eid eee a am oe ie ba SRE Oe Forte Baty be * xe a Re Seis Raed a Py bese ty RN Ns ee Ne Ae BFA k tn I Eg ag Ps mee. ie edn Ree Pe or ye se aa hence ty “hes pate e ae Hy Rhee at a fe tes ones rR ADs oe Akt ily ek pe Ss Agee Os Sa What ee F m8 ray Sea : fone onan fe re me ee Eg te thy Sa Brae Om Reerse rns he te ee “ ‘ : cyt F< PRP OD tee er 2 OES ws sees J FED BLS fase Be Ee. FE Lp FAM oP IAL (HBP Pree egg 6 EL i ae Fao & pep ts PPI a SE LIF ate oe ise “pap CIF. \ i 7 * = > 7, a ‘Op i Le: a i a A ry ge : : ; a | A 1a ea RY “| ee Sal z 2p are Th ILLINOIS NATURAL HISTORY SURVEY Bulletin Volume 28 1961-1963 MATU Ry) HisTopy SURVEY 2 0 i969 LIBPApy STATE OF ILLINOIS - DEPARTMENT OF REGISTRATION AND EDUCATION NATURAL HISTORY SURVEY DIVISION # cern Urbana, Illinois jie LIBRARY OF Whe OCT 27 19°4 UW wate OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION Sere URAL HISTORY SURVEY DIVISION ILLINOIS NATURAL HISTORY SURVEY Bulletin Volume 28 1961-1963 Printed by Authority of the State of Illinois IRS Ch. 127, Par. 58.12 URBANA, ILLINOIS STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION BOARD OF NATURAL RESOURCES AND CONSERVATION Wituam Syivester Wurre, Chairman; Tuomas Park, Ph.D., Biology; Water H. Newnouse, Ph.D., omy Rocer Avams, Ph.D., D.Sc., Chemistry; Rosert H. Anpverson, B.S.C.E., Engineering ; Cuaries E. Outmsrep, Ph. Forestry; W. L. Everitt, E.E., Ph.D., Representing the President of the University of Illinois; Deryre W. Morais, Ph.D., President of Southern Illinois University NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF Hartow B. Mirus, Ph.D., Chief Lois W. Beevie, Acting Assistant to the Chief Section of Economic Entomology Georce C. Decxer, Ph.D., Principal Scientist and Head J. H. Biccer, M.S., Entomologist L. L. Eneuisu, Ph.D., Entomologist W_H. Lucxmann, Ph.D., Entomologist Wiis N. Bruce, Ph.D., Entomologist ; Joun P. Kramer, Ph.D., Associate Entomologist _ Ricuarp J. Dysart, Ph.D., Associate Entomologist Ronatp H. Meyer, Ph.D., Assistant Entomologist Eart Stapevsacuer, B.S., Technical Assistant Josern V. Mappox, M.S., Technical Assistant AucustinE Oxonxwo, M.S., Technical Assistant Dannet McCouium, B.A., Technical Assistant Raymonp Stimson, B.S., Technical Assistant Davip Kennepy, Technical Assistant Sue E. Warkins, Junior Scientific Assistant H. B. Perry, Ph.D., Entomologist in Extension* ere Stevenson Moore, III, Ph.D., Associate Entomologist in Extension* ; Crarence E. Wuire, B.S., Technical Assistant in Exten- ston™ Costas Kousxotexas, M.S., Research Assistant* Amat C. Banerjee, M.S., Research Assistant* Hsu-suien Wane, M.S., Research Assistant* Jean G. Wirson, B.A., Research Assistant* Section of Wildlife Research Tuomas G. Scott, Ph.D., Wildlife Specialist and Head Ratew FE. Yeatrter, Ph.D., Wildlife Specialist F. C. Beutrose, B.S., Wildlife Specialist H. C. Hanson, Ph.D., Associate Wildlife Specialist Ricuarp R. Graser, Ph.D., Associate Wildlife Specialist Guen C. Sanverson, Ph.D., Associate Wildlife Specialist Ronatp F. Lanisxy, M.S., Associate Wildlife Specialist Marjorie J. Scurarrer, Technical Assistant Ricnuarp Barruotomew, B.S., Technical Assistant Howarp Crum, Jr., Field Assistant Jacx A. Exuis, M.S., Project Leader* Bossie Joe Verts, M.S., Project Leader* Rareu J. Exuis, M.S., Project Leader* Wittiam L. Anverson, B.S., Assistant Project Leader* Davin A. Casteer, B.S., Assistant Project Leader* Geratp G. Montcomery, M.S., Research Associate* Joun E. Warnock, Ph.D., Research Associate* Wituiam R. Epwarps, M.S., Research Associate* Gerorce B. Joseryn, M.S., Research Assistant* Ricuarp D. Anprews, M.S., Field Mammalogist* Geracp L. Storm, M.S., Field Ecologist* Terence R. Troucuron, B.S., Field Biologist* Daniet M. Cain, M.A., Laboratory Assistant* Keiru P. Daupnin, Assistant Laboratory Attendant* Section of Faunistic Surveys and Insect Identification H. H. Ross, Ph.D., Principal Scientist and Head Mitton W. Sanverson, Ph.D., Taxonomist Lewis J. Stannarp, Jr., Ph.D., Taxonomist Puivie W. Smiru, Ph.D., Taxonomist Leonora K. Gioyp, M.S., Assistant Taxonomist H. B. Cunnincuam, Ph.D., Assistant Taxonomist Ruru P. Casu, Technical Assistant Marvin E. Braascn, Laboratory Assistant Joun D. Unzicxer, B.S., Research 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. Borewe, M.S., Associate Plant Pathologist Rosert A. Evers, Ph.D., Associate Botanist Rosert Dan Neety, Ph.D., Associate Plant Pathologist E. B. Hime tick, Ph.D., Associate Plant Pathologist Wa crter Hartstirn, Ph.D., Assistant Plant Pathologist D. F. ScHoenewerss, Ph.D., Assistant Plant Pathologist Anne Rosrnson, M.A., Technical Assistant Section of Aquatic Biology Georce W. Bennett, Ph.D., Aquatic Biologist and Head WixuiaM C. Starrett, Ph.D., Aquatic Biologist R. W. Larimore, Ph.D., Aquatic Biologist Davin H. Buck, Ph.D., Associate Aquatic Biologist Rosert C. Hittipran, Ph.D., Associate Biochemist Donaup F. Hansen, Ph.D., Associate Aquatic Biologist Wituiam F. Cuiipers, M.S., Assistant Aquatic Biologist Micuaet G. Jounson, Biochemical Assistant Maryrran Martin, Technical Assistant Ropert D. Crompton, Field Assistant Micuaet J. Duever, Field Assistant Cuartes F. Tuorrts, III, A.B., Research Associate* Roti D. Anprews, III, B.S., Field Assistant* Larry Boum, Field Assistant* Section of Publications and Public Relations James S. Ayars, B.S., Technical Editor and Head Buancue P. Youne, B.A., Assistant Technical Editor Winer D. Zenr, Assistant Technical Photographer Technical Library Doris F. Dopvps, B.A., M.S.L.S., Technical Librarian Patricia F. Stenstrom, B.A., M.S.LS, Assistant Tech- nical Librarian CONSULTANTS: Herrerorocy, Hoparr M. Smiru, Ph.D., Professor of Zoology, University of Illinois; ParastroLocy, Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University of Illinois; Wirpuire Researcu, Wittarp D. Kuimstra, Ph.D., Professor of Zoology and Director of Co-operative Wildlife Re- search, Southern Illinois University; Sratistics, Horace W. Norton, Ph.D., Professor of Agricultural Statistical Design and Analysis, University of Illinois. _*Employed on co-operative projects with one of several agencies: University of Illinois, Illinois Agricultural Ex- tension Service, Illinois Department of Conservation, National Science Foundation, United States Department of Agri- culture, United States Fish and Wildlife Service, United States Public Health Service, and others. (88859—500—3-64) This page lists members of the staff as of August, 1963. CONTENTS ARTICLE 1—THE AMPHIBIANS AND REPTILES OF ILLINOIS. By Puitip W. SmirH. November, 1961. 298 pp., frontis., 252 figs., bibliog., index. . 1-298 Acknowledgments 1, Previous herpetological investigations 2, Illinois as a herpeto- faunal region 4, Presentation of data 14, Systematic account 15, Literature cited 274, Index 287 ARTICLE 2.—THE FISHES OF CHAMPAIGN COUNTY, ILLINOIS, AS AFFECTED BY 60 YEARS OF STREAM CHANGES. By R. WeELpon Larimore and Puitip W. SmitH. March, 1963. 84 pp., frontis., 70 figs., bibliog., “ALLELE os uah ete otek die eg SAW Capes EEL AL ea A eS oe a a 299-382 Acknowledgments 299, Methods and equipment 300, Description of county 306, Stream habitats 311, Annotated list of fishes 320, Analysis of distribution patterns 327, Changes in distribution 328, Ecological associations 335, General abundance and occurrence 339, Distribution and stream size 340, Distribution and pollution 346, Distribution and water enrichment 355, Fisheries 356, Summary 357, Literature cited 360, Species distribution maps 361, Index 376 ARTICLE 3—A COMPARATIVE STUDY OF BIRD POPULATIONS IN ILLINOIS, 1906-1909 AND 1956-1958. By RicHarp R. Graper and JEAN W. Graser. October, 1963. 146 pp., 4 frontis., 32 figs., bibliog., index...... 383-528 Methods 383, Weather patterns of census years 393, Bird populations in summer habi- tats 396, Bird populations in winter habitats 443, Account of species 458, Discussion 500, Literature cited 516, Index 519 EMENDATIONS Page 236, column 1, lines 26 and 35 of text matter; page 287, column 2, line 34 of index; page 297, column 2, line 12 of index. For annectans substitute annectens. Contents page at bottom, Volume 28, Article 3. Dr. Graber should have been identified as Asso- ciate Wildlife Specialist instead of Wildlife Associate. Because each article of Volume 28 has been indexed separately, an index for the entire volume has not been made. ILLINOIS NATURAL HISTORY SURVEY Bulletin Printed by Authority of Kg s the State of Illinois é\ The Amphibians and Reptiles of Illinois PHILIP W. SMITH STATE OF ILLINOIS Orro Kerner, Governor DEPARTMENT OF REGISTRATION AND EDUCATION WILLIAM SYLVESTER WHITE, Director NATURAL HISTORY SURVEY DIVISION Har.ow B. Mitts, Chief DEC2 4 spe ILLINOIS NATURAL HISTORY SURVEY Bulletin Volume 28, Article 1 Sas | Printed by Authority of November, 1961 the State of Illinois The Amphibians and Reptiles of Illinois eae bre W. SMITH mE Ate OF TLEINOTIS Otro KERNER, Governor DEPARTMENT OF REGISTRATION AND EDUCATION WILLIAM SyLvESTER WHITE, Director maeURAL HISTORY SURVEY DIVISION Hartow B. Mitts, Chief Urbana, Illinois SLA DS OF. 1 LELINO LS Orro Kerner, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Wivuram Syivester Wuire, Directo: BOARD OF NATURAL RESOURCES AND CONSERVATION Wiruiam Syivester Wuirte, Chairman; A. E. Emerson, Ph.D., Biology; Waiter H. Newnouse, Ph.D., Geology, Rocer Apams, Ph.D., D.Sc., Chemistry; Roserr H, Anverson, B.S.C.E., Engineering; W. L. Everett, E.E., Ph.D. Representing the President of the University of Illinois; Detyre W. Morris, Ph.D., President of Southern IIlinoi. University NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF Hartow B. Mirus, Ph.D., Chiet Bessie B. East, M.S., Assistant to the Chie} Section of Economic Entomology Georce C. Decxer, Ph.D., Principal Scientist and Head J. H. Biccer, M.S., Entomologist L. L. Eneuisu, Ph.D., Entomologist W. H. Lucxmann, Ph.D., Entomologist Writs N. Bruce, Ph.D., Entomologist Joun P. Kramer, Ph.D., Associate Entomologist Ricnarpv J. Dysart, Ph.D., Associate Entomologist Ronaip H. Meyer, M.S., Assistant Entomologist Recinatp Roperts, M.S., Technical Assistant James W. Sanrorp, B.S., Technical Assistant Earut STapeELBACHER, B.S., Technical Assistant Wiruiam C. Moye, M.S., Technical Assistant Sue E. Warxins, Technical Assistant H. B. Perry, Ph.D., Extension Specialist in Entomology* Stevenson Moore, III, Ph.D., Extension Specialist in Entomology* Zenas B. Noon, Jr., M.S., Research Assistant* Crarence E. Wuire, B.S., Instructor in Entomology Extension* Costas Kousxorexas, M.S., Research Assistant* Amat Cuanpra Baneryee, M.S., Research Assistant* Victor T. Wivuiams, B.S., Research Assistant* Section of Faunistic Surveys and Insect Identification H. H. Ross, Ph.D., Principal Scientist and Head Mirton W. Sanverson, Ph.D., Taxonomist Lewis J. Srannarp, Jr., Ph.D., Taxonomist Puitie W. Smiru, Ph.D., Associate Taxonomist Leonora K. Gioyp, M.S., Assistant Taxonomist H. B. Cunnincuam, M.S., Assistant Taxonomist Rutu P. Casn, Technical Assistant Wayne Becker, B.S., Research Assistant Joun M. Kincsotver, Ph.D., Research Associate* Joun D. Unzicxer, Research Assistant* Taraat K. Mirr:, M.S., Research Assistant* Section of Aquatic Biology Georce W. Bennett, Ph.D., Aquatic Biologist and Head Winuiam C. Starrett, Ph.D., Aquatic Biologist R. W. Larimore, Ph.D., Aquatic Biologist Daviw H. Buck, Ph.D., Associate Aquatic Biologist Rosert C. Hirtipran, Ph.D., Associate Biochemist Donaup F. Hansen, Ph.D., Associate Aquatic Biologist Wituiam F. Cuiivers, M.S., Assistant Aquatic Biologist Marirran Maxtin, Technical Assistant Rosert D. Crompton, Field Assistant Micuaer J. Duever, Field Assistant Rotuin D. Anprews, III, B.S., Field Assistant* Lesurr L. Layton, Field Assistant* Section of Aquatic Biology—continued Cuarces F. Tuorrs, III, A.B., Research Associate* 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. Boewe, M.S., Associate Plant Pathologist Ropert A. Evers, Ph.D., Associate Botanist Rosert Dan NeeEty, Ph.D., Associate Plant Pathologist E. B. Himexicx, Ph.D., Associate Plant Pathologist Water Hartstirn, Ph.D., Assistant Plant Pathologist D. F. Scooenewerss., Ph.D., Assistant Plant Pathologist AnNE Rosinson, M.A., Technical Assistant Section of Wildlife Research Tuomas G. Scott, Ph.D., Wildlife Specialist and Head Rautpuw E. Yeatrer, Ph.D., Wildlife Specialist F. C. Bevirose, B.S., Wildlife Specialist H. C. Hanson, Ph.D., Associate Wildlife Specialist Ricuarp R. Graser, Ph.D., associate Wildlife Specialist Ronatp F. Lapisxy, M.S., Associate Wildlife Specialist Gren C. Sanperson, M.A., Associate Wildlife Specialist Marjorie J. Scuuatrer, Technical Assistant D. G. Rose, B.S., Technical Assistant Howarp Crum, Jr., Field Assistant Rexrorp D. Lorn, D.Sc., Project Leader* Jacx A. Exxis, M.S., Project Leader* Bosnit Joe Verts, M.S., Project Leader* Rautpew J. Exvuis, M.S., Project Leader* Wiriiam L. Anverson, B.S., Assistant Project Leader* James A. Harper, M.S., Assistant Project Leader* Davin A. CasteEEL, B.S., Assistant Project Leader* Geratp G. Montcomery, M.S., Research Associate* P. J. Rao, B.V.Sc., M.A., Research Assisant* Ann C. V. Houmes, B.S.. Research Assistant* T. U. Meyers, B.S., Research. Assistant* Stuart H. Mann, B.S., Research Assistant* Ricuarp W. Lutz, M.W.M., Research Assistant* Ricuarp D. Anprews, M.S., Field Mammalogist* Kerry P. Daupnin, Assistant Laboratory Attendant* Section of Publications and Public Relations James S. Ayars, B.S., Technical Editor and Head Biancne P. Younc, B.A., Assistant Technical Editor Epwarp C. Visnow, M.A., Assistant Technical Editor Witmer D. Zeur, Assistant Technical Photographer Technical Library Rutu R. Warrick, B.S., B.S.L.S., Technical Librarian Barpara S. McCrimmon, B.S., M.S.L.S., Assistant Tech- nical Librarian CONSULTANTS: Herrerotocy, Horaxt M. Sairn, Ph.D., Professor of Zoology, University of Illinois; Parasiro.ocy, Norman D. Levine, Ph.D., Professor of Veterinary Parasitology and of Veterinary Research, University of Illinois; Witpiire Researcu, Witiaro D. Kurmstra, 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 Faunistic Surveys and Insect Identification. (08324—6M—10-60) aa oo 2 FOREWORD FOR THE BETTER PART of a century the Bulle- tin has published research reports on the ecol- ogy, biology, and taxonomy of the flora and fauna of Illinois. The present number is a worthy continuance of these scientific contri- butions. It was prepared under those legal charges to the Board of Natural Resources and Conservation, the agency which controls, guides, and governs the activities of the Natu- ral History Survey, to “conduct a_ natural history survey of the State giving preference to subjects of educational and economic im- portance,’ and “To publish, from time to time, reports covering the entire field of zool- ogy and botany of the State.” It is probable that no other groups of ani- mals have such staunch friends and adamant adversaries as do the amphibians and the reptiles, the subjects of this contribution. They are important to us in many ways, and, if they were not, “the characteristically human desire to investigate the unknown .. . provides an incentive to study them,” as the author of this paper states. We humans are likely to be selfish in our dealings with the so-called lower animals and to measure the worth of these animals only in terms of their economic elect upon us. We find that many amphibians and reptiles add materially to the well-being of people—some by the destruction of harmful insects and rodents, others by affording additions to our diet, as with frog legs or (to the adventurous palate) rattlesnake flesh. Those people with an aesthetic bent find in amphibians and reptiles a great deal of grace and beauty. Those interested in curious things find their inquisitiveness satisfied among ani- mals which have no legs, or which can change color, or which breathe largely through their skins, or which go through generation after generation without really growing up. Those who look for antiquity find that giant amphib- ians and reptiles developed, prospered, and passed on as living entities long before Nature began to experiment with the upright bipedal animals we call humans. Amphibians and reptiles are _ excellent organisms to study if one is interested in the variability of living things, as Dr. Philip W. Smith has amply demonstrated in this article. The movement of animals over the face of the earth in times past has intrigued biologists since the time of Aristotle. How did the pres- ent Illinois amphibians and reptiles reach the state? If they came from outside its limits, from what direction did they emigrate? What were the reasons for this movement? Illinois has proved to be a meeting place for many forms which apparently came from all directions, and many were unable to get past it or to invade it completely. Of the 94 species discussed here, only 25 are state-wide in their distribution. The other 69 have met limiting barriers somewhere in Illinois. For many species, parts of the state represent unin- habited islands, with the populations lapping at the shorelines on two, three, or four sides, but unable to overflow the highlands. For other species, parts of the state seem to repre- sent pools, small pockets of animals which cannot get out of circumscribed areas. The study on which the present report is based was initiated in June, 1947, and was one of the principal research projects of the Sec- tion of Faunistic Surveys and Insect Identifi- cation until June, 1953. The manuscript was completed in May, 1957, and was submitted for publication at that time. Budgetary reas- ons necessitated setting it aside until July, 1959. Although some revision has been neces- sary to bring the nomenclature and certain concepts up-to-date, the manuscript is approxi- mately the same as that submitted in May, 1957, and only the most pertinent of the recent literature has been incorporated. HarLtow B. Mitts, Chief Illinois Natural History Survey Urbana, Illinois CONTENTS Ne NIRE ENE WETINE DSRS fe PSC 20 Fes) os sxe e a Ola o's fs¥s0 adobe Ree a ] aE LSU EMERPEVOLOGICAT “UN VESTIGATIONS. .........< ¢ads «6+ 9 00s cae eee bee ee ee ee 18 OLE S UST LIRR EGE) ON OMe ie ee rr arin Geils eee ite: MORN Eee. os 21 ape andatan Salamanders): 2 > s «isd. 0 oi. bo holds eae ee es ee Baga OC rypstOD GAME HIdAG! cic... s)4.e cl ax! ae.cnc, eps hialaad alicia soare eR es eae 25 PB An Oy COU SEOMIAIGAE@ 88 oo Sts). icy dane cv Co ae ee ee eee 27 Area RaT Py PATNA ERA foie ced 5S alvgerte aoa 8 Otago ao este aes a ee 39 Pe taaa yp eg ORAL AE S525 nd asc s+ a oo. «= Sere hae SRE See eee ee 4] Eran Capt AABN LURRPTTETEN AG os 25S. 5 oc a.x 0:8 Seok ae a ope Dc epee 61 PC aTaaE Oat ee GOREN AEE oe ers 2! sieve, fo nv=,0°% ord a, avert os Se OIE el A eer TOO 61 PAE LMMAAGM AER 5c5iasd coea > 2 «ond bs oe eae aie te oe ee 63 Simemaancntiajcenoassand. Loads)... 6. «1s ca-nehe « Ae are cele ae eee ae 66 Berra ise NACA AE. = is Shediac. 2 4 can 5.2 ooo aes a oe tees ee es 69 IAP Aa Ta ERPS LEAP LEE aro 8ic 5 co as = nh ihiiy Diam Safina Ba Sut Siete locate oe nN IC is 71 LDV Era eG: Vo" oS ae ar wear e ean R et e ETRS n, Re Om er 77 HE aaa ETA RETA eI val re oe aos > they ose Ace a iol PCOS, Rete oe ee 93 PBPPenL liye WB LESUAET AC aE 24.9) st a eowlage whale atk oo ala aa) Oo ae ne eg ee ee ee ee 111 “litte Ler lie Seater 2 Os, a nn i a i etie ene et nari Ane ae 113 et Wiest d ites @eeEleS)):5 2 ia/..- a, a lssds'otm Drocoierciay Sieieh aqui = Uo ae eel cette ae 114 apiastue e ne Inct ae ei cinie a.). CaS wn am on ee eee 117 BP amailiualernOstemitd aes. 2 ci. 0oe es ptads cleo ae ee ae Or Toe CR ee 122 IP arava Ce Sti. 3s eset "= aloe, oe «als cater tebe ow Like occ ee ee SL 129 Beemer i EOnMeWiae ctesSisfet sk bss 5 x AAO ea a ee te a 154 BUR cpt as SOMMER aR aE Ags eee ae ech, SAS, «nw ig Seas > dt oh meee RR aE, ee ene 159 SCL LS cols Th ote eh ee ee a Sa 7 Pye ara et ame Pog 2a 159 Ie eann yah Recen AAA GL REE Se ag A gh ao. dysteoni'e oe. abo DRIES ete eae oR rete 160 eA y a AMINO TAG Sey 25 ost. ace tse aa eat er staccato ae a ee 163 SPOUT STE Vos eg A ABER RC Re ee SO IRE eC 165 TaN SCLC Pars a> ap nie « S vin etghe. « ais: Shay eee Sear are aeRS nt eee ORE 166 PCRS ee SEP CIEE Stes iso eo oot dna fee Vw etal a ee ana Bie ne Eales s 172 errata Ole Gidaer. 2) = 3s. 5 ates aaa, ao ciate agate dee Reger a uote ciate oye atts 177 ern EE AIG 4Oe cs. cs San Be, bese the Sigs ais, EVES SON ae aR a AO pal 263 SOE RU METRICS re Te ea ers sii tg ial ofan « nn aueias 2 BR ARS dead aS OR Ree Be 274 INSERT SKA re PESO ee eke k 2 le oe ey eee i, ee baene aaa 287 Robert Kennicott 1835—1866 Harrison Garman 1858—1944 y Karl P. Schmidt 1890—1957 Alvin R. Cahn 1892— ® Clifford H. Pope 1899 Fred R. Cagle 1915— Important contributors to the knowledge of the Illinois herpetofauna. The Amphibians and Reptiles of Illinois THE AMPHIBIANS AND REPTILES comprise -wo classes of vertebrate animals. The class Amphibia includes three present-day or- Jers, the Caudata (salamanders), Salientia (frogs and toads), and the Gymnophiona (caecilians). The class Reptilia includes four present-day orders, the ‘estudines (turtles), Squamata (lizards and snakes), Srocodylia (crocodilians), and Rhynchoce- phalia (Sphenodon). In the fauna of Illi- 10is, amphibians are represented by sala- manders, toads, and frogs; reptiles by tur- ‘les, lizards, and snakes. Altogether 109 dif- ferent kinds of these animals have been found in the state. In our natural economy the amphibians and reptiles, because of their predation on insects and destructive rodents, are on the side of man. ‘Their exact role in the so- called balance of nature is at this time poorly known, but their existence is prob- ably of some importance to other organisms in the over-all fauna. To many people am- phibians and reptiles are fascinating and colorful creatures, and the characteristically human desire to investigate the unknown and to accumulate knowledge provides an incentive to study them. The increase in popularity in recent years of these animals is reflected by the number of people who now have pet turtles, lizards, and snakes. Four of our Illinois snakes are poisonous. Although these snakes are uncommon in most parts of the state, a few persons are bitten by them, and many persons worry needlessly because harmless species are mis- taken for poisonous species. It is advisable for everyone who spends much time out-of- doors to learn to distinguish the poisonous species; this can be done readily with the information in this bulletin. A detailed study of the present-day Illi- nois amphibians and reptiles is bringing to light important data that help the scientist to look back into the past history of the earth and its life. Illinois has contributed especially significant data to biogeography, particularly in helping to disclose the move- ments of animals in and around Illinois dur- = L PHILEPE W.-S Mit ing the advance and retreat of the glaciers of the Pleistocene. The objectives of this report on the am- phibians and reptiles of Illinois are three- fold. The first is to provide a critical re- view of the species and subspecies known to inhabit Illinois. The second is to present de- tailed distributional information for these animals in the hope that the data may con- tribute to the knowledge of the ecology and biogeography of Illinois. The third is to call attention to variation trends that I have discerned within Illinois and that will en- able future investigators to utilize character analyses for populations occurring in lim- ited parts of the state. ACKNOWLEDGMENTS The co-operation of several institutions and a great many persons has materially in- creased our knowledge of the herpetofauna of Illinois. The institutional and private collections that have made their holdings available to me are as follows: Chicago Academy of Sciences, Chicago, Illinois (CAS); Carthage College, Carthage, IIli- nois (CC); Chicago Natural History Mu- seum, Chicago, Illinois (CNHM); collec- tion of Charles W. Myers, St. Louis, Mis- sourt (CM); Cornell University, Ithaca, New York (CU); Eastern Illinois Univer- sity, Charleston, Illinois (EIU) ; collection of Fred A. Shannon, Wickenburg, Arizona (FAS); field zoology collection accumu- lated at the University of Illinois by the late H. J. Van Cleave, Urbana, Illinois (HJVC); Illinois Natural History Survey, Urbana, Illinois (INHS); Illinois State Museum, Springfield, Illinois (ISM); col- lection of James C. List, Paducah, Ken- tucky (JCL); Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts (MCZ); Nebraska State Museum, Lincoln, Nebraska (NSM) ; Prin- cipia College, Elsah, Illinois (PC) ; collec- tion of Richard A. Edgren, Chicago, Illinois (RAE); collection of Robert C. Schroder, Rock Island, Illinois (RCS); Rockford 1] bo Museum of Natural History, Rockford, Illinois (RMNH); collection of Sherman A. Minton, Indianapolis, Indiana (SAM) ; Southern Illinois University, Carbondale, Illinois (SIU); University of Illinois Mu- seum of Natural History, Urbana, Illinois (UIMNH); University of Michigan Mu- seum of Zoology, Ann Arbor, Michigan (UMMZ) ; University of Rochester, Roch- ester, New York (UR); United States Na- tional Museum, Washington, D. C. (USNM). I am indebted to the following persons for the privilege of examining material de- posited in the above mentioned collections: Esther Bennett, Fred R. Cagle, Doris M. Cochran, D. Dwight Davis, William E. Duellman, Richard A. Edgren, William E. Fahy, Howard K. Gloyd, Norman Hart- weg, Donald F. Hoffmeister, Robert F. Inger, Remington Kellogg, Alice Kibbe, James N. Layne, James C. List, Hymen Marx, Sherman A. Minton, Charles W. Myers, R. Earl Olson, Paul W. Parmalee, James A. Peters, Clifford H. Pope, Walter M. Scruggs, the late Karl P. Schmidt, C. Bertrand Schultz, Fred A. Shannon, Ho- bart M. Smith, Charles F. Walker, John F. Wanamaker, and T. Gilbert Wright. Sizable personal collections of specimens have been donated to the Illinois Natural History Survey by Jack Daugherty, Ed Keiser, Jr., Dave A. Langebartel, R. Earl Olson, Robert C. Schroder, Warren P. Sights, Jerry Staedeli, and Harlan D. Wal- ley. Specimens contributed from time to time by Richard W. Abbuhl, W. Leslie Burger, Donald J. Daleske, M. Max Hens- ley, James E. Huheey, Harold R. Hunger- ford, Allan H. Keith, R. Weldon Larimore, Ross J. Miller, Thomas E. Moore, William B. Robertson, Milton W. Sanderson, Robert Shoop, Lewis J. Stannard, and Kenneth L. Williams have been invaluable in filling in distributional gaps. Smaller lots of speci- mens and information have been contrib- uted by so many persons that they cannot be listed individually here. The assistance of each is sincerely appreciated. I wish to thank Howard K. Gloyd, who actually initiated this study, for relinquish- ing the results of his preliminary investiga- tions. I have profited by discussing with Hobart M. Smith, Herbert H. Ross, Sher- man A. Minton, and Roger Conant many of the problems encountered. I have been Ittrinois NaturAL History SurveEY BULLETIN Vol. 28, Art. 1 advised by several investigators on problems relating to their particular specialties, and acknowledgment for their assistance ap- pears in appropriate places throughout the text. For countless profitable consultations on editorial problems that arose during the writing of the manuscript and for reading proof, I owe a special gratitude to my asso- ciate, Mrs. Leonora K. Gloyd. For her accurate typing of the manuscript and for her vigilance in detecting inconsistencies, I am grateful to Mrs. Thelma H. Over- street. For illustrations, I am indebted to several persons, most of them formerly or presently on the staff of the Natural History Survey. The key illustrations were done by Joseph I. Leveque and Mrs. Alice Ann Prickett; the drafting by Miss Marguerite M. Ver- ley. Most of the photographs were taken by William E. Clark; smaller numbers were taken by Charles L. Scott, Robert E. Hesselschwerdt, and Harry Fisher. The photos by Mrs. Isabelle Hunt Conant (figs. 16, 89, 115, 149, 190, 210, and 229) are from the photographic collection of Roger and Isabelle Hunt Conant. The photograph of Robert Kennicott in the frontispiece is reproduced through the courtesy of the Chi- cago Academy of Sciences, that of Harrison Garman through the courtesy of Dr. Lee R. Townsend of Lexington, Kentucky, and that of Karl P. Schmidt through courtesy of the Chicago Natural History Museum. For editing the manuscript and for read- ing of the proof, I am grateful to James S. Ayars, Mrs. Diana R. Braverman, Mrs. Nira J. Nelson, and Mrs. Blanche P. Young. I am indebted to my former major pro- fessor, Hobart M. Smith, to my immediate superior, Herbert H. Ross, and to my wife, Dorothy M. Smith, for continuous help throughout the course of this study. PREVIOUS HERPETOLOGICAL INVESTIGATIONS Three reports on the amphibians and rep- tiles of Illinois have appeared. One of these is a briefly annotated check list, one a key only, and one an excellent account, which is, however, more than 60 years old. Four pa- pers dealing with limited groups of the her- petofauna and approximately half a dozen papers treating the species of limited re- November, 1961 gions within Illinois have been published. The great majority of the references to IIli- nois in the literature are incidental, either citing specimens collected at localities in Illinois or merely stating that Illinois is within the range of the species. The earliest specific reference to an am- phibian or reptile in Illinois appears to be an observation by Thomas Say (1823) in the account of Long’s expedition to the Rockies, just 5 years after Illinois became a state. Say records in his narrative that he observed a female of the then recently de- scribed Graptemys geographica laying eggs on the bank of the Ohio River near Shaw- neetown. Fifteen years later Holbrook (1838) described Emydoidea blandingi from the Fox River of northern Illinois. Geb- hard (1854) recorded the first amphibian for the state by citing a specimen of Hemi- dactylum [sic] from Illinois. Kennicott (1855) prepared the first regional list with his catalog of Cook County quadrupeds. His list records 12 amphibians and 21 rep- tiles still recognized as part of the Cook County fauna. Later Kennicott (1856) de- scribed Natrix kirtlandi from West North- field, and (1859) Virginia valeriae elegans from “southern IIlinois,” and Ophibolus ev- ansit from “central Illinois.” During the next 25 years such authors as Cope, Cooper, Yar- row, Jordan, and Kennicott published pa- pers containing incidental references to the herpetofauna of Illinois. Davis & Rice (1883a) published the first state list; their check list correctly recorded 29 species of amphibians and 54 reptiles, as well as a number of other species whose oc- currence is now known to be quite impossi- ble in Illinois. In the same decade Schneck (1880-1886), a physician and naturalist in Mount Carmel, was active in the Wabash River valley, and his several short notes in the American Naturalist recorded a num- ber of reptiles in southeastern Illinois. Cope (1888) described Lampropeltis triangulum syspila from Richland County and (1889) Hyla phaeocrypta from Mount Carmel. Harrison Garman (1889, 1890) recorded the animals occurring in the Mississippi River bottoms near Quincy and reported several species for the first time from the state. Hay (1881-1892), studying the her- petology of Indiana, contributed to the knowledge of the Illinois herpetofauna by citing Illinois localities for several species. Sm1ITH: AMPHIBIANS AND REPTILES OF ILLINOIS 3 Cope (1892) described Thamnophis sirtalis semifasciata from’ Des Plaines in northeast- ern Illinois. The synopsis by Harrison Garman (1892), until now the only comprehensive report on the Illinois amphibians and rep- tiles, credited correctly 31 species of am- phibians and 58 reptiles to Illinois, but un- fortunately perpetuated most of the errors of Davis & Rice. Hurter (1893-1911) added several species to the known fauna ot southwestern Illinois and, in his Herpetol- ogy of Missouri, described Chrysemys tre- leasei from Madison, St. Clair, and Monroe counties, Illinois. In the early part of the present century, Robert Ridgway was responsible for a great quantity of Illinois material which found its way into the United States National Mu- seum. Ridgway was also responsible for a number of erroneous records, presumably based on his recollections of species proba- bly misidentified in the field. Shelford (1913) cited a number of species for north- eastern Illinois in his Animal Communities of Temperate America. Gaige (1914) re- corded 16 species of amphibians and reptiles for Richland County, and Hankinson (1910- 1917) reported the common species of Coles County. Weed (1922, 1923) studied the amphibians and reptiles of the Meredosia area, and Blanchard (1924) reported sev- eral new records for Monroe and Randolph counties. Van Cleave (1928) prepared tab- ular keys for the identification of the snakes of Illinois. About 1930 K. P. Schmidt stimulated an interest in the amphibians and reptiles of the Chicago region, and his popular ac- counts of the amphibians (1929, 1930) were followed by a number of papers by Walter L. Necker and others. Schmidt & Necker (1935) published a useful report on the Chicago area species and cited specific locali- ties for all the known amphibians and rep- tiles listed. W. F. Stanley, working for the Illinois Natural History Survey, accumu- lated a considerable number of Illinois snakes through co-operation of the Civilian Conservation Corps. Burt (1928-1931) cited Illinois specimens in several brief pa- pers on the herpetofauna of the Midwest. Goodnight (1937) prepared a key to the salamanders of Illinois, and Cahn (1937) published his excellent monograph of the turtles of the state. + ILttrnois NATURAL History SurveY BULLETIN About 1940 Cagle began publishing the results of his studies on the fauna of south- ern Illinois and in 1941 he published an illustrated key to the amphibians and rep- tiles known for the entire state. This much- needed key was the third paper to treat all amphibian and reptile groups of Illinois. Thirty species of amphibians and 67 of rep- tiles were recorded as occurring in the state. Owens (1941) reported the common spe- cies in Macoupin County, and Lueth (1941) wrote a popular manual of the snakes of Illinois. Peters (1942) listed the species known to occur in Cumberland County, and Cagle (1942a) published a detailed account of the herpetofauna of Union and Jackson counties. Pope (19446) summarized the distributional information of the several papers on the amphibians and reptiles of the Chicago area in his extremely useful hand- book on the species occurring in northeast- ern Illinois. Langebartel (1947) reported the snakes known to occur in Hancock County and added Carphophis amoenus vermis to the known fauna of the state. P. W. Smith (1947) analyzed the herpetofauna of east-central Illinois and recorded 50 spe- cies and subspecies for that part of the state. Edgren & Stille (1948) published several papers on the species inhabiting the Chicago region and they added numerous distribu- tional records for northeastern Illinois. Minton & Minton (1948) cited a number of specimens from southern Illinois, and Grimmer & Langebartel (1948) reported Eurycea longicauda melanopleura as a state record for Illinois. P. W. Smith (1948) added Plethodon dorsalis and Gastrophryne carolinensis to the known amphibian fauna and confirmed the suspected occurrence of Desmognathus fuscus and Scaphiopus hol- brooki in Illinois. Smith & Burger (1950) reported the first Illinois specimens of Masticophis flagellum, Elaphe guttata, and Tantilla gracilis, and P. W. Smith (1951) described and named Pseudacris streckeri illinoensis and Kino- sternon flavescens spoonert from western Illinois sand prairies. Bennett (1953) added Cemophora doliata to the known snake fauna. P. W. Smith (1953-1957) summar- ized the known distribution in Illinois of Tropidoclonion lineatum and Hyla avivoca; resurrected the name semifasciata for the population of garter snakes occurring in northeastern Illinois; called attention to a Vol. 28, Art. 1 south-north clinal reduction in number of body blotches in snakes, a reduction that presumably is a manifestation of Gloger’s Rule; and offered a reconstruction of the post-Wisconsin biogeography of Illinois and neighboring states. Smith & Minton (1957) summarized distributional data for Indiana and Illinois and discussed postglacial dis- persal patterns of amphibians and reptiles. ILLINOIS AS A HERPETOFAUNAL REGION The natural areas of Illinois have had a great amount of human alteration within historic times. Many natural habitats have been transformed into cities or cornfields, others greatly reduced in extent, and still others variously modified from their orig- inal condition. In a sense, all of the habitats are relictual, separated from each other by expanses of cultivated fields. The state could be described as a great corn desert containing remnants of many habitat types. Although herpetological collecting is rela- tively poor in most parts of the state, IIli- nois has an unusually large number of re- corded species and subspecies. The _ rich- ness of its fauna, from the standpoint of numbers of species, is due to its great length from north to south, its ecologically inter- mediate position, its biogeographical history, and its variety of habitat types. Physical Features Illinois, fig. 1, has a maximum length of approximately 385 miles from north to south and a maximum width of 215 miles from east to west. The state, which contains 56,400 square miles, is moderately well drained by rivers flowing into the Mississippi on the west, the Ohio on the south, and the Wa- bash on the east. The greater part of the state is a flat or rolling plain. The eleva- tion, which averages about 600 feet for the entire state, decreases from north to south. The lowest part of Illinois is in Alexander County, at the southern tip, approximately 300 feet above sea level. The Shawnee Hills, which extend across the state near the southern tip, the unglaciated area in extreme northwestern Illinois, and a nar- row belt of rock bluff and dissected hills along the Mississippi River have moderate relief; the first two areas have elevations slightly over 1,000 feet. ‘ovember, 1961 SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 5 ROCK RIVER GREEN RIVER FOX RIVER DES PLAINES RIVER KANKAKEE RIVER VERMILION RIVER SANGAMON RIVER . ILLINOIS RIVER . MISSISSIPP] RIVER KASKASKIA RIVER EMBARRASS RIVER . WILLIAMSON WABASH RIVER LITTLE WABASH RIVER . CACHE RIVER BIG MUDDY RIVER wee . OHIO RIVER . SALINE RIVER OvOZSrAL-LOmmMgOF>y JO DAVIESS STEPHENSON WINNEBAGO vor CARROLL cl DE KALB Pim, ' ots Pies KENDALL a HENRY [BUREAU ROCK ISLAND ped MERCER f och PEORIA am IROQUOIS, WOODFORD = JASPER / K sees EFFINGHAM ' CLAY CRAWFORD 4 JEFFERSON q 3 4 = ml a WASHINGTON NDOLPH | PERRY HAMILTON FRANKLIN SALINE ie? u Fig. 1.—Map of Illinois showing counties and major rivers. Ittrnois NATURAL History SurRvVEY BULLETIN Vol. 28, Art. 1 GREAT LAKE >" TILL PLAINS SECTION WISCONSIN (| re g SECTION | Rock ! River | H CENTRAL TOM. ee i LOWLAND y Hill | Country PROVINCE ae ieidthie. 2. PLAINS THe DISSECTED PLATEAUS LOWLAND PROVINCE PROVINCE —'—\ INTERIOR LOW PLATEAUS "ER \)__ PROVINCE COASTAL PLAIN | PROVINCE ILLINOIS STATE GEOLOGICAL SURVEY Fig. 2.—Physiographic divisions of Illinois. From Leighton, Ekblaw, & Horberg (1948 November, 1961 The present topography reflects the Pleis- ocene history of the area. Although four tages of glacial advance, separated by inter- lacial periods of milder climate, are known o have occurred, the Illinoian lobe (over Freeport Mean Jan. temp. Mean July temp. Mean annual temp. Mean inches snowfall Frostfree days Annual precipitation Mean Jan. temp. 28.3 Mean July temp. 80.2 Mean annual temp. S15 ppl Mean inches snowfall eo Frostfree days 180-190 Annual precipitation 36-38 i AS SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 7 100,000 years ago) and the Wisconsin lobe (about 20,000 years ago) are largely re- sponsible for the physiography of Illinois. Much of the northern half of the state is covered with thick deposits of relatively re- Chicago Mean Jan. temp. Mean July temp. 73.0 Mean annual temp. 49.4 Mean inches snowfall acd Frostfree days Annual precipitation Mean Jan. temp. Mean July temp. 75.4 Mean annual temp. oes Mean inches snowfall 20.6 Frostfree days Annual precipitation 36.1 79.5 58.4 Mean Jan. temp. Mean July temp. Mean annual temp. Mean inches snowfall 9.9 Frostfree days -200 Annual precipitation 42-44 Fig. 3.—Temperature and precipitation data for five Illinois cities. Data from Page (1949). 8 Ittinors NaTuRAL History SurvEY BULLETIN cent Wisconsin till. Superimposed on this in gradually increasing depths to the west are deposits of fertile loess. The flat or rolling plains are marked by series of low concentrically arranged recessional mo- raines, the southernmost of which is the Shelbyville terminal moraine. The glaciated area south of the Shelby- ville moraine has deposits of older, less fer- tile Illinoian till, and moraines are no longer evident. This region has slightly more re- lief than the area north of the Shelbyville moraine, since the processes of erosion have had a longer time to cut valleys. Rock outcrops are prominent features in the landscape in the Shawnee Hills, in the northwestern unglaciated area, and along the large rivers. Rock strata appear above the glacial till in small areas throughout the state, particularly in extreme eastern and western Illinois. The physiographic divisions of Illinois have been described by Leighton ef al. (1948). These divisions are shown in fig. 2. Climatic Features Illinois has a continental climate. The isotherms are in general from east to west and indicate an increase in temperature from north to south. The difference in av- erage temperatures between northern and southern Illinois is much less marked in summer than in winter. The isohyets are somewhat less regular than the isotherms; in general, the annual precipitation increases from north to south. Union County re- ceives a greater amount of rainfall than any other county. The influence of latitude on temperature and the geographic variation in precipita- tion are illustrated by statistics taken over a period of several years at scattered IIli- nois localities, fig. 3. Biotic Provinces According to the Merriam (1894) classi- fication, Illinois contains three life zones. Extreme northern Illinois is regarded as Transition, extreme southern Illinois as Austroriparian, and the area in between as Carolinian. According to the Shantz & Zon (1924) classification, Illinois includes four vegetation types. Extreme northeastern IIli- nois is classed as Marsh Grass, most of northern and central Illinois as Tall Grass Prairie, southern Illinois, except for the Vol. 28, Art. | lowermost tip, as Oak-Hickory Forest, and extreme southern Illinois as River Bottom Forest (cypress-tupelo-red gum). According to Dice (1943), the state has three biotic provinces. The northern half is regarded as Illinoian; the southern half, except for the southern tip, as Carolinian; and extreme southern Illinois as Austroriparian. Ken- deigh (1951) indicates the presence of two biomes in Illinois. The northern half is pre- dominantly Grassland Biome, the southern half Temperate Deciduous Forest Biome. The forest is subdivided into three asso- ciations, the largest of which is an ecotone between oak-hickory forest and humid prai- rie. The animal communities are regarded as a Deciduous Forest Biociation, a Decid- uous Forest-Edge Biocies, and a Prairie Biociation. All of these classifications are based on the vegetation or biota of the entire conti- nent, and the boundaries are necessarily in- exact in any minute geographical area. It is noteworthy that all of them indicate that the southern tip of this state is ecologically distinct, and most of them indicate in cen- tral Illinois an ecological break that roughly coincides with the southern limit of Wiscon- sin glaciation. A detailed classification of zones in IIli- nois is expressed by Vestal (1931), who based his divisions upon forest types. In many parts of the state, the distribution of the herpetofauna parallels remarkably the distribution of these types. Vestal’s map of Illinois has the following eight divisions: Grand Prairie, Western Division, Jo Da- viess Hills, Mississippi Border, Southern Division, Wabash Border, Ozark Hills, and Tertiary Division, as shown in fig. 4. Herpetofaunal Divisions Although the herpetofaunal distribution tends to coincide with the vegetational divi- sions of Vestal (1931), certain differences exist that should be recognized. The dis- tinctive herpetofaunal divisions are outlined below and shown in fig. 5. I. Prairie or former prairie A. Sand areas B. Grand Prairie (broad sense) C. Outlier prairies Il. Forest A. Northeastern Illinois Mesic For- est B. Western Division November, 1961 SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 9 Et | | I ' i} ( ------——-—---4 jj PRAIRIE CI NG ee : FOREST S Zipp ¥ oe 7] GRAND PRAIRIE Ay DIVISION \ ie ZZ a ee SOUTHERN \ foe BA | DIVISION \\ . == = AAI OZARK HILLS \=== MA = ++] \) TERTIARY DIVISION JO DAVIESS \ HILLS WY MISSISSIPPI BORDER WABASH BORDER A UWI AWS" > Fig. 4—Vegetation map of Illinois, based on original cover. From Vestal (1931). Forest occupies a relatively small per cent of Illinois at present. 10 ILttnois NaTurAL History SurRVEY BULLETIN Vol. 28, Art. 1 Zz . per. \ i} tes | + -4 vi r Teen [] Pate Northeastern Mesic age Woodlands Division EE | Woodlands of the i Grand Prairie Division GW Western Division Gi Woodlands Southern Division Woodlands Shawnee Hills Division WY hen eotars Lower Mississippi Border Division LZ Oa Cm a Upper Mississippi Border Division Wabash Border Division Sand Areas Fig. 5—Herpetofaunal divisions of Illinois. The similarity of herpetofaunal, vegetationa and physiographic divisions is notable. Coincidence of boundaries is most pronounced at th southern limits of Pleistocene glaciation and the northern border of the Coastal Plain. November, 1961 Upper Mississippi Border Lower Mississippi Border Southern Division Wabash Border Shawnee Hills Austroriparian Ninety-four species of amphibians and eptiles occur in Illinois; 25 are state-wide n distribution and 69 occupy limited parts yf the state. The edges of ranges of these 9 have been plotted on one map, fig. 6. It s evident from this map that the ranges of he various species are not uniformly shin- ‘led over the state but that the range edges yf many tend to coincide. Some areas are elatively uniform ecologically and have ew species reaching the edges of their ‘anges therein. Fig. 6 demonstrates the va- idity of fig. 5. The Sand Areas.—The areas of sand yrairie, which are relatively small, are mam oO \\ “Qiks i Fig. 6.—Limits of distribution of the am- phibians and reptiles of Illinois. Each line represents the edge of range of a species. In some areas, lines coincide. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS ili! chiefly in central and northern Illinois. The largest area extends along the east side of the Illinois River from Woodford County south to northern Scott County. Smaller sand areas occur in Jo Daviess, Carroll, Rock Island, Whiteside, Mercer, and Hen- derson counties, along the east side of the Mississippi River; in Ogle and Lee counties; in Winnebago County; in Kankakee and Iro- quois counties. Small areas of sandy loam occur in Lawrence, La Salle, and Lake coun- ties. A typical sand prairie habitat is shown in figs. # The most abundant reptiles of the sand areas are Cnemidophorus sexlineatus, Pituo- phis melanoleucus sayi, Coluber constrictor flaviventris, Heterodon platyrhinos, Hetero- don nasicus, Terrapene ornata, and Tri- onyx muticus. ‘The distinctive species of amphibians and reptiles are Pseudacris streckeri illinoensis, Kinosternon flavescens spooneri, and some of the reptiles mentioned as abundant are also characteristic. A de- pauperate salamander fauna and the local predominance of Bufo woodhousei fowleri over Bufo americanus americanus are also characteristic of this division. The Grand Prairie.—This division as here defined comprises all original prairie, except the sand areas, north of the southern limit of Wisconsin glaciation. It includes accordingly the Grand Prairie (in the strict sense), the Mendota Prairie, and most of the prairies included in Vestal’s Western Division. Much of this area has fertile soil, consisting of Wisconsin glacial till and loess, and is now extensively cultivated. It has been characterized by various authors as muck prairie, black-soil prairie, and heavy- soil prairie. The eastern part of the area was formerly dotted with marshes and ponds, most of which have been drained. The most abundant species of amphib- ians and reptiles are Bufo americanus amer- icanus, Thamnophis radix, Elaphe vulpina, Pituophis melanoleucus sayi; probably Sis- trurus catenatus and Emydoidea blandingi were once abundant. The distinctive spe- cies are Natrix kirtlandi, Tropidoclonion lineatum, Opheodrys vernalis, as well as some of the above species indicated as abun- dant. Although none of these is entirely re- stricted to the Grand Prairie, each reaches its greatest abundance in the region. The Outlier Prairies——These fingers of prairie, which interdigitate with forest in the 12 Ittinois NaruraAt History SurvEY BULLETIN Vol. 28, Art. 1 Fig. 7—A typical sand prairie habitat near Thomson, Whiteside County, Illinois. southern half of Illinois, were included by Vestal in the Southern Division. The north- ern edges of this division are not sharply delimited from the Grand Prairie, and the Springfield District of Vestal is, in fact, eco- tonal in herpetofaunal composition. ‘The soil is rather poor, consisting of clay loam with hardpan a foot or two below the sur- face. The abundant species are Ambystoma texanum, Bufo woodhousei fowleri, Coluber constrictor, Lampropeltis calligaster, and Heterodon platyrhinos. The distinctive spe- cies are Rana areolata and Terrapene or- nata. A few relict colonies of Opheodrys vernalis, Thamnophis radix, Sistrurus cate- natus, and Natrix grahami link this divi- sion with the Grand Prairie. The erratic occurrence of some of these scattered colo- nies is difficult to explain. It seems unlikely that cultivation is solely responsible. Northeastern Illinois Mesic Forest.— The forested moraines and bogs near Lake Michigan contain a relatively rich fauna and are distinctive chiefly because of the occurrence of northern and eastern ele- ments. The abundant species are Ambys- toma maculatum, Rana sylvatica, Lampro- peltis triangulum triangulum, Storeria oc- cipitomaculata, and Natrix septemvittata. The distinctive species are Ambystoma lat- erale, Hemidactylium scutatum, Clemmys guttata, and Thamnophis sirtalis semifasci- ata. The Western Division—The small patches of woodland and gallery forest along rivers and creeks of this division are rather remarkable for their impoverished fauna. Although apparently suitable habitat for many forest species is available, most of the species known in adjacent divisions have not been found in these forested areas. Acris crepitans, Pseudacris triseriata tri- seriata, Rana pipiens pipiens, Rana clami- tans, Thamnophis sirtalis, and Lampropeltis triangulum are moderately common; all are more abundant in other parts of Illinois. The Upper Mississippi Border.—This division, which includes the forested bluffs of the Mississippi River and the Jo Daviess County driftless area, is much richer in number of species than the Western Divi- sion. The extensive rock habitat and the continuity of forest along the Mississippi, which serves as an avenue for the north- ward dispersal of southern animals, prob- ably accounts for the large number of spe- cies in this area. The common species are Natrix sipedon, Diadophis punctatus, Elaphe obsoleta, Thamnophis sirtalis, and Rana clamitans. The distinctive species are Eurycea longi- cauda melanopleura, Carphophis amoenus vermis, Diadophis punctatus arnyi, and Rana palustris. The Lower Mississippi Border.—The bluffs and dissected upland along the Mis- sissippi River south of St. Louis have a spe- November, 1961 cies composition and an order of relative abundance similar to that of the Upper Mississippi Border. This division has more affinities with the Shawnee Hills, however, and has, in addition, several western and southern elements not found elsewhere in the state. The distinctive species are T'an- tilla gracilis, Masticophis flagellum, Elaphe guttata emoryi, and Gastrophryne carolin- ensis. The Shawnee Hils.—This division is characterized by forested, dissected upland with sheer bluffs and rock outcrops. The streams, usually fast and clear, have rocky bottoms. The area is rich in numbers of species and individuals. The abundant spe- cies are Ambystoma opacum, Plethodon glutinosus, Eurycea longicauda, Eurycea lu- cifuga, Hyla crucifer, Hyla versicolor, Sce- loporus undulatus, Scincella laterale, Eu- meces spp., Agkistrodon contortrix, Elaphe obsoleta, Coluber constrictor, Thamnophis sauritus, Virginia valeriae, and Terrapene carolina. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS ] ios) The Southern Division.—The forest of this part of Illinois is largely restricted to river bottoms and land generally unsuited for farming. The habitat is similar to that in the Shawnee Hills but has less relief and few rock outcrops and rocky streams. The unintentional creation of parklike savannas by removal of forest provides ideal habitat for forest-edge species. “The thickets, brambles, and grass (Andropogon) glades characteristic of this habitat are in- habited by Bufo woodhousei fowleri, Am- bystoma texanum, Heterodon platyrhinos, Coluber constrictor, Opheodrys aestivus, Storeria dekayi, and Natrix sipedon pleu- ralis. ‘The interior of the woodlands contain Eumeces spp., Elaphe obsoleta, Lampropeltis triangulum syspila, and Hyla versicolor. The Wabash Border.—The area along the Wabash River in southeastern Illinois is similar to the Southern Division, differ- ing primarily in the higher percentage of forested land and the mesic condition of this forest. Characteristic species are Hyla cru- Fig. 8.—A typical austroriparian habitat at Horseshoe Lake, Alexander County, Illinois. 14 Ittinois Narurav History SurvEY BULLETIN cifer, Pseudacris triseriata feriarum X tri- seriata, Eumeces fasciatus, and Terrapene carolina. Additional characteristic species are Rana sylvatica, Natrix septemvittata, Natrix erythrogaster neglecta, Eurycea bis- lineata, Plethodon cinereus, and Elaphe ob- soleta obsoleta X spiloides. The Austroriparian Division.—This area is the Tertiary Division of Vestal (1931), the River-Bottom Forest of Shantz & Zon (1924), and the Austroriparian of earlier authors. It includes the floodplains, fig. 8, of the Mississippi and Ohio rivers in Alexander, Pulaski, Massac, Pope, western Union, and southwestern Jackson counties. A number of species characteristic of the Gulf Coast extend up the Mississippi River valley into this division. Some of these spe- cies are Ambystoma talpoideum, Hyla cin- erea, Hyla avivoca, Scaphiopus holbrooki, Farancia abacura, Natrix cyclopion, Natrix sipedon confluens, Cemophora doliata, Agkis- trodon piscivorus, Pseudemys floridana, and Macroclemys temminchki. PRESENTATION OF DATA The bulk of the data for this report was accumulated during the years 1947-1953. Field work was conducted in almost all parts of the state and was particularly in- tensive in the peripheral areas. Records for the approximately 8,000 specimens in the Illinois Natural History Survey collection were supplemented by Illinois records from the major museums of this country, several state institutions, and a few private collec- tions. Complete synonymies for all Illinois spe- cies and subspecies have been compiled, but, because of their bulkiness, they have been replaced by skeleton synonymies; the syn- onymy for each species or subspecies con- sists of a chronological outline of all names and name combinations that have been ap- plied to the taxon in the Illinois literature. Only the initial usage of a name or name combination is cited. The remaining biblio- graphic references and lists of published rec- ords from the time of the original descrip- tion through the appearance of the sixth edition of the official check list (Schmidt 1953) are on file at the Illinois Natural His- tory Survey offices, where they are available to anyone interested in the historical as- pects of the Illinois herpetofauna. Vol. 28, Art. 1 The initial citation in every case is to the original description, whether or not Illinois is mentioned; the specific or subspecific name is followed by the name of the describer (with no comma separating them), the year the description was published, the pagina- tion of the description, and, in parentheses, the type locality. A citation other than the original description refers to the first usage of the name in literature pertaining to Llli- nois; a comma follows the specific or sub- specific name, and the reference is abbrevi- ated to author, year, and pagination. The complete reference for each citation is given in the “Literature Cited” section of this paper. If a citation refers to two different en- tities as now understood, the name appears in the synonymies of both forms involved and is followed by “part” in parentheses. When the citation refers to specimens or populations of intergrades between two sub- species, the name ordinarily is included in the synonymies of both forms and is fol- lowed by “I” in parentheses. The various names and name combinations have been carefully evaluated, and most of them have been definitely allocated by judicious use of our present knowledge of distribution. In a few cases some doubt about assignment of the name remains; in each of these cases the name is prefaced by a question mark. In several instances questionable records in the literature have been clarified by exam- ination of the museum specimens on which the records were based. The diagnosis for each species is brief and includes only those characters or com- binations of characters serving to distinguish an animal from related or similar animals. In most instances it is designed merely to supplement the keys. Exceptions are made, however, for those populations which depart in structure, pattern, or color from pub- lished descriptions of the species or sub- species. The section on variation in each species or subspecies includes a discussion of sexual dimorphism, ontogenetic variation, and geo- graphic variation within Illinois. In an ani- mal that occurs in a limited part of the state, individual variation is summarized. It has been assumed, in accordance with present species concepts, that each individual population probably differs to some extent from all others. Extremes and means of November, 1961 counts and measurements rather than more detailed statistics are given, since they illus- trate general trends and do not require cor- rection factors for the small size of the sam- ples. In most cases, the grouping of the samples analyzed has been selected with an eye to the probable natural limits of freely interbreeding populations. In some cases, however, the grouping has been dictated by the availability of specimens. The habits section for each species or subspecies is intended only to give a brief summary of behavior, feeding habits, and life history information. Although a wealth of published information is available for some of the species, little of this informa- tion is based on Illinois animals. The in- formation in the present paper, for the most part, pertains only to Illinois populations; geographic variation in habits as well as in morphology is to be expected. The section on distribution of each species or subspecies in Illinois contains a general statement of the range of the animal in the state, an indication of its general abundance, apparent correlations of its range and the environmental features, and the extent of the intergrading areas of subspecies. In the interest of saving space, lists of locality rec- ords and specimens examined have been omitted. This information is on file at the Illinois Natural History Survey offices and can be transcribed for persons wishing to know precise localities and catalog numbers of specimens on which a record is based. Published records believed valid but not substantiated by museum specimens are listed alphabetically by counties and spe- cific localities and followed by references to the literature cited. The accompanying maps indicate graph- ically the known Illinois localities for the various species. Localities from which specimens have been examined are indicated by dots; localities for which there are liter- ature records believed valid, but from which I have not seen specimens, are indicated by hollow circles. The presumed range of a species that does not occur throughout IIli- nois is indicated by parallel hatching and is based in part on the distribution of appar- ently suitable habitat. In the case of a spe- cies having two or more subspecies in IIli- nois, the range of each subspecies is indi- cated by a different pattern, and the inter- grading area by an overlap of these patterns SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 15 to form a crosshatch pattern. The map oi the United States that accompanies each Illinois map indicates the total known range of a species and in most cases is from Co- nant (1958). SYSTEMATIC ACCOUNT Amphibians and reptiles comprise two distinct classes of vertebrate animals. The modern species are survivors of those groups of vertebrates that first colonized land. They are intermediate between the bony fishes of an aquatic environment and the birds and mammals of a terrestrial environ- ment. In general, the organ systems of am- phibians reflect the series of profound changes necessary for the transition from water- to air-breathing, from swimming to locomotion on land, and from an environ- ment emphasizing the need for water excre- tion to one requiring water conservation. The organ systems of reptiles reflect the various modifications which made their land colonization more successful than that of the amphibians. In addition to gross differences in organ systems, there are numerous other anatomi- cal features distinguishing the amphibians from the reptiles. These differences are treated in any standard textbook of com- parative anatomy. The most obvious fea- tures distinguishing the amphibians from the reptiles are as follows: Skin without scales or plates; front feet with 4 or fewer toes; toes without claws; eggs with gelatinous coating; typically with an aquatic: larval’ stage... 2. Sieaon3m. > Skin with scales or plates, or both; front feet, if present, with 5 toes; some toes with claws; eggs with a tough membranous or limy covering; no larval stage......-. : Class Reptilia, p. 113 Check List of the Amphibians and Reptiles of Illinois Class Amphibia Subclass Lepospondyli Order Caudata Family Cryptobranchidae Cryptobranchus alleganiensis al- leganiensis (Daudin) Family Ambystomatidae Ambystoma laterale Hallowell Ambystoma maculatum (Shaw) 16 I_turnois NarurAL History Survey BULLETIN Ambystoma opacum (Graven- horst) Ambystoma talpoideum (Hol- brook) Ambystoma texanum (Matthes) Ambystoma tigrinum tigrinum (Green) Family Salamandridae Notophthalmus viridescens lou- isianensis Wolterstorff Family Plethodontidae Eurycea bislineata rivicola Mit- tleman Eurycea longicauda longicauda (Green) Eurycea longicauda melanopleu- ra (Cope) Eurycea lucifuga Rafinesque Hemidactylium scutatum (Schle- gel) Plethodon cinereus cinereus (Green) Plethodon dorsalis Cope Plethodon glutinosus glutinosus (Green) Desmognathus fuscus conanti Rossman Family Proteidae Necturus maculosus (Rafinesque) Family Sirenidae Siren intermedia nettingi Goin Subclass Apsidospondyli Order Salientia Family Pelobatidae Scaphiopus holbrooki (Harlan) Family Bufonidae Bufo americanus americanus Holbrook Bufo americanus charlesmithi Bragg Bufo woodhousei fowleri Hinck- ley Family Hylidae Acris crepitans blanchardi Harper Pseudacris triseriata feriarum (Baird) Pseudacris triseriata triseriata (Wied) Pseudacris streckeri illinoensis Smith Hyla avivoca avivoca Viosca Ayla cinerea (Schneider) Hyla crucifer crucifer Wied maculosus Vol. 28, Art. 1 Hyla versicolor versicolor Le Conte Family Ranidae Rana areolata circulosa Rice & Davis Rana catesbeiana Shaw Rana clamitans melanota (Rafinesque) Rana palustris Le Conte Rana pipiens pipiens Schreber Rana pipiens sphenocephala Cope Rana sylvatica sylvatica Le Conte Rana sylvatica cantabrigensis Baird Family Microhylidae Gastrophryne carolinensis caro- linensis (Holbrook) Class Reptilia Subclass Anapsida Order Testudines Family Chelydridae Chelydra serpentina serpentina (Linnaeus) Macroclemys temmincki (Troost) Family Kinosternidae Sternothaerus odoratus ( Latreille) Kinosternon flavescens spooneri Smith Kinosternon subrubrum subru- brum (Lacépéde) X hippocre- pis Gray Family Testudinidae Clemmys guttata (Schneider) Emydoidea blandingi (Hol- brook) Terrapene carolina carolina (Linnaeus) Terrapene ornata ornata ( Agassiz) Chrysemys picta marginata Agassiz Chrysemys picta belli (Gray) Pseudemys scripta elegans (Wied) Pseudemys floridana hoyi (Agas- siz) X concinna hieroglyphica ( Holbrook) Graptemys geographica (Le Sueur) Graptemys pseudogeographica (Gray) November, 1961 Family Trionychidae Trionyx muticus muticus Le Sueur Trionyx spinifer spinifer Le Sueur Subclass Lepidosauria Order Squamata Suborder Sauria Family Iguanidae Sceloporus undulatus hyacin- thinus (Green) Family Anguidae Ophisaurus attenuatus attenua- tus (Cope) Family Teiidae Cnemidophorus sexlineatus sex- lineatus (Linnaeus) Family Scincidae Scincella laterale (Say) Eumeces fasciatus (Linnaeus) Eumeces laticeps (Schneider) Suborder Serpentes Family Colubridae Carphophis amoenus helenae (Kennicott) Carphophis amoenus vermis (Kennicott) Farancia abacura reinwardti Schlegel Diadophis punctatus arnyi Kennicott Diadophis punctatus edwardsi (Merrem) Diadophis punctatus stictogenys Cope Heterodon nasicus nasicus Baird & Girard Heterodon platyrhinos Latreille Opheodrys aestivus (Linnaeus) Opheodrys vernalis blanchardi Grobman Coluber constrictor flaviventris Say Masticophis flagellum flagellum (Shaw) Elaphe guttata emoryi (Baird & Girard) Elaphe obsoleta obsoleta (Say) Elaphe obsoleta spiloides Du- méril, Bibron, & Duméril Elaphe vulpina vulpina (Baird & Girard) Pituophis melanoleucus sayi (Schlegel) Lampropeltis calligaster calli- gaster (Harlan) SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 17 Lampropeltis getulus holbrooki Stejneger Lampropeltis getulus niger (Yarrow) Lampropeltis triangulum trian- gulum (Lacépéde) Lampropeltis triangulum syspila (Cope) Cemophora doliata (Linnaeus) Thamnophis sauritus proximus (Say) Thamnophis radix radix (Baird & Girard) Thamnophis sirtalis sirtalis (Linnaeus) Thamnophis sirtalis semifasci- ata (Cope) Tropidoclonion lineatum tum (Hallowell) Virginia valeriae elegans (Ken- nicott ) Storeria dekayi wrightorum Trapido Storeria occipitomaculata occipi- tomaculata (Storer) Natrix cyclopion cyclopion (Dumeéril & Bibron) Natrix erythrogaster flavigaster Conant Natrix erythrogaster neglecta Conant Natrix grahami (Baird & Gir- ard) Natrix kirtlandi (Kennicott) Natrix rhombifera rhombifera (Hallowell) Natrix septemvittata (Say) Natrix sipedon sipedon (Lin- naeus ) Natrix sipedon pleuralis Cope Natrix sipedon confluens linea- Blanchard Tantilla gracilis hallowelli Cope Family Crotalidae Agkistrodon piscivorus leucos- tomus (Troost) Agkistrodon contortrix mokeson (Daudin) Sistrurus catenatus catenatus (Rafinesque ) Crotalus horridus horridus Linnaeus The preceding check list contains 109 named species and subspecies of amphibians and reptiles known in Illinois. The numer- 18 Ittinois NarurAL History SurvEY BULLETIN Vol. 28, Art. 1 Table 1—Number of species and subspecies in the herpetofauna of Illinois and some other states. INDIANA (MINTON, KANSAS rome = GEORGIA Group ILLINOIS Persona | (H.M.SmirH p (MartTor Communi 1956) ot 1956) CATION) : 1944) Salamandersrs eon. oa ees 19 20 10 5 57 Mrogs and toags. 22.) eestor 21 14 24 1 34 artless 220 oie eee iP 15 13 8 35 Neazatds sin ies ctw pease ere ike 6 6 16 3 15 NARS voice ska alee See 46 33 46 16 59 rnicodlians 025 cols cc ae eee 0 0 0 0 3 DOME ate oe oe ey ale Ree eee 109 88 109 45 203 ical distribution of species and subspecies in each group for Illinois and for some other states that have been recently surveyed are shown in table 1. Species Deleted From the Illinois List In recent years the natural range of a species of amphibian or reptile has become increasingly dificult to determine because numerous individuals have been carried by human agency into areas new to them. Many snakes, turtles, and lizards have been captured by travelers, taken from their nat- ural ranges, kept for a while as pets, and then released or allowed to escape. More than a dozen extralimital species of am- phibians and reptiles, obviously escapees, re- leased pets, or “banana-bunch” waifs, have come to my attention in the course of this survey, and perhaps there are many more never reported to a biologist. Although re- ports of the alligator and boa constrictor in Illinois are rather easily dismissed, reports of other species may be troublesome to eval- uate. The evaluation of numerous museum specimens for which the locality data are suspected of being in error presents a seri- ous problem. Some errors result from lack of accuracy in cataloging, others from care- lessness in storing or labeling specimens. Many of these errors are introduced into the literature by specialists who study the specimens and cite the locality data, even though the data appear to be dubious. Errors are perpetuated by other specialists who cite the published records. On the basis of our present knowledge, the Illinois rec- ords for the following species are regarded as having been based on error, and these species are here excluded from the list of Illinois amphibians and reptiles until addi- tional evidence is available. Pseudotriton ruber ruber (Latreille).— This eastern salamander has had an unusu- ally complicated history. Yarrow (1882a) cited a specimen of Spelerpes ruber from Aux Plaines, Illinois. The species was credited to Illinois by Davis & Rice (1883a), Hay (18872), and H. Garman (1892) on the authority of Yarrow. The confusion of P. ruber and another red salamander, maculicaudus (equals Eurycea lucifuga) probably led to the as- sumption by Stejneger & Barbour (1917) that P. ruber occurred in Illinois. Dunn (1926) questioned the Aux Plaines record, and Schmidt & Necker (1935) deleted the species from the known fauna of the Chi- cago area. However, Goodnight (1937), on the authority of Yarrow, included the spe- cies in his key. The Aux Plaines locality is almost 400 miles northeast of the west- ernmost generally accepted record for the species, and no specimens are known from other parts of Illinois, from Indiana, or from western Kentucky. Accordingly, P. ruber should be dropped from the list of Illinois salamanders. Pseudobranchus striata (Le Conte).—H. Garman (1892) remarked: “So many south- ern species inhabit the south part of the State that it would not be surprising if Pseudobranchus striata should also be found to occur there.” The species has, however, never been found north of southern Geor- gia. Hyla squirella Bosc—The squirrel tree- frog was credited to Illinois by Davis & Rice (18832), H. Garman (1892), Hart & November, 1961 Gleason (1907), Cagle (1941), Brown (1950), and Schmidt (1953). The early references to the species in the state were probably based on misidentified specimens of related hylids; the later references may have been based on the assumption that squirella occurred in extreme southern IIli- nois in view of its alleged occurrence in western Kentucky. Recently, at the sugges- tion of Roger Conant and through the cour- tesy of Roger Barbour, I examined the Ken- tucky specimens and found them to be aber- rant specimens of Pseudacris triseriata feri- arum. The nearest valid record of H. squir- ella is approximately 300 miles south of Illinois, and the species should therefore be dropped from the list of Illinois amphibians. Sternothaerus carinatus (Gray).—This Gulf Coast species was reported as occur- ring in Illinois by Davis & Rice (1883a, 18834), Jordan (1888), H. Garman (1892), and Hay (1892a), but it was correctly de- leted from the list of Illinois turtles by Cahn (1937). Terrapene carolina triunguis (Agassiz). —The evidence for deleting this subspecies is presented in the discussion of geographic variation of JT. c. carolina on page 135. Chrysemys picta dorsalis Agassiz——The evidence for deleting this subspecies is pre- sented in the discussion of geographic vari- ation of C. p. marginata on page 140. Chrysemys picta picta (Schneider) .— Yarrow (1882a) recorded the eastern painted turtle from Mount Carmel, and H. Garman (1890) questioned the record. Cahn (1937) deleted the subspecies from the Illinois list. Clemmys insculpta (Le Conte).—The be- lief that the wood turtle might be found in northern Illinois was expressed by Stej- neger & Barbour (1933, 1939, 1943), Dit- mars (1936), Cahn (1937), Logier (1939), Breckenridge (1944), and McCauley (1945). Cahn summarized the possibility that the species might occur in this state, pointing out that a record is extant from a locality only 11 miles north of the Wiscon- sin-Illinois state line. There is, however, some question about this record, and C. in- sculpta should be dropped from the known turtle fauna of Illinois until additional evi- dence is available. Trionyx ferox ferox (Schneider).—Ken- nicott (1855) included this southern turtle in his Cook County list, but his specimen SmiTH: AMPHIBIANS AND REPTILES OF ILLINOIS 19 undoubtedly belonged to J. spinifer spini- fer, as Schmidt & Necker (1935) pointed out. H. Garman (1892) presumed that ferox might occur in the Ohio and Missis- sippi rivers, but Neill (1951la) showed that ferox is unknown north of southern Geor- gia. Phrynosoma cornutum (Harlan).—Dit- mars (1907) included western Illinois in the range of the Texas horned lizard, al- though his inclusion was presumably based on nothing more than a guess. Several specimens of this lizard have been found in Illinois, most of them in urban areas, but these are almost certainly irregulars in the fauna, inasmuch as P. cornutum is one of the most popular of reptile pets. Carphophis amoenus amoenus (Say).— The references to Carphophiops amoenus in Illinois by Garman (1892), Cope (1900), Jordan (1929), and Ditmars (1929) were based on atypical or misidentified specimens of the subspecies helenae. ‘These references antedate the present subspecies concepts; amoenus is now known to be replaced by helenae west of the Appalachians. Abastor erythrogrammus (Holbrook).— Robert Ridgway was apparently responsible for inclusion of Illinois in the range of the rainbow snake by Jordan (1878, 1888), Cope (1877, 18952), S. Garman (1883, 1884), Davis & Rice (1883a), and H. Gar- man (1892). There is no other evidence that the species occurs north of Louisiana in the Mississippi River valley. Heterodon simus (Linnaeus).—The re- ports of the southern hognosed snake in Illinois by Davis & Rice (1883a), Jordan (1888), H. Garman (1892), Hart & Glea- son (1907), and Van Cleave (1928) un- doubtedly refer to H. nasicus. The species simus is now known to occur no closer to Illinois than coastal North Carolina. Lampropeltis calligaster rhombomaculata (Holbrook).—The reports of the mole snake in Illinois by Davis & Rice (1883a, 18835), H. Garman (1892), and Jordan (1888) undoubtedly refer to misidentified specimens of L. c. calligaster. The latter subspecies replaces L. c. rhombomaculata in the areas north and west of eastern Mis- sissippi. Lampropeltis triangulum elapsoides (Hol- brook).—The Illinois references to this southern snake (Davis & Rice 1883a, 18836; Jordan 1888; H. Garman 1892) 20 Ittinois NarurAL History SurvEY BULLETIN belong in the synonymy of L. ¢. syspila. L. t. elapsoides occurs no closer to Illinois than eastern Kentucky. Coluber constrictor constrictor Linnaeus. —The evidence for deleting this subspecies is presented in the introductory remarks con- cerning subspecies of Coluber constrictor on page 196. Elaphe guttata guttata (Linnaeus).—The corn snake was reported as occurring in “southern Illinois’ or at Mount Carmel by Yarrow (1882a), Davis & Rice (1883), Hay (1887, 1892a), H. Garman (1892), Cope (1900), Myers (1926), Van Cleave (1928), Minton (1944), and Perkins (1949). All of these authors, however, merely presumed that the corn snake might occur in the state, or cited Yarrow (1882a) as authority for inclusion of Illinois in the range of the species. Schmidt & Necker (1935) deleted the species from the list of Chicago area reptiles. Of the generally ac- cepted records of E. g. guttata, the nearest to Illinois is for specimens from Edmonson County, Kentucky. Although the existence of a population of this species in southeast- ern Illinois is possible, it is much more likely that early authors confused this snake with the superficially similar Lampropeltis calligaster. Virginia striatula (Linnaeus). — The brown snake was credited to Illinois by Cope (1877), Davis & Rice (1883a, 18834), H. Garman (1892), Van Cleave (1928), Cagle (1942a), and Ditmars (1945). Cagle (1941) noted that Illinois specimens were lacking, but he believed the species might occur in southwestern Illinois. Mar- lin Perkins of the Chicago Lincoln Park Zoo stated that he saw the species near Murphysboro, and his recollection was cited by Ditmars and Cagle. His visual record is highly questionable, however, in- asmuch as J’. striatula can be distinguished with certainty from J’. valeriae only with the aid of a magnifying lens. Accordingly, it seems advisable to delete this species from the list of Illinois snakes. Virginia valeriae valeriae (Baird & Gir- ard).—Yarrow (1882a), Hay (1892a), and Cope (1900) undoubtedly misidentified specimens of J’. v. elegans when they re- corded the nominate subspecies in Illinois. V. v. valeriae does not occur west of south- ern Ohio, being replaced by the subspecies elegans in the Midwest. Vol. 28, Art. 1 Thamnophis elegans hammondi (Kenni- cott)—Wright & Wright (1952) men- tioned that an old record for “Tropidonotus hammondi” in Illinois had been published. They listed this among the problematical records, and I have been unable to find the original paper on which the record is based. There can be no doubt that either T. sirtalis or JT. radix was mistaken for hammondi, which is a coastal California subspecies. Thamnophis elegans vagrans (Baird & Girard)—The Rocky Mountain garter snake was included in Illinois reports by Davis & Rice (1883a), H. Garman (1892), and Wright & Wright (1952). Undoubt- edly, a specimen of J. sirtalis was misiden- tified as JT. e. vagrans. Thamnophis butleri (Cope).—Ditmars (1922) noted that Butler’s garter snake oc- curred in eastern Illinois. Davis (1932), having examined the large series of Tham- nophis in the Chicago museums, pointed out that there were no Illinois records of butleri. Necker (1938), Ditmars (1939), Cagle (1941), A. G. Smith (1951), and Wright & Wright (1952) nevertheless pre- sumed that the species was to be found in northeastern Illinois. Conant (1950) pointed out JT. butleri was unknown in Illinois, al- though colonies exist in Wisconsin and southern Michigan. In view of the hun- dreds of garter snakes available from the Chicago area and the absence of specimens of T. butleri, I believe the species should be dropped from the list of Illinois reptiles. Thamnophis sauritus sauritus (Lin- naeus).—The evidence for deleting this subspecies is presented’ in the discussion of geographic variation of J. s. proximus on page 226. Thamnophis sirtalis parietalis (Say).— The evidence for deleting this subspecies is given under the discussion of geographic variation of JT. s. sirtalis on pages 231-2. Natrix rigida (Say)—Davis & Rice (1883a), Jordan (1888), and Wright & Wright (1952) mentioned Illinois in defin- ing the range of this Gulf Coast water snake.. It is almost certain that Davis & Rice misidentified a specimen of N. gra- hami or N. septemvittata and that, on their authority, other authors listed the species as occurring in the state. Natrix sipedon fasciata (Linnaeus).— The inclusion of this name in the Illinois literature is probably due to the confusion in November, 1961 the nomenclature of N. sipedon races rather than to misidentification of specimens. Hur- ter (1911), Loding (1922), and Haltom (1931) apparently applied the name fasciata to the race now known as confluens; Davis & Rice (18832), H. Garman (1892), Gaige (1914), and Wright & Wright (1952) to the race now known as pleuralis. N. s. fas- ciata, aS now understood, does not occur north of Louisiana in the Mississippi valley. Micrurus fulvius subsp—Ditmars (1939) and Cagle (1941) recorded the coral snake as occurring as far north as southern IIli- nois. Pope (1944a) excluded Illinois from the range of the species. Perkins (1949) noted that a dubious record of M. f. fulvius exists from southern Illinois. Although there are old records for the coral snake in Ohio and Indiana, Conant (1951) and Link (1951) have shown rather conclusively that these specimens were probably transported from more southern localities. One specimen (SIU 440) labeled “Cairo” is in the collection of Southern Illinois Uni- versity. This example, a female with a total length of 513 mm., has 15 scale rows, 209 ventrals, 40 caudals, 7 upper and lower labials per side, 11 black body bands, and 3 black tail rings. No other data accompany the specimen except “Cairo” on an outside label. Since the nearest unquestionable rec- ord for the species is in central Arkansas, I am inclined to believe that the specimen was probably collected farther south and subsequently placed in a bottle which hap- pened to bear the label “Cairo.” Agkistrodon contortrix contortrix (Lin- naeus).—The evidence for deleting this sub- species is presented in the discussion of geo- graphic variation of 4. c. mokeson on pages 266-7. Sistrurus miliarius streckeri Gloyd.—A. E. Brown (1901) expressed the possibility that the pigmy rattlesnake might extend eastward to southwestern Illinois. Until the species is found in Illinois or at least adjacent localit’es in Missouri, it should not be included in the Illinois fauna. Crotalus horridus atricaudatus Latreille. —The evidence for deleting this subspecies is presented in the discussion of geographic variation of C. h. horridus on page 271. In addition to species credited to Illinois in the literature, I have seen specimens of such obvious waifs as the caiman and py: thon. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 21 Class AMPHIBIA Salamanders and Frogs Amphibians probably were derived from Crossopterygian fishes early in the Devo- nian Age. They share with the Crossoptery- gians a great many anatomical similarities; also, they possess numerous distinguishing characters, most of which are adaptations for a life on land rather than in the water. There are relatively few modern amphib- ians. The fossil record is sufficiently good to allow recognition of about 10 extinct orders in addition to the three living orders. Two subclasses of amphibians are recog- nized, the Lepospondyli and the Apsido- spondyli. The subclass Lepospondyli con- tains two living orders, the Gymnophiona (caecilians of the tropics) and the Caudata (salamanders). “The subclass Apsidospon- dyli contains one modern order, the Sali- entia (frogs and toads). The relationships of the subclasses, or- ders, suborders, and families represented in Illinois may be summarized in the follow- ing synopsis. Subclass LEepospoNpyLI.—Vertebral cen- tra formed directly from mesenchyme; arcualia partially ossified. Order Caupata.—Tail well devel- oped; at least two limbs present. Suborder CRyPTOBRANCHOIDEA.— Angulare free; gill slits present; external gills absent. Family CryPToBRANCHIDAE. — Large; flattened; wrinkled; free. fleshy flanges on limbs. Suborder AMBYSTOMATOIDEA.—An- gulare and articulare fused; gill slits and external gills usually ab- sent in adult stage. Family AMBysTOMATIDAE.—Lungs and costal grooves present. Suborder SALAMANDROIDEA.—Para- sphenoid teeth present; gills usu- ally absent in adult stage. Family SALAMANDRIDAE. — Costal grooves and nasolabial grooves absent; vomeropalatine teeth in long, posteriorly diverging series. Suborder PLETHODONTOIDEA.—Lungs absent; vomerine and_ palatine teeth usually present. Family PLETHODONTIDAE.—Costal grooves and nasolabial grooves present. bo bo Family AMPHIUMIDAE. — Limbs much reduced; toes 3-3 or less. Suborder Murasiria. — Angulare and prearticulare fused; no maxil- lary bone; pterygoid and palatine teeth in continuous series. Family ProreipAr.—Large aquatic salamanders, each with 3 pairs of bushy, red gills; toes 44; no nasolabial grooves. Suborder MEaAntTEs.—External gills present; no hind limbs. Family SrRENIDAE.—Teeth absent; toes 40; margins of jaws with horny sheaths. Subclass ApsIDOSsPONDYLI.—Vertebral cen- tra formed from subdivision of the sclerotome; arcualia cartilaginous. Order SALIENTIA.—Tail typically ab- sent in adult stage; pelvic girdle and enlarged hind limbs modified for jumping. Suborder ANoMocoELA.—Sacral ver- tebrae procoelous, fused to coccyx; eight presacral vertebrae uniform- ly procoelous or amphicoelous. Family PELoBATIDAE.—Cutting tu- bercle on metatarsus; cranial crests absent. Suborder ProcorLta.—Sacral and pre- sacral vertebrae uniformly procoe- lous; free urostyle; sacral verte- brae with two condyles. Family Buronimar.—Teeth ab- sent; Bidder’s organ in both sexes. Family Hy.ipar.—Teeth present; intercalary cartilages and _ toe pads present. Suborder D1pLastocozLa.—Eight ver- tebrae; sacral vertebrae _bicon- cave; presacral vertebrae procoe- lous. Family RANIDAE.—Vomerine teeth present; no transverse fold of skin on head; tympanum usually distinct; mouth large. Family MicroHyYLIDAE.—Vomerine teeth absent; transverse fold of skin behind head; tympanum us- ually invisible; head narrow and mouth small. For ease in identification, the Illinois spe- cies of Amphibia are diagnosed in two large keys, the salamanders (the order Cau- data) in one and the frogs and toads (the Ittinoris NATURAL History SurvEY BULLETIN order Salientia) in the other. Illinois rep- | resentatives of these two orders may be sep- arated as follows: Tail absent in adult stage; hind legs conspicu- ously large and modified for jumping...... PR AR EES Order Salientia, p. 66 Tail present in adult stage; hind legs not conspicuously large and modified for jump- TAG «cs eek ee Order Caudata, p. 22 Order CAUDATA Salamanders Nineteen species and subspecies of sala- manders occur in Illinois. Another species, Amphiuma means Garden, has been in- cluded in the key, as it may eventually be found in the southern part of the state. Most salamanders are terrestrial as adults, fig. 9, and aquatic as larvae, but even the adults are chained to moist habitats by their susceptibility to desiccation. A few salamanders remain in water throughout their lives; these are permanently gilled species, which are termed neotenous. The species occurring in Illinois range in size from the 4-inch Hemidactylium to the 24- inch Cryptobranchus. Most species are noc- turnal; they remain hidden under logs or rocks during the day and come forth to search for food at night, when the relative humidity is higher. Salamanders are preda- tory, feeding chiefly on those invertebrates most readily available. They are rather sluggish in their movements and harmless to man. Their defense when captured con- sists of secreting slime. Some salamanders, like lizards, readily lose their tails, which they use as means of escape. While a pred- ator is occupied by a detached, wriggling tail, the animal to which the tail belonged may escape by crawling away. A few sala- manders can climb; some can jump by vio- lently uncoiling their bodies. Typically, the seasonal life history of sal- amanders begins with a spring migration to a pond, the males usually preceding the fe- males by a day or so. When the females arrive, a nuptial dance ensues, the males swimming over the females and nudging them from time to time. Males deposit sperm packets known as spermatophores on submerged sticks or vegetation, and the fe- males receive these packets with their cloacal lips, fertilization thus being internal. The females attach their eggs, each surrounded Vol. 28, Art. 1m 5 November, 1961 by concentric layers of jelly, to vegetation or debris in the water. In a few days to sev- eral weeks, gilled larvae hatch from the eggs and each larva rather quickly develops four legs. Typically, metamorphosis occurs in a few months. The newly transformed adults are difficult to identify for a few days before the characteristic features of mature adults appear. There are several departures from this typical life cycle. At least one species prac- tices external fertilization, the male deposit- ing sperm over the newly laid eggs in the manner of most fishes. Some species differ in having a fall mating and fall oviposition. It is not certain that in all species the fe- male picks up the entire spermatophore, and it is probable that in some species sperm cells escape from the packet and swim into the vent of the female salamander. In a few species the eggs are laid near a stream or pond, and the hatchlings must crawl to water or wait until the hatching site is flooded by rains. The most striking devia- tion from the typical life cycle is found in the genus Plethodon. In all species of this genus, the larval period is spent within the large eggs, which are deposited in rock crevices or rotten logs on land. At hatching the miniature salamanders are ready for a terrestrial existence. Other variations in life histories are noted in the habits sections of the following species accounts. Eight of the 19 Illinois salamanders are predominantly eastern in distribution, occur- ring in Illinois in the Wabash Border coun- ties and in some cases extending varying distances northward or southward in the Mississippi River valley but circumventing the central prairie. One of the eastern spe- cies, Desmognathus fuscus, has apparently entered Illinois via the Mississippi River valley, since the nearest record outside IIli- nois is in western Kentucky rather than In- diana. The eight eastern components are Cryptobranchus alleganiensis, Ambystoma maculatum, A. opacum, Eurycea bislineata rivicola, E. longicauda longicauda, Pletho- don dorsalis, P. glutinosus glutinosus, and Desmognathus fuscus. Three species, Ambystoma texanum, A. tigrinum, and Eurycea longicauda melano- pleura, have ranges centering to the west of Illinois. The first two species are rela- tively wide ranging and they completely traverse Illinois. The third is an Ozark SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 23 species found only in the extreme western part of the state. Three species, Ambystoma talpoideum, Notophthalmus viridescens louisianensis, and Siren intermedia nettingi, are clearly south- ern animals. The first species extends north- ward along the Mississippi River to the southern tip of the state; Siren extends northward along the major rivers in the southern two-thirds of Illinois; Notophthal- mus occurs as far north as the northern boundary of the state. Three species, Ambystoma laterale, Pleth- odon cinereus cinereus, and Hemidactylium scutatum, northern in distribution, extend southward into Illinois. Two species cannot be classified accord- ing to distribution. Necturus maculosus maculosus has a range in which Illinois is approximately centered. Eurycea lucifuga is unassignable because of the peculiar re- striction of this species to areas containing limestone caves. Key to the Order Caudata (Salamanders) 1. One pair of legs (Sirenidae)...........-. RSs Ben Cie Siren intermedia nettingt Two pairs of legs. 2. Legs vestigial; 3 or fewer toes; body eel- like (Amphiumidae) EEN Amphiuma means “‘tridactylum Legs well developed; 4 or more toes, body not eel-like 3. Four toes on each hind foot Five toes on each hind foot............5 4, Feathery external gills; total length to 18 inches (Proteidae) Byars t Necturus maculosus maculosus No external gills; total length less than 4 inches (Plethodontidae) Beet Le ve wets Hemidactylium scutatum 5. Body flattened and longitudinally wrin- kled; one gill slit on each side of neck; toes with free fleshy margins, fig. 10 (Cryptobranchidae ) Cryp- tobranchus alleganiensis alleganiensis Body terete, not wrinkled; no gill slits; toes without fleshy flanges CPE SOE 6 6. Costal grooves present, fig. 9 .......... 7! Costal grooves absent (Salamandridae) . Notophthalmus viridescens louisianensis 7. Nasolabial grooves absent, fg. 11 leas stomatidae) ...... Nasolabial grooves present, ‘fig. 12 (Pleth- Od ONE ae) iy Coens see erie nage 16 8. Premaxillary teeth in two or more series; neck distinctly wider than head; lingual plicae at oblique angles to median longi- tudinal furrow, fig. 13 Ni ccrebae ate eras aon Ambystoma texanum 24 Inuinois Natura History SurvEY BULLETIN COSTAL FOLDS GROOVES COSTAL Vol. 28, Art. 1 emis Fig. 9.—Lateral view of a salamander, Ambystoma texanum. Premaxillary teeth in a single series; head wider than neck; lingual plicae radiat-, fig. 14 9. Pattern consisting of 4 to 8 silvery white crossbands on dorsum ‘Tod: Ambystoma opacum Pattern not consisting of white cross- bands eee 10. Body long and slender ; ‘toes of adpressed limbs barely overlapping. Ambystoma laterale Body atoue: toes of adpressed limbs over- lapping by length of longest finger or 1] more 11. Groundcolor black or brown, with yellow spots 12 Groundcolor black or brown, without yel- low spots 13 12. Two dorsolateral rows of subequal yellow spots; venter and lower sides brown and unspotted Ambystoma maculatum Irregularly spaced and unequal yellow spots on back and sides and often on venter...Ambystoma tigrinum tigrinum 13. Head width 23 per cent or more of snout- vent length Ambystoma talpoideum Head width less than 23 per cent of snout- vent length 14 14. Snout-vent length over 50 mm.; dark or with brassy flecks Immature Ambystoma tigrinum tigrinum Snout-vent length under 50 mm.; _ back dark and with or without flecks . 15 15. Dorsum brown, often with brassy flecks; venter yellow or white . SARL ap Immature Ambystoma maculatum Dorsum black or brown, often with ir- regular white blotches; venter brown Immature Ambystoma opacum 16. Light line from eye to angle of jaw, fig. 15; tail triangular in cross section Desmognathus fuscus conanti No light line from eye to angle of jaw: tail not triangular in cross section 17 17. Tongue with a central pedicel, free all Figs. 10-15.—Characteristics of salamand- rs: 10, hind foot of Cryptobranchus allegan- iensis; 11, face view of Ambystoma opacum; 12, face view of Plethodon glutinosus ; 13, open- mouth view of Ambystoma texanum; 14, open- mouth view of Ambystoma opacum; 15, head of Desmognathus fuscus; c, choana; e, external naris; /, lingual plica; m, maxillary teeth; 2, nasolabial groove; ~, premaxillary teeth; ¢, tongue; v, vomerine teeth. A dissecting micro- scope is necessary to see most of these struc- tures. November, 1961 around; groundcolor of dorsum yellow, orange, or red; venter yellow or white 3S OCT ON Cae oe ee ols Tongue attached in front, free behind and at sides; groundcolor of dorsum black, brown, or dark gray; venter gray, brown, or black. . 21 18. Three or more costal folds between ad- pressed limbs; yellow, with brown dor- solateral stripes Eurycea bislineata rivicola Two or fewer costal folds between ad- pressed limbs. ease se 19 19. Body red or red-orange, with numerous irregular black spots or dashes scattered over back and sides Lurycea lucifuga Body yellow or orange-yellow, with dis- tinct dorsolateral stripes .. 20 20. Sides of tail with many vertical dark bars Eurycea longicauda longicauda Sides of tail dark and without vertical bars Eurycea longicauda melanopleura 21. Costal grooves 15 or fewer; belly uni- form gray or black; back flecked with white; maximum length 180 mm. Plethodon glutinosus glutinosus Costal grooves 16 or more; belly usually mottled; back not spotted with white; maximum length 110 mm. 22 22. Middorsal red, orange, or yellow longi- tudinal stripe 23 No middorsal red, orange, or yellow stripe 5 25 23. Middorsal stripe zigzag in shape Plethodon dorsalis Middorsal stripe with straight edges 24 24. Costal grooves 16-19, usually 17; tail usually less than snout-vent length: middorsal stripe usually widest on base of tail Plethodon dorsalis Costal grooves 17-20, usually 19; tail usually longer than snout-vent length; middorsal stripe widest at mid-body Plethodon cinereus cinereus and breast region with red costal grooves usually 17 or 18; tail usually less than snout-vent length Plethodon dorsalis Fore legs and breast region without red markings; costal grooves usually 18 or 19; tail usually longer than snout-vent length Plethodon cinereus cinereus CRY PTOBRANCHIDAE 25. Fore legs su‘usion ; This family contains two genera of large, permanently aquatic salamanders, one of which occurs in the Orient and the other in the eastern United States. Cryptobranchus Leuckart Two subspecies are currently recognized in this monotypic genus. The nominate race, which occurs in extreme eastern IIlinois, is widespread in eastern North America: the other race is confined to Ozarkian SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 25 streams of southeastern Missouri and adja- cent Arkansas. Cryptobranchus alleganiensis alleganiensis (Daudin) Hellbender Salamandra_ alleganiensis Daudin 1803:231 (type locality: Allegheny Mountains in Virginia). Cryptobranchus alleganiensis, Goodnight 1937: 301. Menopoma allegheniense, Davis & Rice 1883a: 26. Menopoma alleghaniensis, Brendel 1857:254. Cryptobranchus alleghaniensis, H. Garman 1892 :380-1. Diagnosis.—A large aquatic salamander (largest Illinois specimen 440 mm. in total length), fig. 16, with a flattened, much wrin- kled body; 5 toes on each hind foot; loose folds of skin along sides of body and pos- terior margins of legs; 1 gill slit on each side of throat; dark dorsum and slightly less dark venter; without external gills. Variation.—Bishop (1941) found that males of this species were proportionately broader bodied and heavier than females. During the breeding season, the male can be recognized by the swollen ridge sur- rounding the vent. Bishop (1941) believed that transforma- tion occurs in the second year. The newly transformed hellbenders differ from large adults by their more prominent black spots. Four Illinois specimens are extant. One of these, CAS 294, is obviously very old and is accompanied only by the label “south- ern Illinois.” It is a female, 225 mm. in snout-vent length; although faded, it still has scattered inky flecks on the dorsum and sides of the tail. Three recent specimens, reported by Stein & Smith (1959), range from 267 to 285 mm. in snout-vent length, 418 to 440 mm. in total length; internar- ial distances are 2.0, 2.2, and 3.5 times the spiracular diameters. Two of the three are bluish slate in color; one is dirty brown; two are uniformly colored except for very faint mottling; one is minutely flecked with olive. One (from the Ohio River at Cave in Rock) has rather heavy pigmentation on the lower jaw and a spiracle diameter of only 4.5 mm. and thus approaches the Ozarkian race, Cryptobranchus alleganien- sis bishopi. The others are in every way typical of the nominate subspecies; in dor- 26 Intinois NarurRAL History SuRVEY BULLETIN sal pattern, one of the most reliable subspe- cific characters, all four Illinois specimens are assignable to C. a. alleganiensis. Habits.—The hellbender is permanently aquatic, occurring in fast-running water of rivers and large creeks. Although essen- Vol. 28, Art. 1 twisted into a single rosary-like string. Egg masses deposited by several females may be found under one flat rock. The nest site may be attended by a male who aerates the eggs by his movements. Eggs laid in mid- September hatch in mid-November. Dur- Fig. 16.—An adult Cryptobranchus alleganiensis alleganiensis from Harrison County, Indi- ana. (Photo by Isabelle Hunt Conant.) blotches are black. tially nocturnal, in the spring many of these salamanders are caught on baited hooks during the day. According to Bishop (1941), the lungs of the hellbender are well devel- oped, and captive individuals rise to the sur- face at intervals to gulp air. Hellbenders are ugly in appearance and unpleasant to handle because of their ex- treme sliminess. In food habits they are predatory, eating crustaceans, fishes, mol- lusks, insects, and even their own eggs and young. Bishop (1941), who summarized the life history of C. a. alleganiensis, noted that in the eastern United States breeding aggrega- tions are found in August. Fertilization is external. Approximately 300 to 400 eggs, each of which is about 6 mm. in diameter and surrounded by concentric rings of jelly, are laid in multiple strands, which become The groundcolor is slate gray; the scattered irregular ing the 2-year larval period, the young hell- benders, which are gilled, gradually acquire the characteristics of the adults. Illinois Distribution Although C. a. alleganiensis was long presumed by many authors to occur in Illinois waters, actual specimens with locality data were not avail- able until recently. Prior to 1900, the sev- eral references to the species apparently were based on hearsay records of fishermen and on the likelihood that the species oc- curred in the Ohio River down to the mouth of the Wabash River. Blatchley (1899) mentioned a Vigo County, Indiana, speci- men presumably taken in the Wabash River. Stein & Smith (1959) summarized and evaluated all of the reports for Illinois. Unquestionable recent records for the Ohio and lower Wabash rivers bordering Illinois indicate that the species occurs in the south- November, 1961 Fig. 17.—Distribution of Cryptobranchus al- leganiensis alleganiensis. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. The Blatchley record referred to on page 26 is not plotted. eastern part of this state and may ascend short distances up the major tributaries of the Ohio and Wabash rivers, fig. 17. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: LAwrRENCE County: Lawrenceville, Wa- bash River at Vincennes [Indiana] (Stein & Smith 1959) ; Putasxr County: near Ullin (Stein & Smith 1959). AMBYSTOMATIDAE The family includes three genera in the United States and Canada, two of which are confined to the Pacific Northwest and one of which is transcontinental. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS Pal Ambystoma Tschudi This North American genus contains 12 species known in the United States and Can- ada; several of these species consist of two or more subspecies. Six species and sub- species occur in Illinois. Ambystoma laterale Hallowell Blue-Spotted Salamander Amblystoma laterale Hallowell 1858:352 (type locality: borders of Lake Superior near Marquette, Michigan). Amblystoma jeffersonianum laterale, Davis & Rice 1883a:26. Ambystoma laterale, Minton 1954:178. Amblystoma jeffersonianum nec Green, Davis & Rice 1883a:26. ?Amblystoma jeffersonianum jeffersonianum nec Green, Jordan 1888:178. Ambystoma jeffersonianum nec Green, Hay 1892a:431. Amblystoma jeffersonianum fuscum, H. Gar- man 1892:372-3. ?Plethodon glutinosus nec Green, Shelford 1913:181, 183. Diagnosis—A medium-sized, — slender, dark brown, black, or blue-black salaman- der (largest Illinois specimen 124 mm. in total length), fig. 18, with discrete pale blue or bluish white flecks on venter, sides, and sometimes on the dorsum; usually 12 or 13 costal grooves, counting impressed lines in groin and axilla; toes of adpressed limbs separated or overlapping by no more than | costal fold; head of moderate size, distinctly wider than neck. Variation.—Males of this species pos- sess greatly swollen vents during the breed- ing season. At other times the sexes are dificult to distinguish. Minton (1954) noted that toes of adpressed limbs touch or overlap more frequently in males than in fe- males. The toes of the adpressed limbs touch or overlap by as much as 1| costal fold in speci- mens under 40 mm. in snout-vent length; toe tips vary from an overlap of one-half costal fold to a separation of as much as 3 folds in specimens over 40 mm. Juveniles are relatively larger headed than adults. None of our specimens can be assigned to the related Ambystoma jeffersonianum. In- clusive of the impressed lines in the axilla and the groin, there are 12—12 costal grooves in four specimens, 13-13 in eight specimens, and 14-14 in one specimen. Vomerine teeth 28 ILtino1is NatuRAL History SuRVEY BULLETIN are usually in 4 series, but sometimes the median pair is fused. Vomerine tooth counts for four specimens range from 27 to 39, averaging 32. Maxillary and premaxillary tooth counts for five specimens range from Vol. 28, Art. 1 Stille (19546) found that in the Chicago region the eggs of this species are laid singly or in small clumps attached to litter on the bottoms of the shallow forest ponds. Egg laying occurs in late March and early April. Fig.18—An adult Ambystoma laterale from Lake County, Illinois. The groundcolor is black; vague bluish white flecks are scattered over the lower sides. 76 to 101, averaging 85. Nine of the 14 specimens at hand have discrete light flecks on the sides of their tails as well as on their venters. The tail length ranges from 40.4 to 49.5, averaging 46.5, per cent of the snout-vent length. Habits.——Minton (1954) noted that this species is characteristic of wooded, swampy areas where the soil is sandy and that it may occur in patches of woodland that are sur- rounded by prairie. Like most salamanders, individuals of this species may be found un- der logs or other objects. They are above ground in numbers only during the short breeding season. Their food consists of arthropods and annelids. Hatching occurs approximately a month later, and transformation takes place in late June to mid-August, the time depending on the permanency of the ponds. Reliable in- formation on the life history of the blue- spotted salamander is not available; pub- lished observations concern the related 4m- bystoma jeffersonianum or refer to a com- posite of the two species. Illinois Distribution—This northern species is restricted in Illinois to the north- eastern corner of the state, fig. 19. Yarrow (18822), who first reported it from Illinois, considered its range as state-wide. The re- ported occurrence of 4. jeffersonianum (equals 4. laterale) in southern Illinois is November, 1961 Fig. 19.—Distribution of Ambystoma later- ale. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 29 in error and actually is based on specimens of the superficially similar 4. texanum. The occurrence of the species in the southern half of the state was not challenged by many subsequent authors, probably because of 48 USNM specimens from southern IIli- nois localities cataloged as A. jefferson- ianum. I have examined these specimens (4096 [38] “S. Ill.”; 8837, 12050 [3], 12056 [2], 12058-60 Mount Carmel; 8777 Belle- ville) and have found them to be 4. tex- anum. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map, fig. 19, by hollow sym- bols: LAKE County: Beach, Highland Park (Schmidt & Necker 1935). Ambystoma maculatum (Shaw) Spotted Salamander Lacerta maculata Shaw 1802:304 (type local- ity: Carolina, revised to vicinity of Charles- ton, S. C., by Schmidt 1953). Ambystoma maculatum, Schmidt 1930:10-1. Ambystoma punctata, Kennicott 1855:593. Amblystoma punctatum, Cope 1868:177. Ambystoma punctatum, O'Donnell 1937:1066-7. blue-black, salaman- Diagnosis.—A_ large, stout, slate-colored, or brownish black der (largest Illinois specimen 190 mm. in total length), fig. 20, with 2 rows of yel- low-white or orange-yellow, usually round- ed, spots extending from the head well onto the tail; sides and venter slate color to Fig. 20.—A subadult Ambystoma maculatum from Alexander County, Illinois. The ground- color is dark brown or black; discrete yellow spots tend to be arranged in two rows down the back. 30 Ittino1s NATuRAL History SurvEY BULLETIN Vol. 28, Art. 1 Table 2.—Ontogenetic variation in Illinois Ambystoma maculatum, as illustrated by a series from Alexander County. Figures in parentheses are numbers of specimens. JuvenI_e (8) Apu t (11) CHARACTERISTIC ae Range Mean Range Mean Snout-vent length (mm.)........... Pee b OA 35 2450 ashe 59.0-79 S08 eaten toe Snout-vent length as percentage of total length...| 51.0-60.0 55.0 48.3-52.4 50.0 Number of vomerine teeth.................---- 24-42 332 43-59 52.0 Number of premaxillary-maxillary teeth. ........ 91-117 102.5 108-140 129.0 Position of toe tips with legs adpressed.......... SF ee Aa th Ph ee See oer — 1 eee oe Table 3—Geographic variation in adult Illinois Ambystoma maculatum. Figures in paren- theses are numbers of specimens. SOUTHERN Ivuinors (15) CHARACTERISTIC Range Snout-vent length (mm.)............ Dotalilensthu(mm:.)iics 3. sees ee 112-167 Neoietine (ett. : 68 oo oe tc oe 38-59 Premaxillary-maxillary teeth........ 108-140 ERBOISUSPIOES Ps 2 Sea! hae sme Dees NO 9-17 asta PPGOVES hint poles we uss eae 11-13 brown without irregular yellow spots or blotches; usually 12 costal grooves, some- times 11 or 13; 1 or no palmar tubercles. Variation——During the breeding season the male of Ambystoma maculatum has a greatly swollen vent and darker colored venter. At other seasons, according to Bishop (1941), the female may be recog- nized by a wider, more convex head, greater distance between the fore and hind legs; and a shorter tail. Juveniles have smaller dorsal spots than adults. In specimens less than 40 mm. from snout to vent, the spots are less regularly arranged, less prominent, and no greater in size than the eyes. Specimens 45 mm. in snout-vent length and larger have conspicu- ous yellow spots against a dark ground- color, and the individual spots are larger than the eyes. The chins and venters are yellowish white in juveniles, becoming dark brown or slate color in adults. Also, juve- niles differ from adults in having propor- tionately longer legs, shorter tails, and smaller numbers of teeth. This variation is summarized in table 2. Although meager, the series available for study indicate some geographic variation NorTHEASTERN Ittrnots (10) East-CENTRAL Ivirnors (4) Mean Range Mean Range Mean ee 67-80 |.......+.|° (2-0 arenes 154-170 |..........) 165-190 51.0 35-64 47.5 39-70 5555 129.0. | 122-140 | 128.3 | 127-1615) iaoes 13.0 11-15 1237 14-16 15% 11.8 11-12 11.2 12-13 12.4 within the state. Ten adults from north- eastern Illinois (Lake County) average con- siderably larger in size, possess more teeth and a higher number of body spots, and have a slightly higher average costal groove count than specimens from elsewhere in the state. An occasional specimen has a pair of bright orange spots on the head that are in sharp contrast to the: yellow body spots. Salamanders from other parts of the state sometimes have orange spots on their heads, but the color difference is less conspicuous than in the northeastern specimens. The large number of vomerine and pre- maxillary-maxillary teeth may be directly correlated with the large size of the north- ern salamanders. The other slight differ- ences suggest that two subspecies may be discerned eventually in 4. maculatum. In- trastate variation in the species is sum- marized in table 3. Habits.—According to Pope (19445), 4. maculatum is common in deciduous and mixed woods in northeastern Illinois. Cagle (1942a) reported that it is abundant in low oak-hickory forests adjacent to swamps and creeks in southern Illinois. The species can be found in numbers throughout the November, 1961 summer under logs in the swampy flood- plain forest at Horseshoe Lake in Alexan- der County, where the numerous shallow woodland ponds seemingly afford ideal breeding sites. The spotted salamander re- mains hidden under logs or rocks during the day but may be found wandering about on the forest floor at night. It feeds on arthropods, mollusks, and annelids. Early in the spring spotted salamanders migrate to a woodland pond to congregate and breed. The aggregation performs a sort of nuptial dance, after which the males de- posit spermatophores on sticks and other litter, and the females lay eggs in clusters, usually of several dozen, on debris and vege- tation in the pond. The eggs hatch in less than a month, and the larvae transform be- tween late June and mid-August. Illinois Distribution.—The spotted sala- mander is found in wooded regions in north- ern, eastern, and southern Illinois, fig. 21. Like that of many other eastern forest ani- mals, the range of the species in Illinois is bisected by the Grand Prairie, and popula- tions extend short distances northward from the south and southward from the north in the forested Mississippi River val- ley in western Illinois, but apparently they do not meet. In eastern Il]linois the distri- bution is sporadic; permanent woodland ponds are necessary for the occurrence of A. maculatum. A record (UIMNH 1745) from Urbana, which is in a prairie region, is open to some doubt. The general occurrence of this salaman- der from the Gulf Coast to well into Can- ada indicates that temperature is less im- portant as a controlling factor than the pres- ence of mesic forest. Although the forested areas in central Illinois appear to afford suitable habitat, they tend to become dry in late summer; there is no evidence that the species occupies these regions. The pub- lished record for Macoupin County (Owens 1941) is a misidentification based on two CNHM specimens that are actually 4. tig- rinum. Although undocumented by _ specimens, published records for the following localities are believed valid; most are indicated on the _ distribution map by hollow symbols: Cook County: Palos Park (Schmidt & Necker 1935); Northfield (Cope 1868); Du Pacer County: Wooddale (Stille & Edgren 1948); Union County: Anna- (Cagle SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 31 Fig. 21.—Distribution of Ambystoma macu- latum. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. 19422); Union County State Forest (Min- ton & Minton 1948); WasasH County: Mount Carmel (Yarrow 1882a). Ambystoma opacum (Gravenhorst) Marbled Salamander Salamandra opaca Gravenhorst 1807:431 (type locality: New York). Amblystoma opacum, Cope 1868:175. Ambystoma opacum, Hurter 1911:78. Diagnosis.—A medium-sized, stout, black salamander (largest Illinois specimen 121 mm. in total length), fig. 22, with 3 to 8 silvery to grayish white crossbands on the back and 4 to 8 white rings around the tail; dorsal crossbands widened laterally, usually forming a pair of dorsolateral light stripes; head wide; toes of adpressed limbs touching to broadly overlapping. 32 I_tinois NaruraAt Hisrory SurRvEY BULLETIN Vol. 28, Art. 1 Fig.22.—An adult Ambystoma opacum from Union County, Illinois. The groundcolor is black; the crossbands are white. Variation.— Males of this species can be distinguished from females by the silvery white crossbands which contrast more sharp- ly against the blue-black groundcolor than do the grayish white bands of the females. In preserved specimens the prominently swollen vent of the male, which is larger than that of the female at all seasons, offers the simplest method of determining the sex. Subadults less than 30 mm. from snout to vent are usually quite unlike adults in pat- tern. The chins and venters are light brownish to light slate color, and the dorsal patterns consist of occasional, poorly de- fined, light blotches on the black ground- color and often white “frosting” on the heads and anterior parts of the bodies. The adpressed limbs of this size group overlap by 2 or 3 costal folds. Specimens 30 to 35 mm. in snout-vent length have essentially the patterns of the adults except that the white crossbands anteriorly are less well defined; the venters are blue-black, and the brown or gray chins show evidence of dark- ening. Specimens 40 to 47 mm. in snout- vent length are proportionately shorter- legged, the adpressed limbs overlapping 114 to | costal fold. Individuals 48 mm. and larger in snout-vent length vary in the de- gree of overlap of adpressed limbs from 1 costal fold to barely touching. The number of teeth appears to vary with size of the in- dividual. No definite trends in geographic varia- tion within Illinois have been discerned in this species. Individual variation for a sam- ple of 41 specimens from southern and east- ern Illinois is as follows: snout-vent length 32 to 59 mm.; total length 57 to 121 mm.; number of costal grooves 11 to 13 (average 12.1) ; toes of adpressed limbs varying from barely touching to overlapping by 314 costal folds; number of head and body bands 3 to 8 (average 5.8) ; number of tail rings 4 to 8 (average 6.2); number of vomerine teeth 29 to 63 (average 48.0); number of pre- maxillary-maxillary teeth 79 to 147 (aver- age 110.0). Habits.—A4 mbystoma opacum is a wood- land animal, more tolerant of aridity than A. maculatum but apparently less tolerant of low temperatures. Since fall and winter rains insure floodplain pools that last long enough for the transformation of the opacum larvae, a suitable breeding site is probably less important as a limiting factor for this species than for maculatum. The marbled salamander is usually found in wooded hilly regions and can be collected under rocks and logs throughout the sum- mer, sometimes in surprisingly dry situa- tions. In September individual salamanders migrate onto floodplains or into swamps and may be found, often in abundance, under logs or sticks, in heavily shaded areas sub- ject to flooding with the autumnal rains. At Horseshoe Lake, Alexander County, however, the species is extremely abundant throughout the summer, and it appears at least as successful there, in the floodplain swamps, as in upland areas. The food of the marbled salamander con- sists of arthropods, annelids, and mollusks. The courtship of this species is similar to that of the spotted salamander, except that it takes place in the fall rather than in the spring and on land rather than in the water. The males deposit spermatophores in damp places, and the females pick them up with their cloacal lips; then each female November, 1961 deposits approximately 100 eggs in a pro- tected depression. Incubation depends on the length of time before the eggs are inun- valli + ST ‘er tt, Fig. 23.—Distribution of Ambystoma opac- um. Watching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REpTILES OF ILLINOIS 33 dated, and the hatching time is accordingly variable. Normally, metamorphosis occurs the following June or July. Illinois Distribution.—/. opacum occurs throughout the southern third of Illinois, north along the Indiana-Illinois border probably to Iroquois County, fig. 23, but it appears to be abundant only in the southern fourth of the state. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: RANDOLPH County: (Hurter 1911); Un- 10N County: Cobden (H. Garman 1892) ; WasasH County: Mount Carmel (Yar- row 1882a). Ambystoma talpoideum (Holbrook) Mole Salamander Salamandra_ talpoidea Holbrook 1838:117, pl. 39 (type locality: sea islands on the border of South Carolina). Amblystoma talpoideum, Cope 1868:173. Ambystoma talpoideum, Hay 1892a:582. Diagnosis.—A medium-sized, extremely stout, broad-headed salamander (largest Illinois specimen 114 mm. in total length), fig. 24, blue-black or brownish black and usually unmarked above except for a sug- gestion of a longitudinal light stripe on the basal third of the tail; usually 11 costal grooves, counting the impressed line above the hind limbs; head width 22 to 32 per cent of the snout-vent length; snout-vent length 52 to 58 per cent of total length; toes over- lapping when legs are adpressed; midven- tral dark stripe usually conspicuous. Table 4.—Ontogenetic variation in Illinois Ambystoma talpoideum. Figures in paren- theses are numbers of specimens. Snout-VENT LENGTH (MM.) CHARACTERISTIC 33-40 (5) 41-50 (4) 50-61 (7) Range Mean Range Mean Range Mean Miotalleneth (mm.) ...3..s..6..06: Et JON eSnips bie TAT er eee ORE ek QAI er cites Costal folds overlapped by adpressed EIS St5 Bek so eC eee 4-6 5.1 2.5-4.0 3.3 0.5-2.5 1.6 Meremerine teeth........:........... 36-40 38.5 40-49 43.2 39-65 52.5 Premaxillary-maxillary teeth ....... 82-101 91.4 |101-115 |} -107.3 | 102-124) 115.0 Head width as percentage of snout- SIDE ESTER ANE pease ee eee 26.4-32.1 28.2 |26.1-28.8 27.2 |22.4-25.5 24.5 34 Ittino1s NarurAL History SuRVEY BULLETIN Variation.—During the breeding season Ambystoma talpoideum males may be dis- tinguished from females by their swollen vents. I have not been able to find external characters for sexing specimens taken at other seasons. individuals are proportionately longer-legged, are wider-headed,; are more bluish in color, are more often flecked with gray, and have fewer teeth than adults. These trends are summarized in table 4. Bishop (1941) recorded the maximum length for this species as 97 mm. Four of the 16 Horseshoe Lake, Alexander County, specimens exceed that length, and INHS 5267 is 17 mm. longer than Bishop’s largest specimen. Costal groove counts are 11-11 in 14 specimens and 10-10 in two specimens. Variation in dentition and body proportions is shown in table 4. The usual color is blue-gray, but occasionally large specimens Young Vol. 28, Art. 1 are gray-brown. The midventral dark longi- tudinal stripe may be margined on either side by a light area and a secondary dark lateroventral stripe. In most living speci- mens the dorsal portion of the base of the tail is lighter than the rest of the body. Comparative material from South Caro- lina and Louisiana, lent through the cour- tesy of the late E. B. Chamberlain and of F. R. Cagle, agrees rather closely in most de- tails with Illinois samples. Larvae and adults in the series from South Carolina have a somewhat more prominent ventral pattern, and two of the three Louisiana specimens are at variance with both the Illinois and the South Carolina series in the presence of numerous minute tubercles on the sides of the tails, a condition suggestive of sexual dimorphism. Habits.—The mole salamander is appar- ently similar to the marbled salamander in ; Fig. 24.—Adult Ambystoma talpoideum from Alexander County, Illinois. The groundcolor is dark brown or bluish black; the flecks and often the dorsal crest of the tail are gray. November, 1961 Fig. 25.—Distribution of Ambystoma talpoi- deum. Hatching indicates the presumed range of the species in II]linois; solid circles indicate localities represented by specimens examined during this study; the open circle indicates a locality represented by a published record believed to be valid. The lower map depicts the total range of the species as currently known. habits, as the two species have been found together within or under rotten logs in cy- press swamps. Although as many as five specimens of dA. talpoideum have _ been collected in one day at Horseshoe Lake, Alexander County, this species is decidedly less common than A. texanum, opacum, or maculatum. A. talpoideum presumably feeds upon worms, mollusks, and arthro- pods. Life-history data for this species in IIli- nois consist of one observation of a breeding aggregation on November 8. Mosimann & Uzzell (1952) report that in South Caro- lina oviposition occurs in late December and that the 10 to 41 eggs are in compact masses attached to small sticks and grass stems in shallow ponds. The larval stage is of ap- proximately 3 to 4 months duration. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 35 Illinois Distribution.—/. talpoideum, an uncommon species, is known at present in Illinois only from Alexander, Jackson, Johnson, and Union counties, fig. 25. I have examined the specimens reported by Cagle (1942a) from near Anna and 6 miles south- west of Jonesboro (CAS 2512 and 2002) and have found them to be A. texanum. The range of 4. talpoideum is yet to be delineated in the Mississippi River valley. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: ALEx- ANDER County: Cairo (Cope 1868). Ambystoma texanum (Matthes) Small-Mouthed Salamander Salamandra texana Matthes 1855:266 (type locality: woods near Colorado River and Cummings Creek bottom, Fayette County, Texas; revised to Rio Colorado bottomland by Schmidt 1953). Ambystoma texanum, 19335 275 Amblystoma microstomum, Cope 1868:207. Ambystoma microstomum, Hurter 1911:73. Chondrotus microstomus, Cope 1889:101-3. Ambystoma jeffersonianum nec Green, Hay 1892a:431 (part). Amblystoma jeffersonianum jeffersonianum nec Green, Yarrow 1882a:50. Amblystoma jeffersonianum platineum nec Cope, Yarrow 1882a:151. Ambystoma talpoideum nec Holbrook, Cagle 1942a:175 (part). Stejneger & Barbour Diagnosis.—A moderate-sized, slate-col- ored, blue-black, or brownish black sala- mander (largest Illinois specimen 171 mm. in total length), fig. 26, often with lichen- like patches of gray on the sides of the tail and trunk; head narrow and mouth small; gular region conspicuously swollen and wider than greatest width of head; vomer- ine teeth less than 35 and never extending laterally beyond the choanae; maxillary-pre- maxillary teeth usually in 2 or more rows in front, the continuous series containing less than 100 teeth; toes of adpressed limbs touching in subadults or separated by 1 to 4 costal folds in large adults; costal grooves 13¢t0 15. Variation—Males of Ambystoma tex- anum have prominently swollen vents dur- ing the breeding season. At all seasons, they are slightly smaller and have longer tails, stouter legs, and wider heads than females. 36 Intinors NaruraAt History Survey BULLETIN Vol. 28, Art. 1 Fig. 26.—An adult Ambystoma texanum from Calhoun County, Illinois. The groundcolor is dark brown or black, usually with flecks of gray scattered over the back and sides of the animal. Trends in ontogenetic variation are ex- pressed chiefly by proportions and color and are illustrated by a sample of 22 specimens from Horseshoe Lake, Alexander County, table 5. Geographic variation within Illinois is rather slight. A sample (14 specimens) from the southern tip of the state tends to have smaller individuals, slightly lower tooth counts, and perhaps a higher fre- quency of subadults with distinct gray frost- ing on the dorsum than samples from else- where in the state. In 32 per cent of the 14 southern Illinois specimens a single row of premaxillary teeth is characteristic, whereas in only 6 per cent of 37 specimens from other parts of Illinois is a single row characteristic; 2 or 3 rows are typical. Individual variation for a sample of 51 Table 5.—Ontogenetic variation in Illinois are numbers of specimens. adults is as follows: snout-vent length 50 to 90 mm.; total length 89 to 155 mm.; number of costal grooves 13 to 15 (average 14.2); number of vomerine teeth 18 to 33 (average 25.0); number of maxillary-pre- maxillary teeth 58 to 101 (average 75.0). A specimen from McLean County has a bifid tail, an anomaly due to an injury to the tail of the animal. Habits.—The small-mouthed salamander is the most common Ambystoma in the state. It occurs in woodlands, prairie, pastured areas, and even in the intensively cultivated black soils of central Illinois. Adults are en- countered during the’ summer months in various habitats, such as rocky hillsides, creek beds, and floodplain swamps. They feed on earthworms, slugs, and arthropods. They are nocturnal and fossorial. Ambystoma texanum. Figures in parentheses CHARACTERISTIC Snout-vent length as percentage of total length.............. Joes of adpressed limbs a0 iodine wen ss Number of vomerine teeth.............. Number of maxillary-premaxillary teeth.. ........ Golorofeventen: a.) csaiccscp os srogiccns eon eee Mesa. Snout-VENT LENGTH (mM.) 33-40 (9) | 41-54 (7) | 56-64 (6) 55.6-59.5 | 52.3-57.0 | 49.8-58.0 sates eee Touch —\4 — 2% See een 2 15-27 20-26 18-27 Bae age 32-73 61-77 61-72 BEL Shi aide Light Light or Dark | dark* *Preserved specimens of this size group frequently have sharply bicolored sides. November, 1961 Breeding occurs in late February and throughout March in most of Illinois. Al- most any standing water is apparently suit- able as a breeding site inasmuch as eggs have been observed in ditches, flooded fields, woodland streams, and even in Cis- terns. The egg masses, each usually con- sisting of 6 to 30 eggs, are deposited on sticks or vegetation in shallow water. Often eggs and spermatophores are present on the same object. The eggs hatch in a few days, the time depending upon the temperature of the water. The larvae transform into adults from late May through July. Illinois Distribution.—This species in Illinois occurs north to Henry and Kan- kakee counties, fig. 27, and it is abundant in both woodland and prairie regions. The ap- parent gaps in range in extreme western Illinois and south-central Illinois, as shown Fig. 27.—Distribution of Ambystoma tex- anum. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SmMItTH: AMPHIBIANS AND REPTILES OF ILLINOIS 37 on the map, are probably merely indicative of little field work in these regions during early spring. The absence of records from Adams County, a relatively well-collected area, is puzzling. Although undocumented by _ specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Jackson County: 3 mi. N Carbondale (Cagle 1942a) ; KNox County: Galesburg (H. Garman 1892). Ambystoma tigrinum tigrinum (Green) Eastern Tiger Salamander Salamandra tigrina Green 1825:116 locality: near Moorestown, N. J.). Amblystoma tigrinum, Cope 1868:183-4. Ambystoma tigrinum, Hurter 1911:75. Ambystoma tigrinum tigrinum, Dunn 1918:457. ?2?Ambystoma lurida, Kennicott 1855:593. 2Amblystoma copianum, H. Garman 1892:215. Ambystoma maculatum nec Shaw, Owens 1941: 183. ?Ambystoma sp., P. W. Smith 1951:192. (type Diagnosis.—A rather large, blue-black or brownish black salamander (largest Illi- nois specimen 330 mm. in total length), fig. 28, with irregularly arranged yellow blotches, which are unequal and variously shaped, on the back and_ sides; costal grooves 12 or 13, sometimes 11 or 14; toes of adpressed limbs usually overlapping by 2 or more costal folds; 2 palmar tubercles distinct on freshly preserved specimens. Variation—In Ambystoma tigrinum tig- rinum, the male differs from the female in having a longer vent and a longer tail. Dur- ing the breeding season, the vent of the male is strongly protuberant. Newly metamorphosed specimens, 50 to 60 mm. from snout to vent, are gray, brown, or olive, often with numerous indistinct dark spots above. Slightly older examples are black above, with a few very small yel- low spots. The pattern of the adult is found in specimens 65 to 75 mm. in snout-vent length. The proportionate length of the legs decreases and the number of teeth in- creases with an increase in size. This vari- ation is summarized in table 6. No well-defined geographic variation within Illinois has been discerned for the eastern tiger salamander, although a dif- ference in size between northern and south- ern specimens is indicated. Fifteen speci- 38 Ittrinors NaturAL History SurveEY BULLETIN Vol. 28, Art. 1 —te oe Fig.28.—An adult Ambystoma tigrinum tigrinum from Randolph County, Illinois. The groundcolor is dark brown or black; the yellow spots are irregular in size and arrangement. In some large adults the spots are obscured. mens now available from the southern third of the state are less than 100 mm. from snout to vent, and numerous other exam- ples observed but not preserved were well under this length. Fifteen specimens out of 49 now at hand from the northern half of Illinois exceed 100 mm. in snout-vent length. Pope (19444) noted that the spe- cies attains its maximum size in the Chi- cago area. The largest specimen known (330 mm. in total length) is from Quincy, Illinois (Langebartel 1946). Lengths and costal groove counts for three samples are — given in table 7. There is considerable individual varia- tion in markings. Several of the large in- dividuals are so dark that the spotted pat- terns are barely discernible. mens, usually smaller individuals, are boldly Other speci- — marbled with black and yellow. Three large Table 6.