Bee eessys Bryant (1951:193). Other severe losses
ZOMHO M H from this disease have been reported from
August, 1961
the south end of San Francisco Bay
northward through the delta and into
the lower Sacramento Valley (Rosen &
Bischoff 1950:147-8).
Although Petrides & Bryant (1951:
203) found some indication that the
smaller the duck the more susceptible it
is to fowl cholera, the weight difference
between drakes and hens in any one spe-
cies is not great enough to account for a
material difference in mortality rates. A
small number of drake-hen ratios for mal-
lards and pintails, living birds and victims
of fowl cholera, in the Texas Panhandle
in 1944-1946, table 30, suggest that the
disease is not markedly selective of either
Sex.
Sex ratios for several hundred ducks
presumably dying from fowl cholera in
the Texas Panhandle in 1944-1946 and
1948 are given in tables 30 and 31. The
loss of pintail drakes was proportionally
greater in 1948 than in 1944-1946. The
loss of mallard drakes showed approxi-
BELLROSE ef¢ al.: SEX RATIOS AND AGE Ratios
423
mately equal percentages in the two pe-
riods. In each period, the loss was pro-
portionally greater among pintail drakes
than among mallard drakes.
Available evidence suggests that fowl
cholera is not an important cause of dif-
ferences in mortality rates between the
sexes. In the recorded outbreaks of this
disease among ducks, drakes have predom-
inated in the populations and have suf-
fered losses proportionally no greater than
those of hens.
Lead Poisoning—Among_ migratory
waterfowl, lead poisoning is more wide-
spread geographically than either botulism
or fowl cholera. It has been estimated
(Bellrose 1959:282) that among all spe-
cies of waterfowl in North America 2 to
3 per cent die from this disease each year.
Following experiments with penned
wild mallards, Jordan & Bellrose (1951:
21) concluded that:
The hen mortality from lead poisoning was
found to be double the drake mortality, except
Table 30.—Drake percentages among pintails and mallards in the Panhandle of Texas,
1944-1946, as determined by (1) counts of ducks believed to be victims of fowl cholera and
(2) visual observations of healthy ducks.*
PINTAIL MALLarD
Visual Visual
PERIOD vations : vations
ae a Per Cent | Per Cent rs Per Cent Per Cent
Dhacks Drakes Drakes ites Drakes Drakes
Miarch:4—16, 1944...5...... 311 + oll seteae eects 187 EY ieee Uhl incite aeoene ee
Bebe 1819456 os ask ee 552 55 56 281 51 48
er chel O94! Fe cee Ss DEY) 64 65 64 70) tm ere ene tes
Feb.—March, 1946.......... 1,008 63 71 346 E16, Wha ean ore oon
*By Arthur S. Hawkins and U. S. Game Management Agents L. J. Merroka, Floyd A. Thompson, and M.
H. Boone.
Table 31.—Drake percentages in four species of ducks found dead, presumably from fowl
cholera, on areas in the Panhandle of Texas, winter and early spring, 1944-1946 and 1948.*
1944-1946 1948
SPECIES
Number Per Cent Number Per Cent
of Ducks Drakes of Ducks Drakes
ae PELE 878 Ce en ee er 54.4
SPC Cemee te ee eMne me tetas aredehrsiees fll eben decane cfetets a: [apr e navel SENG 860 62.6
LEI et a rar Oe ae a 2,093 62.1 7,447 Oil
Beenie COBLe a lmeree mn ear llr nee erence leek soe als Meas, 192 SES
*Data for 1944-1946 from table 30. Data for 1948 from U. S. Game Management Agent L. J. Dugger.
424 ILLINOIS NATURAL
Table 32.—Drake percentages among mallards picked up dead or incapacitated from lead if
History SurvEY BULLETIN
Vol. 27, Art. 6
poisoning in several areas of the Mississippi Flyway during late fall and winter, 1939-1955.
PLace
Sand Lake- South: Dakotas: . ch siete ee Reine
Heron: Lake; Minnesota: 5045.5 jas cee seit Vas
Lake Chauteuaua, Hingis. < suk nies» es aes ws
Daivhitowis Magn oi os oe ea ea ee is Oe an a ies
Chaniten County, Missoan os eacc suse cae
Claypool Reservoir, Arkansas..............6.+--
Catshanls Rake, Lois onaies. } oe ise sie et'es
4 NuMBER Per Cent
YEAR CHECKED DRaAKES
1951 59 57.6
1939 194 63.4
1941-1955 753 62.8
1953 47 68.1
1949 53 64.2
1954 100 73.0
1953 243 44.4
in the spring season when hens entered the
breeding phase. At this season the food in-
take of penned wild hens increased steadily
until it equaled, then exceeded, that of penned
wild drakes. During this period hens proved
to be less susceptible to lead poisoning than
were drakes. At all other seasons hens ate
less food than did drakes.
In field experiments with mallards,
some of which had been dosed with lead
shot and some of which had not been
dosed, Bellrose (1959:276) found that:
Because of the smaller number of experi-
ments conducted with hens than with drakes,
it is more difficult to appraise mortality from
lead poisoning in the hens. However, the
available data suggest that, among hens and
drakes with identical ingested shot levels, hens
probably suffer twice as great a mortality as
drakes in the fall and a small fraction of the
mortality of drakes in late winter and spring.
Actual counts of mallards picked up
dead or incapacitated from lead poisoning
in the Mississippi Flyway during late
fall and early winter show a large pre-
ponderance of drakes, table 32. Field
observations on healthy ducks in the re-
gion also show a preponderance of drakes
in the wintering populations. Because
most outbreaks of lead poisoning that
have been reported are from the northern
periphery of the wintering grounds and
because drakes greatly predominate in
wintering populations in those areas, un-
doubtedly an appreciably greater number
of drakes than of hens have died from
this disease.
Predators and Sex Ratios.—Inves-
tigations of predation on waterfowl are
not adequate to provide a substantial basis
for appraising the role of predation in se-
lective mortality for drakes or hens. The
hens, while incubating eggs for 3 or 4
weeks, and later, in caring for the flight-
less young for 6 to 10 weeks, may be ex-
posed to greater predation than drakesil
During the molt or flightless period, when —
the tendency of hens is to remain on small _
bodies of water, while drakes congregate
on large lakes or marshes, the hens may —
be subjected to greater predation thal y
Moreover, the poor physical con- ;
drakes.
dition resulting from the stress of egg
laying and molting may also cause the
hens to be more vulnerable to sredatioull
Kalmbach (1937:383-4), in summa-
rizing the fate of 512 duck nests on the
prairie breeding grounds in Canada, re- es
ported that eight egg-laying or incubating
hens were known to have been killed by a
Other hens may have been
predators.
killed by predators without leaving evi-
dence; 40 nests had been deserted, and 53 b
had been destroyed by unknown agents.
Ina study that included 340 “active”
duck nests in southeastern Saskatchewan —
during 1953, Stoudt & Buller (1954:
58- 9) found seven nesting hens that had
been killed by predators.
near Minnedosa, Manitoba, Alex Dzubin
of the Canadian Wildlife Service (letter, 4
March 26, 1955) found 13 hens and 6 —
of
Ԥ
During three
seasons on a 1.5 square mile study area
“
a
~
s
fi |
on
2
e
i
drakes killed by predators, mowers, or
muskrat traps.
was atypical in being flanked by paved
Because his study area
highways along two boundaries, as well
as by telephone and electric power wires, —
ducks killed by colliding with cars or by
flying into wires were not included in his
figures.
During a study of the fate of nests on
farm land near Delta Marsh on the Por- —
tage Plains of Manitoba, 608 nests of
seven species of ducks were examined —
although —
many nests were believed to have been
(Milonski 1958:223, 225);
lost to predation (striped skunks de-
August, 1961
stroyed 7 per cent of the pintail nests and
51 per cent of the mallard nests) only five
hens were known to have been killed by
predators.
On Illinois study areas, raccoons de-
stroyed 304 out of 1,579 wood duck nests
and killed 103 hens in a period of 7 years.
Minks killed other nesting wood duck
hens, and even fox squirrels were respon-
sible for the death of several hens. Census
records indicate that during the nesting
period wood duck drakes suffered negligi-
ble losses.
Agricultural Operations and Sex
Ratios.—Losses resulting from mowing
or combining operations on farm land are
selective for nesting hens. Such _ losses
would affect only species nesting in crops
subject to mowing or combining. It seems
probable that the mallard, pintail, gadwall,
green-winged teal, blue-winged teal, bald-
pate, and shoveler would be most exten-
sively concerned. The potential loss of
nesting hens is great, because extensive
areas of farm land are included in the
breeding grounds. As long ago as 1948,
Lynch (1948:28) pointed out that the
75,000 square miles comprising southern
Saskatchewan is far from being a vast
undisturbed prairie and that “three-fourths
of this ‘Duck-Factory’ are grain-fields.
The remainder is heavily grazed.”
According to Forrest Lee of the Min-
nesota Department of Conservation (let-
ter, January 9, 1955), the loss of blue-
winged teal hens from mowing may be
appreciable in Minnesota. One farmer
near Hutchinson, despite the use of a
flushing bar, in 1 year destroyed three
hens while he was mowing an alfalfa field.
A normally productive pond on his farm
had no broods in that year. Interviews
with a large number of farmers in the
area indicated that such losses were not
unusual.
Of 122 mallard and blue-winged teal
nesting hens for which there was a chance
of being killed (on nests destroyed directly
or indirectly) in the mowing of 592 acres
of hay on Horicon National Wildlife
Refuge, Mayville, Wisconsin, only 5
were killed (Labisky 1957:195-7). It
was believed that this low vulnerability
of nesting hens resulted because “dabbling
ducks generally rise swiftly and nearly
vertically from the nest when flushed by
BELLROSE e/ al.: SEX RATIOS AND AGE RATIOS
425
the mowing machine, thus avoiding the
cutting bar.”
While making observations on 608 nests
of seven species of ducks on farm land
near the Delta Marsh in Manitoba, Mil-
onski (1958:223) found only two hens
killed in mowing operations.
The available data indicate that losses
of nesting hens resulting directly from
agricultural operations do not contribute
importantly to imbalance in adult sex
ratios.
Stress and Sex Ratios.—Little is
known about stress, as defined by Selye
(1956:3), in its relation to mortality in
ducks. Kabat et al. (1956:44) found
that in pheasants (Phasianus colchicus)
the “seasonal variation in resistance to the
applied stress and survival time was re-
lated to the physiological condition of the
hen at particular times of the year.” In
July and August, pheasant hens that had
completed or were about to complete their
egg laying and were molting flight feath-
ers were in their poorest physical condi-
tion of the year. Survival of pheasant
hens under applied stress was shortest in
June, July, and August and longest in
April, immediately prior to egg laying
(Kabat et al. 1956:12). The average
survival period in July was 13 days in one
year and 18 days in another, compared to
21 days in October, 27 days in Decem-
ber, 29 days in January, 34 days in Feb-
ruary, 40 days in April, 22 days in May,
17 days in June, and 13 days in August.
Without doubt the greatest energy
drain experienced by duck hens in the en-
tire year occurs during late spring and
summer as a result of egg laying, in-
cubation, brooding of young, and _ post-
nuptial molt. This sequence of activity
probably places the hens in much greater
jeopardy to stress than the drakes, which
experience marked depletion of energy
only through the period of the post-nuptial
molt.
Harold C. Hanson of the Illinois Nat-
ural History Survey has determined
(manuscript in preparation) that among
Canada geese (Branta canadensis) the
stress of the molt is especially severe on
the female following the energy demands
of egg laying and caring for the young and
that this produces a differential effect on
the sexes which may be the primary cause
426
for the preponderance of males in adult
populations.
Evaluation of Mortality Factors.—
Information available on the principal
mortality factors affecting sex ratios in
the North American duck population indi-
cates that hunters and disease take rela-
tively more drakes than hens and that
predators may take relatively more hens
than drakes.
From the time of hatching to the be-
ginning of the breeding season, only slight
Ittinots NATURAL History SurvEY BULLETIN
Vol. 27, Art. 6
the imbalance between the sexes in this
population.
Influencing the age composition, and
therefore to a large extent the sex ratios
of the population, are (1) productivity
and (2) mortality.
The more productive a species of water-
fowl, the greater is apt to be the propor-
tion of juveniles in its population at the
opening of the hunting season.
greater the proportion of juveniles in a
population, the more nearly balanced is
Table 33.—Shooting losses, as measured by per cent of banded ducks recovered in year
of banding, and drake percentage in the population of each of seven species of ducks.
Per CrNT OF
NuMBER OF Banpep Ducks DRAKE
SPECIES Ducks BAaNnDED* RECOVERED IN PERCENTAGE IN
YEAR OF PopuLaTiont
BaNnDING*
Dabbling Ducks
Malland's S¥ cen. ett eon eae 22,636 10.0 52.6
Pa oe he eer ere 2,020 8.7 54.6
Pita vos oe Staea ee eee 9 O51 6.1 59.4
Shoveler so: 206 ie ek ese oe ak 749 5:9 60.1
Diving ducks
ReaieA separa kae ns so ee toe eee 2,067 13.1 60.2
Canvasbackee <4 702 P28 sci Tae tee 531 1252 66.4
Lesser aeaues 220. 63 a ES ees tts 6,567 6.7 69.5
*Data from waterfowl bandings on Canadian breeding grounds by Ducks Unlimited (Cartwright & Law, 1952:10-1).
4.
{Data from summary column, table
changes take place in the sex ratios of the
yearling class of a duck population. Mor-
tality factors that operate through most of
the first year of life affect the two sexes
about equally or the drakes slightly more
than the hens. Available information is
not sufficient to permit appraisal of the
influence of predation on sex ratios. How-
ever, during the breeding season appreci-
able losses occur among hens; these losses,
most of which appear to be attributable to
predation, agricultural operations, and nat-
ural stress, may account for the predomi-
nance of drakes in the adult class.
Sex Ratios and Age Composition
of Populations
The age composition of a duck popula-
tion is reflected in its sex ratios. Because
of an approximate balance between the
sexes in the juvenile class and an appre-
ciable imbalance in the adult class, the
greater the proportion of old birds in any
given population, the greater is apt to be
its sex ratio. Some species of ducks are
consistently more productive than other
species.
hence, high mortality rates.
An inverse relationship between shoot-
See beeps
The
Most of the highly productive —
species have high shooting losses and, —
ing losses and the size of the drake seg-
ments is shown in table 33 for four spe- _
cies of dabbling ducks. The higher the ~
shooting loss, the smaller is the imbal- —
ance between the sexes in these species.
Some species of ducks suffer excessive
hunting losses in the juvenile age class.
Mortality in the fall is so high in the
juvenile class that birds over a year old
greatly predominate in the spring popula- —
tions. In these species there is a great im- __
balance in the sex ratios of spring popu-
lations. High vulnerability to hunting is
shown in table 45 for juveniles of two
species of diving ducks, the redhead and
the canvasback.
Of the redhead, Hickey (1952:80)
concluded that, “in the past,” the kill |
August, 1961
rate for juveniles has been about 50 per
cent, whereas the kill rate for adults has
been 20 or 30 per cent; the annual mor-
tality rates have been about 70 per cent
for juveniles and about 55 per cent for
adults. Of the canvasback, Geis (1959:
254-5) reported that the year-of-banding
recovery rates (per cent of birds banded
that were shot by hunters and had bands
recovered within a year of the time of
banding) were 22 per cent for juveniles
and 14 per cent for adults; the annual
rates for mortality from all causes were
77 per cent for juveniles and 35 to 50 per
cent for adults. Mallard drakes banded
as juveniles in Illinois had a first-year
mortality rate of about 55 per cent; mal-
lard drakes banded as adults had a first-
year mortality rate of 36 per cent and an
average mortality rate of about 40 per
cent (Bellrose & Chase 1950:8-9).
The high mortality rate in the juvenile
class of redheads and canvasbacks has re-
sulted in relatively large numbers of old
birds in the breeding populations of these
species and consequently a large prepon-
derance of drakes, table 33.
Extremely large drake segments noted
in lesser scaup populations are evidently
not related to high juvenile mortality re-
sulting from hunting. The vulnerability
rate of juveniles in this species, table 45,
is insufficient to account for the large im-
balance between the sexes, table 33. The
causes of the imbalance seem to be (1)
low shooting pressure on the species, ta-
ble 45, (2) a low reproductive rate, table
62, and consequently (3) a relatively
small number of juveniles in the popula-
tion, table 53.
Variations in the age composition of
waterfowl populations are largely respon-
sible for variations in sex ratios among
species of ducks. Sex ratios of various
species of ducks in the spring in North
Dakota, table 24, indicate that the mal-
lard has relatively the largest number of
yearlings in its breeding populations; this
species is followed in order by the pintail,
shoveler, redhead, blue-winged teal, ring-
necked duck, baldpate, canvasback, lesser
scaup, and ruddy duck.
The Question of Surplus Drakes
It seems reasonable to question the
value of those drakes in excess of the
BELLROSE et al.: SEX RATIOS AND AGE RATIOS
427
number needed to provide mates for the
hens in waterfowl populations. In the
event such drakes do not play an essen-
tial role in species survival, an effort
should be made to provide for their utili-
zation.
While drakes outnumber hens in all
species studied, drakes occur in relatively
greater numbers among the diving ducks
than among dabblers, table 24. Exam-
ination of available knowledge on the re-
productive biology characterizing these
two subfamilies reveals nothing which
suggests that extra drakes may be more
essential to the maintenance of popula-
tions of diving ducks than of dabblers.
The hens of diving ducks engage in
less renesting activity than do the hens of
dabbling ducks, and some observers feel
that diving duck drakes tend to be more
persistent in remaining with nesting hens
than do the drakes of dabbling ducks. Spe-
cies differences in this respect were ob-
served among dabbling ducks by Sowls
(1955:101), who wrote that while
late-season or renesting courtship flights of
mallards, gadwalls and pintails were common,
we seldom saw them in the shovellers and
blue-winged teal. I suspect that the difference
occurred because of the length of time the
drakes stayed with their hens after the clutches
were laid. Blue-winged teal and _ shoveller
drakes did not abandon their hens until incu-
bation was well advanced; while mallard, pin-
tail and gadwall drakes abandoned their hens
shortly after the clutches were completed.
Robert I. Smith of the Illinois Natural
History Survey (personal communica-
tion, December 9, 1960) also observed
that blue-winged teal and shoveler drakes
tend to remain with their hens longer than
do the drakes of mallards, pintails, and
gadwalls; in exceptional cases, mallard,
pintail, and gadwall drakes may remain
with their hens throughout and even be-
yond the incubation period. On the breed-
ing grounds, drakes outnumber hens to a
greater extent among pintails, blue-winged
teals, and shovelers than among mallards
and gadwalls, table 34. A pattern of sorts
seems apparent here, but it does not afford
obvious support of a need for extra drakes
in reproduction.
The superficially excessive number of
drakes may be significant to population
dynamics among waterfowl in ways
which are not directly related to the in-
surance of successful reproduction. At
428 Ittinois NATURAL History SurRVEY BULLETIN
times, harassment of nesting hens by idle
drakes may result in an important amount
of nest desertion and possibly a reduction
in productivity. Along with the severe
stress of reproductive activity, harassment
by drakes may contribute indirectly to
mortality among hens. It is conceivable,
too, that, if extra drakes are truly sur-
plus, they may also create undesirable
stress by occupying space and consuming
food essential to the welfare of the pro-
ductive segment of the population.
Perhaps insight into the value of extra
drakes could be obtained through an ex-
perimental procedure designed to reduce
the number of drakes in a subpopulation of
a species having a large drake segment. Re-
duction of drake numbers could possibly
be accomplished by deliberate hunting of
drakes in places and at times when they
were concentrated apart from the hens or
when they could be decoyed from the hens
and brought within shooting range. Tep-
lov & Kartashev (1958:159, 161), re-
porting on observations made on the Oka
State Sanctuary and on adjacent shooting
areas in Russia, indicated that hunters
are “permitted in spring to obtain the
drakes of all species and also geese on
passage. The most general method of ob-
taining waterfowl in spring is the shoot-
ing of Mallard drakes which go to a de-
coy duck.” In Russia, the killing of fe-
male ducks is forbidden in spring. Such
an experiment as that outlined above
would meet the added objective of deter-
mining whether regulated hunting might
be directed at what is possibly a truly ex-
pendable part of the waterfowl popula-
tion.
Sex Ratios as Measures
of Production
Because sex ratios reflect the age com-
position of a duck population, analysis of
year-to-year differences in the sex ratios
of a species offers a method of diagnosing
the yearly changes in production. Also, be-
cause sex ratios for each species of water-
fowl vary from season to season within
any year, as a result of hunting and nat-
ural phenomena, the sex ratios obtained
during a particular season (fall, winter,
spring, or summer) should be compared
with the sex ratios obtained during only
corresponding seasons of other years. A
Table 34.—Drake percentages in 12 species of ducks observed in the breeding grounds region of North America, 1935-1942, 1947—1950.*
Norts Dakota
MANITOBA
MINNESOTA
SASKATCHEWAN
SPECIES
Bie | SOC eel arlene Ml evans
53.9
62.8] 60.6f| 61.91] 50.0 | 50.0 | 51.1
“BSS 153.3 1-8059. | 162: 5.
74.34] 77.14] 58.71] 51.3 | 56.5
5552 1:54:57 | S75
Mallard... x) IE bee
Gadwalleic ee te oa oe
Baldpates.s cosets sie
Pintail....
Green-winged teal......
"50.6 | 61.7
ay RGR om ce eect ap ate ee Mg) ALS Wh yee base
52.5 | 56.8
55.0 | 55.4 | 50.8
59a S78
Blue-winged teal...............
53.2
Shaveler.: sere nos
56.6 | 51.9 | 58.6 | 53.3
58.8 | 64.6 | 57.9
54.4 | 61.4
58.5 | 57.6 | 58.9
Vol. 27, Art. 6 ©
55.5
[Retro a (atta fe eeeg eee per ae
Ring-necked duck......
60.4 | $5.1
66.6 | 74.2 | 50.0 | 69.3 | 66.3 | 65.0 | 64.3 | 66.6 |......
60.9 | 61.0 | 74.4 | 70.6 | 69.4 | 62.0 | 69.0 | 67.7 | 64.3 | 76.0 | 74.0
77.4 | 69.5 | 69.6
Canvasback.........
S71
61.1
Lesser scaup....
Ruddy duck...
(1935:278; 1938:22); Minnesota, Erickson (1943:27); Manitoba, Hochbaum (1944:15); North Dakota, M.
ce (personal communicati:
: Saskatchewan, Furniss
regions
e Servi
*Sources of data for the various
C. Hammond, U. S. Fish and_Wildlit
August, 1961
75
50
PER CENT
25
1941 1945
1943
1939
BELLROSE et al.: SEX Ratios aND AGE RATIOS
429
Hens
loud
e
—-—— Juveniles
Hens
Juveniles
rv
@
ee
1947 1949 1951 1953 1955 1959
Fig. 9.—Year-to-year changes in the hen percentage and in the juvenile percentage in mal-
lards checked in hunters’ bags in the Illinois River valley, 1939-1955 and 1959. Percentages have
been adjusted so that the means for juveniles and hens are equal.
comparison of the sex ratios in the sum-
mer of one year with the sex ratios in the
winter of the same or another year would
be biased by the disproportionate hunting
losses of juveniles, which have approxi-
mately balanced sex ratios.
As a means of measuring yearly pro-
duction, sex ratios have certain basic ad-
vantages over age ratios. For many spe-
cies of ducks, such as the divers, age ratio
data, derived from bag checks during the
autumn, are difficult to obtain in ade-
quate numbers. For the most important
species, it is much easier to obtain large
samples of sex ratio data from field ob-
servations than to obtain large samples of
age ratio data from bag inspections. Less
skill is required to determine the sex of
a duck in nuptial plumage than the age of
a duck in any plumage.
To test the validity of sex ratios as cri-
teria of duck production, we have made
a comparison, fig. 9, of sex ratios with age
ratios, which are direct reflections of pro-
duction. Both ratios were obtained from
mallards killed by Illinois hunters in 1939-
1955 and 1959. We have also made, for
several species of ducks, comparisons of
sex ratios derived from observations on
the breeding grounds, table 34, with the
number of juveniles per hen killed in
Illinois, table 62.
As shown in fig. 9, the sex ratios (per
cent hens) and the age ratios (per cent
juveniles) obtained from mallards killed
by Illinois hunters differed markedly in
several years. The fluctuations in age ra-
tios tended to be of greater magnitude
than those in sex ratios; the peaks were
higher in age ratios than in sex ratios,
and the troughs were deeper. An over-all
correlation of +0.59 suggests that only
fair agreement exists between the sex ra-
tios and the age ratios. We conclude that
sex ratios derived from bag inspections
provide a fair index to productivity but
not so good an index as age ratios.
Sex ratios obtained on the breeding
grounds, table 34, do not appear to pro-
vide a more reliable index to production
than sex ratios calculated from bag in-
spections in Illinois. Data for the breed-
ing seasons of 1935-1942 and 1947-1950
(except certain data from Furniss, table
34) show that the drake percentages for
the mallard, gadwall, pintail, green-
winged teal, and ring-necked duck did
not, in any season for which figures are
available, deviate from the average for
the species by as much as 5 per cent. This
lack of deviation indicated relatively sta-
ble populations; data in table 62, showing
the number of juveniles per adult hen for
the years 1946-1949, indicated increasing
430
populations for all of the above-men-
tioned species except the gadwall.
AGE RATIOS
Two commonly used indicators of
waterfowl production are brood densities
(the number of broods per unit of area on
the breeding grounds) and age ratios
(the mathematical relationship between
adults and juveniles old enough to fly).
Brood density surveys supply informa-
tion of value for making preseason ad-
justments in hunting regulations. How-
ever, data on brood densities are not be-
lieved to constitute precise indices of pro-
duction. Substantial proportions of the
broods present in an area are missed by
observers employing survey techniques us-
ually considered practicable (Anderson
1953:8-10). Correction for unobserved
broods may never yield to reliable stand-
ardization, for the percentage of broods
not found by observers varies with many
factors such as time of day, time of season,
habitat, area, and waterfowl population
densities.
Age ratios are believed to afford a more
promising basis than brood counts for
measuring waterfowl production, although
they, like data on brood densities, are
seldom true indices of production.
This section of the paper is written
with the intention of opening the way to
a more effective use of age ratios in wa-
terfowl management. The following as-
pects of age ratios and their use are con-
sidered: age criteria, sampling methods
for obtaining age ratios, seasonal and re-
gional variations in age ratios, factors
tending to bias age ratios, age ratios as
measures of production, environment in
relation to production, production in dif-
ferent species, and the place of age ratios
in population management.
Age Criteria
In 1938, when biologists of the Delta
Waterfowl Research Station at Delta,
Manitoba, and of the I]linois Natural His-
tory Survey at Havana, IIlinois, initiated
waterfowl research programs involving
the inspection of large numbers of ducks
bagged by hunters, the need for finding
consistently reliable external characteris-
tics by which to separate juveniles from
ILttino1is NATuRAL History SurveEY BULLETIN
Vol. 27, Art. 6
adults was recognized. The best external
indication of age known at that time had
been pointed out by Pirnie (1935:275).
It was based on the appearance of the tips
of tail feathers, those of adults being
rounded or pointed, those of juveniles be-
ing blunt or notched. However, in the
mallard, an important species in Illinois
and at Delta, young birds were known to
replace their juvenile feathers with adult
feathers early in the fall; hence, they
could not be accurately aged by this char-
acteristic throughout the hunting season.
In some species, notably those in the genus —
Aythya, the tail feather criterion was
found to be more persistent than in the
mallard, but, even so, it was not reliable
throughout the hunting season.
During the fall of 1938, biologists at
the Delta and Illinois stations searched
for some characteristic by which to sep-
arate juveniles from adults in the mallard
and other early-molting species.
search at Delta was concentrated on plum-
age, while that in Illinois was concerned
with a character, pointed out by Tice-
hurst (1938:772-3) as being related to
immaturity: striae “at the tip of the nail
of both upper and lower mandibles.” The
Illinois group also investigated various
parts of the skeleton that might exhibit
differences in ossification between juve-
niles and adults. At that time, neither
group was successful in the search for a —
characteristic by which to separate ducks
into the two age classes.