—Ontogenetic variation in Illinois Ambystoma tigrinum tigrinum. Figures in parentheses are numbers of specimens. CHARACTERISTIC 51-61 (8) 64-73 (9) Total length (mm.)....} 104-117 109-161 Costal folds overlapped by adpressed limbs... 9-21 4214 Vomerine teeth........ 38-55 33-59 Premaxillary-maxillary (Raley Neg Se nO Rarer 82-116 59-114 Snout-VENT LENGTH (mM.) 75-83 (8) | 86-96 (11) | 97-105 (10) 106-115 (7) 139-169 159-208 | 160-228 215-240 5-1 5-1 244-1 24%-0 44-64 48-74 43-83 52-79 102-132 103-148 117-153 110-151 Table 7.—Geographic variation in Illinois Ambystoma tigrinum tigrinum. Figures in — parentheses are numbers of specimens. SOUTHERN HALF or ILiiNots (7 CHARACTERISTIC \/) NorTHern Hatr oF ILLINOIS Eastern (22) WesTERN (18) Range | Mean Snout-vent length | Garnant)peeaeete ney hares eens SOS at ki ce orn Lana Costal grooves......... 11-12 11.7 Range Mean Range Mean Can Ltt Aaa hls te ence eee a 55-115. | 532 eee 12-14 12.6 12-13 12.5 November, 1961 specimens from central Illinois are light olive, with black spots and mottling. Habits.—Like the small-mouthed sala- mander, the tiger salamander is nocturnal and fossorial. Accordingly, it is seldom seen unless it is discovered under a log or rock, or within some steep-sided excava- tion. Although this salamander is not abun- dant, it persists in the most disturbed areas, often occurring within cities and in inten- sively cultivated regions. Its food consists of almost any kind of animal it can over- power. Captive salamanders of this spe- cies take earthworms and hamburger read- ily. The number of individuals found abroad late in the fall suggests that a migration to the breeding ponds occurs at that season. Actual breeding, however, occurs early in the spring. Loose clusters of 25 to 100 eggs Fig. 29.—Distribution of Ambystoma tigrin- um. The nominate subspecies occurs through- out the state. Solid circles indicate localities jrepresented by specimens examined during jthis study; open circles, localities represented Iby published records believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 39 are attached to objects on the bottom of a pond. The incubation period depends on the temperature, probably averaging about 3 weeks. The larvae grow rapidly and in central Illinois transform in July. At meta- morphosis the larvae of this species are about twice the size of other Ambystoma larvae. Illinois Distribution.—This species is state-wide in distribution, fig. 29, but not abundant except in areas with numerous ponds. In most parts of the state, speci- mens are usually found quite incidentally in basements, deep-sided ditches, submerged meter boxes, or similar pits. Many per- manent ponds, either prairie or woodland, harbor the species; small forest-edge ponds are probably preferred. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Cook County: Glenview (Necker 1939c) ; Northfield (Yarrow 18822); Lake Coun- Ty: Waukegan (Necker 1939c); La SALLE County: La Salle (Burt 1935); Mapison County: (Hurter 1893) ; Mason County: SE Havana (Vestal 1913) ; MEN- ARD County: Athens (Dunn 1918) ; Mon- ROE County: (Hurter 1893); Prorta County: (H. Garman 1892). SALAMANDRIDAE This family includes two genera in the United States and Canada; Notophthalmus occurs east of the Great Plains and Taricha on the West Coast. Notophthalmus Rafinesque Three species of this eastern North Amer- ican genus are found in the United States and Canada. The species occurring in Illi- nois consists of several subspecies, but only one of them is found within this state. Notophthalmus viridescens louisianensis ( Wolterstorff) Central Newt Diemyctylus viridescens louisianensis Wolter- storff 1914:383 (type locality: New Orleans, Louisiana). Triturus viridescens louisianensis, Schmidt & Necker 1935 :62. Diemictylus viridescens louisianensis, Brown 1950:24. 40 ILttinois NaturAL History SuRVEY BULLETIN Notophthalmus miniatus, Kennicott 1855:593. Diemyctylus miniatus miniatus, Yarrow 1882a: 161. Diemyctylus viridescens miniatus, Hay 1887a: Diemyctylus miniatus, H. Garman 1890:190. Triton dorsalis nec Harlan, Brendel 1857:254. Diemyctylus miniatus viridescens nec Rafin- esque, Yarrow 1882a:161. Diemyctylus viridescens, Hay 1887b:62. Diemyctylus viridescens viridescens nec Rafin- esque, Cope 1889:212-3. Diemictylus viridescens, Shelford 1913:252. Notophthalmus viridescens viridescens nec Rafinesque, Stejneger & Barbour 1917:8. Triturus viridescens, Dunn 1918:451. Triturus viridescens viridescens nec Rafin- esque, Stejneger & Barbour 1923:4. Diagnosis.—A small, stout, aquatic or terrestrial salamander (largest Illinois spec- imen 104 mm. in total length), fig. 30, with- out costal grooves; gular fold poorly de- veloped; cranial crests present; vomeropal- atine teeth in two longitudinal series; dor- sum yellow-brown, olive-green, or red- brown and sharply cut off from yellow of venter and lower sides; scattered black specks above and below; one or two dorso- lateral rows of small red dots, some of which are not margined with black or at Vol. 28, Art. 1 least not completely encircled. The eft, a peculiar terrestrial stage found only in this salamander, differs from adults, which are aquatic, by the absence of fins on the tail, by the absence of secondary sexual charac- ters, and by the presence of a granular or warty skin and darker groundcolor. Variation.—Efts are difficult to sex, but the depth of the pits in the temporal region (hedonic glands) serves to identify at least some males. Adults in breeding ponds are easily sexed. The male possesses greatly en- larged hind legs with horny material on the inner sides, a swollen cloaca, and conspicu- ous dorsal tail crest during the breeding season, in addition to the deep hedonic pits at all times. The female in the breeding season has dark, converging, cornified ridges on the lips of the cloaca. No data on ontogenetic variation are available for the Illinois populations. Most of the specimens extant are efts. No variation trends within Illinois have been discerned. Ten specimens from north- eastern Illinois vary as follows: snout-vent length 18.8 to 40.2 mm.; total length 39 to 81 mm.; lateral red spots enclosed by black, 0 to 8 per side (average 2.3); lateral head Fig. 30.—Adult Notophthalmus viridescens louisianensis, eft stage, from Monroe County, Illinois. The groundcolor above is dark brown or olive-brown; below, yellow. het ea ce Tat ae, Sache a al he ES Ls 2 November, 1961 stripe prominent in four specimens, weak in five, absent in one. Fourteen specimens from the southern third of the state exhibit the following variation: snout-vent length 18.2 to 45.2 mm.; total length 35 to 104 mm.; lateral red spots ringed with black, 0 to 9 (average 4.4); lateral head stripe prominent in | specimen, weak in 13. Habits.—Notophthalmus viridescens has a rather complicated life history, as adults have both a terrestrial and an aquatic stage. Presumably the subspecies Jouisian- ensis and viridescens have essentially the same life cycle, which in N. wv. viridescens includes an underwater nuptial dance and deposition of spermatophores and eggs in winter or early spring. The eggs, which are attached individually to submerged vegeta- tion, hatch in 2 or 3 weeks, and the larvae transform usually in 2 or 3 months. The transformed newt is rather dry and warty- skinned. It soon loses its gills and fins; it is then called an eft. Because the eft lives under bark, logs, or rocks in typical sala- mander habitats, this is the form most often encountered in Illinois. After 2 or 3 years, the eft is sexually mature and ready for an aquatic existence. It develops fins and skin changes that permit aquatic respiration. The number of tiny efts that have been found in southern Illinois suggests that the initial aquatic stage may be shorter in lowisianensis than the 2 or 3 months of viridescens. Newts eat a variety of invertebrates, mollusks be- ing a particularly important item. Illinois Distribution—The central newt : probably once occurred throughout the state except in the extreme western part. All recent records are for either the northern or for the southern fifth of Illinois, fig. 31. Although records for the central part of the state are at least 35 years old, there is little reason to doubt them, inasmuch as the central newt is easily recognized. It is likely that its occurrence in the area be- tween extreme northern and southern IIli- -nois was sporadic even before cultivation. The destruction of much of the forest, the draining of ponds and marshes, and the | lowering of the water table probably accel- erated the disappearance of this salamander | from central Illinois. Although undocumented by specimens. published records for the following localities }are believed valid; most are indicated on the distribution map by hollow symbols: Cores : SmM1TH: AMPHIBIANS AND REPTILES OF ILLINOIS 4] \ Fig. 31.—Distribution of Notophthalmus viridescens. Hatching indicates the presumed range of the subspecies /owisianensis in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published rec- ords believed to be valid. The lower map depicts the total range of the species in the United States. County: Charleston (Hankinson 1917) ; Harpin County: Cave in Rock (H. Gar- man 1892); Jackson County: Grand Tower (H. Garman 1892); KANE Coun- TY: Geneva (H. Garman 1892); McLEAn County: Normal (Dunn 1918); Prorta County: Peoria (H. Garman 1892); Sr. Crair County: Bluff Lake (Hurter 1893) ; TAZEWELL County: Delavan (H. Gar- man 1892); Union County: Anna (Cagle 1942a). PLETHODONTIDAE Four of the 17 plethodontid genera known from the United States and Canada are represented in Illinois. The family is pri- marily New World in distribution but it is represented in Europe by one genus. 42 Ittrnors NaruraAL History SurveEY BULLETIN Eurycea Rafinesque The genus Eurycea includes eight species, most of which have several subspecies. Three species occur within Illinois. Eurycea bislineata rivicola Mittleman Midwest Two-Lined Salamander Eurycea bislineata rivicola Mittleman 1949: 89-96 (type locality: Echo Canyon, McCor- mick’s Creek State Park, Owen County, Indiana). Eurycea bislineata bislineata nec Green, Dunn 1926 :307. Eurycea bislineata, Jordan 1929:218. Spelerpes bilineatus, Davis & Rice 1883a:27. 2Desmognathus fusca nec Rafinesque, Hank- inson 1915:293. 2Eurycea longicauda nec Green, Peters 1942: 182. Diagnosis.—A small, slender, yellow or tan salamander (largest Illinois specimen 108 mm. in total length), fig. 32, with a lat- eral brown or black band of variable width Vol. 28, Art. 1 extending from the eyes almost to the tail tip; 13 to 15 costal grooves; 114 to 5 costal folds between the adpressed limbs; 6 to 22 vomerine teeth in two arched series behind and between the choanae; and usually either a median series of dark spots or irregularly spaced dark middorsal flecks. Variation.—According to Bishop (1941), the male of this salamander differs from the female in its larger size, wider head, larger premaxillary teeth, and nasolabial tubercles. The teeth of the female at all times, and of the male from June to September, are said to be bicuspid. Ontogenetic variation is not marked in the Illinois specimens available. The differ- ence in ratio of tail length to total length, noted by Oliver & Bailey (1939) and Mit- tleman (1949), is apparent only when the figures are averaged. In 12 specimens 53 to 75 mm. in total length, the tail length ranges from 51.5 to 57.4 per cent (average 55.1) of the total length. In 12 specimens 85 to 108 mm. in total length, the tail length ranges Fig. 32.—Adult Eurycea bislineata rivicola from Clark County, Illinois. The groundcolor is tan or yellow; the markings are dark brown. November, 1961 SMITH: AMPHIBIANS AND RepTILES OF ILLINOIS 43 Table 8.—Geographic variation in Illinois Eurycea bislineata rivicola. Figures in paren- theses are numbers of specimens. PULASKI Popre-GALLATIN CLARK-EDGAR VERMILION County (12) Counties (16) Counties (31) County (12) CHARACTERISTIC Range | Mean | Range | Mean | Range | Mean | Range | Mean Snout-vent length (mm.) | 24-43 |........ PR al eta DSA Se als Bees SOAS) Nive eee Total length (mm.)..... 8-99 Ma leeaeers. Se ag] ena ct SOSMOS Wa era auc GD Saar MIEIICELE CEM Ro cite lt carn ac ee le aocke aie 9-21 IBe5) 6-22 G5) 10-30 13.4 Costal folds between adpressed limbs....... ts 2.0 244% | 2.9 14%-5 352 1144-3 2.4 Per CENT OF Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS (ostal grooves 15....... 0 12 + 0 Costal grooves 14....... 67 44 48 75 Costal grooves 13....... 33 44 48 25 Stripes extending more than one-half tail eselentiieceeles orto she sis vs 3. 100 100 85 75 Unmarked dorsum...... 16 6 16 25 from 53.6 to 61.0 per cent (average 57.0) of the total length. The most apparent geographic variation = Illinois specimens is in color and pattern. The 16 specimens from Pope and Gallatin counties are the most strikingly marked, most of them having distinct spots middorsally on a clear yellow background. Viewed from the side they are sharply bi- colored, and the light spots in the lateral ‘dark stripes are conspicuous. Forty-seven /specimens from east-central Illinois are less /prominently marked, the middorsal flecks | being less discrete and the groundcolor more often tan or dirty yellow. Variation in ad- ditional characters for four samples is shown in table 8. Habits.—The two-lined salamander may be abundant in small, rocky streams and in springs and seeps in mesic forest. In the latter habitat specimens are found by raking wet leaves along stream banks or by digging in wet shale banks bordering brooks. This salamander is slippery, surprisingly agile, and difficult to hold. Captive individuals run with considerable speed and are able to jump some distance. If placed in a ter- rarium, they quickly climb the glass sides, their moist bodies providing sufficient ad- hesion for them to stick to the glass sur- ‘face. Arthropods and small worms are their chief food items. During the month of May, the compara- tively large eggs of this salamander may be found under flat rocks, submerged branches, or leaves. They are closely packed in a sin- gle layer of 12 to 30 per clump. Hatching occurs in approximately a month, and the larval period requires something more than a year. Ulinois Distribution——This typically eastern salamander is apparently confined in Illinois to the Indiana-Illinois border and eastern portion of the Shawnee Hills, fig. 33. The distribution pattern suggests that even small prairies or areas of farmlands may be barriers, and the woodlands of the Southern Division are probably unsuitable because of aridity in summer and fall. The apparent absence of the species from the western counties of the Shawnee Hills is dificult to explain, inasmuch as the area contains mumerous. rocky streams and springs. Mittleman (1949) plotted a record for the Starved Rock area but did not cite the locality in his list of material. La Salle County is west of our records, but it has seemingly good habitat for the species. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: CoLEs County: Charleston (Hankinson 1915). Fig. 33.—Distribution of Eurycea bislineata. Hatching indicates the presumed range of the subspecies rivicola in Illinois; solid circles indicate localities represented by specimens examined during this study; the open circle indicates a locality represented by a _pub- lished record believed to be valid. The lower map depicts the total range of the species in the United States. Eurycea longicauda (Green) Four subspecies of this eastern, stream- inhabiting salamander have been described, but only three are recognized in the present study. Two well-marked subspecies occur within Illinois. Eurycea longicauda longicauda (Green) Long-Tailed Salamander Salamandra longicauda Green 1818:351 (type locality: New Jersey; revised to vicinity of Princeton by Schmidt 1953). Eurycea longicauda, Stejneger & Barbour 1917: £9: Eurycea longicauda longicauda, Cagle 1941:5. Spelerpes longicaudus, Davis & Rice 1883a:27. Eurycea longicauda pernix Mittleman 1942: 101-5, pl. 20 (along Jimmie Strahl Creek, Ittrinois NaturRAL History SURVEY BULLETIN = Vol. 28, Art. 1 2\%4 mi. SE Nashville, Brown County State Park, Indiana). Diagnosis.—A moderate-sized, slender, long-tailed salamander (largest Illinois spec-— imen 153 mm. in total length), fig. 34, with yellow or orange-yellow groundcolor and_ brown or black maculations that tend to coalesce on the sides to form lateral bands sides of tail with vertical dark bars; 13 to 14 costal grooves; toes of adpressed limbs overlapping by 2 costal folds or cena ee by 2 folds; 12 to 39 vomerine teeth in all; venter immaculate yellow; middorsum plaid or more often with numerous dark spots” clustered along the midline. Remarks.—The recently described Bury cea longicauda pernix (Mittleman 1942) of unglaciated Indiana is said to differ from is l. longicauda by a higher vomerine tooth count, more intense pattern, and greater de- velopment of sexual dimorphism. The holo- type and allotype of pernix have, respec- tively, 27 and 32 vomerine teeth. Only 8.6 per cent of the Illinois specimens, exclusive of E. 1. melanopleura intergrades, have 27 or more vomerine teeth. Tooth counts for 11 specimens, which should be referable to pernix on the basis of range (Brown, Jen- nings, Morgan, and Owen counties, Indi- ana), vary from 11 to 26 (average 19.6); similar counts for 6 specimens of E. J. longi- cauda from glaciated Indiana (Parke and Montgomery counties, Indiana) vary from 18 to 28 (average 22.2). Accordingly, a high number of vomerine teeth does not ap- pear to be diagnostic for the population im unglaciated Indiana and Illinois. I can discern no differences in development! of secondary sexual characters or patter which will separate specimens of E. longi- cauda from glaciated Indiana from those of unglaciated areas. There is a ia for the lower sides of specimens from Mary- land and Pennsylvania to have zones of small, well-separated spots, whereas the lower sides of salamanders from the con a ee Smoky Mountains and transmontane region are_vermiculate. It seems best to refer the Illinois populations to E. 1. longicauda, pend- ing a restudy of the species. Variation.—External sexual differences in this salamander are slight. Bishop (1943) reported that the male has more swollen nasolabial tubercles than the female, slightly papillose vent, a shorter tail, and toes almost meeting when the limbs ar November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 45 Fig. 34.—Adult Eurycea longicauda longicauda X melanopleura intergrades from Monroe County, Illinois. The specimen at the left is fairly typical of the nominate subspecies; the speci- men at the right shows some melanopleura influence in the coalescence of the dark bars on the sides of the tail and the spotting on the dorsum. The groundcolor ranges from lemon yellow to almost orange; the markings are dark brown or black. adpressed. In the female the toes of the ad- pressed limbs are separated by at least 1 costal fold. Subadults are quite different from adults in general appearance, possessing a clear yellow groundcolor, smaller middorsal spots, shorter tails, and fewer vomerine teeth. They usually have prominent dark spots on the anterior part of the chins, whereas adults usually have dusky chins. The onto- genetic variation in proportionate tail length and number of vomerine teeth is summa- rized in table 9. Geographic variation for this subspecies in Illinois is manifested by intergradation with the western race, FE. 1. melanopleura. Populations of typical /ongicauda occur in the Wabash Border counties and through- out the Shawnee Hills. A slight influence of melanopleura is seen in the tendency for the vertical tail bars to coalesce in occasional specimens from western Union and Jackson counties. Samples from other Lower Mis- sissippi Border counties exhibit a gradual replacement, south to north, of longicauda characters by those of melanopleura. The Table 9—Ontogenetic variation in proportionate tail length and in vomerine tooth counts in Illinois Eurycea longicauda. Figures in parentheses are numbers of specimens. CHARACTERISTIC Torat LENGTH (MM.) 54-84 (7) 133-155 (7) Mean Range Mean Range Tail length as percentage of total length.......... Combined vomerine tooth counts................ ac) 60.8-64.7 51.9-61.0 5 I 20-31 63.0 13-26 24.2. 46 Ittinors NATURAL History SurvEY BULLETIN longicauda influence predominates as far north as St. Louis, but north of St. Louis specimens possess characters closer to those of melanopleura. A single specimen (INHS), a juvenile, is known from the Wabash Border Division. This juvenile, 54 mm. in total length, has 14 costal grooves, a combined - vomerine count of 16, 1 costal fold between toes of the adpressed limbs, a distinctly barred tail, Vol. 28, Art. 1 or outcrops by searching these areas with a flashlight. On rainy days, individuals are sometimes abroad and may be seen on trunks of trees. Normally, however, they remain hidden under rocks or logs or within crev- ices in bluffs during the day. Their food consists predominantly of arthropods. Details of the life history of this subspe- cies are lacking, but they are probably sim- ilar to those of E. bislineata rivicola. Larvae Table. 10—Geographic variation in Illinois Eurycea longicauda. Figures in parentheses | are numbers of specimens. Grae UNIon AND Monroe AND PIKE AND Hrus (23) Jackson RANDOLPH GREENE CHARACTERISTIC son ee Counties (13) Counties (20) Counties (18) Range | Mean Range | Mean | Range | Mean | Range | Mean Snout-vent length OS ee ner 26,855.46. > «2. 3S oi 2-85 50/590 a1 27.0255. 5). vate 33.8-48.0]........ Vomerine teeth..... 13-31 20 12-39 22 12-30 21 12-24 18 Per CENT OF Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS Costal grooves 13... 100 100 90 7 Costal grooves 14... 0 0 10 93 Tail bars present... 100 100 85 22 Middorsum plain or with median row wh Shots: 2s iri 100 77 50 6 Middorsum with many scattered SPOS: seis ok 0 23 50 94 Venter plain........ 100 69 65 39 35 61 Venter flecked...... | 0 | and an unmarked middorsum. Geographic variation for a sample of E. 1. longicauda from the Shawnee Hills and three samples of E. 1. longicauda X melanopleura inter- grades from the Upper and Lower Missis- sippi Border divisions is summarized in table 10. Habits.—The long-tailed salamander oc- curs in abundance along rocky, swift streams in dissected, forested regions. It seems to be present in all of the areas in which this habi- tat occurs in the southern half of Illinois. E. longicauda does not occur in woodland seeps and springs without rock outcrops as does E. bislineata. Except for a more re- stricted habitat, Jongicauda is similar in hab- its and occurrence to bislineata. The species is nocturnal and can be found on boulders of various sizes may be found throughout the winter months, indicating that the larval period probably requires 2 years. Trans- forming larvae can be found throughout the warm months in southern Illinois. Illinois Distribution—This salamander is a characteristic species of the Shawnee Hills division and it occurs sporadically in the Wabash Border, fig. 36. Apparently it is limited to wooded regions with relatively large areas of rock outcrop. The distribu- tion is continuous up the river bluffs in the Lower Mississippi Border. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: St. CLAIR County: Bluff Lake (Hurter 1893). November, 1961 Eurycea longicauda melanopleura (Cope) Dark-Sided Salamander Spelerpes melanopleurus Cope 1893b:383 (type locality: Raley’s Creek, White River, Mis- souri). Eurycea longicauda pernix X E. 1. pleura, Mittleman 1942:104. Eurycea longicauda melanopleura, Grimmer & Langebartel 1948 :224. melano- Diagnosis.—A medium-sized, long-tailed salamander (largest Illinois specimen 130 mm. in total length), fig. 35, related to the subspecies /ongicauda but differing in having a longitudinal dark band (rather than a se- ries of vertical bars) on each side of the tail, numerous middorsal dark spots scat- tered or arranged in several irregular rows, numerous dark flecks on venter, yellow- SmMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 47 green to yellow-brown groundcolor, and larger eyes. Variation.—The males of the dark-sided salamander differ externally from the fe- males in having more swollen snouts and larger nasolabial protuberances, but so many intermediate examples occur that dissection is often the only method by which the sex of an individual can be accurately deter- mined. In this subspecies subadults differ from older specimens less markedly than in Eury- cea longicauda longicauda but in similar characters. Seven specimens, 88 to 114 mm. in total length, have tail lengths 48.0 to 65.5 (average 58.3) per cent of the total length, and six specimens, 115 to 130 mm. in total length, have tail lengths 58.5 to 65.2 (av- erage 60.8) per cent. The groundcolor is us- ually more yellowish in small individuals, Fig. 35.—An adult Eurycea longicauda melanopleura from Adams County, Illinois. The groundcolor ranges from greenish yellow to pure yellow; the markings are black or dark brown. 48 Intinors NaruraAt History SurvEY BULLETIN but the pattern is essentially the same. Some large specimens are suffused with fine flecks of darker pigment. The Illinois population differs slightly from samples from more western localities in the smaller average number of vomerine teeth, in the poorly developed cirri, and in the usual irregularity of the rows of mid- dorsal dark spots. Nevertheless, the sam- ples from western Illinois are homogeneous, quite distinct from the eastern E. 1. longi- cauda, and the differences noted are not due to intergradation with the eastern form. Thirteen specimens from Adams County show the following variation: snout-vent length 32.8 to 54.0 mm.; total length 88 to 133 mm.; 13 costal grooves in 3 speci- Fig. 36.—Distribution of Eurycea longicauda. Vertical hatching indicates the presumed range of E. 1. longicauda; horizontal hatching, the presumed range of E. 1. melanopleura; cross- hatching, the area of intergradation between the two subspecies; solid circles indicate local- ities represented by specimens examined dur- ing this study; open circles, localities repre- sented by published records believed to be valid. The lower map shows the total range of the species in the United States. Vol. 28, Art. 1 mens, 14 in 10; toes of adpressed limbs overlapping by | costal fold to a separation of 2 folds; combined vomerine tooth counts 14 to 30 (average 20.5); cirri present in 1 specimen, nasolabial tubercles in 12; scat- tered ventral flecks in 11 specimens, immac- ulate venters in 2. Intergrades of melanopleura X longicauda have been discussed under the subspecies longicauda. Samples from Pike and Greene counties display some characters of longi- — cauda but the melanopleura influence is so pronounced that these specimens would key out as melanopleura. Habits.—This subspecies is similar to the eastern long-tailed salamander in habits. — The only difference that seems worthy of notice is the more frequent occurrence of melanopleura within caves. Illinois Distribution.—This salamander is common in rocky streams, caves, and springs of the Mississippi River bluffs and — dissected wooded uplands in Adams and Pike counties, fig. 36. Intergrading popula- tions occur south to Union County, but only ~ those populations north of St. Louis have — the general appearance of melanopleura. a The apparent absence of this subspecies — north of Adams County may be due to tem- perature intolerance, inasmuch as appar- ently suitable habitat extends well north of the known distribution. The upper Illinois 4 River valley appears to afford suitable habi- — tat, but none of the subspecies of E. longi- cauda has been able to ascend this valley, probably because the lower portion lacks — the requisite rocky streams. ; Although undocumented by specimens, a published record for the following locality — is believed valid and is indicated on the dis- — tribution map by a hollow symbol: ADAMS — County: 11 mi. S Quincy (Grimmer &~ Langebartel 1948). Eurycea lucifuga Rafinesque Cave Salamander Eurycea lucifuga Rafinesque 1822:3 (type — locality: caves near Lexington, Kentucky) ; Stejneger & Barbour 1917:19. 2Spelerpes ruber nec Latreille, Hay 1887a:5. Spelerpes ruber ruber nec Latreille, Yarrow 18824a:157. Spelerpes maculicaudus, Hurter 1911:86. Diagnosis.—A medium-sized, slender, red or red-orange salamander (largest Illinois” November, 1961 SMITH: AMPHIBIANS AND ReEprTILEs OF ILLINOIS 49 Fig.37.—An adult Eurycea lucifuga from Union County, Illinois. The groundcolor is bright red-orange; the markings are jet black. specimen 159 mm. in total length), fig. 37, with numerous black spots scattered irregu- larly over the back and sides; 13 to 14 costal grooves; toes of adpressed limbs sep- arated by 11% costal folds to an overlap of 2 folds; vomerine teeth usually in two J- or C-shaped series, the combined count rang- ‘ing from 17 to 39. _ Variation.—Males of this species can be distinguished from females by their more prominent nasolabial swellings, the pres- ence of mental glands, the distinctly mar- gined vents, and the slightly longer legs (an average of 1.08 costal folds between toes of adpressed limbs in 12 males and 0.47 costal fold in 18 females). Newly transformed specimens are simi- i in general appearance to young Eurycea longicauda. ‘The sides are dark gray, en- closing many light flecks, and the middorsal areas are yellow-gray, with scattered dark flecks. Slightly older specimens are yellow, with small black spots scattered over the backs and sides, differing from adults chiefly in the yellow ground color and the less con- ‘spicuous dorsal spots. Subadults differ in jnumber of teeth and relative tail length. ‘Seven subadults, 65 to 102 mm. in total length, vary in vomerine tooth counts from 118 to 28 (average 20.1) and the tail makes , up 52.9 to 58.3 (average 55.0) per cent of the total length. Ten large specimens, 128 to 159 mm. in total length, have 20 to 39 vomerine teeth (average 26.2), and the tail ranges from 55.1 to 60.4 (average 58.1) per cent of the total length. Several trends in variation are apparent in the Illinois series. Southeastern Illinois specimens are usually more heavily spotted above, are shorter-legged, have fewer vom- erine teeth, and have less prominent second- ary sexual characters than salamanders from the Lower Mississippi Border coun- ties. These trends in three samples are sum- marized in table 11. Data for single speci- mens from localities geographically inter- mediate have not been included in the table. Habits.—In Illinois, the cave salamander is not restricted to caves. In fact, the two localities where the species is most abun- dant are cypress swamps, one near Forman in Johnson County and one at Pine Hills in Union County. Both of these areas are bordered by rock bluffs, however, and both contain swamps that are spring fed. Adults and transforming larvae are common under logs and leaves within the swamp well away from the rock outcrops. Cave salamanders are nocturnal, spending the day concealed under objects along stream margins, in 50 Ittrnois NaATuRAL History Survey BULLETIN Vol. 28, Art. 1 Table 11—Geographic variation in Illinois Eurycea lucifuga. Figures in parentheses are numbers of specimens. CHARACTERISTIC Snout-vent length (mm.).. Total length (mm.)....... Vomerine teeth.......... Toes of adpressed limbs... Costal grooves 13........ Costal grooves 14........ Males with cirri. ........ ExTREME SOUTHEASTERN ILurinors (17) Union County (15) Range Mean Range | Mean Sy Ooh Aer Saal pie Saree ee 3757 a ole a eee C5158 ste T9A4 SIS ee 17-33 22.6 18-32 24.4 —14-—-+14 |........ —$ = +2 Ol ashes Per CENT OF Per CENT OF SPECIMENS SPECIMENS 6 0 76 80 18 20 0 26.6 Monroe County (7) Mean Per CENT OF SPECIMENS Fig. 38.—Distribution of Lurycea lucifuga. The hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study. The lower map depicts the total range of the species in the United States. crevices in the rock outcrops, or in caves. At night a number of cave salamanders may be found on a single large boulder. They are quick and surprisingly difficult to pick up because of their slipperiness and alertness. E. lucifuga feeds chiefly upon arthropods. Little is known of the life history of this salamander. Females with well-developed eggs have been taken in spring and in fall. The larvae, which are similar to other Eurycea larvae, overwinter one or more sea- sons. They transform throughout the warm months. Illinois Distribution.—This species oc- curs in caves and springs throughout the Shawnee Hills division and in the Lower Mississippi Border counties north to at least Monroe County, fig. 38. Hemidactylium Tschudi The monotypic species of this predom- inantly northern genus is known only in ex- treme northeastern Illinois. Hemidactylium scutatum (Schlegel) Four-Toed Salamander Salamandra scutata Schlegel 1838:119 (type locality: Nashville, Tennessee). Hemidactylum scutatum, Gebhard 1854:25. — Hemidactylium scutatum, Kennicott 1855: 593. Diagnosis.—A small, slender plethodon- tid salamander (largest Illinois specimen 95.5 mm. in total length), fig. 39; 4 toes on November, 1961 Fig.39.—An adult Hemidactylium scutatum from Ste. Genevieve County, Missouri. groundcolor above is yellowish brown or reddish brown, below enamel white spotted with black. SYR each hind foot; tail with a basal constric- tion; a distinct median impressed line from base of tail to top of head, where it bifur- cates; 12 to 14 costal grooves; groundcolor below white, with numerous black blotches. Variation.—Bishop (1941) reported that males of this salamander are smaller and more slender and have slightly longer tails, more reddish brown above, and more prom- inently truncate snouts than females. Blanchard & Blanchard (1931) have ade- quately described ontogenetic variation in this species and have prepared graphs to de- termine age groups. Young of the year are said to average 30 mm. long in females and 33 mm. in males by October. These juve- niles differ from adults in the absence of basal tail constrictions and in their propor- tionately shorter tails. At the end of the second season, males average 50.6 mm. long and females 55.1 mm. The constriction at the base of the tail is then evident, and the tail is longer than the snout-vent length of the animal. In the small series of Illinois specimens at hand, individuals range from 29.2 to 40.5 mm. in snout-vent length and 71.0 to 95.5 mm. in total length. Costal groove counts are 13 in seven specimens, 12 in four. Costal folds between the adpressed limbs range from 214 to 514. The dorsum is plain red-brown or yellow-brown, with indistinct darker spots. The venter varies from plain white to well spotted, with evenly distrib- SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 51 ae: a Be 2 y | ( E { os) i [ | >| t Fa 4 Y ise brake © f Ld k = = 0) ate agen Seale ( { Fig. 40.—Distribution of Hemidactylium scu- tatum. Hatching indicates the presumed range of the species in IIlinois; solid circles indicate localities represented by specimens examined during this study. The lower map depicts the total range of the species in the United States as currently known. mn bo uted blotches. Most specimens are interme- diate in ventral pattern, possessing black spots lateroventrally. Habits.—The four-toed salamander is extremely rare in Illinois, and all the avail- able specimens are quite old. The species is reportedly a bog animal, occurring under logs, bark, or sphagnum. Its food presum- ably consists of minute arthropods. According to Bishop (1943) breeding oc- curs in late summer and fall, but oviposi- tion does not take place until spring. Ap- proximately 30 eggs in a cluster are laid near water in sphagnum or among roots of vegetation. The female remains with the eggs for the | to 2 months required for hatching. Metamorphosis occurs about 6 weeks after hatching. Illinois Distribution—The four-toed salamander is thus far known only in Lake and Cook counties, fig. 40, but may also occur in northwestern Illinois. Plethodon Tschudi This genus includes 15 species, most of which consist of two or more subspecies. Three species occur within Illinois. Plethodon cinereus cinereus (Green) Red-Backed Salamander Salamandra cinerea Green 1818:356 (type locality: New Jersey; revised to vicinity of Princeton by Schmidt 1953). I_tinors NaruraAL History SurveEY BULLETIN Vol. 28, Art. 1 Plethodon erythronotus cinerea, H. Garman 1892:566-7. Plethodon cinereus cinereus, 1883a:26-7. Plethodon cinereus, Shelford 1913:197, 243, 244, 256. Plethodon 1882a:154. Plethodon erythronotus erythronota, H. Gar- man 1892:366-7. Davis & Rice cinereus erythronotus, Yarrow Diagnosis.—A small, slender salamander (largest Illinois specimen 109 mm. in total length), fig. 41, with two color phases; lead-backed phase uniformly black or brown above; red-backed phase dark, with a mid- dorsal, straight-edged red band extending from the occiput well onto the tail; limbs small and weak, the toes of the adpressed limbs separated by 4 to 9 costal folds, usu- ally more than 6; costal grooves usually 18 or 19, sometimes 17 or 20; tail of adult slightly longer than snout-vent length; sec- ondary sexual characters poorly developed; ventral interhumeral area (in life) without orange suffusion. Variation.—Specimens of the red-backed salamander are difficult to sex accurately by external characters, although females tend to be slightly larger and to have more vo- merine teeth than males. The males, when they are sexually active, have nasolabial swellings and each has a shelf on the tip of the lower jaw. Juveniles differ from adults in having rel- atively shorter tails, relatively larger heads Fig. 41.—Adult Plethodon cinereus cinereus from Clark County, Illinois. The specimen at the left is the dark, unicolor phase; the specimen at the right, a red-backed example. November, 1961 Table 12.—Geographic variation in Illinois Plethodon cinereus. are numbers of specimens. SmMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 53 Figures in parentheses VERMILION CLARK CRAWFORD County (18) County (18) County (27) CHARACTERISTIC | Range Mean Range Mean Range Mean Snout-vent length (mm.).........| 25-47 | Se Be, sess ery Mea bd Stee Pe O82 STA WA fetes ote Tail length as percentage of total \SEGLOs Sogo eee eee eee 45.2-55.1 519 45.0-55.0 Sale 44.0-54.8 50.0 Beal PTOOVES............00205: 18-20 | 19.1 17-19 18.6 18-20 1 PS) Separation of toes of adpressed [STIDS: 26 age eee eee eee 620-950 leer hee 5.5—9.0 Wall 7.5-10.0 8.4 Momerine teeth................- 7-15 10.7 9-18 13.0 9-16 12.4 and limbs, and lower average numbers of vomerine teeth. Bishop (1941) noted that the red middorsal stripe continues to the tip of the tail in a juvenile, whereas it ter- minates somewhere in the distal third of the tail in an adult. The red-backed and lead-backed phases of this salamander occur together in all locali- ties where the species is known in the state. The red-backed phase predominates in IIli- nois collections, averaging 66 per cent, ex- cept in a sample from Crawford County, where only 2 per cent are red-backed and the remainder are dark. This sample has a somewhat higher average costal groove count than other samples and a greater average number of folds between toes of the adpressed limbs. It possesses an extraor- dinary range of variation in ventral pig- mentation, some specimens having a_ uni- form blue-black venter, others having the stippling more or less typical of Plethodon cinereus cinereus, and still others having a dark venter with coarse patches of white pigment. Although the Crawford County sample is aberrant in these respects and shows some approach to P. richmondi of the Appalachian Plateaus region, its char- acters widely overlap those of P. c. cinereus, to which it is here assigned. The geographic variation illustrated by the Crawford County sample and two other collections of P. cinereus is summarized in table 12. A population of red-backed salamanders | occurring on the Mississippi River bluffs from Jackson to Alexander counties has | been referred to P. cinereus by various au- | thors, but a recent study of the relation- ships of this population reveals that, al- though it shares with cinereus a straight- edged middorsal stripe, other characters in- dicate that it should be referred to P. dor- salis. It is accordingly discussed in more detail under that species. Habits.—In the early spring, the small, slender red-backed salamanders are most frequently encountered under logs and rocks or within moist rotten stumps on hillsides. Later in the season, as the ground dries out, these salamanders retreat into the ground or move down the hillsides, where there is more moisture. When first uncovered they remain motionless, but when prodded they rush away to cover, each with looping movements of the tail and body. Captive specimens climb vertical surfaces with ease, as the moist body adheres firmly to almost any smooth surface. The food of the red- backed salamander consists of minute arth- ropods, annelids, and mollusks. Collembola are probably important dietary items. Of this salamander, Bishop (1941) re- cords that, in New York, spermatophores are deposited on leaves and sticks in late fall. The females receive the sperm pack- ets, and after fertilization the eggs are laid in crevices, usually in rotten logs or under bark. Occasionally several females may be found within one rotten log, each guarding her suspended cluster of approximately half a dozen eggs. Hatching occurs in late sum- mer. Each newly hatched larva is attached to the yolk of the egg for a period of a day or so, after which the gills disappear; the hatchling is a terrestrial salamander. The aquatic stage, characteristic of most am- phibians, has been lost in species of Pletho- don, and most of the brief larval period is spent within the egg. 54 a I rae ‘ a cs Fig. 42.—Distribution of Plethodon cinereus. Hatching indicates the presumed range of the subspecies cimereus in Illinois; solid circles indicate localities represented by specimens examined during this study. The lower map depicts the total range of the species in the United States. Illinois Distribution—The red-backed salamander is known in Illinois only from the extreme eastern part, fig. 42. In north- eastern I]linois, it is inexplicably rare or per- haps extinct. It abounds in adjacent Indiana and in nearby Michigan. Although undocumented by _ specimens, published records for the following locali- ties are believed valid: Cook County: West Northfield (Yarrow 1882a); VERMILION County: Lake Vermilion (Peters 1946). (Records not plotted because of proximity to records based on museum specimens. ) Plethodon dorsalis Cope Zigzag Salamander Plethodon cinereus dorsalis Cope 1889:138 (type locality: Louisville, Kentucky) ; Bishop 1943 :236. Plethodon dorsalis, Stejneger & Barbour 1917: 15. Ittino1s NATURAL History SuRVEY BULLETIN Vol. 28, Art. 1 Plethodon cinereus nec Green, Cagle 1942a: 176. Diagnosis.—A small, slender, red-backed or uniformly dark salamander (largest IIli- nois specimen 114 mm. in total length), fig. 43, allied to Plethodon cinereus, but differ- ing over most of its range in having a strongly lobulated (zigzag rather than straight-edged) red or yellow middorsal band, or a straight-edged middorsal stripe with the following combination of charac- ters: 16 to 18 costal grooves; 3.5 to 7.5 costal folds between toe tips of adpressed limbs; tail length of adult usually less than snout-vent length; shoulder and _ interhu- meral region pigmented with orange or red (in life) ; mental gland prominent in male; and a stouter body, the statement in Bishop (1943) that P. cinereus is less slender than dorsalis notwithstanding. Variation.—Bishop (1943) noted that well-marked sexual dimorphism is lacking in this species. The specimens in our series, on the contrary, display marked sexual char- acters, the male differing from the female in having a conspicuous mental gland, naso- labial swellings, and a pair of free lips at ine Bese the posterior end of the vent. The vent of — the female is a simple slit. Ontogenetic variation in this species is similar to that found in P. cinereus. The number of vomerine teeth shows less corre- ~ lation with body size, but the number of — costal folds between toes of the adpressed eee limbs and the body size are more directly — correlated. ; Rather marked geographic variation is exhibited by this species in Illinois. A population in the extreme southwestern part — of the state (the Mississippi River bluffs of Alexander, Union, and Jackson counties) is atypical, inasmuch as it consists entirely of the red-backed phase and consists almost invariably of salamanders with straight- edged middorsal stripes. These salaman- ders, because of their pattern features, bear a remarkable superficial resemblance to the allied P. cinereus. A population in southeast- — ern Illinois is typical P. dorsalis in struc- tural and pattern features, most obviously in the zigzag stripe of the red-backed phase. The salient features of variation exhibited — by a sample of typical dorsalis and by a sam-_ ple of the Mississippi River bluffs sala- | manders are summarized in table 13. Plecat Ane eNotes Fas en Eee 2 os ieckaks 5, a es oe | November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 55 Two specimens from Vermilion County Individual variation among specimens of ' and a small series from a locality between the typical population is manifested pri- Anna and Jonesboro, Union County, appear marily in the representation of the two color to be typical dorsalis. phases and by the distinctness of the mid- Fig. 43.—An adult Plethodon dorsalis from Pope County, Illinois. The groundcolor is dark brown or black; the middorsal stripe, when present at all, is red or yellow. Table 13.—Variation in two samples of Illinois Plethodon dorsalis. Figures in parentheses ' are numbers of specimens. | | SOUTHEASTERN | ) | EXTREME MIssIssIPP1 - Tumors (65) River Buurrs (49) HARACTERISTIC Range Mean Range Mean _| Stripe width as percentage of body width.............. 23-44 32.0 23-41 32.0 REE SLOOV CSET SP ey Pas Acie i ysGareee sans oeie sine Sees 16-19 17.4 16-18 17.0 Memoids between adpressed limbs.................-+---- 3.5—8.0 Ie} 2.0-7.0 5.4 §) Tail length as percentage of total length............... 42.5-51.5 | 46.8 | 42.5-51.5 | 47.6 Per CENT OF Per CENT OF i) SPECIMENS SPECIMENS SSS et Cp A i I ae, se 69 96 Smeed-backed with zigzag stripe.............0:++-00006: 98 15 56 Ittrnoris Narurat History SurvEY BULLETIN dorsal stripe. Unlike P. cinereus, this species includes occasional specimens intermediate between the two color phases, and the zigzag stripe can be discerned in some interme- diates only by careful examination. Among specimens with the red or yellow stripe, the lobulations extend posteriorly for the entire body length in approximately one-third of the material at hand, but for at least half of the body length in the majority of the specimens. A specimen from Hardin Coun- ty is anomalous, with the middorsal band straight-edged on one side and strongly an- gulated on the other. Habits.—In the early spring, zigzag sal- amanders are extremely abundant under flat rocks on wooded hillsides. In habits they are similar to red-backed salamanders but they are perhaps more rigidly restricted to a rock habitat. During the summer and fall they are rarely found; presumably they retreat into caves or rock crevices. The life history of P. dorsalis is probably similar to that of the related P. cinereus, although dorsalis probably lays its eggs in crevices of rock outcrops rather than in logs. Illinois Distribution.—This species has been confused with P. cinereus because of the difficulty of describing adequately the rather slight differences between the two species and because each species has a uni- colorous phase. Most of the early refer- ences to P. dorsalis in Illinois were based on presumptions that this species would be found eventually in eastern Illinois or were obvious misidentifications of P. cinereus. Prior to 1948 the only published record for dorsalis was almost certainly in error, as the record, based on specimens AMNH 23297-3301 and labeled Urbana, Illinois, has not been substantiated by additional collections. Moreover, suitable habitat for this species is completely lacking in the vi- cinity of Urbana. During the first season of field work for the study reported here, dorsalis was found to be common in south- eastern Illinois, as various authors had pre- dicted, and the species is now known in much of the Shawnee Hills region. as well as in eastern Vermilion County, fig. 44. It is now apparent that P. dorsalis has long been collected in southwestern Illinois but, until recently, has been invariably mis- identified as P. cinereus. The status of the Mississippi River bluff population is still Vol... 25;7Arte 4 Fig. 44.—Distribution of Plethodon dorsalis. Hatching indicates the presumed range of the species in Illinois; solid circles indicate local- ities represented by specimens examined dur-— ing this study. The lower map depicts the total range of the species in the United States. uncertain. There is some possibility that it is a colony of hybrid origin, inasmuch as” the population combines certain characters’ of dorsalis and Ozarkian cinereus and there are good zoogeographic reasons for assuming that a segment of Ozark cinereus may have been isolated on the Illinois side of the Mississippi River. However, except for its” minute geographic range, there is equal jus- tification for describing the population in southwestern Illinois as new. The hiatus between its range and that of typical dor- salis, fig. 44, seems to be real, suggesting that the population has attained reproduc tive isolation. Until more definite evidence becomes available, however, it seems advis- able to recognize it as an aberrant colony of P. dorsalis. It is regarded by some current students a consanguineous with the Ozarkian Plethodon cinereus angusticlavius, but I consider it dis tinct. : November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS te ~ tease Fig.45.—An adult Plethodon glutinosus glutinosus from Richland County, Illinois. groundcolor is black; the dots are milky white. Plethodon glutinosus glutinosus (Green) Slimy Salamander Salamandra glutinosa Green 1818:357 (type locality: vicinity of Princeton, New Jersey). Plethodon glutinosus, Yarrow 1882a:155. Plethodon glutinosus glutinosus, Bishop 1943: 250. Diagnosis.—A medium-sized terrestrial salamander (largest Illinois specimen 167 Table 14.—Geographic variation in Illinois Plethodon glutinosus glutinosus. parentheses are numbers of specimens. The mm. in total length), fig. 45, black or blue- black above, with white flecks; usually frosted with white or silvery white on lower sides and uniformly black or black with occa- sional light flecks below; 14 to 15 costal grooves; usually | to 4 costal folds between toe tips of adpressed limbs; 12 to 22 vomer- ine teeth; tail of adult usually slightly longer than snout-vent length, and often lighter ventrally than belly. Figures in WABASH SOUTHERN SHAWNEE peer aoe =) Borper (15) Division (17) Hixuis (15) Couns) Range Mean Range Mean | Range Mean Range | Mean Snout-vent length (Seite eee eo AS 527601 one ote 490-68 .2). <==. ..- 577 O/iles2) |\ee eee AA RRE DH ()| Pees es Total length (mm.).| 107-167 |........ HOOSIASS |i. eee ce P4163 Hass eee (VANE Srila Seen ce Tail length as per- centage of total lengathiwryrsc as cous SOROS SSeS SA aD emo 55 no s4 4956 Ore | Does SOs —oo aol aoe5 Combined vomerine tooth count...... 14-23 16.8 11-20 Seed 15-22 18.0 12=22 17.0 Folds between toes of adpressed limbs..| 14-41% Py 2-5 1-314 DD) 2-3% DET 1-314 Dies Per CENT OF Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS Costal grooves 14 . 80 24 0 20 Costal grooves 15.. 20 76 100 80 Lateral blotches. 67 47 60 93 Small spots....... 33 53 40 7 58 Variation.—In this salamander, the male differs from the female in having a notice- able mental gland or a circular light spot that indicates the position of the gland. Many males have in addition prominent nasolabial swellings. Young specimens, less than 40 mm. in length, possess proportionately larger heads, more prominent eyes, and shorter tails than adults. Specimens less than 70 mm. in total length often have a brownish cast and the skin under magnification appears closely punctate with white. Superimposed on the small round dots are occasional larger light flecks that are most pronounced on the sides. In the smallest specimens at hand the venters are dull gray; in half-grown speci- mens the venters are dark, and the chins and undersides of the tails are light; and in adults the undersides of the tails and feet are lighter than the chins and bellies. Geographic variation within the state is seen in the tendency toward a relatively low costal groove count, long tail, and large maximum size in individuals from the Wa- bash Border counties (Clark and Vermil- ion), table 14. Habits.—Slimy salamanders are usually found under logs or rocks, but at night and on rainy days they may be seen wandering abroad. They are quick and so slimy that they are difficult to pick up. The slime is sticky and hard to remove from the hands. During early spring these salamanders are abundant on wooded hillsides, but later in the season, as the ground dries out, they re- treat to moist situations, such as the inte- rior of rotten logs. Their food consists of arthropods and annelids. The life history of this common species is poorly known. The 10 to 20 eggs laid by the female are said to be suspended by a slender stalk within rock crevices or rotten logs. The female remains with the eggs. The entire larval period is spent within the egg; at hatching the young salamanders are ready for a terrestrial existence. Illinois Distribution—The slimy sala- mander occurs in forested areas throughout the southern half of the state, fig. 46; it is sporadic in occurrence at the northern edge of its range and on extensive floodplains. At the periphery of the range in Illinois, the occurrence of the species is correlated with relatively mesic forest and rock out- crops. Numerous forest areas, apparently ILtino1is NATURAL History SURVEY BULLETIN Vol. 28, Art. 1 suitable but without rock outcrops, in Coles County, for example, have been combed for this species without success, but wooded and rocky areas in adjacent Clark and Shelby counties have yielded slimy salaman- ders on almost every visit. Considerable field work in the lower Wabash River val- ley has not revealed this salamander there, even though the woods appear to be ideal plethodontid habitat. ords for the Mississippi River counties north of St. Louis is inexplicable, inasmuch as no obvious break in habitat occurs in the St. Louis region. The single published record for West Northfield, Cook County, in northern IIli- nois (Yarrow 1882a) has been justifiably deleted from the Cook County fauna by Schmidt & Necker (1935) on the basis of th ll Fig. 46.—Distribution of Plethodon glutin- The absence of rec- — ———— i Sei osus. Hatching indicates the presumed range © of the subspecies glutinosus in Illinois; solid circles indicate localities represented by speci-— mens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts” the total range of the species in the United States. November, 1961 its remoteness from the continuous range of the species and the absence of additional collections of the slimy salamander. Yar- row’s record was probably based on a mis- identified specimen of the superficially simi- lar Ambystoma laterale. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Jackson County: 5 mi. S Carbondale, near Murphysboro (Cagle 1942a); Mapr- son County: (Hurter 1911); Str. Crair County: (Hurter 1893). SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS a9 Desmognathus Baird This eastern genus includes nine species in the United States, some of which have several subspecies. One form occurs within Illinois. Desmognathus fuscus conanti Dusky Salamander Rossman Desmognathus fuscus conanti Rossman 1958: 158 (type locality: 2.1 mi. S Smithland, Livingston County, Kentucky). Desmognathus fuscus fuscus nec Rafinesque, Davis & Rice 18835:14. Fig. 47.—Adult Desmognathus fuscus conanti from Pulaski County, Illinois. The ground- color ranges from yellow or light red-brown to dark brown; the markings are usually some shade of brown. 60 Ittrnoris NaturAL History SurvEY BULLETIN Desmognathus fuscus, Schmidt & Necker 1935: 60. Desmognathus fusca fusca nec Ratinesque, Yarrow 1882a:159. Desmognathus fusca, Davis & Rice 1883a:27. Desmognathus nigra, Yarrow 1882a:160. Desmognathus fusca auriculata nec Holbrook, H. Garman 1892:358-9. Diagnosis.—A moderately stout, tan or brown salamander (largest Illinois speci- men 100 mm. in total length), fig. 47, with a distinct light line from the eye to the angle of the jaws; tail triangular in cross section; nasolabial grooves present; 13 or 14 costal grooves; toes of adpressed limbs separated by more than 3 costal folds. Variation.—Bishop (1941) reported that males of Desmognathus fuscus fuscus dif- fer from females by their larger size, broader and longer heads, longer hind legs, presence of villi rather than folds on the cloacal lips, presence of mental glands, en- larged premaxillary teeth, and the usual absence of vomerine teeth. Sexual variation in D. f. conanti is presumably similar to that reported for D. f. fuscus. No definite ontogenetic variation has been discerned in the Illinois series of D. f. con- anti. Eighteen specimens from Pulaski County vary as follows: snout-vent length 37 to 54 mm.; total length 63 to 100 mm.; costal groove counts 14 in 15 specimens, 13 in 1 specimen; separation of toes of adpressed limbs 2 to 414 (average 2.9) folds; vomerine teeth 0 to 1 in males, 9 to 16 (average 11.2) in females; groundcolor dark red- brown to light yellow. Some specimens are unicolorous; others have _ spotted, dashed, or vermiform markings. A male and female from Union County display characters well within the range of variation of the Pulaski County series. Habits.—Dusky salamanders occur in cold springs and are usually encountered by raking wet leaves or raising rocks at the margin of a spring or stream. These sala- manders are alert, active, and extremely dificult to capture because of their quick- ness and slipperiness. Their food consists of arthropods, annelids, mollusks, and other salamanders. Clusters of 10 to 20 eggs are deposited in nests near the water in both the spring and fall, according to Bishop (1941). The female remains with the eggs, which she Vol. 28, Art. 1 sometimes devours. Hatching occurs in | or 2 months, the length of time probably de- pending on temperature. The larvae make their way to water by wriggling. Transfor- mation occurs in less than a year. Illinois Distribution.—Despite the nu- merous literature reports of D. fuscus in Illinois, it appears that this species is re- stricted to a very few colonies in the ex- treme southern tip of the state, fig. 48. Al- though it is abundant in most of the east- ern United States, the nearest valid record — outside of Illinois is for extreme western Kentucky rather than for Indiana, suggest- ing that the species entered southern IlIli- nois via the Mississippi River valley. One specimen (USNM 3823), which has been reported from Illinois as D. nigra and assumed to be D. fuscus by many authors, is actually a specimen of D. quadramaculata Fig. 48.—Distribution of Desmognathus fus- cus. Hatching indicates the presumed range of the subspecies cozanti in Illinois; solid circles indicate localities represented by speci- mens examined during this study. The lowe map depicts the total range of the species i the United States. November, 1961 and obviously has incorrect locality data. The specimens MCZ 2054 and 2056, labeled as from Normal, Illinois, are D. fuscus, but undoubtedly they are from some other state. The record of Hankinson (1915) for Coles County was questioned by Dunn (1926); almost certainly Hankinson con- fused Desmognathus with larval Eurycea. Yarrow (1882a) and other authors reported dusky salamanders from Mount Carmel, Wabash County, probably on the basis of Robert Ridgway’s recollection of these sala- manders. A series of Desmognathus, sup- posedly collected at Olney, Richland County, by Ridgway, is extant in the HJVC col- lection; since this series also includes speci- mens of California newts, it cannot be given serious consideration. The Union County specimens collected by “Black and Twomey” in 1935 and reported by P. W. Smith (1948) may have incorrect locality data, since repeated attempts to find the species in the same spring have been unsuccessful. AMPHIUMIDAE The family Amphiumidae consists of a single genus, which occurs in southeastern United States. Amphiuma Garden This genus contains one species, which consists of two subspecies. One of these may eventually be found to occur in extreme southern Illinois. Amphiuma means tridactylum Cuvier Three-Toed Amphiuma Imphiuma tridactylum Cuvier 1827:7, pl. 1, figs. 4-6, pl. 2 (type locality: New Orleans, Louisiana); Goodnight 1937:301; Cagle 1941:2; Baker 1947:12; Baker 1948: 131; Brown 1950:25. mphiuma means tridactylum, Schmidt 1953: ies. mphiuma means nec Garden, Weed 1923:50; | Goodnight 1937:300, 301. Diagnosis.—A large, eel-like, aquatic sal- mander without external gills and with 4 iny legs, each leg bearing 3 toes. Range.—This southern species has been ound northward in the Mississippi River alley almost to Illinois. The authors cited bove presumed that the species ranges into Illinois, but no specimens have been taken SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 61 within the state despite efforts of a number of collectors. The species is known in west- ern Kentucky, only 25 air-line miles south of Cairo, Illinois (S. A. Minton, personal communication), and it is accordingly a pos- sibility for the Cairo region. PROTEIDAE One genus of this family occurs in east- ern North America. Necturus Rafinesque The genus contains four species, one of which is polytypic and is widely distributed in eastern North America. The nominate subspecies of the polytypic species inhabits Illinois. Necturus maculosus maculosus (Rafinesque ) Mud Puppy Waterdog Sirena maculosa Ratfinesque 1818:41 locality: Ohio River). Necturus maculosus, Eycleshymer 1906:126. Necturus maculosus maculosus, Schmidt & Necker 1935:62. Necturus lateralis, Kennicott 1855:593. Menobranchus lateralis, Milner 1874:36, 62-3. Necturus maculatus, Cope 1889:23-7. (type Diagnosis.—A large aquatic salamander (largest Illinois specimen 344 mm. in total length), fig. 49, with permanent bushy gills and only 4 toes on each foot; tail length less than 38 per cent of total length; head flattened, swollen laterally behind the eyes; snout truncate; groundcolor slate to brown- ish gray, with scattered black blotches on back; sometimes uniformly dark above, oc- casionally with numerous black dots. Variation.—Bishop (1941) noted that the male mud puppy differs from the female in having a longer vent, which has oblique wrinkles at the margin, a pair of papillae directed backward, and a curved groove bordering the posterior margin. The vent of the female is a simple slit. Five males and six females from Vermilion County display slight differences in relative tail length; tails of the males average 32.4 per cent of the total length and those of the females 34.1 per cent. Two juveniles from Illinois, 40 and 42 mm. in length, are dark brown, with a pair 62 ILtinois Natura History SurvEY BULLETIN Vol. 28, Art. 1 Fig.49.—A subadult Necturus maculosus maculosus from Vermilion County, Illinois. The groundcolor ranges from light gray to dark olive; the spots on the body are brown or black; the gills, dark red. of yellow dorsolateral stripes extending from the gills onto the tail. Bishop (1941) found that in New York the yearling sala- manders average 55 mm. in length and have a middorsal yellow-brown stripe, bordered on each side by dull yellow bands. He found that 2-year-old specimens averaged 83 mm. in length and had longitudinal stripes that were dimmed by the appearance of rounded dark spots over the back; 3-year- old salamanders averaged 113 mm. in length and had stripes that were dimmer; and 4-year-old specimens averaged 148 mm. in length and had essentially the pattern of adults. No geographic variation has been noted in the Illinois specimens of Necturus macu- losus. Individual variation, especially in color and pattern, is pronounced; in a fair- sized series, specimens may be present re- sembling many of the recognized species of the genus, at least in details of pattern. De- spite the variability of pattern, the Illinois specimens almost certainly belong to a single population. The largest Illinois series of N. macu- losus available consists of six males and five females from Vermilion County. ‘Total lengths range from 208 to 343 mm. and the tail length comprises 30.2 to 37.3 per cent of the total length. Vomeropalatine teeth vary in number from 24 to 35 (average 31.2). Costal grooves are 15 or 16, and the toes of the adpressed limbs are separated by 6.0 to 8.5 costal folds (average 7.4). All 11 specimens are distinctly spotted above. Three specimens have a narrow, midven- tral, light stripe; three have venters entirely light; and five have a sharply defined light stripe that is about half the width of the — venter. ' Seven specimens from western Champaign and Piatt counties are 235 to 344 mm. in~ length and vary as follows: tail length 31.3, to 35.6 (average 33.4) per cent of total length; costal grooves 15 to 17; toes of ad- pressed limbs separated by 6.0 to 9.5 (aver-— age 7.5) folds; vomeropalatine teeth 35 to 44 (average 40.1). Four of the seven are distinctly spotted above, and three are dark, two having the many black dots supposedly characteristic of the northern N. m. stictus. The venter color variation is similar to that in the Vermilion County series. Single specimens at hand from localities in other parts of the state are, for the most part, well within the range of variation of the above series. A specimen (INHS 1002) from Rock Island County is almost identi cal with a Wisconsin specimen of N. m. stictus. A specimen (INHS 1003) fro Massac County is much discolored but note worthy because of its extremely squat body. An adult (INHS 8041) from 3 mi. NE Fairmount, Vermilion County, is an albino. Habits.—Mud puppies or waterdogs oc cur in lakes, lagoons, rivers, and large creeks. They are frequently caught on hook and line by fishermen near ideal habitats, such as piles of driftwood that accumulate around bridge supports in moderate-sized rivers. Active throughout the year, they probably remain in deep water during the day. They are ugly, excessively slimy, and, although harmless, they are unpleasant crea- tures to handle. Their food consists of vari ous fishes, arthropods, annelids, and mol lusks. November, 1961 Bishop (1941) records that pairing of males and females occurs in the fall but that oviposition does not take place until late spring. A gravid female lays approximately 100 eggs, usually on the underside of a sub- merged rock or log. Each egg is 5 to 6 mm. in diameter and suspended in a jelly-like sac. The eggs require about 2 months to hatch. The young are described briefly in the para- graph describing ontogenetic variation. Illinois Distribution.—Necturus is state- wide in distribution and probably abundant in suitable streams in every Illinois county, fig. 50, but it is dificult to collect by usual collecting methods. The accompanying map reflects the parts of Illinois where the most intensive collecting has been done, rather than the actual abundance of the species. Collections have recently been augmented by specimens obtained with the aid of electric i fi ie | | i 3 } : | Fig. 50.—Distribution of Necturus maculo- us. The subspecies maculosus occurs through- ut Illinois. Solid circles indicate localities epresented by specimens examined during this tudy; open circles, localities represented by ublished records believed to be valid. The Ower map depicts the total range of the q in the United States. SmM1TH: AMPHIBIANS AND ReEpTILES OF ILLINOIS 63 shocking equipment that aquatic biologists are now using. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: CoLes County: Cooks Mill (Hankinson 1917) ; Cook County: Evanston (Milner 1874) ; Wilmette (Necker 1939c) ; Jackson Coun- ty: Big Muddy River (Cagle 19422) ; KANE County: Carpentersville (Schmidt & Necker 1935); Lre County: Sublette (Pope 19446); Mapison County: (Hur- ter 1893) ; MarsHALL County: Henry (H. Garman 1892); OcLte County: Oregon (H. Garman 1892); Prorta County: Pe- oria (H. Garman 1892); Rock IsLANpD County: Moline (Howard 1951); Wa- BASH County: Mount Carmel (Yarrow 18822); Witt County: Joliet (Howard 1951); Witi1ramson County: Crab Or- chard Creek (Cagle 1942a). SIRENIDAE This family includes two genera, both found in eastern North America. Siren Linnaeus The genus Siren contains one monotypic and one polytypic species. A western sub- species of the latter occurs in IlIlinois. Siren intermedia nettingi Goin Western Lesser Siren Siren intermedia nettingi Goin 1942:211-7 (type locality: Imboden, Lawrence County, Arkansas). Siren lacertina nec Linnaeus, Cope 1870:394. Siren intermedia, Noble & Marshall 1932:2. Diagnosis.—A large, eel-like salamander (largest Illinois specimen 457 mm. in total length), fig. 51, with 4 toes on each front foot, and no hind legs; 3 pairs of gills; body brown, black, dark olive, or bluish gray above, with or without small black spots; venter lighter than dorsum; margins of jaws with horny sheaths; 34 to 37 costal grooves, usually 34 or 35; venter and sides often marked with light flecks. Variation.— Males of this species exceed females in size. I am unable to determine the sex of the specimens in our series by any external characters. 64 ILLinois NaturAL History Survey BULLETIN Fig. 51.—An adult Siren intermedia nettingi from Pope County, Illinois. The color range from very dark brown to blue-black. In a series of eight specimens from Pine Hills, Union County, two are larvae. The smaller larva, 19 mm. from snout to vent and 24 mm. in total length, is boldly marked above with a light (red in life) band that extends from the gill tufts on one side around the snout to the gills on the other side of the head. This band is broadest o the edge of the truncate snout. A pair o interorbital dashes, a transverse band acro the occiput, and a middorsal stripe that ex- tends from the gill region to the tip of th tail also are red in life. The larger lary 44 mm. from snout to vent and 58 mm. i Table 15.—Geographic variation in Illinois Siren intermedia nettingi. Figures in paren theses are numbers of specimens. EXTREME Macoupin AND | FULTON AND SOUTHERN St. CLAIR Mason oa CHARACTERISTIC | ILuinors (12) | Counties (4) | Counties (2) Range Range Range Range | ae ee Snout-vent length (mm.)...... 69-254 109-290 133-312 268 Total length Gmm.).. 2 91-381 152-418 196-457 380 Tail length as percentage of | tofaluene thie seni eee. 19,4-35.7 28.2=32.3 S1e7 2908 Bd Sea nx earth BS SS ped yy ae Ne Ee i ee Bets | Per Cenr or | Per Cent or | Per Cent or | Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS Costal’grooves' 34.0). 5520.. 5 6. 60 0 0 100 Costal’grooves 3520 8 20S 40 100 100 0 November, 1961 . total length, differs in lacking the inter- orbital and occipital bars. The dorsal fin ex- tends well forward of the anus in both lar- -yae, whereas in adults the fin originates just behind a point opposite the anus. The tail length of the larvae comprises, respectively, 20.8 and 24.2 per cent of the total length. Subadults less than 250 mm. in total length have nail-like cornifications on the toe tips. In large adults the toes have blunt, horny | tips or no cornification at all. | No definite trends in geographic variation within Illinois have been discerned for the western lesser siren. A specimen from Ma- -son County (INHS 6553) with a total | length of 457 mm. appears to be the largest recorded for this salamander. There is con- siderable individual variation in the order of toe length, in color, and in distinctness of markings. Other variation for four small samples is to be found in table 15. _ Habits.—The western lesser siren, which is permanently aquatic, frequents swamps, ditches, and sloughs. Captured individuals squirm violently and they are difficult to hold because of their slipperiness. Cagle & Smith (1939) found, in a culvert in south- ern Illinois, an aggregation of 138 individ- uals that appeared to be hibernating. There is evidence, however, that this salamander usually is active throughout the winter. Its food consists principally of arthropods, mol- lusks, and worms. Bishop (1941) noted that the several hun- 'dred eggs, laid in early spring by the fe- male of this salamander, are deposited in hollows in the mud bottom of a pond. The eggs average about 3 mm. in diam- eter. Details are lacking regarding incuba- tion time and larval development. A larva taken May 15 was less than 30 mm. in total length. This specimen was kept in a cattle watering trough until July 1. During this time it metamorphosed and attained a total length of 111 mm., having increased its length approximately fourfold in 6 weeks. Illinois Distribution—The exact range of Siren in Illinois can be only guessed. Probably the population has been reduced in historic times to narrow fingers of flood- plain swamp that margin the medium-sized and large rivers of the state, fig. 52. In the Illinois River valley the species occurs north to Peoria County. The absence of records for counties in the upper Mississippi River valley is unaccountable, since the extens:ve SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 65 Fig. 52.—Distribution of Siren intermedia. Hatching indicates the presumed range of the subspecies mettingi,; solid circles indicate local- ities represented by specimens examined dur- ing this study; open circles, localities repre- sented by published records believed to be valid. The lower map depicts the total range of the species in the United States. river bottoms seem to offer ideal habitat. The statement that the species occurs in northern Illinois (Davis & Rice 1883a, 1883) was based on a specimen in the Northwestern University collection. No spe- cific locality was given, and the specimen has disappeared. The former occurrence of Siren in northeastern Illinois is possible, however, in view of records for Porter County, Indiana (Pope 19444). This salamander is common in the south- ern fourth of Illinois, but it is difficult to collect by conventional techniques. If spe- cial effort is made, it can be taken in num- bers. Many specimens can be secured in the Pine Hills swamp wth a minnow seine. I have heard reports of animals fitting the de- scription of Siren from Effingham, Fayette, and Jasper counties, in addition to the locali- ties plotted on the map, fig. 52. 66 Ittrnoris NATURAL History SurvEY BULLETIN Published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Cass County: Beardstown (Weed 1923); Mapison County: Alton (Cope 1875); Monroe County: (Hurter 1911); Perry County: 5 mi. E Du Quoin (Goin 1942) ; RANDOLPH County: (Hurter 1911); Craik County: (Hurter 1911); Union County: 5 mi. NE Jonesboro (Goin 1942) ; Union County State Forest (Cagle 1942a) ; WasasH County: Mount Carmel (Yar- row 1882a); WILLIAMSON County: 1 mi. NE Herrin (Cagle & Smith 1939) ; Johnston City, Marion (Cockrum 1941). M4 Veta srunoee "MN M \v 2 SLC LON \ MUTTON 2 “1 CTT ae 7 A “MH ren ‘ Merrie vris nm Auta TT THN EN hy Mtuinnny ry, MAA Vv ey a AC tin, quel \ OUT OES cS 4e OCCU MALU Whee N ‘ out ECO COSTS > M8 4 ry ton oon 2 en rintnraate™ we Me, ronan ene anay, ) Go 7) v7 u Mn, enn ayn ay Ww ah AT ET Vol. 28, Art. 1 Order SALIENTIA Frogs and Toads Twenty-one species and subspecies of frogs, treefrogs, and toads occur in Illinois. Members of the order Salientia may be divided into three rather artificial groups: the true frogs, the toads, and the treefrogs. The true frogs, in general, are terrestrial, but they are forced to remain near water because of their rapid rate of dehydration. — The toads are more resistant to desiccation and may occur far away from ponds and- streams. The treefrogs also are fairly re- sistant to desiccation and they are usually UA Ay “OO y, Nn "a “minus c 2 qsroea Q o ‘4 ? %, ‘Wy, a N \ ey My Ning Pecan wi we mq whaca aacaueten OO a 9 we “S “Merarnaa auc. Ae ON annes® x a HOG Ha jyrg qn OS 3 wi MLL OTT TA nut ES aan fe} e 4, ‘Wy, "Nn ¢ <7) "4 ‘ sai Win M reer eo a s \) % DD ry inw™ c 2 a Fig. 53.—Mouthparts of some Illinois tadpoles (4-/): A, Bufo americanus americanus; B, Scaphiopus holbrooki; C, Acris crepitans blanchardi; D, Pseudacris streckeri illinoensis; E, Hyla versicolor versicolor; F, Rana clamitans melanota; G, Rana pipiens sphenocephala; H, Rana sylvatica sylvatica; I, Gastrophryne carolinensis carolinensis; I, labial teeth; m, mandible; #, papillary fringe. November, 1961 arboreal in habits. Frogs and toads are pri- marily nocturnal, although they may be en- countered occasionally during the day. In size they range from the inch-long cricket frog to the 8-inch bullfrog. All Illinois salientians are predatory and partially or exclusively insectivorous. Most frogs and toads are alert and quick in their move- ments. Their ability to leap, their habit of concealing themselves, and their protective coloration aid them in escaping predators. Typically, the salientian life history begins anew each spring with migration to water. The males arrive first and utter their char- acteristic mating calls; the females follow in a day or so, and the clasping process or am- plexus occurs. The males fertilize the eggs as they are laid by the females; after ferti- lization the eggs develop jelly-like envelopes. The eggs may be single, in strings, or in packets. they may be attached to objects on the bot- tom of a pond or stream. Hatching occurs in a few days, and the tadpoles or larvae be- gin feeding on algae almost immediately. The tadpole, which is limbless, has modified mouthparts consisting of a horny beak and rows of labial teeth. The arrangement of the mouthparts is distinctive for all genera and for some species, fig. 53. When the tad- pole is a few weeks old, limb buds appear. The hind legs develop a few days earlier than the front legs. As the limbed tadpole grows, it spends more and more time at the edge of the water or at the surface. Grad- ually the tail is resorbed, and certain inter- nal changes take place. The newly trans- formed froglet, recognizable by the tempo- rary tail stub, has undergone important changes in the respiratory, circulatory, di- gestive, and skeletal systems, and by the end of summer the animal has acquired adult features, fig. 54. Variations from the typical life cycle mong the Illinois species consist of differ- nces in length of time required for attain- ng adulthood, differences in breeding sites, nd differences in breeding seasons. All of he Illinois species have an aquatic larval tage. Five of the 21 species and subspecies nown in Illinois have ranges centering to he south of the state. These are Scaphiopus holbrooki, Hyla avivoca, H. cinerea, Rana ipiens sphenocephala, and Gastrophryne arolinensis. The last species is of special They may be floating masses or SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 67 interest, inasmuch as the Illinois population seems to be a relict rather than a peripheral colony. Farther south the species is both generally distributed and abundant. Two Illinois frogs have ranges that cen- ter to the north of Illinois and that extend southward approximately to the central part of the state. These are Rana pipiens pipiens and Rana sylvatica cantabrigensis. Six essentially eastern frogs enter IIlinois from the east or southeast. These are Pseu- dacris triseriata feriarum, Hyla_ crucifer crucifer, H. versicolor versicolor, Rana clamitans melanota, R. palustris, and R. sylvatica sylvatica. Four predominantly western frogs have ranges that extend into or beyond Illinois. These are Bufo americanus charlesmithi, Pseudacris triseriata triseriata, P. streckeri illinoensis, and Rana areolata. Pseudacris s. illinoensis is deserving of special note be- cause the Illinois population is a relict with a hiatus of about 300 miles between it and the nearest population of P. s. streckeri. Four species are wide-ranging and cannot be classified readily. These are Bufo ameri- canus americanus, B. woodhousei fowleri, Acris crepitans, and Rana catesbeiana. Key to the Order Salientia (Frogs and Toads) 1. Horny cutting tubercles on heel of each foot, fig. 55 No horny cutting tubercles on heel of each fO0tN eee rier ie: 2. One elongate, spadelike ennie tuherele on each heel, fig. 55; parotoid glands round and inconspicuous ; eye pupils vertically elliptical (Pelobatidae) ............... bal Mitelmb mone tice: Scaphiopus holbrooki Upper and lower horny tubercles on each heel, fig. 56; parotoid glands prominent and elongate ; eye pupils horizontally elliptical (Bufonidae) 3. Venter plain or with a necklace of small spots across breast; maximum _ snout- vent length 75 mm. Venter completely spotted or mottled with dark; maximum snout-vent length 95 mm. ......Bufo americanus americanus 4. Dorsal dark spots on body small, each usually including a single tubercle; tib- ial warts distinctly larger than femoral warts Bufo americanus charlesmithi Dorsal dark spots on body large, each usually including many tubercles; tibial warts no larger than femoral warts Cai ieee Bufo woodhousei fowleri 5. Transverse fold of skin behind head ; head less than one-fourth snout-vent length; 68 Intrnoris NaturaL History SURVEY BULLETIN EYE? Vol. 28, Art. 1 10. TARSUS Fig. 54.—Lateral view of a frog. tympanum absent (Microhylidae) ” Gastrophryne carolinensis carolinensis No fold of skin behind head; head ap- proximately one-third the snout-vent length; tympanum present ...... Poe Terminal toe pads and intercalary carti- lages present, fig. 57 (Hylidae) 32..-- 7 Terminal toe pads and intercalary carti- lages absent, fig. 58 (Ranidae)...... 14 . Toe pads scarcely wider than penultimate joints; snout-vent length less than 35 8 ZA VSG 111 t ER ira te eel RGA CROSS O O 1 Toes fully webbed; back with numerous WWAEtS 4 oe Acris crepitans blanchardi Toes unwebbed, or web restricted to a flange on side of each digit; back smooth eye beyond shoulder; light, straight- edged maxillary stripe; no suborbital spot; body flattened and elongate... 10 Tibia 47 per cent or more of snout-vent length; dorsal pattern weak; longitud- inal stripes, if present, each usually less than one-half width of interspace...... Sere _. Pseudacris triseriata feriarum Tibia 46 per cent or less of snout-vent length; dorsal pattern usually of distinct longitudinal stripes, each stripe as wide \ Figs. 55-58.—Characteristics of frogs: 55, tart g a vo oe foot of Scaphiopus; 56, foot of Bufo; 57, digi of Hyla, showing intercalary cartilage and terminal pad; 58, digit of Rana. | . November, 1961 a, 12. 13. 14. 15. 16. Bi. 18. 19. 20. SMITH: as the space between stripes / Pseudacris triseriata triseriata Groundcolor tan or pink, with a distinct dark X-mark on the back; unders.de pink or yellow...Hyla crucifer crucifer No X-mark on back; dorsum unmarked or marked with blotches; venter gray SSE TLL a a a ee ed 12 Rear of femora mottled; suborbital light spot present; back variable in color, usually with a star-shaped dark blotch Rear of femora unmarked; no suborbital light spot; back green, without a star- shaped blotch....... Hyla cinerea Rear of femora green, with dark reticula- tions; snout-vent length under 50 mm. a, SSC ee Hyla avivoca avivoca Rear of femora orange or yellow, with dark reticulations; maximum snout-vent length 60 mm..Hyla versicolor versicolor A pair of dorsolateral folds extending down back, fig. 54; tympanic fold in- conspicuous ... Dorsolateral folds ‘absent; tympanic fold well developed ...... Rana catesbeiana Dorsolateral folds terminating just beyond PENA KOMI ESA Sense vaceae aro Aha es wt 16 Dorsolateral folds extending length of DEVEL 5 la a ee 17 Venter heavily reticulate with black; maximum snout-vent length 70 mm.; upper jaw of male olive, throat dusky ..Rana clamitans clamitans X melanota Venter usually not heavily blotched or reticulate ; maximum snout-vent length 95 mm.; upper jaw of male bright green, throat chrome yellow. . _.Rana clamitans melanota No dark mask on side of head; dorsum with distinct spots 18 Dark mask passing through eye and tympanum; dorsal pattern plain or dashed, but without distinct spots...21 Jaws mottled; dorsal spots closely crowded; groundcolor milky white and visible only as t®acery around dorsal spots; maximum snout-vent length 110 mm. Rana areolata circulosa Jaws without mottling; dorsal spots not closely crowded; maximum _ snout-vent length 100 mm. See) Dorsal spots square or rectangular, regu- larly arranged in a double row between dorsolateral folds; concealed surfaces of legs and venter yellow Rana palustris Dorsal spots irregular in size and ar- rangement; concealed surfaces of legs andevientennwhite! 22. Ast 2- s.cral.: 20 Dorsal spots averaging larger than eye. usually distinctly light margined; snout usually with dark dorsal spot; breeding males with internal vocal sacs; ground- color green, tan, or brown Rana pipiens pipiens Dorsal spots averaging smaller than eye, not distinctly light margined; snout usually without spot; breeding males AMPHIBIANS AND REPTILES OF ILLINOIS 69 with external vocal sacs; groundcolor tan, brown, or gray-green .......... "Rana pipiens sphenocephala Skin between dorsolateral folds usually smooth and unmarked; tibia usually more than 55 per cent of snout-vent length; maximum snout-vent length 60 TM ares ee Rana sylvatica sylvatica Skin between dorsolateral folds often with secondary dorsal folds or with light or dark longitudinal markings; tibia usu- ally less than 55 per cent of snout-vent length; maximum snout-vent length 50 ee), BAS Rana sylvatica cantabrigensis ZF PELOBATIDAE This family is regarded by some authors as having one genus in North America and by others as including two genera. Scaphiopus Holbrook Two or six species in the United States and Canada are included in the genus Sca- phiopus, the number depending on the taxo- nomic viewpoints of various authors. One species, which belongs to typical Scaphiopus, is found in southern Illinois. Scaphiopus holbrooki (Harlan) Eastern Spadefoot Rana holbrookit Harlan 1835:105 (type local- ity: South Carolina; revised to Charleston by Schmidt 1953). Scaphiopus holbrookii holbrookii, Elder 1945: I ee Scaphiopus holbrookii, P. W. Smith 1948:2. Scaphiopus holbrooki, Burger, Smith, & Smith 1949: 130. Scaphiopus holbrooki holbrooki, Schmidt 1953: 58. Diagnosis.—A medium-sized toad (larg- est Illinois specimen 59 mm. from snout to vent), fig. 59, lacking cranial crests and tubercles on the soles of the feet; vomerine teeth present; an elongate, dark-edged, horny spade on heel of each foot; vertically ellip- tical pupils; paired pectoral glands; yellow- gray and brown mottled groundcolor, with a pair of crescentic light bars extending from eyes to middle of back; tubercles on dor- sum red tipped; chin and venter unspotted. Variation.—In this species, the male dif- fers from the female in having stouter fin- gers and black horny deposits on the upper surfaces of the first and second fingers. Dur- ing the breeding season males have conspic- uous subgular vocal pouches. 70 Ittino1is NATURAL History SurvEY BULLETIN Vol. 28, Art. 1 Fig.59.—Adult Scaphiopus holbrooki from Alexander County, Illinois. The predominant j color is dark brown; the crescentic dorsal markings are grayish yellow or bronzy; many of the © warts are tipped with red spines. Twenty specimens at hand fall into four size groups: 4 center about 26.5 mm.; 4 cen- ter about 30 mm.; 2 are about 45 mm.; and 10 range from 54 to 59 mm. from snout to vent. A female with a body length of 45 mm. contains eggs. The young toads differ from adults chiefly in their proportionately larger heads and greater wartiness. Speci- mens under 45 mm. have spines tipping al- most all the body warts, whereas larger toads have spines that usually are restricted to warts on the head and interparotoid re- gions. Juveniles have poorly defined tym- panums, and their dorsal tubercles are so arranged as to form two _ interparotoid ridges. Head length in the 20 specimens com- prises 33.9 to 38.5 per cent of the snout-vent length; head width 38.4 to 44.0 per cent; and tibia length 34.3 to 37.7 per cent. Adults vary in smoothness of skin, some large indi- viduals being completely smooth in the mid- back region. The color varies from brown to black, with yellow-gray to dirty yellow markings. Habits.—The spadefoot is subterranean and is usually found only in the breeding ponds. Most of our specimens have been ob- tained by following farmers’ plows or raising logs. Toads of this species can quickly bury themselves, rear end first, by scooping away soil with the spades on their heels. Their food consists of arthropods and annelids. Breeding of the spadefoot has been ob- served in May and August in southern IlIli- nois. A specimen plowed up in June con- fe wT lial | | pe | amt Fig. 60.—Distribution of Scaphiopus hol- brooki. Hatching indicates the presumed range — of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; the open circle represents a published record believed to be valid. The lower map depicts the total range of the spe- © cies in the United States. November, 1961 tained well-developed eggs. Apparently breeding may occur any time between March and September, the time depending on the distribution of the heavy summer rains. Moderate rains do not provide sufficient stimulus for breeding. The mating call is a nasal grunt, uttered frenziedly, and can be heard almost half a mile away. Eggs are laid in short, irregular strings that are at- tached to vegetation in temporary pools or flooded fields. Hatching reportedly requires only 1 or 2 days, and the tadpoles may trans- form in 2 or 3 weeks. The broad, short- tailed tadpole has distinctive mouthparts, ne. 53. Illinois Distribution—The species is known in Illinois only in the southern tip of the state, fig. 60. Although this species oc- curs farther north on the Atlantic Coast, the nearest records outside Illinois are in Kentucky rather than Indiana, suggesting that the species entered southern Illinois via the Mississippi River valley. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: Jack- son County: Makanda (P. W. Smith 1948). BUFONIDAE Only one genus of the family Bufonidae is represented in the United States and Can- ada. Bufo Laurenti This world-wide genus contains 15 spe- cies in the United States and Canada, most of which consist of several subspecies. Two species occur in Illinois. Bufo americanus Holbrook Many authors prefer to regard Bufo americanus and the southern toad, B. ter- restris, as conspecific and to recognize four subspecies of terrestris. For the most part, the ranges of the two toads are widely sep- arated; Neill (19494) has shown that where they are in contact they maintain their spe- cific identities. I am in accord with Neill in believing that the two are best consid- ered distinct species. B. americanus, as here defined, consists of three subspecies, a well- SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 71 marked Canadian race and two named races in the United States that are poorly defined morphologically and geographically. Two populations of B. americanus occur in Illinois. A small, rather plain, woodland animal occurs sporadically in the southern half of the state; and a large, well-spotted, prairie form is abundant in the northern half. It is uncertain if either of the Illinois toads is the B. americanus of Holbrook, as a cursory examination of material from scat- tered localities in the eastern United States reveals that eastern toads are intermediate between the two Illinois forms in most char- acters. The dwarf race in southern Illinois is provisionally referred to B. a. charlesmithi, because the paratypes I have examined are similar to the southern Illinois form, al- though appreciably smaller at sexual ma- turity. The large form of northern Illinois is provisionally, and reluctantly, referred to B. a. americanus, pending a complete rein- vestigation of the americanus complex. Bufo americanus americanus Holbrook American Toad Bufo americanus Holbrook 1836:75, pl. 2 (type locality: Maine through all the Atlan- tic States; revised to vicinity of Philadel- phia, Pennsylvania, by Schmidt 1953) ; Ken- nicott 1855:592. Bufo lentiginosus americanus, Yarrow 1882a: 166 (part). Bufo americanus americanus, Schmidt & Necker 1935:64. Bufo terrestris americanus, P. Smith 1947:30. Bufo americana, Grassley 1923:130. Bufo lentiginosus, Shelford 1913:187, 296. Bufo fowleri nec Hinckley, Nichols 1937:18-9. Bufo woodhousii fowleri nec Hinckley, Stille & Edgren 1948:197 (part). Diagnosis.—A large toad (largest Ill- nois specimen 90 mm. from snout to vent), fig. 61, with conspicuous, elongate, parotoid glands and_ strongly developed cranial crests; venter dark spotted or mottled; tu- bercles on dorsal surface of tibia promi- nently enlarged; dark dorsal spots including more than one wart in about 50 per cent of individuals; head length usually less than 30 per cent of snout-vent length; parotoid gland length usually less than 21 per cent of snout- vent length. Variation.—The male of the American toad differs from the female in being of smaller size and in having stouter first and 72 I~ttinors NATURAL History SurvEY BULLETIN second fingers, horny deposits on these digits, and vocal pouches. Juveniles differ from adults chiefly in hav- ing poorly developed cranial crests and in- conspicuous tympanums. In details of pattern and proportions, no marked differences are apparent between subadults and adults. Newly transformed toads, however, are black and have light tubercles. The most pronounced geographic varia- tion is found in samples from Coles County and Adams and Hancock counties, near the southern edge of the range. Specimens in these samples are intermediate in size be- tween the prairie form and the dwarf form. They approach the dwarf race in their pro- Vol. 28, Art. 1 portionate head length, relative parotoid length, and reduced ventral patterns. Other samples from the northern half of Illinois are rather homogeneous. The variation is summarized in table 16. Habits.—The original habitat of the American toad is problematical since the species is best known in gardens, orchards, and lawns. Individuals are encountered both in woods and in fields. The species has been presumed (P. W. Smith 1947) to be essen- tially a prairie animal, since in eastern IIli- nois the range terminates abruptly at the Shelbyville Moraine. On a spring night these toads can be heard singing in almost every flooded field north of the moraine. Fig. 61.—Dorsal and ventral views of a subadult Bufo americanus americanus (left) from La Salle County, Illinois, and an adult Bufo americanus charlesmithi (right) from Pope County, Illinois. The dorsal groundcolor of both subspecies ranges from dark brownish black to olive and even to rusty red. The red color is particularly common among males of B. a. charlesmithi. November, 1961 Juring the day American toads hide in hrubbery or bury themselves in the soil, oming forth at dusk to feed on insects and yorms. The peak of the breeding season is mid- \pril. The call is a sustained, high, musical rill and can be heard during the day as well SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 73 ern half of the state, americanus is quite general in its occurrence. In spring breed- ing aggregations are surprisingly large even in some areas where toads are seldom seen at other seasons. Nichols’ (1937) study of the larval mouth- parts of B. w. fowleri undoubtedly refers to Table 16.—Geographic variation in four samples of sexually mature Illinois Bufo amer- canus americanus. Figures in parentheses are numbers of specimens. EXTREME CHAMPAIGN- Cc ADAMS- NorTHERN SANGAMON Corer (12 Hancock CHARACTERISTIC Iuirnots (11) Counties (17) mee) Counties (7) Range Mean Range Mean Range Mean Range Mean ee vent length ee cinch Stee See Pease: lOOeS— 90.0). ac csc 2 19D. 2a IAS Ol. os vce AZ SO-6720).,. 2c. eee ad Teen as per- centage of body MEBEER So. cc sss 3 26.8-30.9| 28.6 |26.7-30.2] 28.6 |26.4-32.9) 29.2 |27.6-31.2| 29.9 arotoid length as percentage of body Renmthinnitse west: 17.5-22.8) 19.4 |15.6-21.5| 19.0 |16.6-23.4) 20.4 |18.8-23.8) 21.4 entral pattern*.... 3-5 B29 3-5 4.1 2-5 3.0 2-4 32 Per CENT OF SPECIMENS Per CENT OF SPECIMENS Per CENT OF SPECIMENS Per CENT OF SPECIMENS 64 35 58 100 *Ventral pattern indicated by index number. The index numbers have been assigned as follows: a few scattered spots on the breast region, 2; r with a single pectoral spot, 1; ; entire venter spotted, 4; venter predominantly dark, 5. s at night. The female lays several thou- and eggs in long strings, and these strands aay extend for several feet along the bottom f a pond or ditch. Each jelly string com- 10nly contains double or sometimes triple ows of eggs, the individual eggs ranging rom 1.2 to 1.4 mm. in diameter. Hatching ccurs in approximately a week. The small lack tadpoles, easily recognized as toad arvae, fig. 53, are almost identical in all he Illinois species of Bufo. Metamorphosis ccurs in early June. Heavy rain late in the season may stimu- ate singing by small, newly matured males. Illinois Distribution—With the excep- on of the sand areas, where Bufo wood- ousei fowleri predominates, B. a. ameri- nus is the common toad of the northern alf of Illinois, fig. 62. In much of the black il prairie it is the only toad. Although is form is less conspicuous in northern IIli- ois than fowleri appears to be in the south- venter immaculate a zone of dark spots across the breast, B. a. americanus, since both breeding dates and locality preclude the possibility of his specimens being fowleri. Although undocumented by _ specimens, published records for the following locali- ties are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Calumet City (Schmidt & Necker 1935); Evanston, Morton Grove (Necker 1939c); West Pullman (Hubbs 1918); Wilmette (Necker 1939c); Win- netka (Hubbs 1918); Wolf Lake (Schmidt & Necker 1935) ; Du Pack County: Down- ers Grove, Glen Ellyn, Naperville (Schmidt & Necker 1935); Kane County: Batavia, West Dundee (Stille & Edgren 1948); LakrE County: Fox Lake, Half Day (Schmidt & Necker 1935); Waukegan (Hubbs 1918); SrEPHENSON CoUNTY: Freeport (H. Garman 1892) ; Witt Coun- ty: Joliet (Hubbs 1918); New Lenox (Schmidt & Necker 1935). 74 Bufo americanus charlesmithi Bragg Dwarf American Toad Bufo terrestris charlesmithi Bragg 1954:247 (type locality: 1.8 mi. S, 7 mi. E Norman, Cleveland County, Oklahoma). Bufo lentiginosus americanus nec Holbrook, ?Yarrow 1882a:166 (part). ?Bufo americanus nec Holbrook, Burt & Burt 1929:2. Bufo americanus americanus nec Holbrook, Cagle 1942a:179. Diagnosis.—A small to medium-sized race of Bufo americanus (largest Illinois specimen 69 mm. from snout to vent but usually less than 60 mm. at sexual matur- ity), fig. 61, differing from B. a. ameri- canus in the following characteristics: smaller size; plain or sparsely spotted ven- er; head length usually more than 30 per cent of snout-vent length (in 80 per cent of specimens); somewhat greater parotoid length; dorsal spots, if present, small and including a single wart (83 per cent of speci- mens). Remarks.—Although the dwarf form (B. a. charlesmithi) and the large form (B. a. americanus) are difficult to distinguish because of the overlap in characters, there is little doubt that these two forms repre- sent distinct biological entities in Illinois. Whatever its status, the dwarf race has a considerable range. Parker (1939) illus- trated a specimen from Reelfoot Lake, Ten- nessee, where it is reportedly uncommon, and I have seen specimens in central Arkan- sas and southern Missouri. Table 17.—Geographic variation in Illinois Bufo americanus charlesmithi. parentheses are numbers of specimens. ILtino1is NATURAL History SurvEY BULLETIN 4 { ‘ ‘ Vol. 28, Art. 1 Variation.—Like the large form, B. a charlesmithi is characterized by sexual di- morphism. Also, there is some evidence that in B. a. charlesmithi the males tend to be unicolorous, whereas females have obscure, dorsolateral light bands on a reddish ground: color. j No information is available on ontogenetic variation. The few juvenile specimens avail- able are small replicas of the adults. 3 Geographic variation for three samples is summarized in table 17. The number, length, and proportions are for sexually mill ture specimens. The variation in dorsal an ventral patterns, however, is for both adults and juveniles. 3 Habits.—The dwarf American toad, un- common in Illinois, is apparently a fores' animal. Otherwise, it is probably sia to the large form in habits. Breeding aggr gations of the small form have been encoun- tered on a few occasions in flooded field and shallow ditches on the Mississippi Rive floodplain. Most specimens at hand, how ever, have been found in steep-sided excava- tions that were too deep for the toads to climb or jump from. The ecolegical rela tionships of this toad with Fowler’s toad nee study. The peak of the breeding season appears to be the first half of April. The call is prolonged, high trill that I cannot distin guish from the song of the large form. The eggs are laid in long strings, and there is single row of eggs within each string. Th individual eggs range from 1.5 to 2.0 mm, in diameter. Additional observations ar Figures i Pore County CHARACTERISTIC Snout-vent length (mm.). 52.8-— Head length as percentage ‘of body length 29. 8- Parotoid length as per cent of body length|21.8— Ventral pattern index* Range ; Mean {Range (9) Mean |Range (5) Be ee 42.8-56.0|........|48.0-69.5].. ag 31.8 |28.6-34.2} 31.6 |28.8-31.8) 31.1 22.4 |18.4-23.4] 21.3 |19.4-24.2 Me: Range M ean (13 ean |Range (7) | 255 1-4 297 Unton County | Monroe County *Ventral pattern indicated by index number. The index numbers have been assigned as follows: a few scattered spots on the breast region, or with a single pectoral spot, 1; 3; entire venter spotted, 4; venter predominantly dark, 5 venter immaculat 2; a zone of dark spots across the breas a, November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS a needed to confirm the apparent difference between the two forms in number of rows of eggs per strand. I have not seen tad- poles, but it is likely that transformation occurs in late May and early June. Illinois Distribution—The occurrence of B. a. charlesmithi is sporadic, fig. 62; this toad is subordinate in numbers to B. woodhousei fowleri even in the forested Shawnee Hills, where it is best known. Since adequate samples of B. americanus are not available from the Southern Division, the subspecific status of the toads from this area is uncertain. The rarity and the con- sistently small size of the few specimens ‘known from this part of the state strongly suggest the dwarf race. Fig. 62.—Distribution of Bufo americanus. Vertical hatching indicates the presumed range of Bufo americanus americanus in Illinois; horizontal hatching, the presumed range of Bufo americanus charlesmithi; crosshatching, | the area of intergradation between the two subspecies; solid circles indicate localities rep- resented by specimens examined during this cy: open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. The Richland County records of Cope (1889) and Gaige (1914) have not been accepted here, because Cope’s Olney mate- rial that is still extant contains only B. w. fowleri. Moreover, Mrs. Gaige in her paper failed to mention Fowler’s toad, which is so abundant in Richland County that it is in- conceivable it would have been overlooked. There is some doubt concerning the Marion County record of H. Garman (1892) and the Washington County record of Burt & Burt (1929), but since there are recent col- lections of B. americanus in Bond, Clinton, Macoupin, and Montgomery counties, Gar- man’s and Burts’ records may be valid. No records for either race of americanus are known for the Wabash Border division. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Mapison County: (Hurter 1911); Ma- RION County: Centralia (H. Garman 1892) ; St. Crarr County: (Hurter 1911) ; WASHINGTON County: Nashville (Burt & Burt 1929). Bufo woodhousei fowleri Hinckley Fowler’s Toad Bufo fowleri Hinckley 1882:310 (type locality: Milton, Massachusetts); Hubbs 1918:42-3. Bufo woodhousi fowleri, Necker 1938:2. Bufo woodhousei fowleri, Schmidt 1953:67. Bufo lentiginosus americanus nec Holbrook, ?Yarrow 1882a:166. Bufo lentiginosus lentiginosus, H. Garman 1890:189-90. Bufo americanus nec Holbrook, ?Gaige 1914:4. Diagnosis.—A medium-sized gray or greenish gray Bufo (largest Illinois speci- men 69 mm. from snout to vent), fig. 63, typically with 2 or 3 pairs of large dark blotches between the parotoid region and anus, each blotch containing 3 or more warts; tibial warts never conspicuously en- larged; belly never spotted; breast usually with a single pectoral spot in specimens from southern Illinois, often with numerous dim spots in specimens from northern and central Illinois; cranial crests present but not strongly developed; throat of male black. Variation.—In this toad, the male differs from the female in being smaller in size and in having a dark throat; also it has horny growths on the upper surfaces of the inner fingers. 76 I~trnors NatuRAL History SurveEY BULLETIN Juveniles differ from adults chiefly in size. The newly transformed toadlet is clearly recognizable as Fowler’s toad. The partially grown specimen lacks the clearly defined tympanum of the adult. The _ parotoid glands are proportionately larger. The paro- toid length of seven specimens less than 40 mm. in body length averages 21.7 per cent of the snout-vent length, whereas the aver- age parotoid length of seven adults over 58 mm. is 20.6 per cent. Vol. 28, Art. 1 The available series indicate an increasing frequency, from south to north, of individ- uals with spotted breasts. This variation is not strictly clinal in nature, but a general trend is discernible, as shown in table 18. It is noteworthy that all of the 23 specimens available from the Henderson-Mercer coun- ty sand area in northwestern Illinois are spotted beneath and would therefore key out as B. americanus by the most frequently em- ployed character in anuran keys. Fig. 63.—A subadult Bufo woodhousei fowleri from Tazewell County, Illinois. The ground- color is light gray, tan, or greenish gray; the spots are dark brownish black. Table 18.—Geographic variation in ventral pattern of Illinois Bufo woodhousei fowleri. Figures in parentheses are numbers of specimens. SouTHERN HALF CHARACTERISTIC OF Itiinots (133) Breast spotted (per cent of specimens with)........ 18.2 Pectoral spot only (per cent of specimens with). ..... 81.8 NortH-CENTRAL [LLtNors (47) ExTREME | NorTHEASTERN Ivtinors (14) — ExTREME NorTHWESTERN ILttNots (23) 100.0 45.3 0.0 —. November, 1961 Habits.—Fowler’s toad is one of the most conspicuous amphibians in the southern half of Illinois and it is abundant in almost all suitable habitats. It may be encountered day or night; during the hottest part of the summer it is found less frequently during ff : = il Fig. 64.—Distribution of Bufo woodhousei. Hatching indicates the presumed range of the subspecies fowleri in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. the day than at night. This toad feeds on insects and probably on earthworms; cap- tive individuals, however, are reluctant to eat worms. Breeding occurs from late April until late June, the peak occurring in mid-May. The song is a prolonged nasal scream. The eggs are laid in long strings similar to those of B. americanus charlesmithi. Hatching oc- curs in approximately a week, and the tad- poles transform from late June through July. SmiITH: AMPHIBIANS AND REPTILES OF ILLINOIS Tif! Illinois Distribution—Fowler’s toad is extremely common in the southern half of Illinois, fig. 64. In west-central Illinois, it is abundant along the Mississippi and IIli- nois rivers, which provide sand areas or sandy floodplatns. In the Mississippi River valley north of Mercer County, an area containing seemingly ideal habitat of sand prairie, records for Fowler’s toad are lack- ing, despite considerable field work in north- western Illinois and adjacent Iowa. In east- central Illinois, these toads are extremely sporadic in occurrence in the black soil north of the Shelbyville Moraine. Where B. woodhousei fowleri and B. a americanus occur together in northern IIli- nois, there is a tendency for fowdleri to oc- cupy sandy areas and stream or lake mar- gins. Evidence that a combination of soil type and temperature is more important than competition with the American toad in de- termining the range of B. w. fowleri is given by (1) a close correlation of species abundance and soil type in eastern Illinois and (2) a northward extension of the fow- leri range along the shores of the Great Takes, which presumably moderate the cli- mate. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: JouHnson County: 20 mi. N Metropolis (Blanchard 1924b); Putask1 County: Villa Ridge (H. Garman 1892). HYLIDAE This world-wide family contains four or five genera in the United States and Can- ada, the number depending on the viewpoints of various authors. Acris Dumeéril & Bibron Many authors regard the strictly North American genus Acris as monotypic and re- fer the several described, but poorly defined, subspecies to Acris gryllus Le Conte. The conspecificity of Coastal Plain gryllus and inland crepitans has not been demonstrated, however, and the race occurring in Illinois is accordingly considered a subspecies of crepitans. The cricket frogs in Illinois seem to belong to a single, rather homogenous population. Their characters are in essen- 78 tial agreement with those of the recently de- scribed blanchardi (Harper 1947). Accord- ingly, the Illinois frogs are provisionally as- signed to blanchardi, even though this sub- species is doubtfully distinct from 4. crepi- tans crepitans. Acris crepitans blanchardi Harper Blanchard’s Cricket Frog Acris gryllus blanchardi Harper 1947:39 (type locality: meadow near Smallen’s Cave, Ozark, Christian County, Missouri). Acris gryllus gryllus nec Le Conte, Yarrow 1882a:169. Acris gryllus, S. Garman 1884:44. Acris gryllus crepitans X gryllus, Cope 1889: 325,. 331. Acris gryllus crepitans nec Baird, Yarrow 1882a:169. Acris crepitans, Schmidt & Necker 1935:64—5. Diagnosis.—A small hylid frog (largest Illinois specimen 31.2 mm. from snout to with digital discs scarcely fig. 65, vent), Intinors Natura History SurvEY BULLETIN Vol. 28, Art. 1 wider than penultimate joints; extensively webbed feet; pointed head; tibia 58 per cent or more of body length; usually a few to many dorsal warts; light line from each eye to shoulder; dark postfemoral stripe on each leg; numerous vertical, light bars on snout. Variation.—During the breeding season of Blanchard’s cricket frog the male is easily distinguished from the female by the discol- ored throat and vocal pouch. Other dimor- phism has not been noted in the Illinois se- ries. I have been unable to find ontogenetic variation other than size. A study of adequate series reveals only minor geographic variation for this frog in Illinois. There is some indication that speci- mens in the southern fifth of the state are relatively small, the largest of a series of 37 specimens from this region being only 28 mm. from snout to vent. The largest speci- mens in series from other areas exceed this Fig.65.—An adult Acris crepitans blanchardi from McLean County, Illinois. shy 1S The ground- oy we, ae See a color may be gray, brown, black, olive, or tan; the markings, when present, are green, olive, or t rusty red. ¢ : : November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 79 Table 19.—Geographic variation from north to south in tibia length to body length ratios of Illinois Acris crepitans blanchardi. Figures in parentheses are numbers of specimens. EXTREME Nortu- SouTH- EXTREME NorTHERN CENTRAL CENTRAL SOUTHERN CHARACTERISTIC Itiinots (34) ILurnots (19) ILLtnots (29) ILLinots (44) Range Mean Range Mean Range Mean Range Mean Tibia length as per- centage of body ct 55.6-69.6| 59.6 |55.3-70.0| 60.9 |55.0-69.9| 61.2 |55.9-67.8] 61.4 length by 1 to 3 mm. Data for 157 speci- Although undocumented by _ specimens, mens indicate that individuals from the northern half of Illinois tend to be more ru- gose than those from the southern half. The available data on color and pattern types indicate that individuals with green, or more rarely rust-colored, middorsal marks occur with greatest frequency in the Shaw- nee Hills division and with least frequency in the Mississippi Border counties. A slight leg-length gradient is discernible from south to north, but no east-west cline is apparent. The leg-length variation is sum- marized in table 19. Habits.—This cricket frog is the most common amphibian in Illinois, and almost any wet place affords suitable habitat. Al- though Acris is a hylid, it is like a true frog in habits. The digital pads are minute, and the species is aquatic and terrestrial but not arboreal. This frog is alert and capable of making leaps astounding for its small size. It is reluctant to hibernate and it has been found active as early as February and as late as December. Its food consists of mi- nute arthropods. Although the adult cricket frogs are able to tolerate near freezing temperatures with- out becoming inactive, the breeding season is late. Singing commences about the last of April in Illinois and continues throughout the summer. The males float on the surface or sit on masses of algae while uttering their metallic “gick, gick, gick.”’ The small eggs are deposited as surface films of about a half dozen in each packet; one female may produce over 200 eggs. The tadpole is eas- ily distinguished by its black-tipped tail. Metamorphosis apparently occurs from July through September, the time depend- ing on when the eggs were laid. Illinois Distribution—The cricket frog is abundant in all parts of the state, fig. 66. published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Deer Grove Park, Evanston, Wolf Lake (Necker 1939c); Du Pace County: Glen Ellyn, Naperville (Schmidt crepitans. Fig. 66.—Distribution of Acris The subspecies blanchardi occurs throughout Illinois. Solid circles indicate localities repre- sented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. 80 Intinors Natura. History Survey BULLETIN & Necker 1935); Henry County: Co- lona, Geneseo (H. Garman 1892); Jack- son County: 2 mi. S Elkville (Burt & Burt 1929) ; Kane County: Dundee (Stille & Edgren 1948); Geneva (H. Garman 1892); Lake County: Highland Park (Schmidt & Necker 1935); Fox Lake (Necker 1939c); McHenry County: Richmond (Schmidt & Necker 1935); Ma- coupIn County: Standard City (Owens 1941); Morcan County: Meredosia (Weed 1923); Octe County: Grand De- tour (Yarrow 1882a); Pror1a County: Peoria (H. Garman 1892) ; Perry County: Tamaroa (Burt & Burt 1929) ; TAzEWwELi County: Pekin (H. Garman 1892); Un- ion County: 7 mi. S Anna (Burt & Burt 1929); WapasH County: Mount Carmel (Cope 1889); Witt County: 3 mi. N Beecher (Burt 1935); Lockport, Marley (Necker 1939c); New Lenox, Wheatland Township (Schmidt & Necker 1935). Pseudacris Fitzinger This strictly North American genus of terrestrial hylids contains seven species, three of which consist of several subspecies. Two species are known in Illinois. Pseudacris triseriata (Wied) This species, as currently defined, includes three subspecies in the United States and Canada. Two of these occur in Illinois. For many years the three subspecies here as- signed to triseriata and the southeastern chorus frogs, nigrita and verrucosa, were considered subspecies of Pseudacris nigrita. Schwartz (1957) demonstrated that the forms nigrita and feriarum behave as full species in the Coastal Plain of South Caro- lina and recommended the taxonomic ar- rangement here employed. P. triseriata and P. nigrita are actually intermediate between the specific and subspecific levels of differ- entiation; for, although they are specifically distinct in South Carolina, Georgia, and Florida, they are not so in southern Mis- sissippi, where they behave as subspecies. Pseudacris triseriata feriarum (Baird) Upland Chorus Frog Helocaectes feriarum Baird 1854a:60 (type locality: Carlisle, Cumberland County, Penn- sylvania). Vol. 28, Art. 1 Chorophilus 360. Chorophilus feriarum, Cope 1889:341. Pseudacris feriarum, Stejneger & Barbour 1917:30. Pseudacris nigrita feriarum, Stejneger & Bar- bour 1933:32. Chorophilus triseriatus nec Wied, H. Garman 1892:343-5 (part). Pseudacris triseriatus nec 1938a:380 (part). Pseudacris nigrita triseriata nec Wied, Cagle 1941:6 (part). Pseudacris nigrita nec Le Conte, P. W. Smith 1948:2. nigritus feriarum, Jordan 1888: Wied, Schmidt Diagnosis.—A small hylid frog (largest Illinois specimen 32 mm. from snout to vent), fig. 67, without webbing between the toes; toes with slightly expanded discs; dorsum smooth to granular; venter gran- ular or pustular; a light maxillary stripe; usually a triangular-shaped interorbital marking ; distinct longitudinal lateral stripes; 3 longitudinal dorsal stripes or series of spots.or flecks derived from 3 stripes; tibia 47 per cent or more of snout-vent length; head length 32 per cent or more of snout- vent length; and often with a tan or red- brown groundcolor. Variation.—In this frog the male differs from the female in being smaller in size and in having slightly enlarged thumbs and longitudinal gular folds. During the breed- ing season, the throat of the male is dis- colored and the vocal pouch is evident be- cause of its dark color. Juveniles differ from adults chiefly in their proportionately ee heads and longer tibiae. Individual variation in this frog is pro- nounced both in pattern and in habitus. Typically, the pattern consists of a distinct stripe along each side and 3 weak, and often interrupted, dorsal stripes. Occasional specimens are flecked with uniformly dis- tributed dark markings above, and infre- quent specimens are unicolorous above. Other individuals are broadly striped above, as in Pseudacris triseriata triseriata. The groundcolor ranges from gray-green to red- brown. Some specimens are slender, with conspicuously widened heads; others are squat, differing from P. ¢. triseriata only by their longer legs. In a series of 42 specimens from the ex- treme southern tip of the state the tibia length is 43.6 to 58.4 (average 50.7) per cent of body length and the head length (for ——— a eee a November, 1961 SMITH: AMPHIBIANS AND RepTILEs OF ILLINOIS 81 23 specimens) 29.6 to 37.5 (average 34.5) (average 48.7) per cent of body length; per cent of body length. head length (for 12 specimens), 30.9 to 34.1 In a series of 20 specimens from the (average 32.3) per cent of body length. Shawnee Hills, the tibia length is 44.9 to 52.0 Geographic variation in P. t. feriarum Fig.67.—An adult Pseudacris triseriata feriarum from Saline County, Illinois. The ground- color is tan, gray, or light reddish brown; the weak dorsal stripes or spots are usually dark brown. Table 20.—Geographic variation in tibia length to body length ratios of Illinois Pseudacris triseriata feriarum X triseriata intergrades. Figures in parentheses are numbers of specimens. c =RSON- CLARK- JACKson- JEFFERSON Rigniaxs ee SALINE WaABASH ee RAWFORD County +3) Coons) CHARACTERISTIC Counties (16) Counties (16) OUNTIES Range Mean Range Mean Range Mean Range Mean Tibia length as per- centage of body BAB sas oetecg ss 42.6-51.1| 46.3 |43.6-54.7| 47.4 |43.3-51.1] 47.3 |39.0-53.7| 46.5 82 Intinois NatrurAL History SurRvVEY BULLETIN has been described elsewhere (Smith & Smith 1952). In Illinois the most pronounced variation is manifested by populations which intergrade with the northern, shorter-legged race, triseriata. Samples from the intergrad- ing area do not exhibit the regular, ac- celerated cline from long legs to shorter legs, as might be expected. Instead, the characters of the two races are so inter- mingled that one sample may be referred to feriarum while one from an adjacent locality may be referred to triseriata. The erratic nature of the intergrade population is illustrated by four samples, table 20. Habits.—P. ¢. feriarum is essentially a forest animal, occurring on floodplains and in mesic upland woods except during the breeding season, when it may be found around almost any type of temporary pool. In summer this frog is sometimes seen on the forest floor or perched on herbaceous plants in swampy places. It feeds on small arthropods. Breeding occurs in temporary ditches or pools from late February until May, the peak occurring in mid-March. The male sings while perched at the edge of a pool or floating in the water; its call is similar to the noise made by rubbing a thumbnail over the teeth of a comb. The female de- posits approximately 100 small eggs in Fig. 68.—An adult Pseudacris triseriata triseriata from McLean County, Illinois. groundcolor is tan, gray, or greenish gray; the dorsal stripes are dark olive or brownish black. Vol. 28, Art. 1 elongate clusters that are attached to vege- tation or sticks. Hatching occurs in a few days, and the tadpoles transform in May and June. Illinois Distribution.—This subspecies occurs in the southern tip of Illinois, fig. 69, and intergrades with P. ¢. triseriata throughout the Wabash River valley from Saline to Clark counties. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the distribution map by a_ hollow symbol: WasasH County: Mount Carmel (Cope 1889). Pseudacris triseriata triseriata (Wied) Western Chorus Frog Hyla triseriata Wied 1839:249 (type locality: Rush Creek, approximately 4 mi. S New Harmony, Posey County, Indiana) ; Kenni- cott 1855:593. Pseudacris nigrita triseriata, Hurter 1893:254. Pseudacris triseriata, Weed 1923:49. Helocaetes triseriatus, Baird 1854a:60. Chorophilus triseriatus triseriatus, 1882a:170. Chorophilus triseriatus, Cope 1889:343, 347. Pseudacris triseriatus, Schmidt 1929:10-1. Chorophilus nigritus nec Le Conte, Shelford 1913:195, 206, 283, 296. Pseudacris nigrita nec Le Conte, P. W. Smith 1948 :2. Yarrow The November, 1961 Pseudacris feriarum nec Baird, Pope 1919: 33-4. ?Acris gryllus nec Le Conte, Ridgway 1915: 94, 95. Diagnosis.—A subspecies of Pseudacris triseriata (largest Illinois specimen 36 mm. from snout to vent), fig. 68, differing from P. t. feriarum in having shorter legs (tibia less than 47 per cent of snout-vent length in 95 per cent of specimens) ; proportion- ately wider body and smaller head (head length less than 32 per cent of snout-vent length in 80 per cent of specimens) ; usual- ly a distinct triseriate dorsal pattern; and usually a gray, gray-green, or slate ground- color. Variation.—Sexual variation and onto- genetic variation are apparently identical in the two Illinois subspecies of P. triseriata. Individual variation involves occasional reduction of the striped pattern and differ- ences in proportions, although specimens of this race are somewhat less variable than those of feriarum. No marked geographic variation, exclusive of the intergrading populations described under P. ¢. feriarum, has been discerned, but there is an indica- tion that extreme northern Illinois speci- mens of friseriata may average a bit smaller than those from central Illinois. The ab- sence of a leg-length gradient has been pointed out elsewhere (Smith & Smith 1952). Variation in pattern and _ propor- tionate head size is similarly nongeographic. The leg-length variation in four samples is given in table 21. Habits.—The western chorus frog ap- pears in temporary pools and ditches in great numbers early in the spring, and its voice is the most familiar frog sound in Illinois. After the breeding season, this species is seldom seen, and its habitat is not well known. Occasional specimens have been taken in summer and fall under rocks, SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 83 grain shocks, or other objects. It is essential- ly a prairie animal, and it thrives in the most intensively cultivated regions of the state. Individuals encountered out of water progress by short, rapid hops and often try Fig. 69.—Distribution of Pseudacris triseri- ata. Vertical hatching indicates the presumed range of Pseudacris triseriata triseriata in Illinois; horizontal hatching, the presumed range of Pseudacris triseriata feriarum; cross- hatching, the area of intergradation between the two subspecies; solid circles indicate local- ities represented by specimens examined dur- ing this study; open circles, localities repre- sented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Table 21.—Geo¢graphic variation in tibia length to body length ratios of Illinois Pseudacris triseriata triseriata. Figures in parentheses are numbers of specimens. JASPER County (32) MorcaAn-Brown | Counties (20) Cook-LAKE Counties (30) CHAMPAIGN County (25) CHARACTERISTIC | Range | Mean Range | Tibia length as per- centage of body Meeneth...... 22... 40.3-45.9| 43.6 |39.6-44.5 Mean Range Range Mean Mean 42.0 |37.1-47.1] 42.5 |38.1-45.9 84 ILLiNo1is NATURAL History SuRVEY BULLETIN to secrete themselves under objects or in cracks in the ground. Its food consists of small arthropods. Breeding occurs from early March into May, the peak occurring in late March. The song, egg-laying habits, and develop- ment are presumably similar to those of P. t. feriarum, although both hatching and transformation occur later in the season than in feriarum. Illinois Distribution—P. ¢. triseriata occurs commonly throughout Illinois except in the southern tip of the state, where it is replaced by P. ¢. feriarum, and in the Wabash River valley, where it is replaced by a feriarum X triseriata intergrade popu- lation, fig. 69. Although undocumented by _ specimens, published records for the following locali- ties are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Deer Grove (Necker 1939c) ; Palatine (Schmidt & Necker 1935) ; West Northfield (Yarrow 1882a); Du Pace County: Downers Grove (Schmidt & Necker 1935); Kane County: Elgin (Schmidt & Necker 1935); LAKE County: Beach (Schmidt & Necker 1935); Fort Sheridan (Pope 1919); Fox Lake, Half Day, Highland Park (Schmidt & Necker 1935); Volo, Waukegan (Necker 1939c) ; Mapison County: Mitchell (Hurter 1893); Octe County: Oregon (H. Gar- Fig. 70.—Adult Pseudacris streckeri illinoensis from Cass County, Illinois. The groundcolor is tan, flesh color, or light bronze; the markings are light brown to chestnut brown. — oe Vol. 28, Art. 1 man 1892); St. CLain County: Bluff Lake (Hurter 1893); Witt County: Lockport (Schmidt & Necker 1935). Pseudacris streckeri illinoensis Smith Illinois Chorus Frog Pseudacris streckeri illinoensis, P. W. Smith 1951:190 (type locality: 3 mi. N Meredosia, Morgan County, Illinois). Pseudacris streckeri illinoisensis, Schmidt 1953: 76. Pseudacris feriarum brachyphonus nec Cope, Weed 1923:49. Pseudacris sp., Walker 1932:382. Diagnosis.—A medium-sized hylid frog (largest Illinois specimen 42 mm. from snout to vent), fig. 70, with a toadlike habitus; vestigial webs; intercalary cartilage; digi- tal pad smaller than penultimate phalanx; lateral dark stripe from snout to shoulder; upper jaw light, with a prominent, dark suborbital spot; a dark interorbital V- or Y-shaped marking; and groin the same color as the dorsal groundcolor. Variation.—In the Illinois chorus frog, the male differs from the female in having a vocal pouch and being smaller in size. During the breeding season the throat of the male is discolored. Newly transformed individuals of this subspecies are dull gray, and their dorsal pattern is inconspicuous. The single known subadult differs slightly in proportions from me a, November, 1961 mature specimens. This subadult, 28 mm. from snout to vent, has a tibia length 46.4 per cent and a head length 36.1 per cent of the snout-vent length. Ten adults at hand have tibia lengths 39.7 to 42.4 (average 41.0) per cent and head lengths 29.8 to 32.4 (average 30.8) per cent of the snout-vent lengths. The specimens obtained since the original description appeared (P. W. Smith 1951) have not appreciably altered the known range of individual variation. At the time of the original description, one of the sup- posedly diagnostic features of Pseudacris streckeri illinoensis was the reduced lateral stripe (82 per cent of specimens with dark stripe no larger than postorbital stripe). Examination of additional material reveals that this character is of questionable value. However, the diagnostic value of the groin color and groin pattern, the two principal characters utilized, has been substantiated by an examination of additional specimens of P. s. illinoensis, as well as of P. s. streckeri. In addition, the greenish ground- color of the dorsum, which is of frequent occurrence in P. s. streckeri, apparently never occurs in P. s. illinoensis. Approximately 75 per cent of the speci- mens available possess a dark, inverted Y-shaped marking on one or both shoul- ders, with the inner prong usually extend- ing to the middle of the back. The dorsum bears a few dark bars and _ occasionally round, dark spots posteriorly. Habits.—This frog is known only from specimens taken during the breeding season, and accordingly its habitat is unknown. It is abundant in the small area in which it is known; during the breeding season, choruses can be heard continuously along the highways in the area. P. s. illinoensis is terrestrial and probably similar to P. tri- seriata triseriata in behavior. On land it progresses by short, toadlike hops. Captives have eaten various insects that were ob- tained in a sweeping net such as is used for collecting insects. Breeding in this subspecies occurs from the first to the last of March. The call of the male is a series of short, loud, birdlike whistles. The female lays approximately 400 eggs; the number in each mass and the shape of the mass are not known. Large tad- poles taken in mid-May transformed in the jaboratory in late May and early June. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 85 Illinois Distribution.—Since originally described, this frog has been found in an additional Illinois county and in a sand prairie in extreme southeastern Missouri. The total known range, fig. 71, occupies only four Illinois counties and one locality Fig. 71.—Distribution of Pseudacris streck- eri. Hatching indicates the presumed range of the subspecies i/linoensis in Illinois; solid circles indicate localities represented by speci- mens examined during this study. The lower map depicts the total range of the species in the United States. in Missouri. To date, attempts to find the frog in other sand areas in the state have been unsuccessful, but there is some possi- bility that it occurs in the Oquawka sand prairie and perhaps also in the Iroquois- Kankakee sand area. The relationships of this subspecies and its nearest relative, which occurs in central Oklahoma and Texas, have been discussed in the original description of P. s. illinoensis. The discovery of this animal in central Illinois is of some zoogeographic importance in that it provides additional evidence to support the Prairie Peninsula hypothesis and 86 Ittinors NaturAL History Survey BULLETIN the occurrence of a post-glacial xerothermic period. Hyla Laurenti The cosmopolitan genus Hyla contains 12 or 14 species in the United States and Canada, the number depending upon the taxonomic viewpoints of different authors. Many of the species consist of two or more subspecies. Four species occur in Illinois. Hyla avivoca avivoca Viosca Western Bird-Voiced Treefrog Hyla avivoca Viosca 1928:89 (type locality: Mandeville, Louisiana) ; Harper 1933:230. Hyla phaeocrypta, Viosca 1923:96-7 (part). Hyla versicolor phaeocrypta, Wright & Wright 1933:134 (part). Hyla phaeocrypta phaeocrypta, Schmidt 1953: 71-2. Diagnosis.—A small, slender, smooth- skinned Hyla (largest Illinois specimen 36.5 mm. from snout to vent), fig. 72, with a gray Fig. 72—An adult Hyla avivoca avivoca from Union County, Illinois. The groundcolor varies from pale gray to light green to almost black; the markings are dark gray, brown, or black. or green groundcolor and usually an asym- metrical, star-shaped, dark dorsal blotch; distinct suborbital light spot; wash of green color in groin and on rear of thighs in which black or brown reticulations or spots are present; relatively large eyes (33 to 44 per cent of head length); tympanum 43 to Vol. 28, Art. 1 ; 59 per cent of eye diameter; and subartic-— ular pustule on outer finger of hand usually divided. Variation.—The male is _ considerably smaller than the female in this frog and it possesses either a discolored throat or longi- tudinal folds, which indicate the presence of a vocal sac. . No information on ontogenetic variation — is available for Illinois populations of Hyla avivoca avivoca. Hellman (1953) — noted that newly transformed frogs of the Florida population are about 13 mm. in snout-vent length, are pea-green above, and possess prominent suborbital light spots. Individual variation in a series of 31 Union County specimens is as follows: snout-vent length 27.8 to 36.5 mm.; head length 28.3 to 31.6 (average 29.9) per cent of body length; tibia length 45.0 to 52.7_ (average 48.5) per cent of body length; eye Pi ag tot haat Ah ae mo Fig. 73.—Distribution of Hyla avivoca, Hatching indicates the presumed range of the subspecies avivoca in Illinois; solid circles indicate localities represented by specimens examined during this study. The lower map depicts the total range of the species in the United States. November, 1961 33.0 to 43.5 (average 37.4) per cent of the head length; eye 28.6 to 35.3 (average 32.7) per cent of head width; tympanum 43.1 to 59.1 (average 49.1) per cent of eye diameter. The dorsal blotch is variable in size and shape. Metachrosis is well developed in H. a. avivoca, and living frogs may be light green, light enamel gray, or almost black. Habits.—The western bird-voiced tree- frog has been seldom collected except in breeding choruses, but its normal habitat is likely identical with the breeding site, which is cypress swamps. Breeding individuals are found above the water of the swamps, on vines, tree branches, or stems of Cephalan- thus. Captives usually change from gray or black to light green when placed in dry, well-lighted containers. Breeding in this treefrog occurs in south- ern Illinois from mid-May into August. The call of the male is a prolonged, quaver- ing, birdlike note. Eggs have not been found in Illinois. Hellman (1953) found that Florida females contain 600 or more ovarian eggs, which are subsequently laid in submerged packets. Hatching occurs in 3 or 4 days, and the larval period requires ed SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 87 about a month. The tadpole of both the Florida and Illinois populations is dark brown, with 3 to 7 red saddles and thin bronze-colored stripes on the head. Illinois Distribution.—This species is known to extend into Illinois only as far as extreme southern Jackson County, fig. 73. It is abundant in the floodplain swamps of western Union and Alexander counties, but efforts to secure specimens in_ similar swamps of adjacent Massac, Johnson, and Pulaski counties have been unsuccessful. Hyla cinerea (Schneider) Green Treefrog Calamita cinereus Schneider 1799:174 (type locality: Carolina; revised to Charleston, South Carolina, by Schmidt 1953). Hyla cinerea, H. Garman 1890:189. Hyla cinerea cinerea, H. Garman 1892:346-8. Hyla lateralis, Brendel 1857:254. Hyla cinerea semifasciata, H. Garman 1890: 189. Hyla carolinensis, Hay 1892a:585. Diagnosis.— A _ large, slender Hyla (largest Illinois specimen 56 mm. from snout to vent), fig. 74, bright green or olive- a Fig. 74.—A subadult Hyla cinerea from Union County, Illinois. The groundcolor is normally bright leaf-green, occasionally olive-green; the lateral stripe, white; the dorsal flecks are gold. 88 ILtinois NaTuRAL History SurveEY BULLETIN Vol. 28, Art. 1 green above, without markings or with frogs the last of May, however, indicating _ scattered, minute gold flecks; white lateral stripes extending onto shoulder region or beyond; smooth skin; and with a_longi- tudinal light stripe along the dorsal surface of the tibiotarsus. Variation.—The male of H. cinerea aver- ages slightly smaller than the female and has a wrinkled throat indicating the vocal pouches. Cagle (1942a) found that the newly transformed frog of this species is green only on the back of the head and that 12 days are required for the entire dorsum to become green. The subadult appears less elongate and the head length range is 31 to 36 per cent of the body length (in 10 juveniles under 35 mm.), whereas the head length range is from 30.0 to 31.5 per cent in the adult (six specimens over 40 mm.). The tympanum is evident in all of our material, but it is proportionately larger in mature specimens. Eighteen specimens from Alexander and Union counties, ranging from 22.6 to 55.8 mm. in snout-vent length, exhibit the fol- lowing variation: tibia length 48.4 to 55.0 (average 53.2) per cent of body length; lat- eral stripes present, extending no more than half the distance from tympanum to groin in 33 per cent, and more than half in 67 per cent. There are one to many small gold flecks, sometimes black-margined, over the back in each of our specimens. Habits——The green treefrog is one of the most colorful of Illinois amphibians. It is found in cypress swamps, along floodplain sloughs, and in cattail marshes. During the day it usually perches on a cattail blade, with its legs tucked underneath the body; because of its green color, it is difficult to see. Captives sometimes turn olive-green, particularly when cold, but most wild in- dividuals are bright leaf-green. Breeding in the green treefrog occurs from mid-May until August. The call of the male is a measured and monotonous “quonk, quonk, quonk.” A chorus imparts a distinct metallic sound, and the song has been compared to the sound of cowbells. Wright & Wright (1949) report that eggs are laid in small packets or films among floating vegetation, that hatching presum- ably occurs in a few days, and that the larval period is approximately 2 months. Cagle (1942a) found newly transformed that the eggs had been laid in late March or early April. Singing males have never been found earlier than May in southern Illinois. The life history of the species needs reinvestigation. ; Illinois Distribution—This species is known from the Mississippi and Ohio river floodplains in the extreme southern tip of Illinois, where it occurs in abundance, fig. 75. A Madison County record for cinerea, in which Hurter (1893) used the synony- mous name carolinensis, is puzzling, for Hurter leaves little doubt that he was familiar with cinerea, inasmuch as the species with which it might be confused were reported in the same paper. Some doubt remains, however, since Hurter in a later paper (1911) failed to mention the a = A ee a ht Fig. 75.—Distribution Hatching indicates the presumed range of the species in Illinois; solid circles indicate local ities represented by specimens examined dur- ing this study; the open circle indicates z locality represented by a published record believed to be valid. The lower map depicts the total range of the species in the United States. November, 1961 Madison County locality, although he cited specimens from southeastern Missouri. I have not been able to find the species any- where north of Union County. Hyla crucifer crucifer Wied Northern Spring Peeper Hyla crucifer Wied 1839:275 (type locality: Leavenworth, Leavenworth County, Kans- as); Schmidt 1929:10. Hyla crucifer crucifer, Pope 1944b:95-100. Hyla pickeringii, Kennicott 1855:593. Hyla pickeringi, Davis & Rice 1883a:28. Diagnosis.—A small Hyla (largest Illi- nois specimen 34 mm. from snout to vent), fig. 76, tan or brown, usually with a distinct SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 89 pinkish cast; a prominent dark X-mark on the back and a dark mark between the eyes; toe pads distinctly wider than penul- timate joints; snout projecting beyond mouth in lateral view; without suborbital light spot or light maxillary stripe. Variation.—The male in this diminutive hylid is somewhat smaller than the female and possesses longitudinal gular folds, which permit expansion of the vocal pouch. Dur- ing the breeding season, the throat of the male is discolored and saclike. Juveniles tend to have a less well-defined dorsal pattern and the groundcolor is usual- ly lighter. Geographic variation is not pronounced in the Illinois series. Spring peepers from Fig. 76.—An adult Hyla crucifer crucifer from Monroe County, Illinois. The groundcolor is pink or tan; the markings are brown. 90 ILLinois NATURAL History Survey BULLETIN Table 22.—Geographic variation in Illinois Hyla crucifer crucifer. are numbers of specimens. Vol. 28, Art. i Figures in parentheses — SOUTHERN EXTREME ILLINOIS Nortu- ExTREME SOUTHERN NortH OF CENTRAL NorTHERN | Kian gio peeee ee Ittinors (23) Hine (40) ILiiNots (9) ILuinors (4) —_—_—_—— Range | Mean Range Mean Range Mean Range Mean Snout-vent length (mm.), maximum. SLO ES Hae 91; Gide eee 830.0). .eeieee 22:51 see nae Head length as per- centage of body lempth nce sacs 27.9-34.7| 31.7 |28.2-34.7) 30.7 |28.9-31.3| 30.2 |29.3-33.4) 31.1 Tibia length as per- centage of body length: 2 Sacre joa 46.8-55.7| 51.2 |44.9-53.0) 48.9 |42.6-48.5) 46.0 |47.3-49.8] 48.7 Per CENT OF SPECIMENS Without dark ven- fralecks msec! 43 the northern part of the state, however, appear to be smaller in size and their venters are more often pigmented. The leg-length variation is irregular. Data for 76 speci- mens from four areas are summarized in table 22. The sample from extreme northern Illinois is actually from the northeastern corner of the state, and the strikingly shorter-legged frogs of this species from north-central Illinois are from the Illinois River sand area. Habits.—The northern spring peeper occurs in mesic forest, living in trees or on herbaceous plants. It is normally abundant around woodland ponds early in the spring but difficult to find later in the season. Late in the fall, however, the male, whose gonads are again ripe, may begin singing from the woods. The peeper feeds on various small arthropods. Breeding in this species occurs from early March to early June. The song is a soft, birdlike whistle and may be heard during the day or night at the peak of the breeding sea- son. Diurnal singers usually are in trees or hidden under the leaves of the forest floor; at night peepers sing from the edge of the water or on vegetation over the water. The female deposits her several hundred eggs singly, and each egz is attached to a stick or other submerged object. Hatching Per CENT OF SPECIMENS Per CENT OF SPECIMENS Per CENT OF SPECIMENS occurs in a few days, and the larvae trans- form in May and June. Illinois Distribution.— Apparently the northern spring peeper is state-wide in oc- currence, fig. 77; abundance varies widely in different parts of Illinois. In the northern half of the state it probably does not occur in small islands of forest surrounded by prairie or cultivated fields, but it is known — in the more extensive wooded areas along rivers. The absence of records from the Upper Mississippi Border counties prob- ably reflects the small amount of field work © in this region during the peeper breeding season; the species is known in adjacent Iowa and Missouri. re Where peepers occur, they are much in evidence in spring because of their abundance — and the carrying power of their penetrating — birdlike calls. In Illinois they are sporadic — in distribution. In adjacent Indiana a person can hear a continuous chorus of peepers as he drives along the highways in spring. 4 Although undocumented by specimens, published records for the following locali- ties are believed valid; most are indicated on the distribution map by hollow ae | Cook County: Homewood, Palos Par (Schmidt & Necker 1935); Lake County: — Beach (Schmidt 1929) ; Sr. Crain County: — (Hurter 1893). K November, 1961 Fig. 77.—Distribution of Hyla crucifer. The subspecies crucifer occurs throughout Illinois mainly in extensive wooded areas. Solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Hyla versicolor versicolor Le Conte Eastern Gray Treefrog Hyla versicolor Le Conte 1825:281 (type lo- cality: northern states; revised to vicinity of New York City by Schmidt 1953) ; Ken- nicott 1855:592. Hyla versicolor versicolor, Blanchard 1924): 534. Hyla versicolor phaeocrypta Cope 1889:375 (type locality: Mount Carmel, Illinois). Hyla phaeocrypta, Viosca 1923:96-7 (part). Hyla phaerocrypta, Burt 1928:630. Diagnosis.—A large Hyla (largest Illi- nois specimen 57 mm. from snout to vent), fig. 78, with a suborbital light spot on each side of head; usually a star-shaped or ir- regular dark blotch on the back; dorsum tubercular or pustular; digital pads dis- tinctly widened; posterior surfaces of thighs SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 91 with orange-yellow spots enclosed by a dark matrix or a loose reticulation of yellow and brown or black; a simple subarticular pustule on outer finger of hand usually present (70 per cent of specimens); tym- panum usually 52 per cent or more of the diameter of eye. Remarks.—Two Illinois populations are evident. In one, in the southern half of the state, the dark color on the rear of the fem- ora encloses round yellow spots and the dor- sal blotch is star shaped. In the other, in the northern half, the thighs are reticulated brown and yellow or uniformly yellow and the dorsal blotch is nondescript. Fig. 78.—An adult Hyla versicolor versi- color from Union County, Illinois. The ground- color varies from pale gray to light green to almost black; the markings are dark gray, brown, or black. 92 Ittinois NaturAL History SurveY BULLETIN Series intermediate between these pattern types are available from the Illinois River valley (the north-central Illinois sample in table 23). There is a great deal of individual varia- tion in specimens from any one locality, and the differences mentioned above are rather slight, particularly in preserved frogs. Ac- cordingly, all the Illinois series are pro- visionally referred to H. versicolor versi- color, pending a detailed investigation of geographic variation in the species. There is some possibility that the population in the southern half of Illinois is assignable to H. v. chrysocelis, inasmuch as the frogs there appear to be identical with compara- tive material from Arkansas. If chrysocelis is valid, its range requires redefinition. Variation.—In this treefrog the male is somewhat smaller than the female and, during the breeding season, is readily dis- tinguished from the female by the presence of the discolored vocal pouch. In the male a process of the pad at the base of the thumb extends onto the upper surface of the thumb, whereas in the female this pad is restricted to the ventral and inner side of the thumb. Newly transformed frogs of this species are green or gray-green. The characteristic Table 23.—Geographic variation in Illinois Hyla versicolor. Figures in parentheses are numbers of specimens. Vol. 28, Art. 15 suborbital light spot and the postfemoral reticulation are not evident, but both appear in frogs of about 25 mm. from snout to — vent. Proportionate head size and leg length — are much the same in adult and juvenile. The proportionate size of the tympanum increases with larger body size. Thus, in — 10 specimens under 28 mm. the tympanum — averages 52.5 per cent of the diameter of | the eye; in 22 specimens 28 to 36 mm. the — tympanum is 58.2 per cent; in 27 specimens © 36 to 45 mm. it is 60.1 per cent; and in 2 10 specimens over 45 mm. it is 62.4 per cent. ¥ In addition to the differences in post- femoral patterns mentioned under “Re- 3 marks,” both proportionate head length and — proportionate leg length decrease toward — the north, although the gradients are not — steep. These trends are illustrated in table 4 ras : Habits.—The eastern gray treefrog in- habits forested areas. Although a tree ani- mal, it is seen on the ground when it is nie grating to breeding ponds. In the summer, — particularly during dry weather, this iol lives in hollows of dead trees or under the bark of stumps or of moist, rotten logs. On ;: three occasions individuals have been found in pump spouts of abandoned wells. Meta- — chrosis in this treefrog is well developed, as SOUTHERN ExTREME ILLINOIS Nortu- EXTREME SOUTHERN NortTH OF CENTRAL NorTHERN Cit conn ater ILtinots (28) Bice 09) ILirnots (36) ILiinors (22) Range Mean | Range | Mean Range | Mean | Range | Mean Snout-vent length (rams). dere oe 2T6-5720| eee DAO S| oo de ae 22 GES 19) aoe 31.2-43.8| =. 2 eee Head length as per- centage of body lengthen. seein." 28.8-33.8] 31.5 |28.0-34.6] 30.7 |27.9-34.8| 30.4 |28.1-30.9| 29.7 Tibia length as per- centage of body lenetlincy eee 45.5-52.8| 48.2 |43.0-52.6| 46.9 |42.0-52.5| 46.9 |44.5-50.2) 46.5 — ee ee er i | SM Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS With postfernoral pattern of H. v. chrysoceHs.......s 75.0 69.0 34.5 0 Per CENT OF Per CENT OF Per CENT OF November, 1961 the species name implies, and individuals often blend so well with tree bark that they are difficult to discern. Captives vary from almost black (usually when cold and wet) to enamel gray or light green (under opti- mum conditions). Individuals found in shaded floodplains in the summer and fall may be quite conspicuous in color. In such habitats they often perch at the tips of dead branches, and their almost white coloration is in sharp contrast to the black tree limbs. The food of the gray treefrog consists of va- rious arthropods. Breeding in this treefrog occurs from late April into August, the peak occurring in late May. The season varies with latitude, and males may occasionally sing late in the fall, when their gonads have again ripened. Fig. 79.—Distribution of Hyla versicolor. The subspecies versicolor occurs throughout Illinois wherever there are wooded areas. Solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 93 The call of the male is a loud, guttural trill. Singing males may be in trees or bushes, on the ground, or in the water. The breeding sites are extremely variable, ranging from water-filled automobile tracks to creeks or lakes. The packets of two or three dozen eggs are loosely attached to vegetation at the surface of the water. Hatching occurs in a few days, and the larvae transform from May to August. The tail of the tadpole is boldly marked with red and black. Illinois Distribution—The eastern gray treefrog commonly occurs in forested areas over all of Illinois, fig. 79. It may be absent from small islands of forest surrounded by prairie, but it occurs in narrow strips of for- est along streams, even in areas predom- inantly prairie. Although undocumented by _ specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Cook County: Aux Plaines (Yarrow 1882a); Chicago (Schmidt 1929); Willow Springs (Schmidt & Necker 1935); Jack- son County: Murphysboro (Cagle 1942c) ; KANKAKEE County: Hopkins Park, Pem- broke Township (Necker 1939c) ; KENDALL County: Yorkville (H. Garman 1892): Knox County: Galesburg (H. Garman 1892); Lake County: Fox Lake (Necker 1939c); Half Day (Schmidt & Necker 1935); Highland Park (Schmidt 1929); McHenry County: McHenry (Stille & Edgren 1948): IsLAND COUNTY: Rock Island (H. Garman 1892); Union County: Anna (H. Garman 1892); WILL County: Custer Park (Stille & Edgren i948). Roek RANIDAE This family, which includes the typical frogs, occurs on all of the continents and ranges in latitudinal distribution from the Arctic Circle (North America) southward to Queensland (Australia). In the New World this large family contains only one genus. Rana Linnaeus This world-wide genus is represented in the United States and Canada by about 15 species, most of which consist of two or more subspecies each. Eight species and sub- species of Rana have been found in IIlinois. 94 I~tLinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 1 Fig. 80.—Adult Rana areolata circulosa from Marion County, Illinois. milky white; the closely crowded spots are brown or black. Rana areolata circulosa Rice & Davis Northern Crayfish Frog Gopher Frog Rana circulosa Rice & Davis 1878:355 (type locality: Benton County, Indiana; revised incorrectly to northern Illinois by Stejneger & Barbour 1943; corrected by Mittleman 1947; revised incorrectly to Richland County, Illinois, by Schmidt 1953). Rana areolata circulosa, Davis & Rice 1883a: 28. Rana aerolata circulosa, Peters 1942:182. Rana areolata capito nec Le Conte, Yarrow 1882a:178. Rana capito nec Le Conte, S. Garman 1884:41. Rana areolata, H. Garman 1892:319-20. Diagnosis.—A large Rana (largest Llli- nois specimen 109.8 mm. from snout to vent), fig. 80, with dorsolateral folds; con- spicuously mottled upper jaws; prominent hump at the middle of the back; tympanum always smaller than eye; large head; conical snout; and milky white groundcolor visible at the margins of the many closely crowded, round, black spots. Table 24 -—Geographic variation in proportionate leg length in three Illinois samples of Rana areolata. Figures in parentheses are numbers of specimens. The groundcolor ist cA Variation.—The female gopher frog ay-— erages larger than the male and possesses heavy glandular ridges under the tympa- nums. The male has a pair of saclike vocal pouches on the sides of the head and enlarged thumbs. Ten newly transformed specimens, rang- — ing from 22.5 to 24.5 mm. in snout-vent — length, differ from sexually mature adults by their proportionately larger heads, shorter : legs, more distinctly spotted dorsums, and less distinctly barred legs. Head length in 10 — juveniles ranges from 39.6 to 41.0, averag-— ing 40.2, per cent of the body length, whereas ~ in 50 frogs over 57 mm. in snout-vent length — it ranges from 30.0 to 37.1, averaging 33.3, per cent. Tibia length for the 10 juveniles ranges from 42.5 to 47.5, averaging 45.1, per cent of the body length, whereas in the 50 — adult specimens it ranges from 34.9 to 53.9, — averaging 48.8, per cent. : Data provided by three samples of adults — suggest a slight reduction in proportional © ry: a Epcar-Cotes- LAWRENCE Winwiaiee CUMBERLAND To Bonp Counry (20) Coan taiepnric Counties (20) Counties (11) ] a Range Mean Range | Mean Range Mean Snout-vent length (mm.).........-. 65.9-109.8)iew. .-. 76 OAM occas 57.2-106.3}.1 aa Head length as percentage of body lenetiion een wine iiorc fate 30.0-35.5 33.5 |31.0-37.5 33.1 |31.0-37.1 33.2 Femur length as percentage of body lensthiteacc sotto epee ele 39.6-49.8 44.3 |43.9-47.3 45.4 |35.3-43.6 38.3 Tibia length as percentage of body lenethincee corer ities viiiie acs 46.7-53.9 50.7 |48.2-52.0 50.3 |34.9-49.9 | 46.2 November, 1961 leg length toward the south, table 24. Other trends in geographic variation are not evi- dent. Habits.—Except for a brief period in spring when it is mating, the gopher frog remains hidden in abandoned crayfish holes and is seldom encountered above ground. The distribution of this species is apparently correlated with the hardpan, clay soils that are extensive in southern Illinois. Outlier prairies, wet pastures, and golf courses are particularly favorable habitats. During sum- mer and fall an adult can sometimes be found by investigating a large-bore crayfish hole that has a bare platform to one side of the entrance. The frog usually may be seen an inch or so below the surface, but when disturbed it backs down to the bottom of the burrow, where it wedges its body against the sides of the hole. The bottom of the bur- row usually contains fecal matter, including | i (uh Fig. 81.—Distribution of Rana areolata. Hatching indicates the presumed range of the subspecies circulosa in Illinois; solid circles indicate localities represented by specimens examined during this study. The lower map depicts the total range of the species in the a States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 95 crayfish remains. The depth of the hole ay- erages a little Jess than a yard. The breeding season of this frog varies somewhat with temperature and the distri- bution of spring rains; choruses have been heard from early March to mid-April. The call of the male is a prolonged bass snore with remarkable carrying power. The pvye- ferred breeding sites are flooded fields, farm ponds, and small lakes in pastures or on golf courses; at the peak of the season several hundred adults may occupy a single pond. Approximately 5,000 eggs are deposited by each female in shallow water as large, sub- merged masses. Hatching probably requires several days. The larvae transform in Illi- nois in late June and early July. Illinois Distribution—The gopher frog, or northern crayfish frog, is a characteristic animal of the outlier prairies of the south- ern half of Illinois, fig. 81, and it is much more abundant than the map indicates. In Illinois the range of the species terminates abruptly at the southern edge of the Shelby- ville Moraine; records for adjacent Indiana and Iowa extend slightly farther north. Rana catesbeiana Shaw Bullfrog Rana catesbciana Shaw 1802:30 (type locality: South Carolina; revised to vicinity of Charleston by Schmidt 1953); Shelford 1913:171. Rana catesbiana, Yarrow 1882a:184. Rana catesbeana, Hankinson 1915:294. Rana pipiens nec Schreber, Brendel 1857:254. ?Rana clamitans nec Latreille, Hankinson 1910: 25: Diagnosis.—A large Rana (largest Illi- nois specimen 154 mm. from snout to vent), fig. 82, lacking dorsolateral folds but pos- sessing well-developed tympanic folds; web- bing extending to toe tips; olive, green, or brown dorsum, with dots or obscure blotches but not with discrete dark spots; median gular vocal pouch in the male; and tym- panum larger than eye in adults of both sexes. Variation.—The male bullfrog differs from the female in being smaller in size and in having greatly enlarged tympanums, swollen thumbs, yellow throat, and two openings inside the mouth which lead to the vocal pouch. Virtually all juveniles less than 60 mm. in snout-vent length are olive, with small, 96 Intinois NatrurAL History SurvEY BULLETIN black, evenly distributed dots over the dor- sum. The dots are retained in occasional adults but they are usually brown rather than black. In most large subadults the dark dots are lost and the pattern, if present at all, consists of mottling or light, obscure blotches on a darker groundcolor. Sexual dimorphism is not evident in juveniles. The range of individual variation in pat- tern and proportions in a single sample usu- Fig. 82.—An adult Rana catesbeiana from Coles County, Illinois. Vol. 28, Art. 1 Half of the specimens available are reticu- lated or spotted ventrally; the highest fre- quency of such frogs occurs in western IIli- nois and the lowest frequency in eastern IIli- nois. This character is probably of little significance. Habits.—The bullfrog inhabits almost any type of permanent water, such as lake, pond, river, and creek. Adults are rather solitary, each frog occupying part of the svoue fe i i i a SIT AS Ir i al i ws ice Me ee nicht Sty The color range is usually olive or brown over the body, with some green on the upper jaw. ally exceeds any geographic variation dis- cernible. The mean tibia length in samples of 12 to 20 specimens from Shawnee Hills, south-central Illinois, and north-central IIli- nois varies from 48.5 to 49.3 per cent of the body length, exhibiting a difference of less than 1.0 per cent. A series of 20 specimens from western Illinois differs only slightly, averaging 47.5 per cent. The lower mean, which is of doubtful significance, is due to nine specimens, from Adams and Hancock counties, that are somewhat shorter-legged. stream or pond to the exclusion of other adults. They are wary and are difficult to approach during the day but rather easy to catch at night. When disturbed they retreat to deeper water with a series of long leaps and considerable splashing. The bullfrog is of some importance as food for man. How- ever, in parts of Illinois the gopher frog is eaten by more people. The bullfrog is vora- cious, eating almost any animal it can swal- low. Although a great many kinds of ani- mals have been found in bullfrog stomachs, — November, 1961 crustaceans and insects probably make up the bulk of the diet. Breeding in the bullfrog occurs from late April until August. The call of the male is a deep bass, consisting of two slurred sylla- bles. The song, which has great carrying power, has been characterized as “jug-o’- rum” and “br-wum.” Each female lays sev- eral thousand eggs in a huge surface mass, often a yard across. Hatching occurs in less than a week. Although tadpoles grow rap- idly, they presumably overwinter, develop- ing legs the following spring, and metamor- phose in July and August of their second season. The larvae may attain a length of more than 6 inches. Illinois Distribution—The bullfrog is common in all parts of Illinois, fig. 83. Although undocumented by specimens, published records for the following locali- Fig. 83.—Distribution of Rana catesheiana. The species occurs throughout Illinois. Solid circles indicate localities represented by speci- mens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 97 ties are believed valid and are indicated on the distribution map by hollow symbols: Cook County: Evanston (Schmidt & Necker 1935); Willow Springs (Schmidt 1929); Du Pace County: Naperville (Necker 1939c); Jackson County: Car- bondale (Cagle 1942a); 2 mi. S Elkville (Burt & Burt 1929) ; Lakz County: Wau- kegan (Schmidt 1929); McHenry Coun- TY: McHenry (Necker 1939c) ; Macoupin County: Standard City (Owens 1941) ; Mapison County: opposite St. Louis (Hurter 1893); Morcan County: Mere- dosia (Weed 1923); Pror1a County: Pe- oria (H. Garman 1892); UNion County: Anna (H. Garman 1892); 7 mi. S Anna (Burt & Burt 1929); WapasH County: Mount Carmel (Yarrow 1882a); Wasu- INGTON County: 7 mi. SE Beaucoup, Nashville (Burt & Burt 1929). Rana clamitans melanota (Rafinesjue) Green Frog Ranaria melanota Rafinesque 1820:5 (type locality: Lake Champlain, New York). Rana clamitans melanota, Mecham 1954:1, 4, Sh Rana clamata, Kennicott 1855:593. Rana clamitans, Yarrow 1882a:183. Diagnosis——A medium-sized to large Rana (largest Illinois specimen 95 mm. from snout to vent), fig. 84, with prominent dor- solateral folds that extend only to the mid- dle of the back; webbing extending almost to the toe tips; back olive, brown, or green; dorsum plain, or with obscure dark spots which are not light margined; dark spots or reticulations usually on chin, breast, and undersides of legs; sexual dimorphism (in color and size of tympanum) pronounced. Variation—In Rana clamitans melanota the male differs from the female in having a larger tympanum, swollen thumbs, and stouter forelegs. In most of Illinois, it has a bright green upper jaw and yellow throat ; the population in extreme southern Illinois is exceptional in that color dimorphism is less pronounced. The female is said to be larger than the male; this size difference is not obvious in the series at hand, although the largest specimen known is a female. Ontogenetic variation is not striking, but the ventral markings are somewhat bolder in subadults than in large frogs. In most of Illinois geographic variation in the green frog is rather slight. A weak 98 Ittrinoris NaruraAL History SuRvEY BULLETIN Vol. 28, Art. 1 eet 6) es | ata Saxo e Eg aes nS eae Ggecse ; Kase a rise Sj Fig. 84.—An adult Rana clamitans melanota from Vermilion County, Illinois. The ground- color is green, olive, or brown. Males usually have green upper jaws and yellow throats. Table 25.—Geographic variation in Illinois Rana clamitans. Figures in parentheses are numbers of specimens. ExTREME SouTHERN Itirnots (18) EAsTERN ILuinots (11) WESTERN Itxinois (13) NorTHERN Itiinots (39) CHARACTERISTIC Range | Mean | Range | Mean | Range | Mean Range | Mean ———$———— | a a el Femur length as per- centage of body : lege eee. Se. 43.2-53.9}| 48.3 |44.2-51.2) 48.3 |45.2-54.2} 49.9 |46.1-53.3] 48.5 Tibia length as per- centage of body lenethice s.iucsioe\>/. 45.3-54.5| 50.2 |46.6-54.5| 50.4 |47.0-54.3| 52.1 /46.3-54.1) 51.2 Snout-vent length (mm.), maximum. 95 Olsestaseee Vai) eee BeBe SA. Ovo R ses 79.0|; > an Per Centor | Per CenT oF Per CENT OF Per CENT OF SPECIMENS | SPECIMENS SPECIMENS SPECIMENS With belly unmarked 69.0 | 84.5 82.0 33.5 November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 99 trend toward greater average size and bet- ter-developed dorsal spotting in the northern samples is apparent. In the samples from the southwestern tip of the state the indi- viduals are of smaller average size; fre- “quent specimens are without dorsal spot- ting; and many have dark markings on the belly, some being boldly marbled with black. The males tend to have dusky upper jaws and throats rather than the green and yel- low of more northern males. The south- tern samples are assumed to represent | an intergrade population, R. c. melanota X clamitans. The variation is illustrated by four samples, table 25. | Habits.—In northern Illinois the green | frog occurs in a variety of aquatic habitats, but in the central and southern counties it appears to be restricted to clear streams in the vicinity of rock outcrops. It is often seen on a bank above water and when disturbed it can reach the safety of deep water with a single leap. A startled green frog some- times emits a high-pitched squawk at the in- stant it jumps. Like the bullfrog, this spe- cies is somewhat solitary in habits, but the presumed home range of one individual is smaller in area than that of the bullfrog. The green frog probably eats almost any invertebrate and small vertebrate animal on occasion, but the chief items in its diet are arthropods, mollusks, and annelids. In Illinois breeding of the green frog ap- parently occurs throughout the summer, as singing may be heard from May until Sep- tember. The call of the male consists of two /or three well-spaced, explosive notes, each -of which closely resembles the plucking of | the bass string on a banjo. The female de- | posits several thousand eggs in shallow sur- |face masses that are similar to those of the bullfrog, but each mass is less in diameter. | Hatching occurs in a few days. The tad- ‘poles, which resemble the bullfrog larvae, ‘overwinter and transform throughout the Baummer of the second season. | Illinois Distribution——The Illinois dis- tribution, fig. 85, of the green frog, which is jabundant in most of eastern North Amer- jica, is puzzling. The species is common in ‘\ponds, lakes, and streams throughout the ‘northern fourth of the state, but it becomes jincreasingly sporadic in occurrence to the ‘south. In central and southern Illinois it is absent from the Grand Prairie and the Southern Division, but it occurs along both — the extreme eastern and western edges of the state in the immediate vicinity of rock outcrops. In the Shawnee Hills of southern Illinois it is common in rocky, clear streams. The record for Charleston (Hankinson 1910) is almost certainly based on a mis- identified specimen of the bullfrog. Intergradation of R. c. melanota with R. c. clamitans occurs along the Mississippi River floodplain of Jackson, Union, Alexan- der, and possibly Johnson counties. The swampy habitat of the intergrade popula- tion is quite different from the preferred habitat of the northern R. c. melanota and resembles that of R. c. clamitans. Although undocumented by _ specimens, published records for the following locali- ties are believed valid and are indicated on ae > Fig. 85.—Distribution of Rana clamitans. Vertical hatching indicates the presumed range of the subspecies melanota in Illinois; cross- hatching, the presumed range of the melanota X clamitans intergrades; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. 100 the distribution map by hollow symbols: CHAMPAIGN CouNTy: Champaign (H. Garman 1892); Cook County: Chicago (Schmidt & Necker 1935) ; Du Pace Coun- ty: Naperville (Schmidt & Necker 1935) ; Jackson County: 4 mi. S Carbondale (Burt & Burt 1929); Kane County: Ba- tavia, West Dundee (Stille & Edgren 1948) ; Lake County: Fox Lake (Schmidt & Necker 1935) ; McHENrRy County: Mc- Henry, Richmond (Schmidt & Necker 1935); Union County: 7 mi. § Anna (Burt & Burt 1929) ; Witt County: Hick- ory Creek (Necker 1939c): Marley, New Lenox (Schmidt & Necker 1935); Romeo- ville (Necker 1939c). Rana palustris Le Conte Pickerel Frog Rana palustris Le Conte 1825:282 (type local- ity: not given; suggested as vicinity of Philadelphia, Pennsylvania, by Schmidt 1953); Brendel 1857:254. Diagnosis.—A small to medium-sized Rana (largest Illinois specimen 69.2 mm. I~tinois NarurAL History SurvEY BULLETIN Vol. 28, Art. 1 from snout to vent), fig. 86, with distinct, square or rectangular, brown or _ black blotches arranged in two more or less regu- lar series between the dorsolateral folds; dorsolateral folds yellow, extending to the hip region, and approximately half the width of the dorsal blotches; groundcolor gray or tan; concealed surfaces of hind legs and often the belly with a wash of bright yellow. Variation.—The male pickerel frog has enlarged thumbs, each of which bears a small pad on its inner surface. According to Pope (19444), the male is usually darker, larger, and more fully webbed between the toes than the female. In our series, how- ever, the female averages larger, and Walker (1946) noted that females are larger in Ohio specimens. No small specimens are available for study. Young frogs observed in the field, however, seemed to differ from adults in their proportionately larger heads and smaller legs. Two races of the pickerel frog, differing in pattern details and proportions, are pres- ent in Illinois: an unnamed race, which oc- Fig. 86.—An adult Rana palustris from Monroe County, Illinois. The groundcolor is yellow, tan, or light gray; the square or quadrangular blotches are chestnut or dark brown. i i ? iy Wy November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 101 Table 26.—Geographic variation in Illinois Rana palustris. Figures in parentheses are numbers of specimens. Monroe County (17) Prke, ADAms, AND GREENE Counttes (23) NorTHERN I_uinors (11) ALEXANDER- Union CHARACTERISTIC Counties (8) Range Mean Range Snout-vent length. . |28.2-57.0]........ 33.0-64.8 Head length as per- centage of body Levive(2 Ss Se eee BoE = 4s Se OSS 29238.8 Tibia length as per- centage of body Wenerthitisis sste ce os SAO IIASe Soe) SO. 262.5 Blotches between dermal folds...... 6-15 9.9 11-17 Mean Mean Range Range | Mean Riedel oT) teas ate SATS 1 fel | 36.8 |32.1-38.6} 36.1 /33.0-38.4] 36.0 56.9 |54.2-62.9| 57.6 |55.6-63.5| 58.7 13.8 9-21 WSS 6-17 ey Per CENT OF Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS SPECIMENS With snout spot.... 120 77.0 84.3 82.0 With mottled chin. . 88.0 70.6 21.9 9.0 With mottling on underside of legs... 100.0 53.0 Wipe 0 curs in Alexander and Union counties and occupies an unexpected habitat for the spe- cies, and the typical race, which occurs spo- radically along the rock bluffs of the Mis- sissippi River northward to the northern fifth of the state, where it is rather general in occurrence. The two races differ slightly in proportions and markedly in pattern, table Habits—Throughout most of its range this frog is limited in distribution by its in- tolerance of bodies of water that are both warm and sluggish. In northern Illinois, for example, the species occurs around ponds, creeks, and marshes, and in central Illinois it is found only in cold springs or rocky, fast-running streams. In western I ]linois the species exhibits a fondness for caves in which there are permanent streams. However, in southern Illinois a race of the pickerel frog occurs in the relatively warm waters of floodplain swamps. Pickerel frogs are alert and powerful jumpers and accordingly dif- ficult to collect in marsh or stream-edge vegetation. The pickerel frog is reputed to have a skin secretion that is toxic or at least distasteful to many other animals, but ex- perimental evidence is needed to substanti- ate the report. Its food consists probably of arthropods and mollusks. The pickerel frog presumably spawns in the clear, quiet water of bogs, lakes, and ox-bows. The song of the male is a short, low-pitched snore with little carrying power. The female lays 1,000 to 2,000 eggs in com- pact globular masses. The eggs hatch in about 2 weeks. I have not seen tadpoles in Illinois. Newly transformed adults are found the last of June. Iliinois Distribution.—The peculiar dis- tributional pattern of this species, fig. 87, has been noted above. The range to some extent parallels that of R. clamitans, but the pickerel frog seems even less tolerant of con- ditions in the central prairie region. Al- though records are available from west-cen- tral Indiana, the Illinois range of the spe- cies is probably little more extensive than the localities on the map indicate. There is some possibility, however, that it may be found in the dissected canyons of La Salle County and in the rocky streams of extreme eastern Clark and Vermilion counties. Although undocumented by _ specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Kane County: Batavia (Stille & Edgren 1948); Sr. Crarr County: Bluff Lake (Hurter 1893). 102 oa tl . ig ‘all il Te | Fig. 87.—Distribution of Rana palustris. Hatching indicates the presumed range of the species in Illinois; solid circles indicate local- ities represented by specimens examined dur- ing this study; open circles, localities repre- sented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Rana pipiens Schreber Leopard Frog Opinion is about equally divided among current herpetologists as to whether Rana pipiens consists of subspecies distinct enough to warrant taxonomic recognition. Inasmuch as this is one of the most famous problems in herpetological taxonomy, a solution sat- isfactory to everyone will appear only when series of specimens from over all of North America are studied in monographic fash- sion. In spite of the difficulty in recognizing races in some parts of the continent, there are certain geographical areas in which the distinctness of subspecies is unavoidable. Such is the case in Illinois and adjacent states, and it is as difficult to lump the two Illinois populations of the leopard frog as Intrnors NatTuRAL History SuRVEY BULLETIN Vol. 28, Art. I it seems to be for eastern and southwestern | investigators to recognize more than one form of this frog. Variation data for the Illinois populations are presented in the hope that they may contribute to a final un- — derstanding of the pipiens problem. Unfortunately, the question of names for — the population adds still more confusion, and — usage of pipiens and sphenocephala as sub- specific names for the two Illinois popula- tions is accordingly tentative. The names in- volved in eastern North America are pipiens (1782, type locality: New York), brachy- cephala (1889, type locality; Yellowstone Mn ED Sey River), sphenocephala (1886, type locality: — St. John’s River, Florida), and berlandieri (1854, type locality: South Texas). Provi- sional assignment of the subspecific name — pipiens to the northern Illinois frogs and — the subspecific name sphenocephala to the southern Illinois frogs assumes that the — populations berlandieri and sphenocephala are distinct taxonomically. Otherwise, the — earlier name, berlandieri, would supersede — sphenocephala for the southern population. Assignment of the name pipiens to the north- ern population also assumes that the names — pipiens and brachycephala refer to the same population, or that pipiens Schreber is an intergrade between the northern, large spot- ted frog that Cope described as brachy- cephala and the southern, small spotted frog that the same author described as spheno- cephala. This assumption (that pipiens is an intergrade between the northern and southern races) is a strong possibility, al- though Schreber’s colored plate represents a fairly typical specimen of the northern frog; and, if correct, the name pipiens, which has — priority over both sphenocephala and brachy- — % 3 : * ; ‘ ij 2 ot he : cephala, could be assigned to either of these — races. Obviously, it would be preferable to — restrict pipiens to the northern form, in view — of the long usage of the name in experi- mental biology for frogs from the northern population. In brief, the history of the pipiens inves- ‘ Cope (1889) as- tigations is as follows. signed sphenocephala, brachycephala, and virescens to R. virescens (equals pipiens) as— subspecies. Dickerson (1906) and_ the Wrights (1933 to date) recognized pipiens and sphenocephala as races of R. pipiens, but they did not accept brachycephala. Bou- lenger (1920) regarded R. pipiens as a mono- typic species. Kauffeld (1936) resurrected : November, 1961 brachycephala and regarded it, as well as pipiens and sphenocephala, as full species. Mittleman & Gier (1942) resurrected ber- landieri for the southwestern leopard frogs, but evaded the question of the validity of other races. Moore (1944), who studied the problem most intensively, concluded that no subspecies were recognizable. Cope (1889) and Kauffeld (1936) both utilized proportionate head length as a cri- terion for separating the three races which they recognized, and Dickerson (1906) and the Wrights (1933) used the same charac- ter for distinguishing pipiens from spheno- cephala. rapido & Clausen (1938) and Grant (1941) criticized the use of this char- acter because Quebec specimens under study by them failed to agree with the proportions Kauffeld (1936) recorded for brachycephala (the population presumably occurring in Quebec). Moore (1944) tested this char- acter with large series and reported no sig- nificant differences in head _ proportions. These seemingly diametrically opposite views are easily explained if samples of similar-sized specimens are compared. The amount of ontogenetic variation in propor- tionate head length in one population exceeds the amount of variation displayed by adults of the two different populations. The differ- ence in means between samples of similar- sized individuals from the two populations is slight. The northern population, brachy- cephala of Kauffeld or pipiens as here un- derstood, attains a larger maximum and ay- erage size, however, and, if small samples of fully adult specimens of northern and southern frogs are compared, the difference between the means is magnified simply be- cause the northern form is a larger frog. It is likely that Cope and Kauffeld believed the head-length character was diagnostic for this reason. Actually, it has only limited diagnostic value, but it is discernible. The ratios displayed by 64 specimens of R. f. pipiens from northern Illinois and 60 speci- mens of R. p. sphenocephala from southern Illinois are shown by the graph, fig. 88. Length of snout, as well as proportionate head length, has been used as a subspecific character by those authors who recognize subspecies in R. pipiens. In the Illinois series the southern frogs appear to have longer, more acuminate snouts, but I am unable to find any mensurable difference. It appears that the position of the eyes and the more SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 103 prominent dark vitta of southern specimens creates the illusion of longer snouts. Leg length has similarly been used as a subspecific character and it is usually ex- pressed as the point reached by the heels when the legs are carried alongside the body. Because of the difficulty of manipulating limbs of preserved specimens, tibia/body ratios have been computed in lieu of the leg- body relationship. Moore (1944) investi- Rana pipiens sphenocephala Rana pipiens pipiens HEAD LENGTH / BODY LENGTH, PER CENT 40 50 60 70 80 SNOUT - VENT LENGTH, MILLIMETERS Fig. 88.—Head/body length ratios for 60 specimens of Rana pipiens sphenocephala and 64 specimens of Rana pipiens pipiens. The di- agonal lines connect means of each size class; the vertical lines represent variational ranges exhibited by each size class. gated both ratios and found only a slight tendency toward longer legs in those frogs from southeastern United States. Tibia/ body ratios for 270 Illinois specimens reveal no indication of clinal variation in this char- acter. In combined samples of R. p. spheno- cephala the tibia averages 56.8 per cent of the body length, and in combined samples of R. p. pipiens it averages 56.9 per cent. The degree of webbing, amount of dark mottling on the rear of the thighs, nature of the tibial bars, width of the dorsolateral folds, and presence of secondary dorsal ridges are of limited value, although none is constant enough to be a good diagnostic character. The presence of a light tympanic spot, a character frequently stated to be diagnostic of R. p. sphenocephala, does not coincide geographically with the other subspecific characters of R. p. sphenocephala in Illinois. Instead, it occurs in all Illinois populations except those in the northern third of the state. 104 The remaining characters used by various authors (nature of vocal sacs in breeding males, size of spots and prominence of light margins, and groundcolor) and the presence of a dark snout spot are reliable; they in- dicate that two subspecies are valid. Rana pipiens pipiens Schreber Northern Leopard Frog Rana pipiens Schreber 1782:185, pl. 4 (type locality: New York; revised to White Plains, New York, by Schmidt 1953); H. Garman 1890:188-9 (part). Rana pipiens pipiens, Pope 1944b:132-42. Rana halecina, Kennicott 1855:593. Rana halecina halecina, Davis & Rice 1¢83a: 28 (part). Rana halecina berlandieri nec Baird, ? Yarrow 1882a:181. Rana virescens, H. Garman 1889:134. Rana_ virescens virescens, Cope 1889:403 (part). Rana _ virescens brachycephala Cope 1889: 403-6 (type locality: Yellowstone River). Rana pipiens brachycephala, Wright & Wright 1949:511. Rana_ utricularia, (part). Rana pipiens burnsi, Wright & Wright 1933: 178-9. Rana pipiens sphenocephala nec Cope, Wright & Wright 1949:496-7 (part). H. Garman 1892:321-2 Diagnosis.—A medium to large Rana (largest Illinois specimen 96.2 mm. from snout to vent), fig. 89, with large subround or elongate dark spots on a green, tan, or brown background; venter white or off- white; a pair of prominently widened dorso- lateral folds extending the length of the back; secondary ridges often present between dorsolateral folds; the breeding male with a pair of lateral vocal pouches that do not pro- ject posteriorly; a large dark spot on top of snout (in 87 per cent of specimens) ; dorsal spots distinctly margined with light and averaging larger than eye (in 78 per cent of specimens) ; no discrete light spot in center of tympanum; postfemoral reticulum heavy; tibia boldly barred with dark. Variation.—The male leopard frog is smaller than the female and differs also in having enlarged thumbs and stouter fore legs. During the breeding season, the skin is loose between the angle of the jaws and the shoulder region, indicating the position of the internal vocal sacs of the male frog. Juveniles have proportionately longer, narrower heads than adults and weaker Ittinors NaturRAL History SURVEY BULLETIN P) Vol. 28, Art. 1” bars across the legs. The head-length rela- _ tionship is graphed in fig. 88. Several trends of unknown importance can be discerned by comparing series of speci- mens from northeastern Illinois with those — from northwestern Illinois. Specimens from the northeast tend to possess a darker groundcolor, more conspicuous light margins around spots, larger spots, and more promi- nent secondary dermal ridges between the dorsolateral folds. In Illinois, the most striking geographic — variation in R. pipiens pipiens occurs from — north to south, inasmuch as pipiens inter- grades with R. p. sphenocephala in the cen-— tral part of the state. Two intergrade sam- ples, one from Coles County and the other from Mason and Morgan counties, differ from northern Illinois leopard frogs in the smaller frequency of individuals with snout spots, the smaller average size of the dorsal spots, the occasional presence of males with external vocal sacs, and the usual presence — of a light tympanic spot. These characteris-_ tics for four typical pipiens samples and two intergrade samples are shown in table 27. Habits——The leopard frog occurs in abundance in the vicinity of streams, ponds, or lakes and it is frequently encountered in fields well away from permanent water. It — is an excellent jumper and is so alert that it is dificult to capture unless it is stalked — at night with a flashlight. The captured frog often squawks and usually emits a copious quantity of urine. When seized by a predator, such as a snake, the leopard frog — may scream. Juveniles of this species some- times inhabit puddles—water-filled automo- — bile tracks—in little-used dirt roads. The — heads of several young frogs may be seen protruding from the water by any person — approaching such a puddle. As soon as the — young frogs sense danger, they quickly leave — the water for the greater protection of sur- — rounding vegetation. ; Breeding in the northern leopard frog oc-_ curs from mid-March to May. The breed-— ing sites are ponds, lakes, sloughs, or semi- 3 permanently flooded fields. The call of the — male has been characterized as “coaxing” — and can be simulated by rubbing a thumb over an inflated balloon. Each female de-— posits 3,000 to 5,000 eggs in compact, slightly flattened, submerged spheres, which are usu- ally 3 to 6 inches across. Hatching presum- ably requires approximately a week, and November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 105 Fig. 89.—An adult Rana pipiens pipiens from Porter County, Indiana. The groundcolor may be green, gray, or tan; the spots are usually brown. Note spot on snout. Hunt Conant.) (Photo by Isabelle Table 27.—Geoégraphie variation in Illinois Rana pipiens pipiens and R. p. pipiens X sphenocephala intergrades. Figures in parentheses are numbers of specimens. CHARACTERISTIC With snout spot (per cent of specimens)... |With average dorsal | spot smaller than eye | (per cent of speci- iS) ee /With external vocal sac (per cent of males) |Snout-vent length |} (mm.), maximum.... Nortu- EASTERN ILLINoIs (18) 89.0 77.8 NortuH- WESTERN ILLINOIS (23) 78.0 88.9 HeENDER- SON- WARREN CounrTIES (14) CHAM- PAIGN- VERMILION CouNTIES (9) Co.Les County (20) Mason- Morcan CounrTIES (24) 106 transformation occurs from June until Aug- ust. Illinois Distribution.—R. p. pipiens is common around almost all types of water throughout the northern half of Illinois, fig. 90. Intergradation with R. p. spheno- Fig. 90.—Distribution of Rana pipiens. Ver- tical hatching indicates the presumed range of the subspecies pipiens; horizontal hatching, the presumed range of the subspecies spheno- cephala; crosshatching, the area of intergrad- ation between the two subspecies; solid circles indicate localities represented by specimens examined during this study; open circles, local- ities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. cephala occurs across the central part of the state. The intergrading area is relatively narrow in eastern Illinois, wider along the Mississippi River, and also wider in the Illinois River valley, where intermediates are known from Jersey to Mason County. Although undocumented by _ specimens, published records for the following locali- ties are believed valid; most are indicated on the distribution map by hollow symbols: ILtinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. I Cook County: Carle Woods (Necker 1939-); Chicago Ridge (Schmidt & Necker 1935); Deer Grove, Evanston (Necker 1939c); Homewood, Lambert, Wolf Lake (Schmidt & Necker 1935); Du Pace County: Downers Grove, Glen Ellyn, Lisle, Naperville (Schmidt & Necker 1935); GruNnpy County: Coal City, Pequot (Necker 1939c); Hrnry County: (Hj) Garman 1892) ; KANE County: West Dun- dee (Stille & Edgren 1948); KANKAKEE County: Aroma ‘Township, Pembroke Township (Schmidt & Necker 1935) ; Knox County: 214 mi. E Galesburg (Adcock 1922); Lake County: Beach, Fox Lake; Highland Park (Schmidt & Necker 1935); Waukegan (Necker 1939c); McHenry County: McHenry, Richmond (Schmidt & Necker 1935); McLean County: Normal (H. Garman 1892) ; Octe County: Grand Detour (Yarrow 1882a) ; PEorta County: Peoria (H. Garman 1892); STEPHENSON County: Freeport (H. Garman 1892). Rana pipiens sphenocephala Cope Southern Leopard Frog Rana halecina sphenocephala Cope 1886:517 (type locality: near St. John’s River, Florida). Rana sphenocephala, Blanchard 19245:535. Rana pipiens sphenocephala, Wright & Wright 1949:496-7 (part). Rana halecina halecina, Yarrow 1882a:179-80. Rana halecina, Boulenger 1920:433-45 (part). Rana_ virescens virescens, Cope 1889:403 (part). Rana virescens brachycephala nec Cope, Cope 1889:405-6 (part). . Rana pipiens, H. Gatman 1890:188-9 (part), Rana pipiens pipiens nec Schreber, P. W. Smith 1947:32. Rana _utricularia, (?part). H. Garman 1892:321-2 Diagnosis.—A subspecies of Rana pipiens (largest Illinois specimen 79.4 mm. from snout to vent), fig. 91, differing from R. p. pipiens in being smaller, in lacking a dark snout spot, and in having the following ad- ditional characters: a pair of external vocal sacs which project posteriorly in the breed- ing male; dorsal spots averaging smaller than eye diameter (in 76 per cent of speci- mens); dorsal spots not distinctly margined with light; groundcolor light tan, gray-green, or light brown; usually a discrete light spot in center of tympanum; tibial bars frequent ly interrupted; less distinct postfemoral re- ye y s November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 107 Fig. 91—An adult Rana pipiens sphenocephala from Union County, Illinois. The ground- color is usually gray or tan, rarely green; the spots are brown. ticulum; narrower and lighter colored dor- solateral folds; narrower and lighter col- ored maxillary ridge; and sharper-appear- ing snout. Variation.—Sexual variation inks ps sphenocephala is similar to that in R. 9. pipiens, although more pronounced because of the pouchlike vocal vesicles, the statement by Liu (1935) that all pipiens subspecies have internal sacs notwithstanding. Ontogenetic variation in the southern leop- ard frog is similar to that in the northern Table 28.—Geoégraphic variation in Illinois Rana pipiens sphenocephala. Figures in paren- theses are numbers cf specimens. CHARACTERISTIC Snout-vent length (mm.), maximum..... Spots between dorsolateral folds........ PURGE SHOE’. sons cesta sess MeREn tYMpAnic SPOt.... ccs. 0.eerecces eee SHAWNEE SouTH-CENTRAL [eiemors (20) Hixts (20) Itiinors (20) Range Mean Range Mean Range Mean OA eee GOON Serato ceiee BOSON ee 5-20 12.8 8-30 17.3 7-23 14.5 Per CENT OF SPECIMENS Per CENT OF SPECIMENS 15 85 Per CENT OF SPECIMENS 10 95 108 subspecies. The head-length/body-length re- lationships are summarized in fig. 88. Individual variation in a series of R. p. sphenocephala from one locality exceeds geo- graphic variation (the difference between series) displayed within Illinois. The only trend discerned in this subspecies is a ten- dency for individuals from the Mississippi and Ohio River floodplains at the southern tip of Illinois to have fewer dorsal spots. These frogs are usually brassy in appear- ance, and a few individuals have been seen that had no dorsal spots. Such individuals are remarkably similar to wood frogs. Va- riation in the more salient features of three samples of R. p. sphenocephala is summa- rized in table 28. Habits.—The southern leopard frog is similar to the northern race in habits and habitat, and most of the remarks concern- ing behavior of R. p. pipiens apply as well to this form. The breeding season for spheno- cephala is known to be earlier, and singing begins in early March and extends into April. There is some likelihood that devel- opment is faster in sphenocephala; trans- forming frogs can be found in June and early July. Illinois Distribution—The — southern leopard frog is abundant throughout the southern half of Illinois, fig. 90. Inter- gradation with R. p. pipiens occurs in a rather narrow zone in eastern Illinois at about the Shelbyville Moraine. The inter- grading area widens in western Illinois, but it usually does not exceed a hundred miles in width. Although undocumented by specimens, published records for the following locali- ties are believed valid and are indicated on the distribution map by hollow symbols: Macouptn County: Standard City (Owens 1941) ; Putaski County: Villa Ridge (H. Garman 1892) ; RicHLAND County: Olney (Cope 1889); Unton County: Anna (H. Garman 1892); 2 mi. N Anna (Burt & Burt 1929) ; WasHINGTON County: (Yar- row 18822). Rana sylvatica Le Conte The wood frog is transcontinental in northern North America. Several allied populations of northern Europe and Asia be- long to the same complex but are currently considered to be specifically distinct. The North American wood frog has been gener- Ittinois Natrurat History SurRvVEY BULLETIN Vol. 28, Art. 1 ally regarded as consisting of three subspe-_ cies; the distributional limits and the diag- nostic characters, until quite recently, have — been vaguely defined in the herpetological — literature. The species has, however, just received an intensive and thorough revision by Martof & Humphries (1959), who sug gest that the named subspecies be dropped. “t Their analysis of geographic variation in the | + species is excellent and objective ; their taxo- — nomic recommendation, in my opinion, is prompted by their personal attitude toward : subspecies. Inasmuch as their data can bell interpreted as suggesting that races are rec- — ognizable, subspecific names are provision- — ally retained for the two types of wood frogs represented in Illinois. Som ae Zit, Sg ee a ae Rana sylvatica sylvatica Le Conte Eastern Wood Frog Rana sylvatica Le Conte 1825:282 (type lo- cality: not stated; designated as New York — City by Schmidt 1953); Shelford 1913:195, — 206, 243, 244, 256. 4 Rana sylvatica ‘sylvatica, Cagle 1941:9 (part). Rana silvatica, Brendel 1857:254. € Rana temporaria silvatica, Yarrow 1882a: 185 (part). Rana cantabrigensis nec Baird, Hay 1892a:586. Rana cantabrigensis cantabrigensis nec Baird, f Cope 1889:437. Rana_ sylvatica cantabrigensis nec Baird, Schmidt 1938a:379 (part). af Diagnosis.—A medium-sized Rana (larg- — est Illinois specimen 54.5 mm. from snout to vent), fig. 92, with prominent dorsolateral — folds; tympanum smaller than eye; two or three joints of fourth toe free of webbing; tan or rich red-brown groundcolor above, | with a conspicuous chestnut or black mark on a side of head; dark dash on shoul- vent length; breast plain white (64 per cent of specimens) ; dorsum immaculate or occa- tween dorsolateral folds; secondary ridges — between dorsolateral folds seldom present. Variation.—No average size difference in the sexes is evident in the Illinois series of - eastern wood frogs. The male possesses — swollen thumbs, each of which bears a smal pad on the inner surface, and somewhat stouter front legs; and the webbing between the toes of the hind feet is convex rather November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 109 Fig. 92.—An adult Rana sylvatica sylvatica from Clark County, Illinois. The groundcolor is tan or light red-brown; the mask through the face and dorsal flecks are chestnut or dark brown. than incised. In the breeding ponds male may be rich red-brown while the male may be almost black. Outside the breeding the fe- ponds individuals of both sexes are ordi- narily light in color, but the female is usu- ally the more brightly colored. Table 29.—Geosgraphic variation in [Jlinois Rana sylvatica sylvatica and R. s. sylvatica X cantabrigensis intergrades. Figures in parentheses are numbers of specimens. CHARACTERISTIC | Snout-vent length (mm.).............. | Head length as percentage of body a ae Tibia length as percentage of body length Femur length as percentage of body length ee With breast unmarked With dark interorbital bar............. SOUTHWESTERN Ivitnors (6) Range Mean 36.0-50.8 33.5-38.4| 36.0 58.3-63.0} 61.1 47.3-56.9| 51.4 East-CENTRAL Ittrnors (30) NorTHEASTERN Itttnots (17) Range Mean 34.8-54.5]........ SI S=S/21 33.9 51.4-61.8} 58.6 48.8-56.6| 52.9 Range Mean BOL 0249s Siepeen ae 29.9-36.7| 32.6 ape 54.0 50.5 ne ae Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS 100.0 78.0 120 83.0 0 24.0 110 Young specimens are slightly shorter legged, larger headed, and less brightly col- ored than adults. In Illinois the most noticeable trends in geographic variation are the proportion- ately greater head size and longer legs in samples from north to south. The limited data at hand thus conform in general with the findings of Schmidt (1938a) that there is a north-south cline in leg length in the wood frog. Although north-south clines are evident in the Illinois wood frogs, the data do not preclude the possibility that a north- ern and southern race are involved. Suzuki (1951) did not find a regular cline in tibial length in Wisconsin samples, and specimens at hand from Arkansas are no longer legged than specimens from southwestern Illinois. The population in northeastern Illinois is regarded as being composed of R. s. syl- vatica X cantabrigensis intergrades. The sample from this part of Illinois displays cantabrigensis characters in proportionate head length, tibial length, size, and ventral pattern but sylvatica characters in dorsal pattern and dorsal skin texture. This varia- tion is summarized in table 29. Habits.—The wood frog, which is usually solitary in habits, is restricted to relatively mesic forests in which there are permanent or semipermanent pools. It is usually not abundant even in optimum habitat and is often overlooked because its colors blend so well with fallen leaves. Individuals are most often seen when they call attention to them- selves by making a long, low leap. In spring and fall the wood frog may be aquatic, but it spends most of the summer well away from water. Its food consists of arthropods and mollusks. The short breeding season of the wood frog occurs in March. A pond may be sud- denly full of breeding individuals and a week or two later they may have completely disappeared. The call of the male consists of a series of five or six explosive clucking notes that have little carrying power. Each female lays 2,000 to 3,000 eggs, which soon become a submerged globular mass. Hatch- ing requires only a few days, and the larvae grow rapidly. The tadpole is distinctive be- cause of the labial formula of 34, fig. 53. Transformation takes place in May and June. Illinois Distribution.—The eastern wood frog is exceedingly sporadic in occurrence Iturinois NaTrurRAL History SurvEY BULLETIN Vol. 28, Art. 1 —— (ae || ¥ * SS SS. Cee eA ay SE 2S == a) ny Sas! Sees Pe Tae Ts = = = Let Sh Fig. 93.—Distribution of Rana sylvatica. — Vertical hatching indicates the presumed range of the subspecies sylvatica in Illinois; hori- zontal hatching, the presumed range of the — subspecies cantabrigensis; crosshatching, the — area of intergradation between the two sub- species; solid circles indicate localities rep- resented by specimens examined during this — study; the open circle indicates a locality rep- — resented by a published record believed to be — valid. The lower map depicts the total range of the species in the United States. [ even in forested parts of the state, fig. 93. £ It is moderately common in Coles County, © but attempts to find the species in some ad- jacent counties, which have seemingly suit- able habitats, have been unsuccessful. Once — a locality is found in which the species oc- ~ curs, it is usually possible to collect speci- mens on each subsequent visit. It is difficult — to ascertain if the number of wood frog populations has been appreciably reduced by drainage and destruction of forest or if this — frog was sporadic in occurrence in Illinois — even before such practices were begun. R. sylvatica is regarded as one of the animal — indicators of the beech-maple forest, al-— though most of the Illinois localities in November, 1961 SmiItH: AMPHIBIANS AND REPTILES OF ILLINOIS 111 which the species is known are west of this ecological zone. The wood frog populations throughout southern and most of eastern Il]linois are re- garded as typical R. s. sylvatica, the popu- lation in northeastern Illinois as sylvatica X cantabrigensis intergrades. ‘The central prairie region is apparently uninhabited by the species. Rana sylvatica cantabrigensis Baird Northern Wood Frog Rana cantabrigensis Baird 1854a:62 (type locality: Cambridge, Massachusetts, in er- ror; revised to Moose Jaw, Saskatchewan, by Schmidt 1953); Dickerson 1906:212. Rana cantabrigensis cantabrigensis, Howe 1399372. Rana sylvatica cantabrigensis, Schmidt 1938a: 379 (part). Rana temporaria silvatica nec Le Conte, Yar- row 1882a:185 (part). Rana silvatica nec Le Conte, H. Garman 1892: 330. Rana sylvatica sylvatica nec Le Conte, Cagle 1941:9 (part). Diagnosis.—A subspecies of Rana sylvat- ica (largest Illinois specimen 48.8 mm. from snout to vent), smaller than R. s. sylvatica -and differing from it in having shorter legs (tibia less than 55 per cent of body length) ; proportionately shorter head (usually less than 33 per cent of the snout-vent length) ; usually spotted breast; frequently a dorsal pattern of dark, light, or both dark and light | longitudinal stripes between the dorsolat- eral folds; and often raised ridges between the dorsolateral folds. Variation.—Sexual dimorphism exhibited by R. s. cantabrigensis is the same as in R. s. | sylvatica. ' Suzuki (1951) mentions that the tibiae of |immature Wisconsin wood frogs are propor- tionately shorter than those of adults. Juve- jniles are larger headed and less richly colored. | Five specimens from extreme northwest- ern Illinois vary as follows: snout-vent length 38.8 to 48.8 mm.; head length 30.5 to 35.6 (average 32.1) per cent of body length; tibia 52.4 to 55.8 (average 53.6) per cent of body length; femur 48.7 to 53.1 (average 50.2) per cent of body length; 80 per cent jwith spotted breasts; and 80 per cent with dark interorbital markings. Habits.—The northern wood frog is sim- ilar to the eastern subspecies in habits, al- though it shows somewhat greater ecologi- cal tolerance, inasmuch as it is sometimes found in open areas and along grassy stream borders (Pope 19444). Its breeding season is somewhat later because of its more north- ern distribution. Illinois Distribution.—R. s. cantabrigen- sis is known in Illinois by only five speci- mens, fig. 93. Very little field work has been done in northwestern Illinois early enough in the spring to encounter breeding wood frogs, but habitats that appear to be suitable for the species are fairly extensive. When more early spring collecting is done, this race may prove to be more general in occurrence. The specimens from Jo Daviess County deserve special comment. The col- lector reported that they were taken in a woodland pond near Galena, Illinois, but their general appearance strongly suggests a more northern provenance. Although undocumented by _ specimens, a published record for the following local- ity is believed valid and is indicated on the distribution map by a hollow symbol: PEorta County: Peoria (H. Garman 1892). MICROHYLIDAE This large family contains two genera in the United States and numerous genera in the New World and Old World tropics. Gastrophryne Fitzinger Some authors believe that in the United States this genus contains a single polytypic species; others regard it as comprising two species, one consisting of several subspecies. One form enters southwestern Illinois. Gastrophryne carolinensis carolinensis (Holbrook) Eastern Narrow-Mouthed Toad Engystoma carolinense WHolbrook 1836:83, pl. 11 (type locality: Charleston, South Carolina) ; Davis & Rice 18834:27. Gastrophryne carolinensis, Jordan 1929:226. Microhyla carolinensis carolinensis, Hecht & Matalas 1946:5. Microhyla carolinensis, P. W. Smith 1948:2. Diagnosis.—A small, squat-bodied frog (largest Illinois specimen 33 mm. from snout to vent), fig. 94, without webbing be- tween the toes and without a visible tym- Fig.94.—An adult Gastrophryne carolinensis carolinensis from Randolph County, Illinois. — The groundcolor is olive, dark gray, rusty red-brown, or almost black. o panum; with a transverse fold of skin or a groove behind the head; head pointed, its width half or less than half the greatest body width, its length less than one-fourth the body length; dorsum red-brown, gray, or almost black, plain or irregularly blotched, with a tendency toward a median dark band that gradually widens posteriorly. Variation.—During the breeding season of this toad the male differs from the fe- male in having loose, discolored skin on the throat, but at other times specimens are ex- tremely difficult to sex by external charac- ters. The chin spinules noted on the male by Mittleman (1950) are not present on any of the Illinois frogs, although they are evi- dent on a series of males from the Gulf Coast. The immature frog differs from the adult in its proportionately wider head. The sides of the body in the juvenile are nearly par- allel, whereas in the adult they diverge rap- idly. Two specimens from adjacent Missouri (Wayne County) are 37.2 and 37.6 mm. in Ittinois Narurat History SurvEY BULLETIN Vol. 28, Art. 1 snout-vent length, thus exceeding the previ- — ously known maximum size (36.0 mm.) for — this species. Fifteen Illinois specimens from — Monroe and Randolph counties vary as fol- :: lows: head width 25.6 to 32.8 (average ” 29.2) per cent of the snout-vent length; ~ tibia 36.4 to 42.9 (average 39.0) per cent of © snout-vent length; all are mottled ventrally, and almost half of them have lateroventral light markings between the front and hind — legs. The dorsal pattern is variable, but all Illinois individuals have vague dorsolat-- eral light bands. Habits.—The eastern narrow-mouthed toad is a small frog, usually found in rotten stumps, or under flat rocks, bark, or other objects on the ground. Upon being uncoy- ered, this frog appears dazed by light, but after an instant it darts away in a series of short, rapid hops. Occasionally two or three individuals may be found under one rock. In the South the narrow-mouthed toad breeds throughout the summer. I have not found eggs or larvae of this toad in Illinois, but I have heard the low, nasal buzz of the November, 1961 male near Valmeyer on two occasions, both in June. According to Wright & Wright (1949), each female produces approximately 850 eggs as small surface films, one layer deep, each layer composed of 10 to 90 eggs. The egg of this species is unique among IIli- nois amphibians in that it has a flat surface rather than being perfectly spherical. Hatch- ing occurs in a few days, and transformation is said to occur in 20 to 70 days. The tad- pole is unique inasmuch as it has a sucking disc rather than labial teeth, mandibles, and oral papillae. Illinois Distribution—The eastern nar- row-mouthed toad has been assumed to oc- cur in Illinois since Davis & Rice (1883a) published the first check list of Illinois am- phibians and reptiles, but no specimens were secured until 1948. Since a number of col- lectors had attempted unsuccessfully to find the species in the southern tip of the state, Fig. 95.—Distribution of Gastrophryne caro- linensis. Hatching indicates the presumed range of the subspecies carolinensis in Illinois; solid circles indicate localities represented by | specimens examined during this study. ‘The | lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 113 it was with some surprise that I discovered a colony of narrow-mouthed toads within 35 miles of St. Louis, fig. 95. Systematic collecting, aimed at extending the known range of the species, has shown it to be com- mon along the Mississippi River bluffs of Monroe and Randolph counties but has re- vealed no greater range than this. Its range in adjacent Missouri is poorly known. Shortly after the discovery of Gastro- phryne in Illinois, a specimen was recorded from southeastern Iowa (Klimstra 1950). The apparently disjunct range of the spe- cies suggests that this frog was formerly widespread in occurrence and that some ad- verse environmental conditions, presumably lower temperatures, have reduced the range to relict colonies in the Mississippi River val- ley. It appears unlikely that the species has simply been overlooked in the intervening areas, since it is ordinarily easily collected and could scarcely have been missed in such well-known areas as Reelfoot Lake, Ten- nessee, and extreme southern Illinois. Class REPTILIA Turtles, Lizards, and Snakes It is believed that reptiles were derived from Labyrinthodontia amphibians in the Pennsylvanian age. Although the primitive reptiles shared many similarities with cer- tain extinct amphibian groups, reptiles as a class apparently appeared in an explosive evolutionary burst, flourished in great vari- ety throughout the Mesozoic Age, and di- minished with the appearance in the Ceno- zoic Age of the birds and the mammals, both of which were better adapted for a way of life on land. There are relatively few pres- ent-day reptiles. The fossil record reveals three extinct subclasses and 1! extinct orders in addition to the three subclasses and four orders represented by surviving forms. The relationship of the subclasses, orders, suborders, and families represented in IIli- nois may be summarized in the following synopsis. Subclass Anapsida.—Temporal region of skull encased in bone, fossae lacking. Order Testudines——Body enclosed in a shell, consisting of an upper cara- pace and a lower plastron; jaws toothless. Suborder Cryptodira—Toes present; 114 4 or 5 claws on each front foot; shell with horny plates. Family Chelydridae—Bridge nar- row; plastron cruciform, consist- ing of 9 or 10 plates. Family Kinosternidae.—Bridge broad; plastron consisting of 11 plates. Family Testudinidae——Plastron large, consisting of 12 plates. Suborder Trionychoidea—Three claws on each foot. Family ‘Trionychidae.—Shell de- pressed, leathery; snout probos- cis-like. Subclass Lepidosauria.—Skull a modified diapsid type. Order Squamata.—Body completely scaled. Suborder Sauria.—External ears us- ually present; movable eyelids us- ually present; limbs usually pres- ent. Family Iguanidae.—Pineal eye present; subdigital carinae pres- ent; venter scaled; femoral pores present. Family Scincidae.—Pineal eye ab- sent; usually smooth, overlap- ping scales on dorsum and ven- ter; femoral pores absent. Family Anguidae—Longitudinal groove along each side of body (in North American species) ; femoral pores absent; the only representative in Illinois limb- less. Family ‘Teiidae—Granular dor- sal scales; venter with transverse plates; femoral pores present. Suborder Serpentes.—External ears absent; movable eyelids absent; limbs always absent. Family Colubridae——Hollow, mov- able fangs and venom glands ab- sent, no loreal pit between eye and nostril on side of head. Family Crotalidae—Hollow, mov- able fangs and venom glands present, loreal pit between eye and nostril. For ease in identification, the Illinois spe- cies of Reptilia are diagnosed in three large keys, the turtles (order Testudines) in one, the lizards (suborder Sauria) in the second, I_ttinois NArurAL History SurvEY BULLETIN Vol. 28, Art. 1 and the snakes (suborder Serpentes) in the third. Illinois representatives of these three groups may be identified with the aid of the following key. 1. Body enclosed in a shell; jaws without teeta ios Order Testudines, p. 114 Body not enclosed in a shell; jaws with teeth .... {5.0.50 Se eee 2. Body having four legs). eee oe PK hsp. Suborder Sauria, p. 159 Body having no legs 3 3. External ear openings present; movable eyelids present; venter scaled or plated, without transverse scutes; mandibles of lower jaw fused anteriorly... ; parties Rls. Hee The anguid genus Ophi- saurus in the suborder Sauria, p. 163 External ear openings absent; movable eyelids absent; venter with transverse scutes; mandibles of lower jaw sepa- rate and free anteriorly .... Suborder Serpentes, p. 172 Order TESTUDINES Turtles Seventeen species and subspecies of tur- tles occur in J]linois. Four species have IIli- nois populations of one subspecies each and an adjacent intergrade population or an IIli- nois population that is entirely intergrade between two subspecies. The intergrade populations, although included in the key for identification, have not been regarded as en- tities. Most of our turtles are aquatic, although a few species are terrestrial in habit. Some aquatic species are predominantly stream animals; some are pond or lake animals; others occupy either still or running water. One terrestrial species inhabits forest; the other, prairie. They range in size from the — 4-inch musk turtle to the 24-inch alligator snapper. Some species are carnivorous, some omnivorous, and some do a certain amount of scavenging. Turtles are of economic im- portance because several kinds are prized as food for man, the principal food species being the snapping turtle and two species of soft-shelled turtles. Along the major rivers of Illinois, several of the large aquatic tes- tudinids also are utilized for food. Some tur- tles, particularly the snappers and soft-shells, are accused of being important predators of fish, but the current opinion of fishery biol- ogists is that turtle predation is insignifi- cant insofar as fish populations are con- cerned. November, 1961 Most turtles have a courtship preceding mating, and in some species this is an elab- orate performance. Turtle eggs are round or elongate, hard-shelled or membranous- shelled, the shape and type of shell depend- ing on the species. Typically, eggs are de- posited in early summer in loamy soil several yards from water. The nest excavation and concealing activities are often complicated processes, including the discharging of cloa- cal water to moisten the nest site. The hatchling turtles emerge from the ground in early fall or, in some instances, the follow- ing spring. The hatchling turtle is recognizable by its small, usually rounded shell, prominent um- bilical scar, and sometimes by the retention of the “egg tooth.” Growth is relatively slow; the length of time necessary for sex- ual maturity varies widely with the different species. The longevity of some turtles is ap- parently similar to that of man. Some spe- cies shed their shell laminae at intervals; others do not. In the latter group concentric growth rings are present which may provide an indication of the age of the turtle. Turtles, particularly young specimens, are popular pets. Because many of them escape or are deliberately released outside their natural range, distributional records must be evaluated with caution. The 17 species and subspecies of Illinois turtles are divisible into five groups. One group includes six species that are either poorly known (Kinosternon subrubrum and Graptemys pseudogeographica) or have ranges in which II]linois is approximately cen- tered (Chelydra serpentina, Sternothaerus odoratus, Graptemys geographica, and Tri- onyx muticus). Another group (including Macroclemys temmincki, Pseudemys scripta elegans, and the Pseudemys concinna X flor- idana hybrid population) is essentially south- ern in distribution, with northward exten- sions into Illinois in the Mississippi River valley. A group of four species (Clemmys guttata, Terrapene carolina carolina, Chrys- emys picta marginata, and Trionyx spini- er spinifer) is predominantly eastern, and Illinois lies at the western edge of the range of each. The fourth group includes hree Great Plains species (Kinosternon avescens, Chrysemys picta belli, and Terra- ene ornata), which reach Illinois from the est. One species (Emydoidea blandingi) SmitH: AMPHIBIANS AND ReptTILes oF ILLINOIS 115 is northern, extending southward into IIli- nois for approximately half the length of the state. Key to the Order Testudines (Turtles) 1. Carapace leathery and covered with skin, without plates; front foot with 3 claws (Trionychidae) Carapace plated with horny shields, fig. 96; front foot with 4 or more claws...4 NUGHAL MARGINALS COSTALS CENTRALE GULAR HUME RAL AXILLARY PECTORAL ABDOMINAL INGUINAL FEMORAL MARGINAL ANAL Figs. 96-97.—Dorsal and ventral views of the shell of a turtle, Graptemys pseudogeo- graphica. 2. Anterior edge of carapace with spiny pro- tuberances; incomplete nasal septa pres- ent; 2 lateral head stripes per side... .3 Anterior edge of carapace smooth; nasal septa absent; 1 light head stripe on each side ..... Trionyx muticus muticus 3. Black ocelli on carapace sharply decreas- ing in size peripherally. Pee ee Dacre teeta Trionyx spinifer sptnifer Central and peripheral ocelli subequal... . _.Trionyx spinifer spinifer X hartwegi 4. Plastron with 12 plates, fig. 97 (Tes- tudinidae) Plastron with 11 or fewer plates, fig. elets ka i a Ya tats oh ariel Myon hte else) Wiel vive, O@lis ere) mie re 116 Intrnoris NaturAL History SurveEY BULLETIN Vol. 28, Art. 17 100 105 Figs. 98—106.—Characteristics of turtles: 98, plastron of Kinosternon flavescens; 99 plastron of Chelydra serpentina; 100, shell of Terrapene ornata; 101, shell of Pseudemys scripta; 102, head of Chrysemys picta, face view; 103, head of Graptemys pseudogeographica face view; 104, jaws of Graptemys pseudogeographica; 105, jaws of Pseudemys scripta; 106, jaws of Pseudemys concinna hieroglyphica X floridana hoyi; a, alveola; h, hinge. November, 1961 10. 1 12. 13. —— 14. Plastron with 11 plates; posterior margin of carapace not serrate, fig. 98 (Kinos- ternidae) .. Plastron with fewer than 11 plates, fig. 99; posterior margin of carapace serrate (Chelydridae) Piastron incompletely cornified; head usu- ally with yellow stripes along sides; carapace arched Sternothaerus odoratus Plastron completely cornified; head with- out yellow stripes; carapace depressed .7 Ninth marginal plate triangular and much higher than eighth; head slate color, without spots .... ._Kinosternon “flavescens Spooner Ninth marginal plate no higher than eighth; top of head with light and dark SPOUSE eect ee) spare sets Kinosternon subrubrum subrubrum X hippocrepis Top of head with enlarged plates; cara- pace with some marginals separated from costals by 3 to 5 supramarginals Macroclemys temmincki Top of head ‘without enlarged plates; carapace with supramarginals absent Re ieetle ., Chelydra serpentina serpentina Carapace highly domed, the height more than 44 per cent of length, fig. 100; plastron with well-developed hinge, per- mitting shell to be tightly closed; toes with vestiges of webs only; jaws beaked Carapace not “highly domed, greatest height less than 43 per cent of length, fig. 101; plastron with bridge or with limited movement that does not permit shell to be entirely closed; toes webbed ; jaws not beaked Carapace with middorsal keel; apex of upper jaw without notch; axillary ele- MeNteeaOSENtime rt) once ee Pet Carapace without trace of median keel; apex of upper jaw notched; axillary element present + CREO Ceca ORT ACER Terrapene ornata ornata Hind foot with 3 claws; carapace pattern dimipor absent) <.caclscesen aw aden a5 Terrapene carolina triunguis X carolina Hind foot with 4 claws; carapace boldly marked with yellow or orange .... Terrapene carolina carolina Carapace globular; black, with scattered yellow spots Carapace depressed or angular in cross section; shell not black with scattered Fie llowASPOtSIae Peer alae: Ales nee ne 14 Underside of chin and neck immaculate yellow; many yellow flecks in each cara- pace shield, each smaller than orbit... aid Emydoidea blandingi Underside of chin and neck predominantly dark; a few yellow spots in each cara- pace shield, some as large as orbit..... Clemmys guttata Marginals marked with red; apical notch in upper jaw flanked by toothlike pro- jections, fig. 102 .. ste) Marginals marked with yellow or with SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 15. 16. 17. 18. 19. 20. iy) greenish white; apical notch in upper jaw, if present, without adjacent “teeth,” Neel O SES. as Ren, Bs ene Se 17 Plastron immaculate yellow or red; mid- dorsal red stripe half the width of orbit Chrysemys picta dorsalis X marginata Plastron with a dark figure; middorsal red stripe appearing as a thin line, if wasiblettat Talli. ee: Ae ee 16 Dark plastral figure occupying 60 per cent or more of plastron, containing light vermiform markings and sending pro- cesses peripherally along the seams; carapace with irregular yellow lines at least on costals.. Chrysemys picta belli Dark plastral figure an elongate central blotch occupying less than 60 per cent of plastron; figure dark, without pro- cesses extending along seams; carapace Without yellow, limestees eee eee Sadi ts Sores Chrysemys picta marginata Alveolar surfaces of upper jaw smooth; apex of lower jaw rounded, fig. 104. .18 Alveolar surfaces of upper jaw with median ridge or toothlike projections; apex of lower jaw pointed, fig. 105. 19 A pair of small, isolated yellow spots on occiput, each separated from eye by 2 or more thin, diagonal yellow lines Graptemys geographica A pair of boomerang-shaped yellow mark- ings on occiput, each separated from eye by no more than 1 diagonal line Graptemys pseudogeographica Alveolar surfaces of upper jaw with un- equal, toothlike projections, fig. 106; most prominent head markings consist- ing of a pair of yellow stripes arising on snout and passing between the eyes onto the neck _ Pseudemys concinna hieroglyphica X floridana hoyi Alveolar surfaces of upper jaw with median, smooth or finely serrate ridges, fig. 105; most prominent head mark- ings consisting of a pair of red or brown postonbital bands se ene perenne 20 Head with pair of conspicuous, red post- orbital stripes; each costal plate with a median, light transverse bar bordered by parallel, thinner dark and light lines Pseudemys scrifta elegans Head uniformly dark or mottled; post- orbital bands, if present, not red: each costal plate olive or brown, without definite pattern except for dusky mar- gins of carapace seams _melanistic Pseudemys scripta elegans CHELYDRIDAE Two New World genera are placed in the family Chelydridae. A third genus, re- ported to be restricted to New Guinea, has been shown recently an erroneously to have been based on labeled and misidentified specimen of the common snapping turtle, 118 Chelydra serpentina. Some authors prefer to include the family Kinosternidae in the Chelydridae. Chelydra Schweigger The genus contains only two species, one restricted to Central America and one oc- curring from southern Canada to Ecuador. The wide-ranging species contains two sub- species, one of which, the nominate sub- species, occurs throughout Illinois. Chelydra serpentina serpentina (Linnaeus) Common Snapping Turtle Testudo serpentina Linnaeus 1758:199 (type locality: “warmer regions”; revised to vicin- ity of New York City by Schmidt 1953). Chelonura serpentina, Kennicott 1855:591. Chelydra serpentina, Davis & Rice 1883a:32. Chelydra serpentina serpentina, Pope 1939:72- 83. Chelydra sp., Cagle 19444:105. Chelydra, Cagle & Chaney 1950:388. Diagnosis.—A large aquatic turtle (larg- est Illinois specimen approximately 300 mm. from anterior to posterior end of carapace), fig. 107, with an enormous head, thick, pow- erful legs, and a relatively long tail; cara- pace in young with 3 longitudinal keels, in I_tinors NaTuRAL History SurvEY BULLETIN Vol. 28, Art. 1 adults with keels worn off but rough and usually coated with algal growth; posterior edge of carapace serrate; plastron cruci- form and inadequate to conceal legs, neck, and tail; head pointed, covered with tuber- culate skin; jaws strong; small, paired gular barbels; eyes dorsolateral in position; underside of tail plated with large scales; in young, groundcolor black, with some olive or gray mottling and spotting on sides of head, plastron, and underside of soft parts; subadults and adults dirty olive, gray, or brownish black above, with some evidence of radiating rows of dark flecks on each cara- pace plate, or carapace almost patternless; soft parts gray or light olive; beak with nu- merous dark dashes. Variation.—The basal portion of the tail is on the average longer in the male than in the female of the snapping turtle, and the vent is posterior to the rear edge of the carapace. In the female the anus is usually about even with the posterior edge of the carapace. Although ratios have been tested in an attempt to find a method for sexing this turtle by external characters, none has proved reliable. Part of the difficulty in sexing these turtles is due to a remarkable change in proportionate tail length as the turtle becomes larger. Fig. 107—An adult Chelydra serpentina serpentina from Vermilion County, Illinois. Young specimens are predominantly black; older individuals are dirty olive or brownish black. Most large specimens have growths of algae on the carapace. several proportional — my wore wn A pe Tine ne Or a oth A ae i de ht ole SG A oe aes ( Alexander. . H. Garman 1892.... | Z Calhoun. Parmalee 1954...... | 108 Jackson. - Cahn 1937-5 96 Jackson..... UIMNH 24962...... 17 Jackson.... Jess Grammer..... 160+ Jersey John F. Wanamaker | ? Mason..... Lewistown Commun- ity High School bi- ology department. 404 Massae!. ». | Cahn 1937.02. --- 103 Rock Island Schroder 1957.....:- | 54 Randolph... | Cahn 1937.......... 33 Union... .- H. Garman 1892.... ? Union..... E. C. Galbreath. . ? Wabash. Hay: 188iacs So. ? White. . | H. Garman 1892 ? 122 Cahn (1937) reported that the food of the alligator snapper consists primarily of fish, and he presumed that almost any small animal coming within striking distance of the jaws might be eaten. Almost nothing is known of the life his- tory of this rare turtle within Illinois. The eggs are spherical and presumably much larger than those of any other Illinois spe- cies. In the South the number of eggs va- ries from 15 to 50, presumably the size of the female governing the number deposited. Illinois Distribution.— The alligator snapper occurs in the Mississippi, lower IIli- nois, Ohio, and Wabash rivers and their as- sociated tributaries and may occur in swamps and streams throughout the south- ern fifth of the state. It is extremely rare. In 15 years of collecting and of visiting com- mercial fishermen, I have never encountered Fig. 110.—Distribution of Macroclemys tem- mincki. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Intinors NATURAL History Survey BULLETIN Vol. 28, Art. a specimen in the state, except for a 90- pound individual found dead near Carlyle; subsequently I learned that it had been brought from Tennessee to the local Sta Fish Hatchery and then discarded. Never theless, occasional specimens are taken by Illinois commercial fishermen, and, if the come to the attention of biologists, are re- ported in the literature, table 31 and fig. 110. KINOSTERNIDAE Two genera of this family occur in the United States and Canada. Both are in Illi- nois. Some authors regard the Kinosternidae as a subfamily of Chelydridae. Sternothaerus Gray Four species of Sternothaerus, one of which consists of several subspecies, occur ir the United States and Canada. The range of one monotypic species covers all Illinois. Sternothaerus odoratus (Latreille) Stinkpot Musk Turtle Testudo odorata Latreille 1801:122 (type local- ity: Carolina; revised to vicinity of Charles ton, South Carolina, by Schmidt 1953). Aromochelys odorata, Hay 1887a:16. Aromochelys odoratus, Davis & Rice 1883a:32. Sternotherus odoratus, Blanchard 19245:540. Kinosternon odoratum, Evermann & Clark 1916:479. Aromochelys carinatus nec Gray, Davis & Rice 1883a:32. Aromochelys carinata nec Gray, Hay 1892:593 Sternotherus sp., Cagle 1944a:105. 3 Sternotherus, Cagle & Chaney 1950:388. Diagnosis.—A rather small aquatic tur- tle (largest Illinois specimen having a caré pace length of 128 mm.), fig. 111, with an oval-shaped, usually high-domed shell; 1 poorly ossified plates; pectoral scutes broad ly in contact, the suture between at least equal to the interhumeral suture; pectora scutes never triangular in shape; anterio portion of the plastron much shorter thar posterior part; tenth and eleventh marginal plates much higher than anterior marginals; plastron usually with a considerable amou of cartilaginous material bordering the su tures; head large; nose projecting well be yond mouth; a pair of barbels on chin; us ally a pair of yellow stripes on each side 0 head; carapace black, olive, or mottlet November, 1961 SmitH: AMPHIBIANS AND ReEpTILES OF ILLINOIS Fig. 111.—An adult Sternothaerus odoratus from Tazewell County, Illinois. and soft parts are olive, brownish, or black. On most specimens a pair of yellow stripes extends along each side of the head. brownish black and olive, occasionally with radiating dark lines or series of dashes. Variation—The stinkpot male differs from the female in its much larger tail, the prominent claw on the tip of the tail, and the presence of two small horny patches on the inner side of each hind leg. The male tends to have a less ossified and proportion- ately shorter plastron. In 16 males the plastron length ranges from 67.0 to 78.7 (average 73.3) per cent of the carapace length ; in 21 females the range is from 75.0 to 90.3 (average 79.7) per cent. The hatchlings, which range from 21.5 to 27.2 mm. in carapace length, have black car- apaces and soft parts; usually some light marks are present on most of the marginal The shell scutes. The plastron is marbled with black and yellowish white or gray. The carapace has a prominent middorsal keel and a sec- ondary lateral keel on either side of the mid- dorsal. Subadults are dark olive or brown and have radiating dark lines or a series of spots on each carapace shield. The venter is pre- dominantly light; the head pattern is similar to that of hatchlings. The middorsal keel is less prominent than in young, and in most individuals the lateral keels have been lost. In adults the carapace is usually dark above, with some mottling, although it is sometimes almost a uniform olive. It is smooth and exhibits a tendency to become somewhat flattened on top. The head stripes Table 32.—Ontogenetic variation in carapace proportions of Illinois Sternothaerus odoratus. Figures in parentheses are numbers of specimens. CARAPACE LENGTH (MM.) CHARACTERISTIC Under 30(20) 30-70(2) 70-100(21) Over 100(15) |- 7 eee Range Mean Range Mean | Range | Mean Range Mean |Width as percentage | | | | Mmpotlength......... IS D5 8) BOAO WIT Wek Oe asyil 5—82.0] TOES) (64.5—-74.3 68.8 Height as percentage | | oflength......... 52.7-75.5| 57.3 |46.3-48.6| 47.4 |37.2-53 2| 43.2 |37-2-46.2| 41.6 124 may be lost on some very old individuals. The head and neck often have a dimly mot- tled pattern. As a stinkpot grows, it becomes progres- sively more elongate, and the shell becomes somewhat depressed. These ontogenetic changes are summarized in table 32. No definite geographic variation in this species within Illinois has been noted, al- though a small series from extreme northern Illinois suggests that the head stripes may be narrower and may be lost at a smaller size in the northern turtles than in turtles from farther south. Habits.—The stinkpot is aquatic and is not often seen away from water. It is a good swimmer, but its normal behavior con- sists of crawling over the mud bottom of ponds, searching aquatic vegetation for food. This elongate turtle is notoriously ill-tem- pered; even a baby turtle not yet free of the egg will snap at objects that annoy it. In addition to its powerful jaws, the stinkpot possesses four scent glands situated on the sides of the body. The musk is extremely unpleasant; many individuals are apparently reluctant to emit the scent. Sternothaerus odoratus is carnivorous, feeding on aquatic arthropods, fish, anne- lids, and mollusks. Captives take almost any kind of meat offered. Egg laying occurs in the late afternoons in June. The nest site is several yards from a pond. Cahn (1937) records the clutch size as 3 to 5. The elliptical, hard-shelled eggs, which average about 27.5 X 15 mm., hatch in early fall. Illinois Distribution—The stinkpot un- doubtedly occurs in every Illinois county, fig. 112. Although this species is found in rivers and even small streams, it is probably most abundant in permanent ponds and relatively shallow lakes. Usually special efforts must be made to find this turtle in the mud of bodies of water, and for this reason the ac- companying map does not reflect the actual abundance of Sternothaerus in Illinois. Although undocumented by specimens, published records for the following locali- ties are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Homewood, Wolf Lake (Schmidt & Necker 1935); Du Pace County: Hinsdale (Necker 1939c); Fay- ETTE County: Vandalia (Cahn 1937); ILttinoris NATURAL History SurRVEY BULLETIN Vol. 28, Art. 1 ee ee ee. en ee ee ee a | Fig. 112.—Distribution of Sternothaerus odoratus. The species occurs throughout Illinois. Solid circles indicate localities repre- sented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. JAcKson County: Elkville, Grimsby (Ca gle 19424) ; KANE County: Aurora (Cahn 1937); KANKAKEE County: Momence (Cahn 1937); Knox County: 214 mi. E Galesburg (Adcock 1922); Lake County: Deep Lake (H. Garman 1892); Fox Lake, Nippersink Lake, Round Lake (Schmidt & Necker 1935); Lawrence County: Law- renceville (Cahn 1937) ; Livincston Coun- TY: Pontiac (Cahn 1937); McHenry County: McHenry (Necker 1939c) ; MAp- Ison County: (Hurter 1911); Massac County: Metropolis (Cahn 1937); Me- NARD County: Petersburg (Cahn 1937); RANDOLPH County: Chester (Cahn 1937) ; Rock Istanp County: Rock Island (Cahn 1937) ; St. Ctarr County: (Hurter 1911); SALINE County: 3 mi. W Carriers Mills (Blanchard 19246); TazeweLtt County: Pekin (H. Garman 1892) ; WasasH CouN- November, 1961 ry: Mount Carmel (Hay 1887a); WHITE County: Phillipstown (H. Garman 1892) ; WHITESIDE County: Prophetstown (H. Garman 1892); WuLLIAMSON CouUNTY: Marion (Cagle 19425). Kinosternon Spix Five species of this New World genus, most of them polytypic, occur in the United States and Canada, two in Illinois. Kinosternon flavescens spooneri Smith Illinois Mud Turtle Kinosternon flavescens spooneri P. W. Smith 1951:195 (type locality: Henderson County State Forest, 7 mi. N Oquawka, Illinois). Kinosternon flavescens, Cahn 1931:120-3. Kinosternon flavescens flavescens nec Agassiz, Pope 1939:52-5. Diagnosis.—A medium-sized aquatic tur- tle (largest Illinois specimen with a cara- ie SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 125 pace length of 145.5 mm.), fig. 113, with an obtusely oval, much-depressed shell; plas- tron large and consisting of 11 plates; pec- toral scutes triangular in shape and nar- rowly in contact; length of interpectoral suture less than one-fourth length of inter- humeral suture; ninth marginal more than twice height of eighth marginal; anterior and posterior parts otf plastron approxi- mately equal in length; head of medium size; nose not noticeably projecting beyond mouth; paired barbels on chin and neck conspicu- ous; head a uniform dark above, lighter be- neath, with some yellow in patches; cara- pace black, brownish black, or dark olive, patternless or with black margins along the sutures. Variation.—Sexual variation in the I[lli- nois mud turtle is similar to that found in the musk turtle. Males possess larger tails, more prominent horny tips on the tail, and two patches of horny skin on the inside of Fig. 113.—Adult Kinosternon flavescens spooneri from Mason County, Illinois. Young specimens are nearly black; older individuals, dark olive or brownish black. 126 each hind leg. Cahn (1937) noted that males tended to be larger and to have heav- ier upper beaks. The sexual dimorphism in proportionate plastron length is more pro- nounced in this turtle than in Sternothaerus odoratus. In nine adult males at hand the plastron length ranges from 84.5 to 87.5 Table 33.—Ontogenetic variation in carapace proportions of Illinois Kinosternon flavesce spooneri. Figures in parentheses are numbers of specimens. IntrNors Natura History Survey BULLETIN Vol. 28, Art. trace of pattern. The beak on old individ-— uals is often flecked with numerous dark dashes. a The carapace of the mud turtle becomes” more elongate as this turtle attains adult- hood; in old specimens it is even flatter than — in juveniles, although the proportionate shell — CARAPACE LENGTH (MM.) CHARACTERISTIC Under 100(4) 100-130(7) | Over 130(7) | Range Width as percentage of length.......... Height as percentage of length......... (average 85.4) per cent of the carapace length; in six adult females at hand the range is from 95.0 to 98.5 (average 96.9) per cent. Data on ontogenetic changes in this spe- cies are fragmentary and are at variance with published information. Cahn (1937) described the young as being similar to the adults except that hatchlings are more cir- cular in form and lack the elevated ninth and tenth marginals. Cahn’s remarks were based on an examination of Oklahoma juve- nile Kinosternon flavescens flavescens, how- ever, and it is almost certain that these char- acters do not apply for spooneri, which has a distinctively patterned subadult. No hatchlings of this species are available from Illinois, but the variation in the adults and subadults extant suggests an ontogenetic change in color and pattern. This change provides an additional character for sep- arating spooneri from the subspecies flaves- cens. The smallest specimens at hand are 61 and 70 mm. in carapace length. These subadults are distinctly different from any K. f. flavescens and from the largest speci- mens of spooneri in the very dark color of the shell and soft parts and in the irregular but discrete small light markings on the chin. Specimens up to 100 mm. in carapace length retain some trace of the head pattern and in each the underside of the head and neck is dark gray, with yellow restricted to the lower mandible and barbels. Adult speci- mens are lighter in shell color, and the chin and neck are dark yellow-gray, without a Mean | 78.5-87.0) 83.4 35.3-43.0|} 39.6 Mean Range | Mean 72.3-82.0| 76.9 |58.0-71.5| 68.9 & 34.0-43.5| 39.4 |32.1-36.2| 33.9 height does not decrease as regularly as in the musk turtle. The ontogenetic changes” in shell proportions are summarized in table 33. Illinois mud turtles occur in three ap- parently isolated populations in this state but the samples available are rather homoge- neous. Since the original description was published, a few additional specimens have become available to supplement those from which the ratios of plastral elements to each other were derived; the additional data de not appreciably alter the means given in th original description. The gular length ranges from 80 to 140 (average 108) pe: cent of the interhumeral suture length and from 44.7 to 55.5 (average 50.2) per ce of the length of the anterior lobe of tht plastron. Habits.—The mud turtle is rather slow and awkward on land. In captivity it adept at digging, even in dry soil. It is | strong swimmer; when undisturbed, it fo ages in the silty bottoms of ponds a sloughs, plowing a furrow similar to tha’ made by a large mussel. It is timid, prefer ring to withdraw into its shell rather thar try to bite. Newly captured mud turtles emi an extremely nauseating musk; the disagree able odor of this secretion persists for hour The Illinois mud turtle is a scavenger 4 well as a carnivore. Captives take mam kinds of food. Of two captive females, one laid thre eggs and the other four eggs in the latte ferred habitats sloughs of the major rivers and ponds in — —————————————————————————————————ooooeEeEeEeEeEeeEeEeEeEeEeEEee=—eEEaaEaeeeeee November, 1961 half of July. The elliptical, hard-shelled eggs averaged 28.5 X 16.5 mm. No hatch- lings have been collected in Illinois. Illinois Distribution—The Illinois mud turtle is known to occur in the sand area along the Illinois River from Morgan to Peoria counties and in Whiteside and Hen- derson counties, fig. 114. The species may occur also in sand prairie ponds and sloughs of the upper Mississippi River. The pre- are probably backwater the sand prairies. K. f. spooneri is one of the striking exam- ples of a relict xerothermic period animal. The closest relative occupies the Great Plains from eastern Kansas westward. As a result of the climatic changes occurring in the Prairie Peninsula, the race spooneri has Fig. 114.—Distribution of Kinosternon flav- escens. Hatching indicates the presumed range of the subspecies spooneri in Illinois; solid circles indicate localities represented by speci- mens examined during this study; the open circle indicates a locality represented by a published record believed to be valid. The lower map depicts the total range of the species in the United. States. SmITH: AMPHIBIANS AND REPTILES OF ILLINOIS 127 evidently been reduced to a few small rem- nant colonies. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: Prorta County: Peoria (Cahn 1937). Kinosternon subrubrum (Lacépéde) Three subspecies of Kinosternon subru- brum are currently recognized. One is re- stricted to peninsular Florida, one occurs from the Atlantic Ocean to Alabama and Indiana, and one occurs from Missouri and Mississippi westward into Texas and Okla- homa. The few Illinois specimens available are intermediate between the eastern and western subspecies and are provisionally re- ferred to K. s. subrubrum X hippocre pis; the subrubrum influence seems to predominate. Kinosternon subrubrum subrubrum (Lacépéde) x hippocrepis Gray Mud Turtle Testudo subrubra Lacépéde 1788:618, 619 (type locality: Pennsylvania; revised to vicinity of Philadelphia by Schmidt 1953). Kinosternon subrubrum subrubrum, Stejneger & Barbour 1917:112. Kinosternon subrubrum, Pratt 1923:238. Kinosternon subrubrum ssp., Cagle 1946:691. Cinosternum pennsylvanicum, Hay 1887a:16. Kinosternon pennsylvanicum, Hurter 1897:501. Diagnosis.—An intergrade population of rather small aquatic turtles (largest Illinois specimen with a carapace length of 120 mm.), fig. 115, each of which is similar to Kinosternon flavescens but differs as follows: tenth marginal plate distinctly higher than preceding marginals; chin reticulated or mottled; sides of head with discrete light spots; carapace brownish black, olive-brown, or yellow-brown, usually with black mar- gins along the sutures of the carapace. Variation.—Sexual variation in K. sub- rubrum is apparently similar to that found in K. flavescens. The male possesses a larger tail than the female, a more conspicuous nail on the tip of the tail, patches of horny skin on the hind legs, and a_ proportionately shorter plastron. In an adult male at hand, 94 mm. in carapace length, the plastron length is 90.5 per cent of the carapace length; in an adult female, 120 mm. in carapace 128 Ittinois NaruRAL History SURVEY BULLETIN Fig. 115.—An adult Kinosternon subrubrum subrubrum from Sussex County, Delaware. P The shell and soft parts are olive or brownish black. Specimens from Illinois usually have irregular yellow spots on the head. (Photo by Isabelle Hunt Conant.) length, the plastron length is 96.7 per cent of the carapace length. The only Illinois hatchling of this turtle available for study has a carapace 22 mm. long; the width of its carapace is 87.3 per cent of the length (73.5 and 74.5 per cent in two adults), and the height is 49.2 per cent of the length (41.6 and 42.5 per cent in two adults). The carapace of the hatchling, which has a median keel and roughened plates, is thus more rounded and proportion- ately higher than that of adults. The tenth and eleventh marginal plates are no higher than the anterior marginals. The soft parts, including the head, and the carapace are black; small light marks are present on the edges of the marginals. The plastron is black centrally, light (probably orange in life) peripherally. The Illinois specimens examined are in- termediate in head pattern between the pa- rental subspecies. None has head stripes, but adults have a variable number of dis- crete light spots on the sides of the head. The sample is too small to provide sufficient data for a study of individual variation. Habits.—This rare turtle is probably similar in habits to the stinkpot and the IIli- nois mud turtle, although the impression is given by collectors that K. subrubrum is more often found on land than other kino- sternids. Captive specimens are rather shy Vol. 28, Art. 1 and usually are not prone to bite. The musk of this turtle is said to be less disagreeable than that of K. flavescens. Feeding, nesting, — and other habits are probably similar to ~ those of flavescens. No life history informa-_ tion is available for this rare species in Illinois. : Illinois Distribution.—The mud turtle is © inexplicably rare in Illinois, fig. 116. South- ern Illinois habitats that appear to be iden- © tical with southern United States habitats, ~ where the species is common, have been searched with little success. The Illinois range of this turtle is un-— known. The Peoria record of H. Garman (1892) and the Mount Carmel record of Hay (18874) would be dismissed as prob- ably referring to misidentified turtles of re-~ lated species, if it were not that a recently © collected specimen from Calhoun County is available, and a colony of K. subrubrum is well known in northern Indiana. Most of” the recent Illinois records are from the southern tip of the state. ; Although undocumented by specimens, published records for the following addi-— tional localities are believed valid and are also indicated on the distribution map by hol-— low symbols: ALEXANDER County: N Cairo © (Cahn 1937); Jackson County: NE part? of county (Cagle 1942a); PoprE County: ~ Dixon Springs (Cagle 1946). November, 1961 Fig. 116.—Distribution of Kinosternon sub- rubrum. Hatching indicates the presumed range of subrubrum X hippocrepis intergrades in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. TESTUDINIDAE Eight genera in this family are found in the United States and Canada. Six are rep- resented by species occurring in Illinois. Clemmys Ritgen Four species of this nearly cosmopolitan genus occur in the United States and Can- ada. One of these barely enters northeast- ern Illinois. Clemmys guttata (Schneider) Spotted Turtle | Testudo guttata Schneider 1792:264 (type lo- cality: not stated; suggested as vicinity of Philadelphia, Pennsylvania, by Schmidt 1953). SMITH: AMPHIBIANS AND RepTILES OF ILLINOIS 129 Clemmys guttata, Necker 1933:8. Chelopus guttatus, H. Garman 1892:215. Diagnosis.—A small aquatic turtle (larg- est Illinois specimen 118.8 mm. in carapace length), fig. 117, with an oval, smooth, rather depressed carapace; posterior mar- ginals flaring outward; plastron large, im- movable, consisting of 12 plates; carapace black, each shield with 1 to 10 prominent, round, yellow spots, each of which is almost as large as eye; plastron predominantly black in very old individuals, light groundcolor with prominent black blotches on subadults, and black groundcolor with light central portion in most adults; head rather small and dark, with scattered yellow spots above; neck dark above and below, sometimes spot- ted with yellow; limbs usually somewhat bi- colored, dark above and orange-yellow be- neath. Variation—Grant (1935) found that the male spotted turtle differs from the fe- male in having a more posteriorly situated anus, a slightly concave plastron (flat or convex in the female), less prominent post- mandibular stripes, brown eyes (orange eyes in the female), and, on the average, fewer yellow crown spots. Hatchlings, according to Carr (1952), are about 28 mm. in carapace length, almost cir- cular in outline, and have one spot per cara- pace plate. The young are said to have fee- ble keels, proportionately longer tails than adults, and plastrons that are light but with a dark central blotch in each. The three available specimens from IIli- nois are not sufficient to indicate the extent of variation of the species within the state. Cahn (1937) cites two specimens from near Wolf Lake, Cook County, and he gives measurements for both turtles. My meas- urements of one of these specimens (the only one now extant) do not correspond to those given by Cahn for either, and this discrep- ancy precludes use of his data. Two adult females have carapace lengths of 118.8 mm. and 103.6 mm., carapace widths of 81.2 and 75.0 mm., plastron lengths of 109.0 and 96.5 mm., and plastron widths of 61.0 and 59.5 mm. mn 36-44 Scale rows at mid-body...............- 40-48 Femoral pores on both sides....... ...| 24-32 Transverse body bands..............-. 5-9 Range | Mean Range | Mean | Range | Mean Fajen ays ¥ 36-76 |... .. 0+) eee ee Statecnteatens 1743130000 ee Bye 40 36-43 40.5 36-42 39.4 43.3 40-50 44.8 40-49 43.8 28.5 24-30 25.2 25-31 28.4 6.3 5-8 6.9 6-8 6.6 open, dry, wooded areas, such as rocky hill- sides or wood lots. This lizard frequently is found in the vicinity of fallen trees, stumps, and rail fences, and often it is heard Ani ie Pill ia 7 i ti 3 Fig. 148.—Distribution of Sceloporus undu- latus. Hatching indicates the presumed range of the subspecies Ayacinthinus in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. scampering over bark before it is seen. It climbs readily and is usually alert, manag- ing to be on the side of a limb or tree trunk opposite the pursuer. When undisturbed, this lizard may be seen flattened against a limb or rock and basking in the sun. During cold or rainy weather, it seeks shelter under bark, logs, or rocks. While hunting food, the northern fence lizard has a rather jerky locomotion and stops at intervals to do “push-ups” with its front legs. Its food con- sists of insects and other arthropods, ants being especially relished (Cagle 1945). Copulation in the northern fence lizard occurs in late April and early May. Gravid females deposit elongate, soft-shelled eggs within rotten stumps or under the bark of decaying logs. Cagle (1942a) found that 8 eggs laid the first of August by a female in southern Illinois averaged 7.5 X 13.5 mm. Hatchlings are generally abundant by the last of August. Illinois Distribution—Fence lizards oc- cur throughout the southern part of Illinois except for the Wabash Border division, fig. 148. Their occurrence becomes increasingly local toward the northern edge of the range, suggesting that temperature may be one of the important limiting factors. Where they occur, they are abundant; their avoidance of Wabash River counties in Illinois and Indi- ana is not readily explained. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Har- pin County: Cave in Rock (H. Garman 1892) ; Putaski1 County: Villa Ridge (H. Garman 1892); Union County: Cobden (H. Garman 1892). November, 1961 Crotaphytus Holbrook This strictly North American genus con- tains four species, according to some au- thors, five, according to others. Two or three, the number depending on the point of view of the specialist, species occur in the United States, and one of these is known from the Mississippi River bluffs in Mis- souri but is not known in Illinois. Crotaphytus collaris collaris (Say) Eastern Collared Lizard Agama collaris Say 1823:252 (type locality: Verdigris River near its union with the Arkansas River, Oklahoma). Diagnosis.—A large iguanid lizard with a broad head distinctly set off from the body by a narrow neck; tail approximately twice as long as snout-vent length; granular scales above, slightly larger scales below; femoral pores present; a distinct black nuchal collar, which is interrupted medially. Distribution—A colony of eastern col- lared lizards at Pevely, Missouri, which is on the Mississippi River bluffs opposite Val- meyer, Monroe County, Illinois, was known to Hurter (1897). This population still ex- ists. I have thus far been unable to find the species on the Illinois side of the river, but there is a slight possibility that a small colony may occur somewhere in the Monroe County bluffs. ANGUIDAE Opinion is divided among American her- petologists on the number of anguid genera in the United States, some authors recog- SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 163 nizing two and others four. The family is predominantly New World in distribution, but a few genera occur in Eurasia and Africa. Ophisaurus Daudin Three species of Ophisaurus, one with two subspecies, occur in the United States. Other species are found in the Old World. The nominate race of the polytypic species occurs over most of Illinois. One other spe- cies may be found in the state, although it is as yet unrecorded here. Ophisaurus attenuatus attenuatus Cope Western Slender Glass Lizard Joint Snake Opheosaurus ventralis attenuatus Cope 1880: 18 (type locality: Dallas, Texas). Ophisaurus attenuatus attenuatus, 1953:138. Ophiosaurus lineatus, Kennicott 1855:591. Opheosaurus ventralis nec Linnaeus, Yarrow 1882a:46. Ophisaurus ventralis nec Linnaeus, Hay 1887a: 14. Ophisaurus ventralis ventralis nec Linnaeus, Cope 1900:500. Ophiosaurus ventralis nec Linnaeus, 1914:4. Schmidt Gaige Remarks.—Although most authors, since the species’ rediscovery, and a check list (Schmidt 1953) credit the name attenuatus to Baird rather than to Cope, it is clear that Cope validated the name and is actually the author. Dallas, Texas, automatically be- comes the type locality. Diagnosis.—A limbless lizard (largest Illinois specimen 726 mm. in total length), fig. 149, with a distinct, dark middorsal stripe; white markings primarily in the mid- Fig. 149.—An adult Ophisaurus attenuatus attenuatus from Harris County, Texas. The groundcolor is greenish gray, tan, or light brown; the stripes are brown or dark gray. (Photo by Isabelle Hunt Conant). Some adults from Illinois have numerous dark and light flecks on the dorsum and are less distinctly striped than the lizard pictured here. 164 dle of the scales, often forming longitudinal light stripes; 1 or 2 dark stripes or rows of dark spots below the lateral line on each side of body; and length of the unregenerated tail of the adult less than 2.4 times the snout-vent length. Variation—The male of the western slender glass lizard presumably possesses a thicker tail proximally than the female, but external characters are not reliable for distinguishing the sexes. The juvenile ap- parently differs from the adult only in size. No geographic variation has been dis- cerned in the meager sample available. Nine specimens yield the following individual variation: snout-vent length 164 to 304 mm.; body length 30 to 33 per cent of total length; ventral scales 127 to 138 (average 130.7) ; supralabials 9+9 to 11+ 12, usually 10 or 11; infralabials 8 + 8 to 11 + 10, usually 9 + 9. Eighty-eight per cent of the specimens have distinct, dark middorsal stripes; 22 per cent possess weak middorsal bands. The two largest specimens possess prominent light markings on the posterior edges of the dor- solateral scales, as well as confluent light lines through the middle of the scales; the remaining seven specimens exhibit only the light lines. One specimen, from Perry County, lacks the ventral rows of spots, two specimens have a single row on each side, four have a double row, and two have three rows. A specimen from Champaign County has a double tail. Habits.—The snakelike ophisaur is ter- restrial and somewhat fossorial. Little is known of its habits in Illinois, aside from the generally known fragility of its long tail. Captives are nervous; those I have kept refused all food offered. A captive specimen of the related Ophisaurus ventralis ate other lizards, small snakes, and crickets, and it is likely that food habits are similar in the two species. Captured individuals do not usually bite, but they must be held gently or the brittle tail will fragment. No information is available for eggs or hatchlings of this lizard in Illinois. Illinois Distribution—This lizard is in- explicably rare in Illinois, fig. 150. It is interesting to note that Garman (1892) be- lieved the species was rapidly being exter- minated within the state. Today, almost 70 years later, the same observation might be made; nevertheless, specimens are still found in Champaign County, one of the Ittrnors Naturat Hisrory SurvEY BULLETIN Vol. 28, Art. 1 most intensively cultivated regions in Illi- nois. Several specimens have been collected in narrow strips of prairie bordering railroads. Judged from reports, the western slender Fig. 150.—Distribution of Ophisaurus at- tenuatus. The subspecies attenuatus appar- ently occurs throughout the state, although it is rare in all sections. Solid circles indicate localities represented by specimens examined during this study; open circles, localities rep- resented by published records believed to be valid. The lower map depicts the total range of the species in the United States. glass lizard is more common in the dissected hills of Calhoun and Pike counties than elsewhere in the state. In Illinois Ophisaurus does not seem to be more common in the sand prairies than on other soil types, as it is in Indiana. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Cook — County: Evanston, Palos Park (Schmidt & Necker 1935); Grunpy County: Pequot (Stille & Edgren 1948); Jersey CoUNTY: Pere Marquette State Park (Link 1939); November, 1961 Knox County: Abingdon (McLain 1899) ; McLean County: Normal (H. Garman 1892) ; PEorra County: Peoria (H. Gar- man 1892) ; WagasH County: Mount Car- mel (Yarrow 1882c). Ophisaurus ventralis (Linnaeus) Eastern Glass Lizard Anguis ventralis Linnaeus 1766:391 (type lo- cality: Carolina; revised to vicinity of Charleston, South Carolina, by Neill 1949c). Ophisaurus ventralis, McConkey, 1952:2. Diagnosis.—A limbless lizard, differing from Ophisaurus attenuatus in the follow- ing characters: white marking occurring on posterior corner of each scale rather than in middle of scale; no distinct middorsal dark stripe; ventral region without dark stripes or rows of dark spots. Distribution.—O. ventralis is a south- eastern species, said to occur northward to southern Illinois (McConkey 1952). No Illinois specimens are extant, but there is an authentic record for it in adjacent St. Louis County, Missouri. TEMDAE The center of distribution of this family is South America. It is represented in North America by one widely distributed genus. Cnemidophorus Wagler Ten species of Cnemidophorus, several of which consist of two or more subspecies, SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 165 occur in the United States, but only one inhabits Illinois. Cnemidophorus sexlineatus sexlineatus (Linnaeus) Six-Lined Racerunner Whiptail Lizard Lacerta sexlineata Linnaeus 1766:364 (type locality: Carolina; revised to Charleston, South Carolina, by Schmidt 1953). Cnemidophorus sexlineatus, Jordan 1878:171. Cnemidophorus sexlineatus sexlineatus, Burt 1931:76-97. Cnemidophorus sex-lineatus, Hay 1887a:14. Diagnosis.—A medium-sized, slender liz- ard (largest Illinois specimen 240 mm. in total length), fig. 151, having granular scales above and 32 to 36 rows of enlarged rectangular scutes below; 2 gular folds; olive, gray, brown, or gray-green ground- color with 6 longitudinal, narrow light stripes extending onto the base of the tail. Variation.—In this species the male dif- fers from the female in having more con- spicuous femoral pores, a heavier tail proxi- mally, less distinct, lateral light stripes, and the frequent presence of a pale blue wash ventrally. Juveniles are shorter tailed than adults. In five young specimens less than 45 mm. from snout to vent, the snout-vent length comprises 32.1 to 38.5 (average 35.8) per cent of the total length, whereas in eight adult females the range is 30.6 to 35.7 (average 32.4) and in eight adult males 30.3 to 34.2 (average 31.9). Six-lined racerunners appear to attain their maximum size in extreme southeastern Fig. 151.—An adult Cuemidophorus sexlineatus sexlineatus from Tazewell County, Illinois. The groundcolor ranges from olive-gray to brown, often with green on the fore part of the body; the dark stripes are dark gray, brown, or almost black; the light stripes are green, gray, or dirty yellow. 166 Illinois. In a series from Brookport, Massac County, four adults range from 70 to 79 mm. in snout-vent length. Elsewhere in the state the largest specimens seldom exceed 70 mm. in snout-vent length. No other geographic variation trends are evident. Scutellation data for 26 specimens are as follows: femoral pores 14 to 19, usually 17, per side; transverse rows of ventral plates between second gular fold and anal plates 30 to 36, average 33.8; lamellae under fourth toe 21 to 29, average 25.2. Habits.—These strictly terrestrial lizards are sun-loving, and on hot, sunny days they are quite conspicuous. On dull or cool days they seek shelter in holes or beneath objects. Whiptails are alert and fast, and shooting is the most profitable collecting technique. The food consists of arthropods. Fig. 152.—Distribution of Cnemidophorus sexlineatus. Hatching indicates the presumed range of the subspecies sexlineatus in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published rec- ords believed to be valid. The lower map de- picts the total range of the species in the United States. Ittinoris NaturAL History Survey BULLETIN Vol. 28, Art. 1 Eggs of this lizard have been found in late June. The eggs, 3 to 5 to a clutch, were in scooped-out hollows in moist sand beneath railroad ties. Hatchlings are in evidence by late July. Illinois Distribution—The racerunner, or whiptail lizard, occurs on hill prairies, in all the major sand areas, and also in the extreme southeastern part of Illinois, fig. 152. It is possible that it may be found also in some of the minor sand areas and in all the counties bordering the Mississippi River. Along the Mississippi River bluffs this species appears to be restricted to the dry hill prairies and is seldom found at the bases of the bluffs. It is most abundant in sand prairies and it shuns woods, wet soil, and soil rich in humus. Although undocumented by specimens, published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Forest Preserves (Pearsall 1940) ; Harpin County: Cave in Rock (H. Gar- man 1892); La Satt—E County: Ottawa (H. Garman 1892); Mason County: 10 mi. N Havana (Hart & Gleason 1907) ; Topeka (Burt 1931); St. Cratrr County: Bluff Lake (Hurter 1893). SCINCIDAE Three genera of this world-wide family of lizards occur in the United States and Canada. Two are represented in Illinois. Scincella Mittleman One monotypic species occurs in eastern United States. Currently most authors re- gard Scincella as a subgenus of the widely distributed Lygosoma. Scincella laterale (Say) Ground Skink Scincus lateralis Say 1823:324 (type locality: banks of the Mississippi River below Cape Girardeau, Missouri). Oligosoma lateralis, S. Garman 1884:14. Oligosoma laterale, Jordan 1878:171. Lygosoma laterale, Moore 1896:752. Liolopisma laterale, Cope 1900:624. Leiolopisma laterale, Surface 1907:251. Leiolepisma laterale, Schmidt & Necker 1935: 60. Leiolopisma unicolor, Stejneger & Barbour 1939:86. Leiolepisma unicolor, Brimley 1941:14. November, 1961 Diagnosis-—A small, slender, lizard (largest Illinois specimen 131 mm. in total length), fig. 153, with 24 to 30 rows of smooth scales around the middle of the body; 59 to 74 dorsal scales in a line be- tween the parietal and a point above the hind legs; frontal scale V-shaped; a window in the lower eyelid; a dorsal groundcolor of SMITH: AMPHIBIANS AND RepTILeEs OF ILLINOIS 167 tan, light brown, or copper, with distinct, dark chestnut dorsolateral bands; supra- nasals absent. Variation—In the ground skink, the sexes presumably differ in the heavier tail of the male, but external characters are not reliable for sexing specimens. Newly hatched lizards appear propor- Fig. 153.