In the following winter, Gower (1939: i "
427) called attention to the bursa of Fa-
bricius as a criterion of age in ducks. A
short time later Hochbaum (1942:301),
aided by the findings of Gower and the
work of Owen (1866:244—-5), learned —
that juvenile drakes of 5 to 10 months of —
age could be separated from adult drakes
by the size of the penis, fig. 1. This find-
ing, put to use in the summer and fall of
1939, provided a method of differentiat-
ing between juveniles and adults of both
The new method —
proved faster and easier to use than the —
bursal method. Also, it provided for ac- —
curate separation of drakes from hens in ~
all stages of plumage. However, the bursa —
live and dead drakes.
was found to persist for several weeks
after the transition from juvenile- to
adult-type penis and therefore provided a —
The i
August, 1961
basis for separating juveniles from adults
over a longer period of time than that af-
forded by the penis.
Hochbaum (1942:303-4) pointed out
that the oviduct, which opens into the
cloaca in adult females, is sealed by a
membrane in immature females, fig. 1.
Wildlife technicians in Illinois have found
80
70
60
50
40
PER CENT JUVENILES
30
20
1939 1941 1943 1945
BELLROSE et al.: SEX Ratios AND AGE RATIOS
A
McGinnis Slough /+/y \
glake Chautauqua
1947
431
collected from duck hunters and shipped
to a central point for interpretation by
trained personnel.
Sampling for Age Ratios
Data on the age ratios of ducks may be
obtained by examination of birds trapped
for banding, shot by hunters, or killed by
a Valley
1953 1957
1955
1949 195)
Fig. 10.—Year-to-year changes in the juvenile percentage in mallard drakes trapped at Mc-
Ginnis Slough and at Lake Chautauqua and in mallards checked in hunters’ bags in the Illinois
River valley, 1939-1957.
that, until at least mid-January, the pres-
ence of a closed oviduct and a bursa un-
failingly indicates a juvenile hen. Occa-
sionally, a hen is found that shows an
open oviduct and a small bursa; such a
bird is considered adult. Most wildlife
technicians have restricted their aging of
hens to individuals that have been bagged
by hunters. However, Hanson (1949)
developed a technique that can be used
for aging live females in both ducks and
geese.
In 1958, after completion of most of
the field work for the study reported here.
Carney & Geis (1960:376-9) found that,
in certain species of ducks, juveniles and
adults could be identified with a high de-
gree of accuracy on the basis of differ-
ences in the wing plumage. The technique
described by these authors makes possible
the extensive sampling of age ratios of
ducks in all four flywavs of North Amer-
ica. Large numbers of wings could be
disease. It seems desirable that the rela-
tive merits of these sources of data be ap-
praised. In the present study, all three
sources of data were used for obtaining
age ratios.
Examination of Trapped Ducks.—
A comparison of the age ratios of mallard
drakes trapped at Lake Chautauqua, table
35, and the age ratios of mallard drakes
and hens taken by hunters in the Illinois
River valley, table 36, discloses marked
disparity in the number of juveniles per
adult between the trapped ducks and the
harvested ducks. The data show rela-
tively fewer juveniles among the drakes
trapped at Lake Chautauqua than among
the ducks taken by hunters in the Illinois
River valley, tables 35 and 36 and fig. 10.
However, among drake mallards captured
at McGinnis Slough in traps similar to
those used at Lake Chautauqua, a higher
proportion consisted of juveniles, table 37
and fig. 10, than among mallard drakes
432
trapped at Lake Chautauqua or mallards
bagged in the vicinity of that lake.
Despite marked differences in the size
of samples between trapped and shot mal-
lards, the two sampling procedures indi-
cated similar year-to-year trends in age ra-
tios, fig. 10. The statistical correlation in
the annual changes in age ratios between
mallard drakes trapped at Lake Chau-
tauqua and mallards shot along the IIli-
nois River was found to be significant
70
65
60
55
50
PER CENT ADULTS
45
40
35
30
3rd
OCTOBER
2nd 4th Ist
Ittinois NATURAL History SurvEY BULLETIN
Bag Checks
2nd
NOVEMBER
Vol. 27, Art. 6
(r=+0.96, 13 d.f.) at the 99 per cent
level.
Mallards inspected in hunters’ bags in
the Illinois River valley (1939-1949) and
mallard drakes taken in traps at Lake
Chautauqua (1939-1944 and 1947)
showed similar trends in age ratios for
most of the hunting season, fig. 11. The
trends tended to be parallel except in early
December. The correlation between age
ratios calculated weekly for the samples
Trap Catches
oe
Differences
2nd
DECEMBER
3rd 4th Ist 3rd
Fig. 11.—Week-to-week changes in the adult percentage of the autumn flight of mallards in
Illinois, as indicated by two sampling methods: checks of mallards in hunters’ bags and inspec-
tion of mallard drakes caught in banding traps. Bag data are for the Illinois River valley, 1939-
1949; trap data are for Lake Chautauqua, 1939-1944 and 1947.
EEE LL
August, 1961 BELLROSE et al.:
of trapped and shot mallards was signifi-
cant (r=+0.94, 7 d.f.) at the 99 per
cent level.
Behavior may well account for the large
juvenile proportion in the mallard drakes
taken in traps at McGinnis Slough, fig.
10, and the small proportion in those taken
in traps at Lake Chautauqua. As discussed
Sex Ratios AND AGE Ratios
433
under sex ratios, mallard drakes were ob-
served to be more aggressive than hens in
pushing their way into the traps at Lake
Chautauqua. Perhaps adults shouldered
young birds aside in aggressive efforts to
get at the bait. Lake Chautauqua had a
much greater density of mallards and com-
paratively less natural food than McGin-
Table 35.—Number of juveniles per adult among mailard drakes trapped and banded at the
Chautauqua National Wildlife Refuge, near Havana, Illinois, 1939-1944 and 1947—1959,
NuMBER OF
yc DRAKES
TRAPPED
AND BANDED
_ SB Da ee Mees Se i cae 2,574
2 EQ) eo 4,262
MERI Pe cre ee ericistechacees 3,200
_ tabs = GA nec oon Ber eee 4,859
AL ea ae ee 4,655
PR pera eh. Sue ees sc Sd 2,734
EY) cuca ae Oe 1,481
EU ae Oe ee pce?
MP a rs ooh ora 15) onclce See
SE Eee ee 1,984*
ES Se art 9 oan 3, 801*
BEL mae er che a seas 4,493
PSM eye RN es Oa bss 1,048
Ee ee eee as 901
USS 3 GAS eee 998
UG 5 MG ee 632
| DET pe aoe, Sea ne Ceo 856
ETS oH ye A le ee 736
LESS SARS Bes ates eae 93
APPROXIMATE
Per CENT JUVENILES 95 Per Cent
JUVENILES Per ADULT CONFIDENCE
Limits
42.3 0.73 0.67-0.80
S79 0.61 0.57-0.66
34.1 0.52 0.47-0.56
35.3 0.55 0.51-0.58
40.6 0.68 0.64-0.73
22.6 0.29 0.26-0.32
41.1 0.70 0.62-0.78
eyo 18 LOU 27)
331 0.50 0.45-0.54
34.1 0.52 0.47-0.57
Sli 0.61 0.56-0.65
53.7 1.16 1 09-1E 24
44.9 0.82 0.72-0.92
34.4 0.52 0.46-0.60
41.1 0.70 0.61-0.79
50.1 1.01 0.86-1.17
29.6 0.42 0.35-0.49
25.8 0.35 0.28-0.42
De Ost 0.04-0.18
*This figure differs from the corresponding figure in table 39 because it includes ducks banded with reward bands,
which have shown a higher rate of return than standard bands (Bellrose 1955).
Table 36—Number of juveniles per adult among mallard drakes and hens
checked in
hunters’ bags in Illinois, principally the Illinois River valley, 1939-1955 and 1959.
NuMBER
OF
YEAR Ducks
CHECKED
DSSS ee ee ein ao eae 2,261
D/O) ca eee Seek eee 3, 564
CSAS oe, So aul et ea er 4,481
TOLD. 5 Fede eee ee 1,809
METEOR te ne oe a: 1,422
Oe as RON et ie eae 2,167
OCS tee dee Seen Se eee ee 2,047
Se i ce ere ae Sie
ATL OS Cen Re Pa eee! 814
1 oA a Oe ee ee eo 1,215
SIO) ioe SI ea Ste Es ee 597
SEXO As ae ee 581
IOS i Ee eS ee 819
DDD 1 een a Se OS 1,209
SIS) ane een cae ar £052
DIS Hare Sa a) Lo Se 458
ISSN Soe a Re aR 746
SO Pyare aera ct ts Me aoe ae 247
APPROXIMATE
Per Cent JUVENILES 95 Per Cent
JuveENILES Per ADULT CONFIDENCE
Limits
59.1 1.45 1.32-1.58
Pood 1.42 age ile Sy)
50.3 1.01 0.95-1.08
54.2 1.18 1.07-1.30
66.0 1.94 Po—2 eke
54.3 1.19 1.09-1.30
43.9 0.78 0.67-0.92
2565) a5 1.11-1.40
70.3 2.36 2.03-2.78
76.0 3.18 2.78-3.63
49.2 0.97 0.79-1.18
60.4 Ios) 1.28-1.82
63.1 egAl 1.48-1.99
62.3 65 1.46-1.87
59.6 1.48 1.34-1.63
47.6 0.91 Oe Jalal’
64.1 1.78 1.34-2.22
Soe) 0.34 0.30-0.38
434
ILLino1s NATuRAL History SurvEY BULLETIN
Vol. 27, Art. 6
Table 37—Number of juveniles per adult among mallard drakes trapped and banded at
McGinnis Slough, Cook County, Illinois, 1940-1947.
NuMBER OF APPROXIMATE
Vie DraKES Per Cent JuveENILES 95 Per Cent
TRAPPED JuveENILES Per ADULT CONFIDENCE
AND BANDED Limits
1940 tes an se d pcr emer iste 267 68.5 2.18 1.68-2.85
sek. 5 Catan ates, Cera Ne ae 195 D955 1.47 1.11-1.98
Ne PASS ed rear Si a 1,128 69.0 Dape 1.96-2.54
i % ae SEEN A 2 1,922 67.1 2.04 1.85-2.25
Ae eo Uae tas eeearaionsis 967 65.9 eS 1.69-2.22
hoc a oe naning + Lars ube 1,492 54.9 1522 1.09--1.36
1966 3. esate em a aitoriersit 860 61.5 1.60 1.39-1.85
W987 5 Pe cdne aabtok cos aisisiers 556 74.3 2.89 2.40-3.55
nis Slough. This situation may have re-
sulted in greater competition for food at
Lake Chautauqua and consequently
greater aggressiveness on the part of the
adult mallard drakes. The greater fre-
quency of juvenile drakes in traps at Mc-
Ginnis Slough than at Lake Chautauqua
may have resulted in part from greater
wariness on the part of adult drakes.
With an abundance of natural food at
McGinnis Slough, many adults may have
avoided the traps or ignored the foods
they contained. Apparently, in one case
(Lake Chautauqua) the traps were se-
lective for adults while in the other (Mc-
Ginnis Slough) they were selective for
juveniles.
There was a significant correlation at
the 99 per cent level between the age
ratios of drake mallards trapped at Mc-
Ginnis Slough, table 37, and the age ra-
tios of mallards taken by hunters in the
Illinois River valley, table 36 (r= +0.93,
6 df.).
Data obtained from retrapping mallard
Table 38.—Number of adult and of juvenile mallard drakes trapped and banded and thei
drakes previously trapped and banded at
Lake Chautauqua, table 38, indicated that —
the banding traps there were selective,
sometimes for juveniles and sometimes for
adults. During the period October +24,
juveniles re-entered the traps with greater —
frequency than adults (X?=31.14, 1 d.f., _
significant at the 99 per cent level). In
contrast, during the period October 25-_
December 25, adults re-entered the traps —
with greater frequency than juveniles
(X?=12.90, 1 d.f., significant at the same —
level). These retrap data showed that
early in the season, when mallard numbers —
were low and food competition was at a
minimum, banding traps were selective for —
juveniles, but, when mallard numbers —
increased and food competition became —
greater, the traps were selective for adults.
The bulk of the mallard population ar-
rived in Illinois after October 25, and the
banding traps at Lake Chautauqua were
on the whole highly selective for adults.
A correlation, significant at the 99 per
cent level, was found in each year for the —
ret
pS
per cent retrapped during two periods at the Chautauqua National Wildlife Refuge, near
Havana, Illinois, 1940—1943.
iy
/
»
ADULTS JUVENILES -
ates RaTIo OF ki
Per C ie
Number Number or AGI 4
oa ReETRAP-
PeRioD Per Cent Per Cent Pin ce
x d Re- T 7 Re- ER CENT
pie : Re- q trapped oe ; Re- q trapped or J Re
rappe rappe NILFS RE
Banded Banded TRASEGM
Oct. 4-24....... 1,305 297 22.8 1,026 340 28.2 1:1
Oct. 25-Dec. 25.| 9,322 991 10.6 5,265 462 8.8 1:0.83
August, 1961
BELLROSE et al.: SEx Ratios AND AGE RaTIOS
435
Table 39.—Comparative vulnerability (to hunting) of adult and juvenile mallard drakes
banded at the Chautauqua National Wildlife Refuge, near Havana, Illinois, 1939-1944 and
1947-1952; vulnerability measured by year-of-banding recoveries. Ducks banded with reward
bands (Be-lrose 1955) in 1949, 1950, and 1951 were not included in this table.
NuMBER OF DRAKES Y EAR-OF-BANDING rig ee nee PER RATIO OF
BANDED RECOVERIES Cpe Soe ADULT TO
YEAR BONERS JUVENILE
VULNER-
Adults Juveniles Adults Juveniles Adults Juveniles ABILITY
123) eee 1,486 1,088 65 49 22.9 22:32 Pate0s
DAN) See ane 2,647 1,615 132 200 20.1 Sed 1:2.48
MUI she bac 2,110 1,090 57 43 37.0 25.4 1:1.46
j 4D) Se 3,142 il, TAL 216 177 14.6 9.7 hele Sil
ES 2,763 1,892 138 146 20.0 13.0 1:1.54
AE ac a eects 2 617 125 56 16.9 11.0 Le 54
Ss 871 610 31 34 28.1 17.9 EATS,
J 624 708 5 11 124.8 64.4 1:1.94
1 oe 1,286 silks) 46 53 28.0 MWS Lete24
0 449 359 24 Di 18.7 1)53! 1:1.41
Mer ess vais ss 583 325 20 12 29.2 Dalton 1:1.08
S32 er 2,082 2,411 60 151 34.7 16.0 ew atl 7/
PU Years... 2. 20,160 13,624 919 959 21.9 14.2 1:1.54
relative constancy between the age ratios
of mallard drakes banded at McGinnis
Slough and of those banded at Chautau-
qua (r= +0.98, 5 d.f.), tables 35 and 37.
In spite of trap bias, ducks taken in
traps are believed to provide a rough in-
dex to yearly changes in age ratios.
Inspection of Hunters’ Bags.—It
became apparent early in the study that
juvenile ducks were more readily taken
by hunters than were adults. Tests sug-
gested that data obtained by trapping and
banding ducks could be used to correct for
the greater vulnerability of the juveniles.
The following equation was used for this
purpose :
Number of adults banded during
current season but before end of
hunting season
Number of year-of-banding band
recoveries from adults
Number of juveniles banded dur-
ing current season but before end
of hunting season
Number of year-of-banding band
recoveries from juveniles
Vulnerability
quotient V=
An example of the use of the equation
with banding data for 1940 in table 39
follows:
2,647
132 20.1
ans aise) 38a Stas
200
Mallards were banded at one or more
stations in Illinois each year from Octo-
ber, 1939, through 1952, and the data ob-
tained were used for determining the
yearly variations in comparative vulner-
ability of juvenile and adult drakes, tables
39 and 40. Adult drakes banded at Mc-
Ginnis Slough, table 40, experienced rela-
tively greater losses from hunting than
did those banded at Lake Chautauqua, ta-
ble 39. The number of juvenile drakes
banded per juvenile recovery was about
the same at both places. The data indicate
that greater hunting pressure was ex-
erted on adult drakes banded at McGin-
nis Slough than on those banded at Chau-
tauqua.
Black duck drakes banded at McGin-
nis Slough had about the same loss of
juveniles to hunting, table 41, as did mal-
lard drakes banded there, table 40. Black
duck drakes banded at Lake Chautauqua,
table 42, like mallard drakes banded there,
table 39, experienced a lower rate of hunt-
ing loss among adults than did black duck
drakes banded at McGinnis Slough, table
41. Apparently, in mallard and_ black
duck drakes banded at Lake Chautauqua,
the relatively lower hunting losses in
adults resulted from the greater protection
afforded them outside the banding station
area. The Chautauqua National Wild-
life Refuge is about 10 times as large as
436 Ittrnois Natural. History SurvEY BULLETIN Vol. 27, Art. 6
Table 40.—Comparative vulnerability (to hunting) of adult and juvenile mallard drakest
banded at McGinnis Slough, Cook County, Illinois, 1942-1947; vulnerability measured by year- —
of-banding recoveries.
NuMBER BANDED Per
NuMBER OF DRAKES YEAR-OF-BANDING RatTIOo oF
BANDED RECOVERIES Lae pei ADULT TO
YEAR oe JuvENILE
Te VULNER-
Adults | Juveniles | Adults | Juveniles | Adults | Juveniles ABILITY
a I ee eee
14D a heen 350 778 26 66 13.5 11.8 1:1.14
1943s her, 632 1,290 21 57 30.1 22.6 1:1.33
12) 7 ieee hte, arte 330 637 33 67 10.0 9.5 1:1.05
19450. et 673 819 38 69 Nideeilh 11.9 1:1.49
19465. Se ee 331 529 20 41 16.6 12.9 1:1.29
1949o asses aes 143 413 8 29 17.9 14.2 Eh PSs
AL VeGTS vo. eae 2,459 4,466 146 329 16.8 13.6 1:1.24
Table 41—Comparative vulnerability (to hunting) of adult and juvenile black duck drakes 4
banded at McGinnis Slough, Cook County, Illinois, 1940-1947; vulnerability measured by year-
of-banding recoveries.
NumBer BANDED PER
NuMBER OF DRAKES YEAR-OF-BANDING RatTIo oF
BANDED RECOVERIES basso: -BaNDING ADULT TO
ECOVERY
YEAR JUVENILE
VULNER-
Adults | Juveniles | Adults | Juveniles | Adults | Juveniles ABILITY
ISAO ee ee 33 48 4 6 8.3 8.0 1:1.04
194d AF meee 153 253 10 16 15.3 15.8 1:0.97
1949s. hare eee 231 414 15 32 15.4 12.9 1:1
1948. aticok Broce 259 336 8 16 32.4 21.0 1:15
19446 oe Pree whe. 167 323 16 39 10.4 8.3 1:1,.25
LGA ees 166 296 11 31 1551 9.6 1:257
1946) SO 128 257 6 18 DAS 14.3 1:1.49
194 Fae ses 117 271 1 i
All years..... 1,254 2,198 71 167 U7 af, NE Be: PE ee
Table 42.—Comparative vulnerability (to hunting) of adult and juvenile black duck drakes S
banded at the Chautauqua National Wildlife Refuge, near Havana, Illinois, 1939-1944 and
1947-1950; vulnerability measured by year-of-banding recoveries. ‘
NuMBER BANDED PER
NuMBER OF DRAKES Y EAR-OF-BANDING Ratio oF
BANDED RECOVERIES Year or De ADULT TO
YEAR EO JUVENILE
VULNER-
Adults | Juveniles | Adults | Juveniles | Adults | Juveniles ABILITY
MGSO ee reels 55 47 2 2 27s 2555 bE Is
1940S. ed Boke ot 93 68 4 6 2303 19 Us 1:2.06
1 AOE ae aps sea ae on 181 148 1 4 181.0 37.0). |...
19409 og ee 225 123 22 20 10.2 6.2 1Ls1265
| ICSF ie esa aCe ie 188 115 9 9 20.9 12.8 1:1.63
194e a re cores 119 66 I] 8 17.0 8.3 1:2.05
PORTE eS Pett 70 63 ues cbs oy otaie’ dacs | Sala ao x [seaweeds cen nae
SOAS on. Peek 39 7. | EE RO Ie Uae EE Ue
1940 eee ae sie 216 165 3 11 72.0 15.0 1:4.80
L950. yee see. 98 12 4+ 1 24.5 12.0 1:2.04
AN Years So 1,284 855 52 61 24.7 14.0 1:1,76
August, 1961
McGinnis Slough; also, several other ref-
uges occur within the 25- to 30-mile feed-
ing radius of mallards congregating at
Chautauqua, whereas none occurs within
that distance of McGinnis Slough. It
seems evident that adult mallards and
BELLROSE eft al.: SEX Ratios AND AGE Ratios
437
drakes became less vulnerable, table 44,
presumably as a result of increased experi-
ence with hunters. During the early part
of the season, the juveniles were bagged
about four times as readily as adults; late
in the season they were bagged only about
Table 43.—Comparative vulnerability (to hunting) of adult and juvenile blue-winged teal
drakes and hens banded in Illinois at McGinnis Slough, Cook County, 1942-1947, and at Moscow
Bay, Mason County, 1949-1951; vulnerability measured by year-of-banding recoveries.
NumsBer oF Ducks Y EAR-OF-BANDING ae ear PER RATIO OF
BANDED RECOVERIES nea BuEING ADULT TO
YEAR eee JUVENILE
VULNER-
Adults | Juveniles | Adults | Juveniles | Adults | Juveniles ABILITY
Be niaie Site 156 535 i 29 22.3 18.5 eilavil
a hoe 2c. 131 424 2, 16 65.5 26.5 DA
Ey kt, 304 534 8 45 38.0 11.9 1:3.19
5D 193 444 8 23 24.1 19.3 feat 25)
AG eee 90 686 1 9 90.0 76.2 1:1.18
1G) 65 234 1 6 65.0 39.0 1:1.67
ED ene 169 1,071 0 BAF allt etek Err Bi Site alba ea
BWP as chee cy sc, 152 505 A Dp. 76.0 23.0 1:3.30
Reo sos. es 210 1,189 4 33 SDS 36.0 1:1.46
fll years. ... 1,470 5,622 33 Di 44.6 Deeg eee,
black ducks at Chautauqua made good
use of their acquired knowledge of pro-
tected areas.
Blue-winged teals banded at McGinnis
Slough and Moscow Bay experienced
greater differences between the two age
groups in vulnerability to hunting, table
43, than did mallard drakes banded at
Lake Chautauqua, table 39, or McGinnis
Slough, table 40. Although blue-winged
teals are generally considered to be less
wary than mallards and black ducks, the
development of wariness by juvenile blue-
winged teals may be as rapid as that by
juvenile mallards when the birds are sub-
jected to hunting. Vulnerability in the
blue-winged teal, as in other species, prob-
ably is related to the amount of experi-
ence that juveniles have had with hunters.
Most of the juvenile blue-winged teals
arrive in Illinois in advance of the open
season in the northern zone and therefore
are inexperienced with hunters at the time
of their arrival. Most juvenile mallards
and black ducks have been subjected to
hunting by the time they reach Illinois.
Data collected in 1940, 1942, 1943, and
1952 showed that, as the hunting season
progressed in Illinois, juvenile mallard
one and one-half times as readily. Thus,
age ratios obtained from hunters’ bags on
major wintering grounds would be less
biased by the greater vulnerability of juve-
niles than samples taken earlier on breed-
ing or migration areas. The year-to-year
variations in the amount of hunting ex-
perience juveniles receive before they reach
Illinois may be an important factor in de-
termining the year-to-year variations in the
vulnerability of juveniles in this state, ta-
bles 39 and 40. Mallard age ratios ob-
tained from bag checks on the breeding
grounds appear to be the ratios most biased
by juvenile vulnerability, and those ob-
tained on the wintering grounds are prob-
ably the least biased, table 52.
The relative vulnerability of juveniles
and adults of several duck species have
been calculated from recovery of birds
banded on the Canadian breeding grounds,
table 45. The recovery data for the teals
and the shoveler show either no greater
vulnerability among juveniles than among
adults or a greater vulnerability among
adults. However, as recovery data for
blue-winged teals banded in Illinois over
a period of several years show a markedly
greater vulnerability of juveniles, table
438
43,
local conditions affected
I_uinors NATURAL History SuRVEY BULLETIN
it is suspected that some unusual
Canadian
Perhaps
the
bandings of these three species.
Vol. 27, Art. 6
many juvenile teals and shovelers lost
bands, for, until 1957, the banding office’
at the Patuxent Research Center, Laurel,
Table 44.—Seasonal change in comparative vulnerability (to hunting) of adult and juvenile
mallard drakes banded at the Chautauqua National Wildlife Refuge, near Havana, Illinois, in
1940, 1942, 1943, and 1952.
NuMBER OF DRAKES
NuMBER OF REcov-
ERIES FOR WEEK
NumBeErR BaNnDED
Per REcoverRY
Adults | Juveniles | Adults | Juveniles
0 Oo WO oa eee i
1 6 493.0 75.3
8 24 21255 51.0
9 28 363.1 75.4
14 34 350.9 98.9
35 55 181.7 82.9
29 51 276.7 119.9
48 78 203.2 90.1
73 88 141.4 84.1
70 96 149.5 78.0
65 51 163.5 149.5
31 35 343.0 218.1
30 15 354.5 509.0
22 24 483.4 318.1
5 6 2,126.8 PAP) 5)
2 (Onl PREeNeReR Ro
442 591
BANDED
Wek eee 5
Adults Juveniles
Oct “4-108 x. 112 90
Oces TIS eee 493 452
Get: 19-245 25. 1,700 1,224
Oct: 95-Ble 3, 268 ean
Novia tle ivicc a's 4,913 3,363
Novae8-l42... 6, 360 4,561
te | ee 8,025 6,116
Nov. 22-28..... 9,752 7,025
Nov. 29-Dec. 5.| 10,319 7,398
Decin6=12).5 10,464 7,483
Dec. 13-19..... 10,629 7,626
Dec. 20-26..... 10,634 Waoo>
Dec. 27-Jan. 2 10, 634 7,635
i ft es 2. aramid 10,634 7,635
Jan, 10-16: -... 10,634 7,635
Jan. 17-23. 10, 634 7,635
All weeks
Tolan. 10,634 7,035
POCTERE Poa aha SO feat eas Ok Ds eek es dlal| see ES ee
RaTIo oF
ADULT TO —
JUVENILE
VULNER-
ABILITY
ee
00 ht tn
ee Beal
— ee
An UNROOR NW
SH SxuSS& Roa
—
ee oe
_eo
.
ee ee EO ee
Table 45.—Comparative vulnerability (to hunting) of adults and juveniles, both drakes
and hens, of 10 species of ducks banded by Ducks Unlimited* in the prairie provinces of Can-
ada, 1946-1954; vulnerability measured by year-of-banding recoveries.
NumsBer OF Ducks Y EAR-OF-BANDING
BANDED RECOVERIES
SPECIES |
Adults | Juveniles | Adults | Juveniles
Mallard... 28 4,672 10,159
Gadwall........ 133 351
Baldpate....... 491 765
Pintallen nso: oye AY 3,013
Green-winged
fealie rene 391 1223
Blue-winged
rr) RO ene eae 1,809 2,716
Shoveler....... iW 261
Redhead....... 715 358
Canvasback.... 50 125
Lesser scaup... | 393 1,716
NuMBER BANDED PER
Y EAR-OF-BANDING
RECOVERY
Adults
Juveniles
RaTIo OF
ADULT TO
JuvENILE
VULNER-
ABILITY
*Compilation by William Leitch, Chief Biologist, Ducks Unlimited; data are from bandings by field personn:
qualified to separate adult and juvenile ducks.
{This ratio probably incorrect, perhaps partly as a result of loss of bands by newly banded juveniles and unusu
ally heavy losses among juveniles ‘between banding and opening of hunting season.
August, 1961 BELLROSE et al.: SEX RaTIOS AND AGE RATIOS 439
Maryland, recommended size 6 for the
shoveler, although a size 5 is large enough
for that species. Many banders used size
5 to mark green-winged teals, although
size 4 is the proper size. Perhaps natural
mortality was unusually severe in the
young teals and shovelers between the
time of banding and the opening of the
hunting season; very few bands are recov-
ered from ducks that are not bagged by
hunters. Still another possible explana-
tion for unexpectedly low relative vulner-
ability rates for juveniles on the Canadian
breeding grounds has been posed by Rob-
ert I. Smith of the Illinois Natural His-
tory Survey. Smith has observed on the
breeding grounds that fall flocking be-
havior of juveniles differs from that of
adults. Prior to migration, juveniles tend
to congregate, while many adults remain
as single hens of male-female pairs. The
nature and time of this flocking behavior,
Smith believes, varies with species and
with the success and duration of the nest-
ing season. Flock size is probably inverse-
ly correlated with vulnerability, thus tend-
ing to give greater protection to the con-
gregated juveniles than to the single adult
hens or paired adults.
Band recovery data showed pronounced
differences among species in the vulner-
ability rates of juveniles banded in Can-
ada, table 45. Among species other than
the teals and the shoveler, juveniles were
least vulnerable to the gun in the mallard
and most vulnerable in the redhead. Other
data obtained from bandings at national
wildlife refuges also disclosed wide varia-
tions in juvenile vulnerability; they
showed the mallard with a comparatively
low juvenile vulnerability rate, followed
by the pintail, and showed the redhead
with the highest vulnerability rate.
Thus, the gun vulnerability of juve-
niles compared to that of adults was
found to vary by place, time of hunting
season, year, and species.
Gun vulnerability figures for correct-
ing age ratios obtained by checking hunt-
ers’ bags in one or more flyways can best
be obtained by banding adults and juve-
niles in southern Canada just prior to the
opening of the hunting season.
When adequate data from banded
ducks are available, they provide a means
of testing for and, if necessary, correcting
for the relatively greater vulnerability of
juveniles. We believe that age ratios of
ducks obtained from bag samples and cor-
rected for the greater vulnerability of
juveniles offer the best means of deter-
mining the adult-juvenile composition of
duck populations. However, before these
data are used to evaluate production, an
appraisal of the influence of season and
geography on age ratio samples is needed.
Examination of Disease Victims.
——At times, age ratios have been obtained
from large samples of ducks which have
been victims of disease. During fowl
Table 46.—Juvenile percentages among botulism victims in five species of ducks at the Bear
River Migratory Bird Refuge, Utah, during late summer, 1952.*
MALLARD PINTAIL Gee nSeS SHOVELER BALDPATE
EAL
PERIOD Per Per Per Per Per
Num- | Cent | Num-| Cent | Num- | Cent | Num- | Cent | Num-/ Cent
ber Juve- ber Juve- ber Juve- ber | Juve- ber | Juve-
niles niles niles niles niles
August
Ist week...... 48 39.6 486 Ss OE A A erat AAT Ne Bivona alta A Ny | Se Re
2nd week... . 38 52.6 560 COPS | ile 5 Nearer || eral ecm SMe ed Insc cael tet ne etree Pe eae
3rd week... .. 34 44.1 601 61.7 128 41.4 26 OY Pai |e We
4th week... 87 41.4 | 2,392 50.6 651 42.7 94 46.8 26 38.5
September
Ist week...... 29 44.8 | 1,211 44.3 431 43.6 81 | 38.3 65 BPs
2nd week... . 38 39.5 781 47.1 Silt 47.7 107 42.1 62 46.8
*Calculated from data in a report, “Sex and Age Ratio of Waterfowl Afflicted by Clostridium botulinum, Type C,
on the Bear River Migratory Bird Refuge During Summer, 1952,’’ by Jack P. Allen, Utah Cooperative Wildlife Re-
search Unit, Logan.
440
cholera epizootics in wild ducks, records
have been made of the species and sex af-
fected, but little attention has been given
to the ages of victims. In Utah, large
numbers of waterfowl that were victims
of botulism at the Ogden Bay Bird Ref-
uge were classified as juveniles or adults
by Noland F. Nelson, tables 21 and 22,
and ducks lost to botulism at the Bear
River Migratory Bird Refuge were sim-
ilarly classified by Jack P. Allen, table 46.
The degree to which botulism toxin is se-
lective for the two age groups has not
been investigated.
Epizootics resulting in extensive loss of
waterfowl cannot be relied upon as de-
pendable sources of data on age ratios be-
cause of irregular occurrence and site lim-
itations. However, advantage should be
taken of such occasions for the purpose of
obtaining supplementary age data and for
investigating the extent to which disease
may be selective for age classes.
Seasonal Variations in Age Ratios
Because adults and juveniles, like drakes
and hens, have different migration sched-
ules, age ratios calculated for any given
area have seasonal variations.
Differential migratory movements of
adult and juvenile age groups often orig-
inate on the breeding grounds, where most
of the adult drakes of most species leave
their mates early in the nesting period to
congregate on large lakes and marshes;
these areas may be in the immediate breed-
ing area or up to hundreds of miles dis-
tant. After the broods become independ-
ent, the hens leave them and molt their
flight feathers but usually remain in the
area where they nested (Hochbaum 1944:
119, 122). Hens that have been unsuc-
cessful in their nesting efforts may join
the drakes on the lakes or marshes, where
they molt.
Certain large lakes and marshes on the
breeding grounds serve ducks as gathering
areas preceding southward migration. One
of these areas is the Delta Marsh at the
south end of Lake Manitoba, Canada.
The number of juveniles per adult among
mallards in hunters’ bags on that marsh
was checked for several weeks in 1946 and
1947, tables 47 and 48. There was a re-
duction in the number of juveniles per
adult from the third week to the fourth
IttiNo1s NATURAL History SurvEY BULLETIN
Vol. 27, Art. Gam
week in September, 1946, followed by a )
gradual increase in the number of juve-
niles per adult until the first week in No-
vember, when a very sharp decrease took
place. There was a marked decrease in the
number of juveniles per adult in the pe-
riod October 20-25, 1947. When the
Table 47—Number of juveniles per adult
among mallards checked in hunters’ bags on
the Delta Marsh, Manitoba, in each of 6 —
weeks in the autumn of 1946.
Numser | PerCent| JUvE-
Periop oF Ducks| Juve- NILES
CHECKED NILES Per
ADULT
September
3rd week. . 707 67 2.03
4th week. . 146 49 0.96
October
Ist week... 329 54 1
2nd week. . 231 61 1.37
3rd week. . 196 63 1.70
November
Ist week... 33 15 0.18
Table 48.—Number of juveniles per adult ©
among mallards checked in hunters’ bags on
the Delta Marsh, Manitoba, in each of three —
periods in the autumn of 1947.
Numer | Per Cent| JUvE-
PerRIoD or Ducks| Juve- NILES
CHECKED NILES Per
ADULT
OetsiO 35: 121 72 25%
Ocer 13-18 2). 174 71 2.45
Ovt; 20-25... 163 51 1.04
changes in these age ratios were tested sta-
tistically, it was found that in both years
the changes were significant at the 99 per —
cent level (1946, X?=55.04, 5 d.f.; 1947,
2=19.34, 2 d.f.).
a |
~*~
com
A late hatch. sometimes as a result off es
delay in initial nesting and sometimes as _
a result of severe losses of early nests, may
delay the appearance of juvenile mallards —
in Illinois, as in 1939, 1943, 1945, 1947,
1949, and 1950, fig. 12. The effect of am
late hatch may be shown in the degree —
of retention of juvenile plumage by young —
during the southward migration, as was —
evident in juvenile mallards in Illinois in ~
1950 and 1953. Breeding grounds surveys
indicated a delayed or extended hatch in
1950 (Hawkins 1950:42
; Sowls 1950:—
August, 1961
CUMULATIVE PER CENT
1942 1943
0
1939
1940 1941
BELLROSE et al.: SEX RATIOS AND AGE RaTIos
1944
441
1945 1946 1947 1948 1949 1950
Fig. 12.—Year-to-year variations in the seasonal migration of juvenile mallards through
the Illinois River valley, 1939-1950, as shown by the proportion of each year’s juvenile flight
that was in the valley in each of 6 weeks in autumn.
60) and in 1953 (Lynch & Gollop 1954:
47; Gollop 1954:67; Hawkins 1954:77).
That the age composition of the mal-
lard population in Illinois varied from
week to week in the fall is shown by
checks of hunters’ bags, table 44. In any
one year, pronounced week-to-week vari-
ations in the age composition of mallards
taken by hunters in Illinois suggest that
there may be many migratory movements,
some scarcely detectable, within a local
population.
The adult-juvenile composition of the
mallard flight in Illinois for the period
1939-1949 is reflected in fig. 13. Gen-
erally, juveniles made up a greater part
of the mallard bag early in the season than
later. The juvenile proportion in hunters’
bags soon declined, as indicated by data
collected during the first half of Novem-
ber; it recovered somewhat during the
second half of November but declined
again during the first 2 weeks of Decem-
ber. The decline in December resulted as
juveniles moved farther south and large
numbers of adults moved into Illinois from
the north.
In 6 of 7 years, juvenile mallards in
Arkansas formed a greater proportion of
the hunters’ bags in the second than in the
first of two periods during which data
were collected, table 49. The findings
shown in fig. 13 and tables 49 and 50
suggest that, between the mid-flyway areas
(Illinois) and the wintering grounds
(Arkansas), juveniles may be more prone
to leisurely migration than adults.
The daily change in age composition of
the mallard bag at Stuttgart, Arkansas,
for December 2-11, 1950, is given in ta-
ble 50. A marked change in the relative
number of juveniles in the bag occurred
on December 8. A large southward flight
of mallards from Illinois on December 7,
as a result of zero weather and snow, con-
tained a relatively large number of juve-
100
ke
z
uJ
oO
x
WW
ra
15-31 I-15 16-30 I=15
OCTOBER NOVEMBER DECEMBER
Fig. 13.—Juvenile-adult composition of the
autumn flight of mallards in Illinois, as indi-
cated by checks of hunters’ bags in the autumns
of 1939-1949,
442
Ittinois NaturAL History Survey BULLETIN
Vol. 27, Art. 6
Table 49.—Number of juveniles per adult among mallards checked in hunters’ bags at j ;
Stuttgart, Arkansas, in 12 hunting seasons.
| NuMBER
PERIOD OF
HunTING SEASON Siena | (enn:
1946-25. 8a ey Bee Nov. 23-26 1,889
Nov. 27- 1,461
Dec. 1
LOS fete caper Dec. 8-11 2,064
Dec. 12-14 L250
1948 rs ee ee Nov. 26-31 2,035
Dec. 2-4 965
If be Iara ee a are Nov. 18-21 1,830
Dec. 26-27 274
TOS Os eer Shs ee Dec. 2-11 Sele
Dec. 28-29 149
LOS seamen Nov. 22-23 500
Deco 1-3 2,500
EOSD Foe cera Oe See Dec. 6-9 997
LOS SoM ee, Lee aoe Nov. 27-28 341
Dec. 21-22 230
1954-554 Ree Jan. 4-5 408
1955-56. . Jan. 7-8 458
LOS 8 )isce cee ee Dec. 8-10 L139
LOS Oras nt E Nov. 30- 1,053
Dec. 1
nile ducks. Its impact on age ratios in
Arkansas seemed apparent. When age ra-
tios before and after the influx of the
juvenile mallards from Illinois into Ar-
kansas were statistically compared, the
difference was found to be significant
(X?=45.6, 1 d.f.) at the 99 per cent level.
Because Utah is a breeding ground for
several species of ducks, an important
molting area for several species, and an
important migration area for many spe-
cies, it might be anticipated that age ra-
tios in this state would show a complex
relationship to migration.
Records on ducks taken in traps at Og-
den Bay, Utah (Fuller & Low 1951 :42),
indicated that “the earlier arrivals were
immature birds, adults showing up more
frequently from the last of August, .. .”
This evidence from trapping operations
late in summer plus declining numbers of
juvenile pintails during the fall in the
bags of Utah hunters, fig. 14, suggest the
possibility of a pronounced movement of
juvenile pintails through Utah before the
hunting season. According to J. B. Gollop
of the Canadian Wildlife Service (per-
sonal communication), there was good
PROBABILITY
Per Cent Juvenices | THatT CHANGE
JuvENILES Per ADuLT RESULTED :
From CHance ~
ae) 1.22 <0.05>0.025
52 1.08 4
59 1.44 <0.005
67 2.03
68 oa) <0.10>0.05
71 2.45 -*
47 0.89 <0.05>0.10
51 1.04 1
42 0.72 <0.50>0.25
46 0.85 a
59 1.44 <0.05>0.025 a8
64 1.78 ee
65 1.86 1.0, 2)
43 0.74 <0.50>0.25
48 0.92
49 0.96. |. .5:.s.0—n
58 1.38. - |v.. 0 os
32 0.47 as
23 0.29 |...
evidence in Saskatchewan in 1952 that a —
mass exodus of juvenile pintails occurred —
during late August. ee:
A tally of adult and juvenile ducks that —
were victims of botulism during August
and the first half of September, 1952, on
the Bear River Migratory Bird Refuge,
table 46, also provides data on the age
Table 50.—Number of juveniles per adult
among mallards checked in hunters’ bags at
Stuttgart, Arkansas, in each of 10 days in De-
cember, 1950. %
Numper | Per Cent| JUvE-
DaTE or Ducks| Juve- | NILES
CHECKED NILES PER
ADULT
Degie 2:2 535 39.6 0.66
ce 771 soso 0.64
ae 584 38.2 0.62
Ee 345 J35 0.50
Ges 59 32.2 0.48
fee 100 38.0 0.61
ae 240 58.3 1.41
Lt 372 46.5 0.87
£0 469 48.0 0.92
11 237 47.3 0.893
Dec, 2=11 5 ....\ 735712 42.0 0.72 %
August, 1961
ratios of ducks in a Utah area before the
hunting season. These data, unlike the
data from ducks trapped at Ogden Bay,
do not show a large juvenile duck popu-
lation prior to the hunting season. Per-
haps adults are more susceptible to botu-
lism than juveniles, or perhaps there were
differences in age composition between
the duck populations on these two marshes,
which are about 25 miles apart. Such dif-
ferences were reflected in hunters’ bags
checked on the two marshes, tables 55, 56,
and 57. Further study of the composition
of Utah duck populations seems very de-
sirable, because of the differences in age
ratios and the importance of seasonal in-
fluences on age ratios in that state.
Mallard migration in Utah in six au-
tumns of the 1940’s, fig. 14, was some-
what similar to that in Illinois, fig. 13.
Juveniles were most abundant early in the
BELLROSE et al.: SEX RATIOS AND AGE Ratios
443
season; their proportion in the bag stead-
ily decreased to the November 16-30 pe-
riod, after which it remained fairly con-
stant. In Utah, the age pattern of mi-
grating pintails tended to reflect that of
migrating mallards, fig. 14. The green-
winged teal showed a rather steady de-
crease in the relative number of juveniles
as the season progressed, while the shov-
eler had a ratio of adults to juveniles that
remained about the same throughout the
season.
Thus, in the selection of strategic sites
for collecting age data on ducks, and in
the evaluation of age ratios, migration
schedules of waterfowl must be consid-
ered. In some species, much of the migra-
tion occurs outside of the hunting season;
in such species, age ratios calculated from
data collected from hunters’ bags may not
be representative of the populations. Un-
| 100 e. 100 mo
75 75}
: = |
WwW W .
S 50 © 50
jeg a
lJ W
a a
25 25
fe) fe)
100 100
75 75
5 =
W WJ
Oo 505 © 50
jaa a
a a
25 25
fe) )
5-31 I-15 16-30 I-15 —s: 15-31 I-15 16-30 I-15
OCTOBER NOVEMBER DECEMBER OCTOBER NOVEMBER DECEMBER
Fig. 14.—Juvenile-adult composition of the autumn flights of mallards, green-winged teals,
pintails, and shovelers in Utah, as indicated by checks of hunters’ bags in the autumns of 1943,
1944, and 1946-1949,
444
less traps are operated effectively through-
out the period of migration, they, too, will
provide biased data.
Age ratios obtained from mallards while
on their wintering grounds undoubtedly
are relatively unbiased by seasonal move-
ments. It should not be assumed that a
similar statement would be true for all
species. For example, in the pintail, birds
of the two sexes and ages tend to flock sep-
arately in winter, and shifting of these
flocks along the Texas coast is common.
Regional Variations in Age Ratios
Regional variations in the age ratios of
ducks first became apparent to the writers
when data on the ducks checked in hunt-
ers’ bags in Utah, Texas, and Illinois dur-
ing the fall of 1943 were compared. Since
that time, data which provide for further
evaluation of regional differences in age
ratios have become available, tables 51-57.
Mallards.—The juvenile percentage
in mallards checked in hunters’ bags in
I~ttinois NaTturRAL History SurveEY BULLETIN
Vol. 27, Art. 6
each of eight areas of the Mississippi Fly-
way is shown in fig. 15. Juveniles made
up a large proportion of the ducks that
were taken in Manitoba because the adult
drakes tend to migrate from there early,
and the juveniles are more vulnerable to
shooting early in the hunting season than
at any other time. It is not known why
the juvenile proportion of the mallards
taken by hunters in Ohio (the marshes at
Sandusky Bay) was so much greater than
that taken by hunters in Michigan (the
Pointe Mouillee Marsh, which is less than
50 miles from Sandusky Bay).
The progressive north to south de-
crease in the juvenile proportion of the
mallard population, as shown by checks of
hunters’ bags in Manitoba, the Upper
Mississippi areas, the Illinois River valley
areas, and the Arkansas areas, table 51 and
fig. 15, reflects both a progressive decline
in the juvenile population and a decline in
vulnerability to hunting as a consequence
of increasing wariness among juveniles.
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5 5 ¢€ d LX % rs oS rx OY
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% “4 S CJ % 1% S re ¥
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b> ., of S > — Ke Oe XY Rs
“ “ i So Od i IS S
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50 ROO RLS POO OOOF 0000.04 We1e:6.8:
Fig. 15.—Juvenile percentage in mallards checked in hunters’ bags in each of eight areas
of the Mississippi Flyway, 1946-1949.
August, 1961
One question of concern to students of
age ratios is: “Can age ratios at any one
place be used to indicate yearly changes in
production?” ‘Table 51 and fig. 16 show
the yearly trends in the juvenile propor-
tion of the mallard population in a num-
ber of areas. Bag checks in Manitoba are
in general agreement with those in the
Mississippi River basin areas in showing
increases in the juvenile component in
Table 51.—Number of juveniles per adult
regions of North America, 1946-1949.
BELLROSE et al.: SEX RaTIos AND AGE RATIOS
445
1947 and 1948 and a decrease in 1949.
Year-to-year differences in the time of de-
parture of adults and juveniles from the
breeding grounds probably explain some
of the differences between mallard age ra-
tios taken in Manitoba and those taken in
the Mississippi River basin areas.
Year-to-year changes in the juvenile
proportion of the mallard populations of
the Great Lakes areas—principally the
among mallards checked in hunters’ bags in 13
1946 1947 1948 1949 1946-1949
REGION wud os ud os uu os POV ac) os wus os
224] 5< |e24| $< [e24)| = |E2| s= leee| =
5 CO} eH |g eo) ee |S eC) ee |g Ol ee |g le asst
FROME (230 lee, (260) oe las ee ta soles
Messe Manitoba. «.+...<\onies-4-<+ 0 (1 Va ep lee 1,537] 8.80] 2,569] 10.63
Netley, Manitoba..........|......|...... 903) 4.17| 1,248| 5.71] 893] 2.92| 33044} 4.29
Welta, Manitoba........... 1,874| 1.46 496} 1.70 DE e cota eee es ale = eee 2,621) 1.62
Upper Mississippi River. ... A929 653) 2272 eleO2 S200 2351) 5 O593)e2)570 |p 2elS
WISCONSIN coc. cece s cauenws 333) 3.44 287 3295 AO SoG Wot ile ey) Si, Mell] S's
IMENT SAM ee ips oe crsiecrece oes « STAN) OXSS 212| 1.08 Ble Les PROM ists) ifs 1 500)
OUNIGig Aceh ae 993| 4.84 940} 3.22 819} 6.04 735| 2.62) 3,487); 3.90
Micltan ae Thal scene cis terele ate etckee sd kee 369) 0.86 GIT LS L046 e077,
Illinois River valley........ Me SPAY GPS) S14) 2-36) 15215) 38 SOTO. 97)\ 3 943\ ele
IMIS SOE eke cei Sid oe adie ism des SLi ee 518} 1.76 408} 2.92) 1,094) 1.04) 2,347) 1.48
ANAK RCIG Sie Bi o5.0 lel lS Oo l/ | eel OS! So O00ls 2.22/02, LOL On Siilie/ 7il|iealeAs
eee Sb RS, 2,514} 1.88] 1,749] 1.81| 1,252] 0.99] 57515] 1.60
"hohe Gee 853| 1.16] 2,067| 0.66| 1,216] 0.74] 1,062] 0.88] 5,198] 0.78
Table 52.—Number of juveniles per adult among mallards checked in hunters’ bags in
Manitoba, Illinois, and Arkansas, 1946-1955 and 1959.
NuMBER OF JUVENILES PER ADULT anne cow eee
YEAR ee
Manitoba eee ee Arkansas Manitoba Illinois and
(Delta) Valley) (Stuttgart) and Illinois Arkansas
| A sa 1.46 1.25 Tele 0.21 0.09
Meee sees. s cis x2 1.70 2.36 1.63 0.66* 0.73
DES eo aera ye S218 Qe22 1.94 0.96
“iD Sige eae |e eee ee 0597 O2OL. ~*~ eneee. eee 0.06
Re Prarie ess sis swiss > = A WETS oh MISS seed 0.80
7S GG Ete eee yt Lise ee ahah sate car cit tae 0.00*
EMT iA tcp ais Bilictevaieaic ise siete ase 1.65 er Cope En cmtre ee reece ee 0.21*
oF ooS DOE Gee eee 1.48 OT ee oy nea a ng oe 0.66
ere 1.62 0.91 1.04 0.71 L137
SPEAR a, = 5 icc hatet alles cis caidia sks» 1.78 Tyee 10 ga leek eS eer oa 0.38
ee erika 2 isc'k el = 0.78 0.34 0.29 0.44 0.05
BNDTATEIES AAO OG OD 2.14f Hoop HO 25a 0.53 0.31
*Only in 1947 did Illinois exceed Manitoba in number of juveniles per adult; only in 1951, 1952, and 1954 did
Illinois fail to exceed Arkansas in number of juveniles per adult.
+For years in which data were available for both Manitoba and Illinois.
tFor years in which data were available for both Illinois and Arkansas.
446
Horicon Marsh in Wisconsin, the Pointe
Mouillee Marsh in Michigan, the marshes
at Sandusky Bay in Ohio—show little cor-
relation with changes in the Mississippi
River basin areas, fig. 16. However, the
Great Lakes areas are frequented by only
a small proportion of the mallard popula-
tion of the Mississippi Flyway ; these areas
are to the east of the principal routes used
by mallards migrating between their
breeding and wintering areas.
There was reasonably close agreement
in the year-to-year fluctuations in the num-
ber of juvenile mallards per adult in hunt-
ers’ bags in the Mississippi River basin
areas: the Upper Mississippi River, the
Illinois River valley, and the Stuttgart,
Arkansas, area, table 51 and fig. 16. There
was a highly significant relationship be-
tween the age ratios of mallards bagged in
the Upper Mississippi River area, Illinois
River valley, Missouri, and Arkansas dur-
ing the period 1946-1949, table 51, as
demonstrated by a correlation coefficient
of r=+0.969 or higher, which indicated
that the probability that the correlation
was due to chance was less than 0.01.
The age ratios for mallards bagged in
the Illinois River valley were close to
those for mallards taken in the Stuttgart,
100
90
80
we)
Fr
860
=50
MISSISSIPPI BASIN
AREAS
~
~ =_
+ 80 =< >~ Ohio
~
6 70 “LWisconsin
x 6O ss Michigan <3,
WwW Bl a
1946 1947 1948 1949
I_ttinois NATURAL History SURVEY BULLETIN
1950
Vol. 27, Art. 6
Arkansas, area in all but 2 (1950 and
1953) of 11 years (1946-1955 and 1959),
table 52 and fig. 16. The lack of agree-
ment in the age ratios from the two areas
in 1950 and 1953 is believed to have been
related to a delayed hatch on the breeding
grounds followed by a somewhat delayed
movement of juveniles to Illinois, where
a high kill of these young birds occurred.
In 1950, mild weather induced large
numbers of mallards to remain on the
breeding grounds until November 7, when
a severe cold front resulted in an unusu-
ally large exodus. The ducks moved rap-
idly down the flyway, and the adults
passed through Illinois without stopping
so long as is customary. Because of the
unusually rapid movement from the breed-
ing grounds to the heavily shot mid-flyway
areas, juvenile mallards had not been
much exposed to hunting by the time they
arrived in Illinois and, thus, were more
vulnerable to hunting than in most other
years.
Fluoroscopy of live-trapped ducks in
1953, in revealing an unusually low per-
centage of juveniles with shot wounds, in-
dicated that the young of that year, like
those of 1950, had not been much exposed
to hunting before their arrival in Illinois.
MANITOBA MARSH
AREAS
Ao ee
Arkansas
I i sa
GREAT LAKES BASIN
AREAS
1955
1954
1951 952 I953
Fig. 16.—Year-to-year changes in the juvenile percentage in mallards checked in hunters’
bags in each of several areas of North America, 1946-1955.
ON
August, 1961
BELLROSE et al.: SEX RATIOS AND AGE RaTIOS
447
Table 53.—Number of juveniles per adult in five species of ducks checked in hunters’
bags in seven regions of North America, 1948.
Brack Duck PINTAIL BALDPATE REDHEAD LESSER
ScaupP
REcIon ges | 87s ao} aa 0 | as malas ars
SO|/mo| eo|seg| oe / 4g) sg / ss oo | =a
= acs 2 > 5 z
ZO Nee eo eee | bene | ete pee | alee
_ LERRODE A 8 Sela 5 re ire eae 145 | 4.88 S13) ley) 388 |24.00 275 Oe 59
SGC A 208 | 3.35 248 | 4.66 547 |10.11 DAD AGE 296 Daly
SUNG ETO SNe ee 374 | 1.08 102 | 0.96 191 | 3.00 £5) | 5 740) ele, 3.76
aN Da, 4 6 ye 419 | 3.54 258 | 6.14 DDI AD Gi ea a ne eae
“GIN so oes eee SMe Titles Meola ton elle he Sola See ete We. Pe Celie le MERE &
Illinois River valley........ SS paleo efile) Om (Nese) Sunless cee cc | (cae elle eye saed| ae we |W
“GLB. ood 65 pete es eee ee ee PINKY || WaT) ine | Oss) DOGASE7 Oo Ie ese tee
The lack of hunting experience by juve-
niles before reaching Illinois in 1950 and
1953, plus the abnormally rapid flight of
adults through Illinois in 1950, resulted
in the unusually large differences between
Illinois and Arkansas in the number of
juveniles per adult in the mallard bag in
those years, table 52.
With infrequent exceptions, such as
those in 1950 and 1953, it appears that
age ratios taken along the main stem of
the Mississippi Flyway from Delta, Mani-
toba, to Stuttgart, Arkansas, provide an
index to the yearly productivity of the
mallard in the flyway.
Other Species.— Considerable _ re-
gional variation in the number of juveniles
per adult was found in 1948 for each of
five species of ducks checked in hunters’
bags in Manitoba, states of the Mississippi
Flyway, and Utah, table 53. Two of the
four species checked in Manitoba had
more juveniles per adult in that province
than in other localities.
Regional variations in age ratios among
the several species and within any given
Table 54.—Number of juveniles per adult
among mallards checked in hunters’ bags in
two regions of the Illinois River valley, 1939.
Numser | Per Cent Juve-
REGION or Ducks| Juve- NEES
CHECKED NILES PER
ADULT
Wpper..... 1,203 60.4 a2
Lower 1,058 od 1.36
species probably result in part from differ-
ences in seasonal movements among the
species and between juveniles and adults.
It is assumed that regional variations in
age ratios derived from inspection of hunt-
ers’ bags would be most pronounced in
those species of ducks that depart from the
breeding grounds early in the migration
season. Because the hunting seasons for
the various states do not coincide and be-
cause the migration schedules of adults
and juveniles of a given species may differ,
adults of a species may receive greater
hunting pressure in one state, juveniles in
another.