—An adult Scincella laterale from Jefferson County, Missouri. The groundcolor is tan or light brown; the lateral bands and dorsal flecks are dark brown. Some specimens, Particularly subadults, are distinctly copper colored above. 168 Ittinois NaturaAL History Survey BULLETIN tionately shorter tailed and longer legged than adults. In nine juveniles less than 40 mm. from snout to vent, the legs, when adpressed, overlap or are separated by as much as 8 scale lengths (average 3.1). In nine adults, the toes of the adpressed limbs are separated by 13 to 24 scale lengths (average 15.5). However, the proportion- ately shorter tail of the young is not evident in subadults, inasmuch as the tail comprises approximately 60 per cent of the total length of all the available specimens 25 mm. or more in snout-vent length. No geographic variation in this species has been discerned within the state. Twenty specimens at hand vary as follows: snout- vent length 24 to 49 mm.; total length 61 to 131 mm.; scale rows at mid-body 24 to 29 (average 26.3); dorsal scales between pa- rietal and point above the hind legs 59 to 74 (average 67); supralabials 5+6 to 7+7 (7+7 in 90 per cent of specimens) ; infralabials 6+ 6 to 7+ 7 (6+ 6 in 60 per cent of specimens); lamellae under fourth toe 14 to 17 (average 15.3). Thirty-seven per cent of the specimens are plain brown above, 47 per cent have a tendency toward having 2 longitudinal rows of dark spots, and 16 per cent are variously flecked with dark markings. H. Smith (1956) gives the range of dor- sal scales as 77 to 80. The source of his counts is presumed to be Kansas specimens. Habits.—This small, terrestrial lizard is inconspicuous in appearance. On numerous occasions, specimens would have been missed if they had not rustled leaves on the ground as they ran. Their movements are quick and jerky. When pursued ground skinks burrow into the leaf mold. They have been encountered at night several times. An ac- tive individual was once found in February. The food of the ground skink consists of small, soft-bodied arthropods. A captive specimen laid 5 eggs on June 21-22. At the time the eggs were laid, their dimensions averaged 8.6 X 5.1 mm. In a few days the average size was 8.6 X 6 mm., but the eggs spoiled soon thereafter. Eggs in natural nests have been found in rotten logs in July. Hatchlings are abundant by late August. Illinois Distribution.—The ground skink is abundant in wooded regions of the Shaw- nee Hills and Lower Mississippi Border counties, fig. 154. Widely scattered colonies Vol. 28, Art. 1 int Ml. Ahi ae AI i il ; wl rl ‘i y ¢ te Y Fig. 154.—Distribution of Scincella laterale. Hatching indicates the presumed range of the species in Illinois; solid circles indicate locali- ties represented by specimens examined during this study; the open circle indicates a locality represented by a published record believed to be valid. The lower map depicts the total range of the species in the United States. are known as far north as Calhoun and Cumberland counties; numerous areas be- tween, which appear to be suitable, are seem- ingly uninhabited. The northern colonies are in dry, wooded habitat; rocks are not requisite for the occurrence of Scincedla. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: WaBASH County: Mount Carmel (Cope 1900). Eumeces Wiegmann Fourteen species of this genus, a few con- sisting of several subspecies, occur in the United States and Canada. The genus is al- most world-wide in distribution. Two spe- cies are known to inhabit Hlinois and two others may eventually be found in the ex- treme western part of the state. : : ) | | : | | | | November, 1961 SmitrH: AMPHIBIANS AND REPTILES OF ILLINOIS Fig. 155.—An adult female Eumeces fasciatus from Monroe County, Illinois. Young speci- mens are black with narrow yellowish white lines and brilliant blue tails; subadult males and adult females are dark brown with light gray stripes. Adult males are bronzy brown with little trace of the striped pattern and have conspicuously reddened jowls. Eumeces fasciatus (Linnaeus) Five-Lined Skink Lacerta fasciata Linnaeus 1758:209 (type lo- cality: Carolina; revised to Charleston, South Carolina, by Schmidt 1953). Plestiodon fasciatum, Kennicott 1855:591. Eumeces fasciatus, Schneck 18800:55. Plestiodon quinquelineatum, Kennicott 1855: DOT. Eumeces quinquelineatus, (?part). Eumeces sp., Mertens 1951:15. Cope 1900:639-40 Diagnosis.—A small to medium-sized liz- ard (largest Illinois specimen 190 mm. in total length), fig. 155, with 26 to 30 smooth, subequal scales around the mid-body; 50 to 54 dorsal scales between the occiput and a point above the hind legs; frontal scale rec- tangular; pattern of 5 longitudinal light stripes on dark background, except in sexu- ally mature males, which are tan, gray, or bronze, with red jowls; juveniles and sub- adults with blue tails; two postmental scales and a postnasal scale on each side of head; usually 7 + 7 supralabials; 2 subequal post- labials, fig. 146. Key characters of this species and a similar species, Eumeces lati- ceps, are graphed in fig. 156. Variation.—The adult male in this spe- cies is almost unicolorous above, with red or coppery color on the swollen jowls; the adult female retains the striped juvenile pattern, although the lines are often dim. The base of the tail and the temporal region are con- spicuously larger in the male. Newly hatched skinks are shiny black, with distinct light stripes and a brilliant blue tail, which is proportionately shorter than in adults. The subadult loses the blue color of the tail and much of the contrast between stripes and groundcolor. Individual variation within a series from one locality at least equals any geographic variation in Illinois. Scutellation data for two samples are summarized in table 45. A Eumeces fasciatus o @ Eumeces laticeps sal < AABLAAADAALALAACC® a) AAAAALA® ee os AAAAA inl RASA AOA & AASAA a AAA gn e°o Ome ) @ @e@e0e6 eal | e Dee eoec5e oO, e©e0e80 = eceoeeeceeod z Vien d t= 6 S=-8 NUMBER OF SUPRALABIALS Fig. 156.—Scattergram showing number of supralabials plotted against number of post- labials in Eumeces fasciatus (hollow symbol) and Eumeces laticeps (solid symbol). Habits.—The five-lined skink is often seen on sunny days around abandoned build- ings, rotten logs, dead trees, and rock out- crops, but it can be collected in numbers only by raising rocks or logs, or ripping apart rotten stumps. The species is much less conspicuous than the northern fence liz- ard. The two species are equally abundant in the southern half of Illinois. Both open and dense wooded areas appear to provide ideal habitat for five-lined skinks. ‘These 170 Table 45 -—Geographic variation in Illinois Eumeces fasciatus. numbers of specimens. CHARACTERISTIC Scale TOWS SEE -OOM ie oa eas bese soko ste es bs DGrsdl Scaleiro ws et. ane ots iis a ioe pei stone Subdigital lamellae on fourth toe................ Snout-vent lenrth (MN). ¢S50.. 6a vk ees ones Total length (mm.), maximum.................. skinks are quick and difficult to capture, but usually they are not so alert as fence lizards. Captured specimens try to bite, and often their tails are broken off unless the animals icp ll i Mi il ey ear =i hl Ba ma i ae Van pil 0 Fig. 157.—Distribution of Eumeces fasciatus. Hatching indicates the presumed range of the species in Illinois; solid circles indicate locali- ties represented by specimens examined during this study; the open circle indicates a locality represented by a published record believed to be valid. The lower map depicts the total range of the species in the United States. The species avoids prairie areas. Ittinoris NaturAL History Survey BULLETIN Vol. 28, Art. 1 Figures in parentheses are SOUTHERN bBo I_trnors NortH Ittinots (20) cere Range | Mean | Range | Mean eer 25-30 28.9 26-30 28.4 Pee 5 We 50-55 52.9 52-55 53.0 Petites 15-19 16.8 15-18 16.6 ice capiey 34.0-82.8]... ... 0/3500] eee Be teere te 195 12.0 ee 187A a one are handled carefully. The food of these skinks consists primarily of arthropods, al- though instances of predation on annelids, mollusks, and vertebrates have been re- ported. Egg clutches of the five-lined skink, at- tended by the female, are to be found in rot- ten logs or stumps in July. Eggs laid by a captive specimen averaged 13 X 7.8 mm.; the eggs increase in size as they develop, and those found in natural nests average 13.5 X 10 mm. The clutch size in southern Illinois ranges from 6 to 15, averaging about 9 per nest (Cagle 1940). Oviposition occurs in late June, and hatchlings are to be found by late July. Illinois Distribution——The _ five-lined skink occurs throughout the southern half of Illinois, fig. 157. It is known in the Northeastern Mesic Forest, and scattered colonies may occur along the Mississippi and Illinois rivers. North of the Shelby- ville Moraine this species is very rare and probably does not occur at all throughout the Grand Prairie region. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: LAKE County: Waukegan (Cope 1900). Eumeces laticeps (Schneider) Broad-Headed Skink Scincus laticeps Schneider 1801:189 (type locality: not stated; designated as Charles- ton, South Carolina, by Schmidt 1953). Eumeces laticeps, Taylor 1935:212-24. Plestiodon quinquelineatum, Kennicott 1855: 591 (?part). Eumeces quinquelineatus, (?part). Cope 1900:639-40 November, 1961 Eumeces fasciatus mec Linnaeus, Yarrow 1882a:42 ( ?Ppart). Eumeces obsoletus nec Baird & Girard, Davis & Rice 1883a:31. Scincus erythrocephalus, 257-9 (?part). Eumeces sp., Mertens 1951:15. H. Garman 1892: Diagnosis.—A large skink (largest IIli- nois specimen 260 mm. in total length), fig. 158, differing from the five-lined skink in the usual presence of 8+ 8 supralabials (usually 5 preceding subocular), 1 + 1 post- labials, fig. 144, slightly higher average num- ber of scale rows at mid-body, and _ its larger size. Variation.—Sexual and ontogenetic vari- tion in Eumeces laticeps parallels that in E. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 171 fasciatus. Scutellation data for three sam- ples are summarized in table 46. Habits.—This large Illinois skink is sim- ilar in habits to E. fasciatus. It is reportedly more arboreal, however, and the Illinois ob- servations bear out the report. It is occa- sionally seen high in trees, particularly in dead trees with numerous woodpecker holes. On the ground it is agile and quick. Captives are quick to bite, and their jaws are strong enough to inflict an uncomfort- able pinch. Specimens have been observed at the edges of wood lots, where they were feeding on grasshoppers. These lizards prob- ably feed on almost any animal they can overpower. fi VA Fig. 158.—An adult male Eumeces laticeps from Coles County, Illinois. Young specimens are black with yellowish white lines and blue tails; subadult males and adult females, dark brown with light gray stripes; adult males are bronzy brown with little trace of the striped pattern and have conspicuously reddened jowls. Table 46.—Geographic variation in Illinois Eumeces laticeps. Figures in parentheses are numbers of specimens. Becahiare SouTHERN ILL1- SOUTHERN aoe Nea Oe Rock @ Iuiinors (12) ee IsLAND HARACTERISTIC Hits (21) Connae(l) Range Mean Range Mean Mueale rows at mid-body.........<....00000:: 27-32 2955 27-33 29755 30 BEANE RAWS ols.o a5 scaccipihit os boa eee dao 50-56 53a1 51-55 52.4 56 Subdigital lamellae on fourth toe............ 16-18 Weil 15-18 16.6 17 maout-vent length (mm.)..............2.:..- A) 59/0 eee eet Boe OMG e Ole o1 14. 64 Total length (mm.), maximum............-.. DOS al San hela. DOOM erro orcis ltteer sh sek ters 172 Almost nothing is known of the nesting habits of the species in Illinois. A female was found coiled around her eggs in a stump on July 4; the eggs were not measured. Illinois Distribution.—The broad-headed skink, like E. fasciatus, is common through- out the southern half of Illinois, fig. 159, ‘Higa Hit ilk i ce be ip ‘i a sil mt ppl is wii ! a WC is il Fig. 159.—Distribution of Eumeces laticeps. Hatching indicates the presumed range of the species in Illinois; solid circles indicate locali- ties represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. and extremely local in its occurrence north of the Shelbyville Moraine. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Cum- BERLAND County: SE corner of county (Peters 1942); Jackson County: Mur- physboro (Taylor 1935) ; RANDOLPH CouN- ty: Chester (Taylor 1935) ; Red Bud (Tay- lor 1935); Sr. Craik County: Belleville (Taylor 1935). Ituinois NarurAL History SurvEY BULLETIN Vol. 28, Art. 1 Eumeces anthracinus pluvialis Cope Southern Coal Skink Eumeces pluvialis Cope 1880:19, footnote (type locality: near Mobile, Alabama). Eumeces anthracinus pluvialis, Smith & Smith 1952:690. Diagnosis.—A medium-sized skink with a single postmental scale, fig. 143; 23 to 30 rows of smooth scales at mid-body; usually 7+ 7 supralabials; supranasal scales pres- ent but no postnasal scales; a distinct black or chestnut dorsolateral stripe on each side of body. Range.—The southern coal skink is known in Missouri adjacent to Monroe County, Illinois, but efforts to secure speci- mens on the Illinois side of the Mississippi have thus far been unsuccessful. There is a possibility that a local population in the IlIli- nois bluffs may eventually be found. Eumeces septentrionalis septentrionalis (Baird) Northern Prairie Skink Plestiodon septentrionalis Baird 1858:256 (type locality: Minnesota and Nebraska; revised to Fort Ripley, Minnesota, by Schmidt 1953). Diagnosis.——A medium-sized skink with supranasal but no postnasal scales, fig. 145; two postmental scales; 26 to 28 rows of smooth scales at mid-body; conspicuous, light, dorsolateral stripe on each side of body bordered above and below by prominent, slightly wider dark bands; dim or prominent light middorsal line that does not fork. Range.—The northern prairie skink is known from nearby Iowa and Wisconsin, and there is some possibility that popula- tions occur in the northwestern corner of Illinois, in which little work has been done. Suborder SERPENTES Snakes Forty-six species and subspecies of snakes are known to occur in Illinois. Four of the species are represented not only by a popula- tion typical for a particular subspecies but by an adjacent intergrade population as well. Although these intergrade populations are not regarded as distinct entities they are in- cluded in the key. Snakes are extremely variable in habits and structure. In general, the crotalids November, 1961 (Crotalus, Sistrurus, and Agkistrodon) and natricines (Natrix, Thamnophis, Storeria, Virginia, and Tropidoclonion) are active day or night, and the colubrines (the remaining genera) tend to be diurnal. The majority of our genera are terrestrial; some are fos- sorial; a few are aquatic; still fewer are arboreal. In size, they range from the 10- inch Tantilla gracilis to the 7-foot Pituophis melanoleucus. Snakes are rather specialized in feeding habits, some taking only one or two specific types of prey. All of them are predatory. Some species swallow living prey; some swallow their prey after killing it by constriction and some (those that pos- sess fangs) after using poison for procuring it. One or more species of venomous snakes occur in all herpetofaunal divisions of IIli- nois, but there are many smaller areas of the state from which the poisonous snakes have been entirely eliminated. The danger- ous species rank, according to the decreasing seriousness of their bites, as follows: timber rattler, cottonmouth, copperhead, and mas- sasauga. Although bites of all four species have come to my attention in the course of this survey, I know of no deaths from snake bite in Illinois during this time. The cop- perhead is probably responsible for the great- est number of snake bites requiring medical attention. Snakes usually mate in the spring of the year, although exceptions are known. Ap- proximately half of the Illinois species lay elongate, membranous-shelled eggs; the other half retain their eggs within the body and give birth to active young. The former are called oviparous; the latter ovovivipar- ous. Typically, snake eggs are deposited un- der rocks or in wood rot. The hatching of the eggs of the oviparous species and the birth of young of the ovoviviparous species take place in late summer and early fall. The young snakes grow fairly rapidly and are probably sexually mature at an average age of 2 years. The young and adults shed their skins two to six times annually, the number of times depending on the rate of growth and state of health of the individual snake. Most of the species and subspecies found in the state have the centers of their ranges outside of Illinois. Seventeen have distri- butions centering to the west and southwest, SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 173 the ranges of some (for example, Tantilla gracilis) being slight eastern extensions of ranges in the Ozarks of Missouri and Ar- kansas. Others (for example, Heterodon nasicus) are Great Plains animals with small relict populations in our sand prairies. Eleven forms have essentially southern ranges with northward extensions in the Mississippi River valley. Eight have ranges centering to the east of Illinois and one to the north; eight cannot be readily assigned to any of the above groups. Key to the Suborder Serpentes (Snakes) 1. No pit between eye and nostril, figs. 160, 116i (Colubridaé) eee eee eee 7 Pit between eye and nostril on each side of head, fig. 163 (Crotalidae)....... 2 2. Rattle on end of tail.................. 3 Nowrattle on!’ tail em eee 5 3. Top of head with large plates......... Sistrurus catenatus catenatus Top of head with various-sized unsymmet- TICAleSCAleS rte ae ke eee 4 4. Dorsal scales usually in 23 rows; few or no elongated black dashes between body bands. Crotalus horridus horridus Dorsal scale rows usually 25; many elon- gated black dashes between body bands fe, Crot- alus horridus horridus X atricaudatus 5. Scale rows 23, fig. 162; suboculars present: postorbital dark stripe absent...... 6 Scale rows 25; suboculars absent; post- orbital dark stripe present......... _. Agkistrodon piscivorus leucostomus 6. Dorsal pattern constrictions averaging 3 scale lengths in width or less; ventral spots pale. A ghkis- trodon contortrix contortrix X mokeson Dorsal constrictions averaging 4 or 5 scale lengths in width; ventral spots in marked contrast to groundcolor. . Ae ae Agkistrodon contortrix mokeson 7. Some or all dorsal scales keeled... .8 All scalessmooth:..4) 2. +402 oe: 38 8. Anal plate divided, fig. 164.......... 5 Anal plate entire, fig. 165............ 31 9. Rostral scale upturned and keeled, figs. TMCS IN asco a ae fea col rte arth Re a pee catch oe 10 Rostral scale normal, fig. apne lee. 12 10. Prefrontals in contact, fig. 166; posterior supralabials slightly higher than wide Besa ec Oe ee Ree Heterodon platyrhinos Prefrontals separated by small scales, fig. 167; posterior ig es about twice as high as wide. Weta All 11. Dorsal body blotches usually more than 35 in males, more than 40 in females Piscine haar: Heterodon nasicus nasicus Dorsal body blotches usually less than 35 in males, less than 40 in females. Heterodon nasicus nasicus X gloydi 12. Loreal PLESENt UM Oa eLG Steere. eae et 1 Worealwlacking; tig 169 cess os 13 174 ROSTRAL INTERNASAL PREFRONTAL i saw PARIETAL Cl] 49 oe, Wo Sainwesy, PRR OZER Fig. 160.—Dorsal view of the head of a snake, Elaphe obsoleta. PREOCULAR = ie) SS ae De POSTERIOR x | Yan IPSS NASAL ‘.\;05 5: 21 21. Dorsal scale rows 25-27; pattern in adults of evident black blotches on gray groundcolor...Elaphe obsoleta spiloides Dorsal scale rows 25; pattern in adults solid black, or the groundcolor visible as tracery around blotches or as white patches between spots middorsally on the posterior portion of body.......... eRe We ot Elaphe obsoleta obsoleta 23 Scale rows more than 19.............. 25 23. Infralabials 7; preoculars 1 on each side of hewdy!. <2 4a se Natrix kirtlandi Infralabials 9 or more; preoculars 2 on each side of head. ...0...i50- eo eee 24. Venter immaculate yellow or with 1 thin median stripe...... ....Natrix grahami Venter entirely dark brown or with two median stripes... Natrix septemvittata SUPRAOCULAR POSTOCULAR Fig. 161.—Lateral view of the head of a snake, Elaphe obsoleta. C CS OK Bosceceeetacerers LEIA III LA SALAS Fig. 162—Portion of the body of a snake, illustrating method of counting scale rows. Counts are customarily made one head length behind the head, at approximately mid-body, and just in front of the anus. 25. Scale rows 27-33; infralabials 11 or more on each side of head Scale rows 25 or less; infralabials 10 on each side of head...............--- November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 175 26. Suboculars separating eye from labials; 28. Ventral color red or red-orange, not touch- venter predominantly dark, with light ing first scale rows; dorsum black... eA SEDER Biche Shy Se eA CATE Etc 2 ME ees Natrix erythrogaster neglecta - eae ee Natrix cyclopion cyclopion Ventral color yellow or orange-yellow, en- No suboculars, fig. 173; venter yellow, croaching on lowermost lateral scale metMdati SPOtS? i: 0. piss dek ls. rows; dorsum brownish black....... cae Natrix rhombifera rhombifera ..... Natrix erythrogaster flavigaster 27. Venter unmarked, yellow or red. ...28 29. Dorsal bands fewer than 20......__. : Venter marked with brown or black spots © .............. Natrix sipedon confluens Ormeblotches ja... 5. cictae Veale eos 29 Dorsal bands 20 or more............. 30 SE a 29 SS i t CF Pee A Figs. 163-173.—Characteristics of snakes: 163, head of Agkistrodon piscivorus, showing loreal pit; 164, divided anal plate; 165, entire anal plate; 166, head of Heterodon platyrhinos ; 167, head of Heterodon nasicus; 168, head of Virginia valeriae, showing elongate scale between eye and nostril that is termed loreal because its length is twice its height; 169, head of Storeria dekayi; 170, head of Opheodrys vernalis; 171, head of Farancia abacura; 172, head of Natrix cyclopion, showing suborbital scales; 173, head of Natrix rhombifera. 176 30. 31. 33. 34. 38. = 40. 41. Ittinors Narurat History Survey BULLETIN Dorsal bands and spots 30 or more; lat- eral bars wider than interspaces; an- terior transverse bands 3 to 10 Bh See Gh REPRE Om ie Natrix sipedon sipedon Dorsal bands and spots less than 30; lat- eral bars narrower than interspaces; anterior transverse bands 5 to 15 Lotte Sesto Natrix sipedon pleuralis Scale rows 27 or more; prefrontals 3 or mpi 540%, Pituophis melanoleucus sayi Scale rows less than 27; prefrontals 2 32 Infralabials 8 or more on each side of head Infralabials less than 8 on each side of head Lateral stripe involving fourth scale row; parietal light spots usually present. .34 Lateral stripe not touching fourth scale row; no parietal spots. Supralabial sutures margined with black; tail length less than 27 per cent of total eR eee Thamnophis radix radix Supralabials uniform greenish white or yellow; tail length 27 per cent or more of total lengths. a8 ee : Groundcolor black, with orange middorsal and greenish white lateral stripes; su- pralabials usually 8 on each side _.. Thamnophis sauritus proximus Groundcolor dark brown, with orange or yellow middorsal and yellow lateral stripes; supralabials usually 7 on each side SP mE oe ah ark Tham- nophis sauritus sauritus X proximus Lateral stripes regularly interrupted on anterior third or fourth of body by black crossbars Thamnophis sirtalis semifasciata Lateral stripes uninterrupted by black crossbars...Thamnophis sirtalis sirtalis Dorsum and venter unmarked........... ere Virginia spp. (couplet 16) Dorsum with longitudinal light stripes; venter with a pair of longitudinal dark stripes or double row of spots......... .... Lropidoclonion lineatum lineatum Anal plate divided, fig. 164 Anal plate entire, fig. 165 Dorsal pattern of distinct dark blotches on light groundcolor ._...... 41 Dorsal pattern of white dots on black STOUNACOLOL= Mey oe coh ee ee Yellow spots on almost all dorsal scales a Sgt eth Lampropeltis getulus holbrooki Yellow spots few, tending to form rings around body Leena Lampropeltis getulus niger Venter unmarked; rostral plate with wartlike protuberance Cemophora doliata Venter with dim gray spots on greenish yellow groundcolor or with prominent black squares on a white groundcolor; rostral scale without protuberance. . .42 . Ventral spots gray and indistinct against the greenish yellow background; borders of dorsal blotches narrower than half a scale length at AC ane ee . Lampropeltis calligaster calligaster 43. 44, 45. 46. 47. 48. 49, 50. 51. 52. 54. 35: Vol. 28, Art. 1 Ventral spots black, in sharp contrast to the white groundcolor; dorsal blotches with black margins, each margin almost as wide as the length of one scale. 43 Dorsal blotches red, extending down sides to first or second scale rows, fewer than 35. ....Lampropeltis triangulum syspila Dorsal blotches brown, extending down sides to fourth or fifth scale rows, more than 35.0.5... <0) eee Lampropeltis triangulum triangulum Scale rows 19 or more; venter black, marked with transverse red bands .Farancia abacura reinwardti Scale rows fewer than 19; venter not black or marked with red bands 45 Neck with a yellow ring just behind head .. 46 Neck without “yellow ring behind head 48 Chin without black spots; venter immac- ulate or with an interrupted median row of black spots Diadophis punctatus edwardsi Chin with black spots; venter with scat- tered black spots or a continuous me- dian row of black spots... Venter with a median row of spots, often fused and forming a median stripe; us- ually 15 scale rows ; ee Diadophis punctatus stictogenys Venter with scattered black spots or sev- eral rows of spots; usually 17 scale fows «sass Diadophis punctatus arnyi Loreal present, fig. 168.22. pee 49 Loreal absent Tantilla gracilis hallowelli Preoculars 1 or more on each side of head’ ..e. 05003 Lo ae 52 Preoculars none ..................- 50 Scale ‘tows 13 ......0. 5 38eeee 5 Scale rows more than 13 Virginia valeriae elegans Dorsal color black; ventral color salmon, extending onte third scale row eae ..Carphophis amoenus vermis Dorsal color brown; ventral color salmon or pink, extending onto first or second scale rows Carphophis amoenus helenae Anterior temporals 1 on each side of head; color green above . ie ..Opheodrys vernalis blanchardi_ Anterior " temporals 2 or 3 on each side of head; color never green Scale rows at posterior end of body 13 or fewer. Masticophis flagellum flagellum : Scale rows at posterior end of body 15. 54° Back with 50 to 80 blotches, becoming ob-. scured posteriorly juvenile Coluber constrictor | Back unmarked, blue-green or blue- black | Caudals averaging less than 90; venter and chin pale yellow or light gray; dor- sum dark blue or blue-green Coluber constrictor flaviventris: Caudals averaging 90 or more; venter slate gray, chin white; dorsum blue-— black © 8) a. ee Col- f uber constrictor priapus X flaviventris November, 1961 COLUBRIDAE Thirty-eight genera of this large, wide- spread family occur within the United States and Canada. Seventeen genera are repre- sented in Illinois. Carphophis Gervais This genus consists of a ‘single species, which occurs only in eastern North America. Carphophis amoenus (Say) Three subspecies of worm snakes are recognized, two of which are found in IIli- nois. Carphophis amoenus helenae (Kennicott ) Midwest Worm Snake Celuta helenae Kennicott 1859:100 (type local- ity: Monticello, Mississippi). Carphophiops helenae, Cope 1875:34. Carphophis helenae, S. Garman 1883:101, 166. Carphophis amoena helenae, Bocourt 1883:536. Carphophis amoenus helenae, Perkins 1949:27. Celuta amaena, Kennicott 1855:592. Carphophiops amaenus, Surface 1906:134. Carphophiops amoenus, Cope 1875:34. Carphophis amoenus amoenus nec Say, H. Garman 1892:309-10. Carphophis amoenus, Boulenger 1894:325. Carphophiops amoenus amoenus nec Say, Cope 1900:736. Carphophis amoena, 8. Garman 1883:167. Carphophis amoena amoena nec Say, Jordan 19295235. Carphophiops 1877:64. vermis nec Kennicott, Copz SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS U7 Carphophis amoenus vermis nec Kennicott, H. Garman 1892:309-10. Carphoris vermis nec Kennicott, Hurter 1393: Zoe Diagnosis.—A small burrowing snake (largest Illinois specimen 309 mm. in total length), fig. 174, with smooth scales in 13 rows; ventrals 118 to 129 in males, 127 to 137 in females; caudals 32 to 40 in males, 24 to 27 in females; supralabials 5 + 5; in- fralabials 6 + 6; postoculars 1+ 1; a mi- nute, sharp spur on the tip of the tail; dor- sum brown; venter pink, the ventral color extending dorsad onto the lowermost one- half to 114 scale rows; internasals and pre- frontals fused into large plates (in 89 per cent, Blanchard 1924a); no preoculars. Variation.—In 26 specimens from which data were taken, the males possess 118 to 129 ventrals (average 121.8), 32 to 40 cau- dals (average 38.3); the tail comprises 16.9 to 19.9 per cent of the total length. Females have 127 to 137 ventrals (average 132), 24 to 27 caudals (average 26); the tail com- prises 10.7 to 14.8 per cent of the total length. Juveniles usually are more sharply bicol- ored than adults because of their darker brown or black dorsal color. No geographic and surprisingly little in- dividual variation in scutellation are evident in the 26 specimens studied in detail. Mean ventral and caudal numbers for samples from the Mississippi Border and Shawnee Hills differ by only 1 scale, despite the Fig. 174.—An adult Carphophis amoenus helenae from Union County, Hlinois. The color above is brown or black; below, pale pink to salmon color. 178 proximity of a Carphophis amoenus vermis population that has higher counts. All 26 specimens agree in the possession of 13 scale rows, 5+ 5 supralabials, fused prefrontal and internasals, and the absence of a preocular. The infralabial formula of 5 + 6 and the postocular formula of 1 +2 are each represented by single specimens, the remaining 25 snakes displaying formulae of 6+ 6 and 1 +1, respectively. In the Midwest worm snake, color and pattern are more variable than lepidosis. In the Lower Mississippi Border sample, the pattern appears somewhat more sharply bi- colored than in the Shawnee Hills sample, but the difference may be due to the greater number of juveniles in the specimens avail- able from the Mississippi River bluffs. The encroachment of the ventral color onto the lowermost scale rows is not correlated with geographical distribution. In samples of 13 specimens from the Lower Mississippi Bor- der and 13 from the Shawnee Hills, the same range of individual variation is exhib- ited. The ventral color extends onto half of the lowermost scale row on some specimens and onto the lower 134 in others, averaging 1.15 scales in each sample. Habits.—The Midwest worm snake is fossorial. In early spring it is found under rocks, logs, or the bark of stumps. As the ground becomes dry in summer, the worm snake seeks moist situations. This snake ap- pears temporarily dazed when first uncov- ered, but in a few seconds it becomes active, seeking to burrow into the soil. The writh- ing, hard, slick body is difficult to pick up, and even when captured this snake has a way of slipping between the collector’s fin- gers. It usually endeavors to press the tiny spur on the tip of its tail into the restrain- ing hand. The worm snake is known to feed on earthworms; it may possibly feed on soft- bodied arthropods also. Females collected in late spring contain two to four elongate, proportionately very large eggs. The eggs are probably depos- ited in hollows under large rocks or within hollow logs. Illinois Distribution—The Midwest worm snake occurs in abundance along the Mississippi River bluffs from Pike County southward and throughout the Shawnee Hills. Also it is known from scattered lo- calities in eastern Illinois, almost invariably in the vicinity of rock outcrops, fig. 175. Ittinoris NATURAL History SurRVEY BULLETIN Vol. 28, Art. 1 ee: 2S. SS ie Oe 1a. mee ee ee Fig. 175.—Distribution of Carphophis amo- enus. Vertical hatching indicates the presumed range of the subspecies helenae; horizontal hatching, the presumed range of the subspecies vermis; crosshatching, the area of intergrada- tion between the two subspecies; solid circles indicate localities represented by specimens examined during this study; open circles, local- ities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAcK- soN County: Murphysboro (Ditmars © 1945) ; Sr. Crain County: (Hurter 1893); — WasasH County: Mount Carmel (Cope ° 1877). Carphophis amoenus vermis (Kennicott) Western Worm Snake Celuta vermis Kennicott 1859:99 (type local- ity: Missouri). Carphophis amoena vermis, Langebartel 1947: 27-8. Diagnosis.—A subspecies of Carphophis — amoenus (largest Illinois specimen 285 mm. November, 1961 in total length) differing from C. a. helenae, by the more sharply contrasting purplish black dorsal color and the salmon-pink ven- tral color, the latter color extending dorsad onto the lowermost 114 to 3 scale rows; the usual presence of internasals; and the higher ventral and caudal counts. Variation.—Three specimens of the western worm snake are known from Illi- nois: a female with 140 ventrals, 24 cau- dals, ventral color extending onto 214 lower scale rows, and a tail length of 11.9 per cent of the total length; and two males with 135 and 127 ventrals, 38 and 39 caudals, ventral color extending onto the lower 1%4 and 214 scale rows, and tail lengths 12.1 and 17.0 per cent of the total lengths. All three speci- mens are purplish black above and bright pink beneath. All possess internasals. Other counts are the same as in helenae. Of the three Illinois specimens, the male from Calhoun County approaches helenae in its low number of ventrals. Otherwise, the two forms appear specifically distinct. Habits——The remarks concerning be- havior of C. a. helenae apply to this subspe- cies as well. No information on life history is available for the subspecies in II]linois. Fig. above is shiny blue-black; below there are bright red crossbands. SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 179 Illinois Distribution. — The western worm snake is known in Illinois only from Calhoun, Adams, and Hancock counties, fig. 175, all of which border the Mississippi River. The range of this race in the state is probably limited to these three counties, in- asmuch as C. a. helenae is known in the ad- jacent counties to the east and south. Farancia Gray One eastern North American species with two subspecies is included in this highly spe- cialized genus. One of the subspecies in- habits Illinois. Farancia abacura reinwardti (Schlegel) Western Mud Snake Homalopsis reinwardtii Schlegel 1837:173 (type locality: Louisiana; revised to vicin- ity of New Orleans by Schmidt 1953). Farancia abacura reinwardtii, Cagle 1941:20. Farancia abacura reinwardti, Schmidt 1953: 186. Farancia abacura, Cope 1877:64. Hydrops abacurus, 8. Garman 1883:36. Diagnosis.—A large aquatic snake (larg- est Illinois specimen 1,254 mm. in total 176.—An adult Farancia abacura reinwardti from Jackson County, Illinois. The color 180 Ittinors NaturAL History SurRVEY BULLETIN Table 47.—Sexual variation in Illinois Farancia abacura. numbers of specimens. Vol. 28, Art. 1 Figures in parentheses are CHARACTERISTIC length), fig. 176, lustrous blue-black above with 56 to 76 bright red transverse bars al- ternating with black bars beneath; red bars extending up onto lowermost scale rows; eyes degenerate; tail tip ending in a sharp spur; scales smooth, in 19 or 20 rows; ven- trals 167 to 194; caudals 36 to 49; supra- labials 7 + 7, sometimes 6 on a side; infra- labials 8 + 8, sometimes 9 on a side; post- oculars usually 2 on a side, sometimes | or none. Variation.—Sexual characters in Faran- cia are remarkably abundant. The male differs from the female in having a large, bulbar tail, conspicuous suranal zone of re- duced scales, and keels on the suranal scales. Other sexual variation is summarized in ta- ble 47. According to H. Smith (1938), the juve- niles are like the adults in details of color and pattern. Nonsexual variation illustrated by seven specimens is as follows: size range 762 to 1,254 mm.; scale rows 20-20-19 in one, 20-19-19 in three, and 19 in three speci- mens; supralabials 7+7 in five, 6+ 7 in two; infralabials 8+ 8 in three, 9+ 9 in four specimens; postoculars 1+ 0 in one, 1+ 1 in one, 1+2 in two, and 2+2 in three specimens; light, transverse body bars 48 to 64 (average 57); separation medially of neck bars 9 scale rows in one, 10 in one, and 11 in five specimens. Habits.—Shallow ponds and sloughs with many partially decayed and water-soaked logs provide ideal habitat for the western mud snake. Most of the Illinois specimens, however, have been found crossing roads on rainy nights. Although this species is known locally as the “stinging snake,” most resi- dents of southern Illinois do not seem to realize that this is the reptile presumably responsible for the “hoop snake” fable. A’ captured individual presses the sharp, horn- Paitit PAW Ie as oie or Seg AE a iiss ste neta ae a6 Tail length as percentage of total length.......... Mates (4) FeMa_es (3) Range | Mean | Range | Mean Tess BA 188-194 | 191.6 167-171 | 169.2 SOS ek 36-37 36.6 46-49 47.0 nines nuevehank 8-11 9.3 10-12 Mp bee Re sate 10.7-11.2| 11.0 |14.6-16.0} 15.2 Ye Qe eA ‘ a= aes A Tea eyeg fect Ae ala Fig. 177.—Distribution of Farancia abacura. Hatching indicates the presumed range of the subspecies reinwardti in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. like scale on the tip of the tail into the col- lector’s hand; this defensive mechanism is more startling than painful. Cagle (1942a) reported that a captive ate Siren. The spe- cies is known to feed on tadpoles and Am- phiuma. Cagle (1942a) had a captive female that — coiled about her 22 eggs laid on wet wood November, 1961 rot in early July. The irregular, flexible eggs, which averaged 34.5 X 19.9 mm., hatched in mid-August, after an incubation period of 41 days. Illinois Distribution——This southern species is characteristic of the swamps of the Austroriparian division, fig. 177. It is found in vegetation-choked ponds and flood- plain swamps in the Shawnee Hills area, also. The occurrence of this snake in the Wabash River valley near Mount Carmel has not been substantiated with recent col- lections, and Farancia may have been ex- terminated in that part of the state. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: PERRY County: (Cagle 1942a); WapasH Coun- ty: Mount Carmel (Cope 1877). Diadophis Baird & Girard Three species, each with several subspe- cies, of this North American genus are known. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 181 Diadophis punctatus (Linnaeus) Five subspecies of the eastern ringneck snake are recognized; three meet and inter- grade with one another in Illinois. All are similar above, fig. 178. Diadophis punctatus arnyi Kennicott Prairie Ringneck Snake Diadophis arnyi Kennicott 1859:99 (type lo- cality: Hyatt, Anderson County, Kansas) ; Cope 1875:38. Diadophis punctatus arnyi, S. Garman 1883: 158. Diadophis regalis arnyi, Cope 1900:746. Diadophis punctatus arnyi X stictogenys, Min- ton & Minton 1948:382. Diadophis punctatus nec Linnaeus, Stejneger & Barbour 1917:76. Diadophis regalis nec Baird & Girard, Dit- mars 19223272. Diagnosis.—A relatively small burrow- ing snake (largest Illinois specimen 370 mm. in total length), with 15 to 17 rows of smooth scales at mid-body; dorsum slate, blue-black, or brownish black; venter yel- Fig. 178.—An adult Diadophis punctatus edwardsi from Efhngham County, Illinois. In all Illinois subspecies of D. punctatus, the color above ranges from slate gray to blue-black; below the color is yellow or orange-yellow. The ring around the neck is yellow. 182 low or orange-yellow; a distinct, narrow yellow ring across the neck above; chin dark spotted; venter with scattered dark spots or transverse dark markings; ventrals 149 to 160 in males, 165 to 173 in females; ven- trals minus caudals 100 to 110 in males, 121 to 132 in females; supralabials usually 7+7. Variation.—In Diadophis punctatus arn- yi, the male differs from the female in hav- ing a higher caudal count, lower ventral count, and smaller difference between ven- trals and caudals, table 48. Many males (38 Ittinors NaTrurAL History Survey BULLETIN Vol. 28, Art. I per cent in Illinois) have keels on the scales just above the anus. Juveniles tend to be darker above than adults. Single individuals from Carroll and Rock Island counties and a sample of nine speci- mens from Hancock County are assignable to arnyi. These specimens are at variance with more western specimens in the heavy black spots on the chin and venter, but the increased amount of black in no way sug- gests intergradation with eastern subspecies. The major geographic variation in this subspecies is summarized in table 48. Table 48.—Geographic variation in Illinois Diadophis punctatus arnyi and D. p. arnyi X edwardsi intergrades. Figures in parentheses are numbers of specimens. | sree Con “i | Keanoou PE OUNTIES Cuanacrenistic SFewaes) | 14Fewares) | GL Mates, : 11 FEMALEs) Range | Mean | Range | Mean | Range | Mean Ventrals I" LAS ci nee RE: deen ie Pv 149-160 | 154.8 | 143-154 |! 148.0 | 147-159 | 151.2 RAM ieee Sh ss hoe ay Hee 165-173 | 170.0 | 150-159 | 156.6 | 147-165 | 160.0 Caudals Rage re a hea oe eee 46-58 50.2 41-52 49.0 40-51 46.2 Beet aM ct oes oe ein + Sica, 9 8 40-44 42.2 37-46 41.5 39-48 43.1 Ventrals minus caudals Males cite tent one 2) cattle Let ee ees 100-110 | 104.6 94-113 | 102.1 98-113 | 104.9 Hehe eins cat ceueees . eaRes 121-132 | 127.7 | 110-121 115.1 100-122 | 115.2 Tail length as percentage of total length WEAN eek on 5 has OC Reh aien mae 20.6-21.7| 21.1 |17.3-21.9| 20.6 |17.3-27, 32 | LES 1S ng A RON RR ae 16.2-17.3} 16.6 |14.5-19.5| 16.7 |15.8-19.8 17.1 Voul Jencth (aimee sooo t. i aecsuauie cs iy ett 6 eee 109-320 |......+s Per CENT OF Per CENT OF Per CENT OF SPECIMENS SPECIMENS SPECIMENS Gina spotted ae cts hire «tne ok ad 6 100.0 81.5 95:5 Ti IKSUPLAlA DIANS oem, here ie « Sommers ee 100.0 55.5 91.0 IS :scale rows at Mid-DOGY: 5-67. .4.. «3 2252 96.5 13.6 Venter plain or with median row of | | BDOES SEAS. tated feiaislecene hee aiea 11.0 DSS 9.0 ee November, 1961 Individual variation, which shows no geo- graphic correlation, for 58 specimens of arnyi and arnyi X edwardsi intergrades is as fol- lows: infralabials 8 + 8 in 76 per cent, 7 + 8 in 7 per cent, 7 + 7 in 14 per cent, and 8+ 9 in 3 per cent; preoculars 2 +2 in 98 per cent, 1+ 1 in 2 per cent; postoculars 2 + 2 in 92 per cent, 2+ 1 in 5 per cent, 1 +1 in 1.5 per cent, and 2+ 3 in 1.5 per cent. In the 39 specimens with arnyi-type ventral patterns, 82 per cent are irregularly spotted, 18 per cent have transverse bars. Habits.—The prairie ringneck snake is abundant under flat rocks on hill prairies and wooded bluffs during the spring and fall. In midsummer it seeks moist situations and Fig. 179.—Distribution of Diadophis puncta- tus. Vertical hatching indicates the presumed range of the subspecies edwardsi in Illinois; horizontal hatching, the presumed range of the subspecies arnyi; diagonal hatching, the pre- sumed range of the subspecies stictogenys; -crosshatching, the areas of intergradation be- tween subspecies; solid circles indicate locali- ties represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SmiITH: AMPHIBIANS AND REPTILES OF ILLINOIS 183 can sometimes be taken in numbers concen- trated in the vicinity of springs or in talus piles bordering low ground. Occasionally several snakes can be found under a single rock. When first uncovered they are tem- porarily dazed, but in a few seconds they scatter, often before they can be grabbed. Captured individuals do not bite but they excrete a foul-smelling substance. Many individuals curl their tails in corkscrew fashion, displaying the bright red color of the underside. The ringneck snake feeds on salamanders, arthropods, and_ earth- worms. Other small snakes have been re- ported as food items. The eggs of the western ringneck snake have not been found in Illinois. Ilinois Distribution.—D. p. arnyi is re- stricted in Illinois to the Mississippi River bluffs from Jo Daviess County to Adams County, fig. 179. Intergrade populations of edwardsi X* arnyi are known from Adams to Jackson counties along the Mississippi River. The influence of arnyi is exhibited only in the populations inhabiting the Mis- sissippi River bluffs proper. A few miles east of these bluffs, even in the same county, no evidence of intergradation can be dis- cerned. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: Han- cock County: Warsaw (H. Garman 1892). Diadophis punctatus edwardsi (Merrem) Northern Ringneck Snake Coluber edwardsii Merrem 1820:136 (type lo- cality: Pennsylvania; revised to vicinity of Philadelphia by Schmidt 1953). Diadophis punctatus edwardsii, Van Cleave 1928:133, 136. Diadophis punctatus punctatus nec Linnaeus, Davis & Rice 1883a:29. Diadophis punctatus, Cope 1900:753. Diadophis punctatus amabilis nec Baird & Girard, Davis & Rice 1883a:29. Diadophis punctatus arnyi nec Kennicott, Schmidt & Necker 1935:61. Diadophis punctatus strictogenys nec Cope, ?Cagle 1942a:186. Diagnosis.—A subspecies of Diadophis punctatus (largest Illinois specimen 346 mm. in total length), fig. 178, differing from D. p. arnyi in the usual presence of 15 scale rows at mid-body; chin usually without dark 184 spots; venter immaculate or with a median row of round dark spots; ventrals 138 to 147 in males, 151 to 160 in females; ven- trals minus caudals 85 to 98 in males, 102 to 114 in females; supralabials usually 8 + 8; underside of tail yellow. Variation.—Sexual and ontogenetic vari- ation in this subspecies parallel that shown by D. p. arnyi. Suranal keels are present on 43 per cent of the Illinois males available. Geographic variation in D. p. edwardsi is summarized in table 49. Individual, nongeographic variation is as follows: infralabials 8+ 8 in 41.7 per cent Table 49.—Geographic variation in Illinois Diadophis punctatus edwardsi. parentheses are numbers of specimens. WaBASH SHAWNEE GREENE-PIKE BorDeR Hits CounTIES (7 Males, (4 Mates, (5 MALEs, CHARACTERISTIC 6 FEMALES) 5 FEMALES) 4 FEMALES) Range | Mean | Range | Mean | Range | Mean Ventrals Males inti tno ate te veers ee 138-146 | 142.8 | 143-147 | 144.7 | 139-150 | 144.6 Hemaler ss tae she ees SOM eee 140-157 | 149.4 | 151-160 | 154.6 | 147-158 | 152.5 Caudals Bier Mats CARR ee one 47-56 50.8 47-51 49.0 47-50 48.7 Bemiglers) ai Veit hoe eine 43-54 48.8 46-49 47.6 38-45 41.5 Ventrals minus caudals Dale a 2s cas es ect eae ko ek en ae 139-165 | 156.0 153-171 | 159).2 154-157 | 155.6 Caudals | Wale sot erse cl Sunree eae 126-152 | 133.4 | 122-137 | 131.3 | 119-133 | 1241 | Bemales eee eee 116-132 | 126-1 116-133 | 123.3 121-128 | 123.2 Tail length as percentage of total length Mole ae ree tee 35.4-45.4] 39.4 |36.8-41.3| 39.9 [36.4-38.2] 37.3 Remalencas key ae eS 34.4-40.1| 37.1 |32.7-41.3} 35.5 \33.8-37.2 35.8 Tota) leneth mii.) ia ge so ese 1S R=847 alee gee V82=836 |e ee 213-684 |..... 0am November, 1961 cent of total length. Fifteen adult female specimens possess 116 to 133 caudals (aver- age 123.3) and 152 to 171 ventrals (average 159.1); tail length ranges from 32.7 to 40.0 (average 36.5) per cent of total length. Juveniles are proportionately larger headed, shorter tailed, and (in preservative ) more sharply bicolored. For five juvenile females the tail length averages 34.7 per cent of total length, for four juvenile males 36.3 per cent. Some geographic variation in the degree of sexual dimorphism in the rough green snake is suggested by a comparison of the means of ventral and caudal counts and ratios of tail length to total length for three samples from extreme southern Illinois, southeastern Illinois, and the Lower Missis- sippi Border. In females a slight reduction in the number of ventrals and caudals and proportionate tail length can be discerned from east to west; in males the trend is con- siderably more pronounced. This variation and the size ranges are summarized in table : 54. : Other variation in scutellation seems to _ be individual, although the presence of 2 postoculars tends to be more frequent in | eastern specimens than in others. Fifty- three specimens show the following variation in head scutellation: supralabials 7 + 7 in 51, 7+8 in 1, and 6+7 in 1; infralabials 8+ 8 in 47, 7+ 8 in 5, and 6+6 in 1; preoculars 1 + 1 in 40,2+2 in 9, and2+ 1 in 4; postoculars 2+ 2 in 47, 1+ 2 in 2, 1+ 3 in 1,1-+1 in 1, and 2+ 3 in 2. _ Habits.—The rough green snake is arbo- _ real and is seen most often in bushes and _ vines. It is most easily found in vegetation | overhanging streams or lakes, particularly _ after summer showers. The green snake is | nervous and quick. Newly captured individ- | : uals often open their mouths wide, exposing the purple mouth cavity. Despite its threat- i ening behavior this snake does not bite. Its ' food consists of various soft-bodied arthro- | pods, insects, and spiders. | The species is oviparous. A clutch of six elongate eggs was once found under a flat rock. No other life history information is . | available for the green snake in Illinois. | Lllinois Distribution.—The rough green snake, a forest-edge species, is more com- mon in the southern half of Illinois than is _ indicated by the available specimens, fig. 185. In central Illinois it. is abundant north to SmiTH: AMPHIBIANS AND REPTILES OF ILLINOIS 193 bs Fig. 185.—Distribution of Opheodrys aesti- vus. Hatching indicates the presumed range of the species in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, published records believed to be valid. The lower map depicts the total range of the species in the United States. the Shelbyville Moraine, where its range ceases abruptly. In extreme eastern Illinois and along the Mississippi River, apparently suitable habitat extends considerably farther north than the known range of the species. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAcK- son County: 4 mi. W Murphysboro (Min- ton & Minton 1948); St. Craik County: Mascoutah (Hurter 1893); Union Coun- ty: Anna (H. Garman 1892). Opheodrys vernalis blanchardi Grobman Western Smooth Green Snake Opheodrys vernalis blanchardi Grobman 1941: 11 (type locality: Spanish Peaks, Colorado) ; Cagle 1941:22. Opheodrys vernalis vernalis X blanchardi, Grobman 1941:17, 20. 194 ILttino1is NaturAL History SurRVEY BULLETIN Vol. 28, Art. 1 Fig. 186.—An adult Opheodrys vernalis blanchardi from Livingston County, Illinois. The color above is bright or dull green; below, white. Chlorosoma vernalis, Kennicott 1855:592. Cyclophis vernalis, Davis & Rice 1883a:29. Contia vernalis, Boulenger 1894:259. Liopeltis vernalis, Cope 1900:783. Eurypholis vernalis, Schmidt & Necker 1935: 68. Entechinus vernalis, Pope 1937:216. Opheodrys vernalis, Necker 1938:2. Diagnosis.—A small green snake (larg- est Illinois specimen 565 mm. in_ total length), fig. 186, with 15 rows of smooth sales around the body; ventrals 127 to 150; caudals 71 to 91; supralabials 7+ 7; infra- labials usually 7 + 7; preoculars 1 or 2, and postoculars 2 on each side. Variation.—In this subspecies the male has a higher caudal count and a longer tail but fewer ventrals than the female. Twen- ty-two male specimens have 127 to 140 ven- trals (average 132.6) and 79 to 96 caudals (average 87.6); the tail length ranges from 24.5 to 36.5 (average 32.2) per cent of total length. Twenty-seven females have 134 to 150 ventrals (average 145.1) and 71 to 86 caudals (average 78.6); the tail length ranges from 23.7 to 30.9 (average 27.7) per cent of total length. Newly hatched green snakes are dark olive-green. The slightly older juveniles are gray-green. Necker (1939a) reported buff- colored anomalies in yearling snakes. Young specimens are proportionately larger headed and shorter tailed than adults. The onto- Table 55.—Ontogenetic variation in propor- tionate tail length in three size classes of Illinois Opheodrys vernalis. Figures in paren- theses are numbers of specimens. Tait Lenctu as Per Centr oF TotaL LENGTH Tota LENGTH (Mm.) Male Female Under 200.........- 30.6 (10) | 26.7 (11) DOO=AOO: nee eee 33.1 (7) 28.5 (7) Over 400........... 34.1 (5) 28.7 (7) Table 56.—Geofgraphic variation in Illinois Opheodrys vernalis. Figures in parentheses are numbers of specimens. NorTHEASTERN ILLINOIS (13 Mates, CHARACTERISTIC 8 FEMALES) Range | Mean Ventrals Blecr ied Ads ee 27135) | 322 Hemmled Gucocc ck sks 139-149 | 144.0 Caudals Wialee iar eras tas: 79-89 85.0 Hemaless ie% so isiccaep ee 72-82 76.0 NorTHWESTERN East-CENTRAL ILLINOIS ILLINOIS (1 Mate, (8 Mates, Manion 13 FEMALES) 12 Fema_es) Countr ee nai (1 FEMALE) Range Mean Range Mean ISOM ali cai 127-140 |.133.8° *|. ..iceeeeeeee 134-147 | 142.6 143-150 | 146.7 149 Li Pies a a ss 79-96 91.1. |..2. 22 ce 71-82 FLAS: 76-86 80.6 79 November, 1961 genetic variation in proportionate tail length is summarized in table 55. The most notable intrastate variation in Opheodrys vernalis is the smaller number of caudals in males from northeastern IIli- nois than in those from elsewhere in the state. In this regard the northeastern IIli- nois population approaches the nominate race; it was, in fact, regarded as an inter- grade population by Grobman (1941). However, the females from this part of the state have caudal counts more or less typi- cal of blanchardi, and the ventral counts of all the Illinois green snakes suggest blanch- ardi. Geographic variation within the state in number of ventrals and caudals is sum- marized in table 56. Geographic variation in this species is rather unique. The two subspecies of O. vernalis are extremely similar morphologi- cally, differing only in averages of a few characters. The two races, nevertheless, ap- pear to be distinct biological entities, one oc- cupying a grassland habitat in the west and the other inhabiting forest in the east. More- over, despite their slight differences, they seem to be incipient species; in much of the area presumed to be intergrade in nature, the species is extinct or is known from rela- tively few scattered relicts. Thus, free inter- breeding probably does not occur in a large part of the area where bdlanchardi and the nominate race presumably are in contact. The northeastern Illinois population, which shows some influence of vernalis, is actually part of a continuous blanchardi population but is separated from the closest continuous population of vernalis by a hiatus of proba- bly 200 miles. Individual variation in other features of scutellation in 49 Illinois specimens are as follows: scale rows 15 throughout in 98 per cent, 13-15-15 in 2 per cent; supralabials 7+7 in 98 per cent, 7 +8 in 2 per cent; infralabials 7 + 7 in 51 per cent, 8+ 8 in 25 per cent, 7 + 8 in 14 per cent, 6+ 7 in 8 per cent, and 7+ 5 in 2 per cent; preoculars 1+ 1 in 61 per cent, 1 +2 in 22 per cent, 2+ 2 in 17 per cent; postoculars 2 +2 in 98 per cent, 2+ 1 in 2 per cent. In addition to buff-colored anomalies, Necker (1939a) reported a single blue ex- ample of the western smooth green snake. Habits.—The western smooth green snake is terrestrial; specimens are occasion- ally seen in low bushes and in grass. The SmiItH: AMPHIBIANS AND REPTILES OF ILLINOIS 195 most successful collecting method consists of raising pieces of ground cover, such as rocks, boards, paper, and other debris, and grab- bing the snakes beneath. This species is a prairie animal. Since destruction of much of the original prairie habitat, scattered colo- nies have been found mostly in wet meadows and vacant lots in suburban areas. ‘The green snake is rather slow in its movements and does not attempt to bite. Its food con- sists predominantly of soft-bodied arthro- pods. Stille (1954a) records the average clutch size for the Chicago region as about 6, with a range of 5 to 15 eggs. The individual eggs measure about 22 X 10.5 mm. In the Chi- cago area, oviposition occurs in mid-July, and a month is required for the eggs to Fig. 187.— Distribution of Opheodrys vernal- is. Vertical hatching indicates the presumed range of the subspecies blanchardi in Illinois; crosshatching, the area of intergradation be- tween the subspecies blanchardi and vernalis ; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. 196 Ittinois Narurat History SurvEY BULLETIN hatch. Eighteen eggs, laid by a large female in Champaign County on July 12, hatched on August 10. Illinois Distribution.—The present dis- tribution of the western smooth green snake, fig. 187, appears to be sporadic. In northern Illinois, colonies are often found in vacant lots, where individuals may be quite abun- dant. Toward the south, colonies become more widely scattered. Many of them have in all likelihood been exterminated within historic times as more and more prairie areas have been cultivated. There are valid records of the species as far south as Mar- ion, Madison, and Monroe counties, but no specimens have been taken in southern Illinois for many years. Although undocumented by _ specimens, published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: ADAMS County: (Grobman 1941); Cook Coun- TY: Berwyn, Beverly Hills, Elmwood Park, Evanston, Glencoe (Schmidt & Necker 1935); Harvey (Necker 1939c); Home- wood, Morgan Park, Park Ridge, Puring- ton (Schmidt & Necker 1935); Lake County: (Schmidt & Necker 1935); Mc- Lean County: Normal (H. Garman 1892) ; Mapison County: (Hurter 1903) ; Monroe County: (H. Garman 1892); Peoria County: Peoria (H. Garman 1892). Coluber Linnaeus A single species, with numerous subspe- cies, of this North American and Asiatic genus occurs in the United States and Can- ada. Coluber constrictor Linnaeus Eight subspecies of this wide-ranging spe- cies are currently recognized. Geographic variation in this species within Illinois is pronounced but distinctly clinal. Only one race and an intergrade population can be re- garded as occurring in the state, despite the many published reports of both the eastern black racer and the western blue racer. Racers from southern Illinois differ from those in central and northern Illinois in color, caudal counts, and relative tail length. Series from the southern part of the state are not typical of the eastern race constrictor or the Gulf Coast race priapus, but are more Vol. 28, Art. 1 or less intermediate between the western race flaviventris and either constrictor or priapus. Although they share with priapus the enlarged basal hooks on the hemipenes (and thus differ from constrictor), their pos- session of hemipenial hooks can be explained by regarding these snakes as constrictor X flaviventris intergrades, inasmuch as flavi- ventris also has enlarged hemipenial hooks. Despite two equally plausible interpretations on strictly morphological grounds, the south- ern Illinois racers are referred to C. c. flavi- ventris X priapus rather than to C. c. con- strictor X flaviventris to conform with the distributional relationships outlined by Auf- fenberg (1955). The resurrection of C. c. foxi Baird & Girard in the recent check list (Schmidt 1953) for the Prairie Peninsula racers is un- explained. In view of the almost identical scutellation of racers from northwestern Ohio, central Illinois, and Nebraska, C. c. foxi is almost certainly a junior synonym of flaviventris. Coluber constrictor flaviventris Say Eastern Yellow-Bellied Racer Blue Racer Coluber flaviventris Say 1823:185 (type local- ity: stone quarry on west side of Missouri River, 3 miles above Boyer’s River, Potta- wattamie County, Iowa). Coluber constrictor flaviventris, Ortenburger 1928:179. Coluber constrictor constrictor X flaviventris, Lueth 1941:29. Bascanion constrictor, Kennicott 1855:592. Bascanium constrictor, Yarrow 1882a:109-10. Bascanion constrictor constrictor nec Linnaeus, Davis & Rice 1883a:30. Coluber constrictor, H. Garman 1890:187. Coluber constrictor constrictor nec Linnaeus, Blanchard 1924b:536. Coluber constrictor foxi, Schmidt 1953:187. Diagnosis.—A moderately slender, large snake (largest Illinois specimen 1,535 mm. in total length), fig. 188, with 17-17-15 rows of smooth scales; ventrals 168 to 189; cau- dals 71 to 97; supralabials usually 7 + 7; infralabials 8+ 8; preoculars 2+ 2, the lowermost minute; postoculars 2 + 2; tem- porals usually 2-2-2 on each side; tail length 19 to 27 per cent of total length; adults uniformly blue-green, blue-black, or black above, yellowish white to dark slate color below; chin often conspicuously lighter than venter; juveniles blue-gray, with 55 to 87 red-brown dorsal blotches that become — November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 197 Fig. 188.—An adult Coluber constrictor flaviventris X priapus intergrade from Union County, Illinois. The color above may be blue-green, blue-black, or slaty black; below, yellowish white, pale gray, or slate color. indistinct posteriorly, venter with brown markings; each hemipenis with large basal spines. Variation.—Specimens of this species can be reliably sexed only by determining the presence or absence of hemipenes. “The mean difference between the male and the female in number of caudals and ventrals consists of only 3 or 4 scales. The juvenile is strikingly different from the adult, possessing reddish dorsal blotches that become progressively more closely crowded and more indistinct posteriorly. The tail is usually brownish gray, the venter speckled with brown, and the side of the head spotted with white. Individuals 500 mm. or more in length usually retain the blotches only on the anterior portion of the body. The ventral spotting usually persists in specimens 700-800 mm. in length, al- though these snakes are unicolorous above. The proportion of tail length to total length does not vary ontogenetically. Adult racers in extreme southern Illinois are usually blue-black above and slate color below, except for their conspicuously white chins, the edges of which are occasionally flecked with black. Occasional individuals Table 57.—Geographic variation from north to south in Illinois Coluber constrictor. Fig- ures in parentheses are numbers of specimens. EXTREME WeEsrt- Easrt- LoweER EXTREME NorTHERN CENTRAL CENTRAL MIsSISSIPPI SouTHERN Cc | Intrnors (15) | Intanors (15) | Iturors (15) Borper (15) Itumois (25) HARACTERISTIC | Range |Mean| Range |Mean| Range |Mean) Range (Mean; Range |Mean Wentrals........ 172-182 1176.7) 170-187 |176.5| 168-186 |179.1} 170-184 |176.2) 173-189 |178.7 audals........ 71-87 79.6) 76-89 83.6] 76-96 85.6) 82-95 87.7| 84-97 90.9 Tail length as | percentage of | total length. .|19.3-23.8 21.7/22.2-25.2| 23.81/20.2-26.1|] 23.5|19.8-27.3) 24.1|22.8-26.6] 24.4 198 Ittinors NaruraAL Hisrory SurvEY BULLETIN so colored occur in the Lower Mississippi Border division and Southern Division woodlands. In extreme northwestern IlIli- nois some racers have decidedly greenish dorsums and yellow throats. Over most of the state, however, these features are com- bined so that the majority of specimens are blue-black above and grayish white beneath. Juvenile racers in extreme southern IlIli- nois have fewer body blotches than those from the remainder of the state. Six juve- niles from the southernmost counties have 55 to 65 blotches (average 60); 15 juve- niles from central Illinois have 59 to 77 blotches (average 69) ; and 4 juveniles from the northernmost counties in the state have 60 to 72 blotches (average 67). In all Illinois specimens in which the hemipenes have been everted, basal hooks are present. The major geographic variation is sum- marized in table 57. Individual variation in other scutellation for 85 specimens is as follows: scale rows 17-17-15 in 81 speci- mens, 18-17-15 in 4; supralabials 7+ 7 in 71 specimens, 7 + 8 in 10, 8 + 8 in 3,6+6 in 1; infralabials 8+ 8 in 67 specimens, 8+ 9 in 9,9+ 9 in 7, 7+ 7 in 2; preocu- lars 2+2 in all; postoculars 2+2 in 84 specimens, 2 + 3 in 1. Habits.—The blue racer, although pri- marily terrestrial, does not hesitate to climb or to take to water when being pursued or when searching for food. It is frequently found under rocks or other objects, particu- larly when preparing to shed its skin or when temperatures are low. The racer is graceful, agile, and swift, and it is difficult to capture unless taken unaware. When cor- nered, it vibrates its tail, producing a rattling noise, and strikes savagely. Males report- edly may attack intruders during the mating season. Its food is remarkably varied, con- sisting of arthropods, annelids, amphibians, reptiles (even small turtles), birds, and mammals. In southern Illinois (Klimstra 1959c), its diet consists of insects (approxi- mately 39 per cent), small mammals (32 per cent), amphibians (11 per cent), reptiles (8 per cent), birds (6 per cent), and miscellane- ous items (4 per cent). In early spring, it feeds principally on mammals but from May through October subsists largely on insects. Captives are nervous, usually refusing food. Data presented by Cagle (1942a) and Pope (19444) indicate that the blue racer in Vol. 28, Art. 1 Illinois mates in May and early June. In late June and in July the 19 to 25 granular, white eggs are laid under rocks or within logs, and hatching occurs by early Septem- ber. Cagle found the average dimensions of eggs in southern Illinois to be about 24 X 19 mm. A clutch from central Illinois, how- ever, averaged 30 X 19 mm. The difference may be due to the different sizes and ages of the female snakes that laid the eggs. Illinois Distribution.—The blue racer is almost state-wide in occurrence in Illinois, fig. 189. Records are sparse in the heavily farmed muck prairie of northern and cen- tral Illinois and completely lacking in the northeastern corner of the state. In places throughout most of the state where the for- Fig. 189.—Distribution of Coluber constric- tor. Vertical hatching indicates the presumed range of the subspecies flaviventris in Illinois; crosshatching, the area of intergradation be- tween the subspecies flaviventris and priapus; solid circles indicate localities represented by specimens examined during this study; open circles, published records believed to be valid. There are small localized areas in the state where records are inexplicably absent. The — lower map depicts the total range of the species in the United States. November, 1961 est-edge habitat is widespread, racers are one of the most common large snakes. Coluber constrictor priapus X flaviventris intergrades occur throughout the southern part of Illinois. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: CHAm- PAIGN County: Urbana (H. Garman 1892) ; Cook County: Chicago (Yarrow 18822); Du Pact County: Hinsdale (Stille & Edgren 1948) ; KANKAKEE CouN- TY: Hopkins Park (Schmidt & Necker 1935); Knox County: Galesburg (H. Garman 1892); Macoupin' County: Standard City (Owens 1941); Prorta County: Peoria (H. Garman 1892) ; Un- 10ON County: Cobden (H. Garman 1892) ; Witt County: Birds Ridge (Stille & Ed- gren 1948). Masticophis Baird & Girard This genus is known from northern South America northward into the United States and reaches its greatest abundance in south- western United States and Mexico; four species, each with numerous subspecies, oc- cur in the United States. One of these spe- cies inhabits extreme southwestern Illinois. Masticophis flagellum flagellum (Shaw) Eastern Coachwhip Coluber flagellum Shaw 1802:475 (type local- and Virginia; ity: Carolina revised to SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 199 Charleston, 1953). Masticophis flagellum flagellum, Smith & Bur- ger 195021. South Carolina, by Schmidt Diagnosis.—A large, slender snake, fig. 190, usually with 17-17-13 rows of smooth scales; ventrals 186 to 207; caudals 91 to 119; supralabials usually 8 + 8; infralabials 10 + 10 or 11+ 11; preoculars 2 + 2; post- oculars 2 + 2; temporals 2-2 on each side; frontal almost twice as wide anteriorly as posteriorly; adults uniform black above and below anteriorly, becoming gradually lighter on the tail; tail red (in Illinois and Missouri) to tan; dorsum in juveniles yel- low-brown with dark crossbands, becoming indistinct posteriorly; venter in juveniles cream, with rows of brown spots; head in juveniles irregularly marked with white. Variation—F rom Illinois only two flat- tened specimens found dead on a road are extant. These were described (Smith & Bur- ger 1950) as follows: Both are juveniles, measuring 371 and 404 mm. in length. Scutellation is as follows: ventrals 207 and 200; subcaudals 95 and 91; scale rows 17-16-15 and 17-15-13. Sexual variation and ontogenetic variation in Masticophis are presumably similar to those of Coluber. Habits.—The eastern coachwhip is simi- lar to the racer, sharing many of the attri- butes described for that species, including its varied food habits. No information is available on the life history of the eastern coachwhip in Illinois. Fig. 190.—An adult Masticophis flagellum flagellum from Mayes County, Oklahoma. Examples from Illinois are jet black on the body with rose or tan increasing in extent toward the tip of the tail. (Photo by Isabelle Hunt Conant.) 200 Illinois Distribution——This species is known in Illinois only in the vicinity of Fults, Monroe County, fig. 191. Considera- ble field work along the west-facing Missis- Fig. 191.—Distribution of Masticophis flagel- lum. Hatching indicates the presumed range of the subspecies flagellum in Illinois; solid circles indicate localities represented by speci- mens examined during this study. The lower map depicts the total range of the species in the United States. sippi River bluffs has revealed only four in- dividuals, but additional specimens will likely turn up when the Lower Mississippi Border counties are more thoroughly col- lected. An adult seen alive could not be cap- tured. Another adult was found killed on the road, according to Douglas A. Rossman of the University of Florida (personal com- munication), but his specimen has not been available to me for scale counts. Elaphe Fitzinger Five species of Elaphe, most of them with several well-marked subspecies, occur in the United States and Canada. The genus is ILLINoIs NaTURAL History SurvEY BULLETIN Vol. 28, Art. 1 almost circumglobal in distribution; four species and subspecies inhabit Illinois. Elaphe guttata emoryi (Baird & Girard) Great Plains Rat Snake Scotophis emoryi Baird & Girard 1853:157 (type locality: Howard Springs, Ellis County, Oklahoma). ?Coluber emoryi, Cope 1875:39. Elathe emoryt emoryi, Wright & Wright 1952:585. Elaphe guttata emoryi, Schmidt 1953:196. Elaphe laeta laeta, Smith & Burger 1950:1-2. Diagnosis.—A large, moderately slender snake (largest Illinois specimen 1,172 mm. in total length), fig. 192, usually with 25- 27-19 or 25-27-21 rows of scales; ventrals 210 to 234; caudals 55 to 80; supralabials usually 8 + 8; infralabials usually 11 + 11; preoculars 1+ 1; postoculars 2+ 2; tem- porals 2-2 on each side; groundcolor gray, olive, or light brown, with 25 to 48 dark brown or red-brown quadrangular, black- bordered dorsal blotches; tail with 8 to 20 spots or crossbars; a pair of prominent brown processes extending from first dorsal blotch onto the head and uniting on the frontal plate; venter prominently checkered with black and white. Variation.— Males in this subspecies pre- sumably differ from females in the greater average number of caudals. A juvenile specimen from adjacent Mis- souri (Iron County) differs from adults pri- marily in the bolder pattern and in the lack of red or brown tint. The six Illinois specimens available vary as follows: total length 867 to 1,172 mm.; tail length 14.1 to 16.2 per cent of total length (average 15.0 per cent) ; ventrals 210 to 221 (average 215.6); caudals 55 to 67 (average 62.8); dorsal blotches 39 to 48 (average 43.3) ; tail rings 12 to 16 (average 14); infralabials 11+ 11 in three, 10 +11 in one, 9+ 9 in one, unknown in one. Two specimens are gray, prominently blotched with dark brown; four are decidedly red- dish in both groundcolor and color of blotches. Four specimens have 25-27-19 and two have 25-27-21 rows of scales. Four have 8+ 8 supralabials, one has 7 + 7, and one is too damaged to permit counting of supralabials. A specimen (INHS 6072) from Wayne County, Missouri, is 60 inches long, a foot longer than the largest previously recorded. SMITH: 1961 November, AMPHIBIANS AND REPTILES OF ILLINOIS 201 Fig. 192.—A juvenile Elaphe guttata emoryi from Reynolds County, Missouri. the blotches are red-brown to brownish black. color is gray or light tan; Habits.—The Great Plains rat snake, al- though more terrestrial in habits than most other members of the genus, has considera- ble ability in climbing. Its food consists of birds and mammals, which it kills by con- striction. Wild individuals vibrate their tails and strike, but captives are slow and even- tempered. The species is oviparous. known of its life history. Illinois Distribution.—F our of the speci- mens of this species extant from Illinois have been taken dead on the bluff road be- tween Valmeyer, Monroe County, and Prai- rie du Rocher, Randolph County. This road is bordered on one side by the heavily farmed Mississippi floodplain, on the other by dry, "precipitous rock bluffs. Two other speci- mens have been taken on the forested cam- pus of Principia College near Elsah. Neill | (19515) reported having seen a specimen | mear East St. Louis, St. Clair County. Ad- Bs ditional specimens may turn up in other | | Little else is ) Lower Mississippi Border counties, but it is unlikely that this western subspecies will be found elsewhere east of the Mississippi River, fig. 193. The ground- The ranges of Elaphe guttata guttata and E. g. emoryi do not meet, even though the two forms are currently regarded as sub- species of a single species. The old published records for guttata in the Wabash Border counties are almost certainly based on mis- identified specimens of the superficially simi- lar Lampropeltis calligaster, as has been sug- gested in the list of deleted species. The kin- ship of guttata and emoryi assumes that in- tergradation occurred formerly but that the intergrade populations have since disap- peared. The morphological relationship of these two subspecies, or incipient species, is obvious. The distributional relationships of emoryi focuses attention on another species of rat snake, E. vulpina, with similar habits and habitat requirements. These two species have more or less geographically complemen- tary ranges in western I]linois, Missouri, and Kansas. In fact, both are known in the same Illinois county (Jersey) from localities that are scarcely 15 miles apart. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Mapr- 202 Fig. 193.—Distribution of Elaphe guttata. Hatching indicates the presumed range of the subspecies emoryi in Illinois; solid circles indi- cate localities represented by specimens ex- amined during this study; open circles, locali- ties represented by published records believed to be valid. The lower map depicts the total range of the species in the United States; the dots in the hiatus represent guttata. son County: Alton (Smith & Burger 1950) ; Sr. Crarr County: vicinity of East St. Louis (Neill 1951). Elaphe obsoleta (Say) Eight subspecies of Elaphe obsoleta are recognized by some authorities, five by oth- ers. Two races are found in Illinois, inter- grading across the southern fourth of the state. Elaphe obsoleta obsoleta (Say) Black Rat Snake Pilot Black Snake Coluber obsoletus Say 1823:140 (type locality: Isle au Vache [sic] to Council Bluffs on the Missouri River; revised to Council Bluffs, Iowa, by Schmidt 1953); Jordan 1878:178. Coluber obsoletus obsoletus, Yarrow 1882a: 102. Elaphis obsoletus, H. Garman 1890:187 (part). Ittino1is NaturAL History SurvEY BULLETIN Vol. 28, Art. 1 Elaphis obsoletus obsoletus, H. Garman 1892: 290-1. Callopeltis obsoletus, Surface 1906:158. Elaphe obsoletus, Hankinson 1917:326. Elaphe obsoleta, Pratt 1923:218. Elathe obsoleta obsoleta, Blanchard 19246: 536. Coluber lindheimerii, Davis & Rice 1883a:29 (part). Elaphis obsoletus 1883:152. Coluber lindheimeri, Davis & Rice 1883b:36 (part). Elaphe lindheimeri, Wright & Wright 1952: 585. ?Coluber vulpinus nec Baird & Girard, Hay 1892a:499. ?Bascanion constrictor nec Linnaeus, Praeger 1899:597-9. Coluber obsoletus (part). lindheimeri, S. Garman confinis, Cope 1877:64 Diagnosis——A large, moderately stout- bodied snake (largest Illinois specimen 1,725 mm. in total length), fig. 194, with 23 to 27 rows of scales on the anterior part of body and 17 to 21 rows immediately preceding the anus, formula usually 25-25-19 or 25-27- 19; scales feebly keeled; head wider than neck; preoculars usually 1 + 1; postoculars usually 2+ 2; supralabials usually 8+ 8; infralabials 11 to 13 per side; anterior temporals 2 per side; ventrals 225 to 242; caudals 67 to 89. Adult pattern of speci- mens over most of state consisting of dark groundcolor on the dorsum, with milky white occurring as mottling in the inter- spaces between the almost obsolete dorsal blotches and as light-edged scales on sides of neck; venter yellowish white, checkered and stippled with black; juvenile pattern consisting of 28 to 40 dark, rectangular dor- sal blotches and 1 or 2 rows of alternating, dark lateral spots on a gray groundcolor; venter checkered with dark; tail 14 to 18 per cent of total length; ventral plates de- cidedly angular laterally. Variation.—Sexual dimorphism in this snake is illustrated by 16 males and 11 fe- males in table 58. The number of tail rings probably averages higher in males than in females. Juveniles of the black rat snake differ from adults only in distinctness of pattern, a difference sufficiently great to confuse one unfamiliar with immature rat snakes. The young are prominently blotched with dark on a groundcolor of white or gray. Fre- quently the anterior dorsal blotches are con- nected by lateral processes of the blotches, — and the lateral spots are usually linear on November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 203 ~ the neck. In northern specimens the top of frontal plates, a pattern that distinguishes the head is variously mottled, but in south- obdsoleta from all other baby rat snakes. erm specimens it is usually plain except for Four populations, differing strikingly in a prominent dark bar traversing the pre- color and pattern but with no correlated Fig. 194.—An adult Elaphe obsoleta obsoleta, blotched phase, from Cumberland County, Illinois. The groundcolor is gray or milky white, suffused with black; the square or quadrangu- lar blotches are jet black. Fig. 195.—An adult Elaphe obsoleta obsoleta, black phase, from Union County, Illinois. The color above is black; below it is pink or red, with black markings. | | 204 differences in scutellation, are discernible within the state. (1) Extreme southern IIli- nois snakes (Alexander and Union coun- ties) are intermediate in distinctness of pat- tern between the gray rat snake, Elaphe ob- soleta spiloides, and the darker pilot black snake, E. o. obsoleta, and they are accord- ingly regarded as intergrades. (2) Individ- uals from the Lower Mississippi Border are usually jet-black above, with little or no trace of blotches, fig. 195. The underside posteriorly is a uniform blue-black; ante- riorly the venter is usually pink or red, with black markings. (3) Specimens from the Mississippi Border between Monroe and Pike counties are exceedingly variable, rang- ing from the solid black phase just described to a conspicuously blotched pattern in which, however, the groundcolor is red, pink, or orange rather than gray. (4) Specimens from over most of Illinois (exclusive of the southern tip, the Lower Mississippi Border, and the Wabash and Ohio river counties) are black above, with definite light mottling at the points of the dorsal interspaces, fig. 194. The venter is yellowish white, with black markings. This fourth subrace is de- Ittino1is NaTurRAL History SurvEY BULLETIN Vol. 28, Art. 1 scribed in the paragraph on diagnosis. There is some indication that specimens from ex- treme northwestern Illinois may be lighter in color. Examples from Jo Daviess and Carroll counties exhibit a tendency toward dorsolateral stripes that are light colored. Except for the number of scale rows, which varies considerably among individuals, scutellation in EF. 0. obsoleta is remarkably uniform throughout Illinois. Toward the north there is a slight clinal reduction in number of ventral and caudal scales and a slight increase in the average number of body blotches. These gradients are sum- marized in table 59. Individual variation in the scutellation of 47 specimens of EF. 0. obsoleta and E. o. ob- soleta X spiloides intergrades is as follows: scale rows anteriorly 23 in 5 per cent of specimens, 24 in 7 per cent, 25 in 75 per cent, 26 in 2 per cent, 27 in 11 per cent; at mid-body 21 in 2.5 per cent, 24 in 2.5 per cent, 25 in 41 per cent, 26 in 7 per cent, 27 in 47 per cent; posteriorly 17 in 31 per cent, 18 in 5 per cent, 19 in 57 per cent, 21 in 7 per cent; supralabials 8 + 8 in 91.5 per cent, 9+ 9 in 6.4 per cent, 7 + 8 in 2.1 per cent; Table 58.—Sexual variation in Illinois Elaphe obsoleta. Figures in parentheses are num- bers of specimens. CHARACTERISTIC Wentrals 322 oiss iste oe aera ceieann cc eae eee Caudals Ast wetnbe PR se ear At eee Body-blotehies s:c5 54. ee eee Tail length as percentage of total length........... Mates (16) FemaLes (11) Range | Mean | Range | Mean 224-236 | 230.2 | 226-242 | 235.6 mee cat 77-89 81.6 67-77 73.4 Hikers Pe 28-40 32.0 24-35 30.2 PAs 15.7-18.4| 16.9 |14.4-17.3) 16.0 Table 59.—Geographic variation from north to south in Illinois Elaphe obsoleta obsoleta. Figures in parentheses are numbers of specimens. q | EXTREME Cent, Lower ALEXANDER- NorTHWESTERN Tuacuene MIssIssIPPi Union ILLINOIS (11 ohare BorDER CounTIES c SsTIC (3 Mates, ? (2 Mates, (7 Mates, aeaarate sg 3 FEMALES) 4 FEMALES) 5 FeMALeEs) 8 FEMALES) Range Mean Range | Mean Range | Mean Range | Mean [tet Tee een SLES —— Wentralsioccist screen. 996-938 .|-999.2 | 395-940 | 933.9 224-242 | 231.6 225-239 | 232.6 Caudals te Malev. 22ce% 79-85 S15) A oe 89 81.5 81-83 82.0 78-87 82.1 Female........ 67-74 70.0 TL Si 75.0 69-77 73.6 70-80 73.3 Body blotches...... 32-40 35.15 | 30-33 ope! 28-29 28.5 24-34 30.2 a November, 1961 infralabials 10-+ 11 in 2.1 per cent, 11 + 11 in 42.6 per cent, 11 + 12 in 29.8 per cent, 12 + 12 in 12.8 per cent, 12 + 13 in 8.5 per cent, 13+ 13 in 4.2 per cent; preoculars 1 +1 in 98 per cent, 2+ 2 in 2 per cent; postoculars 2 + 2 in 96 per cent, 2+ 3 in 2 per cent, 3+ 3 in 2 per cent. Habits——The black rat snake, or pilot black snake, is an excellent climber. One specimen was found in a tree 40 feet above the ground; another was found on a con- crete bridge support more than 20 feet off the ground. How the snake scaled the con- crete bridge support is a mystery. In the fall black rat snakes congregate in the vicin- ity of rock outcrops, where they may hiber- nate with rattlesnakes and copperheads. Fig. 196.—Distribution of Elaphe obsoleta. Vertical hatching indicates the presumed range of the subspecies obsoleta in Illinois; horizontal hatching, the presumed range of the subspecies spiloides; crosshatching, the area of intergra- dation between the two subspecies; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 205 In nature this snake is slow and deliber- ate. A disturbed individual often “freezes” in the position in which it is encountered, the kinks in its body producing the effect of a crooked stick. If annoyed, this snake raises its head, vibrates the tip of its tail rapidly, and lunges at the tormentor. A captive usu- ally becomes tame and eats well. The spe- cies feeds primarily on birds and small mam- mals. Like other rat snakes, obsoleta is a powerful constrictor. On several occasions the large eggs of this species have been found in wood rot. In almost every instance the approximately one dozen eggs were found in August or early September and contained snakes just ready to hatch. Illinois Distribution——The pilot black snake occurs over most of Illinois, fig. 196; it is sporadic in occurrence in predominantly prairie areas. It is common throughout the southern half of the state; it is not common in the Upper Mississippi River Border divi- sion. Apparently it is local and quite un- common in northeastern Illinois. Wooded bluffs seem to provide choice habitat. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Cook County: Dalton, Worth (Schmidt & Necker 1935); Knox County: Galesburg (H. Garman 1892); McLean County: (H. Garman 1892); St. Cra County: near St. Louis (Hurter 1893); Stark County: Elmira (Yarrow 1882a). Elaphe obsoleta spiloides Duméril, Bibron, & Duméril Gray Rat Snake Elathis spiloides Duméril, Bibron, & Dumeéril 1854:219 (type locality: New Orleans, Lou- isiana). Coluber spiloides, Wright & Wright 1952:585. Coluber obsoletus confinis, Cope 1877:64 (part). Elaphe obsoleta confinis, Cagle 1941:17. Elaphe obsoleta obsoleta % confinis, Neill 1949a:8. Elaphis obsoletus obsoletus nec Say, (H. Gar- man 1892:290 (part). Elaphe obsoleta, Breckenridge 1944:120 (part). Coluber lindheimerii, Davis & Rice 1883a:29 (part). Coluber lindheimert, Davis & Rice 1883):36 (part). Elaphis obsoletus lindheimeri, S. Garman 1884:27. 206 Ittinors NaturaAL History SurvEY BULLETIN Vol. 28, Art. I Fig. 197—An adult Elaphe obsoleta spiloides from Pope County, Illinois. The groundcolor is gray; the blotches are black or dark brown. Diagnosis.—A subspecies of Elaphe ob- soleta (largest Illinois specimen 1,690 mm. in total length), fig. 197, differing from E. o. obsoleta in the retention of a distinctly blotched pattern throughout life. The 26 to 32 dark dorsal blotches and alternating lateral spots on a gray groundcolor can be counted readily on the largest adults. Variation.—Sexual dimorphism and on- togenetic variation are evidently the same for E. o. obsoleta and spiloides except that spiloides adults do not differ so strikingly from juveniles. Only 1 of 12 adult and subadult specimens of spiloides at hand is so dark that the body blotches cannot be readily counted. ‘The counts of body blotches on the remaining 11 specimens range from 26 to 31 (average 29.4). For the 12 specimens, the tail length ranges from 14.7 to 18.4 (average 16.4) per cent of total length. Scutellation data are almost identical with those of Illinois speci- mens of E. o. obsoleta except for the slightly higher frequency of specimens with 27 scale rows on the anterior half of body. Ten speci- mens display the following variation: an- terior scale rows 24 in 16.7 per cent, 25 in 33.3 per cent, 27 in 50.0 per cent; scale rows at mid-body 25 in 33.3 per cent, 27 in 66.7 per cent; posterior scale rows 17 in 50 per cent, 19 in 50 per cent; ventrals in males 227 to 238 (average 231.1), in females 230 to 235 (average 233.1) ; caudals in males 78 to 86 (average 82.0), in females 73 to 79 (average 76); supralabials 8+ 8 in all; infralabials 11 + 11 in 42 per cent, 11 +12 in 29 per cent, 13+ 13 in 29 per cent; preoculars 1 + 1 in all. Habits.—The gray rat snake, more often called chicken snake in Illinois, is similar in behavior, feeding habits, and reproduc- tive habits to E. o. obsoleta. Individuals often enter buildings in search of rodents. Illinois Distribution.—Individuals iden- tical with Gulf Coast spiloides in pattern occur rather consistently in extreme south- eastern Illinois, fig. 196. The habitat of spiloides is similar to that of obsoleta. Speci- mens referable to obsoleta X spiloides inter- grades have been taken in Alexander, Ham- ilton, Jackson, Lawrence, Union, and Wabash counties. Although undocumented by specimens, a published record for the following locality November, 1961 is believed valid and is indicated on the distribution map by a_ hollow’ symbol: Wuite County: (Minton & Minton 1948). Elaphe vulpina vulpina (Baird & Girard) Western Fox Snake Scotophis vulpinus Baird & Girard 1853:75 (type locality: Racine, Wisconsin). Coluber vulpinus, Yarrow 1882a:101. Elaphe guttatus vulpinus, H. Garman 1892: 292-3. Elaphe vulpinus, Hurter 1911:178. Elaphe vulpina, Stejneger & Barbour 1917:84. Elaphe vulpina vulpina, Conant 1940:10-1. 2Coluber spiloides nec Duméril, Bibron, & Dumeéril, McLain 1899:3. Diagnosis.—A large, moderately stout- bodied snake (largest Illinois specimen 1,297 mm. in total length), fig. 198, usually with 25-25-21 rows of feebly keeled scales; ven- trals 192 to 210; caudals 53 to 69; supra- labials usually 8+ 8; infralabials usually Sm1TH: AMPHIBIANS AND REPTILES OF ILLINOIS 207 11+11; preoculars usually 1+ 1; post- oculars usually 2+ 2; anal plate divided; head wider than neck; adult pattern con- sisting of 34 to 42 red-brown dorsal spots on a yellow-gray groundcolor; an alternat- ing row of brown lateral spots on each side of body; head coppery colored; venter yel- low, boldly marked with black; juvenile similar except that yellow is lacking in groundcolor and blotches are dark chestnut or black. Variation.—In the western fox snake the tail of the male is proportionately larger than that of the female. Other differences are the number of caudals (58 to 69, aver- age 64, in males; 53 to 58, average 54.7, in females); number of tail rings (12 to 16, average 14, in males; 10 to 13, average 11.6, in females); and proportionate tail length (13.6 to 17.8, average 16.0, per cent of total length in males; 11.1 to 14.8, aver- age 13.0, per cent of total length in females). ; Fig. 198.—An adult Elaphe vulpina vulpina from Ford County, Illinois. The groundcolor 1s tan or yellow-brown; the blotches are chestnut brown. 208 Ittinoris Natura History Survey BULLETIN Vol. 28, Art. 1 Table 60.—Geographic variation in number of body blotches of Illinois Elaphe vulpina vulpina. Figures in parentheses are numbers of specimens. | NorrHEASTERN NorTHWESTERN I_tinors (13) West-CENTRAL Itirnots (4) East-CEentTRAL ILitrNors (33) Mean Iuitnots (9) CHARACTERISTIC : eee Range Mean Range Body blotches...... 37-52 41.4 35-41 The average number of ventrals and body blotches is slightly greater in females than in males. The juveniles are gray or white, prom- inently blotched with black or dark chestnut. Older individuals acquire a yellowish cast, and the blotches fade to a rich brown, which is often edged with black. The head becomes copper colored, and the head mottling tends to dim with age. The only geographic variation discerned in this snake is a north-to-south trend to- ward a reduction in the number of body blotches. This is illustrated in table 60. Individual variation in 40 specimens is not pronounced. ‘Their scutellation data are as follows: 25 anterior scale rows in 97 per cent, 25 in 3 per cent; scale rows at mid- body 25 in 79.1 per cent, 27 in 10.5 per cent, 23 in 5.2 per cent, 24 in 2.6 per cent, 26 in 2.5 per cent; scale rows posteriorly 21 in 78.5 per cent, 19 in 11.0 per cent, 20 in 8.0 per cent, 23 in 2.5 per cent. Supralabials are 8 +8 in 83 per cent, 8+ 9 in 11 per cent, 7+ 8 in 6 per cent; infralabials 11+ 11 in 61 per cent, 10+ 11 in 12 per cent, 11+ 12 in 9 per cent, 12+ 12 in 12 per cent, 9+9 in 6 per cent. Preoculars are 1+ 1 and postoculars 2 + 2 in 92 per cent, asymmetrical in 8 per cent. On most specimens some dorsal blotches are as narrow as 21% scale lengths and other blotches, particularly anteriorly, are 5 scale lengths in width. The average width is ap- proximately 4 scale lengths. Habits.—The western fox snake is prob- ably the most terrestrial member of the rat snake genus. Occasionally an individual can be found under the bark of standing dead trees or stumps 5 or 6 feet above the ground. The fox snake is abundant in the heavily farmed, black-soil prairies of central IIli- nois, and it apparently requires little vege- cover remains. It can be found from early spring until late fall (one active specimen was collected December 4) ; there seems to be a burst of activity in early June in the Urbana region. During these few weeks many more snakes are seen dead on the roads than during the rest of the season. An an- gered fox snake vibrates the tip of its tail and strikes at intruders. In captivity it us- ually becomes tame, but frequently it re- fuses to eat. Sixteen individuals were once found in March in an old well, where they had survived the winter. Judged from ma- terial regurgitated by captives, the food con- sists largely of small mammals and birds. Clutches of 8, 10, and 27 eggs of this snake have been found in soil and under objects on the ground. The egg shells ad- here to each other, and the eggs are difficult to pull apart. Hatching occurs in late Aug- ust and early September. Illinois Distribution——The western fox snake is common throughout the northern half of Illinois except in predominantly for- ested regions, fig. 199. This species appar- ently does well on the heavily cultivated — muck prairies of north-central Illinois, from which many other snakes have been almost or entirely exterminated. A The record of a single adult (INHS~ 1317) from Jerseyville, Jersey County, would be open to question except that the field tag is still attached to the specimen. — It is typical in all respects except for a rather — longer head. Jersey County includes some — prairie, but the countryside does not appear — to be typical vulpina habitat. - Although undocumented by specimens, a published records for the following local are believed valid; most are indicated on the — distribution map by hollow symbols: Bu- REAU County: Milo (Conant 1940); Cook County: Argo (Schmidt & Necker — 1935); Bloom Township (Necker 1939¢) 5 Chicago Ridge (Conant 1940); Evanston, — tation cover, as it is often found along fence- rows and in pastures where little natural November, 1961 Fig. 199.—Distribution of Elaphe vulpina. Hatching indicates the presumed range of the subspecies wulpina in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Hazelcrest (Schmidt & Necker 1935); Homewood (Conant 1940) ; Lemont (Neck- er 1939-); Du Pace County: Du Page Township (Necker 1939c); Naperville (Schmidt & Necker 1935) ; GkuNpy Coun- TY: Pequot (Necker 1939c); KANKAKEE County: Aroma Township’ (Necker 1939c); Lake County: Barrington (Necker 1939c) ; Beach (Schmidt & Necker 1935); Sayer Bog, Volo (Necker 1939c) ; La SALLE County: 4 mi. E La Salle, 3 mi. E Marseilles (Burt & Hoyle 1934); Mc- Henry County: McHenry (Schmidt & Necker 1935); McLean County: Bloom- ington (McLain 1899) ; Normal (H. Gar- man 1892); OcLte County: Polo, White Pines State Park (Conant 1940); Prorta County: Peoria (H. Garman 1892) ; Rock IsLanD County: Rock Island (Yarrow SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 209 1882a) ; Witt County: 4 mi. N Beecher (Burt & Hoyle 1934); Custer Park, Joliet (Schmidt & Necker 1935); Romeoville (Conant 1940); Wheatland Township (Schmidt & Necker 1935). Pituophis Holbrook This strictly North American genus in- cludes, in the United States, one species with 10 subspecies, or two species, each with sev- eral subspecies, the number of species and subspecies contingent upon the viewpoint of the specialist. One subspecies occurs in Illinois. Pituophis melanoleucus sayi (Schlegel) Bullsnake Coluber sayi Schlegel 1837:157 (type locality: Missouri; revised to vicinity of St. Louis, Missouri, by Schmidt 1953). Pityophis sayi sayi, Cope 1875:39. Pityophis catenifer sayi, S. Garman 1883:151. Pityophis sayi, Hay 1887a:10. Pituophis sayi, Jordan 1888:196. Pituophis sayi sayi, Necker 1933:8. Pituophis catenifer sayi, Edgren & Stille 1948:5. Pityophis catenifera sayi X bellona, H. Gar- man 1892:286-9. Pituophis malansleucus, Brendel 1857:254. Pityophis catenifer catenifer nec Blainville, H. Garman 1892:286-9. Diagnosis.—A large, moderately stout- bodied snake (largest Illinois specimen 1,880 mm. in total length), fig. 200, with 26 to 31 rows of scales on the anterior part of the body, 29 to 33 rows at mid-body, and 21 to 25 rows on the posterior part of the body; scales feebly keeled; head wider than neck; rostral plate enlarged and projecting for- ward; supralabials 8 or 9 on each side, usu- ally with sutures heavily margined with black; infralabials 11 to 13 on each side; preoculars usually 1+ 1 and _ postoculars 3+3 or 4+ 4; prefrontal plates 4; ven- trals 213 to 233; caudals 48 to 61; anal plate entire; groundcolor yellow, with 36 to 54 conspicuous dorsal body blotches that alter- nate with two rows of lateral spots on each side; anterior and posterior body blotches black, mid-body blotches brown; tail with 8 to 15 black rings; venter yellow, checkered with black. Variation.—The male bullsnake differs from the female in the greater number of caudals, smaller number of ventrals, and 210 relatively greater tail length. Ten males have 213 to 230 ventrals (average 221.9) and 54 to 61 caudals (average 58.2); tail length ranges from 10.5 to 14.0 (average 12.6) per cent of total length. Ten females have 222 to 233 ventrals (average 227) and 48 to 57 caudals (average 52.1); tail length ranges from 10.1 to 13.0 (average 11.4) per cent of total length. The juveniles differ from the adults in duller coloration and possession of almost unicolorous body blotches. The groundcolor is usually dull tan, rather than yellow, and the blotches at mid-body are usually black, rather than brown. The average number of dorsal blotches in Ittrinors NarurAL History Survey BULLETIN Vol. 28, Art. 1 this snake is greater in specimens from northern localities than from elsewhere in the state. Twenty-three central Illinois specimens range from 36 to 54 (average 48.5) in blotch counts and from 8 to 15 (av- erage 11.3) in tail rings; eight northwest- ern Illinois specimens range from 46 to 54 (average 50.1) in blotch counts and from 11 to 14 (average 11.5) in tail rings. Other variation, which is neither sexual nor geographic, is as follows: anterior scale rows 26 to 31 (average 28); scale rows at mid-body 29 to 33 (average 31.1); posterior scale rows 21 to 25 (average 23.4); upper labials 8 + 8 in 20 per cent of specimens at hand, 8+ 9 in 40 per cent, 9+9 in 35 per Fig. 200.—An adult Pituophis melanoleucus sayi from Mason County, Illinois. The ground- color is bright yellow or tan; the blotches are black anteriorly and posteriorly but rich brown at mid-body. November, 1961 cent, and 6+ 8 in 5 per cent; infralabials 12 + 12 in 40 per cent, 11+ 12 in 10 per cent, 12 + 13 in 15 per cent, 13 + 13 in 25 per cent, 11 + 13 in 5 per cent, and 13 + 14 in 5 per cent; azygous scales absent in 39 per cent, 1 azygous scale in 50 per cent, 2 scales in 11 per cent. Most Illinois speci- mens are prominently blotched; a few indi- viduals appear faded. Habits.—The large bullsnake, although essentially a terrestrial reptile, climbs and burrows readily in search of food. When first encountered, a bullsnake vibrates its tail and hisses loudly, with its mouth par- tially opened. It is rather vicious, but cap- tives usually become tame and feed well. The food of the bullsnake consists of mam- mals, birds, and bird eggs. It is a powerful constrictor and is of considerable economic importance because of its predation on in- jurious rodents. The species is oviparous. Reproductive habits are probably similar to those of the rat snakes in the genus Elaphe. Illinois Distribution—The distribution pattern, fig. 201, of the bullsnake is one of the most puzzling of those of Illinois rep- tiles. The species occurs commonly in the extensive sand prairies of central and north- ern Illinois and less commonly in the black- soil prairies east of the sand areas to at least De Witt County. Although bullsnakes are occasionally found in small wooded areas, they apparently do not occur in extensively forested regions. The paucity of records just west of the Illinois River is not readily explained; the available evidence suggests that bullsnakes are uncommon there. In northeastern Illinois, bullsnakes are closely restricted to the Kankakee sand area. A bullsnake (FAS 19) reportedly found near Urbana, Champaign County, and a pub- lished record for Champaign (Stull 1940) have not been plotted on the map, fig. 201, since there is some possibility that the speci- mens m‘ght have been collected elsewhere. It hardly seems possible that this large, spec- tacular species could occur in a region so well studied and still be known from only two examples. The published record by Gaige (1914) for Richland County has been dismissed as probably being based on mis- identification, inasmuch as she reported the bullsnake as common there but failed to mention the abundant prairie kingsnake. Richland County does not appear to contain SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 211 suitable Pituophis habitat. However, a small relict colony of Pituophis is known in the sandy soil of Knox County, Indiana, a few miles to the east of Richland County. Old published records for Pituophis in Madison and St. Clair counties are believed to be Fig. 201.—Distribution of Pituophis melano- leucus. Hatching indicates the presumed range of the subspecies sayz in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, published records believed to be valid. The lower map depicts the total range of the bull- snake complex of subspecies in the United States. It does not include the pine snakes. valid, the absence of museum specimens not- withstanding. Sometimes bullsnakes are found under objects on the ground, but the majority of the bullsnakes taken as specimens are discov- ered while they are crossing roads or they are encountered in cultivated fields or sand prairies. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Grun- py County: vicinity of Dwight (Stille & Edgren 1948); KANKAKEE County: Pem- broke Township (Schmidt & Necker 1935) ; Mapison County: (Stull 1940) ; Sr. CLarr County: opposite St. Louis (Hurter 1903) ; Witt County: Custer Park (Stille & Ed- gren 1948). Lampropeltis Fitzinger This New World genus is represented in the United States by seven species, some of which have several well-marked subspecies: Five species and subspecies are known in Illinois. Many of the subspecies are sufficient- ly distinctive in general appearance to suggest different species of snakes, but they are known to have geographically complemen- tary ranges and to interbreed where their ranges meet. Ittrinois NaTuRAL History SurvEY BULLETIN Vol. 28, Art. 1 Lampropeltis calligaster calligaster (Harlan) Prairie Kingsnake Coluber calligaster Harlan 1827:359 (type lo- cality: Missouri; revised to vicinity of St. Louis, Missouri, by Schmidt 1953). Ophibolus calligaster, Cope 1875:37. Lampropeltis calligaster, Jordan 1888:197. Lampropeltis calligaster calligaster, P. W. Smith 1947:34. Ophibolus evansii Kennicott 1859:99 (type lo- cality: prairies of central Illinois). Coluber emoryi nec Baird & Girard, Cope 1875:39 Ophibolus rhombomaculatus nec Holbrook, Da- vis & Rice 1883a:29. Lampropeltis rhombomaculatus nec Holbrook, Jordan 1888:197. ?Pituophis catenifer sayi nec Schlegel, Gaige 1914:4. setae SE Fig. 202.—An adult Lampropeltis calligaster calligaster from Sangamon County, Illinois. The groundcolor is gray, tan, brown, or light olive; the frequently indistinct blotches are dark gray or brown. Some individuals appear almost unicolorous; others, especially those in south- eastern Illinois, have distinct red-brown blotches. aati November, 1961 SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS Diagnosis.—A large, moderately slender snake (largest Illinois specimen 1,327 in total length), fig. 202, usually with 25 scale rows on the anterior half of the and 19 or 21 posterior rows; scales sm head little wider than neck; eyes s 213 supralabials 7+ 7 or 8+ 8; infralabials 9 mm. to 11 on each side; preoculars 1 + 1; post- oculars 2 + 2; ventrals 194 to 213; caudals body 41 to 57; anal plate entire; groundcolor ooth; gray, brown, or straw-color with 41 to 64 mall; dark dorsal body blotches and two or three Table 61.—Sexual dimorphism in Illinois Lampropeltis calligaster calligaster. Figures in parentheses are numbers of specimens. Mates (24) FemMAt-es (13) Range Mean CHARACTERISTIC Mae re NR dN te Oe NT ge ber ahs oe e's we 3 ate ERE Ss eee ee SEA! Ge SEE GAGS ne a ee eR a Tail length as percentage of total length................... Ms eet Werle es is eh crde ih nds swore vids ee De wind Range Mean 194-210 | 203.2 44-57 50.0 1V3=14. 7) 13.3 10-21 eel 195-213 | 206.3 41-48 44.8 11.9-14.4| 12.8 9-14 12.1 Table 62.—Blotch count of male and female specimens of Illinois Lampropeltis calligaster calligaster. Figures in parentheses are numbers of specimens. SouTHERN ILLINOIS East-CentTRAL ILLINors West-CEenTRAL ILLINOIS CHARACTER- ISTIC Males (6) | Females (4) Range |Mean| Range ‘Mean —= Blotch count | 41-51 | 45.1} 42-49 | 45.0 Males (17) | Females (14) Males (9: Females (4) Range 43-57 | 49.1 | Mean! Range 40-51 Mean) Range |Mean} Range |Mean 45.9} 44-64 | | | 49.3! 43-46 | 44.7 Table 63.—Geographic variation in Illinois Lampropeltis calligaster in parentheses are numbers of specimens. calligaster. Figures SOUTHERN | West-CENTRAL East-CENTRAL ILLiNots ILLINOIS ILLrNotIs (9 MALEs, (6 Mates, (6 Mates, CHARACTERISTIC 5 FEMALES) 5 FeMALEs) 5 FEMALES) Range Mean Range Mean Range Mean Ventrals SLES, ces veel Ae Ne me a a emt 200-210 | 205.3 197-207 | 203.0 194-207 | 200.5 EGE: [CRT en ae ae eer peetO=213) 20S 199-209 | 205.5 195-209 | 202.0 Caudals 1 LESS Sea trails 0 RI SG ae a ara 44-53 49.6 47-57 Sal 46-51 48.2 gga] et EES eee eae an aa 45-47 46.0 42-47 45.0 41-48 43.5 Tail length as percentage of total length | | ELE SE ee Oe Re a Ue 12.0-13.8} 12.8 12.8-14.7| 1358) HS =13e4) | IOS L0G L SS ee pe ek el (PeOaI Stag AO awe a ase SEO Eisai 25) MEE GECHES,. 6 < sks een a tka. ot | 41-51 45.0 43-64 47.6 43-57 | 48.9 214 series of dark spots on each side, alternating with the dorsal blotches; dorsal blotches ex- tending ventrad to scale row 5, 6, or 7; venter gray-white or yellowish gray, with irregular and usually dim dark markings. Variation.—In the prairie kingsnake, sex- ual dimorphism in scutellation is slight, but it can be detected by comparing averages, table 61. In central Illinois specimens, there is a tendency toward a higher blotch count in males than in females; in southern Illinois specimens, blotch count means are identical in the two sexes. This characteristic is sum- marized in table 62. The juvenile differs from the adult chiefly in color and prominence of pattern. The baby kingsnake has distinct reddish blotches, with black borders above; the venter is dis- tinctly marked with black. In pattern the young calligaster closely resembles the young of the related milk snake, Lampropeltis tri- angulum, but it can be distinguished by the narrower blotches, which extend ventrad only to the fifth or sixth scale row (fourth or lower in the milk snake). Except for the tendency toward greater sexual dimorphism in the northern part of the range, no geographic variation is obvious for the prairie kingsnake in Illinois. Varia- tion data for three samples are summarized in table 63. The number of scale rows anteriorly is distributed as follows: 23 in 7.5 per cent of specimens, 24 in 7.5 per cent, 25 in 77.5 per cent, 26 in 7.5 per cent; at mid-body, 23 in 2.5 per cent, 25 in 90.0 per cent, 26 in 5.0 per cent, 27 in 2.5 per cent; posteriorly, 19 in 39.5 per cent, 20 in 7.5 per cent, 21 in 53.0 per cent. Supralabials are 6+ 7 in 2.8 per cent of the specimens, 7 + 7 in 50.2 per cent, 7 +8 in 30.4 per cent, 8+8 in 11.0 per cent, 7 +9 in 2.8 per cent, and 8 + 9 in 2.8 per cent. Infralabials are 9+ 9 in 31.0 per cent of the specimens, 9 + 10 in 33.0 per cent, 9 + 11 in 2.8 per cent, 10 + 10 in 22.0 per cent, 10+ 11 in 5.5 per cent, 11+ 11 in 2.8 per cent, and 12+ 13 in 2.8 per cent. Preoculars are 1 +1 in 94 per cent of the specimens, 1 + 2 in 3 per cent, 2+ 2 in 3 per cent; postoculars are 2+2 in 91 per cent, 2 + 3 in 6 per cent, and 3 + 3 in 3 per cent. Occasional adult specimens retain a well- pronounced pattern of reddish blotches with black margins. A few individuals are al- Ittrinors NaturRAL History SurvEY BULLETIN omit att Vol. 28, Art. I ; most unicolorous, only traces of the blotches being evident; in some of these are dim, — longitudinal light bands in the form of a pair of paravertebral bands and a lateral stripe. The majority of adults and subadults are distinctly blotched, but the pattern is not in great contrast to the groundcolor. A specimen (from Springfield) in the Chi- cago Academy of Sciences is aberrant in pattern in that a pair of dorsolateral dark stripes extend almost the length of the body, replacing the usual blotched pattern. The — spots on the tail have not fused to form stripes. Another aberrant specimen (INHS 6189) collected December 2, 1951, 3 miles south of Philo, Champaign County, suggests a triangulum X calligaster hybrid. This snake, a female, 575 mm. in total length, has 24-25-19 scale rows, 203 ventrals, 51 cau- dals, 7 +8 supralabials, 10+ 10 infrala- bials, 1 +2 oculars, and 42 dorsal body blotches. The chin and venter are promi- — nently checkered with black and white, and — the dorsal blotches extend ventrad onto the fourth and fifth scale rows anteriorly. Ex- cept for the presence of a prominent sub- orbital dark spot, the head pattern is typical of calligaster. Habits.—The prairie kingsnake shows a preference for old fields. In bluegrass plots — the species is easily confused with the racer, — as it sometimes moves so fast that the — blotched pattern is not evident. Captured in- dividuals vibrate the tail tip and usually try — to bite. Most captives become tame, but they usually do not feed well in cages. This — kingsnake occasionally hibernates in road embankments. On mild days some individ- — uals may be enticed from their hibernating — chambers by the winter sun. They have — been found active in November, December, ; and February, and they are among the first — snakes to be seen in early March. Captives — have disgorged small mammals, and one specimen regurgitated an equally large prai- — rie kingsnake. Klimstra (1959a) noted that, — in southern Illinois, small mammals make up — 68.6 per cent of the diet and that amphib- — ians, reptiles, birds, and insects constitute the remaining percentage. % A captive specimen from central Illinois — laid 9 eggs on July 5. Cagle (1942a) ren ported a clutch of 9 eggs for a southern IIli- nois specimen. Young of the year are in evi- — dence in September. gi —————— November, 1961 Illinois Distribution.—The prairie king- snake, abundant in prairie regions in the southern two-thirds of Illinois, is a charac- teristic species of the Outlier Prairies of the Southern Division, fig. 203. The species ex- Fig. 203.—Distribution of Lampropeltis cal- ligaster. Hatching indicates the presumed range of the subspecies calligaster in Illinois; solid circles indicate localities represented by specimens examined during this study; open circles, published records believed to be valid. The lower map depicts the total range of the species in the United States. tends northward on the central prairies to Tazewell and McLean counties, but it is much less common on the heavily farmed black-soil prairies and apparently is re- stricted to small areas of poorer soil that support a brushy cover. L. calligaster has not been found in the vicinity of Urbana. The prairie kingsnake and the ecologically similar fox snake overlap in distribution, but they may not compete inasmuch as the fox snake seems to thrive in heavily cultivated black soils. Although L. calligaster occurs in the ex- treme southern tip of.the state, it is evidently SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 215 uncommon in the predominantly forested re- gions there. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAcK- soN County: Murphysboro (Ditmars 1945) ; Maptson County: Highland (Hur- ter 1893); Morcan County: Meredosia (Weed 1923); WapasH County: Mount Carmel (Schneck 1880a). Lampropeltis getulus (Linnaeus) Nine subspecies of this transcontinental species occur in the United States. “wo in- habit Illinois, intergrading in the southern third of the state. Lampropeltis getulus holbrooki Stejneger Speckled Kingsnake Lampropeltis holbrooki Stejneger 1902:150 (type locality: valley of the Mississippi) ; Stejneger & Barbour 1917:88. Lampropeltis getulus holbrooki, Hurter 1911: 185. Ophibolus getulus sayi, Cope 1875:37. Lampropeltis getulus sayi, Jordan 1888:196. Diagnosis.—A large, moderately slender snake (largest Illinois specimen 1,232 mm. in total length), fig. 204, usually with 21 an- terior and 17 or 19 posterior rows of smooth scales; anal plate entire; head little wider than neck; supralabials usually 7+ 7; in- fralabials usually 9 +9; preoculars 1+ 1, postoculars, 2 + 2; 2, 3, or 4 temporals on each side; ventrals 201 to 219; caudals 41 to 56; groundcolor above black, each scale containing a yellow spot, sometimes dots fused to form traces of crossbands; venter checkered with black and yellow, the black usually predominating; labial sutures heay- ily margined with black. Variation.—Since the two Illinois sub- species of Lampropeltis getulus are identical in scutellation and proportions, variation for both races as well as intergrades is included here. Twelve males have 42 to 56 (average 49.5) caudals; tail length ranges from 11.2 to 14.6 (average 12.9) per cent of total length. Twelve females have 41 to 49 (av- erage 45.2) caudals; tail length ranges from 10.7 to 14.5 (average 12.1) per cent of total length. ILtinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 1 Fig. 204.—An adult Lampropeltis getulus holbrooki from Randolph County, Illinois. The groundcolor is blue-black; each scale contains a round yellow or yellowish white spot. Juveniles of L. g. holbrooki differ from adults in that some of their middorsal scales lack light dots. Prominent light crossbands as well as light spots are present in juveniles but sometimes difficult to count because of their irregularity. Three juveniles have 69, 78, and 82 crossbands on the body. Adults are too speckled for reliable counts to be made. Twelve specimens of Illinois L. g. niger, both juveniles and adults, have 40 to 56 crossbands. Otherwise, juveniles of hol- brooki are indistinguishable from those of niger; the possible difference in number of crossbands needs checking with additional specimens. Individual variation in a sample of 25 specimens of L. getulus is as follows: an- terior scale rows 19 in 16 per cent, 20 in 24 per cent, 21 in 60 per cent of specimens; scale rows at mid-body 21 in 88 per cent, 22 in 4 per cent, 23 in 8 per cent; posterior scale rows 17 in 17 per cent, 18 in 4 per cent, 19 in 71 per cent, 20 in 8 per cent; ventrals 201 to 218 (average 211.7) ; supra- labials 7 + 7 in 96 per cent, 8 + 7 in 4 per cent; infralabials 7+ 8 in 4 per cent, 8+ 8 in 4 per cent, 8 + 9 in 8 per cent, 9+ 9 in 76 per cent, and 9+ 10 in 8 per cent. Habits.—This powerful kingsnake is slow and deliberate in its movements. When first encountered, an individual vibrates its tail and strikes viciously. Captives usually be- come tame quickly, however, and they are popular as pets. The species is most often encountered under flat rocks or logs or found crossing roads. Captive individuals feed on other snakes, birds, and mammals, all of which are constricted by the muscular body of the kingsnake before being swal- lowed. A large captive female deposited 13 large, smooth eggs on July 19 and 20. These eggs, strongly adherent, averaged 21 X 37 mm. By October 12 they had increased in size to an average of 39 X 26 mm. but had not hatched. Each egg contained a well-formed but dead snake. Cagle (1942a) recorded that a clutch of 9 eggs was laid in mid-June and was hatched in mid-August. Illinois Distribution.—The speckled kingsnake probably occurs sporadically throughout western I]linois south of Peoria, fig. 206. The requisite habitat of wooded, hilly terrain is so restricted in most of that part of the state that the rarity of holbrooki in collections is not surprising. Though the November, 1961 Illinois range of holbrooki is more extensive than that of the closely related niger, hol- brooki is apparently much less common. Most of the Illinois specimens have been taken in the Lower Mississippi Border di- vision. Intergradation of holbrooki and niger is exhibited by specimens from extreme south- western Illinois, and intergrades probably occur in most of the Southern Division. Single juveniles cannot be referred with cer- tainty to either race, since the subspecific difference is one of pattern only. In a series from southern Union County, the niger in- fluence predominates. In material from Jack- son and northern Union counties, the two pattern types are about equally distributed. In eastern Illinois, no intergrades have been taken. Specimens from Effingham County are typical holbrooki; those from adjacent Cum- berland and Jasper counties are typical niger. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAcK- son County: Elkville, Makanda (Cagle 1942a); Murphysboro (Ditmars 1945); Peoria County: Peoria (H. Garman 1892); St. Crain County: (Hurter 1911). SmitTH: AMPHIBIANS AND REPTILES OF ILLINOIS Al “I Lampropeltis getulus niger (Yarrow) Black Kingsnake Ophibolus getulus niger Yarrow 1882b:438 (type locality: Wheatland, Indiana); Yar- row 1882a:93. Lampropeltis getulus niger, Blanchard 1921: 18, 43-8. Lampropeltis getulus nigra, Pratt 1923:221. Ophibolus getulus sayi nec Holbrook, Yarrow 1882a:93 (part). Lampropeltis getulus holbrooki nec Stejneger, Myers 1926:291. Diagnosis.—A subspecies of Lampropeltis getulus (largest Illinois specimen 1,369 mm. in total length), fig. 205, differing from L. g. holbrooki only in detail of dorsal pattern: speckling reduced to 40 to 56 narrow cross- bands, each of which forks on the side; some of lateral scales with light centers, others black. Variation.—Sexual variation is identical in holbrooki and niger. Juveniles of niger differ from the adults only in having a some- what brighter pattern. Comparison of counts and measurements of three specimens from Cum- berland and Jasper counties and 15 from ex- treme southeastern Illinois reveals no trends in geographic variation. Individual variation in scutellation and proportions for means for Fig. 205.—An adult Lampropeltis getulus niger from Alexander County, Illinois. groundcolor is blue-black; small dots of yellowish white tend to form crossbars at regular intervals. The Fig. 206.—Distribution of Lampropeltis get- ulus. Vertical hatching indicates the presumed range of the subspecies Aolbrooki in Illinois; horizontal hatching, the presumed range of the subspecies niger; crosshatching, the area of intergradation between the two _ subspecies; solid circles indicate localities represented by specimens examined during this study; open circles, published records believed to be valid. The lower map depicts the total range of the species in the United States. the species is summarized under L. g. hol- brooki. Individuals vary in pattern from those that are almost uniformly black to those, usually juveniles, in which the cross- bands are almost a scale length in width. Habits.—The black kingsnake is similar to the speckled kingsnake in behavior and reproductive habits. A captive female depos- ited 13 eggs in early July. The 13 young hatched on August 30 and 31. Illinois Distribution.—The black king- snake occurs throughout eastern Illinois from Edgar County southward, fig. 206. The number seen dead on highways indicates that this snake is rather common in south- eastern Illinois. Although undocumented by _ specimens, published records for the following localities Ittinois NATURAL History SurvEY BULLETIN Vol. 28, Art. 1 are believed valid; most are indicated on the distribution map by hollow symbols: UNIon County: Dug Hill (H. Garman 1892); WasasH County: Mount Carmel (Yar- row 18826). Lampropeltis triangulum (Lacépéde) Ten subspecies of Lampropeltis triangu- lum are currently recognized. Two partic- ularly well-marked races occur in Illinois. They intergrade in a wide belt across the central part of the state; in this area their characters show a bewildering overlap. The trivial name doliata of Linnaeus is applied to the milk snakes by most recent authors, who believe that doliata, which has priority over triangulum, refers to a milk snake. The name triangulum is retained for the species by other authors who believe that the description of doliata better fits the scar- let snake of the genus Cemophora. Lampropeltis triangulum triangulum (Lacépéde) Eastern Milk Snake Coluber triangulum Lacépéde 1788:86 (type lo- cality: America; revised to vicinity of New York City, New York, by Schmidt 1953). Lampropeltis triangulum triangulum, Blanch- ard 1921:108, 205. Lampropeltis triangulum, Ditmars 1929:90. Lampropeltis doliata triangulum, Wright & Wright 1952:585. Lampropeltis triangulum triangulum X syspila, Langebartel 1947:27-8. Ophibolus doliatus triangulus, Yarrow 1882a: 91. Ophibolus triangulus triangulus, H. Garman 1892:295-6. Lam propeltis 1906:178. Osceola doliata triangula, Cope 1900:886. Ophibolus doliatus nec Linnaeus, H. Garman 1892:299. Lampropeltis doliatus nec Linnaeus, Hankin- son 1917:327. Ophibolus eximus, Kennicott 1855:592. doliatus triangulus, Surface Diagnosis.—A medium-sized, moderately slender snake (largest Illinois specimen 1,110 mm. in total length), fig. 207, usually with 21 anterior and 17 or 19 posterior rows of smooth scales; anal plate entire; head lit- tle wider than neck; supralabials usually 7 +7; infralabials usually 9 + 9; preoculars 1+ 1; postoculars 2+ 2; ventrals 198 to 215; caudals 36 to 52; groundcolor gray or white, with 33 to 46 black-margined, brown dorsal blotches alternating with 1 or 2 rows November, 1961 SmiTtTH: AMPHIBIANS AND REPTILES OF ILLINOIS Fig. 207A juvenile Lampropeltis triangulum triangulum from Lake County, Illinois. The groundcolor is light gray or tan; the blotches are red-brown or dark brown, heavily margined with black. of lateral spots on each side; dorsal blotches extending ventrad to scale row 2, 3, 4, or 5; venter prominently checkered with black and white; head pattern a dark chevron-shaped marking. Variation.—In Lampropeltis triangulum triangulum the average number of caudals is greater in males than in females and, sur- prisingly, males have a slightly higher blotch count on the body. The usual dimorphism in proportionate tail length and number of tail rings is not evident. Seven males and five females, exclusive of triangulum X syspila intergrades, have, respectively, 46 to 52 (av- erage 49.6) caudals and 35 to 46 (average 40.3) dorsal body blotches; 42 to 46 (aver- age 44.6) caudals and 33 to 43 (average 38.6) body blotches. Juveniles of triangulum are more brightly colored than adults; they possess black-mar- gined red, rather than brown, dorsal and lateral spots. There is some indication of a proportionately shorter tail in hatchlings. Geographic variation is summarized in table 64. Eastern milk snakes from the northernmost Illinois counties are pheno- typically triangulum. Yet in the sample from northwestern Illinois some slight influence of syspila is suggested by the number of tail rings, by the lateral rows of spots, and by the size of dorsal blotches. Intergradation of triangulum and syspila in western Illinois occurs at least as far south as Pike County, one specimen from near Pearl being approximately intermediate but closer to syspila. Specimens from Ham- ilton and Adams counties are unassignably intermediate. Intergradation in eastern [Ili- nois apparently occurs in a narrower zone. Material from Tazewell and De Witt counties is closer to triangulum; Champaign and Vermilion county specimens are almost 220 Ittrnoris NaturRAL History SurRvVEY BULLETIN Vol. 28, Art. 1 Table 64.—Geographic variation in Illinois Lampropeltis triangulum triangulum and L. t. triangulum X syspila intergrades. Figures in parentheses are numbers of specimens. NorTHEASTERN Ittinors (8) CHARACTERISTIC Range Mean Range Venttalst i en roce 202-215 | 209.3 Caundals2’en eer 45-52 48.5 42-46 Tail length as per- centage of total lengths oct S 5 12.9-15.1| 13.9 |11.7-12.6 Rows of lateral Spots. eens wes Dee NS yd 124-2 Scale row contact- ing dorsal blotch at mid-body...... 2-6 4.1 2-5 Body blotches...... 35-46 39.1 33-43 Parlisingss.. 5 etry 9-12 10.2 8-10 *Counts based on 10 rather than 4 specimens. exactly intermediate; a series from Coles County shows more syspila influence. Most intergrades from areas where the syspfila in- fluence predominates look like syspila be- cause of their red color, but they exhibit intergradation in details of pattern. Individual variation in the number of scale rows and in head squamation is apparently identical in L. t. triangulum and syspila. Ac- cordingly, these counts for 40 specimens of triangulum, syspila, and the intergrades are combined and are presented here. Anterior scale rows are 21 in 95.0 per cent, 22 in 2.5 per cent, 23 in 2.5 per cent of specimens; scale rows at mid-body are 21 in 95 per cent, 23 in 5 per cent; posterior scale rows are 17 in 51.0 per cent, 18 in 5.5 per cent, 19 in 41.0 per cent, and 21 in 2.5 per cent; supralabials are 7 + 7 in 97 per cent, 7 + 8 in 3 per cent; infralabials are 8 + 9 in 14.5 per cent, 9+9 in 82.5 per cent, and 9+ 10 in 3.0 per cent. An albino specimen (INHS 5409), a male bearing the label “Chicago Area,” is 929 mm. in total length. This male is typical in scu- tellation but it is cream colored and has dark red eyes. Anteriorly the venter has an ob- scure checkered pattern; posteriorly it is im- maculate. Traces of the dorsal pattern are discernible in the form of blotch margins. This specimen has approximately 35 body blotches and 10 tail rings. NorTHWESTERN Itinois (4) 201-209 | 204.0 East-CENTRAL ILuinots (9) West-CENTRAL Ittinots (4) Mean | Range 205-213 | 208.7 | 198-213 | 204.8 44.0 45-48 46.7 36-52 47.5 12.2 |12.5-13.1} 12.8 |12.4-15.1) 13.4 nitieteMoere 1 I SE 3.4 1-2 B34 0-4 2.0 39.0 21-33* | 26.9 25-38 29.8 8.7 6-9* ie 7-11 8.2 Habits.—The eastern milk snake is ap- parently common in the Chicago area but distinctly uncommon over the rest of IIli- nois. It is most often found by raising logs, rocks, or debris. The scanty information available on habits of the species in Il]linois is based largely on behavior of captives. Like other kingsnakes this rather small snake vibrates its tail when disturbed. The species is known to eat small mammals, liz- ards, and snakes. Pope (19444) recorded that 8 to 16 ad- herent eggs are laid in June and early July, but it is not certain that his observation was based on Illinois specimens. Illinois Distribution.—The eastern milk snake is a forest species, although in Illinois — it evidently is not strictly confined to wooded ~ regions. L. t. triangulum occurs in the north-— ern third of the state, extending south to about Iroquois and Whiteside counties, fig. 208. L. t. triangulum X syspila intergrades occur from these localities southward to Clark and Greene counties. Although undocumented by _ specimens, published records for the following localities” are believed valid; most are indicated on the distribution map by hollow symbols: Bu- REAU County: Milo (Cope 1900); Coox County: Beverly Hills, Chicago Ridge, Edgebrook (Schmidt & Necker 1935) ; Glen- November, 1961 . i | Fig. 208.— Distribution of Lampropeltis tri- | angulum. Vertical hatching indicates the pre- | sumed range of the subspecies triangulum in _Ulinois; horizontal hatching, the presumed _ tange of the subspecies syspila; crosshatching, the area of intergradation between the two subspecies; solid circles indicate localities rep- _ Tesented by specimens examined during this study; open circles, published records believed | to be valid. The lower map depicts the total range of the species in the United States. view (Necker 1939c); Kenilworth, North- brook, Richton Park, Willow Springs (Schmidt & Necker 1935); Du Pace County: Glen Ellyn, Hinsdale (Schmidt & Necker 1935) ; Naperville (Necker 1939c) ; | = County: Elburn (Necker 1939c) ; KANKAKEE County: Rock Creek Park Stille & Edgren 1948); Knox County: /Galesburg (H. Garman 1892); Laxke County: Deerfield, Grass Lake (Schmidt /& Necker 1935); Waukegan (Necker | Saal McHenry County: McHenry (Necker 1939c); McLean County: Nor- mal (H. Garman 1892); Menarp Coun- pTy: Athens (Blanchard 1921); Prorra County: Peoria (H. Garman 1892); | STARK County: Elmira (Yarrow 1882a) ; | | . SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 2 bo STEPHENSON County: Freeport (H. Gar- man 1892); VERMILION County: Danville (Blanchard 1921); Witt County: Joliet (Schmidt & Necker 1935); Romeoville (Necker 1939c). Lampropeltis triangulum syspila (Cope ) Red Milk Snake Ophibolus doliatus syspilus Cope 1£88:384 (type locality: Richland, Illinois; revised to Richland County, Illinois, by Blanchard 1921). Osceola doliata syspila, Cope 1900:892. Lampropeltis triangulum syspila, Blanchard 1921:179-87. Lampropeltis doliata syspila, Wright & Wright 1952:585. Ophibolus doliatus Yarrow 1882a:89. Ophibolus triangulum doliatus nec Linnaeus, H. Garman 1892:295-6. Lampropeltis doliatus nec Linnaeus, Hurter 1911:184. Ophibolus doliatis nec Linnaeus, Hurter 1893: 255%. Osceola doliata doliata nec Linnaeus, Cope 1900:890. Osceola doliata collaris, Cope 1893a:1069. Osceola doliata clerica, Cope 1900:888. Ophibolus doliatus clericus, Brown 1901:73. Osceola elapsoidea nec Holbrook, Davis & Rice 18834a:29. Ophibolus elapsoideus nec Holbrook, H. Gar- man 1892:299-300. Lampropeltis elapsoides elapsoides nec Hol- brook, Wright & Wright 1952:586. Ophibolus doliatus coccineus nec Schlegel, Da- vis & Rice 1883a:29. Lampropeltis doliatus coccineus nec Schlegel, Jordan 1888:197. Diagnosis.—A subspecies (largest IIli- nois specimen 844 mm. in total length) of Lampropeltis triangulum, fig. 209, differing from L. ¢. triangulum in color and pattern: 19 to 26 crimson, black-edged dorsal blotches between head and anus; dorsal blotches ex- tending ventrad on the sides to ventrals or at least to first or second scale rows; one or less than one complete row of lateral spots alternating with dorsal saddles; tail with 4 to 8 black-margined red rings; head pattern without a chevron-shaped mark, with a pair of supraocular light spots. Variation.—Sexual variation in L. t. sys- pila parallels that in L. ¢. triangulum. Eight males have 45 to 50 (average 47.0) caudals and 19 to 26 (average 23.1) body blotches; six females have 42 to 49 (average 44.2) caudals and 21 to 26 (average 22.5) body blotches. Juveniles and adults are alike in pattern. doliatus mec Linnaeus, 272 ——— Itttnots Natura History SurRvEY BULLETIN Vol. 28, Art. I Fig. 209.—An adult Lampropeltis triangulum syspila from Union County, Illinois. The groundcolor is light gray or white; the blotches are bright red, heavily margined with black. No geographic variation within Illinois has been discerned for syspila except for in- tergradation with triangulum, which has been described under that subspecies. Individual variation in a sample of 14 specimens of syspila is as follows: ventrals 197 to 213 (average 202.5), tail length 11.9 to 14.1 (average 13.0) per cent of total length. Variation in scale rows and head squamation has been summarized under L. t. triangulum. The dorsal blotches in 14 specimens at hand extend to the edges of the ventrals or onto the first or second scale row. Forty-three per cent of the specimens possess a complete row of lateral spots al- ternating with the dorsal saddles; the others possess an incomplete row. An extreme case of the latter pattern is found in a Jasper County specimen in which the lateral spots are on only the posterior third of the body. Habits.