In an unpublished report for 1954,
Milton W. Weller, then of the Univer-
sity of Missouri, pointed out the diverse
movements of the two redhead age classes
in Manitoba. Many adult redheads moved
northward to molting areas following the
breeding season, while most juveniles re-
mained on breeding areas. “he redhead
bag in the molting areas showed a low
juvenile percentage, whereas the bag in the
breeding areas showed a high juvenile per-
centage. Weller speculated that differ-
ences in the migration schedules of adults
and juveniles might influence bag data all
along the migration routes.
The juvenile component in the popula-
tion of each duck species investigated has
tended to be so low in Utah, tables 53 and
55, as to warrant special attention. The
marshes around Great Salt Lake have
long been the scene of unusually heavy
concentrations of early-migrating water-
fowl. As census records showed, peaks in
448
waterfowl populations at the Bear River
Migratory Bird Refuge in 1946, 1947,
and 1948 occurred before the season
opened (Van Den Akker & Wilson 1951:
373). Because juveniles in hunters’ bags
decreased proportionately as the hunting
season progressed, fig. 14, the possibility
is raised that flights which are top-heavy
in juveniles may leave Utah before the
hunting season opens. If this assumption
is substantiated in subsequent investiga-
tions, it would partially account for the
I_ttino1is NaturAL History SurvEY BULLETIN
Vol. 27, Art. 6
abnormally large number of adults in the
bags of Utah hunters.
No doubt some differences between the
age ratios representing various bag inspec-
tion stations have resulted from differ-
ences in the character and size of areas —
sampled. In some cases, age ratio data
representing a checking station may be
from only a single, relatively small area,
such as the Delta Marsh or Netley Marsh
in Manitoba. In other cases, the data may
be from many marshes representing many
Table 55.—Number of juveniles per adult in five species of ducks checked in hunters’ bags
in two areas adjacent to the Great Salt Lake, Utah, in 1947.
NumsBer or Ducks CHECKED
SPECIES
ins Ogden Farmington
Bay Bay
Mallardey acc an:- 677 373
Gadwall. took bs 398 276
Baldpate:230.5.0225¢ 422 276
Pintalicy ass 1,374 1,281
Green-winged teal. . TBH 446
Shoveler;....... 0: 419 357
Juvenites Per Aputt PROBABILITY _
THAT
Ogden Farmington pt Due au
pe Bay CHANCE
0.68 1.01 <0.005
2.36 0.85 <0.0005
3.70 1.76 <0.0005
DS 0.75 <0.0005
1.62 2.09 <0.025
2.19 3.01 <0.005
<3"
Table 56—Number of juveniles per adult in six species of ducks checked in hunters’ bags
in two areas adjacent to the Great Salt Lake, Utah, in 1948.
NuMBER OF Ducks CHECKED
SPECIES
Ogden Farmington
Bay Bay
Mallard: einen. 817 247
Gadwallccaa.-7 429 205
Baldpate 3 whee is 1,142 320
Pinta geen aoe 2,210 761
Green-winged teal... 1,069 395
Shaveler5s once es 687 386
JuvenrtLes Per ADULT ProsABilree
THAT
Ogden Farmington ss i Bo,
Bay Bay CHANCE
0.88 0.77 <0.20>0.10
1.01 1.20 <0.40>0.30
2.30 2.44 <0.90>0.80
0.78 0.64 <0.0005
0.88 0.78 <0.30>0.20
2.06 1.96
<0.80>0.70
Table 57.—Number of juveniles per adult in six species of ducks checked in hunters’ bags
in two areas adjacent to the Great Salt Lake, Utah, in 1949.
NumBer Or Ducks CHECKED Juvenites Per ADULT PRoBaBILITY |
; Sad = THaT
SPECIES Ogden Farmington Ogden Farmington ce a a
Bay Bay Bay Bay Crane
Wallendsedenan Pee 541 380 0.66 0.87 <0.05 ae
Gadwalli ck occ 1,153 322 0.48 0.85 <0.0005
Baldpate. 3). ..4:73- 296 334 3.00 0.90 <0.0005,
Bintatlieasmeen cn 3: 2,027 871 0.51 0.54 <0.50>0.40
Green-winged teal. . 13.212 567 0.52 0.77 <0.0005 _
Shoveler’y cima se 555: 614 1.04 1312 <0.60>0.5
oy
4
August, 1961
acres. For example, mallards checked at
Stuttgart, Arkansas, were shot on at least
20 different swamp or reservoir tracts scat-
tered over an area having a 25-mile radius.
Most of the mallards checked in the IIli-
nois River valley were bagged at 10 clubs
distributed over a linear distance of 100
miles.
Only a slight difference in the number
of juvenile mallards per adult between
populations of the upper and lower sec-
tions of the Illinois River valley was
found in 1939, table 54. This difference
was not significant at the 90 per cent level
mae — 1.79) 1 d.f.).
Much greater differences in number of
juveniles per adult for several species of
ducks were found between populations of
two marshes 25 miles apart and adjacent
to the Great Salt Lake, Utah, in 1947-
1949, tables 55-57. The probability that
the differences were the result of chance
is shown in tables 55-57. There was a sta-
tistically significant difference between
age ratios in the two areas in 11 of 18
meLESLS.
JUVENILES PER ADULT
‘These data suggest that the age compo-
sition of migrating flocks differs and that
fortuitous circumstances result in flocks
especially numerous in birds of one age
1939 = 194 1943 1945 1947
BELLROSE et al.: SEX Ratios AND AGE RATIOS
449
class or the other in a particular marsh.
Where only one waterfowl area in a re-
gion has been sampled, as Winous Point
in Ohio or Pointe Mouillee in Michigan,
the age ratios derived may or may not
reflect those for the entire region.
For species other than the mallard, re-
gional data are not adequate to permit
evaluation of the age ratios derived in any
one area. For each of these species, we
have compiled data from as many areas as
possible in the Mississippi Flyway on the
assumption that data for the total flyway
represent the species better than the data
from any one area and reflect year-to-year
changes in the age composition of the pop-
ulation.
Factors Affecting Age Ratios
Age ratios can be used for appraising
the productivity of ducks if the data on
which they are based have been carefully
evaluated as to the effect of seasonal, re-
gional, and shooting biases. Sufficient data
for calculating age ratios corrected for
differences between juveniles and adults
in vulnerability to hunting have been ac-
cumulated for the mallard in the Missis-
sippi Flyway, table 58 and fig 17. Most
of the data used in the table and graph
Uncorrected Data
Corrected Dota
1949 = 1951 1953 1955 1957 1959
Fig. 17.—Uncorrected and corrected numbers of juvenile mallards per adult in bags of
| Mississippi Flyway hunters in each of several years; uncorrected numbers, 1939-1959; corrected
| numbers, which compensate for differences in hunting vulnerability between adults and juveniles,
| 1939-1955. Points on the graph for 1939-1955 are based principally on Illinois data, table 58.
| Points for 1956-1959 are based on data from Missouri, table 59. Because data for 1955 showed
the number of juveniles per adult among Illinois mallards (1.78) to be about 10 per cent less
than the number among Missouri mallards (1.99), the point for each year in the period 1956—-
| 1959 represents a figure that is 10 per cent less than the corresponding figure in table 59.
Vol. 27, Art. 6)
ILtinois NaturAL History SurvEY BULLETIN
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August, 1961
were collected in Illinois, from both IIli-
nois River and Mississippi River areas.
Data from Arkansas were used for 1950
and 1953 because unusual breeding
grounds and migration conditions in those
years had less influence on the migration
in that state than in Il]linois. Data from
Missouri were used for 1956-1958 be-
cause no data were available for Illinois
in those years and because data from both
states for 1955 permitted correction of the
Missouri data. An appraisal of the effect
of seasonal, regional, and hunting bias on
the age ratios calculated for the mallard
in the Mississippi Flyway is given below.
Seasonal Bias.—Age ratios have been
determined for large numbers of popula-
tion samples by inspection of ducks in
hunters’ bags throughout many hunting
seasons in Illinois. Although the Il]linois
hunting seasons have varied as to open-
ing date and length, most of each south-
ward mallard migration has occurred dur-
ing the open season (Bellrose 1944 :346—
50). Inasmuch as sample size was de-
termined partly by hunter success, which
in turn was determined partly by popula-
tion size, the numbers of birds in the
samples were approximately proportional
to the numbers of birds in the populations
sampled. For these reasons, we believe
that in most years there was little, if any,
seasonal bias in the age ratios derived from
checking mallards in hunters’ bags in
Illinois.
Regional Bias.— Unpublished popula-
tion data and records from the recovery
of bands indicate that the largest segments
of the mallard population in the Missis-
sippi Flyway visit the Illinois River val-
ley. The ducks in hunters’ bags have been
examined each year at numerous places
throughout the valley, thereby minimizing
the effect of data obtained from aberrant
local concentrations of particular age
groups. In 1950, an abnormal migration
resulted in relatively large numbers of
adult mallards passing more rapidly than
usual through the Illinois River valley.
In both 1950 and 1953, juvenile mallards
appeared unusually vulnerable to Illinois
hunters. We believe that the duck kill
checked in Arkansas provided the more
valid data for the Mississippi Flyway in
1950 and 1953, and we have used
Arkansas data, derived from table 49, for
BELLROSE et al.: SEX RATIOS AND AGE RATIOS
451
calculating the numbers of mallard juve-
niles per adult for those years. For the
other years included in table 52, the
differences between Il]linois and Arkansas
in number of juveniles per adult were not
so great as to warrant special treatment
of the data.
Hunting Bias.—The year-to-year vari-
ations in the vulnerability figures for mal-
lards, table 39, make it desirable to evalu-
ate the age ratios, or number of juveniles
per adult, derived from inspection of
hunters’ bags.
Most of the band recovery data from
which the ratios of adult to juvenile vul-
nerability were derived, table 39, were
obtained from ducks banded at the Chau-
tauqua National Wildlife Refuge, which
is in the center of the area in which bagged
ducks were sampled for age. Because no
ducks were banded at Chautauqua in 1945
and 1946, in those years banding data
from McGinnis Slough, table 40, were
used, and adjustments, based on several
years of vulnerability rates, were made
for differences between the two stations.
Because the Arkansas kill data for 1950
and 1953, table 49, were believed to be
more valid than the Illinois data, the
numbers of juveniles and adults inspected
in hunters’ bags in Arkansas were chosen
as base figures for these years, table 58.
The 1:1.27 ratio of adult to juvenile
vulnerability for 1950 and 1953, table
58, was assigned rather arbitrarily. As
table 44 indicates, mallard juveniles are
about half as vulnerable to hunting in
December as in November. Illinois data
for several years showed that the dif-
ference between adult and juvenile mal-
lard drakes in vulnerability to hunting
averaged 0.54 (1:1.54 ratio, table 39).
The largest part of the Illinois mallard
kill was in November. In December,
when the birds were in Arkansas, the
difference between the adult and juvenile
kill figures should have averaged about
half of 0.54, or 0.27, and the ratio of
adult to juvenile vulnerability should have
averaged about 1 :1.27.
Table 58 shows for each year in the
period 1939-1955 the ratio of adult to
juvenile vulnerability among banded mal-
lard drakes and the actual (uncorrected )
number of juveniles per adult checked in
hunters’ bags in the Mississippi Flyway,
452
principally Illinois. It is apparent that
the ratio of adult to juvenile vulnerability
has no correlation with the number of
juveniles per adult bagged by hunters.
Table 58 shows also for each year the
number of juveniles per adult and per
adult hen among mallards checked in the
bags of Mississippi Flyway hunters, each
number corrected for the greater vulner-
o 1.8
°
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0.6 0.8 1.0 1.2 1.4
JUVENILES
ability of juveniles. For the period 1939-—
1955, the corrected figure was 0.95 juve-
nile per adult and 2.7 juveniles per adult
hen. These figures probably reflect the
age composition of mallard populations in
the Illinois River valley for the 17-year
period quite well, for inaccuracies in the
yearly vulnerability rates would tend to
cancel each other out over the period.
Trends in the age composition of mal-
lard populations in the Illinois River
valley reflect trends in the age composi-
tion of mallard populations on the breed-
ing grounds prior to the hunting season.
However, population figures obtained in
Illinois do not represent the true age
composition of the populations on the
breeding grounds, because of the compara-
tively greater loss from hunting experi-
enced by the juvenile segment of the
I~tinois NaturAL History Survey BULLETIN
PER ADULT ON BREEDING GROUNDS
Fig. 18.—Numbers of juvenile mallards per adult on the breeding grounds just prior to the
hunting season, as calculated from numbers of juveniles per adult in Illinois during the huntin C4
season; each of the Illinois numbers on which curves A, B, and C are based has been adjusted
to compensate for a greater shooting loss among juveniles than among adults before reaching
Illinois: 4, 2.0 juveniles per adult, B, 2.5 juveniles per adult, and, C, 3.0 juveniles per adult.
Vol. 27, Art. 6
population between the breeding grounds
and Illinois.
Both shrinkage in the juvenile segment
of mallard populations and seasonal de-
clines in the vulnerability rates of the
juveniles are indicated by the progressive-
ly smaller relative numbers of juveniles
in hunters’ bags as the ducks moved down
the flyway from Manitoba to Illinois to
1.6 1.8 2.0 28 ay
Arkansas, table 52. Juvenile mallards are
undoubtedly more vulnerable to hunters
in Manitoba than to hunters in Illinois,
and to hunters in Illinois than to hunters
in Arkansas, as shown by seasonal changes
in vulnerability ratios, table 44.
Shrinkage in the juvenile segment 0
mallard populations between the breeding
grounds and Illinois is indicated not only
by data in table 52 but by rather abstruse
calculations employing band _ recoveries,
mortality rates, and juvenile vulnerability
rates, as discussed below.
An average annual mortality rate for
adult drake mallards in the Mississippi
Flyway of about 40 per cent has been
derived from band recovery data for
drake mallards banded as adults at Lake
Chautauqua, Mason County, Illinois,
1939-1944 (Bellrose & Chase 1950 9).
August, 1961
It seems reasonable to assume that hunt-
ing accounts for about three-fourths of
this average annual mortality and other
causes for one-fourth, or an average an-
nual mortality rate of 30 per cent from
hunting and 10 per cent from other causes.
An analysis of 6,000 indirect (after the
year of banding) recoveries of adult drake
mallards banded at Lake Chautauqua dis-
closed that 47.6 per cent or about one-half
of the recoveries were from points north
of the Illinois River valley. It seems
reasonable to assume further that hunting
results in approximately a 15 per cent
reduction in the numbers of adult mal-
lards before they reach the Illinois River
valley from the breeding grounds.
Data in tables 44 and 47 suggest that
the juveniles are 2 to 3 times as vulner-
able as adults during the early fall season
when in migration from Manitoba _ to
Illinois. If we assume that juveniles are
2.5 times as vulnerable as adults, and that
hunting takes a toll of 15 of each 100
adults before the flights reach Illinois,
then we may say that hunting takes a toll
of 2.5 times as many juveniles or 37.5 of
each 100 juveniles in the same period.
Fig. 18 shows a scale for converting
the age ratios of mallards occurring in
wild populations in the Illinois River
valley to age ratios which would be com-
parable for wild populations on the breed-
ing grounds prior to the hunting season.
Following is an example showing the
method used to determine a point on the
scale, fig. 18, representing the probable
number of juveniles per adult on the
Canadian breeding grounds when 0.6
juvenile per adult has been determined
to exist in mallard populations in Illinois;
the adults are assumed to have been sub-
jected en route to Illinois to a shooting
loss of 15 per 100 and the juveniles to a
shooting loss of 37.5 per 100.
When
A = the number of adults on the breed-
ing grounds per adult in Illinois,
with a presumed 1:0.6 ratio of
adults to juveniles in Illinois,
a =the number of adults to 0.6 juve-
nile in I]linois,
p =the per cent of the adult popula-
tion remaining after a 15 per cent
loss en route to I[Ilinois,
BELLROSE et al.: SEX Ratios AND AGE RATIOS
453
then
eee SP Ale
1
o OE85
the number of adults on the breed-
ing grounds to | adult in Illinois.
When
Y =the number of juveniles per adult
on the breeding grounds, with a
presumed 1:0.6 ratio of adults to
juveniles in Illinois,
y =the number of juveniles to 1 adult
in I1linois,
p =the per cent of the juvenile popu-
lation remaining after a 37.5 per
cent loss en route to Illinois,
then
Ses 0.6
p 0.625
the number of juveniles on the
breeding grounds to 0.6 juvenile
in Illinois.
Y=
= 0.96,
Thus, when there is a ratio of 0.6 juve-
nile per adult in Illinois, the adults have
been subjected to a 15 per cent loss en
route to Illinois, and the juveniles have
been subjected to a shooting loss 2.5 times
as great as that of adults, the ratio on the
breeding grounds is 0.96 young to 1.18
adult, or 0.81 juvenile to 1 adult.
An average of 0.95 juvenile per adult
was calculated for mallard populations in
the Mississippi Flyway, principally Illi-
nois, over a 17-year period, 1939-1955,
table 58. This average takes into account
differences in vulnerability between adults
and juveniles. If juveniles suffered a loss
of 37.5 per cent en route, the calculated
average number of juveniles on the breed-
ing grounds just prior to migration per
0.95 juvenile arriving in Illinois was 1.52
(0.950.625). If adults suffered a loss
of 15 per cent en route, the calculated
average number of adults on the breeding
grounds just prior to migration per adult
arriving in Illinois was 1.18 (1.00.85).
For the 17-year period, the calculated
average number of juveniles per adult on
the breeding grounds just prior to migra-
tion was 1.29 (1.52~1.18).
If the average number of juveniles per
adult in Illinois (0.95) is to the number
of juveniles per hen in Illinois (2.7),
table 58, as the number of juveniles per
adult on the breeding grounds (1.29) is
454
ILLINOIS NATURAL History SURVEY BULLETIN
Vol. 27, Art. 6
Table 59.—Number of juveniles per adult among mallards shot at the Duck Creek Wildlife
Area, Puxico, Missouri, 1955—1959.*
NuMBER
OF
YEAR Ducks
CHECKED
19S Se ioks Ration hone EG ate 5,581
LOS Gack ek eee ee 2,368
NOS No acierete es eae ona toate 478
LOSS. ee a ee vos 581
TSG, hen ea) lie ae 2,064
APPROXIMATE
Per Cent JUVENILES 95 Per Cenr
JUVENILES Per ADULT CoNFIDENCE
Limits
66.6 1.99 1.79-2.19
58.5 1.41 1.37-1.45
54.8 12k 0.87-1.55
aes 0.60 0.47-0.73
32.6 0.48 0.42-0.54
*Data supplied by George Brakhage of the Missouri Conservation Commission.
to the number of juveniles per hen on the
breeding grounds (X), the number of
young per hen on the breeding grounds
can be calculated by solving for X in the
following equation:
0.95 :2.7::1.29:X
2 i
Bag data for the Mississippi Flyway,
principally Illinois, uncorrected for the
greater vulnerability of juveniles to hunt-
ers, showed an average of 1.43 juveniles
per adult over the period 1939-1955,
table 58. This average is greater than
the calculated average number of juvenile
mallards per adult on the _ breeding
grounds just prior to the hunting seasons
(1.29). A higher figure for Illinois than
for the breeding grounds may have re-
sulted because the disproportionate loss
of juveniles before the mallard popula-
tions reached I]linois was more than com-
pensated for by the disproportionate vul-
nerability of juveniles in Illinois.
Age Ratios as Measures of
Production
Many wildlife technicians have assumed
that increases in the number of juvenile
ducks per adult in hunters’ bags reflect
increases in production of young during
the breeding season immediately preceding,
that age ratios can be used as indices of
production, and that curves plotted from
age ratios may be regarded as production
curves.
Year-to-year changes in the age ratios
of mallards in the Mississippi Flyway are
shown in tables 52, 58, and 59 and fig.
17 for 21 years, 1939-1959. The produc-
tion curve plotted from the corrected age
data follows a pattern somewhat similar
to that plotted from the uncorrected age —
data, fig. 17. However, because errors of —
varying magnitude are probably present
in the yearly vulnerability factors used in —
correcting age data, it has been deemed ©
advisable to use uncorrected age data
rather than the corrected data as the better
indices of year-to-year changes in pro-
ductivity. F
The data (uncorrected) on which the —
broken line in fig. 17 is based indicate
that lows occurred in the production of
young mallards in 1941, 1945, 1950, 1953, —
and 1959; highs occurred in 1939, 1943,
1948, 1951, and 1955. This somewhat
rhythmic production trend may be an —
inherent characteristic of waterfowl popu-
lations and may prove to be density de-—
pendent in origin. ;
Significant data for the Mississippi Fly- —
way are lacking on yearly changes in pro-
duction of species other than the mallard.
However, John E. Chattin of the U. 5.
Fish and Wildlife Service has made avail- —
able age ratios of pintails trapped at seven —
banding stations in California, Oregon,
and Nevada from 1949 through 1959.
The relatively large number of juveniles —
among the pintails trapped, particularly in
1951 and 1952, fig. 19, suggests bias in the —
samples, possibly the result of juveniles
entering the traps more readily than
adults. Nevertheless, the variations in trap —
selectivity from year to year are probably
not great enough to produce large errors
in the indices of production. It is believed
that the age ratios obtained from pintails
trapped in the Pacific Flyway probably
provide a fairly reliable picture of the
production trend of the species. A com-
parison of mallard age ratios in the Mis-
sissippi Flyway with pintail age ratios in
August, 1961
the Pacific Flyway for 11 years, 1949-
1959, fig. 19, reveals for most years an
unexpectedly close agreement between the
production trends of the two species.
The extent of agreement in production
trends between the two species is especially
remarkable when differences in distribu-
tion and habits of the species are con-
sidered. The pintails of the Pacific Fly-
way breed largely in the western part
of the northern plains, whereas the mal-
lards of the Mississippi Flyway breed
largely in the eastern part of the northern
plains. Moreover, mallards are more
prone to nest in the Aspen Parklands and
the northern mixed Coniferous Forest
than are pintails, which are for the most
part confined to the grasslands.
Factors responsible for the yearly fluc-
tuations in mallard production appear to
have fairly consistent simultaneous effects
on pintail production. Discovery of this
fact justifies the use of Mississippi Fly-
way mallard age ratios as criteria for eval-
uating the accuracy of breeding ground
surveys and the effect of environmental
conditions on over-all duck production.
Because breeding grounds surveys have
been used in the past to provide most of
the waterfowl production information on
which annual hunting regulations have
been based, and will undoubtedly be used
for a similar purpose in the future, an
appraisal should be made of the validity
of these surveys.
Breeding grounds surveys are affected
by the vastness of the breeding grounds,
shifts in waterfowl populations with
changing water conditions, and difficulty
in finding and counting broods. Age ratios
obtained from ducks bagged on and south
of the breeding grounds provide a means
for evaluating the validity of waterfowl
breeding grounds surveys and in them-
selves serve as measures of production.
We have attempted to appraise the
validity of breeding grounds surveys by
comparing the results of surveys on the
plains of Manitoba and Saskatchewan
with the mallard age ratios obtained
through inspection of hunters’ bags in the
Mississippi Flyway, principally Illinois.
Banding of ducks on the breeding grounds
has demonstrated that most of the Missis-
sipp! Flyway ducks breed in Manitoba
and Saskatchewan.
BELLROSE et al.: SEX RATIOS AND AGE RATIOS
455
The first comprehensive breeding
grounds surveys were made by the U. S.
Fish and Wildlife Service in 1947. In
that year, although the nesting population
was reported “fair” for Saskatchewan as
a whole, brood production was not corres-
pondingly high (Lynch 1948 :33). In the
same year, the duck crop in the pothole
country of Manitoba was considered good,
but the production in other types of nest-
ing area was “moderate to very poor”
JUVENILES PER ADULT
1949 1951
1953 1955 i957 1959
Fig. 19.—Year-to-year changes in the num-
bers of juveniles per adult in two species, the
data derived by two methods in two areas:
pintails trapped in the Pacific Flyway and
mallards checked in hunters’ bags in the Mis-
sissippi Flyway, 1949-1959.
(Hawkins 1948:52). Yet, in 1947, mal-
lard age ratios from the Mississippi Fly-
way showed a pronounced increase in
juveniles over the number in 1946, fig. 17.
A year later, 1948, “good production”
was reported, and “moderate improvement
in the waterfowl output for Manitoba”
was forecast, by Hawkins & Cooch (1948:
97); a small increase in the duck popula-
tion of Saskatchewan was recorded by
Soper (1948:63). Mallard age ratios ob-
tained in the Mississippi Flyway in 1948
showed a further increase in the number
of juveniles per adult to a new peak,
hig. 17.
In 1949, mallard age ratios from the
Mississippi Flyway indicated that a sharp
drop had occurred in the relative number
of young, fig. 17. From the breeding
grounds, Hawkins (1949:64) reported
that, in Manitoba, nest success was well
below that of 1948. Lynch (1949:52) re-
ported a reduced nesting population in
Saskatchewan as a whole, but a successful
456
hatch in the Aspen Parklands, where mal-
lards from the drought-stricken south-
western part of the province had moved
to join the ducks that normally nest in
the Parklands.
In 1950, Mississippi Flyway age ratios
disclosed a further drop in the number of
young mallards per adult, fig. 17. On the
breeding grounds, Hawkins (1950:45)
concluded “that Manitoba produced con-
siderably fewer ducks in 1950 than in
1949.” In Saskatchewan, Colls (1950 :40)
reported “evidence of a lack of, or an un-
successful attempt at, first nesting among
mallards and pintails,”’ and added that by
the end of July there appeared to be no
important attempts at second nesting by
these two species.
In 1951, mallard age ratios derived
from bagged ducks in the flyway indicated
a marked increase in the production of
young, fig. 17. Hawkins, Gollop, & Wel-
lein (1951:49), reporting on other species
as well as the mallard in Manitoba, wrote,
“the juvenile crop probably doubled the
previous year’s.” Colls & Lynch (1951:
40), after observing the success of the
first nesting attempt in Saskatchewan,
wrote that ‘a more than usually success-
ful waterfowl-rearing season” was antici-
pated for the area.
In 1952, the flyway age ratios indicated
a decline in the number of young mallards
per adult. From one Canadian province,
Hawkins & Wellein (1952:64) reported:
“Manitoba’s contribution to the fall flight
of 1952 should be about one-fifth less than
in 1951.” From Saskatchewan, Gollop,
Lynch, & Hyska (1952:37), following a
survey in July, 1952, reported a potential
production ‘almost twice that of last
year.”
A decrease in the production of young
in 1953 was reflected by age ratios for
mallards bagged in the Mississippi Fly-
way and by field observations in the area.
Moderate decreases were reported in
Manitoba by Hawkins (1954:76) and in
> pace by Lynch & Gollop (1954:
49).
Age ratios for mallards bagged in the
Mississippi Flyway showed little change
from 1953 to 1954, fig. 17. For 1954 on
the breeding grounds, predictions made
after a summer census were that the fall
flight of ducks from southern Manitoba
ILLINoIs NATURAL History SurvEY BULLETIN
Vol. 27, Art. 6
would be “about the same as last year,’
but that a “noticeable” reduction would
occur in size of flights from northern —
Manitoba and from both northern and
southern Saskatchewan (Crissey 1954:59,
62.37).
In 1952, John J. Lynch of the U. S.
Fish and Wildlife
mathematical formulas
charts 1 and 2). From the formulas he
1959
1949 =I951 1953 1955 1957
Fig. 20.—Relationship between age ratios of
mallards in autumn and the hatch on the breed- _
ing grounds in the previous spring, as indi-
cated by number of juvenile mallards per adult
in hunters’ bags in the Mississippi Flyway,
principally Illinois, 1949-1959, and forecast
indices of duck production in Canada (Lynch
forecast indices, Gollop, Lynch, & Hyska 1952: _
37), the indices derived from breeding grounds —
surveys in Manitoba, 1953-1959, and Saskatche-
wan, 1951-1959.
derived forecast indices, one as of June 1
and another as of August 1. The August
index was based upon July data: number
of broods per square mile, number (per
square mile) of late-nesting pairs and
single drakes and hens which supposedly
represented late-nesting pairs, number of
ponds per square mile, number of duck- —
lings per class III (almost completely
feathered) brood, and number of class II
(partially feathered) and class III broods —
per square mile. An index rating of 100
was deemed satisfactory; an index rating —
of 300 was deemed perfect. Later, some —
minor modifications were made in the —
formulas.
A mimeographed report, “Waterfowl
Breeding Ground Survey Report, 1958,” —
compiled by Arthur S. Hawkins for the —
U. S. Fish and Wildlife Service, provides —
a comparison of late season forecast in-
dices for Saskatchewan, 1951-1958, and
for Manitoba, 1953-1958. A similar re-
Service developed —
for forecasting —
waterfowl production in Saskatchewan —
(Gollop, Lynch, & Hyska 1952:37 and —
—
250 INDEX, 2.035
= SASKATCHEWAN 5] \ 2
= 4
& 200 1.5 x
x< a
a ”
z 150 Ow
= =
PS Zz
re) \ w
= 100 INDEX, \ 052 |
a MANITOBA 5
,
> =
August, 1961
MILLIONS
a
SOUTHERN
1953 1954 1955
BELLROSE et al.: SEX RATIOS AND AGE Ratios
1956
457
SASKATCHEWAN
S57 1958 1959
Fig. 21.—Estimated numbers of mallards in various parts of the Canadian breeding grounds
in May, 1953-1959.
port compiled by Hawkins in 1959 pro-
vides data on breeding grounds forecasts
for that year. The production forecast
indices for Saskatchewan and Manitoba
may be compared with the number of
juvenile mallards per adult as checked in
the bags of Mississippi Flyway hunters,
fig. 20.
For the period 1952-1959, the popula-
tion curve plotted from the forecast in-
dices of waterfowl production in Saskatch-
ewan was similar to the curve plotted
from the Mississippi Flyway age ratios
for mallards, fig. 20. However, for the
years 1955 through 1958, and especially
for 1958, the forecast indices showed con-
siderably higher production than was
shown by the age ratios, fig. 20.
Manitoba forecast indices showed very
little correlation with mallard age ratios
from the Mississippi Flyway, fig. 20. For
example, in 1957 and 1958, Manitoba
forecast indices pointed to an increasing
production of young; yet the mallard age
ratios from the Mississippi Flyway pointed
to a decreasing production of young. That
there is only slight correlation may be
ascribed to Manitoba’s relatively small
contribution of mallards to Illinois and
adjoining states. Aerial surveys made on
the breeding grounds in May indicate that
about six times as many mallards nest in
the plains and parklands of southern
Saskatchewan as in the plains and park-
lands of southern Manitoba, fig. 21; the
Saskatchewan contribution to the Missis-
sippi Flyway kill is larger than that of
Manitoba, even though much larger num-
bers of Saskatchewan mallards than of
Manitoba mallards are killed in the
Central and Pacific flyways (Cartwright
1956:14—5, 17—8, 20-1).
For 8 years, beginning with 1952,
Saskatchewan breeding grounds indices
showed production trends similar to those
derived from mallards shot by hunters in
the Mississippi Flyway, fig. 20. Informa-
tion on breeding grounds success of ducks
in Saskatchewan in 1951 was somewhat
contradictory. The report by Colls &
Lynch (1951:40) indicated “a more than
usually successful waterfowl-rearing sea-
son.” The forecast index for 1951, al-
though above 100 and therefore “‘satis-
factory,” indicated a production that was
low compared to that of most other years
of the period 1949-1959. We are in-
clined to believe that some mechanical
error was made in calculating the 1951
forecast index for Saskatchewan.
During the period 1949-1954, duck
production as determined from breeding
grounds surveys in Manitoba showed a
fairly close relationship to production as
458
determined from age ratios of mallards
shot in the Mississippi Flyway, principally
Illinois. However, production as deter-
mined by the forecast index in Manitoba
showed no positive correlation with pro-
duction as indicated by age ratios of ducks
shot in the Mississippi Flyway; dia-
metrically opposite production trends were
indicated for 1954, 1955, 1957, and 1958,
fig. 20. The mallard flight reaching IIli-
nois from Manitoba, compared to that
from Saskatchewan, may have been so
small as to have had little influence on age
ratio figures obtained from mallards in-
spected in hunters’ bags in the Missis-
sippi Flyway.
One item apparently responsible for bias
in the forecast index, especially in Mani-
toba, has been the production factor asso-
ciated with late-nesting ducks. This factor
was included in the index formula to
measure the anticipated brood production
represented by pairs, lone hens, and lone
drakes (believed to be mates of incubating
hens) found on the last survey flights,
usually conducted in mid-July. The pro-
duction from ducks that are actually
breeders may be lower than anticipated,
and many ducks that are classed as
breeders may be through breeding. Charles
D. Evans of the U. S. Fish and Wildlife
Service and Ralph Hancox of the Mani-
toba Game Branch recognized the latter
possibility in Manitoba in 1958 (unpub-
lished report), when they found abnormal-
ly high numbers of molters and premolters
on breeding areas. In spite of diligent
effort to classify breeders and nonbreeders
correctly, Evans and Hancox believed that
they included many nonbreeders in their
late-nesting index.
It is apparent from age ratio data from
the Mississippi Flyway that in those years
in which there was a major population
shift from the Canadian Grasslands north
to the lakes and marshes of the Aspen
Parklands and Mixed Coniferous Forest
production of young declined more than
had been anticipated.
No doubt some of the differences be-
tween production data based on age ratios
obtained from bagged ducks in the Missis-
sippi Flyway and similar data based on
breeding grounds surveys stem from dif-
ferences in production between the Grass-
lands, the Parklands, and the Coniferous
ILttinois NATURAL History SurvEY BULLETIN
Vol. 27, Art. 6
Forest region. Because of difficulty of ac-
cess, difficulty in making observations, and
a low density of breeding ducks, only
cursory duck surveys have been made in
the Coniferous Forest region. Hence, the
production of mallards from this region:
is largely unknown but may be larger
than suspected. Although the population
density of mallards there may be low,
this region is so vast that it may well con-
tain a sizable breeding population.
Other differences between production
data from the Mississippi Flyway and
data from the breeding grounds surveys
may result because the Mississippi Flywa
data include only mallards, whereas data
from breeding grounds surveys include
all species of ducks. Mallards usually
make up over half of the breeding popula-
tion, but diving ducks and _ late-nesting
eae such as the baldpate and the gad-
wall, which may show yearly production
trends different from those of the mallard
may influence the production data from
the breeding grounds.
Production and Environment
It is difficult to evaluate the effect of
environment on waterfowl production be-
cause of the vastness of the breeding
grounds and the variations in water and
weather conditions. Seldom, if ever, are
water or weather coudinose similar over
the entire breeding range. Moreover, an
area that is favorable for waterfowl in
one year may be unfavorable the next.
Nevertheless, a general review of water
and weather conditions in Manitoba and
Saskatchewan, the principal breeding
range of the mallard of the Mississippi
Flyway, has been made for the years 1939-
1946 from The Duckological, a news sheet
published at irregular intervals by Ducks
Unlimited (Canada), with headquarters
at Winnipeg, and for the years 1947-1959
from published and unpublished reports of
breeding grounds surveys by the U. 5.
Fish and Wildlife Service and the Canad-
ian Wildlife Service. In the following
paragraphs the water and weather condi-
tions on the breeding grounds for each of
the 21 years in the period 1939-1959 are
summarized in relation to mallard pro-
duction as indicated by the number (un-
corrected) of juveniles per adult inspected
in hunters’ bags in the Mississippi Flyway
August, 1961
—lIllinois and Arkansas, table 58, and
Missouri, table 59.
Water conditions on the Canadian
plains in the spring of 1939 were much
improved over those of 1938. Conditions
for breeding ducks were good in Sas-
katchewan and poor in Manitoba. Most
water areas persisted until broods were
on the wing. These conditions resulted in
a production per breeding mallard (uncor-
rected number of juveniles per adult)
which was about equal to the average of
such production data for 17 years, 1939-
1955, table 58.
In 1940, spring water conditions in
Manitoba were the worst in the history
of that province and in Saskatchewan were
poor as far west as the central part. Water
conditions were good in western Sas-
katchewan. Good rains in June improved
many water areas. Mallard production in
this year, as in 1939, was close to the
average for the 17-year period, table 58.
In the spring of 1941, water conditions,
although greatly improved over conditions
in 1940, were considered fair in Manitoba
and ranged from poor to good in Sas-
-katchewan. Water areas rapidly dried up
when such summer rains as fell failed
'to maintain them. Heavy losses among
ducklings occurred as a result of drought.
: A drop in the number of young per adult
: bagged in the Mississippi Flyway re-
vealed a sizable decline in mallard produc-
tion, table 58.
In the spring of 1942, water conditions
| were fair to good in Manitoba; they were
bad, fair, or good, depending on the
locality, in that part of Saskatchewan
where most of the ducks are produced.
Heavy spring rains prevailed over most
of the plains, and these continued into
the summer. The number of young per
adult in the Mississippi Flyway, table 58,
indicated a moderate increase in mallard
production.
Spring water conditions in 1943
throughout the Canadian plains were the
best in many years, being rated fair over
northern Saskatchewan and_ northern
Manitoba and good to excellent almost
everywhere in the southern parts of these
provinces. In that year, age ratios in the
Mississippi Flyway, table 58, indicated
a pronounced increase in mallard pro-
duction.
BELLROSE et al.: SEX Ratios AND AGE RATIOS
459
In 1944, there was “lots of water” in
northern Saskatchewan and Manitoba, but
in the southern parts of these provinces,
where most of the ducks are produced,
water levels were largely “dangerously
low” to fair. A larger than usual propor-
tion of the breeding waterfowl population
moved through the Grasslands northward
into the Aspen Parklands and Mixed
Coniferous Forest. Rains in June re-
moved danger of heavy loss of ducklings
through drought. Mallard production de-
clined markedly to a point below average,
table 58.
In 1945, spring water conditions were
good in Manitoba and all of Saskatchewan
but the southwestern part, where few
Mississippi Flyway mallards breed. Water
conditions in Manitoba remained good for
ducks, but southern prairies of Saskatche-
wan dried up. Subnormal temperatures
occurred through much of April and May,
and, in the northern portions of Manitoba
and Saskatchewan, ice was still present on
marshes and lakes on May 24. Age ratios
of ducks bagged on the flyway indicated
that mallard production had declined to
the lowest point since the study started in
1939, table 58.
In 1946, water conditions were excel-
lent in Manitoba and through a belt 100
miles wide in eastern Saskatchewan. June
rains improved water conditions in Al-
berta and Saskatchewan. May was ex-
cessively cold, and heavy frosts occurred.
Age ratios from the Mississippi Flyway
indicated that mallard production rose
considerably but remained below the 17-
year average, table 58.
More detailed information on breeding
grounds conditions became available in
1947, when extensive surveys were in-
augurated by the U. S. Fish and Wildlife
Service. Salient facts from these surveys
have been condensed in tables 60 and 61
and are shown graphically in figs. 22 and
23. ‘These tables and figures, as well as
tables 58 and 59, should be referred to in
connection with the following paragraphs
on duck production and breeding grounds
conditions.
In 1947, a year in which fair to good
water conditions prevailed and slight to
moderate water loss occurred during the
breeding season in Manitoba and Saskatch-
ewan, the number of juveniles per adult
Vol. 27, Art.
ILttinois NaTurRAL History SurvEY BULLETIN
460
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in the bags of Illinois hunters revealed a
spectacular rise in production by the mal-
lard ; the rise occurred even though spring
temperatures were below normal. ‘The
spectacular increase in production con-
tinued in 1948, as water conditions in
Canada improved. In 1949, water condi-
tions in Saskatchewan were poor, and
mallard production dropped drastically.
In 1950, water conditions were excel-
lent in both Manitoba and Saskatchewan.
May of 1950, however, was unusually
cold and wet. Mallard production, as in-
dicated by age ratios of ducks bagged
in the Mississippi Flyway, declined. In
1951, water conditions were good through
the breeding season in Saskatchewan and
fair in Manitoba; a major water loss oc-
curred in Manitoba. In that year, mallard
production increased considerably. The
two provinces differed materially in water
conditions in 1952. In Manitoba, rapid
disappearance of water areas began in
April and continued through the summer;
by August waterfowl conditions were the
worst known since breeding grounds ob-
40
32
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1948 1949 1950 1951 1952 1953
MALLARD
BELLROSE et al.: SEX Ratios AND AGE Ratios 461
servations were started. In Saskatchewan,
water conditions were favorable through-
out the breeding season. Mallard produc-
tion in 1952 declined very little, if at all,
age ratios of bagged ducks indicated. In
1953, water conditions were excellent in
Saskatchewan and fair to good in Mani-
toba. There was no water loss during the
season in Manitoba and only a slight loss
in Saskatchewan. Despite these favorable
water conditions, age ratios of bagged
ducks revealed a decline in the production
of mallards in 1953.
Although small water areas in Sas-
katchewan and Manitoba were almost at
maximum numbers in 1954, age ratios
indicated only a slight increase in mallard
production, fig. 22. In 1955, with a
further increase in number of ponds in
Saskatchewan, but with a sizable decrease
in the number in Manitoba, mallard pro-
duction increased materially.
Ponds were down in number in Sas-
katchewan in 1956, but they increased in
number in Manitoba, fig. 22. In that year,
age ratios of bagged ducks indicated a
,. _ MANITOBA
‘\
x PONDS
MALLARD JUVENILES PER ADULT
:
JUVENILES
ie}
1954 1955 1956 1957 1958 1959
Fig. 22.—Relationship between water conditions on the Canadian breeding grounds and
mallard production, as indicated by the number of ponds per square mile in southern Saskatche-
wan and southern Manitoba in May of certain years, and by the number of juveniles per adult
checked in hunters’ bags in the Mississippi Flyway. Points on the graph representing number
of juveniles per adult for 1948-1955 are based principally on data from Illinois, table 58; points
for 1956-1959 are based on data from Missouri, table 59. Because data for 1955 showed the
number of juveniles per adult among Illinois mallards to be about 10 per cent less than the num-
ber among Missouri mallards, each point on the graph for the years 1956-1959 represents a
figure that is 10 per cent less than the corresponding figure in table 59. Data for the breeding
grounds are from the U. S. Fish and Wildlife Service and the Canadian Wildlife Service.
462
drop in mallard production. In 1957,
ponds were down in number in both
provinces, and mallard production de-
clined. In the following year, 1958, water
areas continued down in number in Mani-
toba but increased in Saskatchewan; mal-
lard production showed a further decline.
In 1959, water conditions in Manitoba
remained about the same as the year be-
fore, but the number of ponds in Saskatch-
ewan declined sharply. For the fourth
consecutive year mallard production de-
25
2.0
JUVENILE MALLARDS PER ADULT
PONDS PER MALLARD AND
ie}
1952 1953 1954
Fig. 23.—Relationship between the density of the adult mallard population on the Canadian —
ILttinois NATURAL History SurvEY BULLETIN
1955
Vol. 27, Art. 6%
mile in May) followed similar trends in
most years of the period 1948-1959, fig.
22. Mallard production and water abun-
dance followed divergent trends in 1950,
1953, and 1958. In 1954, mallard pro-
duction showed no decisive trend, while
water abundance rose markedly. In —
Manitoba, mallard production tended to —
parallel water abundance in the years %
1956-1959 but not in the 3 years previous. _
In 1945, 1950, and 1953, when water
conditions on the breeding grounds were
ee ee a ne
JUVENILES
1959
1957
1956 1958
breeding grounds in spring and the production of young, 1952-1959, as indicated by the number —
of ponds per mallard in southern Manitoba and southern Saskatchewan in May and by the num-—
ber of juveniles per adult checked in hunters’ bags in the Mississippi Flyway the autumn fol- —
lowing. Data for the breeding grounds in 1952 represent Saskatchewan only. Points on the
graph representing number of juveniles per adult for 1952-1955 are based principally on data —
from Illinois, table 58; points for 1956-1959 are based on data from Missouri, table 59, as ex- —
plained in the legend for fig. 22. Data for the breeding grounds are from the U. S. Fish and ©
Wildlife Service and the Canadian Wildlife Service. ¥
clined; the number of juveniles per adult
in the Mississippi Flyway, as represented
by data from Missouri, was at a 21-year
low, tables 58 and 59.
No completely objective correlation can
be made between waterfowl production
and conditions on the breeding grounds.
Much of the information from the breed-
ing grounds is not of an objective nature;
it is not subject to convenient or exact
measurement, and the effects of the many
environmental variables are not well un-
derstood.
In Saskatchewan, mallard production
(as determined by the number of juve-
niles per adult among birds bagged in
Illinois) and water abundance (as meas-
ured by the number of ponds per square
fair to excellent and mallard production
was down, temperatures below normal and ~
other unseasonable weather conditions, in-
cluding blizzards, occurred as late as mid-
May, disrupting the nesting activities of
the mallard, pintail, and other early
nesters. In 1947, when water conditions —
were fair to good, and subnormal temper-
atures were experienced early in the nest-—
ing period, mallard age ratios indicated
substantially better than average produc-
tion.
Concerning weather and water condi-
tions in Manitoba in 1950, Hawkins
(1950:42) reported as follows:
If abundant water were the only require-
ment of nesting waterfowl, ducks nesting in
Manitoba would have had a “banner” year;
August, 1961
they did not, however, in spite of the greatest
spread of surface water in many years.
Sub-normal temperatures continued through-
out the nesting and brooding season. May
was particularly cold and wet, possibly a
factor in the poor hatch. From July 12 to 15,
when many broods were only a few days old,
temperatures dipped almost to the freezing
point, perhaps another factor affecting success.
Colls (1950:36-7) reported that un-
seasonably cold weather prevailed all over
Saskatchewan for most of the summer and
that the more northerly lake country re-
mained ice-bound in some cases as late as
the end of May; however, he stated ‘“‘that
weather and water conditions over south-
ern Saskatchewan were exceptionally
favourable for the 1950 waterfowl popula-
tion.”
Hawkins (1954:75) reported that on
April 15, 1953, the worst spring blizzard
in many years combined with several days
of freezing temperatures to adversely af-
fect waterfowl production in Manitoba.
Another record-breaking blizzard oc-
curred on May 11, and smaller snow-
storms on April 24 and May 14 resulted
in snowdrifts which could have buried
large numbers of nests. Indeed, a few
nests that had been buried were found
after the snow disappeared. Furthermore,
temperatures accompanying the blizzards
were sufficiently low to freeze unprotected
eggs.
In Saskatchewan, Lynch & Gollop
(1954:45) reported that May, 1953, was
very cold, with much snow prior to the
middle of the month. Stoudt & Buller
(1954:55) reported that the weather was
“wet, cold and miserable for the most
part’ during the nesting and brooding
season, but concluded: “We have always
heard of the dire effects of wet, cold
weather on newly hatched ducklings but
such ill effects were not noted during the
1953 brooding season.”
A late breakup of ice occurred in Mani-
toba lakes in 1954 (Evans 1955:72), with
freezing temperatures and snow extending
into early May. May and early June
were generally cool and wet.
Saskatchewan experienced a_ record-
breaking cold wave in late April and
early May of 1954 that substantially de-
layed nesting by mallards and pintails
(Gollop & Lynch 1955:46-7). As late
BELLROSE ef al.: SEx Ratios AND AGE Ratios
463
as mid-May, many lakes were still frozen
over.
As a result of adverse weather in the
spring of 1954, Stoudt & Stinnett (1955:
60) found an extremely high nest loss
among mallards as well as other ducks
on a small study area in southeastern
Saskatchewan. They attributed the loss in
the first nesting effort of mallards to a
blizzard and zero temperature on May
1. Most of May and June was charac-
terized by cold, very wet weather, retard-
ing the development of good nesting cover.
The paucity of nest cover and the lack of
stable food for predators resulted in great-
ly increased predation upon duck nests.
Flooding destroyed many nests missed by
predators.
Decreased production by the mallard
on the plains of Canada in years of very
plentiful water and of cold weather, snow,
and heavy rains at nesting time suggests
that cold and excessively wet springs may
be as unfavorable to duck production as
dry and warm springs.
It is quite evident that water and
weather conditions on the breeding
grounds during the nesting and rearing
period were major factors contributing
to the gross changes in mallard production
in 1939-1959. Yet there was another
factor in mallard production, population
density, that seems to have operated in
most years within the broad limits of the
environment, and, indeed, that may well
have been the dominant regulating factor
in production in those few years in which
there was a poor correlation between en-
vironment and age ratios. In 2 years
having similar water conditions but breed-
ing populations of different sizes, the num-
ber of juveniles produced per breeder may
be lower in the year with the larger popu-
lation than in the year with the smaller.
Several years ago, an inverse relation-
ship between population density and pro-
duction of young was reported for the
muskrat by Errington (1943:877), who
stated: “the data indicate that rates of
increase tend to vary with particular
habitats and inversely with the density of
the breeding stock.”
That an inverse relationship between
population density and production could
be detected in upland game was noted by
several writers (Baskett 1947: 25-7;
464
Bump ef al. 1947:540; Errington 1945:
13).
Production in the mallard and possibly
other duck species may bear, within cer-
tain undetermined limits, an inverse rela-
tionship to population densities, or a direct
relationship to number of ponds per duck.
(Increased density in a duck population
on the breeding grounds may be brought
about by a decrease in the number of water
areas as well as by an increase in the
number of ducks.)
With the exception of 1953 and 1954,
years in which cold temperatures and snow
reduced production of the mallard, there
was a good correlation between number of
ponds per breeding mallard and produc-
tion of young on the Canadian breeding
grounds. As the number of ponds per
breeding mallard decreased from 2.0 to 0.6
in the Grasslands and Aspen Parklands
of Manitoba and Saskatchewan, produc-
tion declined from 1.78 juveniles to 0.54
juvenile per adult, fig. 23.
A change in the density of the mallard
population on the breeding grounds may
affect production in two ways: (1) alter
the rate of nest destruction and desertion;
(2) alter the relative number of ducks
that can be accommodated by prime breed-
ing habitat.
Sowls (1955:74) found that most mal-
lards nest within 100 yards of pond,
slough, or lake margins rather than at
greater distances from water. The area
of nest concentration adjacent to a body
of water has been called the nesting zone.
As ponds and other small water areas
decline in number, greater concentrations
of mallard nests occur in the nesting zones
of the bodies of water that remain. It is
probable that, as nest density increases,
the rate of nest loss rises. Although data
on the relationship between nest density
and nest loss are lacking for waterfowl,
Stokes (1954:36) found that in pheasants
nest abandonment increased with breeding
density.
Unpublished field studies by Alex
Dzubin (letter March 5, 1960) of the
Canadian Wildlife Service suggest that
space requirement also may be related to
mallard production. Dzubin believes that,
through interactions involving both ag-
gressive and sexual behavior, pairs of mal-
lards space themselves over the breeding
ILttinois NATuRAL History Survey BULLETIN
Vol. 27, Art. 6
grounds. Adequate spacing is most evi-
dent in the Aspen Parklands region, with
its abundance of water areas; it is less
evident in the Grasslands region, which
may have a scarcity of water areas. Space
behavior of ducks around waiting areas
tends to place a limit on the number of
pairs any one area can accommodate.
The role of space in regulating the size
of breeding populations of waterfowl is
apparent in an analysis made by Schroeder
(1959:4-5) of water areas and numbers
of breeding ducks in North Dakota.
Schroeder found that the numbers of
breeding ducks and water areas tended to
fluctuate up and down together. For
example, in 1950, water areas numbered
11.4 and breeding ducks 24.6 per square
mile, whereas, in 1959, water areas had
declined to 2.1 per square mile and ducks
to 8.4 per square mile.
Evans & Black (1956:52) found a
direct relationship between water areas
and breeding ducks on an 11.25-square-
mile prairie pothole area in South Dakota.
Their study showed that as the number
of potholes with water on May 10 in-
creased and then decreased from 1950
through 1953 so did the number of breed-
ing pairs of ducks.
Stoudt (1959:103) reported a direct
relationship “up to a certain point” be-
tween numbers of breeding ducks and
numbers of water areas on a study area
40 miles long and one-eighth mile wide
near Redvers, in southeastern Saskatche-
wan. He did not find this direct rela-
tionship in “extremely wet years and
extremely dry years.”
From 1953 through 1958, there were
only small variations in the number of
water areas each year on May 1 in a
Lousana, Alberta, study area, but the
number of breeding pairs of mallards on
this small area rose from 103 to 338 dur-
ing that period (Smith 1959:3, 8). The
number of ponds on May 1 decreased from
198 in 1958 to 131 in 1959 and the num-
ber of breeding pairs from 338 to 241.
The smaller a study area, the less likely
it is to show direct relationships between —
the numbers of breeding pairs and the
numbers of water areas. Local variations —
in mortality rates, homing, and population —
saturation levels that grossly affect the —
data for small areas may have no appreci- —
August, 1961
able effect upon the data for extensive
areas, because the many local variations
in the extensive areas tend to cancel each
other.
Because the space behavior of ducks
limits the number of breeding pairs that
a given waterfowl habitat can accom-
modate, when an increase occurs in the
breeding population of an area that has
reached the limit of its carrying capacity,
or when a decrease occurs in the number
of ponds on the area, some of the ducks
associated with the area must do one of
two things: (1) move to other areas not
occupied to the saturation level or (2)
fail to reproduce.
The areas to which the ducks move may
be of poorer quality for the production
of young than the areas occupied to the
saturation level. Biologists have long been
aware of the tendency of bird populations
to make maximum use of the best available
habitat before occupying less favorable
habitat. On a Saskatchewan study area,
Stoudt (1952:55) found that breeding
pairs of ducks tended to make maximum
use of the small water areas (1 acre or
less) and shift to less favorable habitat
when the prime areas were occupied to the
limit of their carrying capacity.
Under conditions associated with popu-
lation or habitat changes, ducks may move
from a region of basically good habitat to
a region of inferior habitat. In 1959,
there was an increase in the number of
mallards found during May in the marshes
of the Coniferous Forest in northern
Alberta and other northern parts of
Canada and a decrease in the number
found in southern Saskatchewan. The
Coniferous Forest lacks the quality habitat
for nesting mallards supplied primarily
by the Grasslands and secondarily by the
Aspen Parklands.
Biologists have noted that under severe
crowding many ducks do not breed and
that some ducks that make attempts at
nesting do not make further attempts if
the first attempts fail. Arthur S. Hawkins
and Gerald Paspichal in an unpublished
report of the U. S. Fish and Wildlife
Service on the 1959 breeding season in
the pothole country of western Manitoba
noted that many ducks in that area were
individuals that had been displaced from
other areas. They found indications that
BELLROSE et al.: SEX Ratios AND AGE RaTIOs
465
some ducks did not attempt to nest and
that others did not make the usual re-
nesting attempts after having lost nests.
Stoudt (1959:104) observed that many
pairs of ducks in southeastern Saskatche-
wan in 1959, a year of very low water
levels, “did not seem to nest at all.”
Fig. 17 may be interpreted as showing
that when the Grasslands and Aspen Park-
lands have reached the limit of their carry-
ing capacity as a result of population in-
creases and/or habitat deterioration, the
production of juveniles per adult mallard
declines for 2 to 4 years, until the breed-
ing population has declined to a point
where population density is no longer a
limiting factor. Then, when a decrease
in population or an increase in water areas
results in more space per breeding pair,
the production of young per breeder in-
creases for 1 to 3 years, until population
density again becomes a limiting factor.
The highs and lows in a breeding popu-
lation of mallards may lag 1 or 2 years
behind the highs and lows in the produc-
tion of young per breeder. The first year
a high breeding population produces a
smaller number of young per breeder, the
over-all population will probably con-
tinue to increase because of the large
number of breeders still present to produce
young. The over-all population may con-
tinue to increase even into the second year
of lower production. When the breeding
population is at a low point, the over-all
population will probably continue to de-
cline for a year after an increase in pro-
duction, as the increased number of young
per breeder may fail to result in as many
young as are needed to replace the ducks
lost through hunting and natural mortal-
ity the previous year.
The foregoing analysis of the effect of
environment on production of mallards
and other ducks points up the importance
of water areas that are available to breed-
ing pairs. Also, it points to abnormally
low temperatures and associated weather
conditions in April and May as factors
of major importance in production. Ab-
normally low temperature conditions do
not occur on the breeding grounds as
frequently as abnormally low water condi-
tions. Within the framework of accept-
able nesting environment, and within
certain undetermined population limits,
466
ILtinois NaturAL History SurRvVEY BULLETIN
Vol. 27, Art. 6
Table 62.—Number of juveniles per adult hen (the number corrected for the greater vul-
| NuMBER OF J Caspar?