—This brightly colored snake is similar in habits to the eastern milk snake. There is some evidence that it is at least par- tially nocturnal. Individuals have been found in rotten logs or under bark of stumps. Feeding and reproductive habits are pre- sumably similar to those of the eastern milk snake. Illinois Distribution—The red milk snake, one of the most colorful of the Illi- nois reptiles, occurs:in wooded regions of southern Illinois north to the Shelbyville Moraine in the eastern part of the state and to Calhoun County in the western, fig. 208. More individuals have been collected under flat rocks on wooded or grassy hillsides of the Lower Mississippi Border division than - elsewhere in the state, but even there syspila - is quite uncommon. bs Although undocumented by specimens, » published records for the following localities are believed valid and are indicated on the » distribution map by hollow symbols: CAL-— HOUN County: Hardin (Blanchard 1921); | Jackson County: Murphysboro (Ditmars » 1945); Purask1 County: Grand Chain | (Blanchard 1921); RicHLAND COUNTY: | (Cope 1888) ; Sr. CLain County: (Hurter » 1893); WapasH County: Mount Carmel : (Yarrow 1882a). : | 1961 November, SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 223 Fig. 210.—An adult Cemophora doliata from Calhoun County, Florida. The groundcolor is gray or white; the blotches are bright red, heavily margined with black. The venter is plain white. (Photo by Isabelle Hunt Conant.) Cemophora Cope One monotypic species of Cemophora is known in southeastern United States. The majority of American herpetologists now as- sign the name C. coccinea (Blumenbach) to this species. Other authors, however, re- gard the name doliata Linnaeus as applica- ble to the scarlet snake. Cemophora doliata (Linnaeus) Scarlet Snake Coluber doliatus Linnaeus 1766:379 (type lo- cality: Carolina; revised to vicinity of Charleston, South Carolina, by Schmidt 1953). Cemophora doliata doliata, Bennett 1953:164. Diagnosis.—A small, moderately slender snake (less than 600 mm. in total length), fig. 210, with 19 rows of smooth scales; anal plate entire; rostral scale pointed and wart- like; loreal present; supralabials 6+ 6; in- fralabials 6 to 8 on each side; preoculars 1+ 1, postoculars usually 2+2; top of snout red; groundcolor above gray, white, or yellow, with broad, black-bordered red rings; venter immaculate white or yellow- ish white. Variation.—Details of sexual and onto- genetic variation are unknown for the spe- cies in this part of its range. A single male of this species (SIU 542) is known from Illinois. This specimen has 19 scale rows, 161 ventrals, 41 caudals, 6 + 6 supralabials, 6 + 7 infralabials, 1 + 1 preoculars, 1-+2 postoculars, and 1-2 temporals on each side, 19 body blotches, 8 tail rings, and a total length of 448 mm., roy ae | | 4 Sage ae Spirt a A < laa ¢ : | ia | Trap S fete Fig. 211.—Distribution of Cemophora dolia- ta. The lower map depicts the total known range of the species in the United States. the tail comprising 14.7 per cent of the total length. The groundcolor dorsally is dark gray, the red saddles appearing lighter; the venter is unmarked. Habits.—The scarlet snake presumably feeds on lizards, other snakes, and young mice. This small constrictor is fossorial and 224 apparently nocturnal. No information is available on the number or dimensions of the eggs in the northern part of the range of the species. Illinois Distribution.—The sole Illinois specimen bears the label “Wolf Lake Swamp, Union Co., Illinois, July 26, 1942, F. R. Cagle.” It was mistakenly cataloged as Lam- propeltis triangulum syspila. Bennett (1953), at my suggestion, reported the error and re- corded the genus for II]linois. Despite heavy collecting in the area, this specimen remains the only record for the state, fig. 211. There is growing doubt in the minds of herpetol- ogists at Southern Illinois University that the specimen actually came from Wolf Lake. I am inclined to accept the record as valid, in view of similar circumstances in Indiana and Missouri, where many years elapsed before the initial records were substantiated by additional specimens, and in view of the failure of many hundreds of collectors over many decades to find Tantilla gracilis and Natrix cyclopion in the Wolf Lake area. Cemophora probably occurs on the slopes of Pine Hills rather than in the swamp. Fig. 212.—A subadult Tantilla gracilis hallowelli from Union County, Illinois. The color above is tan or light gray with a black cap on the head; below, salmon-pink. ILtinois NATURAL History SurvEY BULLETIN Vol. 28, Art. I Tantilla Baird & Girard This New World genus contains, in the United States, nine species, some of which have several subspecies. One species is found in southwestern Illinois. Tantilla gracilis hallowelli Cope Northern Flat-Headed Snake Tantilla hallowelli Cope 1860a:77 (type local- ity: Manhattan, Kansas). Tantilla gracilis hallowelli, Smith & Burger 1950:2. Diagnosis.—A diminutive snake (largest Illinois specimen 203 mm. in total length), fig. 212, with 15 rows of smooth scales; flat- tened head, little wider than neck; frontal about four times the size of either supraocu- lar; no loreal; preoculars 1 + 1, postoculars 1+ 1; supralabials usually 6+ 6; infra- labials usually 6+ 6; eyes minute; anal plate divided; ventrals 121 to 132; caudals 42 to 51; color above tan or yellow-brown, with the top of the head darker, sometimes with a definite cap; venter salmon or orange November, 1961 medially, becoming white laterally and an- teriorly. Variation.—The male northern flat- headed snake has fewer ventrals, more cau- dals, and a proportionately longer tail than the female. The juvenile tends to have a darker and more conspicuous head cap than the adult. Only 13 specimens of this snake have been found in Illinois. Eleven are available for study. Four males from Union County vary as follows: ventrals 121 to 124 (average 123), caudals 49 to 51 (average 49.7), tail length 21.1 to 23.7 (average 22.7) per cent of total length. Four females from the same locality have characters as follows: ventrals 125 to 132 (average 129.2), caudals 42 to 47 (average 43.7), tail length 18.4 to 20.4 (average 19.4) per cent of total length. Fig. 213.—Distribution of Tantilla gracilis. Hatching indicates the presumed range of the subspecies Aallowelli in Illinois; solid circles indicate localities represented by specimens examined during this study; the open circle indicates a locality represented by a published record believed to be valid. The lower map depicts the total range of the species in the United States. SMITH: AMPHIBIANS AND RepTILEs OF ILLINOIS 225 Three females from Monroe County vary as follows: ventrals 129 to 132 (average 130.6), caudals 44 to 45, tail length 17.9 to 20.2 (average 19.0) per cent of total length. Scale rows are 15 in all 11 snakes; supra- labials are 5+6 in one, 6+6 in seven, 6+7 in two, 7+ 7 in one; infralabials are 6+ 6 in nine, 6+7 in one, and 6+ 5 in one; preoculars are 1 + 1 in nine, post- oculars 1+ 1 in eight, 2+2 in one, and oculars undeterminable in two. Habits.—The northern flat-headed snake, the smallest Illinois snake, is strictly fos- sorial. Specimens are usually found by rais- ing flat rocks in dry talus slides. Although these tiny snakes possess minute poison glands and rear fangs, they are too small to bite man. Their food consists of small ar- thropods. I have not seen the eggs of the species. Illinois Distribution—The available specimens of this snake were found along the relatively arid Mississippi River bluffs in Monroe and Union counties, fig. 213. Neill (19515) recalls having taken a snake of this species in St. Clair County, but it was not saved. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: St. CLair County: near East St. Louis (Neill 19515). Thamnophis Fitzinger Eleven species of Thamnophis, many with subspecies, are found in the United States and Canada. Other species occur in Mex- ico and Central America. Thamnophis sauritus (Linnaeus) Three subspecies of the ribbon snake are recognized in the United States. A western subspecies occurs in Illinois, presumably in- tergrading with the nominate form in the ex- treme southeastern part of the state, al- though there is some likelihood that the in- tergrade population has been recently ex- terminated. Thamnophis sauritus proximus (Say) Western Ribbon Snake Coluber proximus Say 1823:187 (type locality: stone quarry on west side of Missouri River, 226 3 mi. above mouth of Boyer River, Potta- wattamie County, lowa). Thamnophis sauritus proximus, 19084:43, 98-107. Thamnophis proximus, Ditmars 1945:59. Eutania proxima, Kennicott 1855:592. Eutaenia proxima, Davis & Rice 1883a:30. Eutainia saurita proxima, H. Garman 1892: 264-5. Thamnophis proxima, McLain 1899:3. Eutaenia faireyi, Cooper 1860:299. Eurainia saurita faireyi, H. Garman 1892: 264-5. Eutainia faireyi, Hurter 1893:256. Thamnophis proxima faireyi, Hurter 1911:160. Eutaenia saurita, Yarrow 1882a:114. Eutainia saurita saurita nec Linnaeus, H. Garman 1892:264-5 (1). Thamnophis sauritus sauritus nec Linnaeus, Van Cleave 1928:133, 136. Thamnophis sauritus, Necker 1933:8. Ruthven Diagnosis.—A medium-sized, very slen- der snake (largest Illinois specimen 993 mm. in total length), fig. 214, usually with 19- 19-17 rows of strongly keeled scales; ven- trals 163 to 181; caudals 83 to 131; anal plate entire; supralabials usually 8+ 8; in- fralabials usually 10+ 10; preoculars usu- ally 1+ 1, postoculars usually 3 + 3; tail length usually more than 25 per cent of total length; groundcolor usually jet black, with three distinct, longitudinal, light stripes; middorsal stripe orange; lateral stripes greenish white, involving third and fourth scale rows; a pair of prominent, light pari- etal spots nearly always present; venter, la- bials, and chin immaculate greenish white; a light bar on each preocular. Variation—The male of Thamnophis sauritus proximus is longer tailed than the female and has a slightly higher ventral count mean, table 65. Juveniles and adults are similar in color and pattern, but the young are more slender bodied. The most striking geographic variation in T. s. proximus is found in the approach of southeastern Illinois specimens to JT’. s. sauri- tus. In fact, seven specimens from Richland and Wabash counties are perhaps referable to that race, inasmuch as they are more or less typical of eastern specimens in scutel- lation, table 66. All seven are very old and faded, and the colors are therefore not re- liable. They appear to be intergrades, how- ever, showing more brown and less distinct parietal spots than other Illinois specimens of comparable age. Ruthven (19084) never- theless assigned these same specimens to proximus, pointing out that they resembled Intrnors NaturAL History SurvEY BULLETIN Vol. 28, Art. 1 sauritus in several respects. No fresh ma- terial from eastern Illinois is available. When, and if, specimens turn up from this area, it will not be surprising if they are typical JT. s. sauritus in color and pattern features. Specimens taken in the northern half of Illinois show little deviation in scale count averages from those taken in south- western Illinois, table 66. Individual variation in a sample of 40 specimens is as follows: scale rows 18-19-17 in 2.8 per cent of specimens, 19-17-17 in 8.5 per cent, 19-19-17 in 83.0 per cent, 20-19-17 in 5.7 per cent; infralabials 9 + 9 in 7.8 per cent, 9+ 10 in 5.2 per cent, 10+ 10 in 86.8 per cent; preoculars 1+ 1 in 100 per cent; postoculars 2+2 in 2.8 per cent, 2 + 3 in 2.8 per cent, 3 +3 in 77.8 per cent, 3 + 4 in 13.8 per cent, and 4+ 4 in 2.8 per cent. Habits.—This slender and brightly col- ored snake is quick in its movements. It climbs readily and swims rapidly. In the summer it is found around swamps and marsh edges and occasionally in upland woods. In the fall in southern Illinois the western ribbon snake occurs commonly at the bases of rock bluffs, where it apparently hibernates in rock crevices with rattlesnakes, copperheads, and black snakes. Newly cap- tured individuals threaten with their mouths opened wide, but they rarely try to bite. Cap- tives feed readily on frogs and small fish. On one occasion a large specimen ate two smaller ribbon snakes. Data concerning the number of young pro- duced by the female of this ovoviviparous species are meager in Illinois. One female had 12 young in early August. An intergrade ~ T.. s. sauritus X proximus, from adjacent In- — diana, had 11 young on July 17. 3 Illinois Distribution—The range of the western ribbon snake in Illinois is prob- lematical, fig. 215. The species is fairly com- mon along the Mississippi River bluffs and — it is quite common in southwestern Illinois. Elsewhere in the state, it is extremely rare. No recent records are available for the cen- — tral and eastern parts of Illinois, although — such records are available for adjacent Indi- is ana. : 4 This curious situation is not readily — explained, for the scarcity of the species in — the Shawnee Hills cannot be attributed to — extensive cultivation of land or drainage. Although undocumented by specimens, — published records for the following localities — & at oe November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS Fig. 214.—An adult Thamnophis sauritus proximus from Union County, Illinois. groundcolor is black; the middorsal stripe, orange; the lateral stripes and venter are greenish white. The Table 65.—Sexual variation in Illinois Thamnophis sauritus. Figures in parentheses are numbers of specimens. CHARACTERISTIC BAIA Seay ee ta rics boats a Mates (15) Fematces (22) Range Mean Range Mean 166-181 | 172.8 163-177 | 170.1 108-131 | 115.9 83-114 | 100.7 297,2-33.6) 31.0) |24.0-31-9|) 23.3 Table 66.—Geo¢graphic are numbers of specimens. variation in Illinois Thamnophis sauritus. Figures in parentheses CHARACTERISTIC Ventrals LFV Srp ll Le yebet eee a a NorTHWESTERN ILirnots (8) SOUTHWESTERN ILiiNors (22) Range Mean Range Mean .| 170-181 | 172.8 | 166-181 | 173.5 .| 165-172 | 169.3 | 163-177 | 174.4 .| 111-114 | 112.5 108-131 | 114.1 .| 83-103 93.0 9 -114 9955 13122=31 4) 3123 7|29.2-31 6). 30.2 D4 291) 27/12 \2420-30:0) 27.8 RIcHLAND- WaBASH CounTIEs (7) Range Mean 165-173) | 169.3 165-167 | 166.0 120-124 | 121.6 110-111 | 110.3 Biles Son Olam one, SiO Sle 9 eros Per CENT OF Per CENT oF Per CENT OF SPECIMENS SPECIMENS SPECIMENS : WE) 9.1 42.8 : 12.5 9.1 28.6 . 75.0 81.8 28.6 22 Ittinoris NATURAL History SurvEY BULLETIN Fig. 215.—Distribution of Thamnophis sauri- tus. Vertical hatching indicates the presumed range of the subspecies proximus in Illinois; crosshatching, the area of intergradation be- tween the subspecies proximus and sauritus ; solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The species may no longer occur in the middle and eastern counties. The lower map depicts the total range of the species in the United States. Fig. 216—An adult Thamnophis radix radix from Champaign County, Illinois. groundcolor is brown on which are superimposed black markings and three longitudinal stripes. The median stripe is dull orange; the others are yellowish gray. Vol. 28, Art. 1 are believed valid and are indicated on the distribution map by hollow symbols: HAn- cock County: Dallas City (Ditmars 1907); Jersey County: (H. Garman 1892) ; Mapison County: (Hurter 1911). Thamnophis radix radix (Baird & Girard) Eastern Plains Garter Snake Eutainia radix Baird & Girard 1853:34 (type locality: Racine, Wisconsin); H. Garman 1892:266. Eutania radix, Kennicott 1855:256. Eutaenia radix, Hay 1881:738. Tropidonotus radix, S. Garman 1884:23. Tropidonotus ordinatus radix, Boulenger 1893: 211. Thamnophis radix, Ruthven 1908b:70-87. Thamnophis radix radix, Van Cleave 1928: 133, 136. ?Eutaenia vagrans nec Baird & Girard, Davis & Rice 1883a:30. ?Eutaenia vagrans vagrans nec Baird & Gir- ard, Davis & Rice 1883b:39. 2?Eutainia vagrans nec Baird & Girard, H. Garman 1892:268. ?Eutaenia butleri nec Cope, Ditmars 1922:241. 2Thamnophis butleri nec Cope, Necker 1938:3. 2Thamnophis radix butleri nec Cope, Wright & Wright 1952:585. ?Thamnophis, Blaufuss 1943:56. Diagnosis.—A medium-sized, moderately slender snake (largest Illinois specimen 756 mm. in total length), fig. 216, with 19 to 21 anterior and usually 17 posterior rows of strongly keeled scales; 143 to 165 ventrals; 59 to 82 caudals; anal plate entire; supra- labials usually 7 + 7; infralabials 9 or 10 per side; 1 preocular and 3 postoculars per side; proportionate tail length usually less than The November, 1961 25 per cent of total length; groundcolor brown, with three longitudinal light stripes; middorsal stripe orange-yellow and occupy- ing one row of middorsal scales and half of each adjacent row in width; lateral stripes narrower, yellow-gray, and involving the third and fourth scale rows on each side; dark groundcolor on either side of middor- sal stripe, with two rows of alternating black spots or squares; a pair of light occipital dots usually present; venter gray-green, with dark spots at least on edges of ventrals; labials barred with dark. Variation— Males of Thamnophis radix radix have higher ventral and caudal counts and proportionately longer tails than fe- males, table 67. Juveniles and adults are similar in proportions and pattern. SmitH: AMPHIBIANS AND RepTILES OF ILLINOIS 229 Geographic variation in scutellation is rather slight within Illinois, but a reduced ventral count in the northeastern population is suggested, table 68. The five specimens at hand from Madison County have a higher average number of scale rows than northern samples; the sig- nificance of this variation is unknown. A trend toward melanism is found in the northeastern sample, many specimens having rather heavy black spots or streaks on the sides of the ventral scutes. Ventral spotting is less frequent in samples from western and southern Illinois. Specimens exhibiting a bright red-brown groundcolor occur occa- sionally in all parts of the state where the species occurs. May (1952) has described an albinistic specimen from the Chicago area. Table 67.—Sexual variation in Illinois Thamnophis radix radix. Figures in parentheses are numbers of specimens. CHARACTERISTIC a NTCt Spree mat ore oa ae, in Bt Mee Oh gd et Mates (29) Fema.ces (32) Range Mean Range Mean SReie Wear 154-165 | 158.0 143-163 | 152.4 d eaeeaperneats 68-82 74.8 59-70 65.3 Beata obs ZOO =25 5 San Omni 3 =) Seva eile. Table 68.—Geo¢graphic variation in Illinois Thamnophis radix radix. Figures in parentheses are numbers of specimens. East-CeNTRAL Map1son NorTHEASTERN | NORTHWESTERN ILLINOIS County ILLINoIs ILLINoIs (12 Mates, (1 Mate, (11 Mates, (6 Mates, CHARACTERISTIC 14 FemMa_es) 4 FEMALES) 13 FemMALEs) 5 FEMALES) Range | Mean Range | Mean Range Mean | Range | Mean Ventrals | INMall eats enloneexs 154-165 | 159.0 1S Ban Fe a eee 154-160 | 156.6 | 154-163 | 158.3 | Hemralese. = <2): 149-160 | 154.6 149-156 | 152.5 143-163 | 150.3 149-154 | 151.8 Caudals IMIG ee as. .15% 68-82 VEGI SLO ee Sigel eel EROS oes 71-78 74.2 70-74 yore Female........ 60-70 | 65.8 | 67-71 | 68.6 | 59-69 | 64.2 | 65-68 | 66.7 Tail length as per- centage of total ~ length | Migle ss moos) os ET EOSIN a eS 22.6-25.4| 23.9 |20.8-24.8) 23.7 | | Fentale.. 5.5... 19e e254). Qld P20 5—23,,6|.- 22.7 |20.2-23.7| ..21.5 19. 5-22.8| 20.7 230 Other variation in T. r. radix shows no correlation with geography. In 61 speci- mens the anterior scale rows are 17 in 2 per cent of specimens, 19 in 80 per cent, 20 in 5 per cent, and 21 in 13 per cent; scale rows at mid-body are 19 in 74 per cent, 20 in 3 per cent, and 21 in 23 per cent; posterior scale rows are 15 in 8 per cent, 16 in 3 per cent, 17 in 87 per cent, and 18 in 2 per cent. Variation in head scutellation for these 61 snakes is as follows: supralabials 6 + 6 in 1 per cent, 6 + 7 in 1 per cent, 7+ 7 in 73 per cent, 7+8 in 22 per cent, 8+ 8 in 3 per cent; infralabials 8 + 8 in 2 per cent, 8+ 9 in 3 per cent, 9+9 in 22 per cent, 9 + 10 in 27 per cent, and 10 + 10 in 46 per cent; preoculars are 1 +1 in 98 per cent, 1 +2 in 2 per cent; postoculars 1+ 1 in 3 per cent, 2+ 2 in 3 per cent, 2 + 3 in 3 per cent, and 3+ 3 in 91 per cent. Light occipital dots are present on 87 per cent. A specimen from Douglas County (INHS 3009) is anomalous, inasmuch as the lateral stripes encroach on the second scale rows as well as the third and fourth. Habits——The eastern plains garter snake is best known in vacant lots of cities and villages in the state. Comparatively few specimens have been found in remote areas. In the spring, this snake abounds in trashy areas and in meadows and pastures near vil- lages. On wet or cool days, several indi- viduals may congregate under a single ob- ject. Most individuals do not try to bite when captured, but they throw fecal matter that apparently consists largely of digested earthworms. Numerous specimens have been observed eating earthworms. These snakes may eat amphibians and other inver- tebrates also; captives have displayed no interest in insects. Broods of 10, 10, 12, 13, 17, and 27 have been born in the laboratory, most of them in late August. A female killed at Volo on Oc- tober 14 had 12 fully formed young still within her body. Illinois Distribution.—The eastern plains garter snake is extremely abundant in certain muck prairie areas in the northern half of Illinois and it seems to thrive in the most heavily cultivated districts, fig. 217. The species has not been found in many In- diana counties bordering Illinois, probably because of the more forested aspect of these counties. The scarcity of records for west- central Illinois may be because the original Itttnoris NarurAL History SurRVEY BULLETIN Vol. 28, Art. 1 = s —_ le —4 OES SE PEPER WH | NI@ Fig. 217.—Distribution of Thamnophis radix. Hatching indicates the presumed range of the subspecies radix in Illinois; solid circles indi- cate localities represented by specimens ex- amined during this study; open circles, locali- ties represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. prairie areas in this part of the state, rolling and relatively well drained, lacked the ex- tensive prairie marshes typical of much of the Grand Prairie. The southernmost re- cent record of this snake is from a prairie — outlier in Cumberland County. Two old records for southern Illinois (Madison and Wabash counties) are based on USNM specimens collected in the last century. It is likely that the Madison County speci- mens were from a relict colony on a prairie outlier, a colony later exterminated. The Wabash County specimen was probably in- correctly cataloged, and the record is not accepted here. Although undocumented by specimens, published records for the following localities are believed valid; most are shown on the distribution map by hollow symbols: Cook County: Argo (Schmidt & Necker 1935); November, 1961 Arlington Heights (Necker 1939c) ; Berwyn (A. Smith 1949) ; Beverly Hills (Schmidt & Necker 1935); Blue Island (A. Smith 1949); Braeside, Chicago Lawn, Chicago Ridge (Schmidt & Necker 1935) ; Evanston (Necker 1939c); Flossmoor (A. Smith 1949); Forest Park, Homewood (Schmidt & Necker 1935); Kenilworth (A. Smith 1949); La Grange, Lambert (Necker 1939c) ; Longwood, Morgan Park, Palos Park (Schmidt & Necker 1935); Pullman (Necker 1939c); Riverdale, Summit (Schmidt & Necker 1935); Wheeling (Necker 1939c) ; Willow Springs, Winnet- ka, Wolf Lake (Schmidt & Necker 1935) ; Du Pace County: Lombard, Naperville (Schmidt & Necker 1935); West Chicago, Wooddale (Necker 1939c) ; GRuNpy Coun- TY: Diamond (A. Smith 1949); Pequot (Necker 1939c) ; HENry County: Colona (H. Garman 1892); Lake County: Bar- rington, Briggs Lake (A. Smith 1949); Deerfield, Fox Lake (Schmidt & Necker 1935); Highland Park (Necker 1939c); Waukegan (A. Smith 1949); McHenry County: Richmond (Schmidt & Necker 1935); Rock Istanp County: Milan (H. Garman 1892); STEPHENSON CouNTY: Freeport (H. Garman 1892). Thamnophis sirtalis (Linnaeus) Eleven subspecies of Thamnophis sirtalis are recognized in the United States and Canada. The wide-ranging nominate sub- species and a subspecies restricted to the lower western and southern border of Lake Michigan occur in Illinois. Thamnophis sirtalis sirtalis (Linnaeus) Eastern Garter Snake Coluber sirtalis Linnaeus 1758:222 (type local- ity: Canada; revised to vicinity of Quebec by Klauber 1948). Eutania sirtalis, Kennicott 1855:592 (part). Eutaenia sirtalis, Schneck 1882:1008. Eutaenia sirtalis sirtalis, Davis & Rice 1883a: 30 (part). Eutainia sirtalis, Hay 1891:110. Eutainia sirtalis sirtalis, H. Garman 1892: 266-7. Thamnophis sirtalis sirtalis, Ruthven 1908b: 176-86 (part). Thamnophis sirtalis, Hurter 1911:163. Eutaenia sirtalis parietalis nec Say, Cope 1875:41. Eutainia sirtalis parietalis nec Say, H. Gar- man 1892:266-8. Thamnophis sirtalis parietalis nec Say, Ruth- ven 1908a:392. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS Z31 Thamnophis parietalis nec Say, Weed 1923:47. Eutaenia sirtalis obscura, Yarrow 1882a:126. Eutaenia sirtalis dorsalis nec Baird & Girard, Davis & Rice 1883a:30 (part). Eutaenia vagrans nec Baird & Girard, Davis & Rice 1883a:30 (part). Diagnosis.—A medium-sized, moderately slender snake (largest Illinois specimen 1,044 mm. in total length), fig. 218, usually with 19-19-17 rows of strongly keeled scales; ventrals 147 to 165; caudals 61 to 82; anal plate entire; supralabials usually 7 +7; infralabials usually 10 + 10; usually I preocular and 3 postoculars per side; tail length usually less than 25 per cent of total length; groundcolor brown, red-brown, or dark blue-green, with black spots or squares between longitudinal light stripes; middor- sal stripe gray or yellow, on median scale row and halves of adjacent rows; lateral stripes similarly colored involving second and third scale rows, noninterrupted; ven- ter gray-green, with dark spots at edges of most of the ventrals; head usually without paired light parietal dots; labials with dark bars. Variation.—The male of the eastern gar- ter snake has a longer tail and a slightly higher caudal count average than the fe- male, table 69. Juvenile garter snakes are like the adults except that the baby snakes have propor- tionately larger heads. A few very large adults of Thamnophis sirtalis have tails that are proportionately shorter than those of juveniles, but the proportionate tail length averages in large series of adults and of juveniles are almost identical. Geographic variation in scutellation of the eastern garter snake is remarkably slight in Illinois. The means for ventral and caudal counts and the proportionate tail lengths of approximately 40 snakes from eastern IIli- nois and a sample of similar size from the western side of the state vary no more than 1 per cent. Likewise, comparison of these scale counts for specimens from extreme southern and extreme northern Illinois re- veals no geographic variation. The mean ventral and caudal counts are somewhat at variance with those from an Ohio sample (Conant 1938), but they are much closer to those from Ohio than to those of a Nebraska sample of J’. sirtalis parietalis (Hudson 1942). The red pigment in the groundcolor, an Fig. 218—An adult Thamnophis sirtalis sirtalis from Douglas County, Illinois. ILtinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 1 The groundcolor is brown on which are superimposed black markings and three longitudinal tan stripes. Table 69.—Sexual variation in Illinois Thamnophis sirtalis. Figures in parentheses are numbers of specimens. CHARACTERISTIC Wentrals io 5 orice ah Od Ia haem eT Bpnaeas tee Caudals. 3 alleged diagnostic character of parietalis, appears occasionally in populations of T. sir- talis throughout Illinois. Thirty-three per cent of a sample of 12 snakes from north- western Illinois, 42 per cent of a sample of 20 snakes from east-central Illinois, 55 per cent of a sample of 20 snakes from west- central Illinois, and 26 per cent of a sample of 20 snakes from extreme southern Illinois have some red on the sides of the body. In view of the homogeneity of garter snakes in IIlinois in scutellation and in color, there is no basis for including T. s. parie- talis as a part of the Illinois fauna, the nu- merous reports of it and of sirtalis X parie- talis intergrades in the western part of the state notwithstanding. Mates (38) FeMaA_es (54) Range | Mean | Range | Mean Reno a 150-163 | 156.9 147-165 | 153.6 HOS ee ae 70-82 76.3 61-74 67.0 EAC mehr 22.8-26.0) 24.2 |18.0-24.4) 21.7 In pattern, however, there is pronounced geographic variation among garter snakes. within Illinois. Toward the northeast the lateral stripes on the anterior part of the body tend to be interrupted at regular in- tervals by crossbars formed by the fusion of the black spots just above and just below the lateral line. The crossbarred pattern is. sufficiently constant in garter snakes found along the southwestern border of Lake Michigan for the population to be recog- nized subspecifically as semifasciata. Inter- gradation between sirtalis and semifasciata is manifested by the increasing frequencies, toward the northeast, of specimens with the crossbarred pattern. The cline is steep from. west to east, sloped from south to north. November, 1961 Scutellation is apparently identical in the two Illinois subspecies of 7. sirtalis. Indi- vidual variation in 91 specimens of both races is as follows: anterior scale rows are 19 in 95.5 per cent, 20 in 4.5 per cent; scale rows at mid-body are 18 in 5.5 per cent, 19 in 93.5 per cent, 20 in 1.0 per cent; posterior scale rows are 16 in 2 per cent, 17 in 98 per cent; supralabials are 6+ 6 in | per cent, 6+ 7 in 3 per cent, 7+ 7 in 89 per cent, 7 + 8 in 6 per cent, 8+ 9 in | per cent; in- fralabials are 8 + 8 in 3 per cent, 9+ 9 in 7 per cent, 9+ 10 in 11 per cent, 10+ 10 in 73 per cent, 11 + 11 in 3 per cent, 8 + 10 in 3 per cent; preoculars are | + 1 in 100 per cent; postoculars are 2 + 3 in 2 per cent, 3 +3 in 95 per cent, 3 +4 in | per cent, 2+ 4 in 1 per cent, and 4+ 4 in | per cent. =.255 === Fig. 219.—Distribution of Thamnophis sirt- alis. Vertical hatching indicates the presumed range of the subspecies sirtalis in Illinois; horizontal hatching, the presumed range of the subspecies semifasciata; crosshatching, the | ie of intergradation between the two sub- species; solid circles indicate localities repre- ;sented by specimens examined during this eedy: open circles, published records believed to be valid. The lower map depicts the total range of the species in the United States. Sm1TrH: AMPHIBIANS AND REPTILES OF ILLINOIS 233 Habits.—The eastern garter snake, al- though occasionally found in shrubbery and in water, is essentially terrestrial. It occurs in a variety of places but seems to prefer a forest-edge habitat. Most individuals of T. sirtalis bite and void excrement when cap- tured. This species feeds on a variety of animals including frogs, toads, salamanders, earthworms, fish, young birds, and leeches. The number of young per brood varies considerably. A captive female gave birth to 27 young in the laboratory in September. Cagle (1942a) recorded a litter of 53 born in early July. Illinois Distribution.—T. s. sirtalis is generally distributed throughout Illinois ex- cept in the northeastern fourth of the state, where it is replaced by semifasciata, fig. 219. It is relatively uncommon in many parts of central Illinois. Although undocumented by _ specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Knox County: 214 mi. E Galesburg (Adcock 1922); Mapison County: (Hurter 1911) ; Monroe County: 3 mi. N Red Bud (Blanchard 1924b); Prorra County: Pe- oria (H. Garman 1892) ; St. CLair Coun- ty: Belleville (Yarrow 1882a). Thamnophis sirtalis semifasciata (Cope) Chicago Garter Snake Eutaenia sirtalis semifasciata Cope 1892:692-3 (type locality: Des Plaines, Illinois, and Wisconsin). Thamnophis sirtalis semifasciata, P. W. Smith 1956a:81-4. Eutania sirtalis nec Linnaeus, Kennicott 1855: 592 (part). Eutaenia sirtalis sirtalis nec Linnaeus, Yar- row 1882a:123-4. Eutaenia sirtalis nec Linnaeus, Gastman 1884: 89 (I). Thamnophis sirtalis sirtalis nec Ruthven 1908):176-86 (part). Thamnophis sirtalis nec Linnaeus, Weed 1923: 46. Eutaenia sirtalis parietalis nec Say, Davis & Rice 18834:40 (part). Thamnophis sirtalis parietalis nec Say, Weed 192285: Thamnophis parietalis nec Say, Weed 1923:47 (part). Eutaenia sirtalis obscura, Davis & Rice 1883a: 30. Eutaenia sirtalis dorsalis nec Baird & Girard, Davis & Rice 1833a:30. Eutaenia vagrans vagrans nec Baird & Gir- ard, Davis & Rice 1883a:30. Linnaeus, 234 Eutaenia vagrans nec Baird & Girard, Davis & Rice 18834:39 (part). Eutainia vagrans nec Baird & Girard, H. Gar- man 1892:268. Thamnophis, Blaufuss 1943:56. Thamnophis ordinatus, Mertens 1951:13. Diagnosis.—A medium-sized snake, a subspecies (largest Illinois specimen 905 mm.) of Thamnophis sirtalis, differing from T. s. sirtalis only in markings; lateral stripes on anterior part of body interrupted at regular intervals by black crossbars, which are formed by fusion of the black spots just above and just below the lateral stripe on each side of body, fig. 220. Ittrnors NaturRAL History SuRVEY BULLETIN Vol. 28, Art. 1 Variation.—Sexual and ontogenetic vari- ation are apparently identical in JT. s. sir- talis and semifasciata and are described in the account of J. s. sirtalis. Geographic variation in the Chicago gar- ter snake consists of a clinal reduction to- ward the west and south in the frequency of snakes with black crossbars. In northwest- ern Illinois the area in which typical sirtalis replaces typical semifasciata is probably no more than 40 miles in width. In central Illi- nois the area of intergradation is as much as 100 miles wide. Crossbars in 118 speci- mens of semifasciata and 45 intergrades have been arbitrarily classified in table 70 Fig. 220.—An adult Thamnophis sirtalis semifasciata from Lake County, Illinois. The groundcolor is brown on which are superimposed black markings and three longitudinal tan stripes. Table 70.—Geographic variation in crossbarred pattern in Illinois Thamnophis sirtalis semifasciata and T. s. sirtalis X semifasciata intergrades, expressed in per cent. Figures im | parentheses are numbers of specimens. CROSSBARRED PATTERN T. s. sirtalis X T. s. semifasciata (118) semifasciata (aan 59 | 22 a, 40 4 38 — —_— = _ a ‘ ’ ' November, 1961 as “Prominent” if more than three crossbars interrupt the lateral stripe on each side of the body and if the crossbars are readily discernible, ““Weak” if only one to three crossbars interrupt each lateral stripe or if all the crossbars are dim, and “Absent”’ if the lateral stripes are not interrupted at all. Individual variation for semifasciata in scutellation and in color apparently parallels that described under sirtalis. Habits.—The remarks concerning the habits of J. s. sirtalis apply equally well to those of semifasciata. Pope (19446) records the range in litter size of 12 to 42; and, al- though the provenance of his specimens is not stated, his counts presumably were made on Chicago area snakes. Illinois Distribution.—The Chicago gar- ter snake occurs in typical form from Lake Michigan south to Kankakee and La Salle counties and west to Lee and Winnebago counties, fig. 219. Intergradation with the nominate race occurs from these localities south to Iroquois and Peoria counties and west almost to the Mississippi River. Although undocumented by _ specimens, published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Aux Plaines (Ruthven 1908)) ; Berwyn, Beverly (Schmidt & Necker 1935) ; Deer Grove (Necker 1939c); Evanston (Schmidt & Necker 1935); Glenview (Necker 1939c); Lemont, Morgan Park, Niles Center, Northbrook (Schmidt & Necker 1935) ; Northfield (Yarrow 18822) ; Palatine, Palos Park, Summit (Schmidt & Necker 1935); Du Pace County: Naper- ville (Schmidt & Necker 1935); KANE County: Batavia (Stille & Edgren 1948) ; Lake County: Beach (Schmidt & Necker 1935); Dead River (Necker 1939c); Fox River Grove, Highland Park, Pistakee Lake | (Schmidt & Necker 1935); Sayer Bog (Necker 1939c) ; McHENry County: Rich- mond, Woodstock (Schmidt & Necker 1935). Tropidoclonion Cope | _A single species with three subspecies is | placed in this genus. The few Illinois speci- ne extant are tentatively assigned to the nominate race, in accordance with a recent a by Ramsey (1953). The material from Illinois is at variance with the descrip- SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 235 tion of the subspecies lineatum, particularly in caudal and ventral counts; but our series is not large enough to ascertain the signifi- cance of the differences in these characters. An adequate sample of Illinois specimens is extant in a personal collection but has not been available to me for scale counts. Tropidoclonion lineatum lineatum ( Hallowell) Northern Lined Snake Microps lineatus Hallowell 1857:241 (type lo- cality: Kansas; revised to Kansas City by Schmidt 1953; revised to Fort Leavenworth by Ramsey 1953). Tropidoclonium lineatum, Jordan 1888:361. Tropidoclonion lineatum, Stejneger 1892:504. Tropidoclonio lineatum, Wright & Wright 1952:585. Tropidoclonion lineatum 1953:11, 21, 22. Tropidoclonium lineata, H. Garman 1890: 87-8. lineatum, Ramsey Diagnosis.—A small, moderately slender, burrowing snake (largest Illinois specimen 314 mm. in total length), fig. 221, with 15 to 17 anterior, 17 to 19 mid-body, and 16 to 17 posterior rows of strongly keeled scales; ventrals 135 to 150; caudals 26 to 47; anal plate usually entire; supralabials 5 to 7 per side; infralabials 6 or 7 per side; preoculars 1+1 and postoculars 2+2; tail length less than 20 per cent of total length; ground- color brown above, with three longitudinal gray stripes; middorsal stripe occupying median and adjacent halves of scale rows; lateral stripe involving second scale row an- teriorly, second and third posteriorly; each longitudinal stripe bordered by single series of minute black dots; venter gray or white, with a double series of black half-moon- shaped markings from chin to tip of tail. Variation.—Eight of the 10 specimens of the lined snake at hand are females; the scale counts given by Garman (1890) for three Champaign County specimens presum- ably refer to females, although he did not indicate the sex of his specimens. Ramsey (1953) stated that males have an average caudal count of about 8 scales more than fe- males and that the proportionate tail length mean is greater in males by about 4 per cent. Juveniles are much like adults, but their striped dorsal pattern is perhaps more evi- dent. The black dots bordering the longi- tudinal stripes are somewhat more conspicu- ous in young snakes than in adults. Ituinots NarurAL History SurRVEY BULLETIN Vol. 28, Art. 1 Fig. 221.—A subadult Tropidoclonion lineatum lineatum from Sangamon County, Illinois. The groundcolor above is brown with three varyingly distinct, longitudinal gray stripes; below, white with paired black spots. A summary of the variation for the eight females examined and for Garman’s counts is as follows: the number of ventrals 138 to 150 (average 145.2) ; caudals ?26 to 38 (av- erage ?32.7); supralabials 5+ 5 in 36 per cent of specimens, 6+6 in 46 per cent, 6 + 7 in 18 per cent; infralabials 6 + 6 in 88 per cent, 7+ 7 in 12 per cent; preoculars 1+ 1 in 100 per cent, postoculars 2 + 2 in 100 per cent; anterior scale rows 17 in 50 per cent, 16 in 38 per cent, 15 in 12 per cent; scale rows at mid-body 17 in 27 per cent, 18 in 18 per cent, 19 in 55 per cent; posterior scale rows 16 in 25 per cent, 17 in 75 per cent; tail length 11.6 to 15.3 (average 13.1) per cent of total length. One specimen has a divided anal plate. Data for the two males are as follows: ventrals 144 and 145; cau- dals 40 and 46; supralabials and infralabials 6 + 6; preoculars 1 + 1; postoculars 2 + 2; scale row formula 17-18-16 and 17-19-17; and tail length 16.4 and 16.5 per cent of total length. The scale counts of the [Illinois series agree more closely with those of T'ropido- clonion lineatum annectans, the race occur- ring in the Great Plains from north Texas to central Kansas, than with those of the nominate subspecies, which occurs in Ne- braska and adjacent parts of Kansas, South Dakota, Iowa, and Missouri. When more specimens are available from Illinois, Iowa, and Missouri, it may be necessary to revise the distributional relationships of the sub- species lineatum and annectans. Habits.—The lined snake has the ap- pearance of a diminutive garter snake. It has semifossorial habits; all the specimens available have been found under rocks, logs, or trash. Captured individuals are com- pletely passive. Earthworms are their chief food. Little is known of the reproductive habits of this snake in Illinois. Farther west, how- ever, the seven or eight young per brood are born in August or September. Illinois Distribution—vThe rare lined snake apparently occurs in central Illinois in a few scattered colonies, most of which are probably vacant lot populations within cities, fig. 222. The present distribution of this species east of the Mississippi River is believed to consist of relicts of the Xero- thermic Period. The range of Tropidoclon- ion was probably reduced to scattered small colonies before Illinois was settled; culti- vation and related practices in all likelihood have aided the climatic shifts in reducing the number of populations except those which by accident had cities grow up about them. Not included with the records plotted on the accompanying map is a report of a speci- men seen at Moline. Richard B. Loomis of Long Beach, California, informed me by letter that he captured a lined snake at Moline, Rock Island County, in 1942 but that this snake escaped before it could be preserved. Attempts to find recent specimens of this snake in vacant lots of Urbana have been fruitless. The colony reported there by Gar- man (1890) has probably been destroyed. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: CHAM- November, 1961 Fig. 222.—Distribution of Tropidoclonion lineatum. Solid circles indicate localities rep- resented by specimens examined during this study; the open circle indicates a locality rep- resented by a published record believed to be valid. The lower map depicts the total known range of the species in the United States. a SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS bo oS) ~I PAIGN County: Urbana 1890). (H. Garman Virginia Baird & Girard This North American genus comprises a monotypic and a polytypic species. A west- ern subspecies of the latter occurs in IIlinois. Until recently the generic name Haldea was applied to these species. Virginia valeriae elegans Kennicott Western Earth Snake Virginia elegans Kennicott 1859:99 (type lo- cality: timbered regions of southern IIli- nois). Virginia harpetii elegans, Bocourt 1886:32, figs. 4, 4a. Virginia valeriae elegans, Blanchard 1923a: 351-6. Haldea valeriae elegans, Stejneger & Barbour 19393132. Virginia valeriae, Cope 1875:35. Haldea valeriae, Murrill 1945:23. Haldea valeriae valeriae nec Baird & Girard, Wright & Wright 1952:586. Haldea striatula nec Linnaeus, Cope 1877:64. Potamophis striatulus nec Linnaeus, Van Cleave 1928:133, 136. Diagnosis.—A small, moderately stout- bodied snake (largest Illinois specimen 300 mm. in total length), fig. 223, with 17 rows of faintly keeled scales; ventrals 118 to 132; caudals 31 to 46; anal plate divided; supra- labials 6 + 6; infralabials 5 to 7 on a side; tail length less than 22 per cent of total Fig. 223.—A juvenile Virginia valeriae elegans from Union County, Illinois. The color above is brown; below, greenish white. headed because it is a juvenile. | The specimen pictured here is proportionately large 238 Ittinois NATURAL History SurvEY BULLETIN Vol. 28, Art. I Table 71.—Sexual variation in Illinois Virginia valeriae elegans. Figures in parentheses are numbers of specimens. Mates (10) Fema es (12) CHARACTERISTIC Range | Mean | Range | Mean Wentiate cc, Seer. Sted boas nen SER tne Cele one ice 118-127 | 121.5 | 124-132 | 127.7 Canmdataee Seo Gelso cies Cohn ok os ee ead Bak in 4 oa Sa 38-46 43.3 31-38 34.9 Tail length as percentage of total length................... 18.6-21.4) 20.2 |15.1-18.5| 16.3 Table 72.—Geographic variation in Illinois Virginia valeriae elegans. Figures in paren- theses are numbers of specimens. SouTHERN ILLI- SHAWNEE HIL.Ls Nois NorTH OF (11) SHAWNEE HILts CHARACTERISTIC (11) Range | Mean | Range | Mean Ventrals | Males Sos Phos ea eee eer ot neice crete Wada uh, Eel ava 118-123 | 120.4 | 119-127 | 122.6 Bemiale 05. Ne ye yee OA ee nario Gen Ne 125-132 | 128.5 | 124-131 | 127.0 Caudals Male eee. aie Oke Be a Reo lee inteee 38-46 41.8 44-46 44.8 | Ryevaa rt boeyeina cee yal es ie en Ae nip yg 8 A ey rea ne ana 31-38 34.3 35-36 355 Tail length as percentage of total length in ES Ree ee Noe Ngee ey WL OPA TERT” te IE a eer tA esc 18.6-21.2! 19.8 |20.4-21.4| 20.7 Betis sas a noi hig a eens ol cee ro say cee age {15.1-17.8| 16.0 |15.6-18.5} 16.6 length; head thick; nose rather sharply Individual variation in other features of pointed; dorsum olive, medium brown, or gray-brown, sometimes with minute dark flecks; venter white, sometimes with a few dark flecks on sides of the ventrals. Variation.—In this species the males have a lower average number of ventrals than the females but higher caudal counts and proportionately longer tails, table 71. The juveniles have proportionately larger heads than the adults. The material available lends itself to be- ing placed in three groups, one from the Wabash Border region, one from extreme southern Illinois, and one from the Lower Mississippi Border. Means of ventral and caudal counts for the eastern and western samples are almost identical, and they have accordingly been lumped in order to com- pare them with those for the extreme south- ern Illinois sample, table 72. This compari- son reveals a general trend toward higher average ventral and caudal counts and longer tails in the more northern sample. The northern sample is at the periphery of the range of this species. scutellation for 22 snakes is as follows: scale rows 17 in 91.0 per cent of specimens, 15-17 © in 4.5 per cent, 17-16-17 in 4.5 per cent; supralabials 6+ 6 in 100 per cent; infra- labials 5+ 5 in 4.5 per cent, 5+6 in 4.5 per cent, 6 + 6 in 77.0 per cent, 6 + 7 in 14.0 | per cent; preoculars absent in 91 per cent, a tiny preocular present on at least one side © of the head in 9 per cent; postoculars 1 + 1 in 4 per cent, 1+2 in 4 per cent, 1 +3 in ) 4 per cent, 2 + 2 in 46 per cent, 2+ 3 in 32 ' per cent, and 3 + 3 in 9 per cent. One speci- men has partially fused internasals; the © other 21 specimens have divided internasals. . The dorsal color varies from medium } brown to light brown; the venter is white, — usually with a slight greenish yellow tint but | sometimes with a flesh-color tint. Many _ specimens have minute dark flecks on the » dorsum and small brown dots on the edges » of the ventral plates. Occasionally an indi- vidual is found that has a faint, middorsal | light band. | Habits.—This small snake is semifosso- rial in habits, and it is usually found under i | November, 1961 rocks on wooded hillsides. It has been found abroad at night on several occasions. The most productive collecting sites have proved to be ditches or other excavations into which these reptiles have fallen. Several specimens have been raked up with forest-floor litter in material for Berlese samples. The food of this snake probably consists of soft-bodied arthropods and earthworms. Broods of five tiny young have been born in the laboratory on two occasions, both in mid-August. Illinois Distribution. — The western earth snake is evidently generally distrib- uted south of the Shelbyville Moraine, fig. 224. The label of a specimen, USNM 7303, “Cook County, Illinois,” almost certainly represents an error in cataloging, and the record has been rejected by most authors. Hatching indicates the presumed range of the subspecies elegans in Illinois; solid circles | Fig. 224.—Distribution of Virginia valeriae. indicate localities represented by specimens ‘examined during this study; open circles, localities represented by published records elieved to be valid. The lower map depicts he total range of the species in the United tates. SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS Zao Virginia valeriae elegans is probably more common in the southern third of Illinois than the records indicate, but specimens are difficult to collect because of their preference for forest-floor debris, their small size, and their nocturnal habits. Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAacK- son County: Elkville (Cagle 1942a); Sr. Crain County: Bluff Lake (Hurter 1893). Storeria Baird & Girard Two polytypic species of this North Amer- ican genus occur in the United States. Both are found in Illinois. Storeria dekayi wrightorum Trapido Midland Brown Snake De Kay’s Snake Storeria dekayi wrightorum rapido 1944:57 (type locality: Reelfoot Lake, Tennessee). Storeria dekayii wrightorum, Langebarte} 1947:27-8. Storeria dekayi, Kennicott 1855:592. Iscknognathus dekayi, Boulenger 1893:287. Storeria De Kayi, Hurter 1893:257. Diagnosis——A small, moderately stout- bodied snake (largest Illinois specimen 425 mm. in total length), fig. 225, with 17 rows of strongly keeled scales; ventrals 122 to 142; caudals 43 to 59; anal plate divided; tail length 17 to 26 per cent of total length; supralabials usually 7 + 7; infralabials usu- ally 7+ 7; preoculars usually 1 + 1; post- oculars usually 2+ 2; groundcolor gray or light brown, usually with a dim middorsal light stripe; middorsal stripe with numer- ous narrow dark crossbars, giving the mid- dle of the back a ladder-like appearance, or middorsal stripe with a series of small dark spots or transverse dashes bordering either side; a more prominent dark blotch on ei- ther side of neck just behind the head and a dark spot below each eye; venter pinkish white and unmarked except for fine stippling on the sides of the ventrals. Variation.—Males of the midland brown snake have fewer ventrals but more caudals and longer tails than females, table 73. Juveniles differ from adults and subadults in the possession of a white or light gray collar just behind the head. This collar, sometimes retained in the subadult, is dis- tinctive and suggests a different species. 240 Fig. 225.—An adult Storeria dekayi wrightorum from Douglas County, Illinois. groundcolor is light brown; the spots are dark brown or black. Intinors NaturRAL History SurvVeEY BULLETIN Vol. 28, Art. I The Table 73.—Sexual variation in Illinois Storeria dekayi wrightorum. Figures in parentheses are numbers of specimens. CHARACTERISTIC Tees 122-131 | 126.5 | 127-142 | 133.9 ngy ped? 50-59 | 55.0 | 43-54 | 49.0 ASB > 20.2-25.6| Mates (22) Fema.es (35) | | eee 93.7 |17:7-23.2) 20a Geographic variation in Storeria dekayi within Illinois, as indicated by four samples (extreme northern, eastern, western, and southern Illinois) is not pronounced, but a southward trend toward a reduction in the number of ventrals in males is suggested. This situation can be expressed as an in- creasing degree of sexual dimorphism in ventral counts toward the south, table 74. The frequency of specimens with dark cross- bars on the dorsum, one of the alleged diagnostic characters of S. d. wrightorum, appears to vary geographically. The sam- ples available suggest that the crossbarred condition occurs rarely in northeastern IIli- nois samples and in approximately two-thirds of the snakes from eastern Illinois, but it is usually present on western and southern » Illinois examples. Other variation in a sample of 56 snakes is as follows: scale rows 17 in 100 per cent; supralabials 7 + 7 in 94 per cent, 7 + 6 in © 2 per cent, 7+8 in 2 per cent, 6+ 6 in 2 ” per cent; infralabials 7 + 7 in 90 per cent, 7+.8 in 4 per cent, 7+6 in 2 per cent, 6 + 6 in 4 per cent; preoculars 1 + 1 in 98° per cent, 2+ 1 in 2 per cent; postoculars - 2+2 in 85 per cent, 2+3 in 8 per centy 2+ 1 in 6 per cent, 3+ 3 in 1 per cent. Despite the low frequency of eastern speci- mens with typical wrightorum dorsal pat- terns, table 74, these snakes are nevertheless | referable to wrightorum on the basis of the sums of ventral and caudal counts and the a N, November, 1961 SmitTH: AMPHIBIANS AND REPTILES OF ILLINOIS 241 Table 74.—Geographic variation in Illinois Storeria dekayi wrightorum. NorTHEASTERN East-CENTRAL West-CENTRAL SOUTHWESTERN a oe ; ILirNots* | ILuinots* ILLrvots* Range Mean Range Mean Range Mean Range Mean Ventrals 112 126-130 | 128.4 | 125-131 | 126.8 | 124-130 | 126.8 | 122-125 | 124.0 iHemale.s... > 131-136 | 132.6 | 128-141 | 133.7 | 130-142 | 134.8 | 129-141 | 133.6 Difference... .. 4-6 4.2 3-10 6.9 6-12 Wes 7-16 10.0 Caudals Bere ress cis 53-57 54.6 51-58 55.1 50-58 54.6 53-59 551 ewaade tks 5! uf 47-50 48.3 43-54 48.5 45-53 49.0 43-52 47.6 Sum of ventrals and aula Seen st vers sts fen 178-186 | 182.2 | 174-193 | 181.9 | 175-195 | 183.3 | 177-187 | 181.0 Per CENT OF Per CENT OF Per CENT OF Per CENT OF SPECIMENS} SPECIMENS} SPECIMENST SPECIMENST Dorsal pattern crossbarred...... 0) 66 79 90 Dark bar on anter- ior temporal...... 89 100 93 84 *Data based on 5 males and 3 females in northeaste 7 males and 10 females in west-central Illinois, and 4 mal 7Data based on 9 specimens in northeastern Illinois, central Illinois, and 39 specimens in southwestern Illinois. high percentage of specimens with dark bars on the anterior temporals. An albinistic subadult was captured in Charleston, Coles County, in 1942. This specimen, which was not preserved, was cream colored and had pink dorsal spots. Habits.—This small snake occurs in for- est and prairie habitats and on both flood- plains and uplands. It has been found most frequently under debris in urban vacant lots and in forest-edge habitats, such as partially wooded pastures and parklike groves. An unusual concentration of several dozen snakes was found along the highway near Fountain Bluff, Jackson County, in October of 1952. These snakes had evidently con- gregated along the highway shoulder to hi- | bernate, and they had probably moved into this site from adjacent cultivated fields on | the Mississippi River floodplain. S. dekayi : feeds primarily on earthworms. Pope - (19446) recorded that it eats newly trans- formed toads. : rn Illinois, 6 males and 12 females in east-central Illinois, es and 9 females in southwestern Illinois. _ : 29 specimens in east-central Illinois, 19 specimens in west- Captive females from central Illinois have given birth to broods of 5, 6, 12, 23, and 17 young in late July or August. Cagle (1942) reported a southern Illinois specimen had 8 young in early August, and Pope (1944) recorded a brood of 24 young born August 1 to a female from Cook County. Illinois Distribution—De Kay’s snake is abundant in all parts of Illinois, fig. 226. The difficulty in obtaining specimens by con- ventional collecting techniques accounts for the gaps on the accompanying map. Although undocumented by specimens, published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Aux Plaines (Yarrow 1882a) ; Berwyn, Beverly Hills (Schmidt & Necker 1935); Braeside, Edgebrook, Elmwood Park, Homewood, Lambert (Necker 1939c); Longwood, Pullman, Riverdale, Summit, Willow Springs (Schmidt & Neck- er 1935); Englewood (H. Garman 1892) ; 242 Fig. 226.—Distribution of Storeria dekayi. The subspecies wrightorum occurs through- out Illinois. Solid circles indicate localities represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Du Pace County: Downers Grove, Ingal- ton (Schmidt & Necker 1935); Naperville (Necker 1939c); KANE County: Batavia, West Dundee (Stille & Edgren 1948); LAKE County: Pistakee Lake (Schmidt & Necker 1935); Sayer Bog (Necker 1939c) ; Peoria County: Peoria (H. Garman 1892); Witt County: New Lenox (Schmidt & Necker 1935); Wooprorp County: Kappa (H. Garman 1892). Storeria occipitomaculata occipitomaculata (Storer) Northern Red-Bellied Snake Coluber occipito-maculatus Storer 1839:230 (type locality: Amherst, Massachusetts). Stereria occipito maculata, Kennicott 1855:592. Storeria occipitomaculata, Yarrow 1882a:129. Storeria occipitomaculata occipitomaculata, Pope 1944b:201-4. Storeria occipito-maculata, Weed 1922:87. Ittrinors NaruraAt History Survey BULLETIN Vol. 28, Art. 1 Storeria occipito-maculata occipito-maculata, Trapido 1944:20-33. Diagnosis.—A small, moderately slender snake (largest Illinois specimen 311 mm. in total length), fig. 227, with 15 rows of strongly keeled scales; ventrals 117 to 130; caudals 41 to 54; anal plate divided; tail length 20 to 26 per cent of total length; supralabials 6+6; infralabials usually 7+ 7; preoculars usually 2 + 2; postoculars usually 2+ 2; groundcolor above black, gray, or brown, with three light spots just behind head, sometimes with a light mid- dorsal band; ventral color deep red or pale orange; usually a small but conspicuous light blotch on the fifth supralabial. Variation.— Males of the northern red- bellied snake have higher caudal counts, pro- portionately longer tails, and lower ventral counts than females, table 75. Juvenile snakes tend to have more distinct occipital — light spots than adults. Too few juvenile specimens are available to permit discerning other ontogenetic variation. No definite clinal variation has been dis- cerned in the small series available for study. The 32 specimens for which scale counts have been made are separable into a northern and a southern Illinois sample; the scutella- tion data for the two samples are offered separately, table 76, for what they may be worth. In other features of scutellation, indi- vidual variation for the 32 specimens is as follows: scale rows 15 in 91 per cent of specimens, 16-15-15 in 3 per cent, 15-15-14 in 3 per cent, and 14-15-13 in 3 per cent; supralabials 5 + 6 in 4 per cent, 6 + 6 in 74 per cent, 6+7 in 22 per cent; infralabials © 7+7 in 84 per cent, 7+ 8 in 13 per cent, 8 + 8 in 3 per cent; preoculars 2 + 2 in 93.0 per cent, 1 +2 in 3.5 per cent, 2 +3 in 3.5 per cent; postoculars 2 + 2 in 100 per cent. Color in the 32 specimens is sufficiently : variable to suggest two different species of — snakes, if the extremes are compared. Al- though specimens that are intermediate in — color occur, the majority of the Illinois speci- mens tend to be separable into two color — phases. In the more common phase the snakes are dark gray to almost black above and have a sharply delineated red ventral color. In this phase there is often a light middorsal band that is sometimes margined — with dark flecks. In the other phase the November, 1961 SmMirtrH: AMPHIBIANS AND REPTILES OF ILLINOIS 243 snakes are tan or red-brown, with an orange ital light spots are less prominent than on ventral color that tends to merge gradually the dark phase. If two color phases are rec- with the brown color of the sides; the occip- ognized, the phenomenon is of limited geo- ‘ Fig. 227,—An adult Storeria occipitomaculata occipitomaculata from Piatt County, Illinois. The groundcolor above is grayish black or red-brown; below, red or orange. Table 75.—Sexual variation in Illinois Storeria occipitomaculata occipitomaculata. Figures in parentheses are numbers of specimens. Mates (12) FeMALes (19) CHARACTERISTIC eae | aes eee Range Mean | Range | Mean CRTINEEUISS oo SS ke Ono GO cle ce RCE Seen ee eres ee 117-126 | 121.5 121-130 | 125.6 ME eae: ee ein Gene oa dats Aw dean died obs 47-54 S120 41-49 44.5 Tail length as percentage of total length................... 22.0-25.8| 24.1 |19.9-24.4| 21.4 Table 76.—Geographic variation in Illinois samples of Storeria occipitomaculata occipito- maculata. Figures in parentheses are numbers of specimens. NorTHERN SouTHERN ILLINOIS ILLINOIS (5 MAteEs, (7 MALEs, CHARACTERISTIC 8 FEMALES) 12 FemMaAces) Range Mean Range Mean Ventrals NE MRS Steere Rist Ace o see nici s Saar ee ene ces 117-126 | 121.0 | 119-126 | 122.0 MARE en Pe aL eA eth ees 2 < Bea, 6-H ace Nooo 123-130 | 126.5 | 121-128 | 124.9 Caudals ee EE Pe en NT Acne weed « odele swe 48-56 52.2 47-53 50.2 EBLE TEENS SATA ah peli ieee ena eo 41-47 44.7 41-49 44.4 INSTT, haga hee kee So RNS ate ry el 22.0-25.8)| 24:3 |22.8—24.8| 23.9 Perera hake. toon oF Bue i a a ye LEO Da eee LG 9-84.24). 2h 244 graphic significance, as snakes of each type have been found together on several occa- sions. The material available, however, sug- gests that the darkly pigmented form (hence more sharply bicolored snakes) is the one that occurs more frequently in northern IIli- nois; 11 of 12 specimens from the northern part of the state are dark, whereas 15 of 20 specimens from the southern part of the state are dark. Some specimens have numerous dark dots or dashes outlining the middorsal light stripe and also have light flecks on the lowermost row of scales and adjacent ventral edges sep- arated from the red ventral color by a row of dark spots. The width of the red ventral color varies; it depends on how far ventrad the dorsal color encroaches. The red ventral color tends to be narrower in the northern than in the southern specimens. Habits.—This small snake is similar to Storeria dekayi wrightorum in most respects. Although it is sometimes found in pastures and wet meadows, it usually inhabits wooded areas. On two occasions individuals have been seen climbing in vegetation above the ground. Captive specimens, according to Pope (19444), feed on earthworms and slugs. The broods are small and probably are born in August or September. A cap- tive specimen gave birth to 14 young in early September. Illinois Distribution.— The northern red-bellied snake is a forest species, and its occurrence in all parts of Illinois, fig. 228, including predominantly prairie areas, is sur- prising, particularly in view of its limited occurrence in Indiana and Ohio. Trapido (1944) regarded the only central Illinois lo- cality known to him (Menard County) as doubtful and suggested that the species was absent in the steppe peninsula of LIllinois, Indiana, and Ohio. Recent records show that the species occurs throughout Illinois but it is distinctly uncommon except in the forested morainal region of Cook and Lake counties. Although undocumented by _ specimens, published records for the following localities are believed valid; most are indicated on the distribution map by hollow symbols: Cook County: Braeside (Schmidt & Necker 1935); Evanston (Trapido 1944); Niles Center, Palos Park (Schmidt & Necker 1935); River Forest (Weed 1922); Thatcher Woods (Trapido 1944); Willow Ittrinots NarurAL History SurRVEY BULLETIN Vol. 28, Art. 1 Springs (Schmidt & Necker 1935); Mec- Lean County: Normal (H. Garman 1892) ; Menarp County: Athens (Trapido 1944); Union County: Anna (H. Gar- man 1892). STL Fig. 228.—Distribution of Storeria occipito- maculata. The subspecies occipitomaculata apparently occurs in wooded areas throughout Illinois. Solid circles indicate localities repre- sented by specimens examined during this study; open circles, published records believed — to be valid. The lower map depicts the total range of this widespread species in the United — States. Natrix Laurenti Nine species, several with subspecies, of — this world-wide genus occur in the United — States and Canada. Ten species and sub- — species are known in Illinois. SS + Natrix cyclopion cyclopion (Duméril, Bibron, & Duméril) Green Water Snake ’ Tropidonotus cyclopion Duméril, Bibron, & Duméril 1854:576 (type locality: New Or- leans, Louisiana). a Natrix cyclopion, Jordan 1888:194. i] ee November, 1961 SmirH: AMPHIBIANS AND REPTILES OF ILLINOIS Fig. 229.—An adult Natrix cyclopion cyclopion from Harris County, Texas. The ground- color is usually olive; the rather indistinct pattern, brown or black. Hunt Conant.) Natrix cyclopion cyclopion, Curran & Kauffeld 1937:261. Tropidonotus cyclopium, Yarrow 1882a:137. Nerodia cyclopium, H. Garman, 1892:271-2. Natrix cyclopium, Cope 1892:673. Diagnosis.—A large, heavy-bodied water snake (largest Illinois specimen 1,000 mm. in total length), fig. 229, with 23 to 29 an- terior and 21 posterior rows of strongly keeled scales; ventrals 141 to 144; caudals 59 to 68; anal plate divided; supralabials usually 8 + 8; infralabials 10 to 13 on each side; preoculars | or 2; postoculars 2 or 3 on each side; suboculars always separating eye from supralabials; groundcolor greenish brown or olive-brown, with approximately 50 narrow, dim black crossbars; ventral color predominantly dark brown posteriorly and blotched with semicircles and squares of yellowish white. Variation.—Scale counts for the three females and one male of the green water snake available from Illinois are as follows: scale rows 29-27-21, 27-27-21, 27-29-21, and 27-24-21; ventrals 142, 141, 143, and 144; caudals 59, 61, 62, and 68; supralabials 8 + 8 in three specimens, 8 + 9 in one; in- fralabials 10+ 10, 13+ 11, 12+ 12, and 11 + 11; tail length 21.8, 19.8, 22.6, and 21.0 per cent of total length. The dorsal pattern is dim on all specimens, and the crossbars cannot be counted with accuracy. Habits—No information is available concerning the habits of Natrix cyclopion in _the northern part of its range. On the Gulf Coast, this large water snake inhabits lakes and swamps. Its food consists of fish and amphibians. Like most of the large water snakes, it is pugnacious in behavior. The young are surprisingly large at birth. (Photo by Isabelle The size of the brood varies with the age and size of the mother snake. Hlinois Distribution—The green water snake, N. c. cyclopion, is known in Illinois Fig. 230.—Distribution of Natrix cyclopion. Hatching indicates the presumed range of the subspecies cyclopion in Illinois; solid circles indicate localities represented by specimens examined during this study; the open circle indicates a locality represented by a published record believed valid. The lower map depicts the species range in tne United States. 246 only from the extreme southern part of the state, fig. 230. Until quite recently the spe- cies was known here by only three CNHM specimens, collected at Olive Branch in 1907, and one equally old USNM specimen bearing the label “southern Illinois.”’ Con- siderable field work by many different col- lectors in extreme southern Illinois failed to yield additional specimens until late 1956, when a juvenile was found at Pine Hills Recreation Area in Union County (Keiser 1958). Since that time nearly a dozen speci- mens have been collected at the same local- ity, but unfortunately they have not been available to me for study. The reasons for the relative abundance of this snake at pres- ent and its apparent rarity prior to 1956 are not known. Although undocumented by specimens, a published record for the following locality is believed valid and is indicated on the dis- tribution map by a hollow symbol: UN1on County: Bluff Lake (H. Garman 1892). Natrix erythrogaster Forster Four subspecies of the copper-bellied water snake are recognized, two of which occur in Illinois. An eastern race traverses ILttinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 1 extreme southern Illinois, intergrading with a Gulf Coast race in the Mississippi River valley. Natrix erythrogaster flavigaster Conant Yellow-Bellied Water Snake Natrix erythrogaster flavigaster Conant 1949; 2, fig. 3 (type locality: Frenier Beach, St. John the Baptist Parish, Louisiana). Tropidonotus sipedon erythrogaster nec For- ster, Yarrow 1882a:136 (1). Nerodia sipedon erythrogaster nec Forster, H. Garman 1892:269-71 (I). Natrix fasciata erythrogaster nec Cope 1900:977 (1). Natrix sipedon erythrogaster nec Forster, Jor- dan 1929:241 (1). Natrix erythrogaster erythrogaster nec For- ster, Conant 1938:71 (I). Nairix sipedon erythro-gaster nec Forster, Hur- ter 1893:257 (I). Forster, Diagnosis.—A large, heavy-bod‘ed water snake (largest Illinois specimen 1,316 mm. in total length), fig. 231, usually with 23 anterior and 17 posterior rows of strongly keeled scales; ventrals 145 to 156; caudals 59 to 84; anal plate divided; 8+ 8 supra- labials; usually 10+ 10 infralabials; usu- ally 1 preocular and 3 postoculars on each side; groundcolor (except in juveniles) uni- Fig. 231. County, Illinois. The groundcolor above is black, dark brown, or very dark olive-gray; below, orange and black in neglecta and yellow in flavigaster. An adult Natrix erythrogaster neglecta X flavigaster intergrade from Alexander : : : | November, 1961 SmitH: AMPHIBIANS AND REPTILES OF ILLINOIS 247 Table 77.—Sexual variation in Illinois Natrix erythrogaster. Figures in parentheses are numbers of specimens. CHARACTERISTIC TD EICIZIE, «5 alata EEE ES pe ena a BA formly dark brown or black above, yellow below; venter usually unmarked except for slight encroachment of dark dorsal color on lateral edges of ventral scutes; groundcolor of juveniles gray, with 29 to 35 closely crowded black dorsal blotches; venter of juveniles yellowish white, with a narrow dark transverse bar bordering each ventral scute. Variation—Males of Natrix erythro- gaster have longer tails than females and accordingly have higher caudal counts. Since lepidosis in the two Illinois races, neglecta and flavigaster, is identical, data on sexual dimorphism for these races are combined in table 77. The baby snakes are blotched; the sub- adults become uniformly dark above and yel- low below. Traces of the blotched pattern are retained in occasional specimens 700 mm. in total length. The venter is usually un- marked, except for the lateral edges of the ventral scutes in specimens 500 mm. or more in length and in juveniles. Geographic variation in color and pattern is rather pronounced in this snake. The more northern specimens are yellow below, with the dark groundcolor of the upper parts encroaching a short distance on each posterior ventral. Anteriorly the ventrals are plain. In a series from extreme south- western I\linois some specimens have this pattern type and some have a pattern in which the venter is orange and the dorsal color traverses the venter, reducing the ven- tral color to a median series of orange semilunar markings. Other specimens in the series are approximately intermediate but show a more pronounced influence of the latter pattern type. These extreme south- western Illinois specimens are intergrades between neglecta and flavigaster. Individual variation in scutellation for N. e. flavigaster and N. e. neglecta is uni- modal, and therefore the counts have been Mates (17) FeMALEs (18) Range | Mean | Range | Mean ey sat eee 67-84 78.2 59-72 67.2 BS oper z 21.4-25.8] 23.8 |19.423.7| 21.4 summarized as follows for the 35 Illinois specimens of WN. erythrogaster studied: ventrals 145 to 156 (average 150.5); an- terior scale rows 19 in 3 per cent of speci- mens, 21 in 13 per cent, 22 in 11 per cent, 23 in 73 per cent; scale rows at mid-body 20 in 3 per cent, 21 in 6 per cent, 22 in 17 per cent, 23 in 65 per cent, 24 in 3 per cent, and 25 in 6 per cent; posterior scale rows 16 in 11 per cent, 17 in 68 per cent, 18 in 16 per cent, 19 in 5 per cent; supralabials 8 + 8 in 100 per cent; infralabials 10+ 10 in 87 per cent, 11+ 11 in 13 per cent; preoculars 1+1 in 90 per cent, 1 +2 in 5 per cent, 2+2 in 5 per cent; postoculars 2 + 3 in 8 per cent, 3 + 3 in 78 per cent, 3 + 4 in 11 per cent, and 3+ 5 in 3 per cent. Habits.—Like the green water snake, this large water snake shows a preference for the quiet waters of ponds, lakes, and swamps. Cornered individuals strike vi- ciously and when captured excrete foul- smelling material on the collector. At Horseshoe Lake, Alexander County, this snake congregates in numbers at the spill- way, where it captures the fish carried over the retaining wall. Catfishes frequently are found in the stomachs of yellow-bellied water snakes, which eat frogs and probably crayfish also. The yellow-bellied water snake apparently leaves hibernation early in the spring; active specimens have been seen the first part of March. Cagle (1942a) records copulation of these snakes in May and the presence of 28 large ovarian eggs in a female. The young cap- tured in the fall are considerably smaller than new-born individuals of N. cyclopion. Illinois Distribution—The range of N. e. flavigaster in its typical form, as indi- cated by the few available specimens, is puzzling, fig. 232. Although the distribution of this subspecies centers in the lower Mis- sissippi River valley, all of the Illinois speci- mens of seemingly pure flavigaster are from 248 north of the Shawnee Hills region. The ex- treme southwestern I]linois specimens which could more logically be expected to display flavigaster characters are actually neglecta X flavigaster intergrades. N. e. flavigaster, at least formerly, extended up the Illinois River. Conant (1949) viewed Garman’s Peoria record with doubt, but I once ex- amined a specimen of flavigaster, in the col- lection of H. J. Van Cleave, labeled “Ha- vana, Illinois.” Havana is only a few miles south of Peoria. This specimen has since been lost, but others are extant from Cal- houn County, the eastern border of which is on the Illinois River. Specimens from the Mississippi River floodplain (Alexander to Jackson counties) are neglecta X flavigaster. Fig. 232.—Distribution of Natrix erythro- gaster. Vertical hatching indicates the pre- sumed range of the subspecies flavigaster in Illinois; horizontal hatching, the presumed range of the subspecies neglecta; crosshatch- ing, the area of intergradation between the two subspecies; solid circles indicate locali- ties represented by specimens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Ittinors NaturAL History Survey BULLETIN Vol. 28, Art. I Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: JAcK- son County: Carbondale, Crab Orchard (Cagle 1942a); Pror1a County: Peoria (H. Garman 1892) ; Unton County: Anna (H. Garman 1892). Natrix erythrogaster neglecta Conant Northern Copperbelly Red-Bellied Water Snake Natrix erythrogaster neglecta Conant 1949:5, fig. 1 (type locality: 3 mi. E Mount Victory, Hardin County, Ohio). Tropidonotus sipedon erythrogaster nec For- ster, Yarrow 1882a:136 (1). Nerodia sipedon erythrogaster nec Forster, H. Garman 1892:269-71 (1). Natrix sipedon erythrogaster nec Forster, Jor- dan 1929:241 (I). Natrix erythrogaster erythrogaster nec For- ster, Conant 1938:7 (I). Natrix sipedon erythro-gaster nec Forster, Hurter 1911:155 (1). Diagnosis.—A subspecies of Natrix ery- throgaster (largest Illinois specimen 1,082 mm. in total length), fig. 231, differing from N. e. flavigaster in color and pattern as fol- lows: groundcolor above black, below bright orange; dark groundcolor of dorsum en- croaching well onto the venter; orange ven- tral color usually reduced posteriorly to a median series of narrow, orange, semilunar markings. Variation.—Sexual and ontogenetic vari- ation in N. e. neglecta parallels that in N. e. flavigaster. The juvenile blotched pattern appears to be lost at a smaller size in neg— lecta, however, probably because this sub- species has a more intense black pigment on — the dorsum. Individual variation for the species is as described in the discussion of N. e. flavi- gaster. , Habits—The northern copperbelly is similar in habits to the yellow-bellied water snake. East of Illinois it frequents bogs. Illinois Distribution—The northern copperbelly is apparently uncommon in IIli- nois, fig. 232. Although few specimens have been collected, this subspecies probably oc- curs throughout the lower Wabash and Ohio River valleys. The northernmost rec- ord, from an island in the Mississippi River, suggests a relict distribution elsewhere. November, 1961 Natrix grahami (Baird & Girard) Graham’s Water Snake Regina grahamii Baird & Girard 1853:47 (type locality: Rio Salado; revised to Salado Creek, Bell County, Texas, by Schmidt 1953); Kennicott 1855:592. Tropidonotus grahami, Hay 1891:113. Natrix grahami, Hay 1892a:589. Trepidonotus grahami, Yarrow 1882a:131. Regina grahami, H. Garman 1892:273-4. Natrix grahami, Hurter 1893:257. Tropidonotus leberis, Davis & Rice 1883a:30. Regina leberis, H. Garman 1889:132. Natrix rigida nec Say, McLain 1899:3. Diagnosis——A medium-sized, moderately stout-bodied water snake (largest Illinois specimen 854 mm. in total length), fig. 233, usually with 20-19-17 rows of strongly SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 249 keeled scales; ventrals 158 to 173; caudals 54 to 67; anal plate divided; supralabials 7, occasionally 8 on each side; infralabials 8 to 10 on each side; groundcolor brown or dark olive above, with a yellow or a light olive-green stripe along either side of the body, involving the lower three scale rows; lateral stripe prominently bordered below by a narrow, irregular black stripe along the outer edges of the ventrals; lateral stripe sometimes bordered above by a dark line; median light stripe 2 to 3 scale rows in width sometimes present; venter yellow or greenish white, with faint median dark line or row of dots on posterior third of belly. Variation.—Males in this species differ from females in the somewhat higher ventral Fig. 233.—An adult Natrix grahami from Cumberland County, Illinois. The groundcolor is olive or grayish brown; the lateral bands and venter are greenish gray or yellowish white. | bers of specimens. Table 78.—Sexual variation in Illinois Natrix grahami. Figures in parentheses are num- | | Mates (15) FemMAL_es (16) | CHARACTERISTIC 1 Range Mean Range Mean _ E ad et aA ete ere fee ee RO ae oe wins 162-175 | 169.1 155-169 | 160.9 audals...... SEL FEBS BG ote eae Rea ah, SESE tee mira oe 60-67 64.0 54—64 57.4 Tail length as percentage of total length................... 17.4-20.4| 19.1 |16.0-20.1] 18.2 250 Ituinois NatrurAL History Survey BULLETIN Vol. 28, Art. 1 Table 79.—Geographic variation in Illinois Natrix grahami. Figures in parentheses are numbers of specimens. NoRTHERN ILtrnors (13) CHARACTERISTIC Ventrals Maleeae es eh oe tik aia ant lets 162-170 APA Sans ibs xu ale eanmeesw nals 158-169 Caudals Mie ito eich a adaectnnw ete eno 62-65 Peiialer eed sada arenes sate e us 57-64 Tail length as percentage of total length AOS eek oa aude ea ees nes 18.3-20.4 eta ee icles ate ake ren eK a ee 17.0-19.7 Range | Mean iB Range | Mean SOUTHERN IL-trNnots (8) CENTRAL Ivirors (11) Range | Mean 165.7 | 171-172 | 171.3 | 167-1753 161.6 | 155-163 | 159.5 | 159-163 | 160.3 63.8 60-67 63.7 63-66 64.5 59.5 54-57 55.7 55-60 57.0 19.5 |18.7-20.4| 19.5 |17.4-19.8] 18.5 18.8 |17.4-20.1| 18.3 N6.0.17.7 1 | and caudal counts and slightly longer tails, table 78. The juveniles differ from the adults in the greater contrast between dorsal groundcolor and color of the lateral stripes. The venter and lateral stripes are more yellowish in young and the occurrence of a middorsal light band, bordered by dark lines, is more frequent in juveniles. There is some evidence that in specimens from the northern part of Illinois the mid- ventral stripe or median series of dark spots on the posterior part of the belly is more prominent than in specimens from the south- ern part. Also, a smaller number of ventrals in northern males is suggested, as shown by a comparison of the means of samples from northern, central, and southern Illinois, ta- ble 79. individual variation in scale rows, labials, and oculars in a sample of 31 specimens is as follows: anterior scale rows 20 in 67 per cent of specimens, 19 in 33 per cent; scale rows at mid-body 19 in 100 per cent; pos- terior scale rows 17 in 92 per cent, 18 in 4 per cent, 19 in 4 per cent; supralabials 7 + 7 in 72 per cent, 7+ 8 in 16 per cent, 8+ 8 in 12 per cent; infralabials 8+ 8 in 8 per cent, 8+ 9 in 16 per cent, 9+ 9 in 52 per cent, 9+ 10 in 16 per cent, 10 + 10 in 4 per cent, 9 + 11 in 4 per cent; preoculars 1 + 2 in 4 per cent, 2+ 2 in 96 per cent; post- oculars 1+2 in 8 per cent, 2 + 2 in 65 per cent, 2 + 3 in 19 per cent, and 3 + 3 in 8 per cent. | Habits.—This striped water snake is found in sluggish water areas such as lakes, river-bottom sloughs, and prairie marshes. Newly captured specimens do not bite, but they are unpleasant to handle because of the quantity of fecal matter they expel. Indi- viduals may be seen basking on rock piles around lakes and on branches overhanging the water. They are shy and usually diffi- cult to catch. Graham’s water snake feeds largely on newly molted crayfish. It feeds on fish and amphibians also. A captive individual of this species had 9 young on August 15. Illinois Distribution.—Although Gra- ham’s water snake occurs in most of Illi- nois, fig. 234, it reaches the eastern limit off its range in this state and has never been re- corded from Indiana. It probably occurs throughout Illinois except for the Wabash and Ohio River counties. Although undocumented by pect published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: Bu- REAU County: Milo (Cope 1900) ; Cook County: Glenview (Schmidt & Necker 1935); FrankKtin County: West Frank- fort (Cagle 1942a); Jackson CouNTY: Murphysboro (Cagle 1942a) ; KanE Coun ty: Geneva (H. Garman 1892) ; Knox eo, Me ae eae ae i ae iia i i a (" re HE i ie cs ——_ =——— —e — Fig. 250.—Distribution of Sistrurus caten- atus. Hatching indicates the presumed range of the subspecies catenatus in Illinois; solid circles indicate localities represented by speci- mens examined during this study; open circles, localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. Inttinois NaturRAL History Survey BULLETIN Arse dy Vol. 28, Art. ia 1935); Epcar County: Paris (Haye 18924); Jackson County: Murphysboro | (Gloyd 1940); Knox County: Galesburg — (H. Garman 1892); Lake County: Deertield (Schmidt & Necker 1935); Me- Lean County: Normal (H. Garman 1892) ; Peorta County: Peoria (H. Gar-— man 1892); Witt County: Crete (Stille & Edgren 1948) ; between Crete and Goode- now (Pope 19446). Crotalus Linnaeus 8 Thirteen species of this North and South American genus occur within the continental _ United States. Most of the species have two or more subspecies. Crotalus horridus Linnaeus Two subspecies of timber rattlesnake are known. The nominate race and an inter-— grade population that exhibits characters of the Gulf Coastal race occur in Illinois. Crotalus horridus horridus Linnaeus Timber Rattlesnake Crotalus horridus Linnaeus 1758:214 (type lo- cality: America; revised to vicinity of New — York City by Schmidt 1953); Davis & Rice 18834a:28. Crotalus horridus horridus, Klauber 1936:246. Crotalus horridus atricaudatus, Pope 1937:224. Crotalus norridus horridus X atricaudatus, Necker 1939b:39. ; Crotalurus cyanurus, Rafinesque 1820:5. Crotalus duressus nec Linnaeus, Kennicott 1855:592. Crotalus durissus nec Linnaeus, Brendel 1857: 254. fi Diagnosis.—A large, stout-bodied - (largest Illinois specimen 1,524 mm. in total — length), fig. 251, with 21 to 27 anterior and 19 to 21 posterior rows of strongly keeled — scales; ventrals 162 to 178; caudals 19 7 30, the last 1 or 2 of which may be divided; — tip of tail with rattle or enlarged “button”; — supralabials 12 to 16 per side; infralabials” 13 to 18 per side; top of head covered with — small asymmetrical scales and two enlarged | plates; pit present between eye and nostril. a on each side of head; groundcolor gray, light yellow, or greenish white above, with 20° to 26 black dorsal blotches or angular rings; tail usually uniform black; venter gray, white, or yellow, with blotching and stippling — present on sides of ventral plates; a mid e dorsal rust-colored stripe occupying 2 to ba scale widths on the anterior part of the November, 196] SmMirH: AMPHIBIANS AND REPTILES OF ILLINOIS i) “I _ Fig. 251.—An adult Crotalus horridus horridus X atricaudatus intergrade from Jackson County, Illinois. The groundcolor may be pale gray, greenish white, or yellowish white; the bands are sooty black; of the body. a vague, middorsal rust-colored stripe is present on the anterior part Table 90.—Sexual variation in Illinois Crotalus horridus. Figures in parentheses are num- bers of specimens. CHARACTERISTIC DETTE TITER RE Ns eee ares « Mates (14) Femates (15) | | Range | Mean | Range | Mean pan aA —— (eal tee age ws 162-174 | 168.5 | 163-178 | 170.0.. Sey care | 21-30 26.0 19-23 PAVE) SRG ARO 5.49.6 7.4 5.1-8.0 5 | Bae: body; a dark postorbital bar usually present on each side of head. Variation—The male of the timber rat- tlesnake has a slightly lower ventral count average than the female, table 90. The juvenile differs from the adult most markedly in the presence of a terminal “‘but- ton” rather than a rattle and in having a lighter groundcolor. Tail rings are some- times visible on young snakes; the tails of subadults and adults are uniform black. On the basis of the number of scale rows at mid-body and average adult size, the rat- tlesnakes of extreme southwestern Illinois are referable to the Coastal Plain race, Cro- talus horridus atricaudatus, table 91. In ventral count averages and most details of pattern these snakes resemble the more northern specimens. Specimens from the Mississippi River counties of Illinois from Jackson County southward are therefore regarded as C. h. horridus X atricaudatus' 272 Table 91.—Geographic variation in Illinois Crotalus horridus. numbers of specimens. Ittrno1is NaturAL History SurvEY BULLETIN Vol. 28, Art. 1 Figures in parentheses are NuMBER OF SCALE Rows aT PERRY Mip-Bopy With 21 rows (per cent of speci- STIENS) cic ata eietecs aioe ae tetera eee 0 With 23 rows (per cent of speci- mens) Lae ee Aiea aheeateenas 33 With 24 rows (per cent of speci- METIS) ol aa hae ees wale eee 25 With 25 rows (per cent of speci- MENS) - ek ie ae eS eee 42 intergrades. This disposition of [Illinois specimens is in complete agreement with the range definition of the two races as pointed out by Gloyd (1940). Other variation in a sample of 30 timber rattlesnakes from various parts of Illinois is apparently individual. There is some evi- dence that snakes in one colony may differ from those in another colony in minor de- tails of pattern. This variation among colo- nies is not clear-cut and may be fortuitous. Anterior scale rows in the 30 snakes men- tioned above are as follows: 24 in 13 per cent of sample, 25 in 17 per cent, 26 in 50 per cent, and 27 in 20 per cent; posterior scale rows 18 in 3 per cent, 19 in 74 per cent, 20 in 20 per cent, and 21 in 3 per cent. Supralabials are highly variable; they range from 12 to 16 per side; 13 or 14 occur most frequently. Infralabials range from 13 to 18, {4 or 15 occuring most frequently. The number of body bands ranges from 20 to 26, averaging 23.6. A dark postorbital stripe on each side of the head is present in most snakes; it is dim in occasional specimens, particularly in those from northwestern and eastern Illinois. Light-centered lateral spots on anterior portion of body and black spots or dashes between the bands occur on nearly all the Illinois timber rattlers. The black phase, which occurs in more eastern populations of timber rattlesnakes, has not been encountered in this state, and only one of the Illinois specimens (INHS 1548 from Greene County) has the decidedly yellow groundcolor of eastern snakes. Most [llinois specimens of C. horridus are light gray, with sooty black bands. Habits.—This large rattlesnake is usu- ally found in areas where there are forested bluffs and rock outcrops. It is active day | ALEXANDER- Counties (12) Monror-PIKE CountiEs (8) Rock IsLanp- Jo Daviess Counties (5) Coes-JASPER Counties (4) 0 0 25 76 80 25 ibe? 0 25 12 20 25 and night. During the summer months, it hee Eee may be found in upland forests or even in — cultivated fields. Abandoned buildings, old sawmills, and brush piles are especially at-_ ‘idl ull il vi en rl LENG ami mei My (i sa i FE ll Paint Fig. 252.—Distribution of Crotalus horridus. Vertical hatching indicates the presumed range of the subspecies orridus in Illinois; cross- hatching, the area of intergradation between the subspecies horridus and atricaudatus; solid circles indicate localities represented by speci- — mens examined during this study; open circles, — localities represented by published records believed to be valid. The lower map depicts the total range of the species in the United States. November, 1961 tractive places, probably because of the small mammals to be found in such sites. In the fall the timber rattler congregates at den sites, which are usually rock bluffs with many deep cracks and fissures. The species is not aggressive, but in the wild it usually does not try to run. Once disturbed it coils quickly, sounds its rattle, and pre- pares to strike. The bite of the timber rat- tlesnake is serious, and deaths of human be- ings have been caused by Illinois snakes of this species. The food of this snake appar- ently consists almost exclusively of mammals and birds. Captive females of this species have given birth to broods of eight and nine young in late August. Illinois Distribution.—The timber rat- tlesnake still occurs in all the Mississippi River counties of Illinois in which the river bluffs have not been denuded of forest. The species is fairly common in a few areas along the Mississippi River where rock outcrops are extensive. It occurs in widely scattered colonies in Illinois south of the Shelbyville Moraine, fig. 252, but it has become so rare in this part of the state that the killing of a rattlesnake is usually recorded in the local SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS 243 newspapers. The timber rattler formerly occurred in bluffs up the Illinois River to at least La Salle County. J. F. Toedte of Chicago possesses a snapshot of a large C. horridus killed near Bailey Falls about 1924. However, the occurrence of the species in the Chicago area within historic times is highly questionable, despite the statement “rare in Cook County” made by Kennicott (1855). Although undocumented by specimens, published records for the following localities are believed valid and are indicated on the distribution map by hollow symbols: ADAMS County: Quincy (Gloyd 1940); Co Les County: 3 mi. E Charleston (Hankinson 1917) ; FuLttron County: (Necker 19395) ; Hancock County: Augusta (Necker 1939); Warsaw (Gloyd 1940); JEFFER- son County: Mount Vernon (H. Garman 1892) ; La SaLtE County: Bailey Falls (J. F. Toedte, personal communication); PE- orIA County: Peoria (H. Garman 1892) ; PuLaski County: (Necker 19395); RAN- DOLPH County: (Necker 19396); Sr. Craik County: Falling Springs (Hurter 1911); WapsasH County: (H. Garman 1892). LITERATURE CITED Adcock, Florence 1922. Ecological survey of the fauna of Lake Knox. Ill. State Acad. Sci. Trans. 15:186-99. Agassiz, Louis 1857. Contributions to the natural history of the United States of America. Little, Brown and Co., Boston. Vol. 1, 1-+52d pp.; vol. 2, 451-640 pp. Auffenberg, Walter 1955. A reconsideration of the racer, Coluber constrictor, in eastern United States. Tulane Studies Zool. 2(6):89-155. Baird, Spencer F. 1854a. Descriptions of new genera and species of North American frogs. Acad. Nat. Sci. Phila. Proc. 7:59-62. 1854. On the serpents of New York; with a notice of a species not hitherto included in the fauna of the state. Appendix G. N. Y. State Univ. Regents Ann. Rep. 7, 50:97—-124. 1858. Description of new genera and species of North American lizards in the Museum of the Smithsonian Institution. Acad. Nat. Sci. Phila. Proc. 1858:253-6. Baird, Spencer F., and C. Girard 1852. Jn Stansbury, Howard, 1852. 1853. Catalogue of North American reptiles in the Museum of the Smithsonian Institution. Part I.—Serpents. Smithsonian Institution, Washington. xvi-+ 172 pp. Baker, C. L. 1947. The species of Amphiumae. Tenn. Acad. Sci. Jour. 22(1) :9-21. 1948. The Amphiuma species of Florida. Tenn. Acad. Sci. Jour. 23(2):131-2. Baker, Frank Collins 1930. The use of animal life by the mound-building Indians of Illinois. Ill. State Acad. Sci. Trans. 22:41-64. 1936. Remains of animal life from the Kingston kitchen midden site near Peoria, Illinois. Ill. State Acad. Sci. Trans. 29(2) :243-6. Baur, G. 1893. Notes on the classification and taxonomy of the Testudinata. Am. Phil. Soc. Proc. 31:210-25. Bennett, Esther 1953. An Illinois record of the scarlet snake. Herpetologica 9:164. Bishop, Sherman C. 1941. ‘The salamanders of New York. N. Y. State Mus. Bul. 324. 365 pp. 1943. Handbook of salamanders. Comstock Publishing Co., Ithaca, N. Y. xiv + 555 pp. Bishop, Sherman C., and F. J. W. Schmidt 1931. The painted turtles of the genus Chrysemys. Field Mus. Nat. Hist. Zool. Ser. 18(4): 123-39. : Blanchard, Frank N. 1921. A revision of the king snakes: genus Lampropeltis. U. S. Natl. Mus. Bul. 114. vi + 260 pp. 1923a. The snakes of the genus Virginia. Mich. Acad. Sci., Arts, and Letters Papers 3:343-65. . 1923b. A new North American snake of the genus Natrix. Mich. Univ. Occas. Papers Mus. Zool. 140. 7 pp. 1924a. The forms of Carphophis. Mich. Acad. Sci., Arts, and Letters Papers 4:527—30. 1924b. A collection of amphibians and reptiles from southeastern Missouri and southern IIli- nois. Mich. Acad. Sci., Arts, and Letters Papers 4:533—41. 1942. The ring-necked snakes, genus Diadophis. Chicago Acad. Sci. Bul. 7(1) :5-144. Blanchard, Frank N., and Frieda Cobb Blanchard 1931. Size groups and their characteristics in the salamander Hemidactylium scutatum (Schlegel). Am. Nat. 65:149-64. Blatchley, W. S. 1899. Notes on the batrachians and reptiles of Vigo County, Indiana. II. Ind. Dept. Geol. and Nat. Resources Ann. Rep. 24:37-52. Blaufuss, A. H. 1943. The injection of snakes and lizards. Turtox News 21(3):56 Bocourt, Marie-Firmin 1870— Etudes sur les reptiles. Jz Dumeéril, Bocourt, and Mocquard. Recherches zoologiques 1909. pour servir a histoire de la faune de !’ Amérique Centrale et du Mexique. Mission Scientifique au Mexique et dans la Amérique Centrale, Paris. Part 3, sect. 1. xiv + 1,012 pp. [ 274 ] Cn November, 1961 SMITH: AMPHIBIANS AND REPTILES OF ILLINOIS P| Boulenger, G. A. 1889. Catalogue of the chelonians, rhynchocephalians, and crocodiles in the British Museum (Natural History). New ed. [British Museum, London.] x + 311 pp. 1893— Catalogue of the snakes in the British Museum (Natural History). [British Museum, 1894. London.] Vol. 1, xiii + 448 pp.; vol. 2, xi + 382 pp. 1920. A monograph of the American frogs of the genus Rana. Am. Acad. Arts and Sci. Proc. 55(9) :413-80. Bragg, Arthur N. : 1954. Bufo terrestris charlesmithi, a new subspecies from Oklahoma. Wasmann Jour. Biol. 12 (2) :245-54. Breckenridge, W. J. 1944. Reptiles and amphibians of Minnesota. University of Minnesota Press, Minneapolis. xiii + 202 pp. Brendel, Fred 1857. In Gerhard, Fred, 1857. Brimley, C. S. 1939— The amphibians and reptiles of North Carolina. Carolina Tips 2(1-7), 3(1-7), 1943. 4(1-7), 5(1-6), 6(1-5): various pages. [Title varies. | Brown, Arthur Erwin 1901. A review of the genera and species of American snakes north of Mexico. Acad. Nat. Sci. Phila. Proc. 53:10-110. Brown, Bryce C. 1950. An annotated check list of the reptiles and amphibians of Texas. Baylor University Press, Waco. xii + 257 + [2] pp. Burger, W. Leslie, Philip W. Smith, and Hobart M. Smith 1949. Notable records of reptiles and amphibians in Oklahoma, Arkansas, and Texas. Tenn. Acad. Sci. Jour. 24(2) :130—-4. Burt, Charles E. 1928. A new amphibian record from Kansas, Hyla phaerocrypta (Cope). Science 67 (1747): 630-1. 1931. A study of the teiid lizards of the genus Cnemidophorus, with special reference to their phylogenetic relationships. U. S. Natl. Mus. Bul. 154. viii + 286 pp. 1935. Further records of the ecology and distribution of amphibians and reptiles in the Mid- dle West. Am. Midland Nat. 16(3):311-36. Burt, Charles E., and May Danheim Burt 1929. ... 20055 S080. fe ed Ds eles 3ifa Changes in Stream Habitats. ...:. 05... Fig. 4.—Distribution of the 1959 collecting stations (solid circles) in Champaign County. Open symbols represent collecting sites, not revisited in 1959, of the two prior surveys: inverted triangles the Forbes & Richardson survey and circles the Thompson & Hunt survey. 306 I:uinoris NaruraAt History Survey BULLETIN visits to certain stations in an attempt to obtain unusual species that had not been taken on our initial visits, but that had been recorded at the stations by Thompson & Hunt. The streams sampled and the number of collecting stations on each stream, including stations for cruising and supplemental sampling, were as follows: Salt Fork 55, Sangamon 39, Kaskaskia 22, Embarrass 20, Middle Fork 11, and Lit- tle Vermilion 5. The distribution of these 152 localities is depicted in fig. 4. Sources of Additional Information. —Several Champaign County anglers pro- vided reliable observations. The records they provided were evaluated separately from those of our own collections; their degree of reliability is fully indicated in the Annotated List of Fishes. Two opera- tors of commercial fee-fishing lakes pro- vided information that was used. DESCRIPTION OF COUNTY In about a century, much of Champaign County has been converted from marsh- land infested with deer flies to well- drained, fertile farmland. It has been in- tensively cultivated for several decades, and its streams have been modified by dredging, tiling, silting, and other in- fluences that accompany agricultural prac- tices. The human population has mush- roomed in recent years, and some areas have become industrialized, providing an opportunity to observe the effects of sew- age and industrial wastes on streams and stream life. Located in east-central Illinois, Cham- paign County, fig. 5, is 36 miles from north to south and 27 miles from east to west. It occupies 988 square miles (632,- 415 acres) of flat to slightly rolling land; the present relief resulted from relatively recent glaciation and from _ postglacial stream erosion. The altitude ranges from 630 to 860 feet above sea level and aver- ages about 710 feet. Although essentially a flat plain, it is somewhat higher than surrounding counties, and four major stream systems arise within the county. Two other stream systems originate a short distance north of the county limits. The county has been glaciated twice, but the effects of the more recent Wis- consin stage (about 18,000 years ago) ob- scure those of the much older Illinoian Vol. 28, Art. 2 stage. The series of end moraines, which rise from 50 to 100 feet above the inter- morainal basins, usually form boundaries between drainage systems. The entire MISSOURI RIVER— SSOUR RS % ° Ix ; = - ca “S$ BS 7A) 2 2 ps) ov? —' ape Ter Fig. 5.—Location of Champaign County and its streams in relation to the state and major drainage systems. The dotted line indicates the boundary of a particularly fertile area, at one time mostly prairfe marsh. county is overlaid with a mantle of Wis- consin glacial till, which is covered with a layer of loess of varying thicknesses up to 8 feet, except where the loess has been” eroded away. The county contains no rock outcrops. Soils The soils reflect the soil parent material the drainage, and the vegetational history of the area. Dark upland prairie soils make up about 92 per cent of the area; yellow-gray silt loams, the upland timbe soils, make up about 5 per cent; bottom: land or terrace soils constitute the sma remainder (Hopkins et al. 1918:6). A recent arrangement of the soil types of Champaign County is presented in the March, 1963 following paragraph (Fehrenbacher 1963 and personal communication from Dr. Russell T. Odell, Professor of Soil Pedol- ogy, University of Illinois). The dark upland prairie soils can be placed in four general groups. A group of silty loess prairie soils (mainly Drummer, Flanagan, and Catlin soil types) covers about 40 per cent of Champaign County. These soils are loam till covered with 3 to 5 feet of loess. Properly managed, they are the most productive in the county, averaging about 95 bushels of corn per acre per year. A second group of prairie soils, mainly Drummer, Brenton, and Proctor soil types, consists of silty outwash soils with greater subsurface flow and higher permeability than the first group men- tioned. They cover about 26 per cent of the county and also are very productive. This group of soils is associated with the former marshes. A third group, made up of medium-textured prairie soils, occurs in rolling areas mostly along the Cham- paign Moraine and covers about 10 per cent of the county. A fourth group, com- posed of fine-textured prairie soils of silty clay loam and silty till, covers a large area in the northeastern part of the county and scattered areas in the northwestern part, a total of 16 per cent of the county. This group is somewhat less productive than the other prairie soils. The small remaining group, consisting of nonprairie soils, is generally associated with the river valleys and constitutes the least productive soils in the county. Weather Champaign County has a _ temperate continental-type climate without the mod- ifying influences of a large body of water. In most years, temperature extremes range from well below 0 degrees to slightly over 100 degrees F. The annual mean temperature is 52 degrees F. (Changnon 1959:46). Comparison of monthly aver- age temperatures over a 5/-year period during which weather records have been kept at Urbana reveals great fluctuation but no significant trend. August, the month of our most intensive collecting in 1959, was considerably warmer than the August average. The county receives an average of about 36 inches of precipitation per year. Larimore & SmiItTH: FisHES or CHAMPAIGN CoUNTY 307 Although the annual averages for 1929- 1958 were similar to those for the preceding 1903-1928 period, judged by data graphically presented by Changnon (1959:11), the 5-year period immediately preceding Thompson & Hunt’s study was exceptionally wet, and the years 1930, 1953, 1954, and 1956 were exceptionally dry, the annual rainfall being less than 30 inches. The years 1940 and 1959 re- ceived subnormal amounts of precipitation and were marked by unusually dry sum- mers. The summer months of 1959 were extremely dry and resulted in low water levels during the time of our intensive field work. Agricultural Practices Champaign County is one of the most productive grain areas in the world. Dur- ing more than a century of farming, this county has undergone great changes in landscape, in farming methods, and in crops. These changes include the draining of the wet prairies and marshes to convert them to productive farmland, the use of large machinery, and the widespread use of commercial fertilizers and new and improved plant varieties. The farming of the first settlers in this county was largely restricted to raising cattle and small crops on the high areas and along the stream courses where drain- age was naturally good. Lands that were dry enough for cultivation were turned by oxen. During the last quarter of the nineteenth century, ditches were dug and tiles laid to drain the wet prairie fields. By 1900, the farms averaged between 80 and 100 acres in size. With the development of large farm machinery—heavy tractors, combines, seeders, and corn pickers — many farms were merged to form larger ones. Cur- rently, the average Champaign County farm is about 200 acres. Within the past 30 years a trend toward less diversifica- tion among farm crops has appeared ; corn and soybeans have become the two lead- ing crops. During the 1940’s, the widespread use of commercial fertilizers brought about a general increase in average yield. Hybrid plants and improved varieties added to yields. Recently, liquid nitrogen as a fer- tilizer has further increased production. 308 At the time of settlement of Cham- paign County, very little soil eroded from the prairie and timber areas, but intensive farming made erosion a serious, constant threat even in the nearly flat or gently sloping lands of Champaign County. As the native vegetation was removed and the soil directly exposed to rain and wind, the soil became compact and less absorbent, causing more rapid runoff, accompanied by the loss of rich topsoil. The inadequacy of soil conservation practices had adverse effects upon the streams and contributed to more frequent floods followed by seri- ously low water levels. The effects of soil erosion and the need for intensive con- servation methods are not fully appreci- ated by many Champaign County farm- ers. Few grainfields are farmed on the contour, strip cropping is rare, and grass waterways are maintained in relatively few of the cultivated fields. Farm animals are permitted to graze the stream banks and thereby contribute to serious erosion and siltation. Population, Urban, and Industrial Developments During the first half of the twentieth century, striking changes in land use in Champaign County were brought on by the increasing human population. In 1900, the census reported 47,622 people residing in the county; in 1930, 64,273; in 1960, 132,436. The trend has been toward ur- banization; in 1900, 31.1 per cent of the population lived in urban areas and, in 1960, 75.6 per cent. Although there are about 26 cities and villages in the county, only Champaign-Urbana, Rantoul, and a few others have increased in population. Some of the small villages in the county have remained static in population or have even declined. The changes in size of urban areas is illustrated by fig. 6, which shows the village limits of the 1870’s in red and the recent limits in black. A considerable acreage of farmland has been usurped by urban and surburban de- velopment. The total number of acres in cultivation was roughly the same between 1900 and 1928 and was considerably greater than it is today. Since 1928, cleared land, particularly that marginal to cities and villages, has been pressed into nonagricultural uses. Many areas Ittinois Natura History Survey BULLETIN Vol. 28, Art. 2 that were once farmed now are covered by modern schools, grain storage units, and industrial developments; other large land areas now are occupied by Chanute Air Force Base and the campus of the Uni- versity of Illinois. These lands are per- manently out of production of farm crops. The vast network of roads, including sev- eral major highways that transect the county, occupies a large and ever-increas- ing area. A highly developed road system has made Champaign County ideally suited for the study reported here because roads — are laid out, orderly and regularly, paral-_ lel to each other at mile or half-mile in-— tervals throughout the county. All streams could be sampled conveniently at almost any point, and electrofishing and other heavy collecting gear could be transported — by automobile almost to the water’s edge. Stream Drainages and Courses The stream drainages of Champaign County can be summarized as follows. Six rivers have headwater channels in the county, four of which (Salt Fork, Em-— barrass, Kaskaskia, and Little Vermilion i actually originate ‘within the county. All f of the drainages are separated by moraines, — except the Sangamon and Salt Fork; dur-_ ing times of flood, headwaters of the San-_ gamon and Salt Fork may connect, al- though connection occurs much less free quently now than formerly. The total drainage area (in square miles) of each of these rivers within the county is as fol- lows: Sangamon 277, Salt Fork 346, Mid- dle Fork 69, Embarrass 138, Kaskaskia) 168, and Little Vermilion 40: a re smiles streams flow out of the county, but each joins one of the six larger rivers The relationships of the streams to the larger rivers are shown in fig. 5. | The total drainage area (in square miles) of the main course of each of these rivers at the point the river leaves Cham= paign County is as follows: Sangamon — 388, Salt Fork 307, Middle Fork 241 Embarrass 106, Kaskaskia 98, and Little Vermilion 28. These figures include up: per reaches of those rivers that rise out side the county. a Water Discharge.— Annual average discharge records for two gaging sta March, 1963 Larimore & SmitH: FisHEs or CHAMPAIGN CouNTY 309 tions near the periphery and for three stations well within the county are avail- able, table 1. The records show the size of the streams at these stations and indi- cate the amount of water drained from the different watersheds. Calculated from fig- ures in table 1, the annual average dis- charge of water per acre in the period ending in 1957 was 0.7 cubic feet per second (c.f.s.) for the Sangamon, Salt Fork, and West Branch; 0.6 c.f.s. for the Kaskaskia; and 1.0 c.f.s. for the Bone- Fig. 6.—Distribution of towns and water areas in Champaign County in the 1870's (in red ) | and 1950’s (in black). Drawn from map in Atlas of the State of Illinois (Anon. 1876) and U. S. Geological Survey Quadrangles (editions 1950-1957). 310 Ittino1is Natura History SurRvEY BULLETIN Vol. 28, Art. 2 Table 1—Water discharge records taken at five gaging stations in Champaign County (U. S. Geological Survey, 1953-1960). LOcATION STREAM OF STATION Sanparmnone =. ee ee SEE, Near Mahomet Sale Meneses eee a a eA Near Homer Kaskaskia. a Near Bondville Boneyard_. Near Urbana West Branch Near Urbana ANNUAL WATERSHED, Avan ice YEARS een Disc pat Soaiee rs (C.F.S.) 356.0 249.00 1948-1957 344.0 243.00 1944-1957 23 8.05 1949-1957 4.6 4.62 1948-1957 71.4 50.40 1936-1957 yard. The lowest discharge per acre was for the Kaskaskia drainage, which is en- tirely farmland, and the highest discharge was for the Boneyard drainage, which is almost entirely urban, lying within Cham- paign-Urbana. The records on the Sangamon River taken near Monticello are of special value in that they show changes in stream dis- charge over a long period. Although the gaging station is about 10 miles outside Champaign County, it records the runoff from one-quarter of the county. Records are nearly complete back to 1908. They show that annual average discharge fell below 200 c.f.s. only once during the two decades before the Thompson & Hunt study of 1928, but fell below this level eight times in the three decades since. The low discharges in recent years indicate the reduced water-holding capacity of soils of the watershed. The river now re- sponds quickly to precipitation or drought, whereas it had a more nearly constant flow before 1928, The minimum discharge of a stream has great significance to fish distribution. Before the Thompson & Hunt study, there was no record of the Sangamon River discharge dropping as low as 1.0 c.f.s. but it reached 1.0 c.f.s. or lower five times in the three following decades. As might be expected, there is a high correla- tion between precipitation and water dis- charge of streams in an area. There is, of course, a variable time lag between pre- cipitation and discharge. Draining and Dredging.— Because of the original marshy character of Cham- paign County, much draining, dredging, and straightening of waterways has been necessary to prepare the land for agri- culture. The Illinois Farm Drainage Act of 1879 encouraged the formation of drain-— age districts and enabled farmers to par-— ticipate in the installation of drainage systems to serve large areas. Drainage proceeded rapidly during the following two decades, and, by the turn of the cen-— tury, when Forbes & Richardson made the first extensive fish collections in the area, 36 per cent of the county’s 632,415 acres had drainage improvements, table 2. The number of acres in drainage dis- tricts almost doubled between 1900 and 1910, with 190,205 additional acres (30 per cent of the county) receiving drain-— age improvements. In the decades since 1910, the amount of new land drained has declined, table 2. ‘The acreage of land” placed in drainage districts in the three decades between 1930 and 1960 amounted Table 2—Acres of land in Champaign County placed i in drainage districts during eac period since about 1880 and the per cent of the county (632,415 total acres) with drainag improvements by the end of each decade. In formation from the Federal Land Bank of St. Louis and Champaign County records. Per CENT OF ACRES PLACED | County WITH PERIOD IN DRAINAGE DRAINAGE DISTRICTS IMPROVEMENTS Pre—-1891 162,298 26 1891-1900 66,951 36 1901-1910 190,205 66 1911-1920 23,524 70 1921-1930* 24,174* 74* 1931-1940 22,838 eh 1941-1950 16,064 80 1951-1960 14,046 82 *In 1921-1930, 3,060 previously unrecorded acres th had received drainage improvements prior to 1927 (da unknown) were included in the acreage total for th period, column two, and taken into account in the p centage figures for this and later periods, column three. March, 1963 to only 8 per cent of the area of the county. When Thompson & Hunt made their collections in 1928, 74 per cent of the county was in drainage districts. By 1959, 82 per cent of the county (520,100 acres) had received drainage improvements. Of the 18 per cent of the county remaining, probably a considerable proportion has adequate natural drainage or is in non- agricultural use. Future drainage probably will consist mostly of maintenance and improvement of existing systems. Dredging to increase the water-carrying capacity of existing streams, or to create ditches in the undrained marshy areas where none existed, eliminated areas of standing water and created new channels. Recanalization of natural streams re- sulted in much straightening, in the erec- tion of high earthen banks along the sides, in producing greater uniformity of the stream environments, and in drastically altering local habitats, fig. 11. Subsurface drain tiles reduced areas of standing water and in some places resulted in burying what had been surface drain- age courses. As a result, many small, in- termittent streams have been replaced by field tiles or by wide, carefully graded grass waterways. Draining and dredging, which have re- duced the water storage capacity of the watershed, have contributed to higher flood levels and lower drought levels in the streams. These practices have lowered the water table and affected the perma- nency of many small streams. Since the early 1870’s, work has been directed to- ward improving the drainage in Cham- paign County; in the future this objective may need considerable modification as de- mands for water supplies increase and ef- forts are made to hold water to meet these demands. Some stream courses have been altered. Slight changes in drainage boundaries can be seen on the upper reaches of Hayes Creek, Copper Slough, Camp Creek, the Salt Fork above Rantoul, and the head- waters of the Little Vermilion system. ‘Two stations where Thompson & Hunt seined, one in a small tributary of the East Branch of the Salt Fork about 3 miles southeast of Rantoul, and one in a tributary of Hayes Creek on the Cham- LarimorE & SMITH: FISHES oF CHAMPAIGN CoUNTY 311 paign-Douglas county line, were no longer extant in 1959. They had been replaced by grass waterways. Near St. Joseph, the Salt Fork had been straightened, leaving a large oxbow at the west edge of town. Numerous small streams visited in 1928 by Thompson & Hunt were completely dry in the summer of 1959, due probably to the dry summer rather than to modi- fications by man or to long-term natural changes. Some stream changes, including new channels and new meanders, were nat- ural. Such changes as occurred in the county between the mid-1870’s (shown in red) and the mid-1950’s (shown in black) can be detected in fig 6. STREAM HABITATS Most Champaign County streams origi- nate at drain tiles, fiz. 7, on the slopes of moraines, or in flat, marshy areas. They flow through straight, usually man-made ditches in rich farmland and move on into less disturbed channels as they be- come larger and their valleys widen. Cer- tain general ecological characteristics are common to these streams and can be used to distinguish and describe several stream habitats. General Ecological Characteristics In Champaign County, the relatively flat topography, the lack of rock outcrops, the similarity of soil materials, and the intensive land-use practices produce an unusual amount of uniformity in the stream environment. The stream gradient is generally low, usually between 3 and 4 feet of fall per mile. Only on the slopes of moraines and in a few short stretches does it exceed 6 feet per mile. The flow is generally mod- erate to sluggish during normal water stages. Rifles are gentle and pools are rather shallow. There are long stretches of very uniform depth and flow. Water levels fluctuate rapidly and dras- tically. Flooding occurs with some reg- ularity, particularly during the spring and early summer. At normal water stages, streams have levels well within their steep-sided banks. During flood stages, the water levels may rise 10 to 15 feet and temporarily become torrents that erode away stream banks. Within the county, 312 the Sangamon, Salt Fork, Middle Fork, and to a lesser degree the Embarrass rivers have narrow floodplains, which may be completely inundated during floods. Se- vere dry periods occur nearly every year, usually during August and September. The flow may decrease drastically or even cease. The small headwater tributaries suffer most regularly and severely from dry weather conditions. Water temperatures in small, shallow, . stagnant pools may approach 100 degrees F. during the summer and 32 degrees in the winter. There are no large springs to moderate water temperatures. The lack of shading bank vegetation along shallow areas allows extreme daily fluctuations of temperature, which, in summer, may change as much as 20 degrees F. between the cool morning hours and the hot mid- afternoon. In winter, temperatures may drop sufficiently to freeze the water to the stream bottom in shallow areas. Be- cause fish generally concentrate in deep pools, they are seldom caught in the ice. The distribution of bottom materials, formed from the basic glacial till, is di- Ittinois NarurAL History SURVEY BULLETIN Vol. 28, Art. 2 rectly related to the velocity of the water. Through selective sorting of the basic ma- terials, rubble and gravel (the heaviest materials) pile up in riffle areas, sand in areas of moderate current, and the finer particles of silt and clay drop out only in the quiet waters of the deep pools. Turbidity is generally high, becoming low only during the cold months, when the activity of fish is reduced so much that it does not roil silt on the bottom and when streams are said to be “‘winter clear.” During the field work for the present study, turbidity ranged between 15 and 150 parts per million (p.p.m.). The chemistry of stream water, bas- ically related to the mineral composition of the watershed, may be strongly in- fluenced by domestic and industrial pol- lution, table 3. Water in the lower Em- barrass, Kaskaskia, Spoon, and Sangamon rivers, which are relatively unpolluted, is low in ammonium, phosphate, and nitrate, in comparison with water from the pol- luted areas in the Salt Fork River. Hard- ness (as calcium carbonate content) ranges from 264 to 436 p.p.m. The pH is slightly Table 3.—Partial chemical analysis of water collected from seven stream locations in Champaign County on December 29, 1960. The streams were mostly ice covered and at normal — water level. Temperatures of samples ranged from 32 to 34 degrees F. The water had no measurable color or odor. Turbidity was less than 24 p.p.m. Analysis was made by the Illinois Water Survey. All figures are for p.p.m. = rea) ae i a =) 5 =O | 2O AN & Z 2 = 8 2 29) 82) 54) ae STATION S < a. es < < 20 | BO | 26 en 2) ¢€) 8) 28) 8 | & ) 8.) 32) ee <_|/2js)#8 |6)28 | & |) ¢2)n° | ease Embarrass North of Villa Groview ee 2 os 0.2 2.8 0.1 13 111.7 8.7 284 392 477 0.0 Sangamon Northeast of Mahomet 2.) 0.3 5.8 0.0 32 | 115.0 4.5 304 428 555 0.1 Kaskaskia West of Rarkyillew. = sec 27 tr. 6.5 0.5 7 19.1) 11.4 308 264 370 0.1 Spoon River North of St: Josepha = 0.5 2.4 0.1 13 | 152.6} 10.4 | 320 | 436 555 0.0 East Branch North of St) joseph. sos" 74 18.2 13.1 255 85.6 | 14.0 292 372 850 0.7 West Branch East of JO jit|o feta: tnes swath lemons 7.5 14.9 47.4 100 | 193.2} 14.4 360 376 842 1.2 Salt Fork Northwest of lo mer se 2 re 4.8 15.9 PUD Pe 116 107.2} 15.0 312 336 705 0.9 Bi eae a, OREO March, 1963 above neutral, most of the readings rang- ing from 7.2 to 7.8. The amount of dis- solved oxygen varies from supersaturation in well-aerated riffle areas to less than | p-p-m. in highly polluted waters and in stagnant pools when the stream flow is discontinuous. Much of the natural aquatic vegetation in Champaign County streams may have been eliminated early in this century through dredging, pollution, and other man-induced alterations. The remaining vegetation is limited in distribution by the generally high turbidity of the streams. Baker (1922) illustrated many of the stream habitats along the Salt Fork as they appeared in 1919 and 1920. Except for a large patch (which no _ longer exists) of yellow water lillies, Nuphar advena, northeast of Sidney, the vegeta- tion seen in his photographs is similar to that found at present. Moreover, his de- scription of the aquatic vegetation in- cludes essentially the same species that now occur in the area. Thompson & Hunt listed the common coarse aquatic plants that they observed. Their list includes most of the present vegetation. They listed four species of Potamogeton that we did not find as- sociated with the flowing waters of the county ; however, we observed another spe- cies of Potamogeton, believed to be P. foliosus Rafinesque, in a number of streams and found it to be quite common in the upper reaches of Lone Tree Creek near Foosland. The field notes of Thomp- son & Hunt and our observations indicate that aquatic vegetation was more exten- sive in 1928 than it is today. Dr. Robert A. Evers, of the Section of Applied Botany and Plant Pathology of the Natural History Survey, examined plants in several collections we made dur- ing the present study. His identifications add the following species to the list pre- sented by Thompson & Hunt: Equisetum arvense Linnaeus Spartina pectinata Link Carex cristatella Britton Salix interior Rowlee Rumex altissimus Wood Rorippa islandica (Oeder) Borbas Lysimachia nummutlaria Linnaeus Asclepias incarnata Linnaeus Phyla lanceolata (Michaux) Greene Larimore & SmITH: FISHES OF CHAMPAIGN COUNTY 313 Lycopus americanus Muhlenberg Eupatorium perfoliatum Linnaeus Hibiscus militaris Cavanilles These plants are not true aquatics but are characteristically associated with the banks and mud flats along most of the streams. A few true aquatics deserve spe- cial comment. Potamogeton foliosus has already been mentioned as quite common in part of Lone Tree Creek. Elodea canadensis Michaux occurs in_ large patches in the polluted West Branch be- tween Urbana and St. Joseph. Dianthera americana Linnaeus is abundant on the rifles and along the shores of many streams, especially in the Middle Fork. Chara sp. was taken near a seepage spot on a tributary of the Spoon River near Flatville. The vegetation we observed in our study included grasses, sedges, ragweeds, milkweeds, docks, and several composites along the small streams as they passed through flat and open farmlands. In some of the reaches of these streams, willows and scrubby growths of a few other de- ciduous trees overhung the water. Tall de- ciduous trees lined the banks of most of the large streams. Especially common were silver maple, American elm, cottonwood, sycamore, and willows. In open areas, where the sunshine reached the water, grew buttonbush, rose mallow, water wil- low, and a few other plants. Habitat Types Although the general ecological char- acteristics of the streams of Champaign County are rather uniform, each stream contains several distinct habitats. The habitats are determined largely by stream size, stream topography and gradient, soil materials comprising the bottom, and hu- man modification of the stream and its drainage basin. Thompson & Hunt (1930:34-9) clas- sified stream habitats according to size of area drained, permanency, depth, width, current, type of substrate, amount of veg- etation and debris, turbidity, and faunal composition. They recognized vernal rivu- lets; kettle holes at mouths of tile drains; oxbow ponds along small streams; per- manent headwater streams; stretches of shallow, sluggish water; gravelly and sandy rifles and stretches; rocky rapids 314 Ittinois NATuRAL History SURVEY BULLETIN 4 i < Vol. 28, Art. 2 Table 4.—Champaign County stream habitats, the extent of their occurrence, and their physical characteristics. DRAINAGE | AVERAGE | MAXIMUM MILES IN AREA GRADIENT DEPTH HABITAT COUNTY (SQUARE | (FEET PER | (RANGE IN CURRENT MILEs) MILE) INCHES) Rivulet and small creek 189 10 7 1-10 Variable Large creek _____ 176 10-200 PR) Rifle Sand and hie eravel ss be Sr oe ee ea ae 1-12 Swift Gravel atid DOU der ee ee ee eee 1-12 Swift Pool 4 Shallow bernie Ter OE LU ath «Oe 4-24 Moderate ~ Deepa a sey ee Se SN, a a a ee Soe 24-48 Sluggish Sine DEV es eee ee 58 200-400 2 Se wee Riffle A Sandvand pravel 2 = =o Bi Ei ae eee i ge a 3-18 Swift ts Boulder and rubble ae 3-18 Swift Pool Shall yy ees wee een POD oe Sets eee oe Bees 18-36 Moderate | bY, Seana a OREM ae sa ES. PEN one eA atin Rees 36-96 Sluggish and rifles; moderately deep, smoothly flowing stretches; and long, deep pools. They described each habitat and listed characteristic species of fishes. We prefer a classification based on the same ecological characteristics but having divisions with more easily definable limits, table 4. Rivulets and Small Creeks.— Our rivulets and small creeks include the ver- nal rivulets of Thompson & Hunt and also intermittent streams of slightly greater size. They arise as small open gullies coming off the face of moraine ~ slopes, as seeps in grass waterways, or as discharges at field tiles, fig. 7, draining — flat marshy areas. The type that originates — at a field tile may have an unusual be- — ginning because of the large, and some-_ times surprisingly deep, hole that is — scoured out at the base of the tile. In © many cases, the pool contains a large con- — centration of fish. 5 Most rivulets and small creeks in — Champaign County have been modified — by dredging and straightening of the chan- — ‘We Oe Fig. 7—Drain tile mouth and pool on the East Branch of the Salt Fork of the Vermilion River. A tile mouth is Champaign County’s analogue of a spring. March, 1963 nel. They consist of a long open ditch, flowing smoothly over a substrate of clay, silt, or loam. They lack aquatic vegeta- tion but are bordered by grasses, herbs, and shrubs. Although they include oc- casional water pockets that could be termed pools, and occasional shallow areas where there is an accumulation of sand and gravel suggesting rifles, their distri- bution of fishes is relatively uniform throughout. These long open ditches may partially dry up if water flow ceases dur- ing the summer months. Their small size, instability of flow, and lack of shade pro- duce a highly unstable aquatic environ- ment. Large Creeks.— The streams we classify as large creeks are formed by the confluence of the rivulets and small creeks. The water contributed by the network of tributaries is of such volume that flow is continuous throughout most years, al- though the actual volume may fluctuate drastically from wet to dry _ seasons. Typically, the large creeks consist of al- ternating pools, shallow stretches, and rif- fles (frontispiece). They contain a greater Lartmore & SmitTH: FISHES oF CHAMPAIGN COUNTY 315 variety of habitats than do rivulets and small creeks. The frequency of occurrence of rifles depends upon the distribution of glacial drift materials, the extent of dredging, and the stream gradient. Some of the large creeks in Champaign County have been dredged ; they now have straight rather than meandering courses, a mo- notonous sameness of environment, and nearly uniform depth, fig. 8. In the large creeks, rifles over sand and fine gravel are usually without aquat- ic vegetation; those over gravel and small boulders have some attached algae. Some pools are shallow and have a moderate flow over clay, sand, and silt; they have a variety of aquatic vegetation. Other pools are quiet and deep, having been formed by obstructions or unusual erosion of the bottom materials; they have ac- cumulations of silt and only marginal veg- etation. Long, shallow pools make up large proportions of most of the Cham- paign County streams we have classified as large creeks, fig. 11. Small Rivers.— The largest streams in the county, hardly larger than creeks Fig. 8.—The Kaskaskia River southwest of Parkville. This stream, dredged from time to | time, illustrates one of the large creek habitats found in Champaign County. Modification of | this creek resulted in an unusual amount of sand in the stream bed. 316 ILLiNois NaTturAL History SuRvVEY BULLETIN Vol. 28, Art. 2 : MS ee Fig. 9.