= 3 UVENILE UMBER OF
sreciss | Nowmen or | Newnan or | Jovetiss | vivrenanni: | Juvemues
sri oe iry Factror* Per ADULT
EN
Mallard jcc5..5 sina 3,631 19, 860 5.47 ree 4.2
Black duck.'....... 402 2,858 7g | 1.8 4.0
Gadwalls soso. 201 15335 6.64 2.4 2.8
Baldvates ix ase: cs 210 2,280 10.86 29 327
Pinte. issu ees 445 | 2,669 6.00 1.9 Ro
Green-winged teal. . 226 | 1,427 6.31 1b 3.7
Blue-winged teal. . . 370 | 1,901 5.14 he 7 3.0
Shoveler:. 0. i .s..-: 119 836 / 7.03 1 Wears 4.1
Redhead.......... 190 1,882 9.91 325 2.8
Ring-necked duck. . 123 1,043 / 8.48 2.0 4.2
Canvasback....... 208 | 2,745 13.20 2.9 4.6
Lesser scaup....... 297 15525 5.14 2.0 2.6
*Correcting factors for most species are from tables 42,
43, and 45, ratio of adult to juvenile vulnerability.
The correcting factor for the green-winged teal and the shoveler is assumed to be the same as that for the blue-winged
teal, and the correcting factor for the ring-necked duck the same as that for the lesser scaup.
production of mallards, and possibly all
species of waterfowl, seems to be inversely
related to population density.
Production in Different Species
Age ratios of ducks checked in hunters’
bags in the Mississippi Flyway for the
period 1946-1949 provide indices of pro-
duction for the various species, table 62.
At least a partial correction for the greater
vulnerability of juveniles than of adults
has been made by using banding data from
Illinois for the black duck and blue-winged
teal, tables 42 and 43, and banding data
from Canada for the mallard, gadwall,
baldpate, pintail, redhead, canvasback,
and lesser scaup, table 45. It has been
assumed that the ratio of adult to juve-
nile vulnerability in the green-winged teal
and shoveler is similar to that in the blue-
winged teal and that the ratio of adult
to juvenile vulnerability in the ring-
necked duck is similar to that in the lesser
scaup. Even though the calculations repre-
senting the “corrected number of juveniles
per adult hen,” table 62, were derived
from arbitrarily selected vulnerability
ratios, it is believed that they are so close
to the actual juveniles-per-hen figures that
some useful generalizations can be made.
The differences among the species are
not so great in the “corrected number of
juveniles per adult hen” asin the actual
number of juveniles per adult hen in
hunters’ bags, table 62. The vulnerability
differential between adults and juveniles
offers an explanation for the excessively
high ratios of 10 to 13 juveniles per adult
hen that have been found in checks of
hunters’ bags.
Several species of ducks appear to have
about equally high production rates, table
62: mallard, black duck, shoveler, ring-
necked duck, and canvasback. The bald-
pate and green-winged teal seem to be
intermediate in production. The gadwall,
pintail, blue-winged teal, redhead, and
lesser scaup appear to be species with
comparatively low production rates.
The fact of survival in a duck species
indicates that the species is adapted to
maintain its place in the total duck popu-
lation. The production of each species
must compensate for the losses suffered
through mortality, or the species declines.
With possibly a few exceptions, notably
the redhead and the wood duck, no duck
species has been known to undergo more
than a temporary major decline in popula-
ticn status in recent times.
Age Ratios in Population
Management
One aim of waterfowl management is
the establishment of hunting regulations
that will permit the greatest possible har-
4
&
5d G5 | alge i
*
—" ™ sj
Lae ios ahs eS Pe Bertie.
*]
:
‘
August, 1961
vest of birds without undue depletion of
populations. Age ratios obtained through
inspection of ducks in hunters’ bags offer
valuable assistance in determining the
well-being of populations and in evaluat-
ing the extent to which production may be
expected to replace annual losses.
An average annual production of 2.7
young of flying age per adult hen has been
estimated for mallards of the Mississippi
Flyway in the period 1939-1955, table 58.
Although this average figure and other
production figures shown in table 58 are
for the mallard only, they are of value in
making over-all hunting regulations be-
cause mallards comprise about half of the
duck population.
Major year-to-year changes in produc-
tion of the mallard, changes that probably
are present in other species also, require
flexibility in regulations governing the
duck kill.
Production data from age ratios need
to be supplemented by information from
the breeding grounds in the northern part
of the Mississippi Flyway. More informa-
tion is needed on the effect of different
combinations of regulations on mortality
in the mallard and other species of ducks.
Bellrose & Chase (1950:22) found evi-
dence that natural losses plus hunting
losses occurring under the regulations in
force in the years 1939-1947 resulted in
an annual mortality rate of about 48 per
cent in male mallards; the annual mor-
tality rate of the entire population was
somewhat higher.
The extent to which increased produc-
tion in ducks can compensate for in-
creased mortality is at present pure
speculation. The ability of animals to
compensate for annual variations in mor-
tality rates by flexibility in production is
widely recognized. More than 80 years
ago, Forbes (1880:9) wrote: “The fact
of survival is .. . usually sufficient evi-
dence of a fairly complete adjustment of
the rate of reproduction to the drains upon
the species.’ A few years ago, Allen
(1943 :113-4) cited the resilience of the
fox squirrel in compensating for severe
losses in number. Bump et al. (1947 :539-
40) reported for the ruffed grouse (Bon-
asa umbellus) in New York “a distinct
tendency for greater relative increases to
be associated with lower breeding popula-
BELLROSE et al.: SEX RATIOS AND AGE RarTIOos
467
tions.” Diem (1959: 304-5), in reporting
on duck production in an Alberta study
area, stated that some years “having low
breeding populations have witnessed
bumper crops of young.”
The probability that ducks have some
degree of elasticity in their capacity to
reproduce is shown by differences in pro-
duction among various species. It is shown
further by differences in production be-
tween the ducks of different flyways.
Although age ratios for Nebraska mallards
have tended to follow the same general
trend from year to year as those in Illinois,
they have consistently reflected lower num-
bers of juveniles per adult, fig. 16. There
is good evidence from banding and from
the percentage of birds carrying shot
wounds that shooting pressure is lighter
in the Central Flyway (and, therefore,
that the mallard undoubtedly has a lower
mortality rate in that flyway) than in
the Mississippi Flyway. Perhaps the ap-
parently lower reproduction rate of mal-
lards in the Central Flyway is the result
of the lower mortality rate there.
More data are needed on production
and mortality rates in various species of
ducks in each of the four flyways. By com-
paring production and mortality rates in
various species of ducks in each of the four
flyways, it would be possible to learn a
great deal more than is now known about
an apparent inverse relationship between
mortality and production and the opera-
tion of other population mechanisms of
waterfowl.
Waterfowl population research requires
a more concerted effort to appraise pro-
duction and to relate this to habitat condi-
tions. We recommend that state and
federal biologists, working through the
four flyway councils, make detailed and
uniform appraisals of conditions on the
breeding grounds and that, by use of age
ratios obtained from bagged ducks, they
determine yearly production for the im-
portant species.
The most feasible approach to the
problem of obtaining data on age ratios
appears to entail the establishment of sta-
tions where large samples of particular
species could be obtained. Some samples
should be taken where there is evidence
that a cross section of the migrating popu-
lation can be obtained or where the win-
468
tering populations exhibit a minimum of
regional bias. In some areas, a station
might be established at which the age
ratios for only one species of duck are
taken. For example, in the Mississippi
Flyway, the best station for sampling the
mallard might be Stuttgart, Arkansas; the
best for the gadwall, Mobile Delta, Ala-
bama; the best for the pintail and the
green-winged teal, the coastal marshes of
Louisiana; the best for the ring-necked
duck, Reelfoot Lake, Tennessee; the best
for the redhead and the canvasback, Lake
St. Clair and the Detroit River, Michigan.
SUMMARY
1. The present study is an evaluation
of sex and age ratios in North American
duck populations and the ways in which,
in waterfowl management, these ratios
can be used to measure productivity. (Page
391.)
2. Determination of sex composition
in duck populations presented a difficult
sampling problem complicated by differ-
ences in species, seasons, and places, and
by inadequate sampling techniques. (Page
393.)
3. In the study reported here, most
trapped or bagged ducks that could not be
readily sexed by plumage differences were
sexed by cloacal characters. (Page 396.)
4+. Four methods of sampling water-
fowl populations for sex ratios were used:
(1) examination of trapped ducks, (2) in-
spection of ducks taken by hunters, (3)
observation of ducks in the field, and
(4+) examination of disease victims. Biases
evident in each method were recognized,
and corrections were made whenever pos-
sible. (Page 396.)
5. Baited, funnel-type traps tended to
take disproportionate numbers of drakes,
while gate-type traps placed on shore
tended to catch a predominant number of
hens. (Pages 397, 400.)
6. Inspection of ducks in hunters’ bags
made possible the separation of drakes
and hens in molting adults and in juve-
niles. (Page 400.)
Most sex ratios derived from inspec-
tion of hunters’ bags showed little bias,
usually in favor of drakes. (Page 400.)
8. Banding records indicated that mal-
lard drakes were 1.05 times as likely to
Ittinois NaturRAL History Survey BULLETIN
Vol. 27, Art. 6
be shot by hunters as were hens, the dif-
ferential probably a result of hunter pref-
erence for drakes. (Page 401.)
9. A few field observations on living
ducks in spring were used to provide sex
data on samples of several species; how-
ever, because it is almost impossible to
make a sufficient number of random ob-
servations to insure an adequate sampling
of the population of a flyway or other
large area, field observations were not
more extensively used. (Pages 401-2.)
10. The validity of sex ratios obtained
from examination of ducks that were vic-
tims of disease was found to need further
study. (Page 402.)
11. Analysis of available data showed
no significant departure from an evenly
balanced sex ratio in ducks at fertilization
or at hatching. (Pages 402-3.)
12. Data obtained from examining
juvenile ducks trapped during the breed-
ing season or taken by hunters during the
fall indicated that the ratio between the
sexes from the time of hatching to adult-
hood was close to 50:50; local variations
appeared to result from differences in sea-
sonal movements. (Pages 403-5.)
13. Although sex ratios of adults usu-
ally favored drakes, there were numerous
exceptions. (Pages 405-6.)
14. Sex ratios of many species of ducks
varied from week to week in any given
area as the composition of the local popula-
tion changed with the arrival and de-
parture of flocks containing varying num-
bers of drakes and hens. (Page 408.)
15. In most species of ducks for which
data were available, drakes made up a
smaller proportion of the hunters’ kill in
Manitoba than in three states to the south
(North Dakota, Illinois, and Tennessee),
indicating that more drakes than hens left
Manitoba in advance of the hunting sea-
son. Among adult mallards bagged in
Illinois, there was a steady increase in the
drake segment through the third week in
November, followed by a period of stabi-
lized sex ratios, and then further increase
in the drake segment of the wintering
population, usually present in Illinois after
the first week in December. In Utah, sex
ratios of adult mallards bagged by hunters
were relatively stable throughout fall. In
only a few species did there appear to be
differences in seasonal movements between
August, 1961
drakes and hens in the juvenile class.
(Pages 408-9.)
16. Periodic counts of ducks in late
winter and early spring revealed differ-
ences in the sequence of northward migra-
tion of drakes and hens of the same species.
(Pages 411-16.)
17. The first spring flights arriving in
Manitoba showed, with minor exceptions,
a closer approach to a balance between
sexes than did subsequent populations.
(Pages +16—9.)
18. Sex ratios in ducks were found to
vary with migration routes and various
areas of their wintering grounds. (Pages
419-20.)
19. Information collected on the prin-
cipal mortality factors affecting the North
American duck population indicates that
hunters and disease take relatively more
drakes than hens. This information is not
sufficient to permit appraisal of the in-
fluence of predation on sex ratios; how-
ever, appreciable losses among hens during
the breeding season, most of these losses
apparently attributable to predation, agri-
cultural operations, and stress, may ac-
count for the predominance of drakes in
the adult class. (Page 426.)
20. Data showed that, the more pro-
ductive a species of waterfowl, the greater
is apt to be the proportion of juveniles in
its population at the opening of the hunt-
ing season; the greater the proportion of
juveniles in a population, the more nearly
balanced is its sex ratio. (Page 426.)
21. Drakes occurred in relatively
greater numbers among diving ducks than
among dabblers; however, examination of
the available knowledge on the reproduc-
tive biology characterizing these two sub-
families revealed nothing which suggests
that extra drakes may be more important
to the maintenance of populations of div-
ing ducks than of dabblers. (Page 427.)
22. The study suggested that the value
of extra drakes needs investigation through
an experimental procedure designed to re-
duce the number of drakes in a subpopula-
tion of a species having a large drake
segment. (Page 428.)
23. Sex ratios that were derived from
inspection of mallards in hunters’ bags in
Illinois provide a fair index to production
but not so good an index as age ratios;
sex ratios obtained from observations on
BELLROSE et al.: SEx RATIOS AND AGE Ratios
469
the breeding grounds in Canada do not
appear to provide a more reliable index to
production than sex ratios calculated from
bag inspections in Illinois. (Page 429.)
24. Age ratios alone, this study as-
sumed, are seldom true indices of water-
fowl production, but they offer a promis-
ing basis for measuring it. (Page 430.)
25. In this study, age ratios were ob-
tained by examination of ducks trapped
for banding, shot by hunters, or killed by
disease. (Page 431.)
26. Although most traps were selec-
tive for adults, ducks taken in traps were
found to provide a rough index to yearly
changes in age ratios. (Pages 431-5.)
27. Juveniles were found to be more
vulnerable to hunting than adults; the
vulnerability differential varied with place,
time of hunting season, year, and species.
(Pages 435-9.)
28. Age ratios obtained from bagged
ducks and corrected for the greater vulner-
ability of juveniles offered the best means
of determining the adult-juvenile compo-
sition of duck populations. (Page 439.)
29. Age ratios derived from waterfowl
lost to severe outbreaks of disease were
considered unreliable because of the ir-
regular occurrence and site limitations of
such outbreaks. (Pages 439-40.)
30. Because juveniles and adults do
not follow identical migration schedules
or routes, age ratios showed seasonal and
regional variations. (Pages 440-9.)
31. Age ratios were found to be use-
ful for appraising the production of ducks
if the data on which they are based have
been carefully evaluated as to the effect of
seasonal, regional, and shooting biases.
(Page 449.)
32. A production curve (page 449)
that was plotted from corrected age data
for mallards in hunters’ bags in the Mis-
sissipp! Flyway for 17 years, 1939-1955,
follows a pattern somewhat similar to that
plotted from uncorrected data and shows
a somewhat rhythmic production trend
that may be inherently characteristic of
waterfowl populations and prove to be
density dependent in origin. (Page 454.)
33. A comparison of mallard age ratios
in the Mississippi Flyway with pintail age
ratios in the Pacific Flyway for 11 years,
1949-1959, revealed for most years an un-
expectedly close agreement between pro-
470
duction trends of the two species involved.
(Pages 454-5.)
34. For the period 1952-1959, the
population curve plotted from forecast in-
dices of waterfowl production in Sas-
katchewan was similar to the curve plotted
from the Mississippi Flyway age ratios
for mallards. Manitoba forecast indices
showed very little correlation with mal-
lard age ratios from the Mississippi Fly-
way, possibly because, as aerial surveys in-
dicated, about six times as many mallards
nest in the plains and parklands of Sas-
katchewan as in the plains and parklands
of Manitoba, and because the Saskatche-
wan contribution to the Mississippi Fly-
way kill of mallards is larger than that of
Manitoba. (Page 457.)
35. An attempt was made to correlate
water conditions on the breeding grounds
with mallard production. In Sasketche-
wan, mallard production (as determined
by the number of juveniles per adult
among birds bagged in Illinois) and wa-
ter abundance (as measured by the num-
ber of ponds per square mile in May) fol-
lowed similar trends in most years of the
period 1948-1959. In Manitoba, mallard
production tended to parallel water abun-
dance in the years 1956-1959 but not in
the 3 years previous. (Page 462.)
36. Decreased production by the mal-
lard on the plains of Canada in years of
very plentiful water and of cold weather,
snow, and heavy rains at nesting time sug-
gests that cold, excessively wet springs
may be as unfavorable to duck production
as dry, warm springs. (Page 463.)
[Ltrnors NaturAL History SurvEY BULLETIN
Vol. 27, Art. 6
37. Population density, as well as wa-
ter and weather conditions on the breeding
grounds, seems to have contributed to
gross changes in mallard production in
1939-1959; it may well have been the
dominant factor regulating production
during those years in which there was
poor correlation between age ratios and
conditions on the breeding grounds. (Page
463.)
38. Age ratios of ducks checked in
hunters’ bags in the Mississippi Flyway
for the period 1946-1949 provided indices
of production for the various species. Sev-
eral species appear to have had about
equally high production rates: mallard,
black duck, shoveler, ring-necked duck,
and canvasback. The baldpate and green-
winged teal seem to have been intermedi-
ate in production. The gadwall, pintail,
blue-winged teal, redhead, and _ lesser
scaup appear to have had production rates
lower than those of the other species.
(Page +66.)
39. Age ratios obtained through inspec-
tion of ducks in hunters’ bags were found
to be of value in establishing hunting reg-
ulations, for they provide a basis for evalu-
ating the well-being of the population and
the extent to which production may be ex-
pected to replace annual losses. (Pages
466-7.)
40. Further progress in waterfowl pop-
ulation management, the study concluded,
requires a more concerted effort to obtain
age ratio data by design and to relate these
data to conditions on the breeding grounds.
(Page 467.)
EEE RAT OO RE ChECE D
Anonymous
1957. Check-list of North American birds. Fifth edition. American Ornithologists’ Union,
Baltimore, Maryland. 691 pp.
Allen, Durward L.
1943. Michigan fox squirrel management. Mich. Dept. Cons. Game Div. Pub. 100. 404 pp.
Anderson, Maurice E.
1953. A study of the efficiency of methods of estimating duck brood production, 1952. South
Dakota Department of Game, Fish and Parks, Pierre. 22 pp.
Baskett, Thomas S.
1947. Nesting and production of the ring-necked pheasant in north-central Iowa. Ecol.
Monog. 17(1) :1-30.
Beer, James R.
1945. Sex ratios of ducks in southwestern Washington. Auk 62(1) :117-24.
Bellrose, Frank C.
1944. Duck populations and kill: an evaluation of some waterfowl regulations in Illinois.
Ill. Nat. Hist. Surv. Bul. 23(2) :327-72.
1955. A comparison of recoveries from reward and standard bands. Jour. Wildlife Met.
19(1):71-5.
1959. Lead poisoning as a mortality factor in waterfowl populations. Ill. Nat. Hist. Surv.
Bul. 27(3):235-88.
Bellrose, Frank C., and Elizabeth Brown Chase
1950. Population losses in the mallard, black duck, and blue-winged teal. Ill. Nat. Hist.
Surv. Biol. Notes 22. 27 pp.
Bump, Gardiner, Robert W. Darrow, Frank C. Edminster, and Walter F. Crissey
1947. The ruffed grouse: life history, propagation, management. New York State Con-
servation Department, [Albany]. 915 pp.
Carney, Samuel M., and Aelred D. Geis
1960. Mallard age and sex determination from wings. Jour. Wildlife Mgt. 24(4) :372-81.
Cartwright, Bertram W.
1956. Waterfowl banding, 1939-1954, by Ducks Unlimited. Ducks Unlimited, Winnipeg,
Manitoba, Canada. 35 pp. Second edition (revised).
Cartwright, Bertram W., and Jean T. Law
1952. Waterfowl banding, 1939-1950, by Ducks Unlimited. Ducks Unlimited, Winnipeg,
Manitoba, Canada. 53 pp.
Colls, D. G.
[1950.] Waterfowl breeding ground survey in Saskatchewan, 1950. U.S. Fish and Wildlife
Serv. and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 8:36—40.
Colls, D. G., and J. J. Lynch
[1951.] Waterfowl breeding ground survey in Saskatchewan, 1951. U.S. Fish and Wildlife
Serv. and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 13:35—-40.
Crissey, W. F.
1954. 1954 status report of waterfowl. U. S. Fish and Wildlife Serv. Spec. Sci. Rep.—
Wildlife 26. 97 pp.
Diem, Kenneth L.
1959. Some aspects of wildlife population dynamics, their interpretation and role in game
management. N. Am. Wildlife Conf. Trans. 24:304-11.
Dzubin, Alex
1959. Growth and plumage development of wild-trapped juvenile canvasback (Aythya
valisineria). Jour. Wildlife Mgt. 23(3) :279—-90.
Erickson, Arnold B.
1943. Sex ratios of ducks in Minnesota, 1938-1940. Auk 60(1) :20—34.
Errington, Paul L.
1943. An analysis of mink predation upon muskrats in north-central United States. Iowa
Ag. Expt. Sta. Res. Bul. 320:797-924.
1945. Some contributions of a fifteen-year local study of the northern bobwhite to a knowl-
edge of population phenomena. Ecol. Monog. 15(1) :1-34.
Evans, Charles D.
1955. Waterfowl populations and breeding conditions in southern Manitoba, 1954. U. S.
Fish and Wildlife Serv. and Can. Wildlife Serv. Spec. Sci. Rep.—Wildlife 27:71-81.
Evans, Charles D., and Kenneth E. Black
1956. Duck production studies on the prairie potholes of South Dakota. U. S. Fish and
Wildlife Serv. Spec. Sci. Rep.—Wildlife 32:1-59.
Evenden, Fred G., Jr.
1952: eens sex ratios observed in the western United States. Jour. Wildlife Met.
16 (3) :391-3.
[ 471 ]
472 ILttinois NaTuRAL History Survey BULLETIN Vol. 27, Art. 6
Forbes, 5S. A. :
1880. On some interactions of organisms. II]. Lab. Nat. Hist. Bul. 1(3):3-17.
Fuller, Robert W., and Jessop B. Low :
1951. Studies in the life history and ecology of the American pintail. Utah Coop. Wildlife
Res. Unit Quart. Activ. Rep. 16(3) :40-3.
Furniss, O. C.
1935. The sex ratio in ducks. Wilson Bul. 47(4):277-8.
1938. The 1937 waterfowl season in the Prince Albert district, central Saskatchewan.
Wilson Bul. 50(1):17-27.
Geis, Aelred D. ee
1959. Annual and shooting mortality estimates for the canvasback. Jour. Wildlife Mgt.
23 (3) :253-61.
Glover, Fred A.
1951. Spring waterfowl migration through Clay and Palo Alto counties, lowa. Lowa State
Col. Jour. Sci. 25(3) :483-92.
Gollop, J. B. ;
1954. Waterfowl breeding ground survey in Saskatchewan—1953: special study area—
Kindersley-Eston. U. S. Fish and Wildlife Serv. and Can. Wildlife Serv. Spec. Sci.
Rep.—Wildlife 25:65-73.
Gollop, J. B., and J. J. Lynch
1955. Waterfowl breeding ground survey, Saskatchewan—1954. U. S. Fish and Wildlife
Serv. and Can. Wildlife Serv. Spec. Sci. Rep.— Wildlife 27:45-55.
Gollop, J. B., John J. Lynch, and William Hyska yen
[1952.] Waterfowl breeding ground survey in Saskatchewan. U. S. Fish and Wildlife Serv.
and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 21:33—40.
Gower, W. Carl :
1939. The use of the bursa of Fabricius as an indication of age in game birds. N. Am.
Wildlife Conf. Trans. 4:426-30.
Hammond, M. C.
1949. Sample variation in local waterfowl sex ratios. Miss. Flyway Waterfowl Com. News
Letter 9:7-9.
1950. Some observations on sex ratio of ducks contracting botulism in North Dakota. Jour.
Wildlife Mgt. 14(2) :209-14.
Hanson, Harold C.
1949. Methods of determining age in Canada geese and other waterfowl. Jour. Wildlife
Mgt. 13(2) :177-83.
Hawkins, Arthur S.
1948. Waterfowl breeding conditions in Manitoba, 1947. U. S. Fish and Wildlife Serv.
Spec. Sci. Rep. 45:39-57.
1949. Waterfowl breeding ground survey in Manitoba—1949. U.S. Fish and Wildlife Serv.
and Dominion Wildlife Serv. Spec. Sci. Rep.: Wildlife 2:53-65.
[1950.] Waterfowl breeding ground survey in Manitoba, 1950. U.S. Fish and Wildlife Serv.
and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 8:41-8.
1954. Waterfowl breeding ground survey in Manitoba. U. S. Fish and Wildlife Serv. and
Can. Wildlife Serv. Spec. Sci. Rep.— Wildlife 25:74-80.
Hawkins, Arthur S., Frank C. Bellrose, Jr., and Robert H. Smith
1946. A waterfowl reconnaissance in the Grand Prairie region of Arkansas. N. Am.
Wildlife Conf. Trans. 11:394-401.
Hawkins, Arthur S., and F. Graham Cooch
1948. Waterfowl breeding conditions in Manitoba, 1948. U. S. Fish and Wildlife Serv.
and Dominion Wildlife Serv. Spec. Sci. Rep. 60:76-98.
Hawkins, A. S., J. B. Gollop, and E. G. Wellein
[1951.] Waterfowl breeding ground survey in Manitoba, 1951. U.S. Fish and Wildlife Serv.
and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 13:41-9.
Hawkins, Arthur S., and Edward G. Wellein
[1952.] Waterfowl breeding ground survey in Manitoba. U. S. Fish and Wildlife Serv. and
Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 21:61-5.
Hickey, Joseph J.
1952. Survival studies of banded birds. U. S. Fish and Wildlife Serv. Spec. Sci. Rep.:
Wildlife 15. 177 pp.
Hjelle, Brandt V.
1950. Bag check—1949 season. N. Dak. Outdoors 12(8):14.
Hochbaum, H. Albert
1942. Sex and age determination of waterfowl by cloacal examination. N. Am. Wildlife
Conf. Trans. 7:299-307.
1944. The canvasback on a prairie marsh. American Wildlife Institute, Washington, D. C.
201 pp.
1946. pAb potentials in North American waterfowl. N. Am. Wildlife Conf. Trans.
7403-16.
August, 1961 BELLROSE et al.: SEX RATIOS AND AGE Ratios 473
Hopkins, Ralph C.
1947. Waterfowl management research. Wis. Wildlife Res. Prog. Reps. 5(4):12-33.
Johnsgard, Paul A., and Irven O. Buss
1956. Waterfowl sex ratios during spring in Washington state and their interpretation.
Jour. Wildlife Mgt. 20(4) :384-8.
Jordan, James S.
1953. Consumption of cereal grains by migratory waterfowl. Jour. Wildlife Mgt. 17(2):
120-3.
Jordan, James S., and Frank C. Bellrose
1951. Lead poisoning in wild waterfowl. Ill. Nat. Hist. Surv. Biol. Notes 26. 27 pp.
Kabat, Cyril, R. K. Meyer, Kenneth G. Flakas, and Ruth L. Hine
1956. Seasonal variation in stress resistance and survival in the hen pheasant. Wis. Cons.
Dept. Tech. Wildlife Bul. 13. 48 pp.
Kalmbach, E. R.
1937. Crow-waterfowl relationships in the Prairie Provinces. N. Am. Wildlife Conf. Trans.
2:380-92.
Labisky, Ronald F.
1957. Relation of hay harvesting to duck nesting under a refuge-permittee system. Jour.
Wildlife Mgt. 21(2) :194-200.
Lebret, T.
1950. ‘The sex-ratios and the proportion of adult drakes of teal, pintail, shoveler and
wigeon in the Netherlands, based on field counts made during autumn, winter and
spring. Ardea 38(1-2) :1-18.
Leopold, Aldo
1933. Game management. Charles Scribner’s Sons, New York. 481 pp.
Lincoln, Frederick C.
1932. Do drakes outnumber susies? Am. Game 21(1) :3-4, 16-7.
Low, Jessop B.
1941. Spring flight of the diving ducks through northwestern Iowa. Condor 43(3) :142-51.
Lynch, John J.
1948. Waterfowl breeding conditions in Saskatchewan, 1947. U.S. Fish and Wildlife Serv.
Spec. Sci. Rep. 45:21-38.