—Upper picture: a shallow pool in the Sangamon River near Fisher. Habitats such — as this contain several species of suckers, basses, and sunfishes, and many species of small fishes. — Lower picture: a deep pool in the Salt Fork near Homer. Habitats such as this contain carp, — catfish, shad, and relatively few species of small fishes. a! Be ae March, 1963 by some standards, we have classed as small rivers, figs. 2 and 3. They include the lower Sangamon, the lower Salt Fork, and the Middle Fork. They are perma- nent streams that have less extreme and less sudden fluctuations in water level and temperature than creeks. Their flood- plains and banks are generally shaded by large trees, fig. 9. Like large creeks, the small rivers contain both riffle and pool habitats, table 4. Riffles of small rivers differ from those of creeks in their greater volume of flow and their greater proportion of large- sized bottom materials. Because of the low gradient of the small rivers, the rifles in these streams are relatively fewer in num- ber and occupy a smaller proportion of the total water area than do those in creeks. Sand and fine gravel riffles with little aquatic vegetation occur in small rivers as well as creeks; because sand and fine gravel occur also in many boulder and rubble rifles that have some aquatic veg- etation, the two types of rifles are less clearly defined in rivers than in creeks. Pools in small rivers are either shallow and have moderate water flow, or deep and have sluggish current, fig. 9. Their characteristics are similar to those of large creeks, but the pools are deeper and have more overhanging vegetation and greater silt deposits. In certain parts of the lower Salt Fork and lower Sangamon, occasional pools are quite deep and have very slug- gish water movements. Other Aquatic Habitats. — Other Champaign County aquatic habitats that do not fit into the above classification are nonstream habitats, such as farm ponds, artificial lakes, and oxbows. No natural lakes and no permanent swamps and marshes remain in the county. Ponds and artificial lakes are of little interest in the present study inasmuch as they have been stocked, and they are of concern only if the fishes they contain spill over into the streams. Oxbows have characteristic la- custrine populations. “The component spe- cies obviously were derived from the streams with which the oxbows were once associated. Changes in Stream Habitats The environment of a stream is sensi- tive te almost any activity within the Larimore & SmitH: FISHES OF CHAMPAIGN CouUNTY 317 watershed. It is influenced by the human population, agriculture, and industry as outlined previously in this paper. For the 30-year period between the studies of Forbes & Richardson and those of Thompson & Hunt, specific measure- ments or observations of the stream en- vironment were limited to some studies of stream-flow measurements and drain- ing activities. From these studies and the information on the general development of the county, we know that many water habitats were actually eliminated and that draining and dredging resulted in in- creased fluctuation of water levels, in- creased turbidity, and a reduction in aquat- ic vegetation. We know that channel straightening, with the elimination of meanders, actually shortened stream courses in many areas and consequently increased the stream gradient. The re- placement of stagnant-water marshes by underground drains that discharge waters that are relatively cool in summer and warm in winter may have reduced seasonal fluctuations of stream temperatures. Between the investigations of Thomp- son & Hunt in 1928 and the present time, we have specific information on certain changes that have occurred. Thompson & Hunt’s original field notes provide an un- usual opportunity for evaluating various changes in habitats at identical, or nearly identical, collecting sites, figs. 10 and 11. Habitat differences can be seen at specific sites described by Thompson & Hunt and then examined 30 years later during the 1959 investigation. These differences have been evaluated and summarized in table 5. The principal changes noted have to do with dimensions, particularly in average depth and average width of the pools where collections were made. The field work of the 1928 survey was carried on “from early spring to late autumn” (Thompson & Hunt 1930:14); most of our collections were concentrated in the dry months of late summer. The entire summer of 1959 was considerably drier than that of 1928. Despite differences in the time of field work and in the amount of precipitation in 1928 and 1959, the two censuses disclosed that measurable changes had taken place in the Champaign County drainage systems in the years be- tween the censuses, table 5. Vol. 28, Art, 2 Fig. 10—The Sangamon River near Mahomet in the autumn of 1928 (above) and the au- tumn of 1962 (below). The habitats at this site have remained relatively unchanged. March, 1963 Larimore & SmiTH: FisHEes or CHAMPAIGN CoUNTY 319 Fig. 11—The Kaskaskia River near Bondville in the autumn of 1928 (above), some years after it had been dredged, and in the autumn of 1962 (below) Kaskaskia is classed as a large creek. , after another dredging. Here the Ittrnors Natura History Survey BULLETIN Vol. 28, Art. 2 7 f the habitat data are the percentage of stations that (+) in each of these character- Only those stations are included for which most o s Champaign County drainages as indicated by and the percentage that showed an increase 928 and the 1959 study. ained the same (0), n stream habitat characteristics of variou Table 5—Changes i showed a decrease (—), the percentage that rem istics between the Thompson & Hunt study in 1 available. “ et ee a a & wooneo 5 ~ one 2) -_ _ > Eero e Z +t+nooSD oot at 'A2e | HOte wnoned he mNAWwS O=zA6 mm | ouwuouno > ! Non al Zz onono ek Piet ee = ree wNoONSO PSs Acoowncn jo] Oo <8 +t+aocoo > aan Noone wm mn oO 8 aonooneo A tMman~N o+tooo ~ N+tonNno mmr nC (2) Z ononeo a tO ONO Dn oocooo =) 3) > < 6 wotone = en SO on + OO 5 aonoceo = Atowotna ecoono Noel men aocooceo -_ m a onowno g +tANMm WMO a) Non OM oO wmmoen + Sa a4 Ze Ss et 2h Z i ' ra o : < H Zz 1 = f = ! = Sangamon __ Kaskaskia__._._____- Embarrass... Salt Fork Middle Fork All of the Champaign County drainage systems showed a decided trend toward a decrease in depth and an increase in width, table 5. All of them showed a decrease in gravel and an increase in sand. All but — the Kaskaskia River showed an increase in silt, which had covered the gravel or sand present in 1928. In the Kaskaskia, however, sand deposits had covered over both the gravel and silt formerly re- corded, fig. 8. A general decrease was — evident in the occurrence of aquatic veg- — etation; an increase had occurred, except — along the Sangamon and Kaskaskia rivers, in the amount of overhanging vegetation. — Only in the Kaskaskia was there a strik- ing change in water velocity, an increase caused by recent dredging and straighten- ing of the river and perhaps by the in- troduction of large volumes of well water — in its upper reaches. Except for the gen- — eral increase in width and the unusual — conditions cited for the Kaskaskia River, the changes noted were precisely those which could be expected in view of the changes in land use and landscape appear-— ance outlined earlier. Study of the values in table 5 for decrease, unchanged status, and increase for each characteristic in each — drainage system reveals the degree of these’ changes. ANNOTATED LIST OF FISHES Ninety species are included in our an- notated list of the fishes of Champaign County. One of these, Hybopsis aestivalis, is questionable for reasons given subse-— quently. A few other species, not in the annotated list, are known from streams in adjacent counties and may eventually be found in this county. These species of hypothetical occurrence are Carpiodes carpio carpio (Rafinesque), Moxostoma carinatum (Cope), Stizostedion canadense (Smith), all of which have been taken a short distance downstream in the Salt Fork of the Vermilion in adjacent Ver- milion County, and Etheostoma camurum (Cope), taken in the Middle Fork of the Vermilion in Vermilion County. A few other species, reported by Champaign County fishermen but not examined by us or documented by specimens, have not been included in our list. Of the 90 species in the annotated list, 74 were taken dur- ing 1959 or have been taken since. March, 1963 The fishes have an unusually complex synonymy. Accordingly, in the following list, the name applied to a Champaign County species by earlier authors is given in every case where the current name dif- fers from that in the literature. In several cases, the “species” of earlier investigators were composites of two or more species as now recognized. Because of these com- posite species, most of the existing speci- mens in the Thompson & Hunt collec- tions and a few in the Forbes & Richard- son collections have been re-examined and reidentified. A summary of collections for all three surveys is given. FR refers to Forbes & Richardson, TH to Thompson & Hunt, and LS to Larimore & Smith. The num- ber following the initials designates the number of localities represented ; the term “all drainages” following a number indi- cates that all drainage systems of Cham- paign County were represented. A “?” following FR or TH indicates some doubt as to whether the species involved was in- cluded in the nominal species of Forbes & Richardson (1908) or Thompson & Hunt (1930). Names of drainages from which species were collected are given in paren- theses. Amiidae Amia calva Linnaeus. Bowfin.—Several large adults taken by rowboat shocker from Kaufman’s Clear Lake, where they had been introduced for sport fishing. LS 1 (Kaskaskia). Lepisosteidae Lepisosteus osseus (Linnaeus). Long- nose gar.—A large adult taken by row- boat shocker in the Middle Fork where it leaves the county. The species was prob- ably missed by earlier investigators be- cause of its rarity in the county. LS 1 (Middle Fork). Hiodontidae Hiodon alosoides (Rafinesque). Gold- | eye—QOne specimen known from Cham- paign County. This specimen, taken on \ the Kaskaskia River at the lowermost | station in the county and reported as Hio- | don tergisus by Thompson & Hunt, is still | extant and is reidentified as H. alosoides. »| TH 1 (Kaskaskia). Larimore & SmirH: FISHES OF CHAMPAIGN CoUNTY 321 Clupeidae Dorosoma cepedianum (Le Sueur). Gizzard shad.—FR 3 (Kaskaskia), TH 2 (Sangamon), LS 12 (Embarrass, Salt Fork, Sangamon). Esocidae Esox americanus vermiculatus Le Sueur. Grass pickerel— Reported as FEsox ver- miculatus by Forbes & _ Richardson, Thompson & Hunt, and other early au- thors. FR 10 (Kaskaskia, Salt Fork, Mid- dle Fork, Sangamon), TH 26 (Kaskaskia, Embarrass, Little Vermilion, Salt Fork, Sangamon), LS 17 (all drainages). Catostomidae Carpiodes cyprinus hinei ‘Trautman. Central quillback carpsucker.—Reported as Carpiodes velifer by Forbes & Richard- son, Thompson & Hunt, and other early authors. FR 10 (Salt Fork, Middle Fork, Sangamon), TH 9 (Middle Fork, San- gamon), LS 27 (Salt Fork, Middle Fork, Sangamon). Carpiodes velifer (Rafinesque). High- fin carpsucker.—Reported as Carpiodes difformis by Forbes & Richardson, Thompson & Hunt, and other early au- thors. FR 8 (Kaskaskia, Salt Fork, Mid- dle Fork, Sangamon), TH 4 (Middle Fork, Sangamon), LS 9 (Salt Fork, Mid- dle Fork, Sangamon). Catostomus commersonit commersoni (Lacépéde). White sucker.—FR 14 (Salt Fork, Middle Fork, Sangamon), TH 63 (not 65 as stated: all drainages), LS 76 (all drainages except Little Vermilion). Erimyzon oblongus claviformis (Gi- rard). Western creek chubsucker.—Re- ported as Erimyzon sucetta oblongus, a composite of E. sucetta and E. oblongus, by Forbes & Richardson, Thompson & Hunt, and other early authors. There is no evidence that E. sucetta ever occurred within the county, although it is known from deep quarries in adjacent Vermilion County. FR 22 (all drainages except Lit- tle Vermilion), TH 43 (all drainages), LS 79 (all drainages). Hypentelium nigricans (Le Sueur). Northern hog sucker.—Reported as Ca- tostomus nigricans by Forbes & Richard- son, Thompson & Hunt, and other early authors. FR 7 (Salt Fork, Middle Fork, Sangamon), TH 27 (all drainages ex- 322 cept Little Vermilion), LS 42 (all drain- ages except Little Vermilion). Ictiobus bubalus (Rafinesque). Small- mouth buffalo.—A single specimen taken on the lower Sangamon River. FR 1 (Sangamon). Ictiobus cyprinellus (Valenciennes). Bigmouth buffalo—One_ specimen __re- ported from the lower Sangamon. TH 1 (Sangamon). Ictiobus niger (Rafinesque). Black buffalo—Reported as Ictiobus urus by Thompson & Hunt and known in the county by a single specimen taken on the lower Sangamon River. TH 1 (Sanga- mon). Minytrema melanops (Rafinesque). Spotted sucker—FR 15 (Kaskaskia, Salt Fork, Middle Fork, Sangamon), TH 4 (not 5 as stated: Kaskaskia, Salt Fork), LS 1 (Little Vermilion). Moxostoma anisurum (Rafinesque). Silver redhorse—TH 1 (Sangamon), LS 7 (Salt Fork, Sangamon). Moxostoma macrolepidotum macrolepi- dotum (Le Sueur). Northern redhorse.— Reported as Moxostoma breviceps by Forbes & Richardson, Thompson & Hunt, and other early authors, but later and until very recently called M. aureolum. FR 1 (Salt Fork), TH 6 (Kaskaskia, Sangamon), LS 8 (Sangamon). Moxostoma erythrurum (Rafinesque). Golden redhorse——Reported as Moxos- toma aureolum by Forbes & Richardson, Thompson & Hunt, and other early au- thors, who presumably based their identi- fications on specimens of this species. The superficially similar M. duquesnei, which the early authors did not distinguish from erythrurum, was not taken in the county during the 1959 survey and is not repre- sented among the Forbes & Richardson and Thompson & Hunt collections still extant. FR 11 (Salt Fork, Middle Fork, Sangamon), TH 22 (all drainages ex- cept Little Vermilion), LS 28 (Embar- rass, Salt Fork, Middle Fork, Sangamon). Cyprinidae Campostoma anomalum pullum (Agas- siz). Central stoneroller.—Reported as Campostoma anomalum by Forbes & Richardson, Thompson & Hunt, and other early authors. This fish is assignable to the subspecies C. a. pullum. FR 17 (Salt 2 Ittinois Natura History Survey BULLETIN Ss Vol. 28, Art. 2 Fork, Middle Fork, Sangamon), TH 64 (all drainages except Little Vermilion), — LS 102 (all drainages except Little Ver-— milion). Carassius auratus (Linnaeus). Gold- fish.—Several large specimens taken by rowboat shocker from Kaufman’s Clear Lake, where they had been introduced. Another adult was found in the Salt Fork | near Homer in 1955. LS 2 (Kaskaskia, Salt Fork). Cyprinus carpio Linnaeus. Carp.—FR 4 (Salt Fork, Middle Fork, Sangamon), TH 11 (not 9 as stated: Embarrass, Salt Fork, Sangamon), LS 56 (all drainages). Ericymba buccata Cope. Silverjaw min- now.—FR 22 (Kaskaskia, Salt Fork, Em- barrass, Middle Fork), TH 79 (all drain- ages), LS 78 (all drainages except Little Vermilion). Hybognathus nuchalis nuchalis Agas- siz. Western silvery minnow.—FR 4 (Salt Fork, Middle Fork, Sangamon), TH 9 (Kaskaskia), LS 9 (Kaskaskia). — Hybopsis aestivalis hyostoma (Gilbert). Ohio speckled chub.—Reported from the Middle Fork on the Champaign-Ford county line as Hybopsis hyostomus by Large (1903:19). The locality, which is” far removed from other records of the species, was either ignored or overlooked by Forbes & Richardson and Thompson & Hunt; inasmuch as Large’s specimen is” not extant for reidentification and addi- tional specimens have never been taken, the record is open to doubt. ¥ Hybopsis amblops amblops (Rafi- nesque). Northern bigeye chub—FR 6 (Salt Fork, Middle Fork), TH 8 (Em- barrass, Salt Fork, Middle Fork). ' Hybopsis biguttata (Kirtland). Horny- head chub.—Reported as Hybopsis ken- tuckiensis by Forbes & Richardson, Thompson & Hunt, and other early aw thors. FR 10 (Salt Fork, Middle Fork, Sangamon), TH 46 (Kaskaskia, Middle Fork, Sangamon), LS 70 (Kaskaskia, Salt Fork, Middle Fork, Sangamon). Hybopsis storeriana (Kirtland). Silvei chub.—A specimen from the Middle Fort reported by Forbes & Richardson. A see ond specimen, an individual 4.5 inche long taken on a hook in the Salt Forl River near Homer in July, 1952, was re ported to us by Dr. Marcus S$. Goldmar FR 1 (Middle Fork), LS 1 (Salt Fork) NN March, 1963 Notemigonus crysoleucas (Mitchill). Golden shiner.—Reported as gS Vol. 28, Art. 2 nored, by Forbes & Richardson (1908) 1 and all subsequent authors. The speci- — mens are no longer extant. Although fish collections by staff mem- — bers of the Illinois State Laboratory of Natural History, a parent agency of the Natural History Survey, were made as — early as 1882, no references to Champaign County fishes, except those by Large (1903:15, 19), appeared until Forbes — (1907) published a paper on the distribu- tion of certain Illinois fishes. Forbes & Richardson Records ~ The Forbes & Richardson distribu- — tional records were plotted on the maps — in an atlas accompanying The Fishes of — Illinois or were cited in the text. Al-— though fish nomenclature of 1908 differs — markedly from that of today, we are — virtually certain that the following species — as now recognized were included in the 48 collections of Forbes & Richardson: Dorosoma cepedianum Esox americanus Car piodes cyprinus 3 Car piodes velifer Catostomus commersoni Erimyzon oblongus Hypentelium nigricans Ictiobus bubalus Minytrema melanops a. Moxostoma macrolepidotum © Moxostoma erythrurum ‘2 Campostoma anomalum Cyprinus carpio Ericymba buccata Hybognathus nuchalis Hybopsis amblops re Hybopsis biguttata re Hybopsis storeriana 4 Notemigonus crysoleucas & Notropis atherinoides be Notropis boops Notropis chrysocephalus Notropis dorsalis Notropis heterolepis Notropis umbratilis Phenacobius mirabilis Pimephales notatus Pimephales promelas Pimephales vigilax Semotilus atromaculatus Ictalurus melas Ictalurus natalis Ictalurus punctatus penser 5 eo Ree a March, 1963 Noturus flavus Noturus gyrinus Noturus miurus Fundulus notatus Labidesthes sicculus A phredoderus sayanus Chaenobryttus gulosus Lepomis cyanellus Lepomis humilis Lepomis macrochirus Lepomis megalotis Micropterus dolomieui Pomoxis annularis Pomoxis nigromaculatus Etheostoma asprigene Etheostoma blennioides Etheostoma chlorosomum Etheostoma flabellare Etheostoma nigrum Percina caprodes Percina maculata Percina phoxocephala In addition to the species cited above are probably others. Forbes & Richardson’s nominal “Notropis blennius”’ was probably a composite of N. stramineus and N. vo- lucellus, their ““Notropis whippli” a com- posite of N. spilopterus and N. whipplei, their “Micropterus salmoides” a composite of M. punctulatus and M. salmoides, and their “Etheostoma coeruleum”™ a composite of E. caeruleum and E. spectabile. A\- though many of the early collections have been lost and cannot be reidentified, we are reasonably certain that 63 species were represented in the collections of Forbes & Richardson and that the 2 other species reported previously by Large (1903:15, 19) bring the total number of species col- lected in the county by 1901 to 65. Thompson & Hunt Records Although the material of Forbes & Richardson was cited in various revision- ary studies published between 1901 and (1928, no additional Champaign County records for this period were published in these taxonomic papers. Thompson & Hunt, in their 1930 pub- lication, chose to use the nomenclature of Forbes & Richardson, and many of their nominal species would have been difficult to assign had we not had much of their \material for reidentification. They claimed the addition of 13 species to the known fauna of Champaign County, but restudy Larimore & SmitTH: FISHES oF CHAMPAIGN COUNTY 329 of their specimens indicated that they ac- tually added the following 15: Hiodon alosoides Ictiobus cyprinellus Ictiobus niger Moxostoma anisurum Notropis amnis Notropis rubellus Noturus exilis Pylodictis olivaris Ambloplites rupestris Lepomis punctatus (probably introduced ) Anguilla rostrata (from adjacent Douglas County ) Ammocrypta pellucida Etheostoma gracile Etheostoma zonale A plodinotus grunniens Their nominal “Notropis blennius” in- cluded both N. stramineus and N. volucel- lus; their “Notropis whippli,’ both N. spilopterus and N. whipplei; and their “Etheostoma coeruleum,”’ both E. caeru- leum and E. spectabile. Whether their “Micropterus salmoides” also included M. punctulatus is not known, as the speci- mens have been lost. Thompson & Hunt believed that they missed only three species that had been previously recorded from the county, whereas they actually failed to rediscover the following six: Ictiobus bubalus Hy bopsis aestivalis Hybopsis storeriana Notropis atherinoides Notropis heterolepis Etheostoma asprigene The discrepancy is due to their ap- parent misidentification of Notropis athe- rinoides and their failure to include the two species recorded by Large (1903:15, 19). In all, Thompson & Hunt obtained 74 species, 59 of which had been recorded previously from the county. Almost half of the species recorded by both Forbes & Richardson and Thompson & Hunt showed an increase in number of stations and in number of drainages oc- cupied in the approximately 30-year pe- riod between the surveys. Many of the ap- parent increases in abundance are of doubtful significance because of the more intensive collecting program of ‘Thompson & Hunt; however, some of the apparent 330 increases in abundance appear to be sig- nificant, as will be shown later. “Thomp- son & Hunt believed that their data in- dicated a pronounced increase in the abundance and distribution of Semotilus atromaculatus, Ericymba buccata, and Micropterus dolomieui and suggested the recent arrival in the county of dplodi- notus grunniens. A number of species showed apparent decreases in abundance and distribution. Some of the apparent decreases were probably the result of cyclic changes in populations; others probably represent gradual disappearance of species. Thomp- son & Hunt cited Hybognathus nuchalis and Minytrema melanops specifically and noted that several other species seemed to have declined in abundance. Comparison of the distribution maps of Forbes & Richardson and those of Thompson & Hunt suggests that a reduction in numbers of stations represented, in numbers of drainages occupied, or in numbers of both, also occurred in the following species: Dorosoma cepedianum, Carpiodes cy- prinus, C. velifer, and Moxostoma macro- lepidotum. However, in these species the apparent decrease in abundance and dis- tribution was probably not real, as there was no evidence of their decrease from 1928 to 1959. Moreover, all are large fishes characteristic of deep pools and can be easily missed when collecting is done principally with a 10-foot minnow seine. Another group of fishes, all of which are creek species of small size, also showed some reduction in numbers of stations or drainages occupied, or both; but their ap- parent reduction is assumed to have been due to only a temporary decline in their populations about 1928, as in 1959 none showed evidence of reduced occurrence. A third group of species, to be cited later, showed striking decrease in abundance and distribution between 1901 and 1928. Their continued decline is documented by more recent data. Investigations Between 1929 and 1959 Although some observations on fishes of Champaign County were made between 1929 and 1959 by various fishermen and by personnel of the Illinois Natural His- tory Survey and the University of Illinois, no records of unusual interest were pub- ItLtiNots NarurAL History SurRvVEY BULLETIN Vol. 28, Art. 2 lished. Several of Thompson & Hunt's records were cited by Luce (1933), who utilized their collections from the head- waters of the Kaskaskia in his study of that river, and by O’Donnell (1935) in his list of Illinois fishes. During the next several years, material from Champaign County was cited in several revisionary studies, but none of these contributed new distributional information. Although no concerted effort was made to obtain col- lections from the county, occasional field — work by two University of Illinois bi- ologists, the late H. J. Van Cleave and H. H. Shoemaker, and by ecology classes at the University contributed to the knowledge of local fishes. Personnel of the Natural History Survey, with head- quarters in the center of the county, have been alert to major changes in field popu- lations and to alterations of habitats in the area; they have supplemented their own observations through contacts with fishermen and other local observers. Recent Survey Records Collections in 1959, and subsequently, added 10 species to the known fauna of Champaign County. Six of these (4 mia calva, Carassius auratus, Ictalurus nebu- losus, Gambusia affinis, Roccus mississip- piensis, and Lepomis microlophus) are known to be introduced species; three (Lepisosteus osseus, Noturus nocturnus, and Percina sciera) are native and pre- sumably were always present but were overlooked by previqus investigators; one (Notropis lutrensis) recently extended its range eastward into Champaign County. Our collections failed to reveal the pres-— ence of 11 species that were taken 30 years before by Thompson & Hunt: Ictiobus cyprinellus Ictiobus niger Hybopsis amblops Notropis amnis Notropis boops Opsopoeodus emiliae Pimephales vigilax Noturus exilis Lepomis punctatus Etheostoma chlorosomum Etheostoma gracile Our collections also failed to inclu three species (Ictiobus bubalus, Hy bopsis aestivalis, and Notropis heterolepis) taken 0? March, 1963 Larimore & SMITH: FISHES GF CHAMPAIGN CoUNTY 331 Table 6—Summary of collections and the number of species taken and recorded in Cham- paign County by various collectors. Figures in parentheses indicate the numbers of collecting stations. PRE-FORBES & FORBES & THOMPSON LARIMORE Sea RICHARDSON RICHARDSON & HUNT & SMITH (G2) (48) (126) (152) Number of RceIeSitAKeN sa =. 2 ees 2 63 74 74 Number of previously unrecorded species taken 2 63 15 10 Number of previously recorded species retaken 0 0 59 64 Number of previously recorded species not taken ——— 0 2 6 16 Total number of species recorded (cumulative) 2 65 80 90 in the county 60 or more years ago by Forbes & Richardson or by Large. —Ttwo species (N. atherinoides and Etheostoma asprigene) taken by Forbes & Richardson, but not by Thompson & Hunt, were re- discovered in the county in 1959. In all, our collections represented 74 species, 64+ of which had been previously reported from Champaign County. The number of collecting stations, number of species rep- resented, and other data for each survey are summarized in table 6. Summary of Changes Over 60-Year Period With full realization that fish popula- tions may vary from one year to the next and that comparison of results of three widely spaced surveys could thus lead to erroneous inferences, we believe that cer- tain changes are demonstrable in the Champaign County fish fauna over the period of study reported here. (In this paper, occurrence of a_ species is mea- sured in relation to both the number of localities or stations represented and the number of drainages in which it was found. ) Evidence provided by the three surveys reveals numerous changes in occurrence of the fish fauna of the county. Of the 9 species added in 1959, at least 1 (Notropis lutrensis) appeared to have dispersed nat- urally from the west, and 15. species, which presumably had always been present in the county, showed increases in abun- dance and in number of drainages occu- pied. hese 16 species, the percentage of stations in which they occurred, and the number of drainage systems in which they were found in each survey are listed in table 7. Increased occurrence of these 16 species is suggested by scrutiny of the dis- tribution maps, figs. 15-70, pages 362-75. On the basis of table 7, we could as- sume that the large fishes (Pylodictis olivaris, both species of Moxostoma, Mi- cropterus dolomieui, and Cyprinus carpio) appeared to be more common in 1959 than formerly because the modern collecting apparatus used was more efficient than seines in sampling deep pools. Improved sampling methods could conceivably ex- plain the slight increases in occurrence shown for P. olivaris, the two species of Moxostoma, and part of the increase in occurrence shown for C. carpio, which is easily shocked. It has been suggested that the mush- rooming of Cyprinus carpio populations within the past 30 years could be as- sociated with the increased water pollution in the same period. Perusal of the list of species in table 7 reveals that the two other pollution-tolerant fishes, Notropis umbratilis and Semotilus atromaculatus, showed only modest increases in abun- dance in this period but that their great increase in abundance occurred much earlier, some time between 1899 and 1928. Moreover, gains of equal magnitude can be observed in such pollution-intolerant species as N. rubellus and Hypentelium nigricans. Notropis rubellus, N. dorsalis, and N. lutrensis are of particular interest because 332 Table 7.—Species showing increases in frequency of occurrence (per cent of stations in which each species was taken) in Champaign County i in three surveys; for each species is civemy i the number of drainages in which it was taken in each survey. ILttNo1is NATURAL History SURVEY BULLETIN Vol. 28, Art. Forses & RICHARDSON THoMpson & HUNT Larimore & SMITH - SPECIES Per Cent of| Number of | Per Cent of| Number of | Per Cent of| Number of — Stations | Drainages| Stations | Drainages| Stations | Drainages Notropis lutrensis 0 0 0.0 0 13.8 2 Ambloplites rupestris 0 0 0.8 1 10.5 3 Moxostoma anisurum 0 0 0.8 1 4.6 2 Pylodictis olivaris 0 0 0.8 1 2.6 3 Notropis rubellus____ 0 0 2.4 1 3.9 1 Noturus flavus 2.1 1 4.0 3 14.5 3 Notropis dorsalis. 2.1 1 4.0 1 18.4 3 Moxostoma macrolepidotum Pah 1 4.8 2 5.3 1 Micropterus dolomieui 2.1 1 ees, 3 24.3 4 Cyprinus carpio 8.3 3 8.6 3 36.8 6 Hypentelium nigricans ~ 14.6 3 21.4 5 27.6 5 Notropis umbratilis __ 16.7 2 54.8 6 63.8 6 Semotilus atromaculatus 18.7 3 80.1 6 83.0 6 Notropis chrysocephalus 18.7 2 42.9 4 52.0 5 Hybopsis biguttata —— - 20.8 3 36.5 3 46.0 4 Campostoma anomalum 35.4 3 50.8 5 67.1 5 they are peripheral populations, N. rubel- lus reaching its southernmost point of dis- tribution, at least in eastern [llinois, within Champaign County, and the other two reaching their easternmost limits of distribution in the county. N. rubellus ap- pears to have extended its range south- ward into the county between 1899 and Table 8.—Species showing decreases in frequency of occurrence (per cent of stations in which each species was taken) in Champaign County i in three surveys; for each species is given ( the number of drainages in which it was taken in each survey. 1928 and to have replaced the allied atherinoides in both tie where ru- bellus was found in 1959. N. dorsalis ha been known in the county for at lea years; there is evidence from anotha ; source, in addition to the Champaign — County data, that its range is graduall shifting eastward. A similar trend Fo-Bes & RICHARDSON* THOMESON & HUNT Larimore & SMITH — SPECIES rca Renee ae anaes Naber ve Per Number all Stations’ | DAMAEEs Grations | | | Sta Drains Lepomis humilis ~~ 33.3 4 10.3 3 5.9 3 Minytrema melanops —_-. 312 4 3.2 2 0.6 1 Ictalurus melas 25.0 4 9.5 5 4.6 5 Labidesthes sicculus 125 2 4.0 1 2.0 1 Pomoxis nigromaculatus 14.6 3 2.4 1 1.3 1 Esox americanus — 20.8 4 20.6 5 11.2 6 Chaenobryttus gulosus - 6.2 1 0.8 1 0.6 1 Hybopsis amblops 12:5 2, 6.4 3 0.0 0 Pimephales vigilax 12.5 1 ae 2 0.0 0 Etheostoma chlorosomum Fal 1 0.8 1 0.0 0 Notropis boops —------ zal 1 1.6 1 0.0 0 Opsopoeodus emiliae Dall 1 1.6 1 0.0 0 Notropis heterolepis 4.2 2 0.0 0 0.0 0 Ictiobus bubalus — 2.1 1 0.0 0 0.0 0 Hybopsis aestivalis 2.1 1 0.0 0 0.0 0 *Includes Opsopoeodus emiliae and Hybopsis aestivalis recorded by Large (1903:15, 19) March, 1963 shown by N. lutrensis, which entered the county between 1928 and 1959. dmblo- plites rupestris and Micropterus dolomieui show an irrefutable increase in abundance and occurrence within Champaign Coun- ty, but there is no evidence that their ranges within the state have changed. These species would have been benefited by the increased stream gradient and lower maximum water temperatures that may have resulted, as suggested in the sec- tion on Changes in Stream Habitats, from drainage and dredging operations. Similarly, Hypentelium nigricans, N. chrysocephalus, Hybopsis biguttata, No- turus flavus, and Campostoma anomalum show decided, if inexplicable, increases in occurrence within the county, but their over-all ranges within the state appeared to be the same in 1959 as 60 years before. On the basis of evidence from the three surveys, 15 species exhibited an equally striking decrease in abundance and in shrinkage of distributional pattern within the county over the 60-year period of study. These species, the percentage of stations in which they were found, and the number of drainages in which they were taken at each survey are listed in table 8. Data for the entire period covered by the three surveys indicate that Ictiobus bubalus, Hybopsis aestivalis, and Notropis heterolepis disappeared from Champaign |County before 1928. N. heterolepis, if Forbes & Richardson correctly identified the specimens to which they assigned this name, is of particular interest because it occurred in two different drainage systems prio to 1899 and probably disappeared with the draining of the once extensive prairie marshes. J. bubalus may be ex- pected to be taken again in Champaign ‘County, for it occurs in large streams only ; few miles outside the county. Hybopsis amblops, Pimephales vigilax, Etheostoma chlorosomum, Notropis boops, and Opsopoeodus emiliae may have de- clined in numbers by 1928; they disap- peared between 1929 and 1959. The re- maining seven species listed in table 8 are still present, but they are much less com- mon than formerly. All of them except Esox americanus suggest that their marked decline in the county occurred between 1899 and 1928. One, Minytrema mela- Larimore & SmiITH: FISHES oF CHAMPAIGN COUNTY 333 nops, was described by Large (1903:12) as “abundant in the Wabash basin and in the headwaters of the Kaskaskia” and ‘“‘ap- parently prefers the weedy prairie creeks in situations where it is abundant.” E. americanus was evidently about equally common in 1899 and 1928 but had de- creased sharply by 1959, presumably be- cause of the destruction by dredging of its preferred habitat (pools with luxuriant aquatic vegetation). The extirpation of six other species (Ictiobus cyprinellus, I. niger, Notropis amnis, Noturus exilis, Lepomis punctatus, and Etheostoma gracile) from Champaign County is almost certain; they have not been included in table 8 because informa- tion regarding their abundance, or even their presence, was unavailable prior to the 1928 investigation. Of the extirpated species, E. gracile, N. exilis, and Hybopsis amblops are noteworthy because they were, until 1928, peripheral populations in the county. The northernmost record in the range of E. gracile, the eastern- most record in the range of N. exilis, and the westernmost record of H. amblops, at least in this region, were in Champaign County. Within the past 30 years, shrink- age in the ranges of these three species, re- spectively to the south, west, and east, has occurred. ‘This shrinkage is evident over the state as a whole as well as within Champaign County. Despite the impressive changes in abundance and distribution of the species discussed in the paragraphs above, it is dif- ficult to describe the changes in the Champaign County fish fauna as radical, for roughly half of the species showed no decided trends. Examination of distribu- tion maps, figs. 15-70, that accompany this report will reveal that the occurrence of several species was remarkably similar throughout the 60-year period of observa- tion. Several species exhibited consider- able changes in distribution but these spe- cies cannot be regarded as being any more or less common, or more or less widely distributed, in the county in 1959 than they were in 1928 or 1899. In view of the great changes in land use, in the stream courses, and in the stream habitats that occurred in the county over a 60- year period, and the catastrophic effects of the several drought years since 1930, 334 Table 9.—The number of species of fish taken and recorded in each of the six Champaign County drainages and the number of species restricted to each of these drainages. ILtiInois NATURAL History SURVEY BULLETIN Vol. 28, Art. 2. 2 MIDDLE LITTLE ANGAMON / K KAsk vi SANG SALT For rane ASKIA Vinee EMBARRASS if 3 2 3 2 o 2 o 2 o 2 3 _ S ce Ep ATR) "Ble i) een Rr) £8 2.0 ES 2 Eo Se URVEY Sal fa) sal ee] sa| $a) Sal 82] sa| 2) on oa o os oS | of o.E}] of o&| os oS} os oS] of M's ae M's Ms ms Ms Ms | ha | Ms | ee | | . h MH ~ SA} BO) $2) SO) $0) $0) SO) $O) JO) 6Q | SQ) BAT Ve V6 Og Vo Ve Ve Sg Vo Og 3) 3) (3) ra ge) 28) g5) a8) ge) ge) oe) ee) oe) eee Dn GL 7) n n DN n D n D v2) n a z : — Forbes & ‘ Ricken x son. 40 5 47 9 24 3 18 2 8 0 Thompson & unt = 50 13 4] 7. 36 4 14 4+ 14 0 25 0 Larimore & Smith 54 6 51 3 47 4 39 5 18 1 32 0 ‘Rotaltie 67 fA 64 3 55 3 51 4 20 1 36 0 it is indeed astounding that many of our species were still present in the same streams in 1959 and probably in approxi- mately the same numbers then as 30 and 60 years previously. Results of an analysis of distribution of species by drainage systems are sum- marized in table 9. It will be seen that Forbes & Richardson found the Salt Fork drainage both the richest in number of species, with +7, and the most distinctive, with 9 species occurring there exclusively. On the basis of these same criteria, they found the Sangamon to be second, the Middle Fork third, the Kaskaskia fourth, and the Embarrass fifth. They made no collections in the Little Vermilion drain- age. About 30 years later, Thompson & Hunt found the Sangamon richest in spe- cies and most distinctive, with a total of 50 species, 13 of which they did not find elsewhere. Other drainages ranked as fol- lows: Salt Fork, Middle Fork, Kaskaskia, Embarrass, and Little Vermilion. Our findings were similar to those of Thomp- son & Hunt, except that we found fewer species restricted to a single drainage, and no species restricted to the Embarrass drainage. The most significant results of this analysis, aside from the richness of the fauna in each drainage, are the number of species restricted to a drainage system. More than 10 per cent of the 67 species in the Sangamon, almost 9 per cent of th 51 species in the Kaskaskia, almost 6 per cent of the 55 species in the Middle Fork, roughly 5 per cent of the 20 species ins the Little Vermilion and of the 64 species — in the Salt Fork occurred only in their respective drainages. None of the 36 species in the Embarrass occurred exclus sively i in that drainage. This lack of spe- cies distinctiveness for the Embarrass i clearly evident on the distribution — We can express distributional changes by examining the drainage systems and — tallying the number of changes observable when the Thompson & Hunt list of spe cies is compared with that compiled by Forbes & Richardson and the Larimore é Smith list of species is compared with thai compiled by Thompson & Hunt. A sum mary of these changes in presented in table LO: Table 10 indicates that the greatest number of changes between the Forb & Richardson and the Thompson & Hu surveys occurred in the Middle Fo drainage; 30 species were taken in one Of — these surveys but not the other. The least number of changes occurred in the Embar — rass; 21 species were taken in one of these surveys but not the other. No collections — were made in the Little Vermilion BD Forbes & Richardson. Within the approx mately 30 years between the survey 0 Forbes & Richardson and the survey OF March, 1963 Table 10.—Changes (increases or decreases) between surveys (FR=Forbes & Richardson; TH=Thompson & Hunt; LS=Larimore & Smith) in the number of species of fish in Champaign County drainages. Changes include both the taking of species not previously taken and the failure to retake species previously taken in a drainage. Forbes & Richardson made no collections in the Little Vermilion. TOTAL DRAINAGE FR-TH| TH-LS| Cyancgs measicaskia- 27 20 47 Middle Fork 30 15 45 Sangamon ______ 29 LS 44 Sale Pork ._.. 22 17 39 Pmbarrass ___. 21 11 32 Little Vermilion te 8 8 Tctal changes 129 86 215 Thompson & Hunt, a total of 129 changes in distribution occurred in the five drain- age systems considered here. Between 1928 and 1959, the greatest number of changes occurred in the Kaskaskia; the least num- ber of changes occurred in the Little Ver- milion drainage. Within the period be- tween 1928 and 1959, a total of 86 changes occurred in the six drainages of the county. For the over-all period of study, approximately 60 years, the greatest number of changes occurred in the Kas- kaskia drainage. If changes in the occurrence of fish reflect the amount of modification of a stream and its habitats, it should follow during the first 30 years of this century than during the second 30 years. This assumption is substantiated by the histori- cal record of land use and can be observed E much greater modification occurred by noting, in table 10, the interval when the greatest changes in species composition occurred. It should also follow that the most extensive changes in land use early in this century were in the Middle Fork jand Sangamon basins and, after 1928, in jsmall amount of change in the Little Ver- milion is probably due to its small size and jcomparatively small number of habitats; only the extreme headwaters of this drain- age are in Champaign County. : Kaskaskia and Salt Fork basins. ‘The ECOLOGICAL ASSOCIATIONS Ecological associations can be drawn between a species of fish and various en- | | | Larimore & SMITH: FISHES OF CHAMPAIGN COUNTY 335 vironmental factors comprising its habitat, or between a species of fish and other species of fishes with which it is found. However, a clear separation of the influ- ences of the physical environment from those exerted by fishes is often difficult or impossible. Species Associated With Various Stream Habitats ‘The stream habitats defined in table 4 on the basis of water velocity, depth, and area of drainage basin contained fish popu- lations characteristic of each. As shown in the tabulations below, some species taken in the Champaign County surveys were limited in their occurrence to a specific habitat, whereas others were more gen- erally distributed. Our assignment of a particular species to a particular habitat was complicated by seasonal changes in fish distribution, differences in distribution of young and adult fish, and lack of uni- formity throughout each habitat. Species of Rivulets and Small Creeks Etheostoma spectabile Campostoma anomalum Semotilus atromaculatus Fundulus notatus Pimephales notatus Erimyzon oblongus, young Catostomus commersont, young Lepomis cyanellus, young Ictalurus natalis, young Ictalurus melas, young Species of Large Creeks Rifles: sand and fine gravel Ericymba buccata Etheostoma spectabile Notropis dorsalis Campostoma anomalum Phenacobius mirabilis Riffles: gravel and rubble Etheostoma caeruleum Etheostoma blennioides Etheostoma flabellare Pools: shallow, moderate current Notropis chrysocephalus Hybopsis biguttata Semotilus atromaculatus Catostomus commersoni Notropis stramineus Notropis spilopterus ILLINOIS NATURAL Pimephales notatus Noturus miurus Etheostoma nigrum Cyprinus carpio, young Moxostoma spp., young Carpiodes spp., young Hypentelium nigricans, young Percina maculata Carpiodes cyprinus Hybognathus nuchalis Notropis lutrensis Pools: deep, sluggish Lepomis megalotis Micropterus dolomieui A mbloplites rupestris Esox americanus Erimyzon oblongus Notemigonus crysoleucas Lepomis humili> Pimephales promelas A phredoderus sayanus Lepomis macrochirus Ictalurus natalis Ictalurus melas Noturus gyrinus Notropis umbratilis Lepomis cyanellus Fundulus notatus Species of Small Rivers Riffles: sand and gravel Notropis whipplei Ammocrypta pellucida Phenacobius mirabilis Notropis dorsalis Riffles: boulders and rubble Hypentelium nigricans Etheostoma blennioides Noturus flavus Notropis rubellus Etheostoma zonale Pools: shallow, moderate velocity Moxostoma erythrurum Percina phoxocephala Moxostoma macrolepidotum Carpiodes velifer Percina caprodes Hybognathus nuchalis Lepomis megalotis Lepomis cyanellus Pools: deep, sluggish Micropterus punctulatus Moxostoma anisurum Cyprinus carpio Dorosoma cepedianum Micropterus salmoides History Survey BULLETIN 100 creek chubs over 30% sand Vol. 28, Art. 2 Pomoxis annularis Pylodictis olivaris Lepomis macrochirus A plodinotus grunniens Ictalurus natalis Ictalurus melas Species Associated With Various Ecological Factors From each of our quantitative samples, the number and weight of each species per 100 square yards were recorded on {BM sorting cards along with measure- ments or appraisals of the following 13- ecological factors of the habitats: (1) average depth, (2) average width, and (3) average water velocity; composition — of the bottom materials as percentage of — (4) clay, (5) silt, (6) sand; (7) sila and sand, (8) oravell and (9) rubble; occurrence of (10) aquatic vegetation, (11) debris, and (12) bank vegetation; degree of (13) water turbidity. Each of these ecological factors was assigned numerical values to express the total —o range of field measurements (examples: depth in feet, per cent sand). For each value of an ecological factor (for example, over bottom materials that were 30 per cent sand), we determined: (1) the total number of individuals of each species associated with the value. Example: 100 creek chubs taken over 30 per cent sand. . (2) the number of collections in which this species occurred. Example: Creek chubs occurred in 10 collections. (3) the total number of collections associ- ated with the ecological value. Example: Bottom materials com- posed of 30 per cent sand were found in 20 collections. ' (4) the average number of fish of eac species found with the value, figure by dividing (1) by (3). Example: 20 collections over 30% sand 5 chubs per collection over 30% san (5) the per cent of collections associate with the ecological value that con tained the species, figured by dividin (2) by (3). March, 1963 Example: 10 collections of chubs 20 collections over 30% sand 50 per cent of collections over this bottom contained chubs Thus, in the examples above, five creek chubs were taken per collection over 30 per cent sand bottom material, and creek chubs were present in 50 per cent of such collections. Ecological associations were determined for collections from each drainage system and then for the entire county. The association figures revealed (1) ecological factors that comprised the gen- eral habitat of each species (used in assign- ing species to stream habitats in the pre- ceding section) ; (2) inconsistencies that appeared when a species was related to a specific ecological factor in one stream system and not in another; and (3) the absence of any single factor that deter- mined the distribution or abundance of most species. Such ecological associations may be of definite value in defining the general habi- tat of a species but are quite misleading in determining its environmental require- ments, for the influences of each environ- mental factor in a natural habitat cannot be separately evaluated. We cannot be sure just which factor or factors in a habitat have a controlling influence on a species. For example, gizzard shad showed a high degree of association with deep, quiet pools. However, they may have been responding not to depth or to low water velocity but to the soft sands and silts usually found in such pools. Too, a species might have been closely associated with a specific factor that did not comprise a noticeable part of the habi- tat. A few species were closely restricted to rather specialized habitats. The restric- tions, while quite obvious during field collecting, were not always shown by our calculations. Some of the most notable examples were Ammocrypta pellucida, which occurred only in clear water flow- ing over clean sand; Esox americanus, which reached its greatest abundance in quiet, silt-bottomed pools choked with vegetation; Noturus flavus, which seemed Laritmore & SMITH: FISHES OF CHAMPAIGN COUNTY S72 to prefer deep riffles or shallow pools with moderate current and scattered rub- ble and flat rocks; and 4 phredoderus say- anus, which was invariably in mud-bot- tomed pools of streams with little current. However, in general, most fishes showed a remarkable plasticity in their environ- mental tolerance. Species Associated With Other Species Associations between species can be determined (1) through examining which species are mutually associated with a set of ecological factors and (2) through ex- amining the mutual occurrence and abun- dance of two or more species. The degree of association between pairs of several kinds of common Champaign County fishes was determined by calculating the coef- ficient of correlation (r) between their numbers in 100 square yards of stream. Coefficients were determined for the col- lections from each drainage system, as well as for the entire county. Several definite and sometimes surprising associa- tions were evident. Notropis dorsalis—Ericymba buc- cata.—Champaign County is on the edge of the range of each of these species, No- tropis dorsalis becoming more abundant westward and Ericymba buccata becoming more abundant eastward. Because of the east-west separation in distribution, these two species usually do not occur abun- cantly in the same drainage system. They have been considered ecological equiva- lents, and competition between the two has been implied. Trautman (1957:376) noted the shrinking in size of the Ohio range of N. dorsalis and the invasion and great increase in numbers of FE. buccata in a territory formerly occupied by dorsalis. However, in our Sangamon River collec- tions, where both species were abundant, they occurred together in a highly signifi- cant degree (P less than 0.01) of associ- ation, table 11. This situation indicates their preference for similar habitats and disputes the idea that there is strong competition between the two. N. dorsalis, although occurring in two other Cham- paign County drainages (Kaskaskia and Middle Fork), was abundant only in the Sangamon, so that further comparisons could not be made. 338 Ittinois NAruRAL History SurvEY BULLETIN Vol. 28, Art. 2 Table 11.—Degree of association between four species of fish in the Sangamon drainage. Correlation coefficient (r) of 0.438 is significant at the 0.02 level. Notropis Notropis Ericymba SPECIES chrysocephalus dorsalis buccata Erimyzon oblongus 0.668 0.587 0.187 Notropis chrysocephalus 0.874 0.464 IN GUFDDES CLOT SALIR ee ete eee ea | aN hae, | ae ae eee 0.771 Table 12.—Degree of association between four species of fish in the Middle Fork drainage. Correlation coefficient (r) of 0.934 is significant at the 0.02 level. Sanit Erimyzon Notro pis Phenacobius oblongus chrysocephalus mirabilis Catostomus commersoni_—_____------------------- 0.977 0.965 0.978 Erimyzon oblongus——. ns 0.958 0 935 Notropis chrysocephalus ae 0.973 Notropis chrysocephalus — Erimy- zon oblongus.—These species formed one of the least expected associations ob- served among Champaign County fishes, occurring in a significant (P 0.02 or less) association in three of five drainage systems, fig. 12. In the Sangamon drain- age they were closely associated with the two species previously discussed, table 11. In the Middle Fork drainage, however, they formed a strong association with Phenacobius mirabilis and Catostomus commersoni, table 12. Catostomus commersoni — Phena- cobius mirabilis. — These two species occurred in significant associations (P 0.02 or less) in three of the five Cham- paign County drainages considered, as well as in the county-wide analysis. They SPECIES . crysoleucas . biguttata commersoni mirabilis oblongus . chrysocephalus ———— dorsalis buccata . umbratilis . Nigricans ZS2MZ2mveOr2 were significantly associated with Erimy- zon oblongus and Notropis chrysocephalus in the Middle Fork drainage, table 12. Both species were closely associated with Hybopsis biguttata in the Salt Fork drain- age, fig. 12. Miscellaneous Associations.— Several species showed different associ- ations in different stream systems; for example, Notropis umbratilis was signifi- cantly (P 0.02 or less) associated with such species as Hypentelium nigri- cans, Notemigonus crysoleucas, Notropis chrysocephalus, Phenacobius mirabilis, and Erimyzon oblongus, each association in a different stream. This lack of similarity or consistency in associations seems to suggest little interdependence between species but rather dependence of certain SANGAMON SALT FORK KASKASKIA MIDDLE FORK EMBARRASS ALL STREAMS ee _ _—_— ee @ . eS ae \— 80. o—_—__@—__o—__ 1. $e a @ o__—_—_————=3 Fig. 12.—Significant associations of several fishes in five drainages of Champaign County. — The coefficient of correlation (r) was better than the 0.02 level of significance except in the column — “All Streams,” where the associations between Notropis dorsalis and Ericymba buccata and between N. dorsalis and Hybopsis biguttata were significant only to the 0.03 level. March, 1963 species on certain ecological factors. ‘These factors may occur together in one stream system, thus bringing two species together, or they may be separated in another stream system, thus separating species. Two species might occur together tempo- rarily or abnormally, as during periods of low water when many species may be forced into constricted water areas. Thompson & Hunt (1930:66) stated, “Most instances of the association of dif- ferent species of fishes are explained satis- factorily by similar environmental prefer- ences.’’ However, they pointed out a very significant exception to this statement in their discovery of a close association be- tween Hybopsis biguttata and Notropis chrysocephalus. For these two species, they suggested a direct dependence, at least at some stage in the life cycle. Our 1959 collections revealed a significant (P less than 0.01) association between these two minnows when all the collections for the county were considered together, but no consistency of association in any of the separate drainage systems, even though both species were taken in rather great numbers in four of the systems. GENERAL ABUNDANCE AND OCCURRENCE The use of collecting methods in 1959 that differed from those of 1928 contribu- ted to the difficulty of comparing the two Larimore & SmITH: FISHES GF CHAMPAIGN COUNTY 339 surveys with respect to the general abun- dance and occurrence of fishes as recorded. Some of the variables in such compari- sons were eliminated by consistently fol- lowing throughout each survey a proce- dure adapted to it and by excluding from consideration any stations that in either survey were influenced strongly by pollu- tion or that were not visited by both sur- vey parties. Seventy-one collections were then available for comparison. Average Number of Species Per Station A consistently larger number of species per station was found in collections taken in the 1959 than in the 1928 survey. The average was 13.2 species per station in 1928 and 19.0 in 1959; the ratio was 1:1.4, table 13. The samples taken in the later survey were considerably larger nu- merically and thus might be expected to contain a higher percentage of those species present at the collecting stations. In the two surveys, the drainages were in the same order with respect to average number of species per station; for example, in each survey, the Middle Fork had the largest number of species per station and the Embarrass the smallest number. In the 1959 survey, quantitative col- lections from the _ blocked-off stations produced between 88 and 97 per cent of the total number of species collected at Table 13—Average number of species per station and average number of fish per 100 square yards taken in 1928 and 1959 at 71 stations (not noticeably affected by pollution) in five major drainages of Champaign County (no quantitative samples were taken from the Little Vermilion) ; also, average number of pounds of fish per 100 square yards in 1959. AVERAGE NUMBER OF AVERAGE NUMBER OF SPECIES Fist Per 100 SQUARE PER STATION Walean ; AVERAGE NUMBER OF NUMBER POUNDS OF aloe OF 1928 1959 | FISH PER STATIONS = 100 SQUARE ; Ratio Ratio YARDS Total |Quanti-| Total | 1999:1959 | 1928 | 1959 | 1928:1959| in 1959 Collec-| tative | Collec- tion |Sample| tion Middle Bork. 5 20.6 30.4 31.4 1S 553 286 1: 0.5 5.10 Sangamon 28 73 20.1 21.9 ets 468 562 1 LR ee 2.89 Salt Fork. 18 9.1 14.4 15.3 ees 429 470 1 ia | 2.80 Embarrass 9 6.8 12.6 14.3 2 185 571 ASE 1.74 Kaskaskia 11 EZ 1327, 5-5 1:1.4 202 150 LsOF7 0.90 All systems 71 13-2 17.4 19.0 1: 1.4 387 457 j et YA 257 340 any site; in other words, we added approximately 10 per cent more species by “cruising” with a seine in adjacent habitats. With the small amount of effort expended, ‘cruising’ furnished desirable additions to the collections. Average Number of Fish Per 100 Square Yards Although the average numbers of fish per 100 square yards collected in both surveys varied greatly from stream to stream, table 13, the county averages for the two surveys did not differ greatly; the ratio of the 1928 to the 1959 average was 1:1.2. The most striking difference between the two surveys was that the Middle Fork produced the greatest num- ber of fish per 100 square yards in 1928 and next to the lowest number in 1959, whereas the Embarrass yielded the lowest number in 1928 and the highest number in 1959. There was no apparent habitat change that might account for this dif- ference. A difference of the same kind was not evident in the number of species taken or in the weight of fish collected in the two surveys of these streams. The highest ratio of increase from 1928 to 1959 in the number of species as well as in the number of fish collected per 100 square yards occurred in the Embarrass, although in the 1959 survey the number of species and the pounds collected in the stream were low, table 13. Average Weight of Fish Per 100 Square Yards The weights of Champaign County fish taken in 1959 could not be compared with those taken in 1928 because there were no exact weight data from the Thompson & Hunt survey. Thompson & Hunt (1930:39) estimated that they took 150 pounds of fish per acre in the 1928 collections. In the 1959 survey, the num- ber of pounds per 100 square yards varied from 0.9 in the Kaskaskia to 5.1 in the Middle Fork and averaged 2.6 for the entire county. This county average is equivalent to 124.4 pounds per acre. The poundage figures from the 1959 survey should not be regarded as repre- senting the total population present in any of the areas fished. Using the electro- fishing equipment employed in the 1959 I_ttinois NatrurAL History Survey BULLETIN Vol. 28, Art. 2 survey of Champaign County to fish Jor- dan Creek, a small stream in adjoining Vermilion County, Larimore (1961 :3—5) took an average of 54 per cent of the weight and 51 per cent of the number of the fish population present in the areas fished. The Jordan Creek population taken by electrofishing and other means amounted to nearly 25,000 fish weighing 163.9 pounds per acre. If the same rate of electrofishing success applied to our — Champaign County collections, the total populations would have been close to an average of 250 pounds per acre for the stations worked in 1959. DISTRIBUTION AND STREAM SIZE Thompson & Hunt, using their 1928 Champaign County collections, explored both the composition and the size of fish populations in relation to stream size, ex- pressed as square miles of drainage basin at point of collection. They related stream sizes to the numbers and weights of fish, to the average sizes of fish taken, to the number of species, and to the distribution of various species. They grouped their collections into 10 classes according to stream size at the collecting stations, be- ginning with stations having 0.51.0 square mile of drainage and doubling the stream sizes up to the class of 256.0- 512.0 square miles. Relationships With Stream Size We have analyzed quantitative data from the 1959 survey in a manner similar to that used by Thompson & Hunt in or- — der to determine whether the 1959 collec- tions support the conclusions of Thompson — & Hunt (1930:41-6), given in italics following paragraph headings below. In-— cluding only those stations receiving no es noticeable pollution and those visited in~ both 1928 and 1959, table 14, we plotted our data for 1959 in fig. 13 to corre- spond roughly to the treatment shown by Thompson & Hunt in their fig. 6; that — is, we combined the data for our two | smallest classes of stream size and for our three largest classes of stream size. Oe Thompson & Hunt combined the data for — their three smallest and their three largest classes of stream sizes. We made no quan- — titative collections from the two smallest eee eee — . Sel oor ———_——— I PR AE PEPE PLIT Fm Ve wr wee om March, 1963 Larrmore & SMITH: FISHES Or CHAMPAIGN COUNTY 341 Table 14.—Average number of species per station and average number and weight of fish taken per 100 square yards in 1928 and 1959 at 71 stations (not noticeably affected by pollution) classified by size of drainage basin; also, average number of pounds of fish per 100 square yards in 1959. AVERAGE NUMBER OF SPECIES AVERAGE NUMBER OF FISH PER STATION PER 100 SQUARE YARDS AVERAGE STREAM : a NUMBER OF SIZE ee ve POUNDS OF (Square | NUMBER 1959 FISH PER MILES OF me Ee Ratio RATIO 00 SQUARE Drain- | STATIONS) Gottec- | Quanti-| Total | 1928: 1959| 1928 | 1959 | 1928: 1959 es aano AGE) * fon tative Collec- Sample] tion lat 2 3.0 7.5 8.5 2.8 126 | 1700 1:13.4 2.9 sn ees 4 10.2 10.5 mes Gia 676 617 1: 0.9 2.8 8-16 - 13 9.5 12:2 1335: 131.4 462 718 116 2.2 16-32 10 13.3 15.6 16.2 ANZ 539 704 Utes Pal 32-64 | 17 ey 15.9 Lo 15 a5) 397 367 O29 Zell 64-128 5 14.0 21.0 21.8 1:16 345 440 ese 3.7 128-256 10 20.0 26.1 28.3 US es 309 oi Ie (003) Slefl 256-512 _.. 10 LIES 22.8 PAT) ea 157 80 M055 a) *Classification used by Thompson & Hunt (1930). In our work, we considered the numerals as designating size limits, so that a stream classified as size 4-8 had a drainage area of moze than 4 and not more than 8 square miles. units of stream size treated by Thompson Number of Species and Stream & Hunt; hence, our first point represents Size-—The number of species of fishes stations having 2-8 square miles of drain- per collection increases downstream. This age, not 0.5—4 miles as in the treatment hypothesis of Thompson & Hunt was sup- by Thompson & Hunt. ported by our collections in 1959. Our Number of Stations Represented |«——_ 6 |¢—_ |3—» |< 10> |< |7—> | +>—_____ 25 ——_> | 26 w wD 5 SS o 22 36 =| 5 ea = (op) ® 8 18 = © © a (oie % o = iL oO 14 | f. 344 ILtinois NaTuRAL History SurvEY BULLETIN Vol. 28, Art. 2 habitat succession and in degree of hu- ty streams in which they were present. — man-induced modification, most fish spe- However, some support for the Thomp- — cies showing definite patterns of distribu- son & Hunt concept expressed above was — tion based on stream size did not exhibit found. The following species showed : these patterns in all the Champaign Coun- somewhat consistent distribution patterns Table 19.—Other minnows and the carp. Average numbers of each of several species taken in the 1959 survey (quantitative samples only) in streams of various size ranges. Each species average is for only those stream systems in which the species occurred in the quantitative col- — lections. " DRAINAGE AREA OF STREAM IN SQUARE MILES AT i S PoINT OF COLLECTION 5 PECIES 2 ; P 4 2-4-8 1632-64 128 256512 ; Semotilus atromaculatus — 250.0 263.8 130.9 55.2 56.1 31.3 4.3 8.1 a Phenacobius mirabilis 0.6 1.1 5.2 1.3 1.0 1.5 0.4 1 Ericymba buccata . 11.1 67.2 8.9 38.0 29.8 1.5 0.4 | Hybopsis biguttata* 20.8 0.5 52.0 23.3 6.5 9.0 0.7 1.4 a Notemigonus crysoleucas a 0.2 tr. 0.3 0.8 ES 0.5 Cyprinus carpio. aS 0.2 4.3 3.8 1.0 0.3 5 *All streams except Embarrass. : F 2 Table 20.—Catfishes. Average numbers of each of several species taken in the 1959 survey — (quantitative samples only) in streams of various size ranges. Each species average is for only — those stream systems in which the species occurred in the quantitative collections. * DRAINAGE AREA OF STREAM IN SQUARE MILES AT POINT Or COLLECTION SPECIES ‘ oo ] ae) Ar nsss, SS, Yaa, OM (7 ENNIS Ictalurus natalis_.. 4.3 i 0.4 0.9 0.5 0.2 0.1 0.1 Noturus gyrinus*___ ee ae 0.1 0.3 I 0.2 tr. 0.1 Woturus flavnst 33> os, es 1g ae 0.1 0.1 0.1 0.6 0.2 Noturus miurust — : i ae zane at 0.1 12 ee " Ictalurus punctatust aa Se ie a : che 0.3 0.3 Pylodictus olivaris§ — 0.1 . @§ re *Salt Fork, Sangamon, and Kaskaskia only. tMiddle Fo:k and Embarrass only. ea {Salt Fork, Middle Fork, and Sangamon only. §Middle Fork only. Table 21.—Sunfish and bass. Average numbers of each of several species taken in the 1959 survey (quantitative samples only) in streams of various size ranges. Each species average is for only those stream systems in which the species occurred in the quantitative collections. DRAINAGE AREA OF STREAM IN SQUARE MILES AT Point OF COLLECTION SPECIES 2h ee Lepomis megalotis za 1.5 0.3 0.2 0.7 0.6 0.8 0.2 Micropterus dolomieui* _ bo: 3.2 0.8 2 1.3 0.3 1.3 0.2 Micropterus punctulatust eh 8.2 be aly ae sted 7.0 ae Lepomis macrochirust—— hay tr. 0.1 nex 0.2 0.1 tr. Lepomis cyanellus _.. 5.0 vas: 0.2 0.6 1.2 2.8 2.0 1.3 Ambloplites rupestris* r Pet ae 0.4 eo ae 0.6 0.3 Micropterus EEE é So 0.1 0.2 Pomoxis annularis* 0.1 {0 Lepomis humilist 0.9 *Salt Fork, Middle Fork, and Sangamon oniy. ¢Salt Fork, Kaskaskia, and Sangamon only. {Middle Fork only. §Salt Fork and Sangamon only. March, 1963 in relation to stream size in at least three of five drainage systems in the county: Catostomus commersoni Erimyzon oblongus Hypentelium nigricans Cyprinus carpio Ericymba buccata Ictalurus natalis Lepomis cyanellus Etheostoma spectabile Because of great variation in habitat succession among Champaign County streams, we might suppose that the species showing some consistency in distribution pattern in relation to stream size were those adapted to a wide variety of habitat conditions or to a set of conditions closely related to stream size. The following spe- cies apparently were not adapted to these conditions, for their distribution patterns showed no consistency from stream to Larimore & SmItTH: FISHES OF CHAMPAIGN COUNTY 345 stream and little correlation with stream or drainage size: Notropis chrysocephalus Notropis stramineus Notropis umbratilis Noturus gyrinus Lepomis megalotis Etheostoma blennioides Etheostoma nigrum Percina maculata Thompson & Hunt suggested that the place of greatest abundance of a species might be related to a specific stream size. In 1959, each species listed below was taken in greatest abundance in a spe- cific stream size in each drainage: Moxostoma erythrurum Campostoma anomalum Hybopsis biguttata Notropis spilopterus Semotilus atromaculatus Table 22.—Darters. Average numbers of each of severa! species taken in the 1959 survey (quantitative samples only) in streams of various size ranges. Each species average is for only those stream systems in which the species occurred in the quantitative collections. DRAINAGE AREA OF STREAM IN SQUARE MILES AT PoINT OF COLLECTION SPECIES jae LE Sf ae ah 2128 ==- 956512 Etheostoma nigrum le Deed) 3.9 26.9 6.5 10.4 3.9 Das Etheostoma spectabile —__ 38.0 6.8 9.3 44.9 8.9 0.2 0.4 0.2 Wencinag maculata = 4.1 0.1 0.5 0.7 0.4 0.8 0.4 Etheostoma flabellare* 36 0.5 3.6 0.5 tr. 0.1 Etheostoma caeruleumt___ 0.4 0.4 0.2 a 0.1 cae Etheostoma blennioidest —- 0.8 “ 0.2 0.1 0.9 0.1 Percina caprodes§ 0.1 0.1 Mae 0.1 Percina phoxocephala\ tr. 0.7 0.3 Etheostoma zonale|| fie 0.2 *Salt Fork, Middle Fork, and Sangamon only. TAIL streams except Sangamon. Salt Fork, Middle Fork, and Embarrass only. §Kaskaskia, Sangamon, and Embarrass only. {Sangamon and Middle Fork only. ||Sangamon only. Table 23.—Miscellaneous fishes. Average numbers of each of several species taken in the 1959 survey (quantitative samples only) in streams of various size ranges. Each species average is for only those stream systems in which the species occurred in the quantitative collections. DRAINAGE AREA OF STREAM IN SQUARE MILES AT PoINT OF COLLECTION SPECIES ES : ES, res | ah | Seeeey (Rees |) meee, LY ees Ir) Fundulus notatus* 21.4 4.9 0.9 0.8 0.1 0.1 Abphredoderus sayanust 0.5 tr. tr. 0.2 zd tr. Esox americanust 0.2 0.2 0.5 0.2 we Dorosoma cepedianum§ : bs ft zee 0.3 ce 0.3 2.0 Labidesthes. sicculus§ = = ebe ak md meh tr. *All streams except Middle Fork. 7Sangamon, Embarrass, and Kaskaskia only. tEmbarrass, Kaskaskia, and Middie Fork only. §Sangamon only. QSalt Fork only. 346 Other hypotheses by Thompson & Hunt suggest that in certain species the entire population is confined to a certain stream size of very narrow limits. In the 1959 collections, none of the species (among those taken in sufficient numbers to sup- port such a conclusion) was confined to a certain stream size in more than two or three of the five county drainages con- sidered here. This lack of restricted dis- tribution was due probably to the lack of: restricted habitats; in streams of the sizes found in Champaign County, some habi- tats that are characteristic of large streams were found upstream and many habitats that are characteristic of small streams were found downstream. Even ecological factors most closely related to stream size, such as bottom materials and vegetation, were not restricted to a degree that was known to limit the distribution of any species. In both 1928 and 1959, young and adults of most species occurred abundantly in the same areas. However, the young of some of the suckers had their greatest fre- quency of occurrence upstream. The fol- lowing species (in addition to most of the suckers, with their well-known upstream movements to spawn in spring) showed proportionately greater numbers of small fish than large in the upstream areas: Campostoma anomalum Cyprinus carpio Hybognathus nuchalis Ictalurus natalis A mbloplites rupestris Lepomis macrochirus Micropterus dolomieut Micropterus punctulatus Conclusions on Relationships Information from the 1959 collections reinforced the hypotheses of Thompson & Hunt regarding the distribution of num- ber of species and number of individuals per unit area in relation to stream size, and it agreed moderately well with their theories regarding average size of fish and distribution of weight per unit area. Some of the other suggested relationships between the fishes and stream size appear less tenable, probably because of the great variation in habitat currently found in Champaign County streams. These re- lationships generally follow the ecological ILttrno1is NaturAL History SURVEY BULLETIN Vol. 28, Art. 2 succession of streams as illustrated by Shelford (1911) in his collections of fishes from creeks in the Chicago region. Shel- ford’s work and the studies of Champaign County fishes are based on the assumption that similar fish communities occupy sim- ilar physiographic stages in aging (base leveling) of a stream. Thompson & Hunt contributed several clear, practical expres- sions and interpretations of stream suc- cession, and their use of drainage area as an expression of stream size can be con- sidered a substantial contribution. The 1959 survey adds further to the knowledge of succession in warm-water streams. It provides data to substantiate many parts of the concept of succession, but at the same time offers an explanation for the many examples of failure of fish distribu- tion to fit the theoretical sequence of stream succession. The major reason for this failure is that base leveling does not often produce a perfect geologic succes- sion and a uniform progression of eco- logical factors. DISTRIBUTION AND POLLUTION Types of pollution have changed con- siderably during the years spanned by the three surveys of Champaign County fishes. Organic pollution, which began even be- fore the period of the backyard privy, has existed to the present time with its mod- ern scientific treatment of domestic wastes. Sources of chemical pollution have appeared; some of these have disappeared while others continue to threaten aquatic life. Pollution becomes most severe in areas of dense population and industrial development; thus, in Champaign Coun- ty, it is most severe in the region of Champaign-Urbana, which serves as the focus of the present study. (The State of Illinois Sanitary Water Board in 1951 defined pollution to include alteration of the physical, chemical, and __ biological properties of any waters to render them harmful to fish or other aquatic organisms. This definition, which would include the effects of temperature change, sediments, and abnormal chemical levels in effluents, will be followed here.) At the time Forbes & Richardson made their collections in the West Branch, around 1899, untreated organic wastes espinal March, 1963 from Champaign and Urbana were car- ried by two gravity-flow sewers that dis- charged directly into the lower Boneyard creek and into the nearby West Branch proper. There was some additional pol- lution from stables, the power plant, and a few small industries, but the collections of Forbes & Richardson indicate that the fish population in the West Branch had not been seriously affected, as a variety of species, similar to that which might be found in nearby streams unaffected by pollution, was present, table 24. A vivid description of conditions in the Boneyard and the West Branch of the Salt Fork for about two decades fol- lowing the work of Forbes & Richardson was given by Baker (1922:170-85). By Larimore & SMITH: FisHEs oF CHAMPAIGN COUNTY 347 1918, the Boneyard was apparently barren of clean-water organisms. The West Branch from Urbana to St. Joseph was laden with masses of decomposing matter made up of foul-water algae and protozoa, and its bottom was inhabited by slime worms. Even below the junction of the West Branch and the East Branch, con- ditions were septic, and clean-water life did not appear for a distance of several miles downstream. In 1917, legislation permitted the or- ganization of the Urbana-Champaign San- itary District with the result that, by 1924, the sewage from both cities passed through a disposal plant. Although the disposal plant served to improve conditions in the West Branch, a high level of pol- Table 24.—Numbers of collections in which each of 22 species was taken in three sections of the West Branch and below by Forbes & Richardson (FR), Thompson & Hunt (TH), and Larimore & Smith (LS). No species not taken by Larimore & Smith is included. Figures in parentheses below FR, TH, and LS indicate numbers of collections made, except that they do not include collections made by Thompson & Hunt or Larimore & Smith subsequent to their initial visits. Species taken in the subsequent visits and at no other time are indicated by +. In THE 4 MILEs In THE 9 MILES feet 1 ABOVE SEWAGE BELOW SEWAGE Wins eines DisposAL PLANT DisposAL PLANT B SPECIES RANCHES FR TH LS FR TH LS FR TH LS (3) (4) (4) (4) (4) (4) (3) (2) (2) Bcekaehiube ees le ei Pe 0 4 4+ 1 2 2 3 2 2 SeGnMmSUMfISh 2 Z 4 3 4 als 1 0 0 2 |. TPS. 5 ee Cet 0 0 3 0 0 1 0 0 Z Sroldenushinen se 7 2 4 2 3 2 at 1 2 2 Bluntnose minnow. 3 3 3 3 2 ar 2 2 2 einineshiner =. «283 Fe 0 3 3 0 3 air 0 1 1 (Common shiner... 0 0 3 2 0 eli 0 0 2 Brimmcysnine nt. 0 0 2 4 0 lg 0 1 0 Mihiteasncker 2 1 2 Z 2 0 aI 1 1 1 Brrrivennilenees res ol Sy . 1 3 3 2 0 ate 0 1 0 Silverjaw minnow... 2 3 2 1 1 an 0 2 0 Creek chubsucker_ 3 2 3 3 0 0 0 1 1 ppothin shiner*.. 2 3 0 te 3 1 =f 0 1 2 Yellow bullhead ee te oe 1 1 1 0 0 0 0 0 1 Hobony darter... 1 3 2 3 0 0 3 1 0 Moncear sunfish... 2 4 1 4 0 ale 1 1 0 fetass pickerel Pe: 1 2 0 2 0 0 1 0 1 Golden redhorse_ 1 0 0 2 0 0 0 0 1 Praia kes * el tT 0 0 0 1 0 0 0 0 1 Lu SCI ca eI ae 1 1 0 0 0 ae 0 0 0 Meeeecrappie 1 0 0 1 0 + 1 0 0 Hormyhead chub... 0 0 ar 1 0 0 0 0 0 Number of species taken in first collections... 23 20 15 33 6 3 20 19 14 Number of species taken in subsequent collections __ _ 2 So 1 12 a, a en *Presumed to represent only this species at these stations, although name used in early surveys was known to be a composite of two or more species. 348 lution still existed, and very few fishes were found there by Thompson & Hunt when they made their collections in 1928. improvements in the efficiency of the san- itary system were made at frequent inter- vals between 1928 and 1959, and at pres- ent most of the Champaign and Urbana wastes are given complete treatment. In recent years, Rantoul, Gibson City, and the Chanute Air Force Base have in- stalled sewage treatment plants. Although, in the past 60 years, Cham- ) paign County has lost such sources of pollutants as the early gas plants and stables, and has improved the sewer sys- tems and the treatment of human waste, it still has to contend with domestic sew- age from outlets illegally connected to storm sewers; chemicals that pass un- changed through the treatment plant; oils that wash from roads and machinery; wastes from canning plants, milk plants, and soybean mills; modified water tem- peratures; and agricultural chemicals, such as modern herbicides and _insecti- cides. It has the University of Illinois chemical laboratories, the Chanute Air Force Base machinery, and an ever-in- creasing number of industries. Along with these pollutants, there is the growing problem of an increasing vol- ume of effluents, which may be detri- mental to aquatic life, no matter how well they have been treated. The Champaign- Urbana community and the West Branch provide a good example. In October, 1917, a total flow of 3,000,000 gallons per day was reported for the Salt Fork below the disposal plant (Baker 1922:171). About half of this volume (1,500,000 gallons per day) was from the sanitary treatment plant. The natural stream flow was low when the measurement was made and is comparable to that during the low water period of September, 1959, when we studied the West Branch. In September, 1959, the total volume of sewage going through the plant was 7,276,000 gallons per day, nearly five times the volume cited by Baker for 1917. (This and similar 1959 figures are from a monthly report of the Urbana-Champaign Sanitary District.) If the natural volume of the flow in the West Branch has not changed over these years, and the sewage effluent has increased nearly five-fold, the I~ttino1s Natura History SurvEY BULLETIN Vol. 28, Art. 2 West Branch below the disposal plant must be nearly three times as large as it was in 1917. The total flow has changed from one-half effluent in 1917 to four- fifths eluent in 1959. In September, 1959, this efHuent had a biochemical oxygen de- mand of 9 p.p.m., which would quickly reduce the oxygen in the natural stream water with which it was mixed; natural agitation of the owing waters would, of course, partially replace the dissolved ox- ygen used up by the effluent material. In spite of the present high level of efficiency for the treatment plant, which produces an efHuent that is as nearly perfect as sanitary engineers consider practical, the stream remains unfit for most aquatic life. The problem centers on the great volume of efHuent that is produced and on the accumulation of chemical agents that pre- clude existence of clean-water organisms. Areas of Chronic Pollution Seven principal areas of chronic pollu- tion, fig. 14, affect the distribution of Champaign County fishes, figs. 15-70. The Boneyard.— Because of its loca- tion in the center of Champaign-Urbana, fig. 14, the Boneyard receives quantities of varied pollutants. Although Forbes & Richardson collected Johnny darters from the stream, some pollution probably existed then. According to Baker (1922:172), at the time of his study the Boneyard was receiving domestic pollutants as well as oil and tar from the gas works; pollution — was extremely severe ‘in 1915. Thompson & Hunt stated that the Boneyard con- tained no permanent fish population in — 1928, although at that time, as well as in 1959, some fishes occasionally moved into — polluted areas during high water and re-— mained for short periods. In 1958, black bullheads taken from the Market Street gutters during a period of high water were collected by several peo- — ple and identified by Dr. Marcus S. Gold- man. Apparently the fish had moved up — the Boneyard, through the storm sewers, — and out through the street drains. Except for similar brief ingressions, no fish occur at the present time in the Boneyard. It remains badly polluted by waste from im- properly connected household drains and — from businesses discharging directly into~ the ditch or into storm drains. March, 1963 West Branch. — Although Forbes & Richardson found a variety of fishes in the West Branch of the Salt Fork during their survey, this creek has subsequently undergone drastic reduction in both va- Larimore & SmITH: FISHES OF CHAMPAIGN COUNTY 349 riety of species and abundance of indi- viduals. The West Branch is divisible into three sections: Section 1, the 4+ miles of creek above the Urbana-Champaign disposal plant; Section 2, the creek from —— SR C) MIDDLE ~ A X / Og ‘ : ©) VA ee 4 7 es ST 4 ee ve ‘e / 4 / sr is My 5 {] - D/ yy) “ = = l y ere FEE Severe pollution ee / y ; EE] Moderate pollution a f q 5 ieee she DRS Modified water temperature © Chemical sampling station wy. © O ©) O Fig. 14.—Distribution of pollution in Champaign County and location of seven stations at which chemical analyses were made in 1960. Severe pollution was found in Copper Slough and Phinney Branch west of Champaign-Urbana (city near center of map), the Boneyard in Champaign-Urbana; the West Branch of the Salt Fork east of Champaign-Urbana, the East Branch of the Salt Fork east of Rantoul (upper center of map), and the small stream from Chanute Field south of Rantoul. 350 Ittinois NATURAL History SURVEY BULLETIN the disposal plant to its junction with the East Branch; and Section 3, the stream (actually the Salt Fork) from the junc- tion of the East and West branches down- stream for a distance of 4 miles. Section 1 presumably was relatively free of pollution when Forbes & Richard- son collected at least 23 species there. In 1928, Thompson & Hunt described this section as clean and relatively free of pol- lution; they reported 20 species in the area. Since 1928, however, waste water from the northward expansion of Urbana and from several industrial plants has Vol. 28, Art. 2 polluted this portion of the stream. In 1959, only 15 species of fish were found there, table 24. Examples of species that disappeared early from this section were the spotted sucker, golden redhorse, suckermouth min- now, black bullhead, black crappie, and — two species of darters. Species that disap- peared in recent years (as pollution in- creased) were the grass pickerel, tadpole madtom, brook silverside, and bluegill. — The most notable examples of species ap- _ pearing in the section for the first time after 1900 were the carp, common shiner, Table 25.—Number of fish per 100 square yards and number of species taken at sampling stations above and below sewage disposal plant on the West Branch of the Salt Fork by Thomp- son & Hunt and by Larimore & Smith. Presence of a species in very small numbers is indi- cated by +. THOMPSON & HUNT STATION IN RELATION TO DISPOSAL PLANT Number of Fish per 100 Square Yards LARIMORE & SMITH 7 miles above 150 AS milessaDOVe na 167 timile-abpove see see aS 67 mile above. - 332 114 miles below... 2 2% miles below... 14 4 miles below__...........---- 7 614 miles below... 30 12 miles below 2. 397 Number of Number of Fish per 100 Number of Species Square Yards Species 10 510 6 10 230 1 11 675 10 11 37 9 Z 0 0 3 aE 1 2 1 2 + a 1 15 9 12 Table 26.—Number and weight (pounds) of fish per 100 square yards, and average number of species per station, collected in 1959 at various stations in two streams, one polluted (part of West Branch and Salt Fork) and one unpolluted (part of East Branch'and Salt Fork). Each station is located with reference to stream size. POLLUTED AREA UNPOLLUTED AREA Collection per Collection per — STREAM SIZE Number 100 Square Number 100 Square (Square MILES] Number ot Yards Number of Yards OF ae of Species f p Ys P ~ Be Empannas® ee —Urre VERMMio, “or” x ian ee Fig. 25.—Campostoma anomalum. Fig. 26.—Cyprinus carpio. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. —— ee ee re March, 1963 LarimMoreE & SmitH: FISHES OF CHAMPAIGN COUNTY 365 soe OF YS le Ow a Ne eee sy I Lirrie VERN, ce VERMIC Se oN y~ °) ° 3; eEwaanaasel | / Y } y 1 eRMi ON Fig. 29—Hybopsis biguttata. Fig. 30.—Notemigonus crysoleucas. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. 366 ItLtino1is NarurAL History SURVEY BULLETIN Vol. 28, Art. 2 - ie Ewpanras> jp Za - oe Lorrie VERN oy re) Fig. 31.—Notropis chrysocephalus. wy 9 MiooLe LL onx | \ ~ “> y Ry Sa oF pe ay “LY ~~ 8 ‘B----3 Fig. 33.—Notropis lutrensis. Fig. 34.—Notropis rubellus. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. ‘a Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, cc lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. ; Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi cated species. Most of these stations had previously been sampled by Thompson & Hunt. — a March, 1963 Larimore & SMITH: FISHES OF CHAMPAIGN COUNTY 367 -- J ecg a 3 —tirrie VERMio, “oT / / ERMIL oy AT ON Fig. 37.—Notropis umbratilis. Fig. 38.—Notropis whipplei. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. 368 Intinors NarurAL History SurveY BULLETIN Vol. 28, Art. 2 } cunannste ' fy Fe) Oo, o N heeerce ( i ~~ berrce VEAM io, \ - ef ee / . a, \ Toe ‘ ie ! ] ) i | } ed va f Us > ; \ ~ ~~ : ~ / a —— Fig. 39.—Phenacobius mirabilis. s »~ mearRas? ra EX \ t ¢ Agen ea pees ot C 4 ee sane f —— é i : ) 4 ‘ ee < ERMC, 3 Oy or” Lire ed Fig. 41—Pimephales promelas. Fig. 42.—Semotilus atromaculatus. Distribution of Champaign County fishes as determined by three surveys at approximately 30-— year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson > & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. March, 1963 Larimore & SMITH: FISHES OF CHAMPAIGN COUNTY 369 nee fe, MIDDLE "4 5 JE Yoayy Fig. 44.—IJctalurus natalis. g ee Litre VERMMioy | Ewpannas® Fig. 45.—Ictalurus punctatus. Fig. 46.—Noturus flavus. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. t 370 Ittinors NATURAL History SuRvVEY BULLETIN Vol. 28, Art. 2 . : 3 OE CX LY 34 “4 : | ; * eel \ fe) SX 7a) SG ( = g =) r = : \ys “t oO 4 2) a ty f =) a ‘ : cD q + FORK re & (e. 5 » DS? UT. 3 a pes 4 ere Btliy x ; (err stp tiioy 3 fe) “ | Fins ) 12 De Aa 4 = Hf poe ss Oo SE / & BS | ot by pase 4 | . . . . v= Fig. 47.—Noturus gyrinus. Fig. 48.—Noturus miurus. 7 it] i o a ny ae 3 MIDDLE 4 os OR} rs : <= Oo L %e ll \ ae / Bb ~ SSS / M 4 “a NS Z b t see | i ro MIDDLE ~~FoR, ———— EMBARRAS™ j \ Ae Seat 'Z Sow) vy ¢ BUI ing SS A= Sie e VERMIL, Ss o)) Sess ~ ~O { \ ( ne _ } 1 \ = LT } J fe) ah E \ a \ s ee Bie O ‘e) 7 wt rahe = Fethtpraie VERMIC yo, BD ie \ i a Po ‘ i Hs fo) G ve ¥ / Q 2) / 0 , OO © Fig. 69.—Percina phoxocephala. Fig. 70.—A plodinotus grunniens. Distribution of Champaign County fishes as determined by three surveys at approximately 30- year intervals. Open triangle: collecting station of Forbes & Richardson; indicated species not collected. Solid triangle: collecting station of Forbes & Richardson; indicated species collected. Small open circle alone: collecting station of Thompson & Hunt and also, if extant in 1959, col- lecting station of Larimore & Smith; indicated species not collected at this station. Large open circle enclosing small open circle or solid circle: collecting station at which Thompson & Hunt took indicated species. Solid circle alone or within large circle: collecting station at which Larimore & Smith took indi- cated species. Most of these stations had previously been sampled by Thompson & Hunt. INDEX The scientific names of fishes indexed below include currently valid names, variant spell- ings, and synonymic names and combinations. Generic names, when they stand alone in the text, have not been indexed. Thus, Carpiodes spp. is not included in the index, but a text refer- ence to any one of the species of Carpiodes is included. For convenience in indexing, specific and subspecific names are given equal rank. Thus, the subspecies Notropis spilopterus hy psiso- matus is indexed as Notropis hypsisomatus and hypsisomatus, Notropis, and the subspecies N. s. spilopterus as Notropis spilopterus and spilopterus, Notropis. The common names used are those recommended by the Committee on Names of Fishes, American Fisheries Society. Common names used in a generic sense in the text (basses, sunfishes, cathsh) have not been indexed. Common names for species have been indexed; common names for subspecies have not been indexed, as subspecies do not have officially recommended common names. Scientific names other than those of fish have not been inverted; for example, Rorippa islandica is listed but not islandica, Rorippa. A Abramis crysoleucas, 323 aestivalis, Hybopsis, 320, 322, 328, 329, 330, 332, 333 affinis, Gambusia, 325, 327, 330 Agricultural practices, 306, 307; see also Draining (drainage), Dredging Algae (algal blooms), 315, 347, 353, 354 alosoides, Hiodon, 321, 329 Ambloplites rupestris, 325, 329, 332, 333, 336, 344, 346, 371 amblops, Hybopsis, 322, 327, 328, 330, 332, 333 Ameiurus melas, 324 natalis, 324 American eel, 325 American elm, 313 americanus, Esox, 321, 327, 328, 332, 333, 336, 337, 345, 362 Amia calva, 321, 327, 330 Ammocrypta pellucida, 326, 329, 336, 337, 373 amnis, Notropis, 323, 329, 330, 333, 354 Anguilla chrysypa, 325 rostrata, 325, 329 anisurum, Moxostoma, 322, 329, 332, 336, 343 Annotated list of fishes, 320-7 annularis, Pomoxis, 326, 329, 336, 344, 373 anomalum, Campostoma, 322, 328, 332, 333, 335, 343, 345, 346, 364 A phredoderus sayanus, 325, 329, 336, 337, 345, 374 A plodinotus grunniens, 327, 329, 330, 336, 375 Asclepias incarnata, 313 asprigene, Etheostoma, 326, 329, 331 aspro, Hadropterus, 327 atherinoides, Notropis, 323, 328, 329, 331, 332 atripes, Notropis, 323 atrocaudalis, Notropis, 323 atromaculatus, Semotilus, 324, 327, 328, 330, 331, 332, 335, 344, 345, 368 auratus, Carassius, 322, 327, 330 aureolum, Moxostoma, 322 B Banded darter, 327 Bass largemouth, 326 rock, 325 smallmouth, 326 [ 376 | spotted, 326 yellow, 325, 357 Bigeye chub, 522 Bigeye shiner, 323 Bigmouth buttalo, 322 Bigmouth shiner, 323 higuttata, Hybopsis, 322, 328, 332, 333, 335, 338, 339, 344, 345, 365 Black buffalo, 322 Black bullhead, 324, 348, 350, 357 Black crappie, 326, 347, 350, 357 Blacknose shiner, 323 Blackside darter, 327 Blackstripe topminnow, 325, 352, 354 blennioides, Diplesion, 326 blennioides, Etheostoma, 326, 327, 329, 335, 336, 345, 373 blennius, Notropis, 323, 324, 329 Bluegill, 325, 347, 350, 357 Bluntnose darter, 326 Bluntnose minnow, 324, 347, 352, 353, 354, 357 Boleichthys fusiformis, 326 Boleosoma camurum, 326 nigrum, 326 Boneyard (creek), 309-10, 347, 348, 349, 351, 359 boops, Notropis, 323, 328, 330, 332, 333 Bowfin, 321, 357 breviceps, Moxostoma, 322 Brindled madtom, 324 Brook silverside, 325, 350 Brown bullhead, 324, 357 bubalus, Ictiobus, 322, 328, 329, 330, 332, 333 buccata, Ericymba, 322, 327, 328, 330, 335, 337, 338, 344, 345, 358, 365 ; Buffalo bigmouth, 322 black, 322 smallmouth, 322 Bullhead black, 324, 348, 350, 357 brown, 324, 357 4 yellow, 324, 347, 357 ‘ Bullhead minnow, 324 Buttonbush, 313 Cc cacruleum, Etheostoma, 326, 329, 335, 345 calva, Amia, 321, 327, 330 : March, 1963 Campostoma anomalum, 322, 328, 332, 333, 335, 343, 345, 346, 364 pullum, 322 camurum, Boleosoma, 326 camurum, Etheostoma, 320 canadense, Stizostedion, 320 caprodes, Percina, 327, 328, 329, 336, 345, 375 caprodes X semifasciata, Percina, 327 Carassius auratus, 322, 327, 330 Carex cristatella, 313 carinatum, Moxostoma, 320 arp. 516; 322, 344, 347, 350, 351, 352, 354, 357 carpio, Carpiodes, 320 carpio, Cyprinus, 322, 327, 328, 331, 332, 336, 344, 345, 346, 364 Car piodes car pio, 320 cyprinus, 321, 328, 330, 336, 343, 362 difformis, 321 hinei, 321 velifer, 321, 328, 330, 336, 343, 362 Carpsucker highfin, 321 quillback, 321 Catfish channel, 324, 357 flathead, 324 Catostomus commersoni, 321, 327, 328, 335, 338, 343, 345, 358, 363 nigricans, 321 cayuga, Notropis, 323 cepedianum, Dorosoma, 321, 328, 330, 336, 345, 362 Chaenobryttus gulosus, 325, 329, 332 Channel catfish, 324, 357 Chara sp., 313 Chemistry of polluted waters, 353; see also Water chemistry and Pollution (pollu- tants) chlorosomum, Etheostoma, 326, 329, 330, 332, 333 chrysocephalus, Notropis, 323, 328, 332, 333, 335, 338, 339, 343, 345, 358, 366 chrysypa, Anguilla, 325 Chub bigeye, 322 Greeks24, 336, 337, 347, 351, 352, 353, 354, 357 hornyhead, 322, 347, 351, 354, 357 silver, 322 speckled, 322 Chubsucker, creek, 321, 347, 352, 354 claviformis, Erimyzon, 321 Cliola vigilax, 324 coeruleum, Etheostoma, 326, 329 commersoni, Catostomus, 321, 327, 328, 335, 338, 343, 345, 358, 363 Common shiner, 323, 347, 350, 353, 354 Copper Slough, 349, 352, 356, 359 cornutus, Notropis, 323 Cottonwood, 313 Crappie black, 326, 347, 350, 357 white, 326, 357 Creek chub, 324, 336, 337, 347, 351, 352, 353, 354, 357 Creek chubsucker, 321, 347, 352, 354 crysoleucas, Abramis, 323 LarRimMore & SMITH: FISHES OF CHAMPAIGN COUNTY 377 crysoleucas, Notemigonus, 323, 327, 328, 336, 338, 344, 365 cyanellus, Lepomis, 325, 328, 329, 335, 336, 344, 345, 371 cyanocephalus, Notropis, 323 cyprinellus, Ictiobus, 322, 329, 330, 333 Cyprinus carpio, 322, 327, 328, 331, 332, 336, 344, 345, 346, 364 cyprinus, Carpiodes, 321, 328, 330, 336, 343, 362 D Darter banded, 327 blackside, 327 bluntnose, 326 dusky, 327 eastern sand, 326 fantail, 326 greenside, 326 Johnny, 326, 347, 348, 352, 354 mud, 326 orangethroat, 326 rainbow, 326 slenderhead, 327 slough, 326 Deciduous trees, 313 deliciosus, Notro pis, 323 Detergents, household, 353 Dianthera americana, 313 Diatom, 354 difformis, Carpiodes, 321 Diplesion blennioides, 326 Docks, 313 dolomieui, Micropterus, 326, 329, 330, 331, 332, 333, 336, 344, 346, 372 Dorosoma cepedianum, 321, 328, 330, 336, 345, 362 dorsalis, Notropis, 323, 327, 328, 331, 332, 335, 436,337, 338, 343, 358, 466 Drainage districts, 310, 311 Drainage systems (drainages), 300, 308, 317, S20 321) SS no 545) O57, 559, 559s ae Ce also names of streams Draining (drainage), 306, 307, 308, 310, 311, 317, 333, 358; see also Dredging, Drainage districts Dredging, 306, 310, 311, 313, 314, 315, 317, 320, 333, 358; see also Draining (drainage) Drum, freshwater, 327 duquesnei, Moxostoma, 322 Dusky darter, 327 E East Branch (of the Salt Fork of the Vermilion River), 311, 312, 314, 347, 349, 350, 351, 352, 353, 354, 355, 356, 359 Eastern sand darter, 326 Ecological associations, 335-9; see also Fish as- sociations Ecological characteristics (conditions, factors), 304, 311-3, 314, 336, 358 eel, American, 325 Electrofishing (electric seine, electric fish shock- er, rowboat shocker), 300, 302, 303, 304, 305, 308, 321, 322, 340; see also Methods, fish collecting (sampling) Elodea canadensis, 313 Embarrass River, 300, 301, 305, 306, 308, 312, 320, 321-6, 334-5, 338, 339-40, 342, 343, 378 Embarrass River—continued 344, 345, 349, 356, 358, 362-75 Emerald shiner, 323 emiliae, Opsopoeodus, 324, 328, 330, 332, 333 Equisetum arvense, 313 Ericymba buccata, 322, 327, 328, 330, 335, 337, 338, 344, 345, 358, 365 Erimyzon claviformis, 321 oblongus, 321, 327, 328, 335, 336, 338, 343, 345, 358, 363 sucetta, 321 erythrurum, Moxostoma, 322, 328, 336, 343, 345,. 364 Esox americanus, 321, 327, 328, 332, 333, 336, 337, 345, 362 vermiculatus, 321 Etheostoma asprigene, 326, 329, 331 blennioides, 326, 327, 329, 335, 336, 345, 373 caeruleum, 326, 329, 335, 345 camurum, 320 chlorosomum, 326, 329, 330, 332, 333 coeruleum, 326, 329 eulepis, 326 flabellare, 326, 329, 335, 345, 374 flabellare X lineolatum, 326 gracile, 326, 327, 329, 330, 333 jessiae, 326 lineolatum, 326 nigrum, 326, 328, 329, 336, 345, 374 spectabile, 326, 328, 329, 335, 345, 374 zonale, 327, 329, 336, 345, 374 Euglena Sanguinea, 354 sp., 354 eulepis, Etheostoma, 326 Eupatorium perfoliatum, 313 Eupomotis heros, 325 exilis, Noturus, 324, 327, 329, 330, 333 exilis, Schilbeodes, 324 F Fantail darter, 326 Fathead minnow, 324 Fertilizers, 307, 355; see also Water (stream) enrichment, Water (stream) fertility, Soil (soil types, soil materials) Fish abundance (weights, numbers) affected by pollution, 331 changes in, 299, 303, 339-41 number per 100 square yards, 339-42, 350, 351, 356, 358 in relation to stream size, 341-6, 358-9 species decreasing in, 330, 333, 349 species increasing in, 329, 330, 331, 333 species per station, 339-41, 350, 351, 358 weight per 100 square yards, 339-41, 350, 351, 355, 356, 358 Fish adaptations (changes), 331-5, 345 Fish, annotated list of, 320-7 Fish associations during low water, 339 with habitats, 335-7, 358 with other fishes, 335, 337-9, 358 Fish collecting methods; see Methods, fish col- lecting (sampling) Fish distribution (occurrence) changes in, 299, 303, 328-35, 358 Ituino1is NaturAL History SuRVEY BULLETIN Vol. 28, Art. 2 decreases in, 330, 332, 333, 335, 358 definition of, 331 distribution patterns, 327-8 increases in, 329-33, 335, 358 natural ranges of species, 327 in relation to discharge of stream, 310 in relation to pollution, 331, 346-55 in relation to restricted habitats, 335-7, 346 in relation to stream size, 340-6, 358-9 in relation to stream succession, 346 in relation to water enrichment, 352, 355-6 in relation to young, 346 species restricted to a single drainage, 334, 358 Fish kills (mortality), 352, 353-4, 355 Fish occurrence; see Fish distribution (occur- rence ) Fish species annotated list of, 320-7 composite, 299, 321, 329 extirpated, 333, 351 of hypothetical occurrence, 320 introduced, 324, 325, 327, 328, 329, 330, 357, 358 Fisheries (fishing, angling) commercialized sport, 321, 324, 357 fee-fishing, 357, 359 sport, 328, 356-7, 359 flabellare, Etheostoma, 326, 329, 335, 345, 374 flabellare X lineolatum, Etheostoma, 326 Flathead catfish, 324 flavus, Noturus, 324, 329, 332, 333, 336, 337, 344, 369 Freckled madtom, 324 Freshwater drum, 327 Fundulus notatus, 325, 328, 329, 335, 336, 345, 370 fusiformis, Boleichthys, 326 G Gambusia affinis, 325, 327, 330 Gar, longnose, 321 Garman’s sunfish, 325 gilberti, Notropis, 323. Gizzard shad, 321, 337, 357 Glaciation, 306 Golden redhorse, 322, 347, 350 Golden shiner, 323, 347, 354, 357 Goldeye, 321 Goldfish, 322, 357 gracile, Etheostoma, 326, 327, 329, 330, 333 Grass pickerel, 321, 347, 350 Grasses, 313, 315 Green sunfish, 325, 347, 354, 357 Greenside darter, 326 grunniens, A plodinotus, 327, 329, 330, 336, 375 gulosus, Chaenobryttus, 325, 329, 332 gyrinus, Noturus, 324, 329, 336, 344, 345, 370 gyrinus, Schilbeodes, 324 H Hadropterus aspro, 327 phoxocephalus, 327 Hantzschia amphioxus, 354 Herbs, 315 heros, Eupomotis, 325 heterolepis, Notropis, 323, 327, 328, 329, 330, 332, 333 March, 1963 Hibiscus militaris, 313 Highfin carpsucker, 321 hinei, Carpiodes, 321 Hiodon alosoides, 321, 329 tergisus, 321 Hog sucker, northern, 321 Hornyhead chub, 322, 347, 351, 354, 357 Human population, 306, 308, 317, 346, 357 humilis, Lepomis, 325, 329, 332, 336, 344, 371 Hybognathus nuchalis, 322, 328, 330, 336, 343, 346, 365 Hybopsis aestivalis, 320, 322, 328, 329, 330, 332, 333 amblops, 322, 327, 328, 330, 332, 333 biguttata, 322, 328, 332, 333, 335, 338, 339, 344, 345, 365 hyostoma, 322 hyostomus, 322, 328 kentuckiensis, 322 storeriana, 322, 328, 329 hyostoma, Hybopsis, 322 hyostomus, Hybopsis, 322, 328 Hypentelium nigricans, 321, 328, 331, 332, 333, 336, 338, 343, 345, 363 hypsisomatus, Notropis, 323 I Ictalurus melas, 324, 327, 328, 332, 335, 336, 369 natalis, 324, 327, 328, 335, 336, 344, 345, 346, 369 nebulosus, 324, 327, 330 punctatus, 324, 328, 344, 369 Ictiobus bubalus, 322, 328, 329, 330, 332, 333 cyprinellus, 322, 329, 330, 333 niger, 322, 329, 330, 333 urus, 322 illecebrosus, Notro pis, 323 Industrial development, 346, 358 Industrial wastes, 306 J jessiae, Etheostoma, 326 Johnny darter, 326, 347, 348, 352, 354 K Kaskaskia River, 300, 301, 305, 306, 308-10, 312, 315, 319, 320, 321-7, 330, 333, 334—5, 337, 338, 339, 340, 342, 343, 344, 349, 353, 354, 358, 359, 362-75 kentuckiensis, Hybopsis, 322 L Labidesthes sicculus, 325, 329, 332, 345, 370 Largemouth bass, 326 Lepisosteus osseus, 321, 330 Lepomis cyanellus, 325, 328, 329, 335, 336, 344, 345, 371 humilis, 325, 329, 332, 336, 344, 371 macrochirus, 325, 328, 329, 336, 344, 346, 372 megalotis, 325, 328, 329, 336, 344, 345, 372 microlophus, 325, 327, 330 miniatus, 325 pallidus, 325 punctatus, 325, 327, 329, 330, 333 Leptops olivaris, 324 lineolatum, Etheostoma, 326 Larimore & SmiITH: FISHES OF CHAMPAIGN COUNTY 379 Little Vermilion River, 300, 301, 305, 306, 308, 311, 321-7, 334—5, 339, 356, 362-75 Logperch, 327 Longear sunfish, 325, 347 Longnose gar, 321 lutrensis, Notropis, 323, 327, 330, 331, 332, 333, 336, 343, 366 Lycopus americanus, 313 Lysimachia nummularia, 313 M macrochirus, Lepomis, 325, 328, 329, 336, 344, 346, 372 macrolepidotum, Moxostoma, 322, 328, 330, 332, 336, 343, 364 maculata, Percina, 327, 329, 336, 345, 375 Madtom brindled, 324 freckled, 324 slender, 324 tadpole, 324, 350 megalops, Opsopaeodus, 328 megalotis, Lepomis, 325, 328, 329, 336, 344, 345, 372 melanops, Minytrema, 322, 328, 330, 332, 333, 363 melas, Ameiurus, 324 melas, Ictalurus, 324, 327, 328, 332, 335, 336, 369 Methods, fish collecting (sampling) , 299, 300-6 ; see also Electrofishing microlophus, Lepomis, 325, 327, 330 Micro pterus dolomieui, 326, 329, 330, 331, 332, 333, 336, 344, 346, 372 punctulatus, 326, 327, 329, 336, 344, 346, 372 salmoides, 326, 328, 329, 336, 344, 373 Middle Fork (of the Vermilion River), 300, 301, 305, 306, 308, 312, 313, 317, 320, 321-7, 334-5, 337, 338, 339-40, 342, 343, 349, 357, 358, 362-75 Milkweeds, 313 Mimic shiner, 324 miniatus, Lepomis, 325 Minnow bluntnose, 324, 347, 352, 353, 354, 357 bullhead, 324 fathead, 324 pugnose, 324 silverjaw, 322, 347, 352, 354 silvery, 322 suckermouth, 324, 350 Minytrema melanops, 322, 328, 330, 332, 333, 363 mirabilis, Phenacobius, 324, 328, 335, 336, 338, 344, 358, 368 mississippiensis, Roccus, 325, 327, 330 miurus, Noturus, 324, 327, 329, 336, 344, 370 miurus, Schilbeodes, 324 Mosgquitofish, western, 325 Moxostoma anisurum, 322, 329, 332, 336, 343 aureolum, 322 breviceps, 322 carinatum, 320 duquesnei, 322 erythrurum, 322, 328, 336, 343, 345, 364 macrolepidotum, 322, 328, 330, 332, 336, 343, 364 Mud darter, 326 380 ItLino1is NATuRAL History SuRVEY BULLETIN N natalis, Ameiurus, 324 natalis, Ictalurus, 324, 327, 328, 335, 336, 344, 345, 346, 369 nebulosus, Ictalurus, 324, 327, 330 niger, Ictiobus, 322, 329, 330, 333 nigricans, Catostomus, 321 nigricans, Hypentelium, 321, 328, 331, 332, 333, 336, 338, 343, 345, 363 nigromaculatus, Pomoxis, 326, 329, 332 nigrum, Boleosoma, 326 nigrum, Etheostoma, 326, 328, 329, 336, 345, 374 nocturnus, Noturus, 324, 327, 330 Northern hog sucker, 321 Northern redhorse, 322 notatus, Fundulus, 325, 328, 329, 335, 336, 345, 370 notatus, Pimephales, 324, 327, 328, 335, 336, 343, 368 Notemigonus crysoleucas, 323, 327, 328, 336, 338, 344, 365 Notropis amnis, 323, 329, 330, 333, 354 atherinoides, 323, 328, 329, 331, 332 atripes, 323 atrocaudalis, 323 blennius, 323, 324, 329 boops, 323, 328, 330, 332, 333 cayuga, 323 chrysocephalus, 323, 328, 332, 333, 335, 338, 339, 343, 345, 358, 366 cornutus, 323 cyanocephalus, 323 deliciosus, 323 dorsalis, 323, 327, 328, 331, 332, 335, 336, 337, 338, 343, 358, 366 gilberti, 323 heterolepis, 323, 327, 328, 329, 330, 332, 333 hypsisomatus, 323 illecebrosus, 323 lutrensis, 323, 327, 330, 331, 332, 333, 336, 343, 366 rubellus, 323, 327, 329, 331, 332, 336, 343, 366 spilopterus, 323, 327, 329, 335, 343, 345, 367 spilopterus X hypsisomatus, 323 stramineus, 323, 327, 329, 335, 343, 345, 367 umbratilis, 323, 327, 328, 331, 332, 336, 338, 343, 345, 367 volucellus, 324, 329 whipplei, 324, 329, 336, 343, 367 whipplii, 323, 324, 329 Noturus exilis, 324, 327, 329, 330, 333 flavus, 324, 329, 332, 333, 336, 337, 344, 369 gyrinus, 324, 329, 336, 344, 345, 370 miurus, 324, 327, 329, 336, 344, 370 nocturnus, 324, 327, 330 nuchalis, Hybognathus, 322, 328, 330, 336, 343, 346, 365 Nuphar advena, 313 O oblongus, Erimyzon, 321, 327, 328, 335, 336, 338, 343, 345, 358, 363 olivaris, Leptops, 324 olivaris, Pylodictis, 324, 329, 331, 332, 336, 344 Opsopaeodus megalops, 328 Opsopoeodus emiliae, 324, 328, 330, 332, 333 Vol. 28, Art. 2 Orangespotted sunfish, 325, 357 Orangethroat darter, 326 osseus, Lepisosteus, 321, 330 Oxbow (s), 311, 317 P Pallid shiner, 323 pallidus, Lepomis, 325 pellucida, Ammocrypfta, 326, 329, 336, 337, 373 Percina caprodes, 327, 328, 329, 336, 345, 375 caprodes X semifasciata, 327 maculata, 327, 329, 336, 345, 375 phoxocephala, 327, 329, 336, 345, 375 sciera, 327, 330 semifasciata, 327 perspicuus, Pimephales, 324 Phenacobius mirabilis, 324, 328, 335, 336, 338, 344, 358, 368 Phinney Branch, 349, 352, 356, 359 phoxocephala, Percina, 327, 329, 336, 345, 375 phoxocephalus, Hadropterus, 327 Phyla lanceolata, 313 Pickerel, grass, 321, 347, 350 Pimephales notatus, 324, 327, 328, 335, 336, 343, 368 perspicuus, 324 promelas, 324, 328, 336, 343, 368 vigilax, 324, 328, 330, 332, 333 Pirateperch, 325 Plankton (blooms), 354 ; Polluted waters, chemistry of, 353; see also Water chemistry, Pollution (pollutants) Pollution (pollutants) ; see also Water chem- istry, Water (stream) enrichment, Sewage, Fish distribution (occurrence), Fish abun- dance (weights, numbers) areas of chronic, 348, 353, 359 chemical, 346, 348 definition of, 346 domestic, 312, 346, 348, 352 fish tolerant of, 331, 351, 354-5 industrial, 312, 347, 348, 350, 352 organic, 346 types of, 346-8, 359 Pomoxis annularis, 326, 329, 336, 344, 373 nigromaculatus, 326, 329, 332 sparoides, 326 Pond(s), 317, 328, 356, 357, 359 Potamogeton foliosus, 313 spp., 313 Precipitation, 307, 310, 317 promelas, Pimephales, 324, 328, 336, 343, 368 Pugnose minnow, 324 pullum, Campostoma, 322 punctatus, Ictalurus, 324, 328, 344, 369 punctatus, Lepomis, 325, 327, 329, 330, 333 punctulatus, Micropterus, 326, 327, 329, 336, 344, 346, 372 ef Pylodictis olivaris, 324, 329, 331, 332, 336, 344 Quillback, 347, 352, 357 Quillback carpsucker, 321 R Ragweeds, 313 Rainbow darter, 326 March, 1963 Red shiner, 323 Redear sunfish, 325, 357 Redfin shiner, 323, 347, 351, 352, 354 Redhorse, golden, 322, 347, 350 Redhorse, northern, 322 Redhorse, silver, 322 Roccus mississippiensis, 325, 327, 330 Rock bass, 325 Rorippa islandica, 313 Rose mallow, 313 rostrata, Anguilla, 325, 329 Rosyface shiner, 323 rubellus, Notropis, 323, 327, 329, 331, 332, 336, 343, 366 Rumex altissimus, 313 rupestris, Ambloplites, 325, 329, 332, 333, 336, 344, 346, 371 S Salix interior, 313 salmoides, Micropterus, 326, 328, 329, 336, 344, 373 Salt Fork (of the Vermilion River), 300, 301, 305, 306, 308-10, 311, 312, 313, 317, 321-7, 334-5, 338, 339, 342, 343, 344, 345, 348, 349, 350, 351-2, 353, 354, 356, 357, 358, 359, 362-75 Sand darter, eastern, 326 Sand shiner, 323, 347, 352, 354 Sangamon River, frontis., 300, 301, 302, 303, 305, 306, 308-10, 312, 316, 317, 318, 320, S8Z1—/, 334, 335, 337, 338, 339; 342, 343, 344, 345, 349, 352, 353, 356, 357, 358, 359, 362-75 sayanus, A phredoderus, 325, 329, 336, 337, 345, 371 Schilbeodes exilis, 324 gyrinus, 324 miurus, 324 sciera, Percina, 327, 330 Sedges, 313 semifasciata, Percina, 327 Semotilus atromaculatus, 324, 327, 328, 330, 331, 332, 335, 344, 345, 368 Sewage, 306, 348, 352-3, 355-6; see also Pollu- tion (pollutants) Shad, gizzard, 321, 337, 357 Shiner bigeye, 323 bigmouth, 323 blacknose, 323 common, 323, 347, 350, 353, 354 emerald, 323 golden, 323, 347, 354, 357 mimic, 324 pallid, 323 red, 323 redfin, 323, 347, 351, 352, 354 rosyface, 323 sand, 323, 347, 352, 354 spotfin, 323, 347, 352, 354 steelcolor, 324 Shrubs, 315 sicculus, Labidesthes, 325, 329, 332, 345, 370 Silver chub, 322 Silver maple, 313 Silver redhorse, 322 Silverjaw minnow, 322, 347, 352, 354 Silverside, brook, 325, 350 Larimore & SMITH: FISHES OF CHAMPAIGN COUNTY 381 Silvery minnow, 322 Slender madtom, 324 Slenderhead darter, 327 Slough darter, 326 Smallmouth bass, 326 Smallmouth buffalo, 322 Soil erosion, 308 Soil (soil types, soil materials), 306, 313, 355, 359 Sparoides, Pomoxis, 326 Spartina pectinata, 313 Speckled chub, 322 spectabile, Etheostoma, 326, 328, 329, 335, 345, 374 spilopterus, Notropis, 323, 327, 329, 335, 343, 345, 367 spilopterus * hypsisomatus, Notropis, 323 Spoon River, 312, 313, 355 Spotfin shiner, 323, 347, 352, 354 Spotted bass, 326 Spotted sucker, 322, 350 Spotted sunfish, 325 Steelcolor shiner, 324 Stizostedion canadense, 320 Stonecat, 324 Stoneroller, 322, 347, 352, 354 storeriana, Hybopsis, 322, 328, 329 stramineus, Notropis, 323, 327, 329, 335, 343 ’ 345, 367 Stream discharge; see Water (stream) dis- charge Stream drainages; see names of streams, Drainage systems Stream gradient, 311, 313, 314, 315, 317 Stream (habitat) succession, 344—6 Stream habitats changes in, 317, 320, 333, 335, 358 classification and types of, 313-7, 358 ecological characteristics, 311-20 fish characteristic of various, 314, 335-7, 358 measurements of, 304, 336 Stream size expressed by size of drainage area, 345, 346 in relation to fish distribution, 340-6 in relation to fish size, 342, 358-9 in relation to fish weight (fish flesh), 342, 358-9 in relation to number of fish, 342, 358-9 in relation to number of fish species, 341-2, 358-9 Stream water, chemistry of; see Water chem- istry sucetta, Erimyzon, 321 Sucker northern hog, 321 spotted, 322, 350 white, 321, 347, 352, 354 Suckermouth minnow, 324, 350 Sunfish Garman’s, 325 green, 325, 347, 354, 357 longear, 325, 347 orangespotted, 325, 357 redear, 325, 357 spotted, 325 Sycamore, 313 Af Tadpole madtom, 324, 350 tergisus, Hiodon, 321 382 Topminnow, blackstripe, 325, 352, 354 Turbidity, 304, 312, 313, 317, 336 U umbratilis, Notropis, 323, 327, 328, 331, 332, 336, 338, 343, 345, 367 Urbanization, 308, 357; see also Human popu- lation urus, Ictiobus, 322 vy Vegetation ; see also specific names aquatic (stream), 304, 313, 315, 317, 320, 336,. 358 bank, 304, 312, 313, 336 overhanging, 304, 313, 317, 320, 358 velifer, Carpiodes, 321, 328, 330, 336, 343, 362 vermiculatus, Esox, 321 vigilax, Cliola, 324 vigilax, Pimephales, 324, 328, 330, 332, 333 volucellus, Notropis, 324, 329 WwW Warmouth, 325, 357 Water chemistry, 312, 353, 355; see also Pollu- tion (pollutants) and Polluted waters, chemistry of Water levels, 304, 307, 308, 311, 317, 328, 354 Water (stream) discharge, 308-10; see also Water (stream) flow (volume) ItLinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 2 Water (stream) enrichment, 355-6, 359; see also Pollution (pollutants), Water chem- istry, Sewage Water (stream) fertility, 355, 359; see also Water (stream) enrichment, Soil (soil types, soil materials) Water (stream) flow (volume), 315, 317, at 358; see also Water (stream) discharge Water temperature, 312, 317, 346, 353, 354 Water turbidity; see Turbidity Water velocity (current), 304, 312, 314, 317, 320, 336, 337 Water willow, 313 Weather, 307 West Branch (of the Salt Fork of the Ver- milion River), 309, 310, 312-3, 345-51, 353, 354, 359 Western mosquitofish, 325 whipplei, Notropis, 324, 329, 336, 343, 367 whipplii, Notropis, 323, 324, 329 White crappie, 326, 357 White sucker, 321, 347, 352, 354 Willows, 313 bg Yellow bass, 325, 357 Yellow bullhead, 324, 347, 357 Z zonale, Etheostoma, 327, 329, 336, 345, 374 Some Publications of the ILtiNois NaTuRAL History SURVEY © BULLETIN Volume 27, Article 2.—A Century of Biological Research. By Harlow B. Mills, George C. Decker, Herbert H. Ross, J. Cedric Carter, George W. Bennett, Thomas G. Scott, James S. Ayars, Ruth R. Warrick, and Bessie B. East. December, 1958. 150 pp., 2 frontis., illus., bibliog. $1.00. Volume 27, Article 3.—Lead Poisoning as a Mortality Factor in Waterfowl Populations. By Frank C. Bellrose. May, 1959. 54 pp., frontis., 9 figs., bibliog. 50 cents. Volume 27, Article 4.—Food Habits of Migra- tory Ducks in Illinois. By Harry G. Ander- son. August, 1959. 56 pp., frontis., 18 figs., bibliog. 50 cents. Volume 27, Article 5.—Hook-and-Line Catch in Fertilized and Unfertilized Ponds. By Donald F. Hansen, George W. Bennett, Robert J. Webb, and John M. Lewis. August, 1960. 46 pp., frontis., 11 figs., bibliog. Single copies free to Tilincis residents; 25 cents to others. Volume 27, 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. bibliog. $1.00. (Make check payable to University of Illi- nois; mail check and order to Room 279, Nat- ural Resources Building, Urbana, Illinois:) Volume 28, Article 1.—The Amphibians and Reptiles of Illinois. By Philip W. Smith. November, 1961. 298 pp., frontis., 252 figs., bibliog., index. $3.00. CIRCULAR 39.—How to Collect and Preserve Insects. By H. H. Ross. July, 1962. (Sixth printing, with alterations.) 71 pp., frontis., 79 figs. Single copies free to Illinois residents; 25 cents to others. 47.—Illinois Trees and Shrubs: Their Insect Enemies. By L. L. English. March, 1962. (Second printing, with revisions.) 92 pp., frontis., 59 figs., index. Single copies free to Illinois residents; 25 cents to others. 48.—Diseases of Wheat, Oats, Barley, and Rye. By G. H. Boewe. June, 1960. 159 pp., frontis., 56 figs. Single copies free to Illinois resi- dents; 25 cents to others. List of available publications mailed on request. Single copies of ILt1vois NATURAL History Survey publications for which no price is BIOLOGICAL NOTES __ 37.—Continuous Mass Rearing of the | pean Corn Borer in the Laboratory, Paul Surany. May, 1957. 12 pp., 7 figs. 38.—Ectoparasites of the Cottontail Rabbit Lee County, Northern Illinois. By Stannard, Jr., and Lysle R. Pietsch. — 1958. 20 pp., 14 figs., bibliog. 39.—A Guide to Aging of Pheasant Embry By Ronald F. Labisky and James F. © September, 1958. 4 pp., illus., bibliog. - 40.—Night-Lighting: A Technique for C turing Birds and Mammals. By Rona ¢ Labisky. July, 1959. 12 pp., 8 figs., b 41—Hawks and Owls: Population From Illinois Christmas Counts. By R R. Graber and Jack S. Golden. March, 1 24 pp., 24 figs., bibliog. f 42.—Winter Foods of the Bobwhite in Sou ] Illinois. By Edward J. Larimer. May, 0. 36 pp., 11 figs., bibliog. SO 43.—Hot-Water and Chemical Treatment ¢ of Illinois-Grown Gladiolus Cormels. By J. J. L Forsberg. March, 1961. 12 pp., 8 figs., liog. 44.—The Filmy Fern in Illinois. By Rob Evers. April, 1961. 15 pp., 13 figs., b 45.—Techniques for Determining Age coons. By Glen C. Sanderson. Augus 16 pp., 8 figs., bibliog. ‘ 46.—Hybridization Between Three Speci Sunfish (Lepomis). By William F. and George W. Bennett. November, 15 pp., 6 figs., bibliog. ‘ 47,—Distribution and Abundance of Phe: in Illinois. By Frederick Greeley, Ron Labisky, and Stuart H. Mann. March, 16 pp., 16 figs., bibliog. 48.—Systematic Insecticide Control of Pests of Trees and Shrubs—A Prelim Report. By L. L. English and Walter E stirn. August, 1962. 12 pp., 9 figs., biblia v7 a 49.—Characters of Age, Sex, and Sexual b turity in Canada Geese. By Harold C, F son. November, 1962. 15 pp., 13 figs, Di l MANUAL 4.—Fieldbook of Illinois Mammals. By D F. Hoffmeister and Carl O. Mohr, Jun 1957. 233 pp., color frontis., 119 figs., sary, bibliog., index. $1.75. =a will be furnished free of charge to individuals until the supply becomes low, after whic nominal charge may be made. More than one copy of any free publication may be obt | without cost by educational institutions and official organizations within the State of I prices to others on quantity orders of these publications will be quoted upon request. Address orders and correspondence to the Chief, ILtrNots Nat History Survey, Natural Resources Building, Urbana, Illinois: Payment in the form of money order or check made out to State Treasurer of - Springfield, Illinois, must accompany requests for those publications on which a price ILLINOIS NATURAL HISTORY SURVEY Bulletin Printed by Authority of (mg the State of Illinois pres A Comparative Study of Bird Populations in Illinois, 1906-1909 and 1956-1958 RICHARD R. GRABER JEAN W. GRABER STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION NATURAL HISTORY SURVEY DIVISION Urbana, Illinois Ritson) TLLINOIS NATURAL HISTORY SURVEY Bulletin Volume 28, Article 3 Printe Pe Authority of October, 1963 the State of Illinois A Comparative Study of Bird Populations in Illinois, 1906-1909 and 1956-1958 RICHARD R. GRABER JEAN W. GRABER STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION NATURAL HISTORY SURVEY DIVISION Urbana, Illinois | View of floodplain in Pope County, southern I!linois, 1907 and 1963. Upper picture taken from cliff 1 mile east of Brownfield, June 27, 1907, by Alfred O. Gross. Lower picture, same area as upper picture; taken May 19, 1963, by Jean W. Graber. Sev- eral of the cultivated fields of the upper picture have been filled in with forest. Tree growth conceals the railroad tracks visible in the foreground of the upper picture. reat OR” 62 EB Kat od View of wooded hills in Hardin County, Upper picture taken from the east edge of Shetl ower picture, same area as upper picture; taken May 19, 1963, by Richard R. southern Illinois, 1907 and 1963. erville, June 29, 1907, by Alfred O. Gross. Graber. This area shows fewer changes in a half century than most Illinois areas censused, Overgrazed Pasture has replaced cultivated fields shown in the upper picture. y Kk phN y ‘ ; ‘ 23 % \ aS ‘ , * *, a ; om 1s 4 we v i Z ty ‘ ia + A ‘: : a. ; : i q raat 3 i r ; 4 ‘ ae Fi ‘ . ‘ ; % 7 x 1 ‘ji \ Voor ( pees : ; ee ss ee ‘ , ’ p “3 a i _ ee ; } . i . ‘ s j 4 f ae a bi ¥ ; es Y ¢ a “> he, Jf, Landscape in Mason County, central Illinois, 1907 and 1963. Upper picture taken one-half mile east of Poplar City, May 2, 1907, by Alfred O. Gross. Similar sandy wasteland with cacti is still found in small areas in the vicinity of the Illinois River. Such areas, if undisturbed, eventually become stabilized by grass. ; taken May 14, 1963, by Richard R. Graber. Lower picture, same area as upper picture; Sand prairie develops in relatively undisturbed areas in the vicinity of the Illinois River, CONTENTS ST a 383 Mourning, Dovyets. foe30. 0. ves 469 Forbes-Gross Strip Census.......... 383 RSUCKOOSS hs cays Oe et ee 472 Evaluation of Strip Census.......... 389 Chimney: owvitt savin 2 25-4 shhesa os 472 WEATHER PATTERNS OF CENSUS YEARS. 393 Yellow-Shafted Flicker........... 473 Birp PopuLATIONS IN SUMMER Red-Bellied Woodpecker.......... 474 MTS ee se ok ewe ce 396 Red-Headed Woodpecker......... 474 Mornpelds (Summer) ..............397 Downy Woodpecker.............. 475 Soybean Fields (Summer)..........401 Fasten.) Rinebitd .:cek). sss. eee: 476 Plowed Fields (Summer)........... 401 Homed Lark. 12. ae ee oats 477 Oat Fields (Summer).............. 401 Barn ss wiallower s+ sided eetee 478 Myheat Fields (Summer)........... 407 Blue Jay. rere eee eee eee 479 Pastures (Summer) .............-. 408 Common COLON th cect eet eee 480 Ungrazed Grasslands (Summer)..... 412 Chickadees ap kar ie dapat 481 Fallow Fields (Summer)........... 413 Tufted Titmouse tn a ee eae let a 482 Mixed Hayfields (Summer)........ 414 Mockingbird ERIE Rnd Raw AY at 483 Clover Fields (Summer)........... 418 CaCI tye eva tae eee We eee 483 RRO ET ice ae ss) a laisis tosss pare dys 418 Brow), Wiinasmen co cote ae 484 (yg ECON ee 420 Robin ........ slays a ola, Miele Gundein, ah eyeed ce 485 feraita Fields (Summer)........... 421 Eastern Bile ted eyo ciae eee me ape 486 Marshland (Summer) ............. 422 Starling Sas tits Bik) team aes oe Secce: cae 486 Shrub-Grown Areas (Summer)..... 424 Yellowthroat: 08 ets nc toys ee 487 Sieiards (Summer) .o..2.......6% 429 House Sparrewyee.t vents ter 488 Forests (Summer) PA am ne see ae ty ee 430 Bobolink aKeiNe; eh(edle yaj.mis: sf «/sahawsitah Suerrok ete sutsers 489 Urban Residential Areas (Summer ) x 436 Meadowlarks Tonic. ORD RON men crate eOnoRuctce 489 Comparison ot Data for Summer Redwinged Blackbird Da oo tM aa ces o 490) “Lr Hes asityi ad Ol pee 437 Orchard: sOriole: + jook oe Ue ee 49] mumber of Birds) o....5..4...... 438 Common Grackle:.....\.....@. 2.0 492 Mumiber of Species..... ......2.- 439 Brown-Headed Cowbird.......... 492 Statewide Summer Populations...... 440 Cardingl (os. Ak astap faite eee 493 Birp PopULATIONS IN WINTER Indigo, Bumting sas. oso aee 494 OSTEO SI ly i 443 Dickerssel i setectech ek sno Rae 495 Poriclds -(Winter)............... 443 American (Goldfinch...) .j2): een 495 Soybean Stubble (Winter).......... 447 Savannal. Sparrows ook... seen. 496 Plowed Fields (Winter)............ 448 Grasshopper Sparrow............ 496 Small Grain Stubble Fields (Winter) .448 Vesper 'Spartowst sen caves eee 497 Mvheat Fields (Winter)............ 449 Liarke SpALrOWinds cobs iancomanieean 497 Serseures (Winter) 2... ..00.. 4000. 451 Slate-Colored: Junto... ss leno sn02 497 Fallow Fields (Winter)............ 452 Tree? Sparta. cn irs siae nee eon 498 eaynelds \(Winter).............5.. 452 Chipping: (Sparrows). lec. teas 498 Scop Areas (Winter)............. 452 Piel@uopanrow sf... 2st 2a pace oe 498 MMPS IV INFECT) 05. foc oe. a wiv as 453 DOM Oo Pat Owes bid ck aan, Oeemeces 499 Comparison of Data for Winter Bapland Wongspir.. . 6. ween kee 500 SEUSS Ao 8 | DISCUSSION «2655 AU hace eet ee OD mimmiper of Birds. :.....0....... 456 Events Previous to 1800 ...........501 Member Of Species. 2... 0.052.545. 456 Development of Managed Habitats. .502 Statewide Winter Populations....... 456 Specific Changes in Avifauna....... .503 MeeOUNT OF SPECIES...........-..... 458 Specialization in Managed Habitats. .504 Avifaunal Differences Between Population Density and Avifaunal RES rer es hoe co ek as ins 463 Miairietye oo cat Oa hacienda Be OU Annotated List of Common Species. .463 Population Changes and Latitude... .508 Brey VUNENTE 0 ee ae e's 464 ANGE LAENSIONS vsse.de cals ee ete ren 508 ied=datled (HMawk..... 52.0220... 464 Habitats and the Future of the MT NE MENANVKS +h coil ovcce os Fe ws 465 PAMUBANUIAA Thiet cata ea pti ee od 509 VEE eS ea ee 466 Man and‘the Avifauna.............515 UREN PA capi tie enue © oes hs 3 ABA MORPERAT URE! (LTBI yen: vemole anise shop mere 516 tril lOVatr: a5 6 Sty ciikce me are « AIR eM RULNENE At Peaks bi Got Rie Tans eaten eG This paper is printed by authority of the State of Illinois, IRS Ch, 127, Par, 58.12. It is a contribution from the Section of Wildlife Research of the Illinois Natural History Survey. Dr. Richard R. Graber is Wildlife Associate with that section. Dr. Jean W. Graber is Research Associate in Animal Science, University of Illinois. (74985 —6500—6-63) xg@SSD, 2 Landscape in Sangamon County, central Illinois, 1907 and 1962. Upper picture taken one-fourth mile north of Buffalo Hart, June 24, 19 , Gross. Cornfields have comprised the largest Illinois habitat for at least the past 100 years. Lower picture, same area as upper picture; taken August 2, 1962, by James S. Ayars. Soy- beans (left foreground) came into wide use after 1920 and by 1957 occupied about 5,000,000 acres of Illinois land. A Comparative Study of Bird Populations in Illinois, 1906-1909 and 1956-1958 On Aucusr 29, 1906, Alfred O. Gross and Howard A. Ray, working for the Illinois State Laboratory of Natural His- tory (a parent organization of the Illinois Natural History Survey) under the di- rection of Stephen A. Forbes, began a series of statewide, cross-country censuses of birds in Illinois. These censuses were continued at intervals until September, 1909, and the data collected were pub- lished in a series of papers (Forbes 1907, 1908, 1913; Forbes & Gross 1921, 1922, 1923) that provided a quantitative record of the Illinois bird populations of that period and a potential basis for evaluating the adjustment of bird populations to a changing environment. In 1956-1958, we conducted statewide censuses similar to those of the 1906-1909 survey. In this paper we present an analysis of our field data and compare these data with those from the first survey. For suggesting and encouraging this study we are indebted to Dr. Harlow B. Mills and Dr. Thomas G. Scott of the Illinois Natural History Survey. Mr. Ronald F. Labisky of the Survey provided data on pheasant populations in a study area near Sibley, Illinois. Mr. John Ames and Mr. Herbert Brucker, both of Sibley, permitted us to establish and use special study areas on their lands. Mr. John Hill, Urbana, checked some of our calculations. We are particularly grateful to Dr. Alfred O. Gross, Emeritus Professor of Biology at Bowdoin College, who pre- sented us with all of the original field notes, journals, and photographs made on the first series of strip censuses conducted in Illinois (1906-1909) and encouraged our follow-up study. Finally, we are in- debted to Mr. James S. Ayars of the IIli- nois Natural History Survey, who edited the manuscript. METHODS For an excellent review and discussion of measuring bird populations by various hGH ALR DR. (GRA BBR JCAL. WG Kea B ek methods, we refer the reader to Kendeigh (1944+). Here we need a brief summary of only the Forbes-Gross method, the strip census method used in the 1906-1909 and the 1956-1958 surveys. Forbes-Gross Strip Census The Forbes- Gross method of census- ing was described in essence by Forbes (1907:307), who stated that two ob- servers ‘‘were sent into the field under instructions to traverse the state in various directions, traveling always in straight lines and always thirty yards apart, and noting and recording the species, numbers, and exact situation of all birds flushed by them on a strip fifty yards in width, in- cluding also those crossing this strip within one hundred yards to their front. No at- tention is paid by them, for this purpose, to any other birds.” Forbes likened the census operation to ‘a gigantic sweep-net 150 feet wide and 300 feet deep, so drawn across the country day by day as to capture every bird which comes in its way;... Certain details of the method were subsequently modified in the field, but the census techniques used during most of the survey by Gross and Ray in 1906-1909 were close to those described by Forbes & Gross (1921:1-2). Our ultimate authority in determining the census technique actually used by the two observers in 1906-1909 has been the cor- respondence, journals, and original field notes of Dr. Alfred O. Gross. In open-field habitats (cornfields, soy- bean fields, and plowed ground), the two observers stayed 30 yards apart as they censused and counted all birds within or crossing a strip 50 yards in width in line with the observers and 100 yards to the front. In more dense habitats (orchards, forest, shrub-grown areas, and hayfields), the observers maintained a distance of 20 yards between them and censused a 30- yard strip. They traveled at the rate of about 40-50 minutes per mile. [| 383 | eS as IP vi : = Fig. 1.—Alfred O. Gross, right, and How- ard A. Ray as they appeared with winter field equipment at the time of the 1906-1909 bird censuses in Illinois. Usually, censusing was started shortly after daybreak and continued, with inter- ruptions, until late afternoon. No censuses were made during periods of inclement weather, that is, when there was pre- cipitation or very strong wind. The dis- tance traveled in each habitat was paced, tallied with a hand counter, and recorded. Other pertinent information was re- corded: the date, time of day, locality, cloud condition, temperature, and num- ber of each species of bird in each habitat. Examples of the type of field notes taken were published by Forbes & Gross (1923 :448-9). In censusing, Gross and Ray chose the general routes (Forbes & Gross 1921, frontispiece) that they would travel, that is, between certain cities or other land- marks, but the censusing was random in the sense that the habitats were not chosen arbitrarily but were censused as they were encountered along the straight-line routes. I~ttiNnots NAtURAL History SURVEY BULLETIN Vol. 28, Art. 3 Some of the areas censused by Gross and Ray are pictured as frontispieces and others as figs. 16, 20, 21, 29, and 30. Gross and Ray in winter field clothes and Gross on summer field trips are shown in figs. 1.2 and” 3. In 1956-1958, we censused in most of the counties that Gross and Ray had cen- sused, fig. +, although we did not dupli- cate their routes exactly. After driving into a county, we deliberately chose a starting point in an area that seemed to represent the region. From the starting point, we walked a census strip along the perimeter of a square 1.5 to 2 miles on each side and returned ultimately to the starting point. Our rate of coverage, +5— 50 minutes per mile, was comparable to that of Gross and Ray. Though we de- liberately chose each census area, we did Fig. 2.—Alfred O. Gross'on rocks along the Ohio River near. Elizabethtown, Illinois, June 30, 1907. October, 1963 Graper & GRABER: not arbitrarily select habitats, but censused all habitats as we encountered them along our straight-line routes. Thus, the habitat coverage in all our regular censusing was random. In the summer of 1958, we did supple- mentary censusing in addition to our reg- ular censusing; we deliberately chose and Birp PopuLATIONS IN ILLINOIS w oo sr nois at all seasons of the year, but be- cause of the especially variable nature of bird populations in the migration seasons we decided to limit our censuses to the winter and summer seasons. In Illinois, spring migration of birds begins in Febru- ary and extends at least through the first week in June. For some species, fall mi- Fig. 3.—Alfred. O. Gross, left, May, 1908. Gross and fellow ‘students were studying distribution of various species of animals in I]linois. censused additional acreage of certain habitats of limited area, such as marsh and orchard. We did this because we had encountered only a small acreage of these habitats along our regular census routes. Data from the supplementary censusing are included in tables with data from the regular censusing. In northern Illinois, we made censuses in the two northernmost tiers of counties except Cook County. In central Illinois, we conducted censuses through Vermilion, Champaign, Ford, Piatt, De Witt, Ma- con, Logan, Mason, Fulton, McDonough, and Hancock counties. In southern IIli- nois, we censused through Wabash, Ed- wards, Wayne, White, Gallatin, Hardin, ‘Pope, Massac, Johnson, Pulaski, Alex- ander, Union, Jackson, Randolph, Perry, Jefferson, and Franklin counties. The original studies by Forbes & Gross included data on bird populations in IIli- and helpers on a collecting trip near St. Joseph, Illinois This particular field work was not part of the bird censuses of 1906, 1907, and 1909. gration is under way by mid-July, and the migration lasts until December. Therefore, we conducted most of our summer censuses between early June and mid-July and our winter censuses between early December and March 1. Having access to Dr. Gross’ original field notes, we were able to recalculate the 1906-1909 population densities for precisely the sea- sonal periods used in our censuses, thus insuring that the two sets of data were seasonally comparable. Because of the sea- sonal limitations and our recalculations mentioned above, our data for the Gross and Ray censuses do not correspond with data published by Forbes & Gross. Population data in this paper represent summer and winter censuses of the two surveys. [he summer censuses were made during the following periods: in northern [llinois—June 30, July 1-3, 5-8, 1909; June 25-29, July 1-2, 1957; and June 386 30-July 4, July 10-12, 14-15, 1958; in central Illinois—May 22-23, 27-29, 31, July 9-13, 15, 1907; June 22-26, 28-29, 1909; June 18-19, 21-24, July 8, 10, 12, 1957; and June 15, 17, 23-28, July 10, 1958; in southern Illinois — June +8, 10-14, 17-21, 25-29, July 1, 1907; June VERMILION 2 s EOGAR Bia clay CRAWFORD ee Fig. 4.—Areas (indicated by black squares) in which the strip census method of estimating bird populations was used in 1956, 1957, 1958, and 1959. In most areas, censuses were made in both summer and winter, in a few areas in only one of these seasons. The boundaries be- tween the northern, central, and southern zones discussed in this paper are shown by heavy lines. 8-11, 14-17, July 13-15, 1909; June 11-17, July 8-10, 1957; and June 13-14, 18-21, July 8-9, 1958. ‘The winter censuses were made during the following periods: in northern Illinois —December 3, 6-8, 10, 1906; January 2-5, 8-11, 14-17, 1907; December 4-6, 1956; January 22-23, 1957; February 27, 1958; in central Illinois—December 11, Ittinois NarurAL History SurRVEY BULLETIN Vol. 28, Art. 3 13, 17-18, 1906; January 21-25, 27, 29-30, February 1, 1907; December 14, 17, 1956; February +8, 1957; February 5-6, 12-14, 24-26, 1958; in southern IlIli- nois — February 6-8, 9, 11-14, 18-21, 1907; December 27-28, 1956; January 8-13, 1957; and February 7-11, 1958. Forbes & Gross (1923:436) stated that the strip census method used in their — studies limited them ‘“‘to birds of more or less open country.’ Although reduced visibility in woodlands and dense shrub habitat undoubtedly affected the accuracy of the method, data for such habitats were gathered both in the earlier field work and in our own. However, in considering the value of the method, we were con- cerned primarily with open-field areas. In defining habitats, we placed primary em- — phasis on the nature of the land cover, not on the land use. Thus, we classified a stand of alfalfa as a kind of hayfield even if it had been grazed. Ideally, all habitats censused should be represented by comparable large-size sam- ples, but in random strip censuses, such as were used in the recent and earlier — studies, the observers covered different — habitats approximately in proportion to the total acreage of each habitat in the areas censused. For certain habitats (such croplands as corn and small grain, for example) areas of several hundred acres were represented, while for some other habitats (for example, vegetable crops) only a few acres were represented. The — data for habitats represented by only a — few acres are probably not very signifi- cant; thus, there is a certain amount of waste in random strip censusing. i In this paper, we have summarized — virtually all the field data that were col- lected in the summer and winter seasons in both the 1906-1909 period and the ~ 1956-1959 period regardless of sample — size, but the question of what constitutes an adequate census area deserves further — consideration in order to help the reader evaluate the data. - The size of an adequate census area — probably varies from habitat to habitat — and season to season. In many habitats, — open-field habitats especially, bird popula- tions are much more variable in winter — than in summer, and winter census areas should presumably be larger than summer October, 1963 Graper & GRABER: areas. Lo obtain information on the re- lationship between the size of the census area in open fields and the measures of the bird population in such fields, we ex- amined data on open-field bird popula- tions from +27 summer strip counts in SUMMER _ MAXIMUM GOUNTS OF 40r BS _- BIRDS PER. ACRE AVERAGE COUNTS 20 25 30 35 40 45 50 55 60 65 7. SIZE OF SAMPLE IN ACRES Sao wes ry ° 80 WINTER 13.0 MAXIMUM COUNTS OF BIRDS PER PER CENT OF SAMPLES WITHOUT BIRDS on 6 (oh Fo) AND Bolas ~—___ MAXIMUM COUNTS OF sa BIRDS PER ACRE ms ° AVERAGE nm ° x 5 0 [5s 2025) SOpnso= 40) 4515/50" 55) sO" 65 rion SIZE OF SAMPLE IN ACRES Fig. 5.—Bird population data for census areas (samples) of different sizes: (1) the per cent of the areas (samples) on which no birds were found, (2) the average numbers (average counts) of birds per acre, and (3) the maxi- mum numbers (maximum counts) of birds per acre. areas ranging in size from 0.3 acre to 80 acres and from 203 winter strip counts In areas ranging in size from ().2 acre to 7+ acres. Three measures of bird popula- tions in these sample areas are presented in fig. 5. The three measures were (1) the per cent of areas of different sizes void of birds, (2) the maximum counts of birds per acre in areas of different sizes, and (3) the average count of birds per acre for sample areas in each size class. In all strip census areas of 5 acres or less, about +9 per cent were void of birds in summer and 72 per cent in winter, fig. 5. For areas of 6-10 acres, the percentages were 19 in summer and 49 in winter, and, for areas of 11—20 acres, 7 in summer and 23 in winter. In summer, all census sam- ples of 19 acres or more contained at least 1 bird. In winter, 17 per cent of the areas of 21—30 acres had no birds, but all Birp PoPpuULATIONS IN ILLINOIS 387 areas of 28 acres or more contained at least 1 bird. The curves representing the maximum counts of birds per acre in areas of differ- ent sizes, fig. 5, showed greater extremes of bird populations in winter than in summer and consequently indicated the requirement of larger sample areas in winter. Maximum counts in plots of 5 acres or less were about 12 birds per acre in summer and 22 per acre in winter. As the size of the census plot was increased, the curve of maximum counts fell steeply (more steeply in summer than in winter), tended to level out, and attained a nearly constant level at about 25 acres in sum- mer and 50 acres in winter. The average counts of birds per acre in areas of different sizes showed the sig- nificance of the size of the census area. In summer samples, the mean number of birds per acre fluctuated noticeably in sam- ples under 30 acres but was relatively constant in larger areas. In winter sam- ples, the mean fluctuated greatly in sam- ples under 50 acres but tended to level out for samples of larger size. These data suggest that, when the strip census method is used, the minimum size of census areas of open-field habitat should be not less than 30 acres in sum- mer and not less than 50 acres in winter. In discussing results of strip censuses, Forbes (1907:308—-9, 1913:374-5) used the terms most important, most abundant, and more abundant to designate those spe- cies of birds that together made up 85 per cent of a censused bird population, as, for example, the birds of a given habitat in summer. This percentage was selected ar- bitrarily. Because 85 per cent provides a good sample of the avifauna, we used this figure throughout the study in determin- ing the species designated as common in the various habitats discussed. (In deter- mining the common birds in the statewide population, we used 70 per cent, table 56; the number of species that together made up 85 per cent of the state population was too great to be included conveniently in a table.) Our data on Illinois acreages of the various habitats, fig. 6, have been derived from one or more of four principal sources: (1) published records of the U.S. Bureau of the Census (1913, 1961), (2) 388 published records of the Illinois Coopera- tive Crop Reporting Service (Ewing 1959), (3) ene published wetlands survey of the U. Fish and Wildlife Service (Shaw & hot 1956), and (4) pub- lished records of the University of Illinois Agricultural Experiment Station (King & Winters 1952). These sources were supplemented by unpublished records of the 1906-1909 and the 1956-1958 bird censuses. In discussing estimates of Illinois bird populations, we have referred to northern, central, and southern zones of the state, fig. +. For convenience, we based these zones on agricultural districts defined by the Illinois Cooperative Crop Reporting Service (Ewing 1959, map). 1960 1950 Yyy y 1900-5 Ittinors NATURAL History SuRVEY BULLETIN \\SB SH SSP SA yt Vol. 28, Art. 3 In this study, the treatment of two such similar species as the eastern and the — western meadowlarks, as well as the black- _ capped and the Carolina chickadees, offers — a problem. Because in most instances we — could not make specific determinations in these groups, we have usually lumped the data for the two species under one head- — ing, for example, meadowlark (species?) — or chickadee (species ?). The basic quantitative data for this study are presented in two types of tables, the first with emphasis on statistics (ex- ample: table 4), intended only to give — the reader some impression of the inherent variability in the population data _pre- sented, and the second with emphasis on — avifauna (example: table 5), intended to Kd | eA ITER RAAT SOY BEANS { 4 n A og ry 5 H cneiee ‘ : 1850 t : y ‘ : Oct eae 5 WHEAT ORGHARD ! (tt — et —4 Millions of Acres igo0 RESIDENTIAL 1960 1950 OO te2 1900 1850 tL iY ween se weeede Doe SW Fig. 6.—Acreage of various bird habitats in Illinois from about 1800 through the years — of the bird surveys reported here. Acreage data are principally from four sources: published records of the United States Bureau of the Census, published records of the Illinois Cooperative — Crop Reporting Service (Ewing 1959), published wetlands survey of the U. S. Fish and Wild- life Service (Shaw & Fredine 1956), and published records of the University of Illinois Agri- cultural Experiment Station (King & Winters 1952). GRABER & GRABER: October, 1963 provide data on the species of birds found in each habitat. Each table of the second type is arranged with the most numerous or the most frequently encountered species at the head of the list. Species of equal fre- quency are listed in phylogenetic sequence according to the American Ornithologists’ Union (1957). Unidentified birds and birds identified only to genus, except those in Sturnella and Parus, are listed at the end of each of these tables. A few of these tables include species that appear to be out of habitat (for example, the Canada goose listed in table 54, the table for winter forests). The census method required that birds should be counted if they were in or over the census strips in front of the observers. In the example mentioned, a small flock of Canada geese crossed the census strip above some woodlands we were censusing. Thus, the ecological pic- ture presented in this and a few other tables is somewhat distorted. In the summer avifaunal tables for cer- tain habitats, we have designated some species of birds as being breeding species in those habitats. This designation means that the species were found nesting in the habitats either during the 1907-1909 or the 1957-1958 surveys. In this publication, we have adopted the common names of birds as presented by the American Ornithologists’ Union (1957). A list of common and scientific names of all species encountered in the censuses ap- pears in table 55. Evaluation of Strip Census The strip census estimate of a_ bird population presumably has some relation- ship to the true population. A relatively constant relationship is all that we require of a census technique that we use to make comparisons between populations in dif- ferent habitats (or different time periods). The question remains as to how closely the strip census estimate approximates the true population of birds in a given habitat. Cooke (1915:2) felt that the strip census as reported by Forbes (1908) was so radi- cally different from the breeding-bird cen- sus that figures from the two censuses were not comparable. In order to determine how closely the strip census method reflected the true bird population, we ran both strip censuses and Birp POPULATIONS IN ILLINOIS 389 breeding-bird censuses on special study areas and compared the results. “The breeding-bird census technique (Stone 1950:185-6) has been widely accepted as a reasonably accurate estimate of the true bird, population of an area. Our comparison of the two types of census was conducted in June, 1959, on two study plots, each a 40-acre hayfield, located 1.5 miles apart near Sibley, Ili- nois. One field belonged to John Ames, the other to Herbert Brucker. The study plots were measured and staked off into squares of 1.6 acres each. In these areas, we made counts of singing males in the early morning (0600 to 0800 Central Standard Time) and located as many nests as possible. During the month, we determined as closely as possible the num- ber of birds breeding on each of the 40- acre tracts. We conducted breeding-bird counts usually every other day and on alternate days ran strip censuses across the study areas. In making the strip censuses in these fields, we followed the procedure used in censusing hayfields on our regular censuses. We chose hayfields for study because they support a fairly high bird population and a varied nesting fauna, and we were interested in qualitative as well as quan- titative comparison of data collected by the two methods. The two 40-acre fields differed in avi- faunal characteristics and other aspects. The Ames field was rolling and contained a higher percentage in sweet clover, while the Brucker field was flat and contained a higher percentage in red clover. The two fields harbored the same principal species of birds, though in different proportions, fig. 7. Our breeding-bird censuses indi- cated that the populations of birds in the Ames (area A) and the Brucker (area B) fields consisted of bobolinks, 28 and 24 per cent, respectively, of the total breeding- bird population; dickcissels, 25 and 40 per cent; redwinged blackbirds, 21 and 10 per cent; grasshopper sparrows, 16 and 18 per cent; meadowlarks (Sturnella spp.), 8 per cent in each area; and Henslow’s sparrows, 2 and 0 per cent. Our strip censuses showed that the populations of the two areas, A and B, consisted of bobo- links, 39 and 15 per cent, respectively ; dickcissels, 17 and 45 per cent; redwinged 390 blackbirds, 16 and 10 per cent; grass- hopper sparrows, 16 and 22 per cent; meadowlarks, 11 and 7 per cent; and Henslow’s sparrows, 2 and 0 per cent. ‘Though the strip censuses did not show the population characteristics precisely, they clearly reflected the differences between the two fields and provided a_reason- ably accurate qualitative picture of the populations. Quantitatively, populations of the two fields differed markedly, as shown by both the breeding-bird and the strip censuses. AREA A MEADOWLARK DICKCISSEL IGRASSHOPPER SPARROW REDWINGED BLACKBIRD IN HABITAT PER CENT OF BIRDS REDWINGED BLACKBIRD GRASSHOPPER SPARROW MEADOWLARK I_tinois NarurAL History SURVEY BULLETIN HENSLOW'S SPARROW STRIP “CENSUS Vol. 28, Art. 3 The population density of passerine birds, as indicated by the breeding-bird censuses, was 4.6 nesting birds per acre for area A and 2.6 for area B. The density, as indi- cated by the strip censuses, was 4.5 nest- ing birds per acre for area A and 2.9 for area B. The closeness of the two sets of figures is surprising because of the difference in potential between a breeding-bird census and a strip census. In a breeding-bird cen- sus, in which a high percentage of the nests in an area are located, the researcher ARE Be COMO Oe BOBOLINK SOOO i: GRASSHOPPER SPARROW REDWINGED BLACKBIRD 5S D< % » D ¥ AREA B GRASSHOPPER SPARROW MEADOWLARK HENSLOW'S SPARROW REDWINGED BLACKBIRD BREEDING-BIRD CENSUS Fig. 7.—Species composition of the nesting avifauna (excluding game birds) of two 40-acre hayfields (areas A and B) as determined by two types of census, the breeding bird census and the strip census. The histograms show the per cent each species comprised of all birds counted in each habitat. 5 ne ree October, 1963 GRABER & GRABER: obtains a close approximation of the true population density, including both males and females of each species. In the strip BIRDS PER ACRE | 2. 3 4 5 6 u 8 Shs 12+ SAMPLE SIZE IN ACRES il on + 12+ BIRDS PER ACRE Fig. 8.—Populations of nongame birds in census areas of different sizes. The populations were estimated by strip censusing in two hayfields, areas A and B. Strip census areas (samples) were categorized by size (4 acres or less, 5 acres to 9 acres inclusive, 12 acres or more); each sample area represented 14 censuses conducted between June 4 and 21, 1959 (0600-1200 CST). The horizontal line through each open box represents the range of variation in the measure of the bird popula- tion; the vertical line represents the mean pop- ulation based on 14 censuses. Each open box represents one standard deviation each side of the mean, and each shaded box represents one standard error each side of the mean. census, on the other hand, some females (especially incubating females) are prob- ably overlooked, and, consequently, we might suppose the density indicated by a strip census to be less than the density in- dicated by a breeding-bird census. The fig- ures on density presented above do not bear out this supposition. To some extent the similarity in density figures is brought Birp PorpuLATIONS IN ILLINOIS 391 about by the behavior of the breeding males. There is a tendency for males of many species to approach the census strip and enter or cross it. This behavior may represent curiosity or aggressiveness to- ward an intruder; it has the effect of ex- aggerating the count of males per unit of area. By chance, this mechanism appears to compensate for the low count of fe- males during the incubation season. Variations in the strip census estimates of bird populations on the two special study areas are shown in fig. 8. The range of density values tended to decrease in strip census data as the size of the area censused increased, fig. 8. When the area censused was 4+ acres or less, density values for the Ames area ranged from 2.9 to 7.1 birds per acre on different census trips, while the values for areas of 12 acres or more ranged from 3.3 to 5.3. For the Brucker area, comparable values were 1.3 to +.4 birds per acre (4 acres or less) and 2.1 to 3.7 birds per acre (12 acres or more). The data for population densities pre- sented above apply to nesting passerine birds only. Besides these passerines, there was a high population of pheasants in the Sibley area in which the Ames and Brucker fields were located. Ronald F. Labisky of the Illinois Natural History Survey, who has made intensive studies of the pheasant population in the Sibley area, reported that during the 1959 breed- ing season about 1.3 pheasant nests were established per acre of hayfield. Neither the breeding-bird census nor the strip cen- sus indicated a density of this magnitude for pheasants. The breeding-bird census indicated a pheasant population of 0.07 nest per acre on area A and ().12 per acre on area B. The strip census indicated a population of 0.05 pheasant per acre on area A and ().02 per acre on area B. Obviously, the strip census method is much less reliable for estimating pheasant populations than for estimating popula- tions of the more conspicuous passerines. Cooke (1915:2) pointed out that the number of birds per square mile in south- ern Illinois in June, 1907, as reported by Forbes (1908), was less than half the average for the national (breeding-bird ) census; Forbes based his figures on strip censuses. The population data in our paper 392 are of value primarily for comparisons within this study, and the reader should recognize the specialized nature of the data. The greater variation of bird popula- tions in winter than in summer has al- ready been mentioned. It is difficult to de- termine to what degree the strip census estimates reflect the true winter popula- tion. In winter, birds are not so evenly distributed as in summer and they are - less restricted to definite territories. “hese conditions decrease the accuracy of cen- susing, regardless of the method used. The great variation in population data from Table 1.—Bird populations of a central Illinois cornfield in the winter of 1958—59 as de- termined by 40-acre strip censuses on four dates. Intinors NarurAL History SURVEY BULLETIN Vol. 28, Art. 3) four strip censuses in each of two areas in winter is shown in tables 1 and 2. Total. population densities as indicated by the strip censuses varied from 10 to 107 birds per 100 acres in the cornfield and from 35 to 215 birds per 100 acres in the woodland. . Only 1 of the 5 species recorded in the cornfield habitat was found on all four census trips, and only 2 species were found on at least three census trips. In the wood- land habitat, only 2 of 16 species of birds were found on all four census trips, only + species on at least three censuses, and 12 species on at least two censuses. Ad- Birps Per 100 Acres | SPECIES | ‘December 18 | December 19 | December 30| January 13 Laplandslongspur2. 22) ee 5 89 5 12 Moummin pido esse ee ee 18 3 71 Hogtied Varker Se Se ey 12 Ring-necked pheasant 5 as sliree sparro yy =o n 5 ee eA a as 3 2a Lotal birds-per 100: acres A ee 10 107 11 95 Number: ofspectes <2 3 ose ek Z 2 3 3 Table 2.—Bird populations of a central Illinois woodland in the winter of 1958-59 as de- termined by 20-acre strip censuses on four dates. Birps Per 100 AcRrEs SPECIES . December 5 |December 19| December 29| January 13 Downy woodpecker] ea ee ee 30 5 15 zis Red-bellied woodpecker 15 15 5 5 futted titmouse 220s Ol eee ae 37 10 ae ba Commonicrow ses oes ees ee dey fs 30 5 Chickadee: (species?) 2 es an 30 5 oe BLOWNNCLEC Pel so: ik tee Ea eee ees Bz, 5 5 Yellow-shafted flicker__...-_-__________ 22 5 ae Slate-colored junco. ee 22 ai ix 5 Benya ype ts ee ee ee 5 20 es Hairy woodpecker) 2s ee re ee oe =< 2 15 10 Cardinia] iy ee EL Oe es, 7 5 5 5 astern bluebird: 2s ae eo eS 15 ee aoe ae White-breasted nuthatch 5 5 Golden-crowned kinglet 10 aoe cee (Sp arte we eee wee 10 Fs Garoling wren... ee a ee Bas 5 Dendrocopos (species?) —...-_-_------------------- ae 10 Winidentifiedsbird 22 =m ter 6 oe Se alee 15 ee 5 Ze Rotal birds per 100 acres 215 65 130 35 mnmberror specicn. nos 28 ta ee ad 9 9 10 5 October, 1963 Graper & GRABER: mittedly, the sample census areas, +0 acres for open field and 20 acres for woods, were small for winter censusing. The high variability shown in our win- ter census data appeared to be more a characteristic of winter bird populations than a defect of the census method. Re- gardless of its source, high variability makes interpretation of winter data more dificult and probably less reliable than interpretation of summer data. That bird populations of an area may fluctuate greatly from year to year is well recognized. Data presented by Kendeigh (1944:93-4) showed that the number of breeding birds in a 55-acre forest in east central Illinois fluctuated (increased or decreased) from one year to the next an average of 23 per cent (average of differ- ences between consecutive spring popula- tions) in 11 years. The minimum differ- ence (increase or decrease) between popu- lations in consecutive years was 5 per cent and the maximum 44 per cent. Fluctua- tions for particular species were even greater; the red-eyed vireo population changed from 0 in 1940 to 13 pairs in 1941, and the number of house wrens increased from 10 pairs in 1940 to 20 pairs in 1941. Year-to-year fluctuations in winter populations were even greater than in spring populations, averaging +6 per cent (average of differences between con- secutive winter populations) for 14 years. The minimum difference (increase or de- crease) between consecutive winter popu- lations was + per cent and the maximum 133 per cent. Bird populations in open-field habitats are probably as variable as in forests. Data presented by Mrs. H. A. Baker (1955-— 1961) indicated that the number of breed- ing birds on 16 acres of hayfield and pas- tureland in central Indiana fluctuated from year to year, over a 7-year period, by 23 per cent (average of percentage differences between consecutive summer populations). This is the year-to-year fluc- tuation percentage shown in Kendeigh’s summer forest populations. Year-to-year fluctuations greatly com- plicate interpretation of our census data, representing as they do only 4 years in 50. Our conclusions on the subject of popula- tion changes rely to some extent on other ources of history ; they must be considered Birp POPULATIONS IN ILLINOIS 393 tentative and always open to reinterpreta- tion. WEATHER PATTERNS OF CENSUS YEARS The weather conditions that preceded and accompanied the two census periods are worthy of consideration, even though the effect of weather on bird populations is dificult to evaluate. Most of the birds that breed in Illinois spend a large part of the year well to the south of this state, and most of the species that remain through the year are adapted to survive the rigors of Illinois winters. Available data indicate that adult pas- serine birds have a strong tendency to home to the same nesting area year after year. This behavior probably helps to re- duce population fluctuations in a given geographic area. Population stability de- pends, of course, partly on survival of adult birds. Some species, such as the eastern bluebird, are known to suffer large population losses during severe winters. In trying to evaluate the possible effect of weather on the bird populations of Illi- nois, we should consider both the general weather patterns and the extreme condi- tions that may have affected bird survival. No prolonged period of adverse weather (excessive precipitation or extremes of temperature) occurred between 1899 and January, 1904. But unusually low tem- peratures in January, February, and April, 1904, may have had an adverse effect on bird populations, particularly of early- nesting species. Record-breaking cold oc- curred in February, 1905, but it did not endure for long and probably had little effect on bird populations. Precipitation was not unusual in any of these years. It seems doubtful if weather factors (even the cool spring of 1904) in the years lead- ing up to the 1906-1909 surveys had any widespread effect on the bird populations censused in these surveys. —emperature and precipitation patterns in the survey years themselves, figs. 9 and 10, were probably more important. The winter of 1906-07 was compara- tively warm and moderately rainy, but the following spring and summer months were extremely cold, the coldest at least since 1878, and the cold, especially that in April and May, could have had a notable effect 394 on the state bird population. The census data indicate that the 1907 breeding popu- lation of birds in Illinois was conspic- uously lower than the population of 1909, a normal year in terms of weather. The fact that many species had low populations Ituinors NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 in 1907 will be mentioned repeatedly in the following text, and the reader should bear in mind that the adverse spring weather of 1907 may have played a role in this depression. The winter of 1908-09 was mild, the following spring and sum- — 8 Ww 7 © ie x. PRECIPITATION ar P¢ 2 aH LONG Ee + TERM wi -I AVERAGE -2 iS S -4 o -5 J -649 Ww ee 7 pass) 6 5 = 4 PRECIPITATION ° 3 a 2 ao 1 LONG + TERM na ! AVERAGE Oo ' bing a S10 oe, SI 1 faa} 1 a 8 \ ' ": at 6 i wn i | Ww 5 1a TEMPERATURE Sah iv PRECIPITATION 2 3 H Fen 1 | 1 ' LONG ore ¢ TERM t AVERAGE iH uj -4 a "5 w -6 O57 Fig. 9.—Temperature and precipitation deviations from the long-term averages in the northern, central, and southern zones of Illinois during and immediately preceding the years of the bird surveys of 1906-1909. SE) survey but it second bird ——||'958——— the Weather in the years from 1952 to the of (1956) was marked by drought, usually quick to recover from a depression. Ke) Sy% Birp PopULATIONS IN ILLINOIS beginning Bird populations are 1956 GRABER & GRABER: level. lation of birds in Illinois was well above 1907 mer were near normal in terms of weather, and the 1909 level of the breeding popu- October, 1963 the os wW tl os w os uw ra (ae (ho) [as roa jog (eo) 2zao oud =) ow at oOowW aed ak iF Ee Si a yl (ve WwW > > e v a af v 2 v = "i oc a , SAV & = ‘ony TAP E so LW Ns. ane NAP i -<-o-™ fe ~ ‘Nar AVW a AVW ‘UdvV a toe ‘dV “UV a ina ee ‘MW ga4 = ey Se erse= cea NUE ‘ > OS St copes f NUE ‘930 mies O «2° ‘930 AON+ 2 -- E ‘AON 190 fe) eS =) ‘L90 MSS oa a = das 9nv re S es ‘onv ALAM a Od ar C = a a nar ore oO = ‘NA AVW = Ww AVW YdV4 fs iss ‘Yd “UV a ‘UV ‘a3a4 AS ene ‘@34 ‘NUP ‘NVP 93a 5 a ‘930 AON er ‘AON 190 Mees ‘190 das > eo ‘das ‘OnV wa ‘ONY “Ine LW ne NAP < ‘NOP AWW ay AVW ‘UdY Oo ‘ud “YW = YW ‘a34 ‘834 en ‘NV? =|! isile WS) 2) 76 1956 Fig. 10.—Temperature and precipitation deviations from the long-term averages in the northern, central, and southern zones of Illinois during and immediately preceding the years of the bird surveys of 1956-1958. 396 was not unusual otherwise. We do not know what effect low precipitation had on bird populations, but by 1956 the precipi- tation level was coming back to normal, and we judge that the dryness of the earlier years probably had little effect on the bird populations surveyed. The census years of 1956-1958 showed a variable weather picture, fig. 10, with temperature and precipitation fluctuating to about the same degree as in 1906-1909. The winter of 1956—57 in Illinois was relatively warm (except in January) and precipitation was normal; the following spring and summer were about normal in temperature and normal or above normal in precipitation. No known weather con- ditions in this year would have had any special effect on bird populations in the state. The start of the winter of 1957-58 was mild, and precipitation continued to be normal, but February and March were very cold. The cold may have depressed populations of at least a few species of birds. The late part of the following spring was warm, but the summer was cool and wet. The summer conditions may have had an adverse effect on production of young birds, but the adult population, ILtrnors NarurAt History Survey BULLETIN Vol. 28, Art. 3 with which we were primarily concerned, was probably not greatly affected. Our census data show that the state population of nesting birds was about the same in 1958 as in 1957 and tend to support the view that the early spring cold in 1958 had no general depressing effect on the state bird population. The years 1909, 1957, and 1958 in IIli- nois were probably similar to each other in terms of weather and its effect on bird populations. The 1907 bird population was depressed, and weather probably had a bearing on this depression. BIRD POPULATIONS IN SUMMER HABITATS Between the dates of May 22 and July 15, 14,447 acres were covered by strip censuses, 7,662 acres in 1907-1909 and 6,785 in 1957-1958. Acreages of the dif- ferent habitats censused in the two study periods combined ranged from 4,003 acres of corn to 1 acre of sugar cane. Because it is pointless to discuss bird populations in habitats represented by only small acreages, we have disregarded habitats represented by less than 50 acres. In table 3 are listed the summer habitats discussed in Table 3.—Acreages of habitats covered by summer strip censuses in the three zones of Illinois, 1907-1909 and 1957-1958. NorTHERN ZONE| CENTRAL ZONE | SOUTHERN ZONE Type oF HABITAT 1907- | 1957- | 1907- | 1957~ | 1907- | 1957— | 2OTAL 1909 1958 1909 1958 1909 1958 Corn (all ty Pee) 353 616 1,159 629 987 259 4,003 Pasture. e4. 193 279 442 171 882 120 2,087 Sy. Sos a 241 166 596 123 183 10 1,319 Mixed hay (including mowed). 175 212 125 89 534 vir 1,212 Forest (all types) — beeerieee Woe! 2 177 16 214 60 340 809 Soybeans ieee ou: 167 ‘e- 489 ies 121 777 Wheat (including. shocked) ee 6 16 169 63 381 138 773 Fallow fields es Pe nse ea) 24 48 24 37 319 230 682 Red clover... eT ie 2 Nae oS 11 110 46 90 104 85 446 esiential areas 4c. os a! 11 160 8 75 35 98 387 Plowed ground Le See 3 20 11 28 134 139 335 All shrub and hedge. eBay ee Se 4 47 3 70 56 151 331 Ungrazed grass s Wg 15 96 1 49 41 88 290 Alfalfa GPE Maat USS LR Sar) Me SE Ret? 2 138 7 41 tits 49 237 Orchard Re ote eS ae raat 36 6 Uf 45 78 172 Marsh Beg RS wer eh OE he 19 90 3 1 26 16 155 Garden crops es 40 5 20 1 45 ate) 111 Small grain stubble 3 1 13 1 76 94 Srreetu lover: one ee Se Sib os > 26 ‘ 25 1 5 57 PNATIO PANIC, PVE + Mec 27 eat 18 2 14 5 34 Total .. sad ea Te 17. 2,412 2,639 2,215 3,848 2,080 | 14,311 October, 1963 GrapeR & GRABER: this paper and the acreages covered by the strip censuses. Population data in both tables and text refer to supposedly adult birds. Juvenile birds were counted during the censuses, but, in order to eliminate a source of vari- ability, we did not include obviously ju- venile birds in population calculations. Cornfields (Summer) In terms of acreage, corn is the prin- cipal crop of Illinois. The cornfield habitat comprised almost 28 per cent (4,003 acres) of the land censused in the sum- mers of 1907-1909 and 1957-1958, table 3. From the data sources mentioned pre- viously, we calculated that corn acreage declined from about 10,400,000 acres in 1907 to 8,400,000 in 1957. Practices in corn culture have changed, but the char- acteristics of cornfields at the time of year the censuses were made have remained the same, fig. 11. At this season, the young plants in widely spaced rows (about 40 inches apart) usually varied in height from 3 or 4 inches to 2 feet, though some fields with plants over 3 feet in height were censused. The dominating feature of the cornfield habitat in early summer is bare ground. Quantitatively, corn is poor bird habi- tat, figs. 22-24. Mean numbers of birds Birp POPULATIONS IN 397 ILLINOIS per acre in corn for all census years in the three zones of the state in summers varied from 0.3 to 0.9, and the extreme variation for consecutive census years was 0.7 to 0.3 in 1957 and 1958, table 4. Population densities were consistently higher in the northern zone than in other parts of the state. Also, they tended to be higher in the later than in the early census years, but the extreme annual variations preclude any precise conclusion on changes, between 1906 and 1958, in density of bird populations in cornfields of the state. Though there was no conclusive evidence of a general quantitative change in total bird population, the composition of the avifauna had altered. At least 60 species of birds were re- corded in summer cornfields in the two study periods combined; this figure prob- ably reflects the large acreage covered more than it does the quality of the habi- tat. The complete list of species, with pop- ulation figures for each, is presented in table 5. Only 5 of the species (horned lark, grackle, house sparrow, mourning dove, and redwinged blackbird) were re- corded in this habitat in all years and all zones. The number of common species (those comprising 85 per cent of the population) in summer cornfields was higher in 1907 Table 4.—Statistical data on summer bird populations in Illinois cornfields as determined by strip censuses in the three zones. Data are (1) from all cornfields censused and (2) from sample areas (each 10 acres or more) in these fields. ALL CORNFIELDS SAMPLE AREAS CENSUSED ZONE AND Birds Per Acre YEAR Hee Birds Per Acres Acre ee Standard | Standard) Mean + Range Mean Deviation | Error 2S.E Northern SS () 9 eek ee 351 0.6 8 0.3-0.8 0.6 0.2 0.1 0.4-0.8 SYS 97 eee ea aa 317 0.9 iO 0.2-1.5 0.8 0.4 0.1 0.6-1.0 DOS Bee ek 299 0.9 6 0.0—2.4 1.0 Central 1 (7) eae ee eee 668 0.3 11 .1—1.0 0.3 0.2 0.1 0.1-0.5 US) ae eee 488 0.5 7 .2-0.7 0.4 Lt. = iE a Si alae Seo 328 0.7 13 21.5 0.7 0.4 0.1 0.5-0.9 HG Ren eee hee. 290 0.3 5 .0-0.4 0.2 Southern Ly oe ee ee 550 0.4 19 0-0.8 0.4 0.2 0.1 0.2-0.6 (0) eae ee 433 0.7 iba 3-1.5 0.7 0.3 0.1 0.5-0.9 G5 a ena 103 0.5 1 aes 0.3 = we NS 5 Sys a 156 | 0.7 10 0.0—1.7 0.7 0.5 0.2 | 0.3-1.1 398 Ittinois NATURAL History SuRvEY BULLETIN Vol. 28, Art. 3 strip censuses in the three zones. Figures in parentheses indicate number of acres censused; Table 5—Summer avifauna in Illinois cornfields (birds per 100 acres) as determined by + indicates less than 1 bird per 100 acres; * indicates breeding species in this habitat. No2tTHERN ZONE CENTRAL ZONE SOUTHERN ZONE aes | 1909 1957 1958 | 1907 | 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 | (351) | (317) | (299) | (668) | (488) | (328) | (290) | (550) | (433) | (103) | (156) *Horned lark 10 8 Common grackle| 13 8 y) bo Le) me DOW © wWwonni 39 7 5 43 13 5 11 1 4 1 House sparrow___. ; Mourning dove ___. Redwinged black- birds -2 2d 3 9 6 1 2 1 Meadowlark (species?) 1 2 4 *lldeers. 2 2 Brown-headed cowbird _......._.. 1 Starling: <2 ols Barn swallow. 1 Robin Tes 2 Common crow... 2, *Vesper sparrow. 4+ Brown thrasher___ + Yellow-shafted flicker Saree 3 Eastern kingbird__ 2 Field sparrow 1 American gold- finch Ere 2 Dickcissel ero Indigo bunting + + a Mockingbird Red-headed woodpecker __. ok + 1 es 1 2 + 3 7 5 7 4 8 1 6 6 5 ab 7 6 6 1 1 vf “he + + 2 4 lie ees 2 8 we aA _ we mtiyat! + < ai bat iS ts R 1 pak pk} “ARS — _— c tat tt 4 ++. +++ ++. ato. 2 io Upland plover __ Chimney swift ~ Lark sparrow Loggerhead Sires se i 1 Blue jay pa 1 Bobwhite et Eastern bluebird _ Sparrow hawk _ Sarda). 1e ae Catbird | ad Ring-necked a pheasant i = ey. ie arp Rede 2 vig WA Re ae Spotted sandpiper | __ oo Purple martin _ Ue Bobolink a. 1 aie ae Yellowthroat + stl + ae ice Turkey vulture Re Ons ne: zh oe Eastern phoebe _ ee see Chipping sparrow a il F Orchard oriole _ ake at ee + Greater prairie - chickens 2 ==) 1 os we gia oh ote ms bait ae oz a Brewer’s black- | 2a Sete pall atone sor a4 1 ae Traill’s flycatcher | _- Ex 2 + Rufous-sided POWHeE oe a me Bt ok ne ee i +] + Se a ot ee _ + i++ St to ee a ++ we att ae oa ares 4 H + +4) +4 aot i ++. i++ per er ae +++) 41 SEs ed October, 1963 Graper & GRABER: Birp POPULATIONS IN ILLINOIS 399 Table 5.—Continued NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE poles 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 1907 | 1909 | 1957 | 1958 (351) | (317) | (299) | (668) | (488) | (328) | (290) | (550) | (433) | (103) | (156) Song sparrow. = es i ae oe ate a2) ae ae are ati Great blue heron | —~ Res a ss eres ze x aa ae. acs eS. Black-crowned | night heron. AF =o Ss ss uae a a ee — Red-tailed hawk _ igs et ae ia ee a + ie ae Red-shouldered INES eat ee a eee a —_ ee. an a == mal — me Yellow-billed cuckoos =F. =e a =e = Beet sie a Be eee = ae Common night- jalpe iyi) eae en nee Me cet + bet aw oe ive Ns bat Belted kingfisher | _- me es + ae ae “ee aes re a Downy wood- Deckers ss ots ot = ats = = ae Tt bate Tree swallow oral a + es a es ee es ete Bewick’s wren a = pe tie ses am Mi ae -h Carolina wren___| ---- one see = a es ae + oe Baltimore oriole —| __ ees a ass ne ae. Hl eee + Rose-breasted grosbeak ______ -++ ee a8 28 == oe i wie Grasshopper | SpaLrow=.— = = ws =. = —- oe Jue as tae ze =e = Unidentified bird. | 3 1 ede ee 1 2p lite 1 1 1 2 Total birds per | 100 acres... 63 86 58 Bf) 47 73 52 ND 74 47 72 Number of species | 28 24 28 35 25 19 19 37 36 17 19 Fig. 11—Cornfield habitat at the stage of growth encountered at the time of the June censuses. Photograph taken in Champaign County, June, 1958, by Jean W. Graber. 400 ItLinois NaturRAL History SurRVEY BULLETIN and 1909 in all zones censused than in 1957 and 1958, fig. 19. The pattern is one that can be observed over and over for the open-field habitats; that is, in these habitats the earlier avifauna of com- mon species was more varied than the re- cent. Related to this change is the fact that only three species (horned lark, red- winged blackbird, and barn swallow) comprised more of the cornfield popula- tion in 1957-1958 than in 1907-1909, . while at least nine species were less prom- inent in the recent than the earlier corn- field avifauna, fig. 12. 70 60 40 30 Vol. 28, Art. 3 In northern and central Illinois, by 1957 the horned lark had become the pre- dominant cornfield species, a change re- flected in the density figures, table 5. The © change in the southern zone was less — pronounced. i The nesting avifauna for cornfields — probably is composed principally of three — species: the horned lark, vesper sparrow, and killdeer. Because so much of the summer avi- fauna of cornfields does not breed in this — habitat, the list of species in table 5 must _ reflect marginal or edge habitat to some CORNFIELDS NORTHERN ZONE ---- CENTRAL ZONE —— SOUTHERN ZONE ------ a 20 Ww e 2 > o oO 10 o a x oa oO 5 1907 09 5758 0709 5758 0709 5758 0709 5758 0709 5758 0709 £57 58 os HORNED REDWINGED BARN GRACKLE MOURNING CROW is LARK BLACKBIRD SWALLOW DOVE = 10 10) a 0709 5758 O709 5758 0709 5758 0709 5758 0709 5758 O709 5758 FLICKER ROBIN RED-HEADED KINGBIRD MOCKINGBIRD BLUEBIRD WOODPECKER Fig. 12.—Relative abundance of common species of birds censused in cornfields of the northern, central, and southern zones of Illinois in the summers of 1907, 1909, 1957, and 1958. Only those species are included that showed changes in relative abundance (per cent of all birds counted in cornfields) between 1909 and 1957. October, 1963 Graper & GRABER: extent. In all of the census years, regional differences were apparent. The cornfield avifauna of the central zone in summer was poorer both in number of species and in density of population than that of either the northern or the southern zone. Soybean Fields (Summer) Soybean acreage increased in Illinois from a few thousand acres before 1920 to more than 4,000,000 in 1954 (Ross & Case 1956:71); 777 acres of soybean fields were censused in 1957-1958. Soybeans were one of the crops charac- terized by considerable areas of bare ground at the start of the nesting season. In early June, at the start of censusing, the plants were less than 6 inches in height; by the end of the summer census season they reached 12 inches or more. During this period, the areas of bare earth were gradually closed in by the plants, and the habitat probably became less de- sirable for the open-field bird species that predominate in bare-ground habitats. Soybean fields were about the poorest of bird habitats, both in number of species and number of individual birds, figs. 22— 24. The average number of birds per acre of soybeans for the various years and zones in summer ranged from 0.1 to 0.9. Pop- ulations tended to be lowest in the south- ern zone, tables 6 and 7. In central IIli- nois, the zone for which we had the larg- est samples, mean densities were 0.9 bird per acre in 1957 and 0.5 in 1958, table 6. Maximum variation of bird populations in any one zone in consecutive census years was from 0.1 to 0.5 bird per acre, in south- ern Illinois. At least 28 species of birds were iden- tified in soybean fields in the summers of 1957 and 1958, table 7. Though no spe- cies was recorded in this habitat in both years in all regions, the horned lark, grackle, redwinged blackbird, mourning dove, and goldfinch were reported with high frequency. Probably only the horned lark and the vesper sparrow nested regu- larly in this habitat; the horned lark was the predominant species. Plowed Fields (Summer) In early summer, relatively little Illi- nois land can be classed as plowed fields. Birp POPULATIONS IN ILLINOIS 401 Only 335 acres of this habitat were cen- sused in summers of the two study pe- riods. Despite the total lack of cover, plowed fields had avifaunal associations about comparable to those of cornfields and soybean fields. Bird population densities in plowed fields in summer varied from 0.6 to 1.4 birds per acre (57 birds per 100 acres in 1907 to 140 birds per 100 acres in 1957, table 8). In the southern zone, the only one in which large areas of plowed fields were censused, these fields held popula- tions of about 0.6 bird per acre in 1957— 1958, indicating relatively poor habitat. ‘Twenty-nine species of birds were iden- tified in plowed fields in summer, table 8; this fauna was slightly richer in species than that found in urban residential areas. Probably a very low percentage of the species found in plowed fields actually nested in this habitat. Probable nesting species were the horned lark and the kill- deer. Only in the southern zone was the cen- sus area of plowed fields large enough to warrant avifaunal comparisons between the two census periods. In this zone, 10 species of birds comprised the common summer avifauna of plowed fields censused in 1907 and only 7 species in 1958, fig. 19. In plowed fields, as in soybean fields and cornfields, the horned lark was the pre- dominant summer species, figs. 12 and 13 and table 7. Oat Fields (Summer) The acreage of oats in Illinois de- creased from about 4,300,000 acres in 1907 to 2,800,000 acres in 1957. The reduction was accompanied by an increase in soybean production. In all census years, oat production was higher in the northern two-thirds of the state than in the south- ern third. In summers of the two study periods, 1,319 acres of oats fields were censused, table 3, only about 300 acres in 1957- 1958. Only 10 acres were censused in the southern zone in 1957-1958. At the time of the summer censuses, the oat plants had attained nearly full growth (12-18 inches) and were headed out. The fields were green in the early part of the census and ripened before the end of July. Most fields had scattered weeds that produced 402 Intinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 Table 6—Statistical data on summer bird populations in Illinois soybean fields as deter- mined by strip censuses in the three zones. Data are (1) from all soybean fields censused and (2) from sample areas (each 10 acres or more) in these fields. ALL SOYBEAN _ FIELDS CENSUSED SAMPLE AREAS ZONE AND Birds Per Acre YEAR : ees | Acres Birds Number Per Acre R M Standard | Standard} Mean + ange ean | Deviati E eviation rror Northern 1957 24 0.4 oe nae = 1958 143 0.7 6 0.1-2.1 0.8 f Central 1957 250 0.9 9 0.4-1.5 0.9 0.4 0.1 1958 239 0.5 9 0.2—0.9 0.6 0.2 0.1 Southern 1S Lo} rahe sateen MR 46 0.1 3 0.0-0.2 0.1 1958 a 0.5 4 0.2-0.5 0.3 Table 7—Summer avifauna in Illinois soybean fields (birds per 100 acres) as determined — by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused; — + indicates less than 1 bird per 100 acres; * indicates breeding species in this habitat. NORTHERN ZONE CENTRAL ZONE 2 S.E. SOUTHERN ZONE SPECIES 1957 1958 UO 1958 (24) | (143) | (250) | (239) PpELOLDeG sar ke sects he We ee ee AVES. 33 Vi 36 Common’ oraek) ese A eas 21 10 4 1 Rea vwingeediblackbind wea) es ee ee aH AD 5 2, 2 AVEO EET (cl Oye ee ee Sees A el eee A 4 6 2 EAOUSE( SP ANT Oy ee 2c Yn Pe 2 8 3 Meadowlark (species?) 2) Sis 3 3 2 American po) ditin c bie: ak al ae ae a 4 3 1 1 1 CS IC ee Sela EAR Dacha tan eat Pia tes Weg Ne 2 DES Ey ART SVU LO Wye oo rata She a ep ue clea) P 1 + 2 Ring-necked’ pheasant <4 =. aes 4 ey Spotted sand piper ee ee 4 Ste jails jBsVobysZeRoY 60 0°) 0} gad Meet MineDs Res Me! Wein Mewar Sy + + 1) oy) Paes eg Dee AP PENN oe SRI Es BNO ps SIU an 1 a + Vesper SpabiO yy 2 et aoe Fe ed 3 IMI yes thts ce tes ee LBs Sr PR ee Be eet 2 Stas latig: pace et aes sels ee eee pee ee ee 1 ihe 1 Mocking bind 2/25. 60.8 Vee Ssh eee eee + sa Mick cissel vy Fee Sos ee Ae eo EE Be 1 + Rurple martin ec. on oe el ee eae 1 ‘ 503 Savanna hisparr oy ee ee 1 eat MGATECSD ALTO Wisc oer be eae eee oes = 1 Rield:sparko weet Ut eer ee i ee 1 ues z pburkey-vultutetes vs 5 outa ye a ae ae é BOD White ses 8 ee ee Ae UR ne Pin Pale + plana mlewers oe ee ee ean Se =F orserhead: shrikes ew te a es + Bee *Brown-headed cowbird =". eee pot ae Grasshoppersparrow. 8 2 ea Pee ee + Winidentitved! bird sae le eee tip i cee ane ae 1 1 1+ Total birds per 100 acres. 45 al 88 ao IMBErOL speclegus. <2. Seo ce ee ea eee 5 14 17 14 1957 (46) | aX! 1958 October, 1963 Graper & GrRaBeR: Birp PopuLATIONS IN ILLINOIS 403 Table 8.—Summer avifauna in Illinois plowed fields (birds per 100 acres) as determined by strip censuses in two zones. Figures in parentheses indicate numbers of acres censused. | CENTRAL ZONE | SOUTHERN ZONE SPECIES | 1957 | 1907 L909E | SLI 57 1958 (25) | (68) | (66) | (83) | (56) © Doieieyol, eye RI Re 92 6 15 13 14 Parinvncneadedscovw bird eel 8 1 35 4 ) MeO GO Views ee res el Te 12 | 9 21 hae 7 ALN NG ere 22 SU NaS I RES pl cl we 4 om A7erall “LORELS CIDGNETEG) pieces es a ee ee 16 2 a xe Robin cep See SPOS A ae ee eee ee eee Tien | 8 2 Reemiieniveraeile: oe) a iI i 8 2 S) Beeteniecing binds = esse ee 8 4 1 2 Lu BARMISEES PAE OW). 5.20 ee Se 3 9 3 madwyiioed) Dlackbird= 2 1 * 4 7 Eastern meadowlark......_ ee es 1 1 6 3 Bieldesparrow...< 2 ok | IT, Be a ee) ae 8 f Previethica sere 3 ee ee 1 6 sm MTOR DUNT ee d 4 : 1 z PraStennmolmeb ind = = 6 | Reetaticd hayes ee 4 te | | Red-headed pigedpeeker Ue he atiel ae acorn at ESS 4 Ih gees SRCOMORUG HOV yee eee ef Be oat | 2 2 Baenvilieks SavyGl ie ee eee le Houta 4 tical etnies vt wa |e Se i a oe ai A) Eoggerhead shrike___________. ee 1 ASS es 1 3 CC THRUIERURI SE YA cm : 3 = | CUNCE) RCTS NG Pa Ta is | 1 2 Mellow-shafted flicker... a 2 fed-shouldered hawk... | Ia 1 Bobwhite. re 5 ae LA NS aa gegen 1 “Ul ypollezurnyal yo) aia ea eS Se oe a a | | tie] falack-billedvcuckoo..= 22. 1 Mowmny woodpecker 2 | ote i a en aps Watal birds per 100 acres... 140 27 eel a 62 56 Number of species 6 | 19 15 13 11 30 ’ mA PLOWED FIELDS 20 , SOUTHERN ZONE PER CENT OF BIRDS COUNTED IDO7O95 57/58 0709 57 58 0709 5758 HORNED REDWINGED EASTERN LARK BLACKBIRD MEADOWLARK 07 09 57 58 MOURNING DOVE 0709 5758 ROBIN Fig. 13.—Relative abundance of common species of birds censused in plowed fields of the southern zone of Illinois in the summers of 1907, 1909, 1957, and 1958. s are included that showed changes in relative abundance (per cent of all birds counted in plowed fields) between 1909 and 1957. Only those species Ittinoris NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 404 an aspect more like that of hayfields than For all census years and zones, mean — other grain crops, and the avifauna showed _ densities of summer bird populations in — some resemblance to the nesting avifauna oats varied from 0.5 to 2.7 birds per acre; — in hayfields. the greatest variation in consecutive years — Table 9.—Statistical data on summer bird populations in Illinois oat fields as determined ; by strip censuses in the three zones. Data are (1) from all oat fields censused and (2) from sample areas (each 10 acres or more) in these fields. The data from sample areas are for — breeding species only. ALL OAT FIELDS CENSUSED SAMPLE AREAS | i | | | | | ZONE Birds Per Acre Birds Per Acre (Breeding Species) — AND —— | —__— E ee YEAR | Acres | es Number All Ing Observed Mean Species Species Range . P Only g Northern 1 Ut) | Ut TA ale a te ty 241 0.5 0.1 ii 0.0-—0.3 0.1 tL feel ia le eS 95 Ary 2.0 5 0.9-3.8 2.0 TA Ly fata eae A ey 71 1.3 1.2 3 0.2-1.8 re Central j A 1 fata, eke lee CAS ak 408 0.6 0.2 10 0.0—0.8 0.2 GO Die haat Ft 188 0.6 0.3 6 0.1-0.4 0.3 | I. fy pe Reb Sat Whe Se 67 Ld 0.7 4 0.1-0.4 4 LOSS see 56 1.0 0.3 2 0.2-0.6 g Southern iN) 07 facta es Cee age SETS 145 0.5 0.2 8 0.0—0.7 0.2 SST) Eee ace Sean EE 38 1.0 0.6 2 Bs £m 70 ’ I 60 iH ig a40 | WW r F I Zz | 2 I ° | © 30 I ra | A a ! fin o ! ‘ike . 1 / OAT FIELDS o 20 | ; \ NORTHERN ZONE ---- 5 : \ CENTRAL ZONE —— a I f I oc WwW 10 a ie} 190709 5758 0709 57 58 0709 5758 0709 5758 0709 5758 REDWINGED BOBOLINK GRACKLE MOURNING COWBIRD BLACKBIRD DOVE 4 Fig. 14.—Relative abundance of common species of birds censused in oat fields of the northern and central zones of Illinois in the summers of 1907, 1909, 1957, and 1958. Only those species are included that showed changes in relative abundance (per cent of all birds counted in oat fields) between 1909 and 1957. October, 1963 Graper & GRABER: was from 2.7 birds per acre in 1957 to 1.3 in 1958, in the northern zone, table 9. Densities were higher in the northern than in other zones and in the later than in the early series of censuses. In 1907-1909, Birp PoPpULATIONS IN ILLINOIS 405 the density of bird populations in oat fields ranged from 0.5 to 1.0 bird per acre and averaged 0.7, about comparable to density of the populations in cornfields. In 1957 and 1958, the population in oat Table 10—Summer avifauna in Illinois oat fields (birds per 100 acres) as determined by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused; indicates breeding species in this habitat. + indicates less than 1 bird per 100 acres; * SPECIES NORTHERN ZONE CENTRAL ZONE | SOUTHERN ZONE 1909 (241) 1957 (95) 1958 (71) 1907 (408) 1909 (188) | 1957 | (67) | 1907 (145) | 1909 (38) *Redwinged blackbird = HOUSE Sparrow... BPeRes apy iyi se oe *Meadowlark (species?) Common grackle—.- ER GISSG let se se boro a Rilounmime dove LVDL DT TLE Sa a ee American goldfinch.____--_ Barn swallow. Bastern kingbird mrows thrasher ee int Se ee = *Brown-headed cowbird ielideer. si *Grasshopper sparrow mipland’ plover 20 Bellowthroat.. 0 Sparrow hawk... Pirie martin. et iudico bunting: = Bpeidesparrow== 2 be Sark sparrow... -) Dill DATE ea a aS Red-headed woodpecker Momperhead shrike— __—- See Teatiny cl leer see we a *Vesper sparrow_...___.__= BOMSUSPArlLOW 2. lrit swallow. 28.2 Shin ee Bastern bluebird... Savannah sparrow. Bachman’s sparrow. Black-crowned night heron _ astern phoebe. Baltimore oriole... Total birds per 100 acres _ Number of species mies Oe Ae fw! 55 22 107 23 78 iif 10 268 18 87 3 20 3 — Re OD WW 134 11 Coun >_ ee Posiecte, torte ++} 4) o 1 | 61 27 Wh eens Wes S cet oO 0 | Etre | | +4 Ee Ww 2 9 13 6 6 5 25 21 1 1 111 100 nee eS So} NNR | 43 | 20 103 11 406 ILLinois NATURAL History SurRvVEY BULLETIN Vol. 28, Art. 3 fields ranged from 1.0 to 2.7 birds per Population densities of breeding species acre and averaged 1.5, a density well showed minimum and maximum figures above that for cornfields. for 1907-1909 of 0.1 bird per acre (in the Table 11.—Statistical data on summer bird populations in Illinois wheat fields as determined by strip censuses in two zones. Data are (1) from all wheat fields censused and (2) from sample areas (each 10 acres or more) in these fields. The data from sample areas are for breeding species only. ALL WHEAT FIELDS CENSUSED SAMPLE AREAS Gants Birds Per Acre Birds Per Acre (Breeding Species) AND ; YEAR Acres All Breeding Number Obese Species Species Range Mean | P Only g ; Central 1 62) Ut eee So eS 141 0.8 0.2 4 0.0—0.4 0.2 Southern Os eee ee eee 227 0.8 0.2 10 0.0—0.5 0.3 1909. yee 75 0.6 0.1 3 0.1-0.2 0.2 GY; edits rw OS ea 97 0.6 0.3 + 0.0-1.4 0.4 70 WHEAT FIELDS eo CENTRAL ZONE —— SOUTHERN ZONE —----- PER CENT OF BIRDS COUNTED 5758 0709 5758 REDWINGED DiCKCISSEL INDIGO GRACKLE HOUSE MOURNING BLACKBIRD BUNTING SPARROW DOVE Fig. 15.—Relative abundance of common species of birds censused in wheat fields of the central and southern zones of Illinois in the summers of 1907, 1909, 1957, and 1958. Onl those species are included that showed changes in relative abundance (per cent of all birds counted in wheat fields) between 1909 and 1957. & October, 1963 Graper & GRABER: northern zone) and 0.6 per acre (in the southern zone) ; for 1957-1958, these fig- ures were ().3 bird per acre (in the central zone) and 2.0 birds per acre (in the north- ern zone), table 9. Because census samples were small for the later years, we must be cautious in drawing conclusions, but the data indi- cate that summer bird population densi- ties increased in oat fields between 1909 and 1957. The change in population den- sities of birds in this habitat can probably be attributed to population changes in a few species, particularly the redwinged blackbird and the bobolink, fig. 14. Birp PopuLaTIONsS IN ILLINOIS 407 At least 44 species of birds were re- corded in oat fields in summers of the two census periods combined, table 10, but only 2, the house sparrow and the east- ern meadowlark, were found in all zones and in all years. The number of species recorded was considerably greater in 1907-1909 than in 1957-1958, probably because of the greater acreage covered in the early census period. Wheat Fields (Summer) The acreage of Illinois land planted to wheat has varied greatly since 1909. From about 2,000,000 acres in the period 1890-— Table 12—Summer avifauna in Illinois wheat fields (birds per 100 acres) as determined by strip censuses in two zones. Figures in parentheses indicate numbers of acres censused; + indicates less than 1 bird per 100 acres; * indicates breeding species in this habitat. CENTRAL ZONE SOUTHERN ZONE eeacies 1907 | 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (28) | (141) | (32) | (31) | (227) | (75) | (97) | (41) = | louse Sparrow. ==) Pete 257 14 ee 3 25 7 oN 7 *Redwinged blackbird + 11 ae bs 5 2 20 113 RI CKGISSGlmeeeene ea eee te BS 7 if 19 26 8 a iio al Nrounminpidovers 222 18 3 wee nas 18 5 Goa pt2 Wommon grackles = 7 11 wus = 3 2 3 29 oducobunting 2) eo ee sae 9 3 9 3 22 *Meadowlark (species?) oct 11 3 6 12 2 5 5 Field sparrow____-_---.--._.- a ti sae Ba One ae 6 Z 9 4 2 exch yyy te see sa see ee 5 4 2 9 Lon 5 Barmeswiallov, 22 et iB 3 6 aoe a 1 10 Horned lark. — aie Cee 5 ee 16 ms bas oe is 1 Ey icAlfg Ly Os eee eck ey ore 13 a : *Grasshopper sparrow-__---.-.----------------------- 3 2 agpleumartim 21 Se 11 is *Brown-headed cowbird. : 4 1 1 2 Rough-winged swallow. a > 6 OlimMeyaswitt 2 = =. 6 1 oy) Red-headed woodpecker. 4 nah 3 me Rrellowthroatese 2 ee ae 1 2 1 BONUS ALO Were) eee CU ee = 1 3 Greater prairie chicken 4 = =< ellow-billed cuckoo. 1 =o 2 _ Sango WawKe a Pe f ah 3 eo Mb aS Mei. 2. ee. 1 2 2 TR CONT. 2 ste es Ee ee en ene 1 2 Mintandiplowers = ie 1 Rolitttiesiwid Wow 2a 1 Wommon. crow... 1 oY Polokwane Se Bee 1 : Bingiandsoriole: {el ee 1 bv suet 0a A ee etree ees Sec i 1 SD SRG| soe eee ee : ao Bltankesparrow2 38 ee a + 23 Winidentified bird 1... ome cae lene 1 3 1 2 Total birds per 100 acres. WEE? 77 58 | 66 82 64 oy Wem ee Number-of species=...... 11 1 Zt Ey WG 15 13: phe 408 1905, wheat land increased to over +,000,- 000 acres in 1919 and then decreased to an average of 1,500,000 per year in the period 1940-1950 (Ross & Case 1956: 70). This crop in Illinois is grown mainly in the southern and central zones, and vir- tually all of the 773 acres of wheat fields censused for birds represented these zones. At the time censusing started each year, the wheat plants were 1.5-2 feet tall, green, and headed out. The plants ripened during June and July and were cut in July and August. Ripe wheat would ap- pear to be an inhospitably warm habitat for birds. Wheat fields were found to be a rela- tively poor habitat for birds in summer, figs. 22-24, supporting populations slight- ly higher than those in the crops of corn and beans. Basic statistical data for years in which the largest acreages were cen- sused are presented in table 11. For these years the number of birds per acre in wheat fields ranged from 0.6 to 0.8, in southern Illinois. Breeding species usu- ally comprised one-fourth to one-half of the total population in wheat fields and varied from 0.1 to 0.3 bird per acre. The I~Linois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 data, though meager, suggest that the den- sity of wheat field populations was about the same in the central and southern zones and in the two census periods. At least 33 species of birds were iden- tified in wheat fields in summer, table 12. No species was reported in all years in both the central and southern zones, but the mourning dove was a common species in all years in the southern zone. In both zones, the eastern meadowlark and the dickcissel were recorded with very high frequency. These species, the redwinged blackbird, and the grasshopper sparrow nested in wheat fields at least in the early part of the summer, though wheat is prob- ably poor nesting habitat for any species. In the central zone, the dickcissel used this habitat more in 1957-1958 than in 1907-1909, table 12; in the southern zone, the redwinged blackbird was the predom- inant species on wheat land at the time of the second survey, fig. 15. Pastures (Summer) The censuses indicated a marked reduc- tion in pasture acreage between 1909 and 1957, particularly in the central and Fig. 16.—Pastureland with trees. The acreage of savanna-like habitats of this kind was greatly reduced between 1909 and 1957. The reduction contributed importantly to a loss of species variety in the avifauna of many parts of Illinois. Photograph taken near Ogden, Illinois, May 28, 1907, by Alfred O. Gross. t + a October, 1963 GraBeR & GRABER: southern zones. In summers of the two study periods, 2,087 acres of pasture were censused for birds, only one-fourth of this total in 1957-1958. We estimated that the area of nonwoodland pasture declined from about 6,100,000 acres in 1907 to 2,000,000 in 1957. The pastures referred to in this report were virtually all stands of bluegrass (Poa pratensis), some with scattered low Birp POPULATIONS IN ILLINOIS 409 in the central zone. Bird population den- sities were highest in the central and northern zones and tended to be higher in the second census period than in the first. A clearer picture of the pasture popu- lations and their variations is obtained if only known breeding species are consid- ered, tables 13 and 14 and fig. 17. The average number of breeding birds per acre of pasture in the various censuses ranged Table 13.—Statistical data on summer bird populations in Illinois pastures as determined by strip censuses in the three zones. Data are (1) from all pastures censused and (2) from sample areas (each 5 acres or more) in these fields. The data from sample areas are for breeding species only. SAMPLE AREAS ALL PASTURES CENSUSED ZONE Birds Per Acre AND N YEAR : eats Acres All pie ber Species Only Northern 1110) Ee as 193 Ze, 0.8 7 1) Cy aes 147 Zk 1.3 12 IE) (ee 132 25S 1.4 13 Central iL ESN OV facet ele 287 1.5 0.5 12 OO Oe 155 D2, 0.9 7 1907-1909 442 ae Lx 19 OS) fen tere 54 2.9 1.2 6 ND Bik oe 118 22 0.9 7 1957-1958_.| 172 ai cane 13 Southern 119) 0) 7 eee a 601 1.3 0.5 21 OOO) Sa 281 1.6 0.7 11 SS yj eee ni 72 135) 0.8 6 MOS Sess 48 2.1 12 7 1957-1958. | 120 a un 13 | Birds Per Acre (Breeding Species Only) Range |Mean Standard Standard} Mean + Deviation Error 2B SB - 0.1—-1.4 0.6 0.5 0.2 0.2-1.0 0.7—2.3 1.4 0.5 0.1 1.2—1.6 0.1-2.9 1.0 0.9 0.3 0.4-1.6 0.1-0.9 0.5 0.3-1.1 0.6 a =m ie 0.1-1.1 0.6 0.3 0.1 0.4-0.8 0.7—1.7 12 Se 0.2—1.3 0.9 Ee Dat ast 0.2—1.7 1.0 0.4 0.1 0.8—1.2 0.1-1.6 0.5 0.3 0.2 0.1-0.9 0.3-1.1 0.7 0.2 0.1 0.5—0.9 0.3-1.5 ibaa 0.5-1.9 tat pe | we ses 0.3-1.9 1.1 0.5 0.1 0.9-1.3 woody plants (6 inches—2 feet high) and a few with isolated trees, fig. 16. The grass cover was dense, usually 4-10 inches high and forming a continuous mat, which was grazed by cattle or, rarely, by sheep. The characteristics of bluegrass pastures as bird habitats probably have not changed greatly in the present century. Both quantitatively and qualitatively, pasture was shown to be a rich open-coun- try habitat for birds, figs. 22-24 and ta- bles 13 and 14. Average summer densities of birds (all species) per acre in pasture for the two census periods and the three zones of the state had a range of 1.3—2.9, table 13. Maximum annual variations in consecutive census years were 1.5—2.2 (1907-1909) and 2.9-2.2 (1957-1958), from 0.5 to 1.4, table 13. The highest mean population density for 1907-1909 was 0.9 bird per acre and the lowest for 1957-1958 was 0.8. The differences be- tween mean population densities for the two study periods were consistent for all three zones of the state, fig. 17. It seems probable that population densities of breeding birds in Illinois pastures in- creased, possibly even doubled, during the half century between the two study periods. At least 76 species of birds were found in pastures, table 14, of which only 7 (eastern meadowlark, house sparrow, grackle, redwinged blackbird, field spar- row, cowbird, and dickcissel) were re- ported in all census summers of the two 410 Intrnoris NaTuRAL History SuRVEY BULLETIN Vol. 28, Art. 3 Table 14.—Summer avifauna in Illinois pastures (birds per 100 acres) as determined by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused; + indicates less than 1 bird per 100 acres; * indicates breeding species in this habitat. NORTHERN ZONE | CENTRAL ZONE SOUTHERN ZONE SPECIES 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (193) | (147) | (132) | (287) | (155) | (54) | (118) | (601) | (281) | (72) | (48) *Meadowlark (species?) _. 14 35 39 19 21 31 44 20 +4 58 56 House sparrow _. ey 9 11 31 30 52 93 20 7 + 27 Common grackle_ | 28 8 16 15 21 44 1 8 8 11 15 *Redwinged black- DTS es Fs\\ae hs 29 52 1 14 7 10 4 7 4 8 *Field sparrow —_ 6 3 2 5 3 20 19 10 5 11 33 *Brown-headed cowbird 23 6 4 2 31 15 1 2 5 5 8 Barn swallow __. 7 9 11 2 3 7 2 + 7 33 Yellow-shafted Hicker.) ts feajes be 3 3 8 15 x 2 3 4 Dae Robin es ee oe |? 1 1 10 9 2 2 5 4 2 *Grasshopper sparrow___...._... 3 ii 5 4 2 20 4 2 a 3 = Stable eee aes | nee! 13 28 7 1 5 4 *Savannah spar- WDA one ae ee lat NS 6 24 17 1 Tye oS *Dickcissel._._..______ 3 1 1 3 4 15 5 4 1 1 2 Brown thrasher___ 3 1 4 12 1 3 9 3 4 Mourning dove__ 2 4 1 4 7 4 2 5 9 3 American gold- fch ye 2 6 7 Lik 13 4 1 1 2 *Bobolink___.. 5 11 17 aS 1 ae *Bobwhite_ 1 1 5 2 4 7 3 8 "Horned larkean= 2, 6 1 8 13 2 4 Eastern king- indies cia ees 5 Ti 4 4 1 ee 2 4 eae e Eastern bluebird__ 1 3 at 1 1 2 1 2 5 8 Blue jay — 2 1 2 1 3 oy 2 3 4 3 ia Red-headed woodpecker____ 3 1 7 4 sure 2 + a. Common crow___. 6 2 6 2 1 1 oe 2a Orchard oriole __ ac ane sau 4 3 4 1 4 *Killdeer we 1 5 1 3 2 + 1 Z Chimney swift __ 2 sess Si 2 5 1 =F 4 *Vesper sparrow. | 3 J 4 em se ooo we cae Indigo bunting ss 1 fe: ue ais 1 2 be + 4 4 *Song sparrow ____ ix 4 2 1 3 2, SG Mockingbird set as ee a2 wa 4 2 4 1 F\.. Yellow-billed Clickoo.y | 1 1 es i 3 4 ee + 1 us *Lark sparrow ___ | - de ras 1 1 2 5 1 ' *Upland plover... | 3 2 aon 3 ross Ese + 1 3 ’ House wren ____ | 6 y i 1 ‘i Baltimore oriole + 1 = 1 2 4 aod 3 Cardinal = we ae 24 he ao 4 ee — 3 3 Sparrow hawk ____ cb een wi Ne 1 4 1 28 Es Cathird ae hitag 1 itt : 1 ae 1 i Bank swallow __ 4 re 1 1 Loggerhead | 15 Oe) peered A ea 1 1 3 ae Chipping sparrow 3 Ay ETN ip gael ys vi 1 Yellowthroat —__ bts ioe, ue if 1 1 2 - Porpleimartine 2.) 22 ms 1 1 2 ee. Bewick’s wren le at 3 October, 1963 GrapeR & Graper: Birp PopuLations IN ILLINOIS 411 studies and in all zones of the state. Sev- The meadowlarks appeared to increase enteen species of birds were believed to their population densities between 1909 breed in pastures, table 14. and 1957, particularly in the northern and Table 14.—Continued NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE SPECIES 1909 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 | 1907 | 1909 | 1957 j; 1958 (193) | (147) | (132) | (287) | (155) | (54) | (118) | (601) | (281) | (72) (48) Tree swallow. | = 1 at = 2 ane we Arg ae 4 ead Green heron... | we bes 1 1 me ~ ae a a Turkey vulture _ : [ss a a ues a “ 2 - wi Great crested fly- eALCINGT ee oe = be ve 1 ae as ta es, Eastern phoebe_ ae a as See 2 a ee hese Chickadee (species?) = = Se oe 2 Bs + ee eee = Tufted titmouse _~ _— aoe Low. eee ee 2 _ Ax, 8 22 Red-tailed hawk _ 1 = 1 = = = = -— a == Rough-winged | swallow............- ers 1 au a = ie 1 zee =e = si Bell’s vireo_. =e ae = re 2 = eee = a ave Rufous-sided towhee.. £ aes 1 a 1 ae! Carolina wren __ | ae =e zie aN) = ae = + — 1 tee! Spotted sandpiper | nis 1 + a ae & ws se Le Be! Common night- |S iod eeae ee _ 1 s Red-bellied wood- peckeros: 2/21: | a= 1 Eastern wood ENC Cees 1 Pee us es a a ane a BN ee Red-eyed vireo _ 1 ae sui aA ee oats “a = a ce is Yellow-breasted | (Cl vig tae eee eh = aa, ee ARTE in = + 1 Lal Ure © Black-crowned | | night heron ___ 1 Ee ic a. ao ae oe i cs 2 Ul irat *Greater prairie chicken 22-2 1 ie =e uae a ed tas ae am POEID) ive a Ring-necked | pheasant ae 1 iat =e 8 He = ae ey 5 eee = Belted kingfisher_ _— ere ee! 1 White-breasted | nuthatch z 1 | Brewer’s black- | lax rto Les PU eae 1 : 2 Marsh hawk =| 5 American wood- | COC Kes ee 23 te = Me 8 | ae en + we bets Black-billed | cuckoo... we er hs ee + ae = Meters af ae aw Hairy woodpecker. Ean Aes us a ae. ae Me as es me Downy wood- Beemer oct ae BBY p oe tte = a abe a. + = a eS Smmmertantger. | — |. | rs ae ee Ba ees = ae te ua *Bachman’s spar- | | row | oe Seal ial ese sug Poeiee | Hawk (species?) _- ake + Jey iasmeteen cs eed Unidentified bird 3 AOS. 1 3 2 Taal ewe’ 2A a 1 Total birds per | | | | 100 acres SUF NE 2LO aes yl CIO eae | 2OF- a 228 oN heee~ | Loe VEST ed NMumber-of species | 42 | 32 | 25 | 35 | 36 | 28 | 28 | 49 | 42 | 26 | 15 412 te-—_——}» NORTHERN ZONE 1907-1909 1957-1958 - =. - CENTRAL ZONE 1907-1909 1957-1958 +: > -.-- SOUTHERN ZONE 1957-1958 >: > + STATE OF ILLINOIS 1957-1958 ON 2345 1.0 15 2.0 2.5 3.0 BIROS PER ACRE Fig. 17.—Populations of breeding species of birds censused in Illinois pastures in 1907-1909 and 1957-1958. The vertical line through each black rectangle indicates the mean, each open box one standard deviation on either side of the mean, each black rectangle two standard errors on either side of the mean, and each set of arrows the range. central Illinois zones, as field sparrows did in the central and southern zones, table 14 and fig. 18. Other species showing in- creases both in relative rank and actual density were the redwinged blackbird (northern zone) and the savannah spar- row (northern zone), fig. 18 and table 14. Ungrazed Grasslands (Summer) The acreage of ungrazed grasslands in Illinois is relatively small. We encoun- 50 MEADOWLARK REDWINGED SAVANNAH BLACKBIRD SPARROW Fig. 18.—Relative abundance of common species of birds censused in pastureland of the northern, central, and southern zones of Illinois in the summers of 1907, 1909, 1957, and 1958. Only those species are included that showed changes in relative abundance (per cent of all birds counted in pastureland) between 1909 and 1957. ILtinoris NATURAL History SurVEY BULLETIN f=) 40 5 °o A z ish mot FY Zz ; \ PASTURELAND x i » NORTHERN ZONE ---- ro) i CENTRAL ZONE —— 20 SOUTHERN ZONE --.-.-- in i P e ta i \ . a 10 } ‘ 5 J i Was i i Vo Aa : ye Bee . a 0709 57 58 0709 5758 0709 5758 0709 5758 0709 5758 070 STARLING Vol. 28, Art. 3 tered the habitat principally along railroad rights-of-way and road edges. We esti- mated that the area of this habitat de- clined from about 330,000 acres in 1907 to 218,000 in 1957. Excluding roadside grass, 165 acres of this habitat were covy- ered during summers of the two census periods in the nothern and southern zones of Illinois. As a bird habitat, the ungrazed grass- lands were closely allied to pastures and fallow fields; woody plants were almost completely lacking in the ungrazed grass- lands. The cover of grasses and forbs in the ungrazed grasslands was taller (about 2-3 feet tall) than that in pastures and it was more dense. Summer bird populations in ungrazed grasslands (excluding roadside grass) were comparable to those in other grass- land habitats, with densities varying from approximately 1.2 to 3.9 birds per acre (119 to 386 birds per 100 acres, table 15) ; the densities in ungrazed grasslands were higher in the northern zone than in the southern zone. At least 29 species of birds were iden- tified in ungrazed grasslands in summer, table 15. Species common in this habitat were the redwinged blackbird and the eastern and western meadowlarks. Ny, : a ar ge 00°F -.0-@ = - 9 5758 0709 5758 0709 5758 BARN GOLDFINCH HOUSE SWALLOW SPARROW FIELD SPARROW October, 1963 Graper & GraBerR: Bird POPULATIONS IN ILLINOIS 413 Table 15——Summer avifauna in Illinois ungrazed grasslands (birds per 100 acres) as de- termined by strip censuses in two zones (open stands only; no roadside or edge grass areas included in this table). Figures in parentheses indicate numbers of acres censused; * indicates breeding species in this habitat. NORTHERN ZONE SOUTHERN ZONE EO 1909 | 1957 | 1958 | 1907 | 1957 | 1958 (15) (10) (49) (33) (20) | (38) | *Meadowlark (species?) 47 ou 66 GF) 405 37 gheavwiieed blackbind. = 22 88 19 41 36 30 fom PACUInNIR AON Ga ee a fe 7 98 12 13 Hipnetreral: eis (ee Re eT ee ee s8 we 113 aes 13 Commontorackle 2.0 ee 20 9 ae 15 21 eG) O@ LNT Se 5 eS On i a eS 54 = oe = ib zeta) Gaon llll (vy eee ele 27 9 2 13 BINVenUpESpAmnO Wye ee 38 ae = NTE LCS DT OVW in eee a ae me 25 | 5 peieiican patdnorh = 19 10 SABUEUES (Sy DDPETET ECG ll eg 20 9 ze ee *Grasshopper sparrow. ae 4 15 5 Brown-headed cowbird_..._____ 19 2 OUSEsS Dat Ow see ee Se ea 4+ 9 5 ~ SD oiicel RYCHRSSVe ce he ar = 4 6 5 3 LRA DLSW PL 5 An el ee ea 7 9 a “LBS VON ATG ee ee Be: 6 3 3 TESVAUYS: SJE srs A Se ee rd 9 ae 3 PP OIATIOMT CROW eee ewe wie NS ek Sy 10 Wellow-shatted flicker= 2 7 2 = ManelieOm anit ee ee ee te ed Be a 5 3 Bevaimahisparrow 8 8 --- KGommonnerte tse va = ee pe) PMinenicanmed starts. 2. a SL = 54 Red-headed woodpecker... 3 bin Ps Stalin eee tS Seo Pe ee ee a | 3 SH decrmeenne tke. se eet SNE oe = | 2 EAT K ASD saee ese Pl, we ee. 2 Short-pilledsmansh wren. bes 2 Winiidentiiedsbind 2a ea 2 7 38 TOE ae ek 5 aa ital birds per 100 acres | 284 | 178 SSO |) S1SO8 NL AsOT) hl achee Mrminet: Of species | en 9 17 ei Ae 11 Fallow Fields (Summer) As we define the habitat, fallow fields are fields that have been cultivated and then left unused for a year or longer. Such fields support a variety of weeds and grasses that form a fairly dense cover to a height of 2-4 feet. Small shrubs may be found scattered in the older fallow fields, but woody plants are not a dominant fea- ture of the habitat. As a bird habitat, fal- low land probably bears closest resem- blance to pasture or ungrazed grassland. Agricultural census figures and our own census data indicate that the area of fallow land in Illinois declined from about 1,- 500,000 acres in 1909 to 1,000,000 in 1957. Logically, acreage of fallow lands should diminish as a swelling human pop- ulation increases the demand for culti- vated land. In Illinois, largest acreages of this habitat were found in the southern zone; smallest acreages were in the in- tensively cultivated area of east central Illinois. In the study periods, 682 acres of fallow land were censused, table 3. Population levels of birds in fallow fields in the southern zone did not change greatly in the half century after 1909, table 16. As bird habitat, the fallow land censused was rich in numbers and species, being about comparable to pastureland. The numbers of birds per acre for all cen- sus summers in the southern zone ranged from 1.3 to 1.7. Among the breeding spe- Vol. 28, Art. 3 414 Ittinois NaruraAt History SurRVEY BULLETIN Table 16.—Statistical data on summer bird populations in Illinois fallow fields as de- termined by strip censuses in the southern zone. Data are (1) from all fallow fields censused in this zone and (2) from sample areas (each 10 acres or more) in these fields. The data from sample areas are for breeding species only. ALL FALLOW FIELDS SAMPLE AREAS CENSUSED Birds Per Acre Birds Per Acre (Breeding Species) YEAR oe a —. — Breeding) Numb es S All Species unk) Observed Range Mean pecies Only 1907 138 | rs 0. 4+ 0.1-0.5 | 0.3 1909 ; 181 1-5 0. 7 0.2—1.4 0.8 1957 a ee bas Ge 0.3-1.4 0.8 1958 hl Le? 1 2 0.8-0.9 0.8 fief AOR ele| 1) ely pendent lar |-PLOWED | FALLOW_| 18 NUMBER OF COMMON SPECIES fo) QGQQAVQ__QEAA?|VVN MG GGUW{ Bg MG T BGG QGG 07 O9 07 O39 CENTR 1909 57 58 NORTHERN a PN Fig. 19—Numbers of common bird species (those comprising 85 per cent of the popula- © 8 QQ GGG SOUTHERN AKQDB™KB WW 90 QQ GMM QS L,''™7 MM GG QAI fitftts 4 0709 5758 SOUTHERN SAAN 07 09 5 SOUTHERN 5 @ @ tion) in three open-field habitats of Illinois in 1907-1909 and 1957-1958. cies, which usually constituted at least one-half of the total population, the num- bers ranged from 0.5 to 1.1 birds per acre. At least 50 species of birds were iden- tified in this habitat in summer in the three zones of Illinois. Only the eastern mead- owlark and the mourning dove were re- corded in all zones in all census years, table 17. The redwinged blackbird, field sparrow, and grackle occurred with high frequency in this habitat. In the southern zone, population increases were noted in this habitat for the mourning dove, red- winged blackbird, dickcissel, and grackle. The loss of variety in avifauna (after 1909), a loss that characterized other open-field habitats, was apparent also in the fallow field avifauna, fig. 19. Mixed Hayfields (Summer) To point out possible differences in the bird populations of various types of hay crops, we segregated data on hayfields of mixed grasses and legumes (called mixed hay) from those of the relatively pure stands of alfalfa, red clover, and sweet —— October, 1963 Graper & GRABER: Birp POPULATIONS IN ILLINOIS 415 Table -17Summer avifauna in Illinois fallow fields (birds per 100 acres) as determined by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused ; * indicates breeding species in this habitat. Notary |e ore SourHeRN ZONE SPECIES | IIA || UME pe Ie yy 1907 1909 1957 1958 (26) (22) (25) (138) | (181) | (153) (77) pMionnnine dove... 2. A eel 56 1H) yf all 38 21 *Redwinged blackbird 34 41 60 5 22 2 *Meadowlark (species?) 42 41 12 15 46 16 10 BbeKersse leew = ‘ oe 116 es 9 AS 5 iI milounedetankee= <2 Poe s 81 8 oe ba Ms ae: ommonotackle 288 8 18 * 6 2 10 35 Binelaisparrow= =e ke 27 a 8 9 8 12 12 LGHISEYSDATTO Ws ae 20 26 8 i 8 American goldfinch__._.__________.. a 135 eI 16 11 oy 6 3 iadioo buntime — = es 11 ey 12 1 1 10 1 Basten kime bird 2 = 13 6 6 1 Browmnpthrasher. 2 11 cs as 1 4 1 gleaLkisparrow. 2 ae 4 8 2 3 aa mavellowvthttoat 8 te a ae oe as 1 3 1 10 *Grasshopper sparrow... ved a 8 ah 2 = 4 *Brown-headed cowbird ae 4 ae 1 2 5 1 Barn swallow ec a SN ae = 4 3 5 (Coroner ha 2 Se a ae eee he re oe ny 2 1 9 Wrehanduomole 2-2) 4 aS a2 3 3 1 Hl BeIStenMmanlieninde: ee =" £N ae 4 3 oe oe | Yellow-headed blackbird. ne. 9 ys! ee ce 22 Fa * TYG) ayy] cite Se Sh tea 3 D 3 ba Yellow-shafted flicker. nS 4. are 2 2 e Machine binds 2 ie Ce 2a, Py ie 3 5 Rees fia panne eee eee EE 4 4 Se Mimlanduplowersc= 29 ie = 8 ts Lak ESE copy clive te tas a he “es a 4 1 1 Bebe CUCKeS SUU eT a en ae Shs oe 4 1 ay @hummeyrswitt = = oe 2 1 1 Ring-necked pheasant... 4 on om ass Red-headed woodpecker aes : 72 aes 4 —_ E Rough-winged swallow : Ene val eo oe 3 = 4 Savanuah Sparrow =. = 2 4 rhe ed a AGO OM CLOW = ae Pak ett 1 2 Peg) calla 25 ak orate an ee ees ae = ee 3 tc Sparrow hawk uptesta ike ae bet Z uGplesmartin 98-5» 7. wa ans = 1 1 Loggerhead shrike = i = mes 1 1 a Yeilow-breasted chat. ae ‘a fee ~~ 1 1 LNs ero eee 22 ee ee nes aa as 1 a = Yellow-billed cuckoo <2 ae aa! 1 - Common nighthawk ue Re 3 a 1 Downy woodpecker Je wee, es 1 Great crested flycatcher___________. an at ee 1 Wltitsswallow=2 2.02 = ad MS Be 1 ena -VWLell 2 i. r a» 1 sn Rufous-sided towhee_ sta Lie ve sees 1 *Bachman’s sparrow._.._...._--_.___ =, af, ne oa 1 Chipping sparrow —- ee ar awk (species?) 2. 1 ae Mridentified bird. te eos 4 es 1 a, 7 5 Total birds per 100 acres 160 Wii \) Bi8i0) 128 149 | 152 172 Number of species ec Pe S es 13 Ef Daeg | PON © Ble Nd 16 +16 clover. The present account concerns mixed hay. During the two study periods, 1,212 acres of this habitat were censused in summer, less than 400 acres of it in 1957-1958, table 3. The strip census data and published ag- ricultural records indicate that the total acreage of mixed hay in Illinois (over 2,- 500,000 acres) was about the same in 1907-1909 as in 1957-1958; the mixed hay acreage declined in the north and in- creased in the south. Mixed hay usually forms a dense cover 2 to 3 feet in height at maturity and is generally composed of various mixtures of grasses (timothy, brome, and wild grasses) and legumes (red clover, sweet clover, and alfalfa). As a bird habitat, mixed hay was fairly rich in species and very rich in numbers of birds, figs. 22-24 and tables 18 and 19. At least 14 species of birds were found to nest in this habitat, table 19. As fig. 5 shows, field-to-field variation of bird pop- ulations in this habitat was high. Average densities of birds (all species) per acre in mixed hayfields in summer ranged from 1.1 to 8.2 birds per acre; the numbers of birds per acre in successive census years in one zone ranged from 1.8 in 1957 to 8.2 in 1958, in the central zone, table 18. I~Linors NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 Such high variability and the relatively small samples in the later census period make conclusions tenuous, but bird popu- lations in northern zone hayfields ap- peared to be conspicuously higher in 1957— 1958 than in 1909. Average densities of breeding-bird popu- lations in mixed hayfields ranged from 0.5 to 7.1 birds per acre, table 18. These pop- ulations were usually highest in northern Illinois, and almost invariably they were higher in the later than in the early years. The numbers of breeding birds per acre in 1907-1909 ranged from 0.5 to 1.4; in 1957-1958 the range was from 0.8 to 7.1, table 18. This apparent increase in population density between 1909 and 1958 may be attributable to a few species. Of the 57 or more species found in summer hayfields, table 19, only the eastern meadowlark was reported in all census years and in all zones, though the redwinged blackbird, dickcissel, and grasshopper sparrow were reported with very high frequency. Com- mon hayfield birds are listed in tables 20, 21, and 22. In the hayfield fauna, the meadowlarks were found to be increas- ingly important from northern to southern latitudes in 1907-1909, as well as in re- cent census years. In northern Illinois, Table 18.—Statistical data on summer bird populations in mixed hayfields of Illinois as determined by strip censuses in the three zones. Data are (1) from all mixed hayfields censused and (2) from sample areas (each 4 acres or more) in these fields. The data from sample areas are for breeding species only. SAMPLE AREAS ALL Mixep HAYFIELDS ZONE Birds Per Acre AND YEAR | Acres | | ; Num- At pitas. ber 3 pecies Species Only Northern i 2) SE et tea lj 2.3 1.3 Tf 1957. | 941 4.0 3.5 ‘4 1958 30 6.2 4.2 2 Central ESO] 2 Le 1 ii 2 oa + z Horned lark 3 ws = 2 5 2 *Short-billed marsh wren_____ Ae ED 10 eet ae ed is sks ce Se aon Yellowthroat____ cz 2 a ais 1 wo gad. 2 1 fad 4 *Vesper sparrow _ 3 3 3 as = me es ent a ss Field sparrow. | 1 ae se a 1 os na 3 4 Common night- | leit] ) 1958 (32) (14) | (23) | (67) | (93) | (66) (19) ie oun 44 TAS) 15 $1 231 49 70 105 69 76 30 47 108 70 13 45 3 14 10 6 42 30 54 40 59 16 28 14 158 15 9 See, 10 35 118 1 oe 8 131 ee 7 9 13 cud aa 18 21 22 4 11 3 18 =e 9 12 9 46 (Aydt em tp Sti a igo ies ea eee 14 = 4 Le 5 26 9 42 3 ee 3 1 am oe sats 1 3 21 1 1 15 14 iF 1 1 pe ae 1 es =i 31 4+ 3! 1 PAL rape 3 Sea ae 5 aes pat z =, 26 Pat 1 2 14 1 3 pa ae zat asd 9 1 10 14 aS aie res 3 ete 3 a8e - 2 + 1 12 ras 1 3 5 3 aa 1 3 is 1 ae 4 $ 1 1 eis 1 il ey * rae 3 =< ae 302. 385 433 555 187 263 | 428 16 | 14 1a a9 es 209 “1110 as in red clover; meadowlark populations were about the same in these two clovers. Alfalfa Fields (Summer) From about 18,000 acres in 1909, the area of Illinois land planted to alfalfa had increased to approximately 1,400,000 acres by 1957. Alfalfa forms a cover 1-2 feet high, similar to that of red clover, though not quite so dense. The first cutting in Illi- nois is about half completed by mid-June and completed by early July. Second and third cuttings may be made in August and September. Most of the alfalfa fields we censused had mature stands. 422 ILLINo1is NarurAL History SURVEY BULLETIN Table 25.—Common birds (species making up approximately 85 per cent of birds counted) in red clover fields in the southern zone of Illinois, summers, 1907 and 1957. 1907 Species Per Cent Dickrissel 0s oes a ee 41 Meadowlark (species?) ----... 23 Redwinged blackbird... 8 Grasshopper sparrow__-.-..... 6 Mourning dove____- ees Tee est oan 5 Hause sparrow" ee. 5 Bobwhite ss ies Cees, eal 5 otal percent eee O3* Number of species _____-_.---.---.--.- es 1957 Species Per Cent Redwinged blackbird...» 30 Meadowlark (species?) 22 Mourning doves =o 2. ee 17 Dickersse] sae 8S ee 11 Commonypracklen = se 5 DOTA Per CORE oe ea, See 85 Number of species______________ 5 * Five species made up 83 per cent of the birds counted. Seven species are included in this table because the last three had the same percentage. All but 9 of the 237 acres of alfalfa censused were covered in 1957-1958; the largest samples represented northern I[Ili- nols. Bird population densities in summer alfalfa fields varied from 2.1 to 4.2 birds per acre, large samples in northern IlIli- nois indicating densities of 2.1—2.2 birds per acre, table 27. These populations were notably lower than those for other hay crops (mixed hay and the clovers), figs. 22-24. The difference may be attributed largely to the redwinged blackbird popula- tion, which attained notably higher densi- ties in clover than in alfalfa fields. At least 30 species of birds were identified in alfalfa, table 28. In this habitat, the red- winged blackbird, eastern meadowlark, and dickcissel occurred in all zones in both 1957 and 1958. The breeding avifauna was almost the same as that recorded in red clover fields. Lists of common species Vol. 28, Art. 3 Table determined by strip censuses in two zones. Figures in parentheses indicate numbers of acres censused; * indicates breeding species in _ this habitat. NORTHERN ZON EF) Zone SPECIES 1057 1958 1958 (16) (10) (21) *Redwinged | | blackbird... 127 <> tse 215 *Meadowlark (species?) ivy 38 41 57 *Dickcissel_________ Weekes Be 86 House sparrow...| 70 | _. 5 Common grackle_| __ 51 24 Mourning dove... —:19 10 10 Horned lark Be Pa 38 Chimney swift ieee a. 29 Barn swallow____ 6 10 10 *Bobolink —_____ | Starling tea ae Upland plover____ \ qa ye 10 Common crow ___- cae oe 10 Brown thrasher__.. | | 10 Robin 22 | | 10 American | | goldfinch_____ |e eoe 10 Savannah | sparrow TSeggrate 10 re Field sparrow___ eee ee: 10 Song sparrow ___ 25 at ee is Brown-headed cowbird | 6 Chipping sparrow... | 6 ate Bis Lark sparrow —_. |.) == ao 5 Unidentified bird = ees 10 Total birds per | at 100 acres | 329 | 274 539 Number of species 22.2) | erOi ey 8 15 of birds in alfalfa and other types of hay z in the northern zone are shown in table 29. Marshland (Summer) The amount of prairie marshland in the = state of Illinois has been reduced since — 1909 as the demand for tillable and urban land has increased. From data presented — in a report of a U.S. Fish and Wildlife — Service wetlands survey (Shaw & Fredine 1956:7, 20-5), we calculated that there ~ were about 558,000 acres of prairie type marsh in Illinois in 1906 and only about 60,000 in 1950. 26.— Summer avifauna in Illinois ; 4 sweet clover fields (birds per 100 acres) as s CENTRAL October, 1963 Graper & GraBer: Birp PoPpuLATIONS IN ILLINOIS 423 Table 27.—Statistical data on summer bird populations in Illinois alfalfa fields as deter- mined by strip censuses in the three zones. Data are (1) from all alfalfa fields censused and (2) from sample areas (each 4 acres or more) in these fields. ALL ALFALFA FIELDS SAMPLE AREAS ZONE Birds Per Acre Birds Per Acre (Breeding Species Only) AND YEAR Breedin Hone aes Al otiaee ber | ange |Mean| Standard |Standard | Mean + Species | “PECs ge wean! Deviation | Error 2-SsE- Only Northern | | aie eres 75 2.2 Nee) 7 0.2—4.4 1S 1.4 0.5 0.5-2.5 i a 63 al ae V2 oe Ce be ive ea Central | | MOS fe 28 | 4.2 itil 3 0.9-4.7 2.5 ae past wtns Southern HOS =o | 40 Zi 1.2 By We (0S ley sleil 0.4 0.2 0.7-1.5 Table 28.—Summer avifauna in Illinois alfalfa fields (birds per 100 acres) as determined by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused; * indicates breeding species in this habitat. | CENTRAL ZONE | SOUTHERN ZONE NorTHERN ZONE SPECIES 1957 | 1958 | 1957 | 1958 | 1957 | 1958 (75) | (63) | (281 Ga), | Cay tier BBLS afibgs || aee i mea ial | | Metnonsediblackbird. 4 85 | 67 | 82 8 303 20 Mumeadowlatk (species?) i eee Jaan en i) 21 23 22 Ae wie Plepipioggal J ei ies 2 a a PAG =] 6 165 23 oar ee 5 Ditlhehgg sa SS eS eee | i | 2 32 23 76 28 ceil litnyse ie DEE ee | SG pela 25 99 it 1 BUMISERS VAIL OWE ee a SN | 3 | 3 77 za 22 5 Grasshopper sparrow... 4”) 3 28 C3 allt grea aa: pear tiNGS lien eee ee ee a) 31 60 Mer: a so) tape Eines wallow = nee Pee 7 2 18 ee a ge 48 Maran ONDUntin eee as eS, Eh cys 3 = | - 22 BLS Bepmretiine dove 6. ee 8 3 3 8 2 Ring-necked pheasant... = aa rey 23 te Si (taeareeere Mpland plover... _. is 6 a ce Aha, LAPON Dice On 7 Zs || gt earl 5 MESDEL SParlOWw 2 ee : Se | 3 3 SO Np ee zt Killdeer __ a Re ee ON ed 1 Z pe =e ees AO Meeiovithroatee ne OR a ee is eg Mo ee es ue a eBrown-headed cowbird__.____________--_________ 3 a ae BN ermee =s Tanai feb er meNbs nro ade oa Nas as ooh sa a 11 ~s Beavanilahesparnow. 4 5 wes =e oo Set Dennmiaieerackion = 0 ' 5 te = ue Ba 2 577TH a ee 3 as ane @ebastern kingbird..._= See: nS = — 3 JE DT IEL CH DIPaIS) NS ee ee ee eee |) ar 3 Fog) byim 2 RS Dae ee ee 3 cae: Be , LUTE Sy A 9 Cee ee ee Brinnon ChOvye ys. ee 2 a he ek Le eee ty e | Bree ES |) aE ROWe = era a 2 | Wellow-shafted flicker... es 1 Pordecican eoldtinceh 1 | RTCA (Ye Oy (eee ee es | 1 vz = — zs a Miitdentitied) unde. ne et oS es Pe 3 9 = Trew oa a 5 otal birds per 100 acres_.. | 220.05) <206- \ 420 260 | 467 | 209 Number of species __ Jen RE ao a? MSS a 20 14 14 | Sie Teel ele 424 ILLINoIs NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 Table 29——Common birds (species making up approximately 85 per cent of birds counted in strip censuses) in different types of hay crops in the northern zone of IIlinois, summers, 1957 and 1958 (combined data). Mixep Hay RED CLOVER ALFALFA 2 : A P Species ia Species hee Species Cent Redwinged blackbird 46 |Redwinged blackbird___ 33 | Redwinged blackbird 30 Banolink> 23 2 = soa 14> {Bobolink} 22-257 3 15. | Bobolink. == ae 22 Meadowlark (species?) _ 8 | Meadowlark (species?)_| 11 | Meadowlark (species?)_| 21 Common grackle_.__ 8.~| Dicketsselie 8 | Horned lark 5 Savannah sparrow______ 5 | Vesper sparrow___._______. 6 | Mourning dove________ 3 Brown-headed cowbird__ 2 | Savannah sparrow. 5 | Vesper sparrow 3 Mourning dove... 2 | House sparrow-__ 4 Starling ese ee 4 Rota Percent 2 eo 85 | Total per cent___.__._..__. 86 | Total per cent... 84 Number of species. 7 | Number of species 8 | Number of species. 6 The marshes censused for our report were low wetlands in pastures of north- eastern Illinois. Vegetation consisted of sedges and cattails at the margins of open water. Only small areas of this habitat were censused ; the total area censused was 155 acres, most of it in the summers of 1957 and 1958, table 3. The associated avifauna, as well as the marshland habitat, was distinctive: a very high bird population and a variety of spe- cies. In northern Illinois, the density of the bird population in marsh exceeded that in any other habitat but urban resi- dential area. Marshland population densi- ties varied from 4.9 to 7.4 birds per acre (488 birds per 100 acres in 1957 and 742 birds per 100 acres in 1909, table 30). Despite the small acreage covered, at least +1 species of birds were identified in marshes, table 30. At least 18 of these nested in the habitat; three additional spe- cies, the bobolink and the two meadow- larks, probably nested at the dry margins of marshland. Judged from the avifauna, the summer marsh habitat covered in 1909 was not strictly comparable to that censused in 1957-1958, though the commonest spe- cies for both periods were the redwinged blackbird and the grackle, table 30. Shrub-Grown Areas (Summer) Throughout Illinois, but especially ‘in southern Illinois, there are small scattered tracts of shrub-grown grassland or “waste- land.” The dominant features of the habi- tat are deciduous shrubs under 10 feet in height and intermittent open areas of grass and weeds. In both surveys, this habitat was often found at the margins of woods. It was similar in some respects to fallow fields and pastures but differed from them in having a large amount of shrub cover. The acreage of this habitat was small compared to that of open-field areas and forest; only 267 acres of shrub- grown areas were censused, principally in 1957-1958 in southern Illinois. We esti- mated that there were about 500,000 acres of nonurban shrub-grown habitat in Illi- nois in 1907-1909 and in 1957-1958. In terms of both numbers of birds and numbers of species, this was probably the richest summer habitat in the state, table 31. Summer population densities for large samples (30 acres or more) of nonurban shrub-grown areas varied from 2.3 to 4.4 birds per acre (average: 3.4). We have insufficient data to determine whether there was a change in population density for this habitat in the half century fol- lowing 1909. At least 74 species of birds were identi- fied in shrub-grown areas in summer, table 31; only 2, field sparrow and goldfinch, were found in all census years in all zones. Other species that occurred with high fre- quency were the indigo bunting, mourn- yellow- ing dove, cowbird, cardinal, breasted chat, redwinged blackbird, grack- le, towhee, brown thrasher, and catbird, tables 31-33. 436 Lolpet’y October, 1963 Graber & GRABER: In this habitat, the population density varied considerably from 1957 to 1958, table 31. That there was qualitative vari- ation from zone to zone is shown in the lists of common birds, tables 32 and 33. In 1957-1958, the redwinged blackbird was the most numerous species in the northern zone, the field sparrow in the central zone, Biro PopuLaTions IN ILLINOIS 425 and the indigo bunting in the southern zone. Edge shrub habitat, such as fencerow and roadside, had very high bird popula- tions. The 45 acres of this habitat cen- sused in the state (all in 1957-1958) had a mean density of 22.3 birds per acre; 21.1 in the northern zone, 19.1 in the central, Table 30.—Summer avifauna in northern Illinois marshland (birds per 100 acres) as deter- mined by strip censuses. Figures in parentheses indicate numbers of acres censused; * indicates breeding species in this habitat. The acreage of marshland censused in the central and southern zones was too small to be included here. 1909 1957 1958 SPECIES (19) (29) (58) Bmeawitoed blackbird. eit ee A TAA | 494 162 226 CE Le aa a PERL Re 130 93 117 Beare Tc) icq nen eee eee des el 88 3 dee ESIZYU (HSU Se A Sree nS aa ee eae 34 55 Par FTN O ees ea SN ee ae 58 14 eellovw-headed blackbird. iad Ee 65 ME Reocinannt ny Onc ioivr ec eerie tes ae eee ee ee E A 55 ance oilled marsh wrenyo= <2. 2 a AS 14 24 “OLE: SDLOTA ONY ea ee OE a ee 5 10 10 SLE FUUNCG GR cS ao EC a a Te CI he 21 Y PUPBN a te db I a Ore 5 | she 15 Bemiieoniucodmedleetes a2. Meet 25 tee oni Bn 19 Besar loneyy AG Kan (SDE CIES i) )cce tee a ah es 10 a 9 *Killdeer___ Bae. Pere ee Ps reer NS Me cae sus 17 DPNTIRCHES ATT CII pe tyere = ere eres ce et ee ax8 7 10 Bemeeneckedenneasamt one...) Se rw 14 Savannah sparrow Cr Sk Ea 2 A Ds Te BEE EN 5 7 *American bittern Se Fre ee ee ae a eee eee a 10 oh © LAEEISUP Voth Siero) a SS A Ta ers ee ena ae a 10 2 EAVES OGIn) (Ga) Ko TCE se ane A I pe 10 © Fr mee sD a 7 2 | *Brown-headed cowbird_..__.___=_ = Esc SL St Poh eet PLE ae2 7 2 MBPNTITe TS CAT COO ts 5 3 Be es aA er es ~~ iz Billa Mae ONES See ee Sees See we rae ee ey 3 3 LABEIEST, AVGTEOEO Late ls ee Ne ARR RF ee le Ae ana ee ee a a aa 3 2 eviallard 2 ie De eld Be eee ee eS Oe gee OLED Se 5 Pelton -billedienckoois= ss... o's 5 a2 eft: Short-billed marsh wren SpE ine ted Ae ee Ge: 3 2 Vp crimiayel (Save w (ote BOSS SI TEAS US a oa ene a ee a 3 ReESATM IS MCT ERE TO Wa eet om ne ei NN ye ee 3 SMT RRN EL CO TISIVLPD ieee eee Se | x 3 Pare tilusmtiy Crt Ch eles ee seat ee eee YS ate ae 3 Peronewmain red swallow. be 3 hes —ELERNAAK OTE, TR OR ye OE eee RA ae 13] 3 Lseiaeiein, (OVO) eyeeCa Le a eae ee a eee ee Tae iG Li. Se eA SS se Se ee ee Pe 3 ay Seuen crowned uieht heron 5 2 ges TeeuTlT ee Ewa SL So ereene A er ea e a e 2 | snemeya ules ime i ess Se A SIE oa ee ae en 2 Se fre! Vetinetis nie SINS Se a eee A eae oe ces 2 OT sree Some any Sri a eR eh ae 2 SCRUM Kant, [oe eee ct ene we 3 Binctentitreds bincdeesmnme mes memes SEN NA ge | ee as ‘ 9 Beammrinds her 100 acres! = 2 a 742 488 702 Merman nro ha neriag at. we aes Wa | 8 24 30 426 I_tinors NaTuRAL History SurRVEY BULLETIN Vol. 28, Art. 3a and 25.1 in the southern. This habitat shrubbery in the state, most of it in south- was so limited in acreage (we estimated ern Illinois) that it accounted for only a that there were about 86,000 acres of edge small part of the state population of birds. Table 31.—Summer avifauna in Illinois shrub-grown areas as determined by strip censuses in the three zones (no edge shrub included in this table). Figures in parentheses indicate num- bers of acres censused. Most of the species listed are known to nest in this habitat. NoRTHERN CENTRAL | SOUTHERN ZONE ZONE ZONE SPECIES ; 1957 | 1958 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (15) | C17) | (15). 1 (35) 7) CEE GS9 G7 ie oes Preld sparrow 2204s es ae eee es 88 Eve Men i) Gs alt 74 26 49 24 Tndigo buntwe 2 eo ae ea 7 mee 13 23 28 41 46 42 Redwinged blackbird... 167 52 eve sat 17 2 15 6 American goldfinch______.---------_------_------ 47 46 53 23 23 28 1 10 Brown-headed cowbird_--_— Ziff 35 i 23 pee 23 16 19 Cri oe mess Be ese cern ee eee 7 ae ae 11 28 33 15 19 Brow: thrasher 24 =e es eee 41 Lf 7 17 Zoe 5 4 — Yellow-breasted chat =e = 13 11 6 33 Di 8 QUE YTD yh no Maca ae Bi) eae EI eR teat Fea ee 41 23 i 17 ie 2 1 i SORTS pat rO vy eee te orate ESV eee eae: 41 35 mae 11 ae mas 2a as Mournins doves iy te Se 7 6 7 14 sy 28 10 11 Yellowthroat POD SEE Rha Sava vas OKs 20 aa ays fe) 6 36 15 6 Commonyorackle 302s 25 8 Coe aah ee 47 12 us 6 6 bls, 1 3 Savanah Sp anno yy et ee 60 Let ie eas Rufous-sided towhee_.... [ee 6 Diss 6 11 8 16 8 Red-headed woodpecker... sss ote 7 3 as 36 aH ah: BlUe Wayst ak wee C8 ie Se ae ees ate mi ie 9 17 13 4+ 1 Banks siya ayy eee ee se a oa te al 43 age Beh saat oa Chickadee:((species?)). V4 es ee ik 6 en 11 pial aN 16 Meadowlark (species?) 14 23 Ja he a 2 sea 25 astern kine bird]. wero ae ee, 20 we poll sa Oe ra st. 1 ee Btted tlemoUsese = toe oe Bae a fo fis Ee 6 ie 8 18 2a DICKCISSE le see ED Coe ae a, 20 acid 7 at a 5 aa Ba: Yellow-billed cuckoo.) : 7 cy oe sx 11 10 1 1 Orehardioriole seo aa ea ee ee gout ais es2 3 Bs 13 6 8 BOR yeni tea oe tae No ane ns Ee a Ey 7h 11 5 3 1 Carclinadbwren ie? tr 2a Wa es gi 6 10 7 3 Wespers panto w esas tai Tie pie Ie 20 6 ae ee ate 180) OF 7 Gee? ee A IPE ge ie RN IOs 1 ie al eae LO Sc e 6 3 11 eds) 3 ROUSE sayy Re Dee se 28 eh NS aie ees Cs Bear 14 ae ae 6 as RS 1 — Ecalls dyeatcher: ic Ve ns eae 7 6 7 azz me aK a _ Hasteconphoebess 2. ita) ee et NE, 7 me ithe ples a 8 ie 3 WVicod ithinush abn hee ery aie ee ae sat axe pial ee 8 3 6F Greaticrested flycatcher = 6. eee uae oe aes es 11 Z 3 Ee: HAStern wood (pewe e222 ree eet ere ie Lea et 6 aad 2 1 53 ce dyapaitider Owen. et OAs Geel Oy 14 Saud AS tak ae 5. jae i Baltimore soniol efi i OW ey ier eS a 14 ae ia ae an a Bee _ SEAL Rte oO Males i) IR OOM artical eat Ae a Le i aby ass 6 Wee pa a — Wehite-eyedvireo. 2 tes be, ae Asif ee" 6 2 4 1 Amenicanedstants-: 0. en) yea ine. eau ue a 11 ae a i _ Bell scvireos. ee oe Ss es |e eee be 3 4 3 Praineswatblerssevnes eran on Bhar: es 7 3s Ruby-throated hummingbird. 3 5 : 1 8 Downy woodpecker... ne 5 3 1% Howse:sparrow E 3 6 5 Red-bellied woodpecker... Ai By yes ie ae 5 Nes 3; Wommmoriverdyy 5.1 a8 Ec 2 ee ee |e, ae ia os ee nae 8 on _ Bewitksn wrens 2 so San) ge 6 2 4 Red-tatledthawk2wet 44-2 Asan eee 7 ‘t Ring-necked pheasant.) 3 1. ees 7 = October, 1963 Graper & GRABER: Birp PopuLaTions IN ILLINOIS 427 Table 31.—Continued | | NORTHERN CENTRAL | SOUTHERN ZONE ZONE ZONE SPECIES | 1957 | 1958 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (15) | (17) CERN cte(S5)0 f CLL aCe (Gey ae) erg) Lire ea ee Wh Cliff swallow__....... ees eis a 2 ached ie ey Eas eau ae ke SepeIIMeDITd Beene Ween ve Us, 6 bat i Malitinverviatb ler ee at bit, 3 aa ie 7 Say Bobolink... 558 Nice itt ere a ae i eecshopper 5 GPG OV ee Ne ae ee ji = Mellow-shafted flicker... Bal, 46 ee on : PeIOMMIAN S\SPALTOW 2 o- ue 22, B, ae 6 Swamp sparrow ed CEN has eae ne 6 = Os oe et Sparrow hawk. 2 PAP em pean ee gl Haier ibe: ae eee va 5 EME DALEOVY el a gil ogee = 3 weit {ae -_ Rerenesw allow. = ended Se a age ape Te as 1 Mockingbird ie per Ae atte: athe peed = = ou 3 zat Micah Nee at ae Warbling vireo. Vice 5a S eave metab | vant = see ee a ee bs TS ia Bemeeeravermatcatcher. =. a we ee SHA) : oe Wat Parula warbler____ Berek aT OO that ies cee i a fe aS es 3 Kentucky warbler _ sia eotees h Ek ie ots an tase os Brtuleibamagere | 50020 eS se ae me = dees 2 hoes RAE VAS WEES eee ella eee eee ASE a 2 tse Paci Bredekineisher = 2 2 eh = Zs. : Whip-poor-will. ert 3 Bet a ie. pee -, &. mA = 1 Red-eyed vireo - ; Aue nD eae Le ae at a a = Zt Ae acento Prothonotary Jon ca ee ae ae = mt as a Z2s Sa el eal Blue grosbeak ___________.. Mana Petty, alc vtie a ae Se xo me Ld a” 1 Unidentified bird Sone e OPIN os A Nah in ae 13 31 is 28 16 19 otal birds per 100 acres....__.._____..| 793 | 344 | 262 | 443 | 290 | 425 | 335 | 230 Number of species... “ato ae (Te Ye) 137-74 3 180 35: ih AG 31 ve a aes) N Table 32—Common birds ‘species making up approximately 85 per cent of birds counted in strip censuses) in shrub-grown areas in the southern zone of Illinois in four summers. | - 1907-1909 1957-1958 Species Per Cent Species | Per Cent i 7 a, = | MeSDATCOW. 14 neki onb anti pee eee 1 MPO VMNGINS oo 10 Field sparrow ade ene 1 emt eat 8 Yellow-breasted chat. a bees @emerican goldfinch... Vl Brown-headed cowbird ..._-_-- S| Beenlovythioate. 8 Gardinal ewe. Se. lee ees Peet | @ellow-breasted chat... Rufous-sided towhee_ esi Red-headed woodpecker. Mournine doves 2s) ae em ee Vellowthroat=222 2s = See”, Men dove Redwinged blackbird _ eee Brown-headed cowbird Putted titmause:2/7- 202 Soe ad Yellow-billed cuckoo Carolinachickadee.- == = =| Redwinged blackbird Oxchardionoles == Rufous-sided towhee American goldfinch. =... | Ee es 0 AE Carolimaswren.. 0-2 | Memeeiita wren) Pratnicu wet blene- sca Ste Great crested flycatcher. Te Wood thrush —_________. | menardeoriole 2 61s We Bell save oe. seas kes ee ae ee Robin FBP NNN ND www SB fb BOs +S ~ KBD DNDN BWW w fan D : | Total ie Piri fimeiee ar bbe Pein Is. member of species... ES o Cn Co *” c Total percent. = Oe ene | | Number of species petals ceare| —\ “I — oo 428 ILLINois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 Table 33.—Common birds (species making up approximately 85 per cent of birds counted in strip censuses) in shrub-grown areas in the northern and central zones of Illinois, summers, 1957-1958. NORTHERN ZONE CENTRAL ZONE Species Per Cent Species Per Cent Redwinged blackbird —.-_-__-___-- 20 | Field sparrow = Eee 33 Field spartow = 11 | American goldfinch_-____— ae 11 American goldfinch ie 8 | Bank swallow ____.—_ ___. aes 6 Sang apercawe. 26s ee 7 | Indigo bunting.) eee 5 Catbird ca ca ela Wee. 6 | Brown-headed cowbird__--.-_____ + Brown-headed cowbird___ 6 Catbird 220) 2 ee 4 Savannah sparrow__.___________ 5 Brown thrasher 2 = eee 4 Common’ prackle. 5 Yellow-breasted chat________ zis. + Brown ‘thrashers =. se ee 5 Moutning dove 3 Meadowlark (species?) —.._____-__ | 3 Eastern kingbird. == eee 2 Vesper eparrery.o2 2 coon 2 Chickadee (species?) ——_-___________ 2 Bastern kine bird 22240 Ss ee 2 | American redstart________-_______ 2 Wellowirodtes = ee ee 2 Cardinal £2) 5.2 Whigs eee 2 Dtelecr sce es ei eee ee 2 | Song sparrow. ee 2 Dota PersCeiphi 88S ia ee 8&4 | Total per cent. ee 84 Nuniber of species = Oe | 14 Number of species —----__-_____ 14 acre. We estimated that there were about 13,000 acres of hedgerows in the state in 1958. Many acres of this valuable habitat for birds have been eliminated since then. A related edge habitat, the hedgerows, also had very high populations; for the 13 acres of this habitat censused in the state, the mean density was 23.2 birds per b ee £ tis 4 : j Fig. 20.—Orchard habitat in summer. The acreage of land in orchards declined greatly between 1909 and 1957. Because orchards comprise a habitat rich in both numbers and variety of birds, the acreage change represented a definite loss to the Illinois avifauna. The photo-~ graph was taken near Thompsonville, Franklin County, in southern Illinois, June 5, 1907, by Alfred O. Gross. lle October, 1963 GraperR & GRABER: Birp POPULATIONS IN ILLINOIS 429 Orchards (Summer) This very uniform habitat is closely al- The total acreage of orchards in Illi- lied to shrubby areas. The orchards cen- nois was reduced from about 300,000 sused were mature or nearly mature pure acres in 1909 to about 31,000 in 1957. stands, most of them of either apple or Table 34.—Summer avifauna in Illinois orchards (birds per 100 acres) as determined by strip censuses in two zones. Figures in parentheses indicate numbers of acres censused. Most of the species listed are known to nest in this habitat. The acreage of orchards censused in some zones and years was too small to be included here. NORTHERN ZONE SOUTHERN ZONE Peo 1958 1907 | 1909 | 1957 | 1958 (35) (19) (26) (8) (70) BR CES DY ANSE OV eee ee EE ae 159 19 50 66 pain nO ss te Ses ee ee 3 74 30 87 39 Berea ainLo yy, sel. tele Beet ee 17 53 64 62 19 memoir edublackbird a. 2 ide 5 Lee 137 19 Brrmmionpemack| ese 2 oo ke Ne 3 63 Les a. 5] Euimericansroldfimeh 2) 2 2 os 99 ee = ah, 9 mae oe wOntolessoterate. Sg a me 47 38 12 bee os GUSTS ee eee 6 32 26 25 3 31 tee | Se send eae ee a 6 16 35) 25 ee Meera OBLDUIM ta oye wee he 14 11 11 2 11 eemricd (na) eee aurea Neel 8 eT zoe 11 15 12 21 Brisrernimead owilar kee ee, ne 16 19 12 9 SS ES ee ae us se cs 25 31 eric ace meen met nee Se AEE 5 ats 50 1 ea ate ee ee 3 am. 42 re 6 PER INVANEE igs rete eer ee a 21 15 Ae 13 ipo Tagg Sg a xe 11 23 12 1 SaEaTany Ne Meemen eye Nae te Lh ee se 15 25 4 at eG 2N 2 US Ca ee Rea ae ae 11 a 25 1 og) ae ie Ae a obs 26 12 1 BUR os aa is 11 15 ae I emt ery st A Bet aes = a 12 14 entrees see - 16 8 —— | 1 Wellow-shafted flicker... — 21 4 — TSS SS a a 14+ 5 a 1 Wellow-billed cuckoo...» as 5 8 6 Pererawinebird> ae 11 4 a Semolinaehiekades oe 11 4 1 Mellon wat Dlere i -—- 16 ---- --- Rufous-sided towhee_.--_ --- —= 11 + MTOR ALC ONY oe 11 --- 3: 2 Tia eye g SU AA ee a eI Bemeeeitie Oriole se ———- 11 (ESRI) 2 Slee 11 ie Red-headed woodpecker_______________-__-__-___-______- 5 4 Great crested flycatcher 5 4 Memeeetiec ae siirike: 2 8 * @ommon nighthawk y serasternm phoebe 2-4 == 3 Brown-headed cowbird 3 Seemdian fycatcher. 0 = 5 Tres oth» Sierayeseel Rae a ee 4 3s -- iellow-breasted chat... = -—-- -- -—-- 3 US ae 3 ate = — aa Grasshopper sparrow _______-----------------------------—- — --- -- —— Seenlentivied (birds seen soe ee ek 17 ae 8 50 26 mntal birds per 100 acres. 199 668 475 658 go1 Metmber of. species. 12 i 328 27 WE AN Bye 430 peach trees. Trees were 10-20 feet tall and equidistantly spaced in rows. ‘The ground cover was bluegrass. A typical orchard censused in 1907 is shown in fig. 20. In the two study periods combined, 172 acres of orchard were censused, table 3, most of them in southern Illinois. Orchards were shown to be excellent bird habitat, supporting high populations and a varied avifauna. In southern [Ili- nois, summer bird populations in orchards . were higher than in any other habitat ex- cept red clover and residential areas, fig. 24. Census data for the years with the largest acreages censused, 1909 and 1958, indicated populations of 3.9 and 4.7 birds per acre in the southern zone and 2.0 birds per acre in the northern zone (391, 475, and 199 birds per 100 acres, table 34). At least 45 species of birds were identi- fied in orchards, table 34, virtually all be- ing potential nesters in this habitat. The mourning dove, field sparrow, robin, and indigo bunting were reported in both northern and southern I[]linois in the sum- mers for which census figures are availa- ble. In addition, in the southern zone, the house sparrow, cardinal, eastern meadow- lark, mockingbird, and yellowthroat were listed in all census years. Table 35—Common birds (species making up approximately 85 per cent of birds counted in strip censuses) in orchards in the southern zone of Illinois, summers, 1907-1909 and 1957— I_ttinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3” Comparisons of bird populations of 1907-1909 with those of 1957-1958 are dificult to make because of the marked year-to-year variations and the small sizes of the samples, but there appears to be no real difference in total density of the or- chard bird populations of the two periods. Population changes in some species oc- curred, however, table 35. An increase in” population of the redwinged blackbird was apparent in this as in other habitats, and an increase in the barn swallow popu- lation in orchards was indicated. An ob- servable decline occurred in orchard popu- lations of a few species, particularly the orchard oriole, tufted titmouse, house wren, yellow-shafted flicker, Carolina chickadee, red-headed woodpecker, crested flycatcher, and eastern kingbird, tables 34 and 35. Forests (Summer) About 40 per cent of the land area of Illinois was originally forested, but three- fourths of this area has been cleared (King & Winters 1952:20-1). We estimated that there were about 3,500,000 acres of forest in Illinois in 1907-1909 and nearly 4,000,000 acres in 1957-1958. Most of the forest lies in southern Illinois. 1958; + indicates approximately 0.5 per cent. 1907-1909 1957-1958 Species Per Cent Species | Per Cent Rausensparro wee ee ne 16 House sparrow. 2 ts eee 16 Hela sDALTO Wesel 10+ Common grackle ta ae 13 NiGurnine dove 20) Sins fee cn 9 Mourning dove. 2s eee 11 Cyretard eriele Ao elk Uo iin TEs 7+ Stanlingsbe 3 te see fee 8 Common grackle ___. PITTA atta © 5+ Redwinged blackbird 8 ELE aE ie pac RAE eta CW nian ete eee os 5 Field sparrow _ Ca Oe 6 OETA EG (6 ROuMta ec ANEE TSA URC RATT 4+ Cardinal __ so) Sle Ta oe ee 5 Bie ay oo ee eee 4 Barn swallow’ .22.2. 6 see 4 rows thrasheér 2220225 oo at 3 Indigo) bunting: 6. eee 3 Eastern meadowlark 3 Brown thrasher - 3 Mocking birds: 225) ere 3 eee 3 Eastern meadowlark epee hie eee 2 Tufted titmouse LEOENAL Leos 2+ American eeldineh pee ENS eit ae 2 Bewickistwren: ise) ates Siena 2-- | Bobwhite _ ara ae S Seed oe 5 2 Cardinal _ 2+ | Dickerssel =: 22) 535: 2 Yellow-shafted flicker 2 House wren es Mie Se SS 2 Imarporpun ting 52 as ee elon Z meliswawiarblen<:- 2" jews). o" scaler ae 1-- ORR Rerii eet 2 Se 2 ee 85 Total per cent... isa eee ee 85 Number Of species: 0255 ee 18 | Number of species.-__.-..-------------------.—- 14 October, 1963 GraperR & GRABER: Birp PoPULATIONS IN ILLINOIS 431 Table 36.—Statistical data on summer bird populations in Illinois forests with understory as determined by strip censuses in the three zones. Data are (1) from all such forests censused and (2) from sample areas (each 1 acre or more) in these forests. | ALL Forests SAMPLE AREAS WITH | : * x MEAee 2 ZONE pica daa Birds Per Acre AND ~ YEAR Number Birds Observed M Standard | Standard) Mean + Acres Par kere Range ean | Deviation | Error 2S.E Northern 257 es 66 22 6 0.6—-5.7 22 1.9 0.8 0.6-3.8 i()S95 7 ee a 73 1.1 It 0.0-2.3 0.8 0.7 0.3 0.2-1.4 Central IS + BES 2 = 2.6 1D (Oe 12 3.5 4 2.1-6.8 B53 et, a 1a MN fee on 3 90 Pps a 0.4—3.2 7) 0.9 0.3 1.1-2.3 1) ie 91 2.6 7 0.8-2.6 1.8 0.6 0.2 1.4—2.2 Southern ILS 037/50 em 20 3.5 11 0.6-7.3 2.9 ily 0.5 1.9-3.9 1 SYR) eaves a aa 40 4.1 8 2.9-7.3 4.0 1S 0.4 3.2—4.8 TOS (fp ee 167 2.6 16 0.9-6.6 2.6 1.6 0.4 1.8—3.4 1958 157 PP 12 0.9-3.4 2.1 0.7 0.2 1.7-2.5 Relatively little woodland was censused quantitatively in 1907-1909 (only 78 of the 809 acres censused in the two surveys, table 3). Because forest is such an im- portant habitat for birds, in the summers of 1957 and 1958 we censused woodlands whenever our route crossed this habitat, even though the strip census is not well adapted to woodland areas. Most of the acreage we covered represented mature deciduous forest with understory; 85 acres of the woodland we censused lacked un- derstory. In southern Illinois, the forest was found to be a very rich habitat both in terms of species and numbers of birds, but, in northern and central Illinois, certain open-field habitats attained notably higher densities, figs. 22-24. As in other habi- tats, there were marked year-to-year dif- ferences in bird population densities in for- est, tables 36 and 37. For woods with un- derstory, the number of birds per acre for all regions and all summers in which cen- suses were made ranged from 1.1 to 4.1; the number of birds per acre in consecu- Table 37.—Statistical data on summer bird populations in Illinois forests without under- story as determined by strip censuses in the three zones. Data are (1) from all such forests censused and (2) from sample areas (each 1 acre or more) in these forests. } ALL ForEsSTS | SAMPLE AREAS WITHOUT = see = a ZONE oe Birds Per Acre AND = = — = YEAR Number eres Birds | Observed Range Mean Per Acre Northern He iisy/emeeee er ie eT Ek Seal 13 8.6 3 | 2.7-17.8 8.8 DIGS ieee nse bey ky en 25 1.4 5 0.0—2.5 G2 Central ROSH ase ee ee ee ee 7 4.8 1 oat 3 HN) Rime ree eS Foi AE os St ee 26 D3 d 1.2-3.4 Zid, Southern NS rst tw nL pt 2 I 5 7 3.0 2, 3.0 [SIGS Sed lek elo 2 Sn Ree ae ee ne 7 3.2 2 2.6 432 ILtinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3% Table 38.—Summer avifauna in Illinois forests (birds per 100 acres) as determined by strip censuses in the three zones (forests with and forests without understory were included in the counts). Figures in parentheses indicate numbers of acres censused; data from the northern and central zones in 1907 and 1909 are too meager to be valid and they have not been included in this table. All stands included in this table were mature, natural deciduous forest typical of Illinois. Dense thickets of young saplings were not classified as forest. Most of the species — of birds listed in this table are known to nest in forest. N pean se viride a SOUTHERN ZONE SPECIES 1957 | 1958 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (79) | (98) | (97) | (117) | (20) | (40) | (174) | (166) Sard tyne]: ee seh oe aa ee 14 6 33 29 10 20 16 28 utted ‘timauseso 2 2 ys ee PR 1 fuss 25 16 35 5 17 21 Ce Po OTT C1) (pe Rea I Soe, Se ly 5 4 7 9 5 25 21 10 SiG payee ese ie AS oe ee ene 5 7 8 17 30 38 3 ) Chickadee (species ?:) 2-5 16 15 13 8 eu mee 12 11 Great-crésted flycatcher. cet 3 8 5 20 28 5 1 Red=eyed Vireo 2-626. ke en 3 2 a 14 11 7 3 5 8 8 7 Eastern wood pewee__.___________________ 9 6 9 10 5 10 8 3 Brawn dina shen ve ee 3 a 2 10 30 15 ake: ae Downy woodpecker...» 5 2 13 11 15 5 3 4 Gomnionigrackles< su 2 ere 8 mans ee 6 40 ais 2 1 BielauspaLro yess ee a ee ee, 1 1 a ee 40 Z 2 Brown-headed cowbird_......_ 28 BE 8 4 veal 5 8 ROD Re sunt Leave bine ia eae heeride dy 9 4 wae 11 5 20 1 Me Rufous-sided towhee_. + 1 4 15 10 9 5 Commoner we eas ee a 8 1 6 9 eee 13 9 i WRIA Chere fe eI ae) Tere 1 1 Meer 1 20 13 3 6 Aeadianiyentohie nc: IP yeh lek os 1 : 5 ae eae 5 17 12 Moaunning doves! sss ee Sete 1 oa 1 12 10 8 3 2 Yellow-shafted flicker... 6 5 eZ 3 5 13 oe eh Red-headed woodpecker... 1 6 3 6 5 13 pe) = American poldineh, Wi. 0s ie Se 8 ii 3 te! 10 as 3 2 PAAMeTICAN TEGStare 2 2c. se eh einen Dentted ay 1 19 5 me z 3 2 Red-bellied woodpecker... at at 4 5 5 5 6 4 Garolindwiren se. sn tee ccreie Ls Saeed nee 2 3 2, 5 8 11 Blue-cray gnatcatcher. 0 4 as 1 3 Eee! 6 12 melllowthroat eek Ae ee at 2 1 18 4 1 Yellow-breasted chat. d 284 1 . 5 15 3 Z Basteronb] uebitdes se oo | hae Foe 1 5 2 : 10. 5 2 Be. Kentucky warbler{- ma a ties Be he 4 8 11 Oven birdie nse ol as ee et eee a ete 13 4 2 2 . 2 pei Carb rrd ea: eset. Bin Bree ee oe te 3 2 2 12 1 ss AOUSE iW REN 2a ee a, Lm aieds 4 1 4 10 mah : ob witttesc = take no eet Dey es i pos x 2 At 10 1 2 SParLoyy, nawk wes ae. Ee ie ze Gh 15 pa 35 Wohsite-eved. vireo. fo oe eet! a 6 aise 2 10 4 Punuier tanacer 200 cee & ‘ 5 ae 5 4 Be wick e wren: ie pi a eae fe Se: 7 : 13 noe ae Ruby-throated hummingbird 1 2 1 2 3 2 ia Pidity woodpecker © ji. ee 1 + ay 2 4 Protnonotary warblenauc.-6 sal) owen te 5 es eis nite 8 1 2 Redetailedihtawk. 2c we eee ay 5 1 1 2 ee as pi 1 SOND Sparlow. 5). wet et Oe rey 3 1 3 ieee aa a 3 pu! Ji) bi (teers See RUG SRE MB Nees ee ey 10 : E ‘ ss ms: Redwinged blackbird... 5 2 oi ed, Se: 238 1 1 Belted kinpfisher®.2 2 tt ates ue ey 5 3 a pete: White-breasted nuthatch 1 1 2 Z : 2 om Worm-eating warbler... oes Fhe oh 6 4 Certlean warbler 3 Sn ey 1 1 os 3 2 Yellow-billed cuckoo 2 3 ae. 1 October, 1963 Grasper & Graser: Birp PopuLATIONS IN ILLINOIS 433 Table 38.—Continued NORTHERN CENTRAL a é Fa WERT ne SOUTHERN ZONE SPECIES | | | 1957 | 1958 | 1957 | 1958 | 1907 | 1909 | 1957 | 1958 (79) | (98) | (97) | (117) | (20) | (40) | (174) | (166) “sdurivall (Oni | 2M Ss Sees on Oe a 5 ot 1 Yellow-throated vireo... ; <2 1 ee eee ed oko 2 Rose-breasted grosbeak. 3 r a 3 ome Bretletitanaren 20. ee 3 ae 1 1 Brestemmi Kamo bind 2. as 3 5 Te Bere MATGuOTIOlG Seo : 5 WY ave 5) Ip f=45 gh (0) a ac 1 3 Be Seine ar leres se aT ee a pa 2 2 LAVAS SDE RCO) (ee 1 3 3 Red-shouldered hawk... : 2 3 Ring-necked pheasant... 3 ues Pileated woodpecker... a ba 2 1 Mellowewarblers= 0 2 1 Mneatiborned owl. = 2 8 2 = sie BOC my an Dlete ses ee ee ae = 1 1 alinmoeontole ss. 8 1 1 = es iSceatiblue heron 1 ae Moammonvemretm rt. oy bt 1 PGrenpmerOnme ena ee fe 1 a Btimkensovilire ss. po ee pee 1 Moopen saw kee ee ee 1 ae Plack-billed:cuekoos.. 1 Binip-poor-walls = 1 = Panes yitteswe see es Ne 1 = Beretmpngebe 8 OF — 1 Black and white warbler As 1 Louisiana waterthrush ses cael 1 an PIGMSCRSD ALLO W228 2 ne 1 ee Meadowlark (species?) 1 a ainesomosbeakers a wy 8 = 1 <5 Dendrocopos (species?) 5 ott 1 lev Kas((SDECIES:?) ee es 1 Caprimulgus (species?) es a 1 Leah lye! "al! Sr cs ep Mindentified! bird -. 9 UICC TG. iile #5 13 16 20 moial birds per 100 acres 222) AIS | 21S? \ 256-550 st 409 sie roerabeaes. Mmmberof species 9 37 30 | 38 38 24 34 52 47 tive census years in one zone (northern Illinois) ranzed from 1.1 to 2.2, table 36. In central [llinois, we found, popula- tion densities for woods with understory were 2.2 birds per acre in 1957 and 2.6 in 1958, table 36. Kendeigh and Ken- deigh et al. (in Audubon Field Notes 1950-1960) presented data on the inte- rior of a woodland in east-central Illinois showing that densities ranged from 151 to 275 territorial males per 100 acres in an 11-year period, 1950-1960. The popula- tion levels for all birds (both sexes) might have been twice as high. These data were from breeding-bird censuses. They sug- gest that our strip census figures are low. Our counts may have included relatively few of the females in the population. Bird populations in forest with under- story in southern I]linois in all census sum- mers ranged from 2.2 to 4.1 birds per acre, table 36. A southern Illinois forest with understory, censused in 1907, is shown in fig. 21. The population figures for both the central and southern zones were con- spicuously higher in 1907-1909 than in 1957-1958. This situation is in marked contrast to the situation in open-field habi- tats, where highest populations were re- corded in the later censuses. The acreage 434 Table 39—Common birds (species making up approximately 85 per cent of birds counted in strip censuses) in woodlands with understory in Illinois, summers, 1957 and 1958. Ittinors NATURAL History SURVEY BULLETIN NORTHERN : Zone CENTRAL ZONE Vol. 28, Art. 3 SOUTHERN ZONE Species | Cent Species eel | Species sa Chickadee (species?) | 25 | Cardinal...) “44. Cardinale 10 Brown-headed cowbird.| 11 | Tufted titmouse........|. 11. | Tufted titmouse —______ 9 Red-eyed vireo 10 | Blue jay_ fat 6 | Indigo bunting — 7 Cardinal ~ 8 | Downy woodpecker. pet 5 | Acadian flycatcher. 7 Ovenbird 7 | Chickadee (species?) 5 | Chickadee (species?) 5 Dendrocopos (species?) 5 | Eastern wood péwee__- 4 | Carolina wrens 4 American goldfinch 5 | Indigo bunting 4 | Kentucky warbler__.___. 4 Eastern wood pewee + | Mourning dove... 4+ |Blue-gray gnatcatcher_ 4 Indigo iene 3. 0) Robins ss es ee 3. | Red-eyed vireo... 3 Robin = oi ae Sun Catbing: tase Sea 3 | White-eyed vireo... 3 Starlinip. <= = 35° pia 2 | American redstart .__. 3 | Rufous-sided towhee — _ 3 Red-tailed hawk 2 | Brown-headed cowbird_ 3. | Brown-headed cowbird ~ 3 Common crow.. 2 | Great crested flycatcher. 3 | Eastern wood pewee..... 2 Blue jay— 2 | Brown thrasher__.... 3 | Wood thrush___.____.____. 2 Ruby- -throated humming- Red-bellied woodpecker 3 | Field sparrow... 2 Lf ot pee SM, Seat 1 | Red-headed woodpecker 2 | Common crow -_.--... 2 Red-headed woodpecker. 1 | Common crow. 2 | Red-bellied woodpecker 2 Housefwren 1 | Red-eyed vireo - = 2 | Summer tanager —_____ 25 Criiire este 1 | Common erackle_ a5 ee ee 2 | Worm-eating warbler 2 Blue-gray gnatcatcher__ 1 | Hairy woodpecker _ 1 | Downy woodpecker 2 Rufous-sided towhee —__ 1 | Mourning dove — i Field sparrow... 1 | Cerulean warbler______ ty Yellow-throated vireo _. ie American goldfinch Lit | Blue jay. 22 eee 1 American redstart 1 Yellow-breasted chat__. 1 Total per cents | 84-9) Netal percents 2 ees 85 | Total per cent 85 Number of species_____| 19 | Number of species 22 | Number of species. 27 Table 40—Common birds (species making up approximately 85 per cent of birds counted) in woodlands in the northern zone of Illinois, summers, 1957 and 1958. W oopLANDS WITH UNDERSTORY WoopLanps WITHOUT UNDERSTORY Per Cent — Species | Per Cent Species Chickadee (species?) | 15 Common grackle —_-_ ae 8 Brown-headed cowbird 11 Yellow-shafted flicker = 6 ed eyed wited 6s Fae 10 Blue jay = eee 5 Cardinal. 8 Eastern bluebird... = 2. ee 5 Mat) 1 Ir ieee ala a 5 Wiican aes: 7 Eastern wood pewee......._-----. 4 Dendrocopos (species?) 5 Red-headed woodpecker. 3 American goldfinch.. 5 Redwinged blackbird 3 Eastern wood pewee 4 American goldfinch 3 Indigo bunting —__. 3 Robifices. oe 2 127) 0) 0 Westies oo Be 3 | Common crow. ee 2 Starling __. 2 Starling eee 2 Red-tailed hawk ee AEE 2 Conimon crows So ee eee 2 Blue jay a) 2 Ruby- -throated hummingbird _ EAS: 1 | Red-headed woodpecker 1 / MOUSE OV Tet Lo oe ae 1 Craton Fi 52 ok a 1 Blue-gray gnatcatcher____._.__ 1 UROTALID ET DERE e eek a Ae es oN &4 Total per cent. 2a eee eee 82 Number of species. ecw a 19 | Number of species gy.) 11 October, 1963 GraBper & GRABER: of forest censused in 1907-1909 was so small that the figures derived may not be representative. At least 80 species representing 27 fami- lies of birds were identified in forest (both with and without understory), table 38. The cardinal, indigo bunting, blue jay, red-eyed vireo, wood pewee, and downy woodpecker were recorded in all summers Birp PopuLATIONS IN ILLINOIS 43 and zones in which censuses were made. Other species for which the frequency of occurrence was very high were tufted tit- mouse, crow, crested flycatcher, towhee, mourning dove, and wood thrush. Indica- tions of increases in forest populations be- tween 1909 and 1957 were shown by the chickadees, blue-gray gnatcatcher, Ken- tucky warbler, and white-eved vireo, table Fig. 21.—Forest with understory in southern Illinois censused in the summer of 1907. Such species as the summer tanager and wood thrush were recorded here. The photograph was aken east of Shetlerville, Hardin County, June 29, 1907, by Alfred O. Gross. 436 I_Linois NATURAL History SuRVEY BULLETIN 38. Species that showed some consistent marked population reduction between 1909 and 1957 were blue jay, crested fly- catcher, wood thrush, brown thrasher, red- headed woodpecker, and yellow-shafted flicker. Lists of common forest species (species comprising 85 per cent of the populations in forests with understory) in the three zones in the summers of 1957 and 1958 are presented in table 39. The forest avi- fauna was progressively more varied from northern to southern latitudes. The num- bers of common species in the southern zone were about the same in 1907-1909 as in 1957-1958 in spite of the much larger area covered in the later censuses. Though there were no consistent differ- ences in density of bird populations be- tween woods with understory and those lacking understory, tables 36 and 37, there Vol. 28, Art. 3 were qualitative differences, table 40. The avifauna of the forest without understory was less varied, and the species composi- tion was different in that such shrub-nest- ing and ground-nesting species as the car- dinal and ovenbird were scarce or lacking in forest without understory. Urban Residential Areas (Summer) The spread of urban residential areas began long before the first strip censuses reported here, but the acreage of land oc- cupied by human residences and lawns in-’ creased greatly after 1909. We have esti- mated that acreage of this habitat climbed from about 350,000 acres in 1907 to 820,- 000 in 1957. Only a small acreage of urban residen- tial areas was censused in the summers of 1907-1909. In 1958, we made summer censuses in the residential areas of several Table 41.—Summer avifauna in Illinois urban residential areas (birds per 100 acres) as determined by strip censuses in the three zones in 1958. Figures in parentheses indicate num- bers of acres censused. Most of the species listed are known to nest in this habitat. NorTHERN ZONE | CENTRAL ZONE | SOUTHERN ZONE epee (160) (75) (98) Plouse sparrow 22560" a say vw 435 378 271 Starline entered eke 121 119 180 Robin seo ea ea SN ee 132 109 102 Commoniprackle 02) eee ee 96 27 22 Dire) Ca ig Se a eat On ne Re eto AT 69 40 38 Mourraitip dove re! 720) 0 eh Utne ae 31 38 17 Purpleanartine ss Oe oes eee 25 11 42 Chimney{switt. es Wait rok ne, 14 27 24 bE aa gees peeve SOS PRP 16 16 21 REGUS CLIT eNT acre Re ore ee ey 17 13 16 Gatbinds, <0 ctks es OE Lie aye meek 1 4 22 Car ditial see soe en es sued sh ema See 6 4 9 Yellow-shafted flicker. = © 6 8 4 OTOWO (rage rns oo aes Bic sy PaaS ie, 1 4 3 Great crested flycatcher... di ee 5 A eten titeiouse. 8 we ee a : 5 hippie eparco w afte se eee 3 tims 3 Eastern wood pewee _......... 1 1 1 Red-headed cca ST Rae EAE TT" as aha 2 Wood thrush _. DMR iia aa ET re eal Pe 2 Ty AX EG 88 i 5 1 1 Downy, woodpecker! a ee 1 2 oes RPLOC RUNS Dare se re ei eee ee pe ms 1 PALO acy ren. = 28 2k Oe Se een zh is i Red eve vireo: =k es A een, 1 = ue Brown-headed cowbird..... pee 1 oe Rufous-sided towhee_...._ a Ec} 1 BOMCISD ATT OV ss spate. Fee koa en ae 1 pice pmentined Wired (lo a eee 7 3 24 hota birds: per 100 acres == ee 2 984 804 814 Number of species a2 sl Fe aw ae, 19 17 23 October, 1963 GraBeR & GRABER: Biro PopuLaTIons IN ILLINOIS 437 Table 42.—Commion birds (species making up approximately 85 per cent of birds counted in strip censuses) in urban residential areas in the three zones of Illinois, summer, 1958. NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE : Per . Per - | Pex Species Gent Species Glael Species bent House sparrow ...........-.. 44 | House sparrow. | 47 | House sparrow... maliog. DS RCTS & SUE ii V0 ie ae a ae 5-> Stateline us! eos Vereen |: 023 ae io 2) Robin er en aS 2370 ROBIE ee oe ts rR eee Lends Common grackle LO Rockudovere! 1:2 tee Se) Pcp le maar tine se eee 5 Rockidoves 8. Si 7 >| Mournme doves so 5° Bye ip liworg tel Glan eee te Le 5 Chimney swift. miles 3 Catbird 2) tae 3 mansal per cent 800s Lota) per Cont. Fo 8) || Potal- per cent. 3 2 | 86 Number of Number of | Number of common species _____ 5 common species ______ 5 | common species 7 Total number ‘Total number ‘Total number | nempecress 246M) 2) 19 of species 17 | of species 2 U8: 23 small cities in the three zones of the state; 333 acres of this habitat (yards adjacent to human dwellings) were censused in this year, table 3. As bird habitats, urban resi- dential areas closely resemble open forest ; they include some avifaunal elements of forest and shrub-grown areas. The urban habitats censused in sum- mer, rich in numbers of birds, had higher population densities than any other habitat except edge-shrub areas, figs. 22-24. Pop- ulation densities in the urban habitats varied from 8.0 birds per acre in the cen- tral zone and 8.1 in the southern to 9.8 per acre in the northern zone (804, 814, and 984 birds per 100 acres, table 41). A distinctive characteristic of the sum- mer avifauna in this habitat was its con- stancy from zone to zone. The avifauna was not rich in numbers of species; only 28 were identified, table 41. Yet 15 spe- cies were reported in all three zones. In all other habitats, greater regional differ- ences in the avifauna were apparent. Though there were relatively few quali- tative differences in the avifauna from zone to zone, population densities of sev- eral species showed interesting variation. A density cline was evident in the popu- lation of house sparrows, high in the north, much lower in the south. Other species with relatively high populations in the north were the robin, grackle, and rock dove. The starling and the catbird had their highest population densities in the southern zone. The constancy of the avifauna from zone to zone was emphasized especially in the lists of common summer species, table 42. Five species in the northern and cen- tral zones and seven in the southern zone comprised 85 or 86 per cent of the total summer population in this habitat. Four common species, the house sparrow, star- ling, robin, and rock dove, were recorded in all zones in all census years. Three of these are introduced species that find op- timum habitat in close proximity to man. Comparison of Data for Summer Habitats It can be seen from the foregoing that each habitat tends to have certain avi- faunal associations. For some summer habitats, the avifauna is quite distinctive, and each habitat can be defined to a cer- tain extent in terms of the qualitative and quantitative characteristics of its avifauna. For an understanding of the value of a given habitat, it is worthwhile to make direct comparisons of the avifaunal char- acteristics of this habitat with the charac- teristics of others. Comparative data on bird populations in different habitats in the three zones of the state are presented in figs. 22-24. For convenience in the following discussion, however, we have combined data for the three zones in order to have a single number represent each habitat. Unless otherwise stated, figures on population densities in different habi- tats represent all summer censuses (years 438 BIRDS PER ACRE Oo 10 20 30 40 50 60 70 80 90 100 eee ee EE EEE RESIDENTIAL 4& MARSH a « a SHRUB a _swxep Hay SWEET CLOVER 4 a 4, RED CLOVER UNGRAZED GRASS A EFALLOWw A 1957 PASTURE A 1958 4 ALFALFA A ORCHARD NORTHERN ZONE SUMMER A, oats 4 FOREST 4 CORN p& SOYBEANS i@) 10 20 30 40 50 60 7.0 80 9.0 100 Ed ERE eS a ea ee a ee 2 ee ae BIRDS PER ACRE Fig. 22.—Densities of summer bird popula- tions in a number of habitats in the northern zone of Illinois as determined by strip censuses in 1957 and 1958. The point of each triangle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. and zones) combined and include all birds seen and all acreages censused. Number of Birds.—Of the 17 major summer habitats censused in the various years and zones, the row crops of corn and soybeans consistently supported the lowest bird populations; they had an aver- age density of about 0.6 bird per acre. Plowed ground, oats, and wheat were also poor habitats for birds; their average pop- ulations were 0.8, 0.8, and 0.9 bird per acre, respectively. Bird populations in oat fields showed marked increase between the 1909 and the 1957 censuses; populations were consistently low (0.6 bird per acre) in the early censuses, but relatively high in later years (1.7 birds per acre), primarily because of increases in the Icteridae. Pop- ulations in wheat fields showed no such change. Wheat, which is harvested earlier than oats, is a less attractive habitat. Inttinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 37 Summer bird populations in grasslands and hay crops were variable, but usually conspicuously higher than in the bare- field, row-crop, and small-grain habitats. For these, the average bird population levels (birds per acre) for all censuses were as follows: fallow fields, 1.6; pas- ture, 1.7; ungrazed grassland, 2.2; mixed hay, 2.2; alfalfa, 2.5; red clover, 2.8; and sweet clover, 4.1. Forests (all types) in summer sup- ported populations of 2.4 birds per acre, about comparable to grasslands and hay habitats. The remaining habitats, shrub- grown areas (3.5 birds per acre), orchard (4.0), marsh (7.9), urban residential (8.9), and edge shrub (22.3), supported — denser populations of birds. In several habitats (plowed fields and — row crops), the population of breeding species constituted only a relatively small part of the total population of these habi- — tats in summer. Populations of breeding species were ().2 bird per acre in corn and — BIRDS PER ACRE Oo LO 20 30 40 50 60 70 80 90 100 a ea eens a a RESIDENTIAL 4& SWEET 4 CLOVER wien _ say 5—4 RED CLOVER SHRUB £ 4_, ALFALFA A FALLOW —, PASTURE A 1957 v= FOREST A 1958 4 oats 4, A WHEAT 4, CORN 0 10.20 30 40 50 60 70 80 90 BIRDS PER ACRE SOYBEANS CENTRAL ZONE SUMMER 10.0 Fig. 23.—Densities of summer bird popula- tions in a number of habitats in the central zone of Illinois as determined by strip cen- suses in 1957 and 1958. The point of each tri- angle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. ; October, 1963 Graper & GRABER: BIRDS PER AGRE PaO a0 30 40) 50°60 70 80 SO 100 Ee aS ee RESIDENTIAL A A ORCHARD A——* RED clover A, sHrus A FOREST aA——* A ALFALFA x4« AA a FALLOW MIXED HAY A 1957 A \958 PASTURE UNGRAZED GRASS AA OwHEaT A CORN SOUTHERN ZONE SUMMER 4 PLOWED x’ soyYBeANs O | 2.0) 730) 74.0" 5:0) 60) 70) 80: 910: 1010 BIRDS PER ACRE Fig. 24.—Densities of summer bird popula- tions in a number of habitats in the southern zone of Illinois as determined by strip censuses in 1957 and 1958. The point of each triangle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. 0.4 bird per acre in plowed fields and soy- beans. In wheat, the populations of breeding species were 0.3 bird per acre. In oats, the level of the breeding population changed markedly from 1907-1909 (0.2 bird per acre) to 1957-1958 (1.1 birds per acre), and the average figure for the two census periods (0.4 bird per acre) has little mean- ing. The grassland and related habitats had varied populations of breeding birds; 0.8 bird per acre in fallow fields and pastures and 1.5 birds per acre in ungrazed grass. The population levels in pasture, at least, showed some increase from 1907 to 1909 (from 0.5 to 0.7 bird per acre) to 1957 to 1959 (from 0.9 to 1.4 birds per acre). Ungrazed grasslands had notably higher summer populations than other grass hab- itats and higher proportions of breeding birds relative to the total populations. Birp POPULATIONS IN ILLINOIS 439 Breeding-bird populations in hay crops were less varied qualitatively but higher quantitatively than those in grassland. The numbers of birds per acre were 1.5 in mixed hay, 1.7 in alfalfa, 1.9 in red clover, and 2.8 in sweet clover (small sample). Breeding-bird populations in hayfields increased markedly during the half century following 1909. Virtually all of the species recorded in summer for forests and urban residential areas were potential breeders or nesters in these habitats. Populations of breeding species were, for forests, 2.4 birds per acre; orchards, 3.3; shrub-grown areas, 3.5; marshes, 5.5; and urban residential areas, 8.9. Number of Species.