1949. Waterfowl breeding ground survey in Saskatchewan, 1949. U.S. Fish and Wildlife
Serv. and Dominion Wildlife Serv. Spec. Sci. Rep.: Wildlife 2:48-52.
Lynch, J. J., and J. B. Gollop
1954. Waterfowl breeding ground survey in Saskatchewan. U. S. Fish and Wildlife Serv.
and Can. Wildlife Serv. Spec. Sci. Rep.—Wildlife 25:43—54.
Mann, Roberts, David H. Thompson, and John Jedlicka
1947. Report on waterfowl banding at McGinnis Slough Orland Wildlife Refuge for the
years 1944 and 1945. Forest Preserve District of Cook County, Illinois. 235 pp.
Mainland, Donald, Lee Herrera, and Marion I. Sutcliffe
1956. Statistical tables for use with binomial samples—contingency tests, confidence limits,
sample size estimates. New York University College of Medicine, New York, N. Y.
83 pp.
Mayr, Ernst
1939. The sex ratio in wild birds. Am. Nat. 73(745):156-79.
Mcllhenny, E. A.
1940. Sex ratio in wild birds. Auk 57(1):85-93.
Milonski, Mike
1958. The significance of farmland for waterfowl nesting and techniques for reducing
losses due to agricultural practices. N. Am. Wildlife Conf. Trans. 23:215-26.
Mumford, Russell E.
1954. Waterfowl management in Indiana. Ind. Dept. Cons. P.-R. Bul. 2. 99 pp.
Munro, J. A.
1943. Studies of waterfowl in British Columbia: mallard. Can. Jour. Res. 21(D):223-60.
Nelson, Harvey K.
1950. A study of waterfowl sex ratios during spring migration—Minnesota, 1950. Flicker
22(4) :114+20.
Owen, Richard
1866. On the anatomy of vertebrates. Vol. 2, Birds and mammals. Longmans, Green, and
Co., London. 592 pp.
Petrides, George A.
1944. Sex ratios in ducks. Auk 61 (4) :564-71.
Petrides, George A., and Charles R. Bryant
1951. An analysis of the 1949-50 fowl cholera epizootic in Texas Panhandle waterfowl.
N. Am. Wildlife Conf. Trans. 16:193-216.
Pirnie, Miles David
1935. Michigan waterfowl management. Michigan Department of Conservation, Lansing.
328 pp.
474 Inuinois NaTurAL History Survey BULLETIN Vol. 27, Art. 6
Rosen, Merton N., and Arthur I. Bischoff
1950. The epidemiology of fowl cholera as it occurs in the wild. N. Am. Wildlife Conf.
Trans. 15:147-53.
Schroeder, Charles H.
1959. No water! No ducks! N. Dak. Outdoors 22(4) :4—5.
Selye, Hans
1956. The stress of life. McGraw-Hill Book Company, Inc., New York. 325 pp.
Singleton, J. R. ;
1953. Texas coastal waterfowl survey. Tex. Game and Fish Comn, FA Rep. Ser. 11. 128 pp.
Smith, Allen G.
[1959.] Progress report: the 1959 waterfowl surveys of the Lousana study area, Lousana,
Alberta, Canada. United States Bureau of Sport Fisheries and Wildlife, Wildlife
Research Laboratory, Denver, Colorado. 15 pp.
Smith, Robert H.
1948. Aerial reconnaissance of the Prairie Provinces. U. S. Fish and Wildlife Serv. Spec.
Sci. Rep. 45:58-68.
Soper, J. Dewey
1948. Waterfowl breeding conditions in Saskatchewan, 1948. U.S. Fish and Wildlife Sery.
and Dominion Wildlife Serv. Spec. Sci. Rep. 60:56-75.
Sowls, Lyle K. ;
[1950.] Notes on the chronology of the 1950 waterfowl nesting season in southern Manitoba.
U. S. Fish and Wildlife Serv. and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife
8:59-61.
1955. Prairie ducks, a study of their behavior, ecology and management. Stackpole Com-
pany, Harrisburg, Pennsylvania, and Wildlife Management Institute, Washington,
DaCh7193" pp.
Stokes, Allen W.
[1954.] Population studies of the ring-necked pheasants on Pelee Island, Ontario. Ont. Dept.
Lands and Forests Tech. Bul.: Wildlife Ser. 4. 154 pp.
Stoudt, Jerome H.
[1952.] Waterfowl breeding ground survey of Redvers area, Saskatchewan. U. S. Fish and
Wildlife Serv. and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 21:52-60.
[1959.] 1959 progress report: Redvers Waterfowl Study Area with comparative data for
seven previous years. United States Bureau of Sport Fisheries and Wildlife, Wild-
life Research Laboratory, Denver, Colorado. 110 pp.
Stoudt, Jerome H., and Raymond J. Buller
1954. Waterfowl breeding ground survey of Redvers area, Saskatchewan. U. S. Fish and —
Wildlife Serv. and Can. Wildlife Serv. Spec. Sci. Rep.: Wildlife 25:55—-64.
Stoudt, Jerome H., and Marshall Stinnett
1955. Waterfowl breeding ground survey of Redvers area, Saskatchewan, 1952-1954.
U. S. Fish and Wildlife Serv. and Can. Wildlife Serv. Spec. Sci. Rep—Wildlife
27:56-65.
Teplov, V. F., and N. N. Kartashev
1958. Wildfowl research in Russia; biological foundations for the regulation of wild-
fowling in the central districts of the European part of the U.S.S.R. Pp. 157-69 in
Ninth Annual Report of the Wildfowl Trust, 1956-1957. Country Life, Ltd., London.
239 pp.
Ticehurst, Claud B.
1938. On a character of immaturity in the Anatidae. Ibis, fourteenth series, 2(4):772-3.
Van Den Akker, John B., and Vanez T. Wilson
1951. Public hunting on the Bear River Migratory Bird Refuge, Utah. Jour. Wildlife
Met. 15(4) :367-81.
Weller, Milton W.
1957. erie weights, and plumages of the redhead, Aythya americana. Wilson Bul.
69 (1) :5-38.
Williams, C. S.
1953. 1953 status report of waterfowl. U. S. Fish and Wildlife Serv. Spec. Sci. Rep.—
Wildlife 22. 64 pp.
Yocom, Charles F.
1949. A study of sex ratios of mallards in the state of Washington. Condor 51(5):222-7.
Co
INDEX
The following index covers Articles 1, 2, 3, 4, 5, and 6 of Volume 27 of the ILLINOIS
NaTuRAL History SURVEY BULLETIN. Indexing has been limited for the most part to the names
of birds, fish, insects, mammals, and plants mentioned in the articles.
In most cases, the
singular form of the word has been used in the index, even though the plural form has been
used in the text, as mouse for both mice and mouse. Place names have not been indexed.
Of necessity, variation occurs in some of the terms. For example, peach in the index may
refer to either the fruit or the tree.
A
Abelia, 151
Abutilon theophrasti, 326
Acanthocephala (acanthocephalan), 66, 137
Acarina, 297, 300, 303, 305, 307, 309, 312, 319,
322, 339
Acnida altissima, 294, 298, 302, 304, 314, 323-4,
332-3; see also Water-hemp
Aeshna, 296, 305
Aix sponsa, 254, 312, 394; see also Duck, wood
Alderfly, 140
Alfalfa, 150-1, 185, 425
Algae, 16, 18, 20-2. 161. 170, 306, 308-10, 325,
355, 357-8, 380, 387
plankton, 355-7
Alisma subcordatum, 325
Alona, 12
Amaranth, green, 326
Amaranthus retroflexus, 326
Amaryliis, 158
Ambloplites rupestris, 1; see also Bass, rock
Ambrosia
artemistifolia, 321, 325
psilostachya, 325
trifida, 325
Ammannia coccinea, 327
Amnicola, 296, 299, 320, 338, 340
binneyana, 319
peracuta, 316
Amphibia (amphibian), 134, 136, 297, 339-40,
372
Amphipoda (amphipod), 12, 15-6, 18, 24, 27,
52, 296, 299, 305, 340
Anacharis canadensis, 326
Anas
acuta, 233, 297, 393; see also Duck, pintail
(American)
carolinensis, 247, 303, 394; see also Duck,
green-winged teal
cyanoptera, 247; see also Duck, cinnamon
teal
diazi, 394
discors, 247, 393; see also Duck, blue-winged
teal
fulvigula, 394
platyrhynchos, 238, 293, 393; see also Duck
’
mallard
rubripes, 257, 293, 314, 394; see also Duck,
black
Sstrepera, 247, 308, 394; see also Duck, gad-
wall
Anax junius, 299, 316
Ancylidae, 12
Anguilla rostrata, 5
Animal, 119, 125, 127-8, 132, 134, 144, 161, 180,
197-8
aquatic, 163, 178
domestic, 346
moss, 338
wild, 201
Animal foods [of waterfowl], 292-3, 295-7,
299-303, 305-23, 337-40, 343
Anisoptera, 12, 14-6, 18, 20-2, 29, 296, 299, 305,
338
Annelida (annelid), 12, 15, 22
Annuals, 145
Anser albifrons, 247; see also Goose, white-
fronted
Anseriformes, 191
Ant, 29, 297, 300, 305, 316, 339
Anthomylidae, 316, 339
Aphid, 100, 112, 118, 121, 132-5, 138-40
corn root, 117
pea, 118, 123
spotted alfalfa, 118, 123
Aphis, 121
A phodius
distinctus, 297, 299, 309, 312, 319; see also
Beetle, scarab
femoralis, 312, 316
Apidae, 13
Apis mellifera, 13
Apple, 105-10, 130, 151-2
crab, 157
Apple-leaf folder, lesser, 105
Apricot, 107, 151
Arachnida (arachnoid), 137, 297, 300, 303, 305,
307, 309, 316, 319, 322, 339
Araneae, 12, 16, 18, 22, 300, 316, 319
Arbor vitae
American, 146
Chinese, 146
Siberian, 146
Ardes herodias, 65
Argia apicalis, 12
Argiopoidea, 300, 322
Armyworm, 114-5, 117, 123
fall, 123-4
Arrenurus, 12
Arrowhead, common, 300, 337
Arthropoda, 296, 299, 303, 305, 307, 309, 312-4,
316, 319-20, 322, 338
Asellus, 12, 15, 296, 299, 305
communis, 15
Ash, 158, 160
mountain, 157
wafer, 151
Aster, 158
Ataenius, 13
Avena sativa, 327; see also Oats
Avens, 327
Aythya, 430
affinis, 239, 315, 393; see also Duck, lesser
scaup
americana, 254, 321, 394; see also Duck, red-
head
[ 475 |
476
A ythya—continued '
collaris, 254, 317, 393; see also Duck, ring-
necked
marila, 23%, 323; see also Duck, greater
scaup
valisineria, 238, 320, 394; see also Duck,
canvasback
Azalea, 158
B
Backswimmer, 296, 338 =~
Bacteria, 27, 77, 147, 153, 161
Bagworm, 118
Barley, 117, 151
Bass, 165, 171-2, 176, 353-6, 362-5, 367, 371-2,
375-7, 379-88
black, 164
largemouth, 5-6, 10-3, 22-3, 28-9, 36, 49, 62,
68-77, 79, 164, 170, 172-8, 345, 353-4, 359-
61, 365-6, 368, 370-1, 374, 376, 378-382,
384, 387
rock, 1, 43
smallmouth, 5, 72, 74-6, 79, 175-6, 178
spotted, 5
yellow, 5
Bean, 152
navy, 326
trailing wild, 326
wild, 326
Beaver, 196
Bedbug, 104, 123
Bee, 29, 121, 135
bumble, 100
Beet, 111
Beetle, 29, 129, 142
asparagus, 105
bark, 118
bean leaf, 118
carpet, 123
Colorado potato, 104-5, 109, 111-2, 115,
123-4
corn flea, 151
cucumber, 111
diving, 296, 299, 303, 305, 307, 309, 312, 314,
316, 319-20, 322, 339
ground, 296, 299, 303, 305, 312, 316, 319-20,
339
Japanese, 104
June, 135, 143
leaf, 135, 297, 300, 305, 307, 313, 319, 339
Mexican bean, 104
rove, 135) 296, 299, 305, 312,-339
scarab, 297, 299, 307, 309, 312, 319, 339
snout, 106, 297, 300, 303, 316, 320, 339
water, 135, 322
water scavenger, 296, 299, 314, 316, 339
whirligig, 296, 303, 305, 312, 319, 339
Beggar-tick, 325
Begonia, 158
Belostoma, 13
Belostomatidae (on some pages misspelled
Belastomatidae), 13, 296, 299, 319, 338
Benacus, 319
Berosus, 13
Bidens frondosa, 325
Billbug, 117
Birch, 118
Bird, 86, 96, 105, 120-1, 129-30, 136, 179-81,
183-4, 188, 206, 210
Intinors NarurAL History Survey BULLETIN
Volume 27
fish-eating, 164
game, 181, 183, 199
migratory game, 182
nongame, 182-3
song-, 198
upland game, 182, 186
water, 205
Blackberry, 152
Blackbird, red-winged, 121
Blastobasidae, 144
Blight, 112
Blissus leucopterus, 116-7; see also Bug, chinch
Blue jay, 186
Bluegill, 4-6, 8-10, 39-40, 62, 67-9, 71-2, 74-6,
172-3, 176-8, 345, 353-6, 362-8, 370-88;
see also Lepomis macrochirus
Bobwhite, see Quail
Bonasa umbellus, 467
Bootjack, 337
Borer
clover root, 118
elm, 154
European corn, 104, 112, 122-3, 143
flat-headed, 118
flatheaded wood, 296, 339
peach tree, 108
round-headed, 118
squash vine, 111
stalk, 117
tree, 108
Branchiopoda, 305, 338, 340
Branta canadensis, 239, 425; see also Goose,
Canada
Bream, 71
Bruchus granarius, 105
Bryophyte, 161
Bryozoa (bryozoan), 12, 16, 20, 22, 296, 299,
303, 305-8, 312, 316, 319, 322, 338, 340
Bucephala
albeola, 259; see also Duck, buftehead
clangula, 247, 323; see also Duck, common
goldeneye
Buckeye, 158
Buckwheat
climbing false, 294, 324
common, 325
Buftalo, 128
Buffalo [fish], 164, 172-3
mongrel, 172
redmouth, 172
Bug, 29, 86, 89, 91, 114
chinch, 93, 114-7, 121, 123-4, 296, 299, 338
plant, 140, 338
squash, 316, 339
stink, 139, 296, 339
water, 296, 299, 319, 338
Bullhead
black, 5, 172, 176
yellow, 5
Bulrush
alkali, 322, 325
American, 292, 325
green, 325
hard-stem, 309, 318, 325
river, 196, 309, 318, 321, 323, 325, 334, 337,
343
soft-stem, 292, 309, 318, 321, 325
Buprestidae, 13, 296, 339
Bur-reed, 193
J
Y.
ay
<n
ae
1957-1961
giant, 292, 318, 323, 325, 337, 343
Buttercup, 325
Butterfly, imported cabbage, 104
Buttonbush, 292, 294, 298, 300, 302, 304, 306,
311, 313-4, 318, 323-4, 334, 343
Buttonweed, 327
C
Cabbage, 111, 113
Caddistly, 15, 21, 23-6, 28, 52, 135, 140, 142,
297, 300, 303, 305, 307, 309, 312, 314, 316,
339-40
Caenis, 12, 14-5, 27, 29, 299, 305, 338
Calla, 158-9
Callimorpha Lecontei, 105
Camallanus oxycephalus, 65-6, 78
Cambarus virilis, 296, 316
Campeloma, 296, 299, 316, 319, 338, 340
Candona, 305
Cankerworm, 109, 118, 183
spring, 155
Canthocam pus, 305
Carabidae, 296, 299, 303, 305, 307, 312, 316,
319-20, 339
Carex rostrata, 326
Carinifex, 338
newherryl, 296
Carnation, 158
Carp, 4-5, 164, 172-3, 386
Carpiodes cyprinus, 5
Carpsucker, quillback, 5
Carrot, 111
Casnonia pennsylvanica, 299
Cassia fasciculata, 326
Catalpa, 157, 160
Caterpillar
pear, 105
tent, 118
walnut, 118
Catfish, 6, 172
channel, 5, 176, 386
flathead, 5
Catostomus commersoni, 5
Cattail, 196
Cattle, 178, 346
Cedar
deodar, 146
of Lebanon, 146
red, 146
Celithemis, 12
Celtis occidentalis, 326; see also Hackberry
Centrarchidae (centrarchid), 1, 65, 70, 78, 171,
178
Cephalanthus occidentalis, 294, 298, 302, 304,
306, 311, 313-4, 318, 323-4, 334; see also
Buttonbush
Ceratophyllum demersum, 294, 298, 302, 304,
306, 309, 311, 313-5, 318, 320-1, 323-4, 330;
see also Coontail
Ceratopogonidae, 13
Cestoda (cestode), 12, 15, 21-2
Chaenobryttus gulosus, 1, 5, 13, 76, 174; see
also Warmouth
Chaetocnema, 319
pulicaria, 151
Chafers, vine leaf, 183
Chaoborus, 13, 26
Chara, 355, 358, 376, 387
Charadriiformes, 191
INDEX 477
Chen
caerulescens, 244; see also Goose, blue
hyperborea, 244; see also Goose, snow
Chenopodium album, 325
Cherry, 107, 151-2, 327
Chicken, prairie, 103, 183, 186-7, 198
Chironomidae (chironomid), 13, 139, 297, 300,
303, 305, 307, 309, 312, 316, 319-20, 322,
339
Chordata, 297, 300, 319-20, 339
Chrysanthemum, 158
Chrysomelidae, 13, 143, 297, 300, 305, 307, 313,
319, 339
Chubsucker, lake, 5
Chufa, 247, 292, 294-5, 298, 302, 304, 311, 318,
323-4, 335, 343
Chydorus, 12
Cicadellidae, 141, 296, 307, 338
Cicadellinae, 142
Ciliate, 27
Cinquefoil, 326
Cladium mariscoides, 326
Cladocera (cladoceran), 12,
24-5, 27-8, 51
Clam, fresh-water, 296, 299, 338
Clangula hyemalis, 323; see also Duck,
oldsquaw
Clover, 108, 114, 185, 327
sweet, 151
Cloverworm, green, 118
Coccidia, 191
Cockroach, 123
Coenagrionidae, 296, 299, 305
Coleoptera, 13, 16, 18, 20-2, 29, 129, 142, 296,
299, 303, 305, 307, 309, 312-4, 316, 319-20,
822, 339
Coleus, 159
Colinus virginianus, 341; see also Quail
Collembola (collembolan), 12, 15, 20, 22, 144
Colymbetes, 299
Compositae, 326
Coniothyrium, 155
Convolvulus arvensis, 327
Coontail, 193, 269, 294-5, 298, 300-2, 304, 306,
308-11, 313-5, 317-8, 320-4, 327, 330, 343
Coot, 261
Copepoda (copepod), 12, 15-6, 18, 20-2, 25,
27-8, 65, 303, 305, 312, 338
Coralberry, 327
Cord-grass, prairie, 326
Coreidae, 316, 339
Corixa, 296, 299, 303, 305, 307, 309, 312-3, 316,
319-20, 322
Corixidae, 13, 296, 299, 316, 319, 338
Cormorant, 176
Corn, 113-4, 117, 150-1, 160, 177, 192, 195,
199-200, 247-9, 269, 282, 289, 293-5, 298,
300, 304, 306, 308, 311, 313-5, 321, 323-4,
327-8, 343, 348, 350
broom, 151
field, 112
Indian, 204
sweet, 112-3
Cornus, 325
Corydalis cornuta, 296
Cotton, 118
Cottontail, see Rabbit (cottontail)
Cottonwood, 148
Cow, 120
1526, 18» 20-2,
+78 Intinois NaturAL History Survey BULLETIN
Cowbird, 186
Cowpea, 151, 325
Crab-grass, 309-10, 326
smooth, 309, 326
Crapp.e, 164, 171, 379
black, 5, 172-3
white, 5, 172-3
Crataegus, 326; see also Hawthorn and Haw
Crayash, 14-5, 21-3, 24-5, 27-30, 51-2, 77, 296,
316, 340
Cricket, 69
‘rop, 143, 151, 158
cereal, 113, 117, 123-4, 160
economic, 148, 159-60
field, 149, 352
[fish], 376-7, 379-80, 383
tioricultural, 158-60
forage, 113, 123-4, 148, 160
fruit, 113, 123, 147, 149, 160
grain, 148, 160
ornamental, 159-60
pasture, 160
vegetable, 113, 147, 160
Crow, 186
Crustacea (crustacean), 130, 133-4, 137, 163,
261, 296, 299, 301, 303, 305-9, 312, 316,
319, 338-40
Cucumber, 151
Culicidae, 13
Curculio, plum, 104, 106-8
Curculionidae, 297, 300, 316, 320, 339
Currant, 151-2
Cuscuta, 327
Cutworm, 115, 117, 123
Cyclops, 12, 305
Cyclorrhapha, 309
Cyperus
erythrorhizos, 294, 298, 302, 304, 311, 318,
32344, 332; see also Nut-grass, red-rooted
esculentus, 247, 294, 298, 302, 304, 311, 318,
323-4, 335; see also Chufa
ferax, 304, 324
lancastriensis, 153
strigosus, 294, 298, 302, 304, 311, 323-4, 334;
see also Nut-grass
Cypress (tree), 349
Cyprinus
carpio, 5; see also Carp
coronarius, 1
Cypris, 305
Cytosporina, 155
~~
D
Damselfly, 14-5, 22-6, 28-30, 52, 77, 139, 296,
299, 305, 338
Daphnia, 12
Darter, Johnny, 5, 74
Daucus pusillus, 153
Decapoda (decapod), 12, 14-6, 18, 20-2, 296
Deer, 197-8
red, 129
Deer’s tongue, 332
Dendrocygna
autumnalis, 394
bicolor, 394
Deutzia, 151
Dewberry, northern, 327
Diabrotica, 307
undecimpunctata howardi, 300,305, 313
Volume 27
Dickcissel, 184
Dicliptera brachiata, 153
Digitaria
ischaemum, 309, 326
sanguinalts, 309, 326; see also Crab-grass
Diodia teres, 327
Diptera (dipteran), 13, 15-6, 18, 20-2, 24-6,
28-30, 51-2, 135, 139-40, 142, 297, 300, 303,
305, 307, 309, 312, 316, 319-20, 322, 339
Dobsonfly, 140
Dock, pale, 325
Dodder, 327
Dog
domestic, 196
hunting, 199
Dogwood, 313, 325
Dolomedes triton sexpunctatus, 12
Dorosoma cepedianum, 5, 340; see also Shad,
gizzard
Dothiorella quercina, 156
Dothiorella wilt fungus, 155
Dove, mourning, 194-5, 199
Draeculacephala, 307
Dragontly, 15, 22-5, 28-30, 52, 77, 139, 296, 299,
305, 307, 316, 338
Dryopidae, 320, 339
Duck, 111, 177, 191-4, 196, 199, 239, 242-50,
252-73, 275-6, 278-80, 282-3, 284-6, 289-
343, 391-470
baldpate, 247, 254, 258-62, 264-6, 282, 284,
291, 293, 306-8, 327, 330, 341-3, 404-7, 410-
4, 416-7, 420-3, 425-8, 438-9, 447-8, 458,
470
black, 193, 242, 257-65, 267-8, 285, 289, 291,
293, 314-5, 340-1, 343, 394, 396-7, 399-401,
406-8, 421, 435-7, 447, 466, 470
black-bellied tree, 394
blue-winged teal, 193-4, 247, 253-60, 264, 282,
284, 291, 293, 301-5, 311, 332, 334-5, 337,
341, 343, 393-4, 398, 403-4, 406-7, 412-4,
416-8, 420-2, 425, 427-8, 437-8, 466, 470
bufflehead, 259-61, 284
canvasback, 238, 247, 257, 259-65, 267-9, 282,
285, 291, 293, 320-1, 341, 343, 394, 400,
403-9, 412, 414, 416, 420-1, 426-8, 438, 466,
468, 470
cinnamon teal, 247, 412
common goldeneye, 247, 254, 259-61, 284, 291,
323, 341-3
fulvous tree, 394
gadwall, 247, 254, 258-62, 264-6, 282, 284,
291, 293, 308-10, 327, 330, 341-3, 394,
403-8, 411-3, 416-7, 420-2, 425, 427-30,
438, 448, 458, 466, 468, 470
greater scaup, 238, 246-7, 291, 323, 341, 343
green-winged teal, 241, 247, 253, 258-61,
263-6, 284, 291, 293, 303-6, 311, 331-2,
334-5, 337, 341, 343, 394, 403-9, 411-3,
416, 419-23, 425, 428-9, 438-9, 443, 448,
466, 468, 470
lesser scaup, 239, 241, 254, 256-61, 263-5,
267-9, 282, 285, 291, 293, 315-7, 337, 341-3,
393, 402-8, 412-4, 416-7, 419-21, 426-8,
438, 447, 466, 470
mallard, 191-4, 196, 236-50, 254-62, 264-86,
289, 291-7, 300-3, 307, 313, 315, 327-8,
330-1, 333, 335, 340-3, 393-401, 403-70
merganser, 259-61, 284
Mexican, 394
1957-1961
mottled, 394
oldsquaw, 291, 323, 341, 343
pintail (American), 196, 238-41, 244, 247,
253-62, 264-9, 281-2, 284-5, 291, 293, 297-
a4 307=8, 32728, 35122, 333—5, 337, 341-3,
393, 402-23, 425-9, 438-9, 442-4, 447-8,
454-6, 462-3, 466, 468-70
redhead, 241, 254, 257-69, 282, 285, 291, 293,
321-2, 327, 341-3, 394, 400, 402-4, 406-3,
410-4, 416, 421, 426-8, 438-9, 447, 466, 468,
470
ring-necked, 254, 259-61, 263-5, 267-9, 282,
285, 291, 293, 317-9, 327, 330, 337, 341-3,
393, 405-8, 412-4, 427-9, 466, 468, 470
ruddy, 247, 259-60, 284, 291, 322, 341, 343,
408, 414, 420, 427-8
shoveler, 244-5, 247, 253, 258-61, 263-5, 282,
284, 291, 293, 310-2, 332, 337, 341-3, 394,
403, 406-14, 416, 421-2, 425-8, 437-9, 443,
448, 466, 470
teal, 308, 333, 342
wood, 103, 192, 196, 254-6, 259-61, 264, 282,
284, 291, 293, 312—4, 327, 341, 343, 394,
402-3, 405, 466
Duck-potato, 193, 292, 294-5, 298, 300, 304, 306,
318, 320-1; 323-4, 336-7, 343
Duckweed, 300, 308, 310
lesser, 298, 302, 304-6, 324
Dytiscidae, 13, 296, 299, 305, 307, 309, 312, 314,
316, 319-20, 322, 339
E
Earthworm, 69, 133, 137, 356
Earworm, corn, 111-3
Echinochloa
crusgalli, 294, 298, 302, 304, 309, 311, 313-4,
321, 323-4, 330-1; see also Millet, wild
frumentacea, 330; see also Millet, Japanese
waltert, 294, 298, 302, 304, 311, 323-4, 335;
see also Millet, Walter’s
Ectoparasite, 132, 197
Eel, American, 5
Egg plant, 111
Elateridae, 13
Elderberry, 117
Eleocharis
obtusa, 325
palustris, 325
parvula, 325
Elk, 128
Elm, 118, 154-60
American, 155-6
Asiatic, 155
Chinese, 157
English, 157
slippery, 157
Elmidae, 297, 305, 339
Enallagma
basidens, 12
carunculatum, 12
civile, 12
signatum, 12
Entomostraca, 29-30, 65
Ephemeroptera, 12, 14-6, 18, 20-2, 141, 296,
299, 303, 305, 307, 312, 314, 316, 319-20,
322, 338
Epicordulia princeps, 12
Eragrostis hypnoides, 298, 302, 304, 311, 3234,
337; see also Grass, teal
INDEX 479
Erichloa villosa, 153
Erimyzon sucetta, 5
Eristalis, 13
Erythemis simplicicollis, 12
Esox vermiculatus, 5
Etheostoma nigrum, 5, 74
Evergreen, 146
F
Fagopyrum sagittatum, 325
Field-bindweed, 327
Fir
balsam, 146
silver, 146
Fish, 1-79, 96, 103, 129-31, 134-6, 163-4,
166-78, 206, 210, 261, 297, 300-1, 319,
539-40. 342. 345. 350. 355)-955=6- 363-5,
367-8, 372, 375-7, 379-81, 384, 386-8
white, 170
Flagellate, 27
Flea, 104
water, 340
Flower, 146
wild, 153, 206
Fluke, strigeid, 65; see also Posthodiplostomum
minimum
Flumnicola, 296, 316, 319-20, 338
Fly, 119-20, 139, 339, 356
black, 119
buffalo, 119
flower, 135
hessian, 104, 114-5, 117, 122
horn, 120
horse, 119-20, 297, 339
house, 119-20
ichneumon, 300, 305, 319
lace-winged, 121
stable, 120, 123
Syrphus, 121
Tachinid, 123
two-winged, 111
Fog-fruit, 325
Folder, lesser apple-leaf, 105
Formicidae, 13, 297, 300, 305, 316, 339
Fowl, domestic, 111
Fox, red, 196
Foxtail
green, 326
yellow, 326
Frog, 297, 339-40
Fruit, 106-10, 113, 123, 148, 151, 261
grain, 146
Fulica americana, 261
Fundulus
diaphanus, 5
notatus, 5
Fungus (fungi), 121, 147-9, 151-3, 156-7,
160—2, 170-1
bracket, 161
Dothiorella wilt, 155
G
Galliformes, 191
Gammarid, 319
Gammarus, 296, 299, 305
fasciatus, 319
Gar, short-nosed, 176
Gardenia, 158
Gastropoda (gastropod), 12, 16, 18, 20-2, 26,
480 Ittinois NaturAL History SurvEY BULLETIN
Gastropoda (gastropod )—continued
296, 299, 303, 305, 307, 312, 316, 319-20,
338
Geotrupes, 307
Geranium, 158
Gerbera, 158
Gerridae, 13, 296, 316, 338
Gerris, 13
remigis, 316
Geum, 327
Gladiolus, 158-60, 162
Goggle-eye, 1
Goldenrain (tree), 157
Goldfish, 173
Gomphus notatus, 296
Goose, 238, 259-60, 428, 431
American brant, 260
blue, 241, 244, 246-7, 259-60, 282, 284
Canada, 190-1, 239-40, 243, 246-7, 257-60,
284, 425, 428, 431
lesser snow, 244
snow, 241, 246-7, 259-60, 252, 284
white-fronted, 247, 260
Gooseberry, 152
ornamental, 151
Goshawk, 186
Grackle, 186
Grain, 123, 149
small, 117, 150, 160
Gramineae, 326
Grape, 107, 152
frost, 313, 326
Grass, 115, 117, 146, 188
barnyard, 295, 331
corn, 335
eel, 336
Hungarian, 114
old-witch, 326
prairie, 113, 117
teal, 298, 300, 302, 304-5, 311, 323-4, 336-7,
343
wild, 117
Grasshopper, 69, 105, 114-5, 117, 121, 123, 299,
305, 313
Grouse, ruffed, 467
Grub, 69
white, 114, 117, 121, 159, 162
Gyraulus, 338
parvus, 12, 299, 303, 305, 307, 312, 316
Gyrinidae, 296, 305, 312, 319, 339
H
Hackberry, 160, 326
Haliplidae, 13, 296, 299, 339
Haliplus, 13
Haplopappus ciliatus, 153
Haw, 107; see also Hawthorn and Crataegus
Hawk, 186
Cooper’s, 186
duck, 186
pigeon, 186
sharp-shinned, 186
Hawthorn, 157-8, 326; see also Haw
Hay, 425
Helianthus angustifolius, 153
Heliotropium tenellum, 153
Helisoma, 338
trivolvis, 296, 299
Hellgrammite, 296, 338
Volume 27
Helminth, 191
Hemerobius, 121
Hemiptera, 13, 16, 18, 21-2, 29, 296, 299, 303,
305, 307, 309, 312-3, 316, 319-20, 322, 33.
Heron, great blue, 65
Herring, 36
Heteranthera dubia, 309, 325; see also Mud-
plantain
Hexagenia, 296, 299, 303, 305, 307, 312, 314,
316, 319-20, 322, 338, 340
limbata, 12, 14
Hibiscus militaris, 326
Hog, 107-8
Hollyhock, 158
Homoptera, 13, 22, 296, 307, 338
Honeysuckle, bush, 151
Hornwort, 330
Horse, 119-20
Horsechestnut, 158
Hyalella azteca, 12
Hydracarina, 300, 303, 305, 307, 309, 312, 319,
322
Hydrachnellae (on one page misspelled Hy-
drochnellae), 12, 18, 20, 22
Hydrangea, 158
Hydrophilidae, 13, 296, 299, 307, 314, 316, 339
Hydro porus, 13
Hydropsyche, 297, 300
Hydropsychidae, 142, 297, 300, 339
Hydroptilidae, 13, 15, 142, 297, 300, 303, 305,
309, 312, 316, 339
Hymenoptera, 13, 16, 18, 21-2, 29, 144, 297, 300,
305, 316, 319, 339
I
Ichneumonidae (ichneumon), 300, 305, 319, 339
Ictalurus
melas, 5; see also Bullhead, black
natalis, 5; see also Bullhead, yellow
punctatus, 5; see also Catfish, channel
Illinobdella moorei, 66, 78
Tlybius, 13
Insect (see also Insecta), 51, 89, 91, 102, 104-7,
109, 112-4, 117-25, 129-30, 132, 134-5,
137-8, 139-40, 143, 210, 261, 319
aquatic, 163
scale, 108, 118
Insecta (see also Insect), 296, 299, 303, 305,
307, 309, 312-4, 316, 319-20, 322, 338, 340
Ipomea hederacea, 326
Iris, 151, 158
Ischnura
posita, 12
verticalis, 12
Isopoda (isopod), 12, 15-6, 18, 20-2, 25, 28,
296, 299, 305
Ivy, 158
poison, 326
Juncus, 304, 325
Juniper, 118, 157
Irish, 146
savin, 146
Swedish, 146
Jussiaea leptocarpa, 153
K
Killifish, banded, 5
=e
1957-1961
Kinglets, 183
Knotweed, prostrate, 324
L
Labidesthes sicculus, 5
Ladybug, 121
Lady’s thumb, 294, 298, 304, 324
water, 294, 298, 324
Lamb’s-quarters, 325
Lamprey, 177
Leafhopper, 123, 135, 141-2, 296, 307, 338
potato, 112
Leafworm, cotton, 104
Leech, 66, 78, 137, 163
Leersia oryzoides, 294, 298, 302, 304, 306, 309,
313-4, 323-4, 328; see also Rice cut-grass
Leguminosae (legumes), 118, 326
Lemna minor, 298, 302, 304, 306, 324; see also
Duckweed, lesser
Lepidoptera, 135, 143, 297, 309, 322, 339
Lepomis, 67
cyanellus, 5; see also Sunfish, green
gibbosus, 5; see also Pumpkinseed
humilis, 5
macrochirus, 5, 13, 178, 345; see also Bluegill
megalotis, 5; see also Sunfish, longear
microlophus, 177; see also Sunfish, redear
Leptorhynchoides thecatus, 66
Lespedeza, 151
Leucorrhinia, 12
Libellula pulchella, 12
Lichens, 146, 161
Lily, 151, 158
water, 146
Limnesia fulgida, 12
Linden, 157
Lioplax, 338
subcarinata, 316
subglobosus, 299
Lippia lanceolata, 325
Liverworts, 146, 161
Livestock, 119-20, 123
Lixus, 300
Locust, 105, 114
17-year, 118
Locust [tree], black, 147, 157
Logperch, 5
Lophotocarpus (lophotocarpus), 292, 326
Lotus, 313, 334
American, 292, 311, 325
Louse, 123
apple-root plant, 107
bark, 105, 107, 118
melon, 111
plant, 121
Luperina stipata, 117; see also Cutworm
Lycosidae, 12
Lydella stabulans grisescens, 123
Lygaeidae, 296, 299, 338
Lygaeus, 296
kalmii, 299
Lygus, 338
lineolaris, 299, 307
Lymnaeidae, 12
M
Macrocentrus ancylivorus, 122
Macropus leucopterus, 117
Madtom, 5
INDEX 481
Magdallis armicollis, 154
Maggot, 111
Magnolia, 157
Magpie, 128
Malacostraca, 296, 299, 305, 338, 340
Mallard, see Duck, mallard
Mammal, 129, 136, 182, 195-6, 198-9, 206, 210,
283
furbearing (furbearer), 177, 195-6, 199
game, 197
Man, 119, 125
Maple, 148, 157-8
hard, 160
Mareca americana, 247, 307; see also Duck,
baldpate
Mastodon, 129
Mayfly, 14, 22-30, 52, 77, 135, 141-2, 296, 299,
303, 305, 307, 312, 314, 316-7, 319-20, 322,
338, 340
Meadowlark, 179, 183
Medicago arabica, 153
Megaloptera, 13, 140
Melanotus, 13
Membracidae, 13
Mergus, 259; see also Duck, merganser
Microcaddisfly, 142
Microfilaria, 191
Microlepidoptera, 144
Micropterus
dolomieui, 5, 175; see also Bass, smallmouth
punctulatus, 5
salmoides, 5, 13, 345; see also Bass, large-
mouth
Microvelia, 13
Midge, 28, 139, 297, 300-1, 303, 305-7, 309-10,
312, 316, 319-20, 322-3, 339-40
wheat, 114—5, 122
Millet, 193, 246, 300
German, 326
Japanese, 292, 330
Walter’s 292, 294, 298, 302, 304, 311, 323-4,
335-6, 343
wild, 292, 294-5, 298, 302, 304, 309-11, 313-4,
321-4, 330-1, 336, 343
Mimidae, 183
Mink, 195, 198-9, 425
Minnow, 30, 49, 69, 72-4, 76, 172, 175, 356
bluntnose, 5
bullhead, 73
fathead, 5, 74
Minytrema melanops, 5
Miridae (mirid), 135, 140, 142, 299, 338
Mite, 111, 119, 133, 157
orobatid, 137
water, 297, 300-1, 303, 305, 307, 309, 312, 319,
322, 339-40
Mold, 161
slime, 161
Mole, 195
Mollusca (mollusc, mollusk), 128, 134, 296, 299,
303, 305-9, 312, 314, 316-7, 319-20, 338-40
Morning-glory, ivy-leaved, 326
Mosquito, 27, 119-20, 139
Moss, 146, 161
Moth, 130, 143-4, 309
clothes, 123
codling, 104, 102-10, 123-4
cutworm, 297
gypsy, 118
482 Intinois Natura History Survey BULLETIN
Moth—continued
oriental fruit, 104, 108, 122
Mouse, 200
Moxostoma
anisurum, §
aureolum, §
Mud-plantain, 309-10, 325
Mulberry, 151
Mule, 119
Musculium, 338, 340
transversum, 296, 299, 316, 319
Mushroom, 147, 161
Muskrat, 195-6, 198, 342, 463
Mussel, 170, 296-7, 299, 303, 312, 314, 316,
319-20, 338-9, 343
Myriophyllum heterophyllum, 325
N
Naiad
northern, 325
southern, 325
Najas
flexilis, 325
guadalupensis, 325
Nectarine, 107
Nelumbo lutea, 311, 325; see also Lotus, Ameri-
can
Nematode, 65, 150, 161
Neoconocephalus, 299
Neodiprion sertifer, 122
Nepidae, 13, 296, 299, 338
Neritina, 316-7, 338, 340
Nettle, horse, 111
Neuroptera, 13, 16, 20, 22, 296, 338
Nightshade, 326
Noctuidae, 297
Notemigonus crysoleucas, 5; see also Shiner,
golden
Notonecta, 296
Notonectidae, 13, 296, 338
Notropis volucellus volucellus, 30
Noturus, 5
Nut-grass, 193, 294, 298, 300, 302, 304, 311, 324,
334, 343
red-rooted, 294, 298, 302, 304, 311, 318, 323-4,
332, 334, 343
Nymphaea tuberosa, 325
O
Oak, 118, 145-6, 156-8, 160
blackjack, 147
pin, 148, 191, 313, 325
white, 325
Oats, 114, 151, 199, 327
Odonata, 12, 14, 29, 139, 296, 299, 305-7, 316,
338, 340
Oecetis
cinerascens, 13
inconspicua, 13
Oligochaeta, 12
Olor
buccinator, 239; see also Swan, trumpeter
columbianus, 238; see also Swan, whistling
Omophron, 307, 339
Onion, 111
Orange, osage, 183
Orchid, 158
Orconectes
propinquus propinquus, 12
Volume 2?
virilis, 12
Organism, 171, 200
animal, 261
aquatic, 163, 169, 178
Orthoptera, 94, 133, 137, 299, 305, 313, 338
Orthorrhapha, 309
Orthotrichia, 13
Ostrocoda (ostracod), 12, 15-6, 18, 20-1, 25-7,
30, 296, 299, 303, 305, 309, 312, 338, 340
Owl, 186
great horned, 186
Oxyethira, 13
Oxyura jamaicensis, 247, 322; see also Duck,
ruddy
P
Pachydiplax longipennis, 12
Paddlefish, 174
Palaemonetes paludosa, 30
Panic-grass, fall, 302, 326
Panicum
capillare, 326
dichotomiflorum, 302, 326
Parasite, 144, 149, 187, 189, 191
blood, 195
helminth, 188, 191, 195
oriental fruit moth, 122
Parsnip, 111
Partridge-pea, 326
Paspalum, ciliate-leaved, 326
Paspalum ciliatifolium, 326
Pea, 152
sweet, 158-9
Peach, 106-8, 122, 149, 151-2
Pear, 106, 108, 147, 151-2
Pecan, 151, 191
Pectinatella, 340
Pelecypoda, 296, 299, 303, 305, 312, 314, 316,
319-20, 338
Peltodytes, 13, 29
Pentatomidae, 296, 339
Pentatomoidea, 139
Peony, 158-9
Peperomia, 158-9
Pepper, 151-2, 161
Perca flavescens, 5
Perch, yellow, 5
Percina caprodes, 5
Perithemis tenera, 12
Periwinkle, 158
Petunia, 158
Phalangid, 134, 137
Phaseolus, 326
Phasianus colchicus, 425; see also Pheasant
Pheasant, 187-8, 190, 198, 425
ring-necked, 189-90, 341, 464
Phoma, 155
Phryganeidae (on one page misspelled Phyr-
ganeidae), 13, 15
Phyllophaga futilis, 13, 143
Phyllotreta, 13
Physa, 65, 296, 307, 319, 338
gyrina, 12, 299, 305
integra, 12
Physidae, 12
Phytolacca americana, 327
Pickerel, grass, 5
Pickerelweed, 292
heart-shaped, 326
1957-1961
Pigeon, wild, 128
Pigweed, 332-3
Pike
northern, 164
wall-eyed, 170
Pillbug, 340
Pimephales
notatus, 5
promelas, 5, 74
vigilax, 73
Pine, 157, 161, 349
Araucarian, 146
Austrian, 146
Himalayan, 146
red, 160
Scotch, 146
white, 146, 160
Pintail, see Duck, pintail (American)
Pisauridae, 12
Pisces, 13-6, 18, 21-2, 297, 300, 319-20,
339-40
Pisidium, 296, 299, 303, 312, 316, 319, 338,
340
Plankton, 137, 147, 166-71, 184
Planorbidae, 12
Planorbis, 296, 299, 338
Plant, 129, 145-7, 151-4, 159-63, 178, 210, 261,
343
aquatic, 166, 193, 261, 358
crop, 147, 149
drug, 154
evergreen, 146
floricultural, 158
marsh, 193
moist-soil, 193, 300-1, 308, 310, 318, 327,
331-2, 337, 343
ornamental, 118—9, 148-9, 158, 162
wild, 195, 329, 343
Plant disease collection, 152
Plant disease survey, 149
Plant foods [of waterfowl], 154, 193, 292-5,
298, 300-15, 317-37, 343
Plant-louse, cabbage, 111
Plathemts lydia, 13
Plecoptera, 139-40, 142
Pleurocera, 296, 316, 319, 338, 340
Plum, 106-7, 152
Plumatella, 12, 340
Podura aquatica, 12
Poinsettia, 158
Pokeweed, common, 327
Polygonum
amphibium, 294, 298, 324
aviculare, 324
coccineum, 294, 298, 302, 304, 306, 309, 311,
313-4, 318, 321, 323-4, 329; see also Smart-
weed, marsh
hydropiper, 294, 298, 304, 318, 324
hydro piperoides, 294, 298, 306, 313, 324; see
also Smartweed, swamp
lapathifolium, 294, 298, 302, 304, 306, 309,
311, 318, 321, 323-4, 333; see also Smart-
weed, nodding
pensylvanicum, 294, 298, 302, 304, 306, 309,
311, 318, 321, 323-4, 334; see also Smart-
weed, large-seeded
persicaria, 294, 298, 304, 324
punctatum, 294, 298, 302, 304, 306, 311, 318,
321, 324
INDEX 483
sagittatum, 294; see also Tearthumb, arrow-
leaved
scandens, 294, 324
Polyodon spathula, 174
Pondweed, 193, 306, 317
horned, 326
large-leaved, 294, 324
leafy, 294, 298, 304, 306, 315, 318, 320, 322,
324
longleaf, 294, 298, 300, 302, 304, 306, 309-11,
313-5, 318, 320-4, 331-2, 343
ribbon-leaf, 302, 304, 324
sago, 294, 298, 301-2, 304, 306, 311, 313-5,
318, 320-1, 323-4, 336, 343
small, 294, 298, 304, 314—-5, 318, 320, 324
thoroughwort, 294, 324
white-stem, 294, 318, 324
variable-leaf, 318, 324
Pomoxis
annularis, 5; see also Crappie, white
nigromaculatus, 5; see also Crappie, black
Pontederia cordata, 326
Poplar, 157
Portulaca, 327
Posthodiplostomum minimum, 65-6, 78
Potamogeton, 358
am plifolius, 294, 324
epihydrus, 302, 304, 324
foliosus, 72, 294, 298, 304, 306, 315, 318, 320,
324; see also Pondweed, leafy
gramineus, 318, 324
nodosus, 294, 298, 302, 304, 306, 309, 311,
313-5, 318, 320-1, 323-4, 331-2,; see also
Pondweed, longleaf
pectinatus, 294, 298, 302, 304, 306, 311, 313-5,
318, 320-1, 323-4, 336; see also Pondweed,
sago
perfoliatus, 294, 324
praelongus, 294, 318, 324
pusillus, 294, 298, 304, 314-5, 318, 320,
324
Potato
Irish, 111-2, 123, 152
wild, 111
Potentilla, 326
Poultry, 112, 119
Probythinella binneyana, 316, 319
Procambarus blandingti acutus, 12
Proteocephalidae, 12
Proteocephalus ambloplites, 65-6, 78
Protozoa (protozoan), 27, 77, 122, 134, 137,
163, 166, 191
Prunus, 327; see also Plum
americana, 107
domestica, 107
Pseudoscorpion, 134, 137
Psocid, 135
Pumpkinseed, 5, 10, 39, 62
Purslane, 327
Pylodictis olivaris, 5
Q
Quail, 188-9, 198
bobwhite, 187-8, 199, 341
Quercus
alba, 325
palustris, 313, 325; see also Oak, pin
Quince, 108
Japanese, 160
484 Inuinois Narurat History Survey BULLETIN
R
Rabbit (cottontail), 197-9
Raccoon, 192, 196, 425
Ragweed
common, 321, 325
giant, 117
great, 325
western, 325
Ranatra, 13, 296, 299
Ranunculus, 325
Raspberry, 152
Rat, Norway, 104
Red top, 151
Redbud, 157
Redhorse
northern, 5
silver, 5
Redtop (marsh smartweed), 329
Reptile, 103, 134, 136, 210
Rhagovelia, 13
Rhaphidophorinae, 313
Rhizoclonium, 357
Rhubarb, 151
Rhus
glabra, 326
radicans, 326
Rice, 178, 239
Rice cut-grass, 193, 294-5, 298, 300, 302, 304,
306, 309-10, 313-4, 323-4, 328, 343
Roccus mississippiensis, 5
Rosa, 327
Rose, 158-9, 327
multiflora, 157, 188
Rose-mallow, scarlet, 326
Rotifer, 137, 163, 166
Rubus flagellaris, 327
Rudbeckia missouriensis, 153
Rumex
acetosella, 325
altissimus, 325
Rush, bog, 304, 325
Rye, 114, 348
S
Sagittaria
cuneata, 294, 324; see also Wapato
latifolia, 294, 298, 304, 306, 318, 320, 323-4,
336-7; see also Duck-potato
Salix, 325
Saperda tridentata, 154
Saw-fly, 135, 144
currant, 105
pine, 122
Saw-grass, 328
Scale, San Jose, 97, 104, 109-11
Scarabaeidae, 13, 297, 299, 307, 309, 312, 316,
319, 339
Scirpus
acutus, 309, 318, 325
americanus, 325; see also Bulrush, American
atrovirens, 325
fluviatilis, 309, 318, 321, 323, 325,337: see
also Bulrush, river
paludosus, 325; see also Bulrush, alkali
validus, 309, 318, 321, 325; see also Bulrush,
soft-stem
Screwworm, 123
Scud, 30
Sedge, beaked, 326
Voitume 27
Setaria
faberti, 153
glauca, 326
italica, 326
viridis, 326
Shad, gizzard, 4-6, 172-3, 340
Sheep, 109
Shiner
golden, 5, 173, 176
northern mimic, 30
Shrimp, 30
fairy, 305
Shrub, 104, 145, 153, 157, 159-60, 206
Sialidae, 13
Sialis, 13
Sida, prickly, 326
Sida spinosa, 326
Silverside, brook, 5
Simocephalus, 12, 28
Simulium, 119
Siphlonurus, 12, 14, 26-9
Sisyridae, 13
Skunk, 424
Smartweed, 193, 246
dotted, 294, 298, 302, 304, 306, 311, 318, 321,
324
large-seeded, 292, 294, 298, 302, 304, 306, 309,
311, 318, 321, 323-4, 333, 334, 343
marsh, 292, 294-5, 298, 300, 302, 304-6, 309-
11, 313-4, 318, 321, 323-4, 329-30, 334, 343
nodding, 292, 294, 298, 300, 302, 304, 306, 309,
311, 318, 321, 323-4, 333, 343
Pennsylvania, 334; see also Smartweed,
large-seeded
swamp, 292; see also Polygonum hydropiper-
oides or Water-pepper, mild
Snail, 25, 27, 30, 65, 296-7, 299, 303, 305-7, 312,
316-7, 319-20, 323, 338-9, 343
fresh-water, 340
land, 137, 206
water, 317
Snapdragon, 158
Snout-beetle, reddish elm, 154
Solanum, 326
Somatogyrus, 338
subglosus, 316, 319
Sorghum, 114, 327
Sorghum vulgare, 327
Sorrel, field, 325
Soybean, 151
Sparganium eurycarpum, 318, 323, 325, 337;
see also Bur-reed, giant
Sparrow, English, 183
Spartina pectinata, 326
Spatula clypeata, 247, 310, 394; see also Duck,
shoveler
Specularia biflora, 153
Sphaeriidae, 296, 299, 316, 319, 338
Sphaerium, 296, 299, 303, 305, 319-20, 338, 340
stamineum, 316
Spider, 300, 316, 319, 322, 340
Spike-rush
blunt, 325
common, 325
dwarf, 325
Spindleworm, 117
Spittlebug, 123
Springtail, 135, 144
Spruce, 157
1957-1961
black, 146
Douglas, 146
Norway, 146, 160
red, 146
Squash, 151
Squirrel, 157
fox, 192, 197-8, 425, 467
gray, 197
Stagnicola, 296, 319, 338
Staphylinidae, 296, 299, 305, 312, 339
Stevia, 158
Stock, 158
Stonefly, 100, 135, 139-40, 142
Stratiomyidae, 13
Strawberry, 107, 114, 152
Strophostyles helvola, 326
Sucker
spotted, 5
white, 5
Sumac
fragrant, 151, 160
smooth, 326
Sunfish, 1, 7, 15, 30, 39, 42, 48-9, 67, 74
green, 5, 47, 67-8, 74, 178, 354
longear, 5, 62
orangespotted, 5
redear, 74-5, 176-8
Sunflower, 118
Swan, 191
trumpeter, 239, 245, 247
whistling, 238-41, 243-6, 284
Swine, 109, 178
Sycamore, 148, 157-8
Sym petrum obtrusum, 13
Symphoricarpos orbiculatus, 327
Syrphidae, 13
T
Tabanidae (tabanid), 13, 120, 123, 297, 320,
339
T abanus, 119-20, 320
Tadpole, 30
Tamarack, 161
Tapeworm, 39, 187
bass, 65; see also Proteocephalus ambloplites
Tearthumb, arrow-leaved, 294, 324
T etragoneuria, 13
Tettigoniidae, 305
Thistle, Canada, 147
Thrips, 135, 143
Thysanoptera, 143
Tick, 119, 123, 133-4, 197
Timothy, 114, 117, 151
Tiphia, 297, 300, 339
Tiphiidae, 297, 300, 339
Tomato, 152
Tooth-cup, 327
Topminnow, blackstripe, 5
Tortrix malivorana, 105
Tree, 104, 107, 118-9, 149, 153-5, 157, 159-60,
188, 191, 206; see also individual
Species
forest, 147-8, 154
roadside, 147
shade, 154
street, 147
Trichoptera, 13-6, 18, 20-2, 142, 297, 300, 305,
307, 309, 312, 314, 316, 319, 322, 339
Trifolium, 327
INDEX 485
Triticum aestivum, 294, 324; see also Wheat
Tropisternus, 13
Trout, 170, 357
salmon, 170
Tubercularia ulmi, 155
Tuberose, 158
Tubulifera, 143
Tulip, 158
Tupelo, 157
Turdidae, 183
Turkey, 111-12
Turnip, 111
Twig-rush, 326
Ulmus
parvifolia, 155
pumila, 155
Ulothrix zonata, 306
Unionidae, 296, 299, 338
Vv
Vegetable, 106, 111, 113, 123, 148
Veliidae, 13
Velvet-leaf, 326
Verbascum virgatum, 153
Verbena hastata, 326
Vervain, blue, 326
Vigna sinensis, 325; see also Cowpea
Vine, 146
Violet, 158-9
African, 158
Vitis cordifolia, 313, 326
Viviparus, 338
viviparus, 316, 319
Walleye, 164
Walnut, 158
Wapato, 294, 324, 337
Warbler, prothonotary, 186
Warmouth, 1-79, 174-6, 178
Wasp, tiphiid, 297, 339
Water boatman, 296, 299, 303, 305-10, 312-3,
316, 319-20, 322, 338, 340
Water strider, 296, 316, 338
Waterfowl, 191-4, 196, 198, 235-86, 289, 291,
332-3, 335, 340, 391-5, 422-4, 427-8, 430,
447-9, 456, 458, 462-70
Water-hemp, 292, 294, 298, 300, 302, 304, 306,
314, 323-4, 332-3, 343
Water-lily, yellow, 325
Watermelon, 151
Water-milfoil, 325
W ater-pepper, 294, 298, 304, 318, 324
mild, 294, 298, 306, 313, 324; see also Smart-
weed, swamp
Water-plantain, 325
Waterscorpion, 296, 299, 338
Waterweed, 326
Wayfaring [tree], 157
Webworm
burrowing, 117
sod, 117
Weeds, 145, 154, 188, 358
Weevil, 135
clover leaf, 118
red elm bark, 154
sweet clover, 118, 123
486 Ittinors NaturAL History Survey BULLETIN
Wheat, 113-5, 117, 122, 149-51, 178, 294, 324,
348, 350
Willow, 157, 325
Wireworm, 117-8
Wood duck, see Duck, wood
Woodchuck, 199
Worm, 68, 356
apple, 104, 107-9
aquatic, 166
cabbage, 113
catalpa, 356
joint, 114
parasitic, 297, 339
Y
Yellow-wood, 157
Yew
English, 146
Irish, 146
Z
Zannichellia palustris, 326
Zea mays, 294, 298, 304, 306, 311, 313-4, 321,
323-4, 327; see also Corn
Zinnia, 158
Zygopters, 12, 14-6, 18, 20-2, 29, 296, 299, 305,
33
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