—The censused habitats that supported the greatest num- bers of birds in summer did not necessarily support the most varied avifaunas. How- ever, the row-crop and bare-field habitats (corn, soybeans, and plowed ground) that had low populations in terms of birds per acre were also low in numbers of species. In these habitats, only the horned lark oc- curred regularly as a nesting species, ta- bles 5 and 7. In small-grain fields, the total nesting avifauna, which included at least 10 spe- cies, was much more varied than that in row crops, tables 10 and 12. Even more varied was the avifauna of grasslands and fallow fields, which sup- ported at least 20 species of breeding birds, tables 14, 15, and 17. The avifauna in hay crops was less varied than that in grasslands. The 14 species of birds breed- ing in hayfields were grassland species that tolerated or even preferred the tall, dense hay cover, tables 19, 2+, 26, and 28. The marshland avifauna in northern Illinois was rich in number of species, and at least 18 of the +1 or more species in the marsh habitats in summer were nesters, table 30; this habitat was similar to grass- lands and fallow fields in number of breeding species, but the marshland avi- fauna was much more specialized. ‘The woody habitats (shrub areas, or- chard, and forest) were the richest of the summer habitats in numbers of species, tables 31, 34, and 38. About 40 of the 7+ or more species of birds found in shrub- grown land probably nested in this habi- tat; in orchards, 37 of the +5 or more spe- 440 [LLiNo1is NaruRAL History SuRVEY BULLETIN cies recorded were probably nesters; and virtually all of the 80 or more species found in forest probably nested there. Residential areas, though a woody habi- tat, had a much more restricted summer avifauna, with 28 species, table 41, prob- ably all of them nesting in this habitat. In two habitats that were roughly simi- lar, the population density tended to be higher in the habitat in which the avi- fauna-habitat relationship was more spe- cialized and the avifauna was less varied. For example, residential areas, which had a more specialized avifauna-habitat rela- tionship and a less varied avifauna than forests, had consistently higher popula- tion densities. Statewide Summer Populations A factor that must be considered in evaluating a particular habitat for birds is its total acreage. For instance, though ungrazed grasslands support a relatively high population of birds per unit of area, this high population density has little ef- fect on the state population because of the very limited acreage of the habitat. Extrapolating from the crop acreages presented by the Illinois Co-operative Crop Reporting Service (Ewing 1959), the U. S. Bureau of the Census (1913, 1961), and our census data, we can roughly estimate the total number of birds in a given habitat and also the total num- ber of birds in the state for the summers of 1909, 1957, and 1958 (no data for northern zone in 1907). Illinois has a total land area of about 35,800,000 acres. Ironically, the largest single habitat type in the state (row crops, principally corn and soybeans) is also one of the poorest of the bird habitats. If the censuses show the true distribution of birds in the various habitats of the state at given times, then in the summer of 1909 there were about 6,376,000 birds in the row crops (10,483,000 acres): corn (10,- 173,000 acres) and garden vegetables (310,000). By 1957, the land in corn (all types) had been reduced to about 8,280,- 000 acres, but another row crop, soybeans, had come into prominence and amounted to 4,979,000 acres, while garden vegetables accounted for only 70,300 acres. The total area of row-crop habitat was thus in- creased by nearly 3,000,000 acres over the Vol. 28, Art. 3 1909 acreage. In 1957, the total popula- tion of birds in this habitat was estimated to be 8,170,000, an increase of about 1,- 790,000 over the 1909 population. The importance of the row-crop and plowed-field habitats as feeding grounds for birds is difficult to evaluate. The ulti- mate appraisal should be in terms of spe- cies survival, which is closely associated with nesting opportunity; in this frame of reference, the row crops have relatively little importance to the total avifauna. The expansion of row crops at the expense of other habitats represents a loss in both variety and numbers of birds. Small grain crops in Illinois have de- creased in acreage since 1909, when there were about 4,235,000 acres of oats (plus rye) and the summer population in this habitat was estimated to be about 2,955,- 000 birds. In 1957, there were 2,990,000 acres of oats (plus rye) in Illinois; de- spite the decrease in acreage, the bird pop- ulation in the habitat was estimated to be even higher than in 1909 (5,552,000) be- cause of an increase in population density in the habitat, particularly among the Icteridae in the northern half of the state. The acreage of wheat (plus barley) de- creased from 2,250,000 in 1909 to 1,960,- 000 in 1957; the bird population in this habitat also decreased (1909: 1,494,000; 1957: 1,121,000). By our estimate, the area of ungrazed grassland in Illinois decreased from about 331,000 acres in 1909 to 218,000 in 1957, and the state bird populations in this habi- tat from 612,000 birds in 1909 to 464,000 in 1957. We estimated that fallow fields in the state occupied 1,496,000 acres in 1909 and 1,034,000 in 1957; our estimates of the populations in this habitat were 2,244,000 birds in 1909 and 1,663,000 in 1957. In 1909, there were in Illinois about 6,085,000 acres of nonwoodland sod pas- ture that contained a summer population estimated at 11,650,000 birds. In 1957, though over 2,000,000 acres of hay and other crops were used for pasture, sod pastureland amounted to only 1,965,000 acres; the bird population in this habitat — was estimated to be 4,139,000, 7,500,000 below the 1909 population. Not all of the | reduction represented breeding birds; if — we consider breeding species only, the esti- October, 1963 GraBeR & GRABER: mated number of birds in Illinois pastures decreased from 4,800,000 in 1909 to 2Z,- 160,000 in 1957. Coincidental with the loss in acreage of grassland, there was an increased use of cultivated hay plants for pasture in I[I]li- nois, and, in recent years, increased acre- age of soil improvement (soil bank) hay. Thus, while the acreage of hay plants for harvest declined from 3,349,000 acres in 1909 to 2,459,000 acres in 1957, the total acreage of hay plants for all purposes was 5,254,000 acres in 1957, an increase of 1,905,000 acres over the 1909 acreage. In the same period, there was some change in the types of hay produced. Alfalfa had a negligible acreage (18,000 acres) in 1909, but it had become a leading hay crop (1,424,000 acres) by 1957. Timothy, on the other hand, was planted on 1,870,000 acres in 1909, while in 1957 there was very little acreage of pure timothy. In 1909, timothy and mixed hay had about the same qualitative-quantitative avifaunal characteristics, and for final tabulation we lumped the census data for these crops. In all summer hay crops combined, the total summer population was estimated to be 6,834,000 birds in 1909 and 12,930,000 in 1957. For the most part, the increase represented increased acreage, for popula- tion densities in this habitat were similar over most of the state in 1909 and 1957. To some extent, the increase in hayfield acreage replaced the lost acreage in pas- tureland, but the gain in the hayfield bird population compensated for the loss in the pastureland population only in numbers of birds, not in variety of birds. The amount of prairie (nonwood, non- shrub) marshland in Illinois decreased from about 558,000 acres in 1909 to about 60,000 acres in 1957. The estimated total bird population for this rich habitat was 4,140,000 in 1909 and 293,000 in 1957. These figures represent an estimated loss of 3,847,000 birds in the population and, even more important, a loss in faunal va- riety. The marsh avifauna is highly varied and highly specialized, and most of the marsh species cannot survive in another habitat. Based on our census data, the acreage of shrub-grown areas in 1909 (469,000 acres) was close to that in 1957 (507,000 acres). Despite the limited acreage, esti- Birp PoPpuULATIONS IN ILLINOIS 44] mated summer bird populations were high in shrub-grown habitat: 1,993,000 birds in 1909 and 1,892,000 in 1957. In 1909, there were about 301,000 acres of Illinois orchards with an estimated sum- mer population of 1,422,000 birds. By 1957, when orchards had been reduced to about 31,000 acres, the estimated summer population (108,000 birds) in this habitat was negligible by comparison with the 1909 level. Though most species of or- chard birds can survive in other habitats (shrub-grown areas and forest or wood- lands), the loss is still regrettable. Prob- ably much of this high-density habitat, which supported a varied avifauna, was replaced by poor-habitat crops, such as soybeans. Forest or woodland acreage was prob- ably greater in 1957 than in 1909, when there were, by our estimates, about 3,459,- 000 acres with a statewide summer popu- lation of 14,149,000 birds. In 1957, forests covered 3,996,000 acres, but the statewide population of birds (9,886,000 ) was estimated to be less (by 4,261,000) than in 1909, because population densities in forests tended to be lower in the later years. Acreages for urban residential areas in Illinois are not available for 1909, but on the basis of the urban (human) popula- tion and acreage data for urban areas in later years, we estimate that there were about 350,000 acres of urban areas in IIli- nois in 1909. If the 1909 and 1957 bird population densities in this habitat were comparable to the 1958 level, when cen- suses were made, then the estimated sum- mer population in 1909 was about 3,269,- 000 birds. By 1960, the acreage of urban areas had increased to about 820,000 acres and the bird population to about 7,657,- 000. Commercial sections of urban areas have much smaller bird populations than residential sections. Virtually no native species are found in commercial areas; the avifauna of these areas consists almost en- tirely of the three introduced species (house sparrow, starling, and rock dove). Urban residential areas represent a modi- fied forest habitat that can be an important reservoir for several species of native birds. For all of the habitats mentioned, our estimates of the total statewide popula- 442 tions of adult birds in summer were 57,- 138,000 in 1909 and 53,875,000 in 1957. These data accounted for 33,368,000 acres in 1909 and 32,290,000 in 1957, leaving some of the acreage for the state unac- counted for: about 2,499,000 acres in 1909 and 3,505,000 in 1957. In 1957, about 1,289,000 acres of land (excluding urban areas) were covered by the con- crete, asphalt, or gravel of the state or federal highways and 14,000 additional acres were covered by railroad tracks and ties. Some road surfaces (especially gravel) may be of some value to birds, but, if we appraise in terms of species survival, road surfaces must be consid- ered a void in the statewide acreage of bird habitats. Even after the acreage of these areas was included, there were still about 2,202,000 acres unaccounted for in 1957. Some of this acreage undoubtedly represented good bird habitats, such as cemeteries, grassy roadsides, and sod air- fields, while part of it must have repre- sented poor habitats, such as extraurban factories, other rural buildings, and paved airport runways. Included among the high-density habitats, as yet unaccounted for, were edge shrubs (estimated acreage in 1957: 86,000; estimated bird popula- tion in 1957: 1,918,000) and hedgerows (estimated acreage in 1957: 13,000; esti- mated bird population in 1957: 172,000) ; we lack comparative data on these habitats for 1909. If our estimates are reasonably close to the actual numbers, there was little change in the total number of summer bird residents in the state between 1909 and 1957. If the acreage unaccounted for in 1909 and 1957 had harbored bird pop- ulations comparable to those in the acre- age accounted for, then Illinois would have had state bird populations of about 61,333,000 birds (mean density for state, 1.71 birds per acre) in 1909 and 59,778,- 000 birds (mean density for state, 1.67 birds per acre) in 1957. One possible ex- planation of the closeness of the 1909 and the 1957 populations is that the state land area has a saturation population level of about 60,000,000 birds in summer and that this saturation level had been reached at least as early as 1909. There is a limit to the mass of protoplasm that can be supported on a given land area. This mass Ixtinors NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 of protoplasm could be expressed in terms of numbers of birds (and other animals) per unit area. It seems unlikely that the number of birds on a land area the size of Illinois would remain constant from year to year through the decades, even if a saturation level had been reached. Too many interdependent factors are involved including the varied nature of the avi- fauna itself. To obtain data on year-to-year varia- tions in the statewide bird population, we estimated the 1958 population, as well as the 1909 and 1957 populations; no data are available for the northern zone in 1907, and we did not estimate the state population for that year. In the summer of 1958, we estimated, there were 60,244,- 000 birds on 32,806,000 acres of Illinois land (1.84 birds per acre), or, for the total acreage in the state, about 65,586,000 birds, about 5,600,000 more than in 1957. The 1957 and 1958 summer popula- tions showed that the number of birds in the state may vary appreciably from one year to another even though the acreages of each habitat remain about the same. Appreciable variations in bird populations are to be expected. The population in one year depends on productivity in the pre- vious year and on survival of birds in mi- gration and on the wintering grounds. Because weather is variable, productivity (therefore population) may vary greatly from year to year, as well as from habitat to habitat and from zone to zone. For 1957 and 1958, our estimates of bird populations in Illinois cornfields were, re- spectively, 5,705,000 and 5,397,000 birds. In the same period, the number of birds in oat fields changed drastically (1957: 5,552,000; 1958: 3,276,000). While the bird population in oat fields decreased, the population in wheat fields increased from 1957 to 1958 (from 1,121,000 to 2,459,000). Both of these changes may have represented the same phenomenon, that is, a habitat shift by birds from one type of grain field to another. Mean population densities varied some- what from zone to zone. The northern zone consistently had the highest average density in summer. Mean densities in the summer (June) of 1909 were 2.0 birds per acre for the northern zone (2.5 in 1957, 2.4 in 1958); 1.4 for the central October, 1963 Graper & GRABER: zone (1.4 in 1957, 1.7 in 1958) ; and 1./ for the southern zone (1.4 in 1957, 1.7 in 1958). To some extent this variation re- flects the lack of uniformity in distribu- tion of such high-density habitats as urban residential areas, marsh, and forest. The relatively low mean density for the south- ern zone 1s surprising in view of the large acreage of forest in this zone. The gross figures for the statewide summer population of birds include many species of birds, all of which have fluctuat- ing populations. Population increases in one species might cancel decreases in an- other species. It is pointless to speculate further on the meaning of the gross changes until we have considered the in- dividual species in more detail. One generalization can be made here: that among the habitats considered—some primarily natural (prairie, forest, marsh) and some cultivated (corn and soybeans) — the 1909 summer bird populations tended to be higher in the natural habi- tats and the 1957 populations higher in the cultivated habitats. BIRD POPULATIONS IN WINTER HABITATS Bird populations in winter are much more variable than in summer, and com- parison of results of the two sets of cen- suses as an index to long-term changes in the avifauna is somewhat tenuous. Birp PorpULATIONS IN ILLINOIS 443 During the winter season (December | —February 15), 10,180 acres of Illinois land were censused, 5,299 acres in 1906— 07 and 4,881 in 1956-57 and 1957-58. The acreages of each habitat covered in different regions and different winters are shown in table 43. The habitats in order of descending acreage were corn, pasture, small grain stubble, wheat, hayfield, forest, plowed ground, soybean stubble, fallow land, shrub-grown area, orchard, and marsh. The acreages of orchard and marsh were so small that we did not cal- culate the bird populations in them. ‘The bird populations for the other types of habitat are discussed below. A comparison of bird population densities in various habitats is shown in figs. 25-27. Cornfields (Winter) The methods of corn harvesting have changed considerably since the first winter survey by Gross and Ray. Hand-picked fields, which comprised most of the corn- field acreage in the winter of 1906-07, were characterized by the tall cover of the standing stalks and by little grain left in the fields. Fields in which the stalks were cut offered little cover (except where there were shocks) and in this respect bore some resemblance to modern harvested fields. However, none of the early cornfield types was strictly comparable as a winter habi- tat to the cornfields of today. Mechanical Table 43.—Acreages of habitats covered in winter strip censuses in the three zones of Illinois, 1906-07, 1956-57, and 1957-58. | | | NorTHERN CENTRAL | SOUTHERN | | ZONE ZONE ZONE | — _ —— | ‘TYPE OF HABITAT | Torat | 1956-57 1956-57) 1956— 57 | (1906-07 1906-07 1906-07 1957-58 1957-58 | 1957-58 | PA COTM = os t 734 SOOM eS TGe | a OR mee 2 Sila ln ee tar 2,899 i etn, Ye 440 109 S71 |, 156 181) #93 1,350 Smallueram stubble 22° 223 192 280 | 268 | 162 124 1,249 MN dbreicl (eer cepeene ake Te ot es 57 21 2) | PLESTf | 289 293 1,146 cyte ds -2 Se a eee 72 182 164 | 180 90 | 85 873 LP (OTe B wate are: Sa OE Is A 65 45 50 | 52 241 ZA 764 Plowed ground __ sole all eee | 269 68 125% ere s86. | a8 93 659 Soybean stubble wae Gene as. 28 | == 322 G2 126 497 milowyetieldic2 2 foes SA 59 45 | 34 79 114 | 103 434 BineuDeanedeere scene eee. 18 eal ae 74 $3") ELON 239 “COETCEL EET [ee a ie eee 3 3 19 1 18 | if 51 1 LIEU) 0 aA a eh Sats Sra Shae yee _ Th a | + an 8 19 LF AGL Ae CT ME eee neon | 2041 | 1042 | 1,808 |' 2,318 | 1,450 |" 1,521 10,180 | * Some or all of this acreage may have been field bean or navy bean stubble. oe BIROS PER ACRE 0: AD, 2603S 15.0 160 170 SHRUB A A FOREST A FALLOW 4& CORN STUBBLE A SMALL GRAIN STUBBLE A HAYFIELD A PASTURE SES ae 4 PLOWED NORTHERN ZONE A WHEAT WINTER A SOYBEAN STUBBLE 10) LO; +20: 30 150 16.0 170 BIRDS PER ACRE Fig. 25.—Densities of winter bird popula- tions in a number of habitats in the northern zone of Illinois as determined by strip cen- suses in 1956-57. The point of each triangle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. picking of the grain leaves broken-over stalks and scattered grain throughout the fields. Modern cornfields in winter offer relatively little concealing or protective cover, but a considerable amount of food for some species of birds. Of 2,896 acres of cornfields censused for birds in winter (all years), 1,184 acres represented fields that had been hand picked (1906-07), 254 acres were of fields from which the stalks had been cut and removed (1906-07), 93 acres had had the corn cut and shocked (1906-07), and 1,365 acres were of mechanically picked cornfields (1956-57 and 1957-58), tables 44 and 45. In the various types of cornfields, in all census years, winter bird populations tended to be most dense and most varied in the southern zone of the state, least dense and least varied in the northern zone, tables 44 and 45. Two types of cornfield habitats, hand-picked (standing cornstalk) fields in 1906-07 and me- chanically picked fields in 1956-57 and 1957-58, were especially important be- cause each type occupied most of the corn acreage in its period. I_Linors NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 BIRDS PER ACRE Oo 10 20 30 40 8.0 90 10.0 Ot, a4 SHRUB FOREST sh CORN STUBBLE HAYFIELD A 1956-57 A 1957-58 ag a a, PLOWED 4 SMALL GRAIN STUBBLE a SOYBEAN STUBBLE SP lain CENTRAL ZONE A PASTURE WINTER 4 WHEAT 0 10 20 30 40 80 90 100 BIRDS PER ACRE Fig. 26.—Densities of winter bird popula- tions in a number of habitats in the central zone of Illinois as determined by strip censuses in 1956-57 and 1957-58. The point of each triangle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. BIRDS PER ACRE 10) lO 20 30 40 140 15.0 160 170 18.0 ——— SHRUB 4—__, 4, FALLOW a4 FOREST SOYBEAN STUBBLE a___, PASTURE 4___, SMALL GRAIN STUBBLE 4, CORN STUBBLE a HAYFIELD A PLOWED my adios fs A 1958-59 01.10: 2.0" 3.0) “4:0 14.0 15.0 160 170 18.0 BIRDS PER ACRE SOUTHERN ZONE WINTER A 1956-57 Fig. 27.—Densities of winter bird popula- tions in a number of habitats in the southern zone of Illinois as determined by strip censuses in 1956-57 and 1957-58. The point of each triangle indicates the mean number of birds per acre for all fields of the habitat censused in the year and zone specified. The term shrub in figs. 25-27 includes both shrub-grown areas and edge shrub. October, 1963 Graper & GRABER: Quantitatively, bird populations in the two types were similar. Bird populations in hand-picked cornfields in the winter of 1906-07 (most of the censuses were in January) were 0.2 bird per acre (22 birds per 100 acres) in the northern zone, 1.4 birds per acre (138 birds per 100 acres) in the central zone, and 2.0 birds per acre (203 birds per 100 acres) in the southern zone, table 44. Bird populations in me- chanically picked cornfields in the winter of 1956-57 (most of the censuses were in January) were 0.5 bird per acre (50 birds per 100 acres) in the northern zone, 2.1 birds per acre (207 birds per 100 Birp PoPpuULATIONS IN ILLINOIS 445 acres) in the central zone, and 1.9 birds per acre (188 birds per 100 acres) in the southern zone, table 45. Qualitatively, there were some impor- tant differences between the two periods with respect to the winter bird popu- lations of cornfields. The winter avifauna of hand-picked fields (1906-07) was com- posed more of species that we usually think of as shrub or forest-edge inhabitants, while the winter avifauna of mechanically picked fields contained more prairie or open-field species, such as the horned lark and Lapland longspur. The taller cover of hand-picked fields (1906-07) was of Table 44.—Winter avifauna in Illinois cornfields of different types (birds per 100 acres) as deter mined by strip censuses in the three zones in 1906-07. In the first type, the ears have been picke and the stalks left standing; in the second, the stalks have been cut and shocked; in the third, the stalks have been cut and removed, leaving only short stubble. Figures in parentheses indicate num bers of acres censused; + indicates less than 1 bird per 100 acres. NORTHERN ZONE | CENTRAL ZONE SOUTHERN ZONE Stalks Stalks | Stalks SPECIES | Ears page Cut and| Ears eee Cut and| Ears lan aee Cut anc Picked ee an Re- |Picked|<7* 2” Re- -|\Pickad|~U° 299) “Re- ocked Shocked , |Shocked (602) (42) moved | (360) (49) moved | (222) (2) moved (90) (107) (57) Wonimon crows. 3 125 22 4 | 10 Slate-colored yunco_— zx ci 9 ol! 51 47 aimee Sparrow. 2 eed 1 5 1 11 2 40 Meadowlark (species?) se = 59 5 ‘Cans tyre) LS Ee ee ee 213 38 1 3 7 Mourning doves = =i 2 = 1 +4 ele eX 36 si Chickadee (species?) ______.-- aE + 4 2 3 14 Eiguse sparrows 2 2) 7 1 16 Ee 1 2 Babyy initeiavn ste eS + =e fh 16 American goldfinch _________ 9 + 1 =. Yellow-shafted flicker. a 8 2 NeneiSpartow = = 22 8 + be ae 3 5 Riorned ‘lark. = =~. ie, Se 5 + + 2 1 wee Sparcow, hawk 2) ows a 4 1 o 2 Downy woodpecker__________ + 1 5 Hastern bluebird 2. 3 3 Oe AarOlmMarwrel 224 ant 5 White-throated sparrow. fie oa + 2 1VLE 2 CS a + 2 1 set Red-bellied woodpecker ais -+ 3 Whotted titmouse—_...- = aes 2 metkey vulture 1 LP CUSN a ee ee ae ees en 1 iO Mas VECO ee Be: 1 Rough-legged hawk. a ais Red-headed woodpecker... : + Mtockinepind 22 fe ae de Loggerhead shrike.- + aes White-breasted nuthatch mee yt | Hawk (species?) | sie hss + 2 E! + eee a Total birds per 100 acres. 22 9 138 92 24 | 203 152 Number of species... 10 Z 10 8 6 26 15 446 no value to these open-field birds, and they were surely favored by the habitat changes that came with mechanical harvesting. In 1906-07, the cut fields, which should pre- sumably have been good habitat for the lark, had poor populations of these species. The winter data, like the data for sum- mer, indicate that the lark population in- 1906-07 and creased greatly 1956-57. In cornfields of all types combined, at least 38 species of birds were found in the winter census transects, tables 44 and 45. As already indicated, the cornfield avi- fauna was an interesting combination of prairie and shrub or forest-edge species, the shrub species being particularly prom- between I_ttinors NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 inent in southern Illinois and in the hand- picked fields of the first survey. For most of the winter birds, cornfields must be a marginal foraging habitat, for few species were found with great regularity in these fields. The tree sparrow was recorded in cornfields in all years and all zones except the northern zone in 1957-58 (in me- chanically picked cornfields). Other im- portant species of this winter habitat, from the standpoint of numbers of individuals “seen or frequency of sightings, were the crow, junco (southern zone), and mead- owlarks (southern zone) in most types of cornfields; the mourning dove, bob- white, and chickadees in hand-picked corn- fields; and the Lapland longspur and Table 45.—Winter avifauna in Illinois harvested cornfields (birds per 100 acres) as determined strip censuses in the three zones. The 1906-07 figures are for fields in which cornstalks had been t by hand; figures for the other years are for fields mechanically picked. Figures in parentheses in- sate numbers of acres censused; + indicates less than 1 bird per 100 acres. SPECIES orned lark ate-colored junco ipland longspur._. ree sparrow_. -dwinged blackbird eadowlark (species?) arling i isty blackbird isha ane ymmon crow. rickadee (species?) owny woodpecker ourning dove ardinal ouse sparrow ybin ybwhite astern bluebird arolina wren . merican goldfinch ellow-shafted flicker 2d-bellied woodpecker. ng sparrow yarrow hawk ing-necked pheasant ufted titmouse. .ort-eared owl larsh hawk ed-tailed hawk avannah sparrow . nidentified bird - otal birds per 100 Ura umber of species... 1 NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE 1906-07 | 1956—57 |1957—58 | 1906-07 | 1956—57 | 1957—58 |1906—07 |1956—57 | 1957-58 (90) (308) (21) (107) (491) (268) (60) (154) (123) 14 9 2 90 24 a 25 15 alt. ae rah 47 26 94 18 oe 107 42 pies et Et 5 9 11 6 + 40 3 2 ah she pes 57 i wots os 5 28 8 ao tee.) + ike 26 1 1 ee bs Rte 10 10 oR: 1 2 is cee 14 1 2 1 ae 5 ie 1 4- 1 a 5 v) ‘s : 1 + 7 “ag i 3 3 2 ast he 8 if ug E 1 3 2 s i ae 5 1 4 sr a= - ---- 1 + Es 2 1 2 oe 3 1 1 1 st a Zz 1 1 =f 3 i ue Bas. 2 ES Els 1 a 4 Wh 1 E ee + = eS a en poe e 9 50 9 24 207 76 152 188 163 2 12 1 6 12 11 15 13°) ee PES —=————— October, 1963 GraABpeR & GRABER: horned lark in mechanically picked corn- fields. Soybean Stubble (Winter) The tremendous increase in acreage of soybeans after 1920 has already been dis- cussed. All but 21 of the +97 acres of bean stubble censused in winter were covered in the second census period, table 43 ; some or all of these 21 acres may have been stubble of field beans. Most of the soy- Birp PopuLations IN ILLinors 447 bean acres censused were in central Illinois. As a winter bird habitat, soybean stub- ble fields were more like cornfields than plowed ground and supported a similar avifauna. he average bird populations in the various zones and census years varied from almost zero to 3.9 birds per acre (4 to 387 birds per 100 acres, table 46) ; the populations were highest in the south- ern zone of the state. Table 46.—Winter avifauna in Illinois soybean stubble fields (birds per 100 acres) as de- termined by strip censuses in the three zones. Figures in parentheses indicate numbers of acres censused. NORTHERN CENTRAL SOUTHERN ZONE ZONE ZONE SPECIES . 7 1956-57 1956-57 | 1957-58 | 1956-57 | 1957-58 (28) (187) (135) (58) (68) Ie lorena) ie ee SNS SS a a + | 52 43 60 ia Redwinged Rapipirdees 2s te os bs 293 Meadowlark Sess fi) Sa is ay ae Ee: 98 Ae. Lapland Lal ati sien Bee Ad eB 70 3 = 12 Mp unnineedoviesmere 2 ek le 50 Canada goose _ AN Aa Deg hoe eA. | 17 American goldfinch _ A os Ae : 3 1 House- sparrow... Plies eae 2a pee 3 Slate-colored ee POUR TE PNT ites Fes | 3 3 Red-tailed hawk _ & A 2, Common crow_. 2 tes Red-bellied woodpecker... 1 ee Savannah sparrow pts Jou a = 1 Total birds per 100 acres - f | 124 47 233 387 Number of species 1 3 3 a 6 Table 47.—Winter avifauna in Illinois plowed fields (birds per 100 acres) as determined by strip censuses in the three census zones. Figures in parentheses indicate numbers of acres censused; + indicates less than 1 bird per 100 acres. NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE SPECIES 1906-07 |1956—57 | 1906-07 | 1956-57 |1957—58 | 1906-07 | 1956-57 | 1957-58 (269) (68) (125) (46) (40) (18) (43) (50) more dplanke: 2.02 ee. 38 6 8 183 30 84 2 Slate-colored junco aa vee zed Ed 22 fo fae 2 ats eel Lapland longspur 1 6 9 ee oe ate iss fouse sparrow. | 6 BE: 5 ae Betmlumoen. ee 1 = Zz Chickadee (species?) ros 2 as (irecerspannowe 1 Yellow-shafted flicker __ + oe Ss aeeee Tdawk= (‘spectes?), 2-22-20). 2. es te | Sf thle eaten ad 548 is Total birds per 100 acres 46 Ls 32 192 ie) 16 36 2 Number of species 5 3 3 2 2 1 2 1 448 Of 13 species recorded in soybean fields, only the horned lark was found in all census winters and regions. Plowed Fields (Winter) In the two census periods, 659 acres of plowed fields were censused in winter, table 43. For the various census years and zones, the bird populations varied from almost zero to 1.9 birds per acre (2 to 192 birds per 100 acres, table 47) ; the average was about 0.5 bird per acre. Populations averaged highest in central Illinois. In the southern zone, there was a striking difference between the bird pop- ulations of this habitat and those of corn- fields. Birds occurred in much greater numbers and variety in corn stubble than in bare plowed fields, tables 45 and 47. Ixtinors NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 At least nine species of birds were re- corded within the plowed field transects in winter. The dominant species was the horned lark. The absence of cover ap- pears to favor the horned lark; this one species comprised about 83 per cent of the statewide winter bird population seen on plowed ground. The Lapland longspur was recorded frequently in this habitat. Small Grain Stubble Fields (Winter) In terms of acreage, small grain stubble fields (wheat, oats, barley, rye) consti- tuted the third largest winter habitat cen- sused, table 43. About one-half of the 1,249 acres censused were covered in 1906-07. In the fields censused in winter, the stems of harvested wheat, oats, or other Table 48.—Winter avifauna in Illinois small grain stubble fields (birds per 100 acres) as deter- ned by strip censuses in the three zones. ed; ++ indicates less than 1 bird per 100 acres. Figures in parentheses indicate numbers of acres cen- CENTRAL ZONE SOUTHERN ZONE 1906-07 | 1956-57 | 1957-5. (235) | NORTHERN ZONE SPECIES 1906-07 |1956-57 | 1957-58 (223); (N71), C20) rling_. EES | | fee 21 EB; bland longspur__ py aieed Bel 72 19 aot red lark * 12 3 34 adowlark (species Res + 2 MInOn ero yw 2 24 1 CO GLY Yeeeah ae 2 eae Be sparrow 22 + 14 ip Sparrow 2. oo a amp sparrow. ywn-headed cowbird__ aly Hse Sparrow =: 2 a urnine dove 5 Conte’s sparrow__.. re fe oe ig-necked pheasant_____ 1 5 stern bluebird. b rannah sparrow_______. Z “ irrow hawk ; asm low-shafted flicker 1 rt-eared owl. rkey vulture 502 3 E i-tailed hawk... 1-bellied woodpecker_ wny woodpecker___._____ ygerhead shrike_._._ te-colored junco_.._ ea oa Sh ee ea ce + wid wk (species?) shes = ae identified bird... an + se tal birds per 100 acres.| 113 48 55 mber of species. 8 7 3 1906-07 | 1956-57 | 1957-58 (137) | (131) | (205) | (54) | (70) ae 38 i 251 9 ? 54. cS Ae Ky a 20 20 16 12 oS 3 wa 9 3 25 80 i 9 1 18 1 = ne 4 : : 22 ay a 1 3 1 6 2 Bes fs 4 9 7 v2 : 3 1 6 11 re he i 19 5 3 ee 4m bs : 1 2 : 5 ie Ny oe : E 4 < ag a ; 4 oy 1 : 1 wa an 1 Be, + F + = sik as ee 1 Ge a 1 : 3 1 ; ad E 1 sake 1 3 Ki e 1 cae re i ox ; Me i. nee ei 1 2 40 387 81 85 382 31 8 5 7 17 9 es ee Se October, 1963 Graper & GRABER: small grain, along with grass and weed growth of varying amounts, usually formed a fairly dense ground cover 6-12 inches in height, though often with some bare ground between rows. Winter bird populations in this habitat were at least as variable in density as those in row crops and plowed fields. Popula- tions in small grain stubble (all years and zones) ranged from 0.3 to 3.8 birds per acre (31 to 382 per 100 acres, table 48). In the second study period, populations averaged about 0.5 bird per acre in the northern zone, 0.8 in the central, and 1.8 in the southern. No consistent differences were apparent between population densi- ties of 1906-07 and those of 1956-1958. In the two study periods, at least 26 species of birds were identified within census strips in this winter habitat; the most varied avifauna was found in the Birp PopuULATIONS IN ILLINOIS 449 southern zone, table +8. Species recorded in this habitat in the largest number of census winters and zones were the horned lark, crow, meadowlarks, and tree spar- row. Species recorded less frequently but in relatively large numbers in some years were the Lapland longspur and starling. Small grain stubble is not a particularly important habitat for any species of bird, but it probably serves regularly as a mar- ginal foraging habitat for most of the species listed in table +8. Meadowlarks, which in Illinois wintered regularly in the row crops and plowed fields only in the southern zone, were found in small grain stubble fields even in the northern zone. Wheat Fields (Winter) Winter wheat is grown principally in the southern and central zones and in rela- Table 49.—Winter avifauna in Illinois wheat fields (birds per 100 acres) as determined by strip cenuses in the three zones. Figures in parentheses indicate numbers of acres censused; + indicates less than 1 bird per 100 acres. No wheat fields in the northern zone were censused in the winter of 1957—58. NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE PEEerEs 1906-07 |1956—57 |1906-07 | 1956-57 |1957-58 | 1906-07 | 1956-57 |1957-58 (57) (21) (203) (125) (112) (335) (163) | (130) mornedtarke. Se. 222 66 1 21 37 4 24 2 Wicee sparrow. eee ae 2 24 wee Lapland longspur__._-__-—> — 5 2 is 15 Meadowlark (species?) 3 15 1 “Sid a Sa a A 12 1 Commonicrow= 7 1 1 1 Slate-colored junco_____~ ts 5 5 be House sparrow... _ es | 3 4 American goldfinch we 5 1 eamadiaye OOS. | ad, 4 Eastern bluebird __.___ <= 3 Sparrow bavwk 22-2 - 1 1 Mourning dove see - 2 Brown-headed cowbird__ so 3% B On paspalrrow 2 + + se Mviarshi hay k= 1 ullaleer eee io 1 Mocking bird. 3c. = 2 1 aos LOUD in ge ee ee ee eS 1 Dian] Ne ea Si ee ae 1 se Siinkeyavulture: 2 ee: + Rough-legged hawk... = m= Lutted titmouse —_______.__. | ie o Unidentified bird das, a) eo ee bez + Ene |p ee Total birds per 100 acres __ 73 LOH OEE pedo | 41 20 66 20 Number of species 2 2 | 8 Sree peas 10 5 450 tively small acreage in the northern zone. In the two study periods, 1,146 acres were censused in winter, table 43; the acreage was distributed about equally between the two census periods. In winter, the cover in this habitat is a short (3—5 inches), dense stand of green plants. In the thickest stands, the mat is uniform and has no bare soil between rows, but in most fields some bare soil is Ittrnois NAruRAL Hisrory SuRVEY BULLETIN apparent between rows. Bird populations in winter wheat fields were generally low; the densities in dif- ferent census winters and zones ranged Vol. 28, Art. 3 from 0.1 to 0.7 bird per acre (10 to 73 birds per 100 acres, table 49). The num- bers of birds in the central and southern zones were roughly comparable. At least 23 species of birds were counted in the census strips of this winter habitat, table 49. The horned lark was the most abundant and most frequently sighted spe- cies. The Lapland longspur and tree spar- row were less numerous in this habitat than in the harvested cornfields, table 45. The distribution of the meadowlarks in this winter habitat was similar to that in soybean stubble; that is, the birds were Table 50.—Winter avifauna in Illinois pastures (birds per 100 acres) as determined by strip cen- es in the three zones. Figures in parentheses indicate numbers of acres censused; nl bird per 100 acres. + indicates less SOUTHERN ZONE NORTHERN ZONE CENTRAL ZONE SPECIES | 1906-07 | 1956-57 |1957—58 |1906—07 |1956—57 | 1957—58 |1906-07 | 1956-57| 1957-58 — (440) (83) (26) (343) (38) (118) | (208) (27) (66) rned lark_. se aay i 6 12 AGEN os a 22 13 62 6 dwinged blackbird _ bans 1 am ae on en 109 of te-colored junco.___. 6 Ent 6 14 a 76 Die As9 oz sie Sen ae 84 1 lerican goldfinch 22 35 ae aie ete 11 Ree stern bluebird + in 7 ci 61 ML ep) ses srs eS ie : 1 ee. se 51 is ‘adowlark eren = ee 1 aa Bu z 9 4 30 ee Sparrow - 7 8 tS) 1 5 1 4 1 mmon crow - 6 6 3 2 15 am use sparrow __........_. 14 1 8 = 7 aay rple finch Sa 17 3 rdinal : st ws 4 2 5 A “ Kee ae llow-shafted flicker ___| + | 3 4 1 pwihiite 227 ce ten eos oat 9 dar waxwing __ 5 v2 8 ChE 2eeom ee 1 ash — 5 te 2 {-beilied woodpecker Z ae 1 2 2 1 ickadee (species?) . + 1 zeit ig sparrow... 1 = 3 urrow hawk 3 1 as 2 mmon grackle zak ae 4 pss pland longspur __. 1 1 mee 1 rkey vulture. = 3 ae ick vulture 2 a 1 {-tailed hawk. us 1 : SSParLow sion ths Lae soe 1 e wny woodpecker + + ope ae i-shouldered hawk _ er sue + —= lite-breasted nuthatch - + tes 25 irsh hawk nat | — 2 iry woodpecker + | a Awe : wk (species?) ~ | ae identified bird se Be hes ae ie. 2 + 4 ae tal birds per 100 acres. 67 L/, 31 82 34 De, 85 359 181 mber of species.) 1 3 14 5 10 10 11 Ayes i lad ee ad cea ey pees tes October, 1963 Graper & GRABER: restricted to the southern zone in these habitats, although they had a more north- ern distribution in small grain stubble and some other habitats with taller cover. Pastures (Winter) In the two study periods, 1,350 acres of pastureland were censused in winter, most of them in 1906-07, table +3. Most of the pastures censused were stands of bluegrass with a few scattered, low woody plants. The grass cover was dense, even in winter, and 3-8 inches in height. Table 51—Winter avifauna in Illinois fallow fields (birds per 100 acres) as determined by strig Birp POPULATIONS IN ILLINOIS 451 Bird populations of pastureland in dif- ferent census winters and zones varied from 0.2 to 3.6 birds per acre (17 to 359 birds per 100 acres, table 50) ; densities were lowest in the northern zone, highest in the southern. Population densities in pastureland varied less from zone to zone in 1906-07 than in 1956-1958; popula- tions in the southern zone were conspicu- ously higher in 1956-1958 than in 1906-— 07. These data reflect a general trend: an increase in winter bird populations of southern Illinois since 1906—07. censuses in the three zones. Figures in parentheses indicate numbers of acres censused. SOUTHERN ZONE NORTHERN ZONE CENTRAL ZONE | SPECIES | 1906-07 | 1956-57 |1957-58 ae A ach 1957-58 | 1906-07 | 1956-57 | 1957-55 (59) (28) Gy Ye ha i ae Os) (34) (114) (52) (51) ee == oi [esas SI ES il te ta es Slate-colored junco | 26 a oe 78 ati eed 14 193 39 sree sparrow 28 x 91 21 18 95 70 12 2 8 18 Bobyphite ess Las / el 33 16 33 wa) 129 Shiai Wha Veco ace ee 14 we sa =e 52 + American goldfinch bis 5 ee ae 8 43 Momnmedelankews 1 eo. 7 24 5 9 3 od Song sparrow... 9 15 oe 18 Meadowlark (species?) _ 3 31 6 Cardinal Ve Se ees es: 12 6 6 10 Chickadee (species?) 21 Ai Eon 4 2 Ring-necked pheasant —_ 14 1 - 58s = Swamp sparrow... : 1 Z 18 Field sparrow... | et Eastern bluebird ie sn 3 12 Downy woodpecker. 3 6 3 i= ae Le Conte’s sparrow. 4 8 White-throated sparrow aoe tase, ~ 10 Red-tailed hawk 4 ee, 1 Bi) House sparrow. AoA S 5 2 EAA 7 2 Red-bellied woodpecker ~ = 1 2 2 Common crow... = vee yi 2 2 Sparrow hawk... a 4 fs: 2 ae Mourning dove <3 a he é : as Mockingbird. as es 4+ Short-eared owl 2 A nee Yellow-shafted flicker __ 2 abe Carolina wren... : 2 Long-billed marsh wren _ 2 se eA p ITN eien ee ee tae Po 2 é seek 2 Loggerhead shrike M Z = White-crowned sparrow_ A eet 2 MOXA SANT OW a ae ae | cet 2 Hairy woodpecker _ 1 RSE my ayes ee rx i 1 = _ Melospiza (species?) 6 a Unidentified bird. 2a cl = ae ae 3 1 Z 2 Total birds per 100 acres 141 68 60 233 | 103 54 61 373 | 311 Number of species 4 7 6 6 3 16 2 iie | ak 452 In the two census periods, at least 32 species of birds were recorded in census strips of winter pastures, table 50. The horned lark was the dominant species, oc- curring in all census years and zones. In our data, there is a suggestion of winter habitat change for this species. In 1906— 07, population densities of the horned lark were consistently higher in grassland habi- tat than in row crops, while, in the second study period, the lark population was higher in row crops and plowed fields than in grassland. Other species prominent in winter pasture were the junco, goldfinch, meadowlarks, tree sparrow, crow, and cardinal. Fallow Fields (Winter) Fallow fields, cultivated fields that have been deserted, make good winter bird habitat, supporting a variety of spe- cies and large numbers of birds. Only 434 acres of fallow fields were censused in winter, about half of the acre- age in each census period and half of it in the southern zone, table 43. Winter bird populations in fallow fields in the different census zones and years varied from 0.5 to 3.7 birds per acre (54 to 373 birds per 100 acres, table 51). Highest populations were in the southern zone and lowest in the northern. In the northern and central zones, populations were conspicuously higher in the early study period, but, in the southern zone, they were higher in the later period. The same trends were apparent in winter bird populations of pastureland. These popu- lation differences between 1906-07 and 1956-1958 may be attributed largely to fluctuations in numbers of the junco and the tree sparrow and to a general increase in the winter bird population of southern Illinois since 1909. In the two study periods, at least 34 species of birds were counted in winter census strips through fallow fields, table 51. Only the tree sparrow occurred in all years and all zones. The horned lark oc- curred in this habitat frequently, but in limited numbers. Other common species were the junco, bobwhite, and song spar- row. In southern Illinois, the meadow- larks, cardinal, swamp sparrow, and red- bellied woodpecker were among the spe- cies found in every census year. ILtino1is NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 Hayfields (Winter) Hayfields present a varied picture in winter, as the fields have been cut at various times in the previous summer or fall. Fields with short growth have an abundance of bare ground and are at- tractive to such species as the horned lark and Lapland longspur. Well-grown fields with taller (at least 8 inches), more dense cover probably favor other species, such as the meadowlarks and bobwhite. In the two study periods, 873 acres of this habi- tat were censused in winter—about half of the total in each period, table 43. Quantitatively, winter bird populations in hayfields compared roughly with those in mechanically picked cornfields, tables 45 and 52. In the different zones and cen- sus years, populations varied from about 0.1 to 2.0 birds per acre (7 to 202 birds per 100 acres, table 52). As in most other habitats, populations in hayfields averaged highest in the southern zone, lowest in the northern. They averaged higher in late than in early censuses, at least partly be- cause of greater numbers of horned larks. At least 23 species were recorded in this winter habitat, table 52. The horned lark was the principal species; the mead- owlarks and Lapland longspur occurred in large numbers in some zones and years. Shrub Areas (Winter) Shrubs comprise a rich habitat for birds in winter. The shrub areas (including edge shrubs) censused in the two study periods harbored dense populations and a variety of species. Only 239 acres of this habitat were censused, all but 51 acres in 1956-1958 and more than half of 1paeaae the southern zone, table 43. Bird populations in shrub areas in the different zones and census winters varied from 2.0 to 16.2 birds per acre (203 to 1,616 birds per 100 acres, table 53). Highest densities were in the southern and northern zones and in recent years. Sam- ple sizes, which were small, may have tended to exaggerate the population den- sity data. However, the 1906—07 census — in this habitat consistently indicated mark- edly lower populations than those of the more recent census. To some extent, the apparent population differences between 1906-07 and 1956-1958 reflect actual population increases in a few species (for 3 Faces October, 1963 Graper & GRABER: example, the cardinal) and also a general trend, observable in a number of species (for example, the mourning dove), for birds to winter farther north in larger numbers in the second than in the first survey period. At least 42 species of birds were found in shrub census strips in winter, table 53. Among those recorded in several censuses and in large numbers were the tree spar- row, junco, house sparrow, cardinal, bob- white, and starling. Birp POPULATIONS IN ILLINOIS 453 100 acres, table 54+). The populations averaged higher in the southern than in other zones. In the northern zone, the 1906-07 population was much lower than the populations recorded for recent years. In the two study periods, at least 48 species of birds occurred in the forest strips censused in winter, table 54. Among spe- cies found in several census years and zones were the junco, tree sparrow, chick- adees, blue jay, cardinal, tufted titmouse, crow, goldfinch, red-bellied woodpecker, downy woodpecker, white-breasted nut- Forests (Winter) hatch, song sparrow, and hairy wood- The Illinois woodlands censused in win- pecker. The bobwhite, Carolina wren, ter were very rich in species and also in robin, red-headed woodpecker, and yel- numbers of birds, table 54. In the two study periods, 764+ acres of forest or woodlands were censused in winter, about 400 of these in 1956-1958; the largest acreage was in the southern zone, table 43. Total bird populations in different cen- sus winters and zones varied from 0.4 to 3.9 birds per acre (45 to 394 birds per low-shafted flicker were among the spe- cies found in every census year in the southern zone of Illinois. Comparison of Data for Winter Habitats Partly because of a breakdown in ter- ritorial behavior that occurs in winter, Table 52.—Winter avifauna in Illinois hayfields (birds per 100 acres) as determined by strip cen- suses in the three zones. Figures in parentheses indicate numbers of acres censused. NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE SPECIES 1906-07 | 1956-57 | 1957-58 | 1906-07 | 1956-57 | 1957-58 | 1906-07 | 1956-57 |1957-58 en (Gli723) (145) (37) (164) (134) (46) (90) (54) (31) noted lark 2. pe 21 38 4 34 71 2 6 26 Meadowlark (species?) | | 8 at ae 1 aS. 55 22 68 Lapland longspur_-__--__- 11 tee all 110 ore fae 6 Babyibites Pig seas ae ee aes ae 20 aes 29 Slate-colored junco = ass | 2 6 Si cae Eastern bluebird at ni 9 20 Sprague’s pipit_____________.. eae ee as we ws ae Ze 13 13 ‘Si etl [n ae ae teers: 1 i= am 1 21 as Mourning dove —....-_- =: an aes oe 1 ea fe oe 23 epiidlee ree es, Pode ae Petes —- pe =e EAS, i 5 18 American goldfinch 1 1 13 Micee sparrow... |... | 2 + os 1 = Common crow ——...-_..___-. 3 1 1 ies Song sparrow _ eb: zee 1 = =o 2 Yellow-shafted flicker his ew ne me 1 1 | 7: TE Vine eee. eA ae 2s ie eS 3 Chickadee (species?) ie ee Be me ae es 2 ae Turkey vulture... Oe Sie el i eae 2: nes 22. aS 1 2 Rough-legged hawk... ae Ses ele 1 Sparrow hawk____.._---.--.. aia se ee ee: 1 Ring-necked pheasant Ay Ayes 1 | Downy woodpecker oak 1 House sparrow —____----- | 1 es ee 2 ae pas aa Hawk (species?) -__---. | as ae = 1 ae Eel 1 why ete Total birds per 100 acres. ri 50 38 13 5S 202 89 118 185 Number of species 4 10 1 7 7 3 8 df 7 454 Ixtinors NarurAL History SuRVEY BULLETIN bird populations at this time of year tend to have a definitely “clumped” distribu- tion. At this season, large areas of a par- ticular habitat may be void of birds, while the bird population of the habitat may be Vol. 28, Art. 3 flocked in relatively small areas. At this season, also, birds tend to range farther and to be less restricted to a particular habitat than in summer. The avifaunal characteristics of a given habitat are thus Table 53.—Winter avifauna in Illinois shrub areas (birds per 100 acres) as determined by strip censuses in the three zones; the figures include edge shrubs. Figures in parentheses in- dicate numbers of acres censused. oy ee ey re | /NoRTHERN ZONE | CENTRAL ZONE SOUTHERN ZONE seen Ss eee SPECIES 1906-07 |1956-57 1956-57 1957-58 1906-07 1956-57 |1957-58 (IBY gS 1 ( 39) (8s) eae | (60) | (41) i a oe : | 2 gece 9) ‘Tree sparrows. . 1,002 460 301 9 191 113 Slate-colored junco__. cae mea 136 73. oes 681 Riptisesaparro ys ee | 143 69 42 91 rf BO Oy ibe se er ee es 62 [ety yee 14 112 73 £2 Cardinal. 2 ve ee ee ee 18 52 3 98 83 Starling . 25 i Wsgseed Pree £23 100 12 Mourning dove rae Chee 20 240 Redwinged hluckbird ie 290 = Robie oe st Soo eee ; Bi ee (iene 87 39 Chickadee (species?) | 45 15 9 9 12 25 Cedariwaxwing ee See eee Soek 124 ane Bae at UIE Ave ey ees as a OS | 5 3 Eat 8 12 NONE Bparroy se os oe ay So pl 5 bade 6 45 47 White-crowned sparrow. ogi, ne skis 101 2 American goldfinch 2 ae ie 30 66 Downy woodpecker.........__...._______ 11 15 6 3 13 5 Red-bellied woodpecker _ yin Seg Z 9 3 18 15 Brown-headed cowbird on (on gia 52s obe: 50 ma astern tiaebinid . ora oe ey: | 7 21 5 White-throated sparrow... 28 7 Mocking indi eta. 5 5 es ua 3 29 Purple finch 3 Sad i oe 27 Si 3 Connon Crow ee of 2 3 MOR AD ALTO Oise oe eel arte a gees 9 7 ei Carolina “wrens se es 3 7 5 Rufous-sided towhee ze} 3 7 5 Swamp sparrow.c2 22" ea ae 7 7 aburtted titmovse. 2s ee es aes 2 3 6 2 é Hairy woodpecker. 2) [ores ag Field sparrow pitas : ites 5 5 White-breasted oraaieh etek dee eases 3A) 6 oe 3 Long-eared owl 2) ot | 2 6 ‘ oe be Yellow-shafted flicker | eal 2 5 Loggerhead shrike Cradle Ta / | a 2 5 Meadowlark (species?) BAS The a 7 Be Ruby-crowned kinglet | i 2 2 Wiyrtle warbler a3 ee toe | ay 2 2 PLagtin Sparrows er) 3 RE Be WMiaralvitawik vi 2 oat is Po | ey 2 Sparrow lawk 225 oe ea 2 ais saw-whet owl oot js ape Hermit thrush. : “2 E Melospiza (species?) ___ 2S 8 ‘ Zonotrichia (species?) ue ¢ Unidentified bird oe Bat ietee es: 32 3 bey 28 20 Total birds per 100 acres 203 ‘1,612 780 860 | 314 1,616 1,451 Number of species... | 6 OR ME Oeil PR ar egrP 26 , October, 1963 Graper & Graper: Birp PopuLatTions IN ILLINOIS 455 Table 54.—Winter avifauna in Illinois forests (birds per 100 acres) as determined by strip cen- suses in the three zones. Figures in parentheses indicate numbers of acres censused; + indicates less than i bird per 100 acres. NORTHERN ZONE CENTRAL ZONE SOUTHERN ZONE l | og 1906-07 1956-57 | 1957-58 | 1906-07 |1956-57 1957-58 1906-07 | 1956-57 |1957—58 (65) | (24) | (21) | (50) | (66) | (86) | (241) | (120) ] (91) Slate-colored junco a 96 24 ae 14 52 68 a5) (029 siree sparrow. = 6 92 28 59 157 3 9 Ze American goldfinch — 21 97 44 1 3 =- 7 aid (ommon crow. 12 il 20 8 81 7 5 3 8 Chickadee (species?) 9 8 44 6 9 12 15 18 18 Perec tetas ts ze 8 nts 6 14 13 10 27 37 LT a 1 re 19 2 23 8 29 7 18 shutted titmouse.. mes 4 5 2 11 16 24 20 11 mepiyyitite oP aan ba Pe al 18 eg (8) 12 25 Red-bellied woodpecker __ 1 4 15 2 4 10 5 12 7 Downy woodpecker 9 4 10 2 1 7 3 7 11 White-breasted nuthatch_ 3 4 10 16 = cya 2 2 2 Sone: sparrow —.- = aus ad 15 Edt 6 1 ay 2 1 12 Warolinaiwren 2 2 Sia 4 13 7 White-throated sparrow - a 7 E 20 House sparrow___---- ee 21 Ces Make 1 2 an 2 a. Wanada'goose- —_ zi zal = Be chu hs nae 26 “Selif Via eee as: aw =e aS 1 ule — 24 ees Obie ae at eS 3 1 1 12 10 Eastern bluebird_.______. 15 9 zz Siurkey vulture... =. Bn 24 es ee Red-headed woodpecker_| __ ial = rs 3 1 2 15 Hairy woodpecker________ 3 o Sea! 2 6 3 3 2 Mourning dove — 4 omy ee 1 ae Se 14 = Yellow-shafted flicker mes ee abe ed ae 1 Z D i Red-tailed hawk a 4 1 4 Been leans ek ~~ 9 Purplepinehes 2 3 5 Rufous-sided towhee______ ms mo a es But au 3 25 3 Yellow-bellied sapsucker_ oe ws nN ee ie sb ue 1 4+ Swamp sparrow. 1 ae tb = #2 Ses Ls 1 1 Long-eared owl ___________-- ee ee ee! 2 =F Myrtle warbler... ee ice ahs fe a 2 Red-shouldered hawk ae 1 1 es brown creeper. | 1 =e 1 veld) sparrow. ee ce = a veh = ay) 1 1 Winter wren. cad es cy cele a = we 2 ae Mioekino bind. 728 2 oe a aie se we eS 2 Sparrow hawk Bee ote Ds = coal ce 1 awe Great horned owl... ci ty yh oe ae — = 1 a: Belted kingfisher ran ee sek Se ee ae is Bes 1 Pileated woodpecker. PAs uae es Lie ee eee 1 er a Rermitthrush. 222 ce. pl coh sa ae ay een Sed i 1 Golden-crowned kinglet _ 2% s Ee eda = 1 ae se ee Meadowlark (species?) | __ js bos mah = a ee 1 Redwinged blackbird bi at. on eke wel aa ea a ee 1 osaSPALLOW es = ay os = = = eral a eee | Golden eagle Sew over te as aKe Dd eis se pi! Hawk (species?) TG ee sick es nae = 3 wv: Dendroco pos (species ?) | sae aoe dy ee | 1 we Unidentified bird es pa ee Ses et Zit Vie eee 8 5 Total birds per 100 acres. 45 287 239 151 352 15, Ne 2SE. 255 | 2394 Number of species. | ple abe) hehe weg 2 18 19 32 33 26 456 less clearly defined in winter than in summer. Number of Birds.—Because winter bird populations in nonwoody habitats are generally very sparse in northern latitudes and high in southern latitudes, it is some- what misleading to discuss average winter bird populations for Illinois as a whole, but for comparative purposes it is con- venient to use a single figure to represent each habitat in the state. Mean density figures for winter bird populations in various habitats in the northern, central, and southern zones of Illinois are pre- sented in figs. 25-27. Average populations for the state, as shown by surveys in January, 1957 and 1958, were 54 birds per 100 acres in winter wheat, 63 in hayfields, 82 in pas- tures, 85 in plowed ground, 113 in small grain stubble, 135 in soybean stubble, 153 in mechanically picked corn, 206 in fallow fields, 289 in forest, and 1,325 in shrub- bery. To a very great degree, the Illinois avifauna depends on woody habitats. Still, the open habitats are probably being in- creasingly occupied by birds. For example, cornfields had an average January popula- tion of 48 birds per 100 acres in 1907 (stubble fields) and 153 in 1957 (me- chanically picked fields). Number of Species.—The variety of Illinois bird life in winter habitats tended to parallel the population densities in these habitats, but, more directly, it prob- ably reflected the complexity of the habi- tats. Plowed ground had the fewest spe- cies of birds (9), and soybean stubble, with only slightly more cover, had 13 species in the acreage censused, followed by winter wheat and hayfields (each 23) and small grain stubble (26). Hand- picked cornfields had 26 species and corn stubble or mechanically picked fields had 29 (this large number of species reflects, in part, the large acreage covered). No- tably more varied were the avifaunas in pastures (32 species recorded), fallow fields (34), shrub areas, including edge (42), and forest (48), tables 44-54. Statewide Winter Populations In summer, row crops and_ plowed ground (habitats that are characterized by large areas of bare ground) occupy more I]linois land than any other types of ILLiNnois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 habitat. In winter, because of fall plow- ing, these habitats are even more extensive than in summer. In the winter of 1906-07, there were 12,398,000 acres of row-crop stalks and stubble (corn, 10,500,000; garden veg- etables, 287,000 acres) and 1,611,000 acres of plowed ground, with a population of about 9,018,000 birds. About 504,000 (5 per cent) of these were horned larks, most of which were concentrated on plowed ground. By the winter of 1956— 57, there were 15,053,000 acres of row- crop stubble (corn, 8,939,000 acres; gar- den vegetables, 75,000 acres; soybeans, 4,- 785,000 acres) and 1,253,000 acres of plowed ground, with a state bird popula- tion estimated at about 21,448,000, of which about 7,502,000 (35 per cent) were horned larks. In all census winters, birds in these row-crop or plowed-ground habitats tend- ed to be concentrated in the central and southern zones. This concentration was particularly noticeable in the winter of 1906-07, when only about 217,000 birds were in cornfields of the northern zone, while 6,145,000 birds (76 per cent of the statewide cornfield population) were in cornfields of the southern zone. By con- trast, in 1956-57, about 1,339,000 birds (1957-58, 1,877,000) were in cornfields of the northern zone and 5,118,000 (43 per cent of the statewide cornfield popula- tion) were in cornfields of the southern zone. The data suggest that birds of the Middle West were _wintering farther north in 1956-1958 than in 1906-07, but to a large extent the data reflect a marae increase in the number of horned larks. Both the horned lark and Lapland long- spur favor the row-crop or plowed-ground habitats, and both are hardy species that survive well in northern latitudes. Para- doxically, while plowed ground and row crops were the poorest of the summer habi- tats (in terms of population density), they comprised some of the best of the nonwoody habitats in winter. Bird popu- lations in these habitats increased, partly from an expansion of the habitat and partly from an increase in population den- sity of certain species. This situation is a prime example of man inadvertently culti- vating a habitat for a particular species (in this case, the horned lark). ——_—e October, 1963 Graper & GRABER: In the winter of 1906-07, there were estimated to be 2,789,000 acres of small grain stubble in the state, with a bird population numbering about 2,078,000. In the winter of 1956—57, there were about 2,440,000 acres of small grain stubble, with a bird population estimated at 2,129,- 000. While small grain stubble is a good habitat for winter, most of this habitat is in the northern half of the state, and the bird species (meadowlarks and various na- tive sparrows) that make use of such cover have a more southern distribution, while the northern-ranging species (horned lark and Lapland longspur) tend to avoid tall, dense cover. In winter wheat, a consistently poor winter habitat, the 1906-07 avian popu- lation was estimated to be only about 455,- 000 birds on the 2,325,000 acres of this habitat in Illinois. In 1956—57, there were about 1,004,000 birds on the 1,639,000 acres of winter wheat in the state and, in 1957-58, only 486,000 birds on 1,787,000 acres. Pasture, which is a rich summer habi- tat, had surprisingly low bird populations in winter. In the winter of 1906-07, on about 6,085,000 acres of pastureland, there were about 4,936,000 birds. Reduction in pasture acreage (to 2,004,000 acres) brought the winter bird population in this habitat down to about 2,000,000 (1,761,- 000 in 1956-57 and 2,199,000 in 1957-— 58). The acreage of fallow fields in winter was reduced from about 1,496,000 acres in 1906-07 to about 1,034,000 acres in 1956-57, but, because of an increase in population density, the statewide winter bird population in this habitat was esti- mated to be higher in 1956-57 (2,618,- 000) and 1957-58 (2,114,000) than in 1906-07 (1,266,000). Hayfields in the winter of 1906-07 had a population estimated at only 1,460,000 birds on 3,245,000 acres. With increased acreage (to 5,254,000 acres), the popula- tion was estimated to be 3,601,000 birds in the winter of 1956-57. The woody habitats (shrub and forest) had very high bird populations in winter as in summer. In the winter of 1906-07, 469,000 acres of shrub-grown land had an estimated population of 1,422,000 birds. Though there was little change in acre- Birp PopuLATIONS IN ILLINOIS 457 age by 1956-57 (507,000 acres), the pop- ulation in this habitat was about 7,210,000 birds; the 1957—58 population was nearly as high (6,433,000 birds). Several species of birds were represented in this apparent increase between the winters of 1906-07 and 1956-57. The change may be further evidence that birds in the Middle West tended to winter farther north in 1956— 1958 than in 1906-07. Forest acreage increased from about 3,- 459,000 acres in 1906-07 to 3,996,000 acres in 1956-1958. The winter bird pop- ulation in forest increased far out of pro- portion to the acreage change, from about 6,654,000 birds in 1906-07 to about 11,- 079,000 in 1956-57, and the 1957-58 population was even higher (approxi- mately 12,985,000 birds). In all of these types of winter habitats censused in Illinois, there was a popula- tion estimated at 27,289,000 birds on 32,- 267,000 acres in 1906-07 and 50,851,000 birds on 31,927,000 acres in 1956-57. Even the lower population in 1957-58 (approximately 47,492,000 birds on 31,- 483,000 acres) was well above the 1906— 07 level. The difference in winter bird popula- tions between 1906-07 and 1956-1958 cannot be explained solely as annual varia- tion. There are probably at least two ma- jor causes of the increase: (1) actual population increases in a few species, such as the horned lark, and (2) changes in winter distribution of several species, with many birds of the Middle West wintering farther north in 1956-1958 than in 1906— 07. Much of the Illinois winter bird popu- lation was in the southern zone of the state. This zone, as we have defined it, includes about 15,947,000 acres of land (44.5 per cent of the state), which con- tained about 18,000,000 birds (65 per cent of the state population) in 1906-07, about 30,000,000 birds (60 per cent) in 1956-57, and about 32,000,000 birds (67 per cent) in 1957-58. The northern zone (8,778,000 acres of land or 24.5 per cent of the state acreage) had winter popula- tions estimated to total 3,500,000 birds (13 per cent of the state population) in 1906-07, 5,384,000 birds (11 per cent) in 1956-57, and 5,157,000 birds (11 per cent) in 1957-58. 458 The quantitative distribution of birds in the state in winter can best be observed in the mean density figures for each zone. Mean population densities (calculated number of birds in an area divided by the number of acres in the area) for all non- urban habitats in the three zones of the state in January, 1907, were 0.5 in the northern zone (0.7 in 1957), 0.7 in the central (1.6 in 1957), and 1.3 in the southern (2.1 in 1957). (Bird popula- tions in urban areas and urban acreage were not included in the calculation of the mean densities because we lacked winter data for this habitat.) The density of the winter population of birds in nonurban Illinois habitats increased between 1907 and 1957; the increase in the northern zone (about 41 per cent increase above the 1907 level) lagged behind that in the southern zone (about 64 per cent increase above the 1907 level). It should be noted here that there is a limit to the number of birds that can sur- vive on a given land area in a particular cli- mate. The January, 1907, population was presumably closer to saturation level in the northern zone of Illinois than in the southern zone. This saturation level may vary somewhat from year to year, but it is set within definite limits by climate, soil, land use, and other factors. How much more the winter population of IIli- nois birds may increase with the existing climate and agricultural situation cannot be predicted ; additional points of reference on this problem would be extremely inter- esting. Some additional impression of the influence of winter climate on bird dis- tribution may be obtained by comparing summer densities with winter densities in the three zones, fig. 28. In view of the mass migration of spe- cies from the state following the nesting season, the winter population of birds, when compared with the summer popula- tion, was surprisingly high. We estimated that in the winter of 1906-07 the popula- tion was about 30,936,000 birds on ap- proximately 34,917,000 acres (total land area of Illinois less urban and road-surface areas). [his acreage included some types of habitats not censused (such as home gardens, airports, and cemeteries) and is therefore greater than the acreage for the census figures on page 457. The estimated Intinors NATURAL History SurvVEY BULLETIN Vol. 28, Art. 3 JANUARY, 1957 ith JUNE, 1957 eet _——————————————— oO ooo _————————————— ————$———————————— Fig. 28.—Distribution of bird populations in Illinois in winter and summer. Hatching rep- resents density of the bird population in each of the three zones of the state. The numerals in each zone represent the mean number of birds per acre for all nonurban habitats cen- sused in the zone in January or June, 1957. population on the same acreage in the sum- mer of 1909 was 56,949,000 birds. We estimated that in the winter of 1956-57 the population was about 54,111,000 birds on approximately 33,672,000 acres (total land area of Illinois less urban and road-surface acreage). The estimated population on the same acreage in the following summer (1957) was 49,464,000. Thus, the winter population in some years may exceed the summer level. The size of the winter pop- ulations was particularly impressive in view of the fact that most I]linois birds in winter were in the southern half of the state, fig. 28. ACCOUNT OF SPECIES In four summer seasons (1907, 1909, 1957, and 1958) and three winters (1906-07, 1956-57, and 1957-58) in Ll- linois, 168 species of birds were identified in census strips. Nine additional species were identified outside the census strips. The census method was not intended to provide complete qualitative data on the avifauna of Illinois, but the list of species recorded, table 55, includes most of the species that winter or breed in terrestrial habitats of the state. Smith & Parmalee (1955) included 384 species in their check list of Illinois birds. Ninety-one of these are extinct or of only October, 1963 GrapeR & Graser: Birp PoPpuLATIONS IN ILLINOIS 459 Table 55.—Species of birds encountered in strip censuses in the three zones of Illinois; x indicates a species recorded within one or more of the census strips; * indicates a species recorded in the zone indicated but outside one of the census strips. | WINTER SUMMER | 1956-57 1907 1957 1906-07 and and and |} 1957-58 1909 1958 SPECIES | | fires heey ret vee eae eta [tee cu SR ee ona Boe ee eee pe ee sens Panne se tie .cr Pawo. atater vawee Ze LOY Cae OE 5 ZAR ee Shr, Horned grebe, Podiceps auritus________---.------------- Peg omy meth pit tere Perl re Great blue heron, Ardea herodias_...- ie large Hig aes twee * x |x x Green heron, Butorides virescens. |e ach op be Pea (UE en Dg) hr vee aid Pall oc! me <8! 19. Little blue heron, Florida caerulea a ek es, kate eee ope eet cel * Common egret, Casmerodius albus Ege Ares RCRA (Fe MB SG Wie it Sa x Black-crowned night heron, Nycticorax nycticorax.| = = |} x i, MEK Ce Least bittern, Ixobrychus exilis_____________. ES Mala oe wen fee Meet wr Hera) et ice ec x American bittern, Botaurus lentiginosus_______. POC e Oe ete carn Cael bone Naser BP SAD 6c Canada goose, Branta canadensis hy ee ee | ee = BiwessooseiGizen cacriulescens: ty herr nee ee a ow a Mallard, Anas platyrhynchos___----.----------- N98) POA! Ft 7 |e ae, See * Piack duck, vanas TUDripes. Cs Are Was S Fes Sr aan Blue-winged teal, Anas discors__________=» _----!--.-. ia NSPE tte bee Setar eRe NWWicodkduch = Aimisponsa eso Sarit wae Egy A Shem PH i Cag a essemscaup, Ayimyaapinis Sn PE ak | Sty aa * SA ae Turkey vulture, Cathartes aura... x # # x x 8x Black vulture, Coragyps atratus a > og eS eee rag eek ee Cooper’s hawk, Accipiter cooperii Neat JD i Bie sil xe Red-tailed hawk, Buteo jamaicensis.-- Xa | Ka oe Xe. 4% WK oak Red-shouldered hawk, Buteo lineatus_.--- = x x x * x Broad-winged hawk, Buteo platypterus_...-___ Sey fh ee Aang eas | ee 2 lg = a Rough-legged hawk, Buteo lagopus... xe aac as Ne 2 (Pr SE Golden eagle, Aguila chrysaetos 5a) ene ea (a eitee Se (ne Pe re bs Bald eagle, Haliacetus leucocephalus_.---__-___ a) Notion Pea Mic thw] Ieee mata tens Cee pT camer es Merrshihawk, Gucusicyaneus. x i dats la eral | 5 < 5 a Sparrow hawk, Falco sparverius__...-------- Seminole po Sar os leo ene > ellae.o bo rine. dys Greater prairie chicken, Tympanuchus cupido arin olay ears | canes LEE AS Bobwhite, Colinus virginianus_ > Sab ie al lub cena Efe cal b> Cages. chacleb l[bo Cs 10, ao.< Ring- necked pheasant, Phasianus colchicus____ Me nOK tT ae Ae eu eX foray pactridee, Perdix perdin | x alle iemnerratlekallwsy elegans. 2 Tae LEA Se lee, 5 hee |S Xe Virginia rail, Rallus limicola BF ein) Ba rh N | pe tl Dies ee SO RORe AGE CARO GE eee a NOES OF ee eek oe x ae Co NEES Common gallinule, Gallinula chloropus shy ay Cie eae Y Daeg ee a |g American coot, Fulica americana ae eS ys 5 el i SaaS ed | ke ans = Killdeer, Charadrius vociferus x Mar ltcee Ras, skys oy pa American woodcock, Philohela minor. SAN ee yo ite © beac ad SN es ev a Common snipe, Capella (OL ELAG 0a eee ee WO Ee he || Wee ee Ss een cha ee ne Ks Upland plover, Bartramia longicauda_ pe ea a kW Ee Sc a GEV a cao GIy 3: Spotted sandpiper, Actitis macularia_...-- ae cn | maine le Ss prado ahts cial L).< se HMemmnrsoull Larus angentatuse. Se aa Kel pe epee | ee Ring-billed gull, Larus delawarensis Lee ae S| yee de ee per | tea gk Black tern, Chlidonias niger —---___________ pgm toa ga le ies Prem ae ek |e here Rockdove, Golumba via ERak ie st alae ae aes SNA asa | ay oe Mourning dove, Zenaidura macroura Ka Xe eee OX Deiguto.eny| (to ey Fe. g me Yellow-billed cuckoo, Coccyzus americanus [fee pce me | a ee Sy i eK Ke Black-billed cuckoo, Coccyzus erythropthalmus oh pA gH SM Te xs FES ots Ue ok Great horned owl, Bubo virginianus Earhart sei PS VT a 36 Barred owl, Strix varia Bala “3 x x Long-eared owl, Asio otus reat atl x = aie Pact ge arate Intinoris NatrurAL History SuRVEY BULLETIN Table 55.—Continued | SPECIES WINTER Vol. 28, Art. 3 SUMMER | 1956-57 1906-07 | and 1957-58 Southern Northern Central Southern | Northern 1907 and 1909 - Southern Short-eared owl, Asio fammeus Saw-whet owl, Aegolius acadicus- Whip-poor- -will, Caprimulgus vociferus_____ Common nighthawk, Chordeiles minor__.__-.. Chimney swift, Chaetura pelagica_ Ruby-throated h ummingbird, Archilochus colubris Belted kingfisher, Megaceryle alcyon see Yellow-shafted flicker, Colaptes auratus ________. Pileated woodpecker, Dryocopus pileatus. Red-bellied woodpecker, Centurus carolinus___ Red-headed woodpecker, Melanerpes erythrocephalus oe Seas) Yellow-bellied s apsucker, Sphyr apicus v varius Hairy woodpecker, Dendrocopos villosus Downy woodpecker, Dendrocopos pubescens Eastern kingbird, Tyrannus tyrannus_—--_- Great crested flycatcher, Myiarchus crinitus___ Eastern phoebe, Sayorms phoebe — eae Yellow-bellied flycatcher, Empidonax flaviventris.. Acadian flycatcher, Empidonax virescens. Traill’s flycatcher, Empidonax traillii_.... Least flycatcher, Empidonax minimus Eastern wood pewee, Contopus virens Horned lark, Er emophila alpestris_. Tree swallow, Iridoprocne bicolor... Bank swallow, Riparia riparia. Rough-winged swallow, Stelgidopteryx etude Barn swallow, Hirundo rustica... eRe bias Cliff swallow, Petrochelidon pyrrhonota. a Purple martin, Progne subis.. Blue jay, Cyanocitta cristata _ Common crow, Corvus br aehor esther Chickadee, Parus spp. Black- -capped chickadee, ‘Parus atr icapillus Neos are Carolina chickadee, Parus carolinensis. Tufted titmouse, Parus bicolor. White-breasted Brown creeper, House wren, Tr Winter wren, Troglodytes troglodytes Bewick’s wren, Carolina wren, Long-billed marsh wren, Telmatodytes palustr is Short-billed marsh wren, Cistothorus platensis_ Mockingbird, Mimus polyglottos nuthatch, Sitta aE a Win daaltt Certhia familiaris oglodytes acdon Thryomanes bewickii Thryothorus ludovicianus Catbird, Dumetella carolinensis. Brown thrasher, Toxostoma rufum Wood thrush, Hylocichla mustelina Robin, Turdus migratorius_ Se eS | | Hermit thrush, Hylocichla guttata Swainson’s thru sh, Hylocichla ustulata | 4 tal a “ tal bal A FARK! tal aw i w ww KK bad enn KI HA RAK Kw RK “ ad a ' ' ' 1 \ ' ' 1 ' ~ eK OH “~ Ww ' A tal AK KA FAR A % | *A KR RA} A RA KA AK KR KARR KK KKK A 1 tal ” tal tal AR A KK : i Northern a ar w A 1957 and 1958 KrAK KA ~ A KR KA | | A AK rad Southern Ax RAK KI w eR Lege “ AK KK KK nA =, ee October, 1963 GrapeR & GraBer: Bird POPULATIONS IN ILLINOIS 461 Table 55.—Continued | | | WINTER SUMMER 1956-57 1907 1957 1906-07 | and and and | | 1957-58 | 1909 1958 SPECIES = =) a = 0) ceria ie ae SAMMI 1) Pe Sich Ty b= ff e\4 § 2/4 § e]B € = By Bice poet aie tei eae ZO a |e Aige ©) (ana Ane Or icon A Orcas Eastern bluebird, Stalia sialis______----_-_-------- x x reeee oe ip dtu an 4 hiordbiee> qin Blue-gray gnatcatcher, Polioptila caerulea saber h | Pan a oes eee igl fy een ks NBS cy Peco to: Golden-crowned kinglet, Regulus satrapa 3 * x xb wy bg ats eg Ruby-crowned kinglet, Regulus calendula... |) art ge Ps ena = Water pipit, Anthus spinoletta sp ee ae > a gis i ey ee Batapie s pipit,Anthus spraguei. ahs eal 42, Cedar waxwing, Bombycilla cedrorum ae pet Phe > Sens ees | eee ee ke Northern shrike, Lanius excubitor.-- pit Pama * hs Asap ml Niece ses ne Loggerhead shrike, Lanius ludovicianus XO #5 h5e-= |e -) Seines oko | wxkee «aN pe ELE SE OE a a aT ae br Sake rah ae eee sn (OG) < e. White-eyed VIE OM GET COmr GI ISEILS soe oe BEM ES ee Dy eS oiled RD x x Bell’s vireo, Vireo bellii_ ie Sse SEEM WR ES eG | tL pee Sa ee i Yellow- throated vireo, Vireo flavifrons ee Berean Py eee a Bs ee be eae oe eee eX Red-eyed vireo, Vireo Gin ae eee aie.) ome eas Pag ae Ub oe go] Oe ae yD Warbling vireo, Vireo gilvus = oiy rea me eave | eae eee eM] (op. S| eke a Black-and-white warbler, Muiotilta varia Es hn Lead rte ie * x Prothonotary warbler, Protonotaria citrea_____. aig 2) a, ete ee x x Worm-eating warbler, Helmitheros vermivorus_.}|_ — — |=2.%- ~|- = = x Swainson’s warbler, Limnothlypis swainsoni_. |} pe 5 het aoe ek Parulasvarbler Parula anvertcana SP x x Mellowawatbler, Dendroica petechta_.._ |) SS SS | x x oo ee Magnolia warbler, Dendroica magnolia asd ie Mile Sb Uh ea a x Ls alge Myrtle warbler, Dendroica coronata_-- x ez oy elles Cerulean warbler, Dendroica cerulea Meiipred nena) Wh pee AY yore Lae me me Lim 5 cpio 2 Wellow-throated warbler, Dendroica dominica...|_ © =|. 2 22 = = * Chestnut-sided warbler, Dendroica pensylvanica | ~~ | ~~ x Sey yee ty ae Pine warbler, Dendroica pinus LAA ee, a) Ne a as (erg RS aa ee aces) ee Ed Prairie warbler, Dendroica discolor eee ee oe Nee en pe Palm warbler, Dendroica palmarum BN RC gel ie ge x ay Rye Ovenbird, Seiurus aurocapillus Eee a are cgi eae ert hear era met | ct >.< Louisiana waterthrush, Seiurus motacilla_______ ee SE pare) || te eae x 33 MentuickyawatblersOporormls jormosus Se | eS Sy Se ae eX: Yellowthroat, Geothlypis trichas UGLY Be) ae rd ete se Ce eae cnr. G. Mellow=-breasted chat. Jcteria virens....- 22 ee pte eps x x Hooded warbler, Wilsonia citrina ___ cE oh PRE PN TE St Pd Ml A a rag Ra Ass oe x American redstart, Setophaga ruticilla.. Ci (ited CK Ce > tet chlo cates 4 ak > House sparrow, Passer domesticus Se xg) eu (ke econ |e seit | ye || ee ape an Ce Maleiniqemalnchonyx oryeiworus. 852 NS A ee ee oe xt 2x0 Meadowlark, Sturnella spp. eee NK Da lps ab ewe Oe Moc abe OTS illo ag ee Eastern meadowlark, Sturnella magna. -| ~ ~ - NA oA eae Peony oe ieee Ka Western meadowlark, Sturnella neglecta... IE RMN VS cats 5 Shan San Yellow-headed blackbird, Xanthocephalus__- UNEDOGE DUE GIUIS ee nee eae ee Sd eS SMES Ph 5 il geal ees eae | x Redwinged blackbird, Agelaius phoeniceus Be ae Se are Si ee de ce Orchard oriole, Icterus spurius S| pee eA oe eA ees IS ao ME Ah Cap. 3 Pima le Obiole, Lcleris Galena. 26 NS ef Oe a me Ko ke ak Rusty blackbird, Euphagus carolinus fl SP Area gs) xan lee a Pc eee gee Brewer’s blackbird, Euphagus cyanocephalus fy kn ae emeneine (Bike Chet agin [2 Bay || See Common grackle, Quiscalus quiscula — sue nees Sees Th >. Ho. Se ge db, Cars. Sol og eee >. Brown-headed cowbird, Molothrus ater SEI) Sh ee eae | Si Se ie > | ar ee oe Peaminttunacer np aranamalivated. tt 23 tt 8 ile a tea Niet / ol Ke 462 ILtinots NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 Table 55.—Continued SPECIES Summer tanager, Piranga rubra Cardinal, Richmondena cardinalis__.....-...- Rose-breasted grosbeak, Pheucticus ludovicianus__. Blue grosbeak, Guiraca caerulea Indigo bunting, Passerina cyanea Dickcissel, Spiza americana Purple finch, Carpodacus purpureus. American goldfinch, Spinus tristis Rufous-sided towhee, Pipilo erythrophthalmus_.... Savannah sparrow, Passerculus sandwichensis. Grasshopper sparrow, dmmodramus savannarum Le Conte’s sparrow, Passerherbulus caudacutus_. Henslow’s sparrow, Passerherbulus henslowii____. Vesper sparrow, Pooecetes gramineus.. Lark sparrow, Chondestes grammacus___ Bachman’s sparrow, Aimophila aestivalis._-_ Slate-colored junco, Junco hyemalis—....._. Tree sparrow, Spizella arborea : Chipping sparrow, Spizella passerina_.. Field sparrow, Spizella pusilla Harris’ sparrow, Zonotrichia querula White-crowned sparrow, Zonotrichia leucophrys White-throated sparrow, Zonotrichia albicollis Fox sparrow, Passerella iliaca Swamp sparrow, Melospiza georgiana... Song sparrow, Melospiza melodia Lapland longspur, Calcarius lapponicus Smith’s longspur, Calcarius pictus. Snow bunting, Plectrophenax nivalis | WINTER SUMMER 1956-57 1907 1957 1906-07 and and and 1957-58 1909 1958 Sf . £ |e 8 | 2 g © 2)8 £ $)3 2 Ee 2/3 2 3 2 oe ° oO S ° rt) S ° rt) S ° o 3 ZA OO D140 wo) B® Oral eee Mig peace eae A ae ae pie < x x |x x pene Lilie. coe et sey te, a = a eS x x x x = ss sil sat Be B x x x x x = = a = a ces x 6 x x x x x eS ok = = ee = x x x x p, x Ns p.€ x x x x x x x x x 2.6 x x x = x ae x x x = ts aE _ ae 2 a ».¢ 6 x x x Wel na X | 8) Se ee Pap. ar Na aera x blr < Yes Tr CS es ex eC a aa ha ee be ee, of. _ = x 2. x pth seg Ales Slit eRe nae x x Ks x x 6 ome x ae Rs ~ = 2 x x x x x x = = ES Be = Pea Mien i ak oc) Sc! x x D.< x x x x x x x - BS = x = a = a Se aS = x b =! po 2 = > x x a = a =. = x x 2x (2) Le x x xlsx © lx x x 2,4 ».@ x x 2:6 x x x x x x x x 4 as a Je =, ae LEE td pea |S" Ss Le Se x oot es pi. ne ae = a arr ax accidental occurrence within the state; about 110 species are of rare or irregular occurrence or present in the state only dur- ing spring and fall migration. Eliminating the migrants and the species of rare or accidental occurrence, we find that about 185 species of birds in the Smith & Parma- lee list occur fairly regularly in the state during either winter or summer or during both seasons. This number is close to the number in our list. During the 1906-1909 and the 1956— 1958 censuses, only nine species of birds, bobwhite, mourning dove, yellow-shafted flicker, downy woodpecker, horned lark, blue jay, crow, house sparrow, and Amer- ican goldfinch, were recorded in all years and zones in both winter and summer. In addition, chickadees, which were not iden- tified to species, were recorded in all zones in all census years. Species recorded in all years and zones in summer and in one or two, but not all three, zones in winter were the sparrow hawk, killdeer, red-headed woodpecker, robin, bluebird, loggerhead shrike, red- winged blackbird, grackle, cowbird, tow- hee, and field sparrow. In addition, mead- owlarks, which were not identified to spe- cies, were seen in all zones in summer and in a number of zones in winter. Species recorded in all years and zones in winter and in one or two, but not all three, zones in summer were the red-bellied woodpecker, tufted titmouse, white-breasted nuthatch, cardinal, and October, 1963 Graper & GRABER: song sparrow. In addition, the red-tailed hawk and hairy woodpecker were record- ed in a high percentage of years and zones in both summer and winter. Species recorded in all years and zones in summer only were the green heron, upland plover, yellow-billed cuckoo, chim- ney swift, eastern kingbird, crested fly- catcher, phoebe, wood pewee, barn swal- low, house wren, catbird, brown thrasher, red-eyed vireo, yellowthroat, orchard ori- ole, Baltimore oriole, indigo bunting, dick- cissel, and grasshopper sparrow. Species recorded in all years and zones in winter only were the junco and tree sparrow. Avifaunal Differences Between Censuses Of the 177 species of birds recorded in the two census periods, 104 appear on the lists for both periods, table 55. Four- teen species identified in 1906-1909 were not identified in 1956-1958. Species recorded in 1906-1909 but not in the later series of censuses were the lesser scaup, prairie chicken, sora, wood- cock, least flycatcher, yellow-bellied fly- catcher, Swainson’s thrush, Swainson’s warbler, magnolia warbler, chestnut-sided warbler, and palm warbler, all in sum- mer; and the golden eagle, bald eagle, and snow bunting, all in winter. Seven of these species were late spring migrants. The golden eagle, bald eagle, sora, wood- cock, Swainson’s warbler, and snow bunt- ing are either uncommon or have such spe- cialized habitat requirements that their appearance on the 1906-1909 list but not on the 1956-1958 list does not necessarily imply a population change. The prairie chicken was recorded for both summers in the early census and not at all in the later series. The population changes in this species have been studied by Yeatter (1943). Fifty-nine species of birds were identi- fied in 1956-1958 but not in 1906-1909. Included in this group were three intro- duced species, the ring-necked pheasant, gray partridge, and starling, which have become well established in Illinois since the time of the first surveys. Another in- troduced species, the rock dove, was not recorded in 1906-1909. This dove was so closely associated with human habitations Biro PopuLATIONS IN ILLINOIS 463 at the time of the early study that it was considered to be a domestic species and therefore was not censused. Native species not listed in 1906-1909 but listed in 1956-1958 (probably because between the two census periods they had increased in number or distribution in the state) were the common egret, little blue heron, black vulture, tree swallow, rough- need swallow, Bell’s vireo, prairie war- bler, western meidowlark, vellawehesded Sige eared: and Brewer’s Bleee earl The majority of species listed in 1956— 1958 but not in 1906-1909 were marsh or forest species. Their absence from the early list probably reflects only the fact that little acreage of marsh and forest was censused in 1906-1909. Species in this category were the horned grebe, least bit- tern, American bittern, mallard, black duck, blue-winged teal, wood duck, Coop- er’s hawk, Virginia rail, common galli- nule, American coot, common snipe, black tern, horned owl, saw-whet owl, whip- poor-will, pileated woodpecker, yellow- bellied sapsucker, long-billed marsh wren, hermit thrush, blue-gray gnatcatcher, ru- by-crowned kinglet, yellow-throated vireo, worm-eating warbler, cerulean warbler, yellow-throated warbler, pine warbler, ovenbird, Kentucky warbler, and hooded warbler. Other species that were not listed in 1906-1909 and that represent specialized habitat situations not widely covered in the early surveys were the blue goose, Canada goose, herring gull, and ring- billed gull. Certain species recorded in 1956-1958 but not in 1906-1909 occur either rarely or erratically in the state in summer or winter; hence, we would not necessarily expect to encounter them in both surveys, or in either. In this category were the short-eared owl, water pipit, Sprague’s pipit, cedar waxwing, northern shrike, rusty blackbird, blue grosbeak, Le Conte’s sparrow, Harris’ sparrow, white-crowned sparrow, and Smith’s longspur. Annotated List of Common Species Most of the species that make up the bulk of the bird population of Illinois are discussed in detail in the following pages. Some of the important forest spe- cies are not included because only limited 464 population data for the forest habitat were available from the 1907—1909 censuses. The population figures presented in this section were derived from density data for all habitats censused in 1906-1909 and 1956-1958. Not all of these popula- tion figures agree with data in habitat tables +-54. The data in the tables refer only to fields or blocks of habitat, whereas the figures in the species accounts include edge acreage as well as fields or blocks. For example, the sparrow hawk was not included in table 15 because it was not seen in fields of ungrazed grassland ; how- ever, ungrazed grassland is listed as a fa- vored habitat in the species account of the sparrow hawk because this species was found in an edge situation, that is, grass- land along roadsides. Turkey Vulture.—In summer, the turkey vulture was recorded in both the central and southern zones of Illinois, but, in winter, it was found only in the southern zone. The summer data on this species present a paradox, suggesting that after 1909 there was a slight increase in the central zone population and a marked decrease in the southern zone population. We estimate that in 1907-1909 there were less than 7,000 turkey vultures (breeding population) in the central zone, while in the southern zone the populations num- bered about 76,000 birds in 1907 and 43,- 000 in 1909. By 1957-1958, there were about 10,000 vultures in the central zone and only 15,000-16,000 in the southern zone. Range extension in a given species is often associated with population increase, but, in the turkey vulture, range extension appeared to be associated with thinning of the population. Figures for the early censuses should be considered minimal be- cause of the small acreage of forest (pri- mary nesting habitat) censused. According to the census data, vultures are likely to be encountered in almost any Illinois habi- tat. In 1907-1909, most vultures seen were in pastureland; this finding reflect- ed, in part, the large acreage of pasture- land covered. Winter data, as well as summer data, indicate a population decline in this spe- cies. In 1906-07, turkey vultures winter- ing in Illinois were concentrated in the southern zone, particularly in forest and Intinois NarurRAL History SurvEY BULLETIN Vol. 28, Art. 3 pastureland, where the estimated popula- tion was about 690,000 vultures—a pop- ulation far exceeding the entire state pop- ulation in summer. Though we saw turkey vultures in the winters of 1956-57 and 1957-58, none came within the census transects, and we judge that the winter population in those years was slightly less than the summer levels. Weather may have had a profound ef- fect on the winter populations of vultures, both in 1906-07 and in the later years. The winter of 1906-07 was unseasonably warm and wet, conditions that may have favored a high winter population. In both 1956-57 and 1957-58, the early part of the winter was unseasonably warm, but, in January, temperatures fell sharply, and the middle and late parts of winter were unusually cold. The cold may have pushed vultures to wintering grounds farther south. Despite the weather differences be- tween the winter of 1906-07 and the winters of 1956—57 and 1957-58, the dif- ference in vulture populations between the two census periods was so great that we feel the winter data corroborated the con- clusion, from summer data, that the tur- key vulture population in Illinois was re- duced greatly between 1909 and 1956. We can only speculate as to the cause of the reduction. The primary nesting habitat (forest) actually increased slightly in acreage after 1909, but a favored forag- ing habitat, pasture, was greatly reduced. The concurrent spreading and thinning of the population may be related to avail- ability of food, and this, in turn, may be related to man’s changing practices in livestock management. Red-Tailed Hawk.— The Forbes- Gross strip census method is not well suited for censusing hawks. While cen- sus takers are likely to see hawks, wary species such as the birds of prey are very unlikely to come within the census tran- sect lines. Our population figures for such species should be considered minimal; they are useful primarily for comparisons within this study. The red-tailed hawk was seen in a broad variety of habitats throughout the state. It was seen within the census tran- sects chiefly in woods and shrubby forest edge, probably because reduced visibility in these habitats permitted the census October, 1963 GrRaBpeR & GRABER: takers to come within sight of the birds, and also because red-tails were more prone to approach census takers in or near the nesting habitat than in other areas. Spe- cific population figures based on the cen- suses are questionable, but a few gen- eralizations may be derived from them. Despite the large acreage of forest nest- ing habitat in southern Illinois, the sum- mer population of the red-tail in the south- ern zone was decidedly low by comparison with populations in the central and north- ern zones. We estimate that the red-tail population in 1957 and 1958 numbered about 25,000 birds in each of the two zones farther north, but less than 15,000 in the southern zone. The 1958 statewide population was well below the 1957 level. Because relatively little forest was cen- sused in the summers of 1907 and 1909, comparisons of breeding populations of the red-tail in the two study periods are not warranted. Acreages of winter habi- tats censused in the two periods were nearly equal. Winter populations of the red-tailed hawk tended to be lower than summer populations in the northern and central zones of the state but higher than sum- mer populations in the southern zone. This pattern followed the generalized pic- ture of seasonal shift in the Illinois bird population, in which southern zone popu- lations increased from summer to winter while populations to the north decreased. The census data indicated that the winter -population of the red-tail in 1906-07 was much higher than that in either 1956—57 or 1957-58. We estimated that about 90,- 000 red-tails wintered in southern Illinois in 1906-07; the 1956-57 and 1957-58 winter populations in this zone were about 35,000 and 19,000, respectively. Christ- mas count data presented by Graber & Golden (1960:13) indicated that the 1906-07 population in central Illinois, at least, was above average. Sparrow Hawk.—The sparrow hawk was encountered throughout the state both summer and winter in all zones, but the census data indicated that there were some marked changes in the distribution pat- tern of this falcon between 1909 and 1956. In 1907-1909, the bulk of the state breed- ing population was in the southern zone, while, in 1957-58, most of the population Birp PoPULATIONS IN ILLINOIS 465 was in the central (particularly) and northern zones of the state. This species had a broad ecological dis- tribution, but ungrazed grasslands (mean density: 1.2 sparrow hawks per 100 acres in 1957-1958) and fallow fields (1.1 per 100 acres in 1907-1909) were by far the most favored foraging habitats in summer. Other important habitats (pastures, fields of mixed hay, and cornfields) had den- sities of not more than 0.5 sparrow hawk per 100 acres. ‘There was an apparent marked reduc- tion in the statewide population of the sparrow hawk between 1909 and 1957. The change in the southern zone was particularly marked. ‘The summer populations of the spar- row hawk in Illinois numbered about 90,- 000 birds in 1907 and 197,000 in 1909; in each of these years, about 70 per cent of the state population was in the south- ern zone. The difference in population between the two years was consistent from zone to zone; that is, in each zone the 1909 population was higher than the 1907 population. In 1957 and 1958, summer populations (maximum estimates) of the sparrow hawk in I[]linois were 33,000 and 78,000, respectively. In each of these years, about 65 per cent of the Illinois population was in the central zone, and the southern zone population was negligible. The drastic reduction in acreage of pas- ture in southern Illinois may have con- tributed to the decline of the population. At the time of the early censuses, pasture- land characteristically contained widely scattered, large trees that may have of- fered nesting cavities for the sparrow hawk. In recent years, farmers have be- come less tolerant of trees at the margins of their cultivated lands. Such trees are ideal nesting sites for the sparrow hawk, and their removal was detrimental to the bird. The increase in forest acreage in IIli- nois since 1907 would seem to have been more of a hindrance than a help to the sparrow hawk, which requires open forag- ing areas. Presumably, the sparrow hawk could compete with most other species of cavity-nesting birds, but, by sheer force of numbers, the introduced starling may have had a depressive effect on the sparrow hawk population. Winter data, as well as summer data, 466 indicated a decline in sparrow hawk num- bers between the two census periods. In winter of both census periods, the popula- tion was largely concentrated in the southern and central zones. Favorite for- aging habitats of the sparrow hawk in winter were cornfields (stubble or mechan- ically harvested), hayfields, small grain stubble, and pastures, all of which had densities of about 1 sparrow hawk per 100 acres in southern Illinois. In 1906-07, approximately 135,000 sparrow hawks were wintering in Illinois. About 81 per cent of the winter popula- tion was in the southern zone. In the winters of 1956-57 and 1957-58, popu- lations of the sparrow hawk were esti- mated to have numbered respectively 60,- 000 and 54,000 individuals; between 60 and 70 per cent of the state population was in the southern zone. Between 1907 and 1957, the summer (June) and win- ter (January) populations of the sparrow hawk showed about the same percentage of decline (60 per cent). The difference between the minimum 1907-1909 popula- tion (90,000) and the maximum 1957-— 1958 population (78,000) represented a decrease of about 13 per cent. Bobwhite.—Of the four galliform birds (prairie chicken, bobwhite, gray partridge, and ring-necked pheasant) re- corded in the census strips, the native bob- white was the most widely distributed and abundant. The strip census method, in- tended primarily for censusing songbirds, is a poor method for censusing game birds. Quantitative data on bobwhite popula- tions were highly variable in both census periods, but populations were consistently highest in the southern zone, diminishing progressively to the north. For example, in 1909, summer population densities for the quail in pastureland were about 6.8 birds per 100 acres in the southern zone, 5.2 in the central, and 1.0 in the northern. Accompanying the progressive north to south increase in bobwhite numbers was a parallel increase in ecological distribution; in the southern zone, bobwhites were counted in virtually every type of habitat but urban areas. Habitat preference of the bobwhite appeared to have been similar in 1907-1909 and 1957-1958. The most consistently favored summer habitats were shrubbery of all types, orchards, hayfields, Ittrnois NaTuRAL History SurRvVEY BULLETIN Vol. 28, Art. 3 ungrazed grasslands, and pasture. Densi- ties of bobwhite populations in various summer habitats in southern Illinois in 1957-1958 were 137.0 birds per 100 acres in hedgerows, 45.0 in edge shrubs, 12.0 in mixed hay (3.3 in 1907-1909), 6.4 in or- chards (8.8 in 1907-1909), 5.6 in un- grazed grassland (4.8 in 1907-1909), 5.0 in pastures (5.1 in 1907-1909), 4.6 in shrub-grown areas (8.0 in 1907-1909), 3.5 in red clover (7.7 in 1907-1909), 2.2 in fallow fields (2.5 in 1907-1909), 1.5 in wheat (in 1907-1909, 4.2 in wheat and 5.5 in oats), 1.2 in forest, and 0.8 in corn (0.4 in 1907-1909). There were no con- sistent differences in density between 1907-1909 and 1957-1958; densities in grassland habitats in the two study periods were roughly comparable. From census data and crop acreage sta- tistics, we estimated that the June popu- lation of the bobwhite in the southern zone was about 446,000 birds in 1907 and 643,000 in 1909. A difference in popula- tion density in these two years was ex- pressed in almost every habitat in both the southern and central zones, and the differ- ence was even more striking in the central than in the southern zone (central zone estimates: 53,000 birds in 1907; 169,000 in 1909). For the northern zone, the 1909 estimate was about 30,000 birds (no northern zone data are available for 1907). In terms of numbers and geographic distribution, the summer quail population appears to have changed little since the first study period. The statewide popula- tion was at least 500,000 birds in 1907 (1907 data lacking for northern zone) and 842,000 in 1909; in these years, about 80 per cent of the state population was concentrated in the southern zone and only about 4 per cent was in the northern. In 1957, the estimated population was about 599,000 bobwhites, 80 per cent of — which were in the southern zone and only 6 per cent in the northern zone. Annual fluctuations were notable at the time of the second study period, and the 1958 state population was up to at least 662,000 birds. The population increase in the state between 1957 and 1958, like that in the central and southern zones between 1907 and 1909, was consistent from zone to zone and from habitat to habitat. pat abihe Satan sii i SE rahe Pat et October, 1963 Grazer & GRABER: While the numbers and geographic dis- tribution of the bobwhite were about the same in the two study periods, the species has recently faced some noteworthy eco- logical changes. Grassland pasture, prob- ably the most important single summer habitat in 1907-1909, had decreased by 1957 to less than one-third of its former area. With this change, hayfields, which increased in acreage, probably became the primary summer habitat for the bobwhite. Our population estimates, for both the early and recent census years, probably slighted the marginal or edge habitats such as roadsides and hedgerows. Some of the unaccounted acreage for the state (about 2,000,000 acres not accounted for in 1907— 1909 and 3,000,000 in 1957-1958) may represent such high-density quail habitats. The quail populations were much larger in winter than in early summer (all census years) and shifted more to woody habi- tats, fallow fields, and hayfields. Small grain fields (stubble) were important winter habitats; pastureland, even in 1906-1907, was less important in winter than in summer. In 1906-07, when corn was hand picked, bobwhites frequented this cornstalk habitat, particularly in southern Illinois; changes in harvesting methods virtually eliminated this special habitat. The January, 1907, population of quail in the southern zone was estimated to be about 1,892,000 birds. The central zone had about 124,000 bobwhites and the northern zone 66,000, making a total of about 2,082,000 in the state. In the win- ter of 1956-57, the state quail population numbered about 1,773,000 birds; the number was down to 599,000 by June, 1957, up to 2,235,000 in January, 1958, and down to 662,000 in June, 1958. The amount of fluctuation was about the same in the two study periods. As quail num- bers are probably at a peak in late sum- mer and minimal in spring, our figures do not represent maximum annual fluctua- tions. The reader should bear in mind that, for the quail, the strip census method may be more effective in winter than in summer; this difference would tend, of course, to accentuate the difference be- tween our winter and summer estimates of population. The figures imply that the mortality rate of quail between January Birp PoPpuULATIONS IN ILLINOIS 467 and June is high (60 and 68 per cent, re- spectively, in 1957 and 1958) and that good production of young in one nesting season does not necessarily increase the nesting population in the following year. There are, apparently, differences in rates of production and mortality between areas with high and areas with low population density. In the early census period, the ratio between winter (1906-07) and sum- mer (1907) populations was about 4:1 in southern Illinois and 3:1 in central Illi- nois; in the later census period, the ratio between winter (1957-58) and summer (1958) populations was 3:1 in southern Illinois and 2:1 in central Illinois. In all vears, both production and mortality were relatively higher in the southern zone (high-density area) than in the central zone (low-density area). These charac- teristics tend to make the total Illinois quail population unchanging from year to year and, coupled with the subtle nature of the habitat changes, help to account for similarities between the 1906-1907 and the 1956-1958 figures. Killdeer.—Only five species of shore- birds, killdeer, American woodcock, com- mon snipe, upland plover, and spotted sandpiper, were encountered in the cen- suses. Of these, the killdeer and upland plover were common enough to warrant special discussion. In summer, the killdeer was counted in all zones as well as all years but, in win- ter, it was detected only in the southern zone and only in very small numbers. Though the killdeer occurred throughout the state in summer, the density of killdeer populations varied from zone to zone in an interesting and unexplained ecological pattern. Cornfields provided a relatively high-density habitat in the southern zone (4.3 birds per 100 acres in 1957-1958; 4.6 in 1907-1909), but a low-density hab- itat in the central zone (0.2 in 1957- 1958; 0.3 in 1907-1909). Conversely, pastureland had higher killdeer popula- tions in the central zone (1.2 birds per 100 acres in 1957-1958; 1.8 in 1907- 1909) than in the southern zone (0.8 in 1957-1958; 0.7 in 1907-1909). In this ecological variation, northern zone popu- lations tended to follow central zone pop- ulations. The killdeer is one of the species of 468 birds that would seem to be favored by row-crop agriculture. It favors habitats with large amounts of bare ground, and population densities for this species tend to fall as vegetative cover increases in a habi- tat. Densities of killdeer populations in various habitats in southern Illinois in 1957-1958 were 10.6 birds per 100 acres in marshland (dry margins), 10.0 in plowed ground (2.2 in 1907-1909), 8.2 in alfalfa, 4.3 in corn (4.6 in 1907-1909), 4.1 in soybeans (7.7 in beans in 1907- 1909), 0.8 in pasture (0.7 in 1907-1909), 0.4 in fallow fields (0.3 in 1907-1909). In 1957-1958, mixed hay and red clover had negligible populations of killdeers in the southern zone; in the central zone, red clover had 2.2 birds per 100 acres (2.1 in 1907-1909), and, in the northern zone, mixed hay had 2.2 birds per 100 acres. Generally in hayfields, the killdeer favors spots where the vegetation is thin and low; thus, the population in some hay- fields may be high. The best of the habi- tats, as shown by high population, were the marshes (principally the dry margins) in northern Illinois, where the density was 11.5 birds per 100 acres. Sand prairie in the northern zone had 2.4 killdeers per 100 acres. All of the above-mentioned habitats were probably both nesting and foraging sites for killdeers. There is no indication that habitat pref- erences of the killdeer changed between 1909 and 1957. Population densities for given habitats were similar in the two pe- riods. The census data indicated a north- ward trend in the state killdeer population between 1909 and 1957. In many habi- tats, population densities in the northern zone increased during this period. In pas- tures of this zone, for example, there were 1.0 killdeer per 100 acres in 1909 and 2.9 killdeers per 100 acres in 1957-1958; in cornfields, 0.0 in 1909 and 2.6 in 1957- 1958; in mixed hay, 0.0 in 1909 and 2.2 in 1957-1958. In June, 1909, the south- ern zone of IIlinois had an estimated pop- ulation of about 339,000 killdeers (83 per cent of the state population) ; the popula- tion diminished rapidly and progressively to the north, and the northern zone had only about 14,000 killdeers (less than 4 per cent of the state total). In 1957 and 1958, populations in the northern zone were, respectively, 119,000 (36 per cent of Ittinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 — state total) and 125,000 (24 per cent of — state total). By our estimates, June populations of — the killdeer in the state numbered about 406,000 birds in 1909, 326,000 in 1957, and 524,000 in 1958. Year-to-year vari- — ation in the breeding population, obvi- ously, was high. Because the killdeer nests on the ground in a minimum of cover, it — may be particularly influenced by weather during the nesting season (April-June). — By winter of each year, migration has — carried most of the killdeer population south of Illinois. A few killdeers may be found even in the northern zone in winter, — but populations north of the southern zone — are usually negligible. With the change in — season, there is also a habitat change, and, in both the early and recent winter cen- — suses, clover and alfalfa fields, almost to the ex- clusion of other habitats. and 1956-57 winter populations of the — killdeer were comparable (about 157,000 birds each winter). By comparison, the — 1957-58 population was very low (about 11,000 birds). 1906-07 and 1956-57. Southern Illinois — experienced unusual cold in 1957-58, — which probably pushed the killdeer popu- lation farther south than usual. i Upland Plover.—The upland plover — was recorded throughout the state in sum- _ mer; highest frequencies were in the cen- _ tral and northern zones. 4 This plover was found in a variety of open-field habitats—pasture, hayfields, fal- — low fields, small grain, corn, and soybeans; the greatest densities were in pastureland and hayfields (especially red clover). F Densities of upland plover populations were, in certain habitats, roughly com- — parable in the northern and central zones ~ and conspicuously lower in the southern. — Densities in Illinois pastureland in 1907— — 1909 were 3.1 birds per 100 acres in the — northern zone, 2.0 in the central, and 0.3 — in the southern. Population densities of — the upland plover in various habitats of — the northern and central zones (com- — bined) in 1957-1958 and 1907-1909 were 7.5 birds per 100 acres in red clover fields — (22.5 in 1907-1909), 2.2 in mixed hay © and alfalfa (1.3 in 1907-1909), 0.7 in the killdeer was found to favor — The 1906-07 — The winter census of 1957-58 was conducted about 3 weeks later in the year than the censuses of October, 1963 Graper & GRABER: Birp PopuLATIONS IN ILLINOIS 469 pastures (2.4 in 1907-1909), 0.8 in small southern Illinois, 12.2 in the central zone, grain fields (0.1 in 1907-1909), and 0.5 in corn (0.5 in 1907-1909). Both pasture and hayfields were re- corded as nesting habitats of the upland plover; the other habitats listed proba- bly represented only foraging areas. The ecology of the species seems to be chang- ing. The density data suggest that pasture (a declining habitat) is becoming less im- portant to the plover, while mixed hay and alfalfa are becoming more important. In the southern zone, alfalfa was the most important plover habitat in the second census period. While the range of the upland plover in the state did not change between 1909 and 1957, the distribution of the popula- tion changed considerably. In 1907-1909, about half (140,000 birds) of the state population (283,000 birds) was found in the northern zone, and the remainder was fairly evenly divided between the central and southern zones. By 1957-1958, the state population (208,000 in 1957; 177,- 000 in 1958) had declined; in both years, most (60-80 per cent) of the population was in the central zone, and less than 15,- 000 birds of this species were in the south- ern zone. The decline of the state population and the shift of the population toward central Illinois may be related to habitat changes. The great loss in pastureland acreage was probably a primary factor in the decline. The density data suggest that the quality of pastures (as plover habitat), as well as the acreage, declined. The relative in- crease of the plover in the central zone re- flects, to some extent, the increase of red clover acreage in this zone after 1909. Mourning Dove.—In all census years, the mourning dove occurred throughout the state in both summer and winter; the winter populations tended to be concen- trated in the southern zone. No species of bird in the state had a broader ecological distribution than the mourning dove, which was found nesting and foraging in virtually all terrestrial, shrub, and arboreal habitats. Dove popu- lations were highly variable in density from habitat to habitat and from zone to zone. The 1957-1958 densities of sum- mer dove populations in shrub-grown areas were 11.1 birds per 100 acres in and 15.5 in the northern. By contrast, densities in soybean fields were 6.6 per 100 acres in the southern zone, 4.3 in the cen- tral zone, and 3.6 in the northern. Rated on the basis of population den- sity (all census years considered), habitats most favored by the mourning dove in summer were marginal or edge shrubbery, hedgerows, sweet clover fields, prairie or ungrazed grasslands, orchards, marshes, urban residential areas, and fallow fields. Average densities of mourning dove populations in various summer habitats in the state in 1957-1958 were 142.5 birds per 100 acres in edge shrubs, 97.6 in hedgerows, 39.5 in sweet clover, 38.0 in ungrazed grassland (10.7 in 1907-1909), 32.9 in orchards (46.5 in 1907-1909), 31.6 in fallow fields (10.6 in 1907-1909), 29.7 in marshes, 28.6 in urban and rural residential areas (1.8 in 1907-1909), 15.5 in red clover (9.3 in 1907-1909), 12.0 in shrub-grown areas (17.3 in 1907-1909), 7.5 in plowed fields (14.1 in 1907-1909), 6.0 in wheat fields (13.8 in 1907-1909), 4.8 in alfalfa, 4.6 in mixed hay (6.2 in 1907-1909), 4.5 in soybean fields, 3.6 in forest (10.2 in 1907-1909), 2.6 in pas- tures (5.4 in 1907-1909), 2.6 in corn- fields (4.4 in 1907-1909), and 1.3 in oat fields (2.9 in 1907-1909). A small acre- age of savanna-type habitat had about 11 doves per 100 acres. Harvesting of crops greatly alters the ecological distribution of the dove, for this species tends to concentrate in fields where the crops have been cut. For example, in 1907-1909 in southern Illinois, there were 74 doves per 100 acres in cut wheat fields and only 17 per 100 acres in uncut wheat. Similarly, in 1957-1958 in the northern zone, there were 11 doves per 100 acres in mowed hayfields and 3.6 in uncut hay- fields. Certain apparent habitat preferences of the mourning dove in summer are note- worthy. The high density of birds at marshes may well represent concentrations of doves seeking water. The fallow-field habitat was genuinely favored by the dove, and our experience showed this was the open-field type that was most used for nesting. Clover fields seem to have been much favored over mixed hay and alfalfa fields. Most of the doves found in the 470 hayfields, particularly those in harvested hayfields, were probably foraging. Wheat, generally a very poor bird habitat, had relatively high populations of doves. Han- son & Kossack (1957:178; 1963:92) have pointed out the importance of wheat in the mourning dove diet. In 1907-1909, rye was a much-favored habitat in south- ern Illinois—probably even more than wheat—but the sample was too small to give a valid density figure. Oat fields were the poorest of the dove habitats in all zones of the state. Open space appears to be an important characteristic of all of the dove habitats with high population density ; the difference between dove popu- lations in urban areas (high density) and those in forests (low density) may in part reflect this characteristic. The density figures presented above rep- resent mostly, but not solely, adult popu- lations. While we did not include iden- tifiable juveniles in the calculations, some well-grown birds of the year were surely counted as adults. The figures include both nesting and foraging doves in each habitat. In the censuses of 1907-1909 and 1957-1958, several ground nests of the mourning dove were found in open- field habitats, but we have no way of knowing what per cent of the population found in open fields represented nesting birds. We judge that only a few habitats (shrub, orchard, urban area, and fallow field) have high nesting densities of the mourning dove, and these habitats repre- sent a small per cent of the land acreage of the state. In all but four of the summer habitats (fallow field, ungrazed grassland, red clover, and urban and rural residential areas), densities averaged higher in 1907- 1909 than in 1957-1958. There is evi- dence of a northward shift in the dove population between 1909 and 1957. In 1907-1909, population densities of the mourning dove in several habitats (pas- ture, prairie, orchard, corn, and plowed fields) tended to be highest in the south- ern zone and lowest in the northern; in 1957-1958, dove populations in some of these habitats showed highest densities in the northern zone, lowest in the southern. For example, in pastureland in 1907— 1909 there were about 2.1 doves per 100 acres in the northern zone, 5.0 in the cen- Intuinois NarurAL History SuRVEY BULLETIN Vol. 28, Art. 3 tral, and 6.3 in the southern, but in 1957- 1958 densities were 2.9 in the northern zone, 2.9 in the central, and 1.7 in the southern. Of all the habitats, only or- chard was consistent in having highest densities in the southern zone in all years. Some of the patterns of summer distri- bution seemed contradictory. Why should orchards have had highest concentrations of dove populations in the southern zone, while shrub and urban residential areas had highest concentrations in the northern zone? Some distribution patterns may have been related to habitat availability. For instance, shrub acreage was low in the northern zone, and doves may have tended to pack the available area of this excellent nesting habitat. The limited acreage of shrub areas in northern Illinois may also have accounted for the high densities of dove populations in the northern urban areas. Within a given habitat or a particular geographic area, mourning dove popula- tions may fluctuate greatly from year to year. Hanson & Kossack (1963:115-7) reported great year-to-year fluctuations in the habitats and area they studied. In the statewide and zonewide populations of the periods reported here, we found that popu- lation fluctuations in the mourning dove were remarkably small in comparison with population fluctuations in many other spe- cies. Our estimates of the statewide mourn- ing dove populations were as follows: 2,438,000 in 1909 (about 2,500,000 in 1907, as estimated from central and south- ern zone data), 2,000,000 in 1957, and 2,000,000 in 1958. Such small fluctua- tions were, perhaps, to be expected in a broadly distributed species, which may suffer losses in one zone or habitat and balance them by gains in another zone or — another habitat. Because dove popula- tions varied little from one census year to the next, we believe that there was an actual decline in the state population be- tween the two census periods amounting to about 19 per cent of the 1907-1909 level. Most of the loss appears to have been in the southern zone _ population, dropped from about 1,500,000 birds in 1907-1909 to about 1,100,000 in 1957— 1958. The 1957-1958 dove populations — in the northern zone (about 400,000 © which — October, 1963 Graper & GRABER: birds) and the central zone (about 500,- 000 birds) were almost the same as the 1907-1909 populations in these zones. Winter populations of the mourning dove in the northern and central zones were sparse in all census years; the south- ern zone had more than 90 per cent of the state population in winter. Some noteworthy changes took place between 1906-07 and 1956—57 in the winter dove population and its ecology. In 1906-07, most of the wintering doves of the state were found in one habitat, cornstalk (picked corn) fields, where pop- ulation densities were 0.7 bird per 100 acres in the northern and central zones and 35.6 per 100 acres in the southern zone. Changing agricultural methods vir- tually eliminated this preferred habitat. The agricultural replacement for cornstalk habitat was the mechanically picked corn- field, which had average densities, in 1956-57 and 1957-58, of 0.3, 0.5, and 3.7 doves per 100 acres in the northern. cen- tral, and southern zones, respectively. Population densities in other winter habi- tats in the southern zone (1956-57 and 1957-58 average) were 103.8 doves per 100 acres in shrubs, 23.1 in bean stubble, 9.0 in ungrazed grass, 8.0 in forest, 1.9 in fallow fields, 1.3 in hay, 1.0 in wheat, and 0.8 in small grain stubble. The most con- sistently used habitats were forest and cornfields in the northern and central zones and shrub-grown areas and corn- fields in the southern zone. The mourning dove apparently win- tered farther north in much higher num- bers in 1956-1958 than in 1906-07. In 1906-07, a notably mild winter, the state dove population (all habitats) numbered about 350,000 birds; the lower popula- tion of the two later censuses (1957-58) was about 1,200,000 birds, despite the fact that weather conditions were more adverse to wintering doves in 1957-58 than in 1906-07. In both 1906-07 and 1957-58, dove populations in the northern and cen- tral zones (combined) numbered less than than 50,000 birds, a negligible part of the state total. The increase noted above was primarily in the southern zone of the state. Year-to-vear variation in the winter dove population was high, and the dif- ference between the 1956—57 and 1957-58 populations warrants discussion. State Birp PopuULATIONS IN ILLINOIS 471 populations in 1956-57 and 1957-58 num- bered about 2,000,000 and 1,200,000 birds, respectively. A factor that may have had some bearing on the reduced number in 1957-58 was the unusual and pro- longed cold during the fall dove migration season (1957), which may have effected a more extensive evacuation of doves from the state. In addition, our census schedule was late in 1957-58 (running into Febru- ary), and extreme cold in January and February may have pushed doves farther south. Censuses conducted in late Decem- ber, 1956, and early January, 1957, when mild winter conditions prevailed, showed a dove population for the northern and central zones of about 130,000 birds. By contrast, the populations in these zones, following prolonged cold in January and early February, 1958, were negligible. These data, coupled with the great in- crease in the population of the southern zone between the winters of 1906-07 and 1956-57, indicate that the northern edge of dependable winter range for the mourn- ing dove in Illinois is south of latitude +0 degrees. ‘The increase that occurred in the win- ter dove population of the southern zone between 1906-07 and 1956-57 is puz- zling, particularly in view of the apparent decline in the breeding population. The change follows a pattern of northward range extension which we can observe in many species of birds. Regardless of the underlying cause of the range extension, it is conceivable that the populations in- volved may tend to concentrate, that is, increase where some climatic or other bar- rier delimits the range extension. Such a mechanism may be involved in the increase in the winter dove population of Illinois. Because nesting populations of the mourning dove have low densities in open- field habitats, intensive cultivation, espe- cially when accompanied by removal of such high-density dove habitats as edge shrubs, hedgerows, and orchards, is detri- mental to the dove. Activities of the ex- panding human population in urban areas may compensate to some extent for the loss of nesting sites in rural areas, because plantings in residential urban areas have large dove populations. The mourning dove may, in fact, be adapting to this ex- panding habitat, as the early censuses 472 Intinoris NaturRAL History SURVEY BULLETIN showed few doves in urban residential areas. Cuckoos.—In all census years com- bined, the two cuckoos were counted in a ratio of about 14 yellow-bills to 1 black- bill. The yellow-billed cuckoo occurred throughout the state in summer of all cen- sus years; it was most abundant in the southern zone, least abundant in the northern. In most habitats, population densities were highest in the southern zone. In edge shrubbery in 1957-1958, there were 10.0 birds per 100 acres in the south- ern zone and 8.4 in the northern zone. Densities of yellow-billed cuckoo popu- lations in various summer habitats in the southern zone in 1957-1958 were 45.7 birds per 100 acres in hedgerows, 10.0 in edge shrubbery, 3.9 in orchards (6.6 in 1907-1909), 1.6 in shrub-grown areas (12.0 in 1907-1909), 0.8 in pastures (0.2 in 1907-1909), 0.6 in forest (3.3 in 1907— 1909). In 1907-1909 only, the yellow- billed cuckoo was found in residential habitat (6.0 birds per 100 acres), wheat fields (0.7), and mixed hay (0.5). The density data suggest that the cuckoo population declined between 1909 and 1957. Our estimates of the state pop- ulations in different years were 167,000 birds in 1907, 383,000 in 1909, 92,000 in 1957, and 59,000 in 1958. The estimates indicate a notable population decrease. Habitat changes that eliminated some of the best cuckoo nesting areas in the state undoubtedly had some effect on the cuckoo population; among these changes were the decrease in the acreage of orchards by 1958 to about one-tenth of the 1909 acre- age and the destruction of many hedge- rows and roadside shrubs along field boundaries. An increase in forest-edge habitat in southern Illinois compensated but little, for this had become a low-den- sity habitat for cuckoos. Cuckoos were found in residential areas in 1907-1909 but not in 1957-1958. The difference may reflect some change in the nature of plantings near human habitations. Chimney Swift.—In all census years, the chimney swift was found in summer throughout the state. Before white settlement, chimney swifts probably placed their nests in hollow trees. They may still use such nesting sites, but Vol. 28, Art. 3 most of the population nests in man-made chimneys. This very specialized nesting habitat and the special feeding method of the chimney swift complicate discussion of populations of this species. In urban resi- dential areas in 1958, we counted 24.4 swifts per 100 acres in the southern zone, 26.8 in the central zone, but only 14.4 in the northern zone. On the other hand, population densities of the swift foraging in nonurban areas tended to be highest in the northern and central zones. The ur- ban densities were lowest where the avail- ability of nesting sites was highest. Most of the state’s urban acreage is in the north- ern zone (71 per cent in northern zone, 13 per cent in central zone, and 16 per cent in southern zone). Because of its great mobility, the swift was encountered in every habitat censused. Populations were not distributed over the various habitats in proportion to the acre- age distribution of the habitats. For ex- ample, cornfields comprised the largest (in terms of acreage) single habitat in the state, and the largest habitat sampled, but only about 11 per cent of the swifts counted were over cornfields; about 35 per cent were over hayfields, which had about half the acreage of cornfields. In all census years, hayfields (various types), pasture, and fallow fields were the favored foraging habitats of the swift. Population densities of foraging swifts over hayfields of all types (an expanding habitat) were about the same (average density 3.4 birds per 100 acres) in 1957-1958 as in 1907-1909, but in pas- tureland (a diminishing habitat) swift numbers showed an increase between 1907-1909 (1.2 per 100 acres) and 1957— 1958 (4.6 per 100 acres). ‘These obser- vations suggest that the swift has been consistent in habitat preferences through — the years. Populations over alfalfa were comparable to those over mixed hay. Red clover and sweet clover fields were par- ticularly favored (average density: 7.2 swifts per 100 acres); total clover acre- age increased between 1909 and 1957. In other habitats, densities (all census years combined) were 1.4 swifts per 100 acres — in fallow fields, 1.1 in small grain, and — 0.6 in corn. We do not imply by these — observations that the swift consciously chooses particular foraging habitats. The October, 1963 GraBer & GRABER: distribution of foraging swifts probably reflects distribution of insect concentra- tions, which vary from habitat to habitat. It is difficult to estimate population change, if any, in the chimney swift be- tween 1909 and 1957. Population densi- ties of this species in urban areas, perhaps the best guide, were 6.0 birds per 100 acres in the southern zone in 1909 and 24.4 in the same zone in 1958. Ecological changes since 1909 appear to be highly favorable to the chimney swift. With in- creased nesting habitat arising through urbanization, and an increase in favored foraging habitats, the swift population may increase along with the human popu- lation. Yellow-Shafted Flicker. — Of the seven species of woodpeckers (yellow- shafted flicker; pileated, red-bellied, red- headed, hairy, and downy woodpeckers; and yellow-bellied sapsucker) found with- in the census strips (all years included), the flicker was the most abundant. It was counted in all zones and years, both sum- mer and winter. The yellow-shafted flicker was found in a great variety of summer habitats, and in all of them population densities were consistently (all census years) highest in the northern zone. Densities were slightly lower in the central zone than in the northern and fell off sharply in the southern. For example, in 1909, pasture- land had 16.6 flickers per 100 acres in the northern zone, 14.9 in the central zone, but only 4.3 in the southern. Favored summer habitats of the flicker were hedgerows, savanna-type areas, edge shrubbery, residential areas, and forest. Densities of flicker populations in various summer habitats in northern Illinois in 1957-1958 were 31.4 birds per 100 acres in hedgerows, 21.6 in savanna-type areas, 8.4 in edge shrubbery, 5.6 in residential areas (27.8 in 1909), 5.6 in forest, 3.0 in shrub-grown areas, 2.9 in pastures (16.6 in 1909), 2.2 in mixed hay (6.8 in 1909), 2.1 in fallow fields (20.6 in 1909), 1.2 in oat fields (1.2 in 1909), 1.0 in ungrazed grassland (6.8 in 1909), and 0.8 in corn- fields (2.8 in 1909). (No surveys were made in northern Illinois in 1907.) Har- vested haytields and clover fields, which often have high bird populations, were apparently not attractive to flickers. In all Birp PopuULATIONS IN ILLINOIS 473 habitats for which we have comparative data over the entire state, population den- sities of the flicker were much lower in 1957-1958 than in 1907-1909. As the density data imply, the state flicker population declined greatly be- tween the two study periods, from about 2,279,000 birds in 1909 to 300,000 in 1957 and 225,000 in 1958. Perhaps 1909 was a bumper year for flickers. The popu- lation was lower in 1907 than in 1909; yet the central and southern zones in 1907 (no census in the northern zone that vear) had about 727,000 flickers, more than twice the 1957 or the 1958 population for the entire state. Causes for the decline in flicker num- bers can only be surmised. WHabitat changes probably had some effect. The flicker is not strictly a forest bird. Open fields, particularly grassland, and scattered trees for nesting sites are probably the essential habitat requirements. While IIli- nois contained more forest in 1957-1958 than in 1907-1909, savanna-type situations in the state probably were greatly reduced ; tree removal from field edges and tillable land has recently been common practice in Illinois. Reduction of pasture acreage eliminated some nesting sites (scattered trees), as well as good foraging habitat. The introduction of the starling may have played a very important role in re- ducing the flicker population. Competi- tion among certain species for nest cavities is keen, and starlings have proved their ability to compete. Of all the Illinois picids, the flicker has been most closely as- sociated with man and is therefore proba- bly most in competition with the intro- duced bird. In the summers of 1957 and 1958, flicker populations varied from place to place in urban areas inversely with the starling populations. The change in the flicker population between 1909 and 1957 accentuated its north-south cline. The northern zone of Illinois had about 841,- 000 birds in 1909 and 186,000 in 1957; the southern zone had 445,000 in 1909 and less than 15,000 in 1957. In winter, most of the Illinois flicker population was found in the southern zone. In contrast to the summer popula- tion densities, winter densities were not consistently lower in 1956-1958 than in 1906-07. 474 In 1906-07, the picked cornfields with stalks still standing comprised the favorite winter habitat of the flicker, as well as many other species, in southern Illinois; no other habitat boasted such a high den- sity (7.7 flickers per 100 acres in contrast to 1.7 for corn stubble only). Other fa- vored habitats were shrub areas, ungrazed grassland, forest, and pasture. Flicker population densities for these and other winter habitats in the southern zone for 1956-1958 were 6.0 flickers per 100 acres in hayfields (1.0 for 1906-07), 4.6 in shrub-grown areas, 3.8 in forest (2.5 for 1906-07), 2.2 in ungrazed grassland (6.6 for 1906-07), 2.0 in pasture (2.9 for 1906-07), and 2.0 in mechanically picked cornfields (for 1906-07, 1.7 in stubble and 7.7 in hand-picked fields). The corn- stalk habitat, by its attractiveness and almost unlimited availability, may have been partly responsible for low densities of the flicker in other habitats in 1906-07. Winter wheat, an ample habitat in south- ern Illinois, apparently was not used by the flicker, nor were fields of small grain stubble to any considerable degree. In January, 1907, there were about 544,000 flickers wintering in the state (75 per cent in the southern zone). In Janu- ary, 1957, the state flicker population numbered about 202,000 birds (85 per cent in the southern zone). As in popu- lations of some other species, flicker popu- lations apparently shifted southward in late winter, for in February, 1958, about 394,000 birds (96 per cent of the state population) were in the southern zone and less than 20,000 in the rest of the state. Red-Bellied Woodpecker.—In 1907-1909, the breeding population of the red-bellied woodpecker in Illinois was virtually restricted to the southern zone, but, in 1956-1958, this species was found in all zones of the state. The primary habitat for the red-bellied woodpecker was forest, in which summer populations were remarkably constant at about 5 birds per 100 acres in the south- ern zone in both the early and later cen- sus years. By 1957-1958, the central zone forests also had attained densities of about 5 birds per 100 acres, but the nesting population in the northern zone was still very sparse. Because population densities of the red-belly appeared to level off at 5 Ittinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 birds per 100 acres in both the southern and central zones, we believe that this fig- ure represents a saturation level for the breeding population in this species. Other habitats frequented by the red- belly in summer were shrub areas and grassland, especially pasture, which were probably foraging areas (usual densities: about 2 birds per 100 acres in each of these habitats). In the winters of 1956-57 and 1957— 58, the red-bellied woodpecker populations in forest increased over the summer levels in all zones of the state. From the sum- mer density of 5 birds per 100 acres, the forest population increased by winter to 9 birds per 100 acres in the southern zone and 7 per 100 acres in the central zone. Because the red-bellied woodpecker is not a strongly migratory species, much of the winter increment probably represented local production. Both the geographical distribution (extension of the range northward ) and the ecological distribution of the red-bellied woodpecker were greater in winter than in summer. Evidence of a northward extension of the population in winter was the fact that the forest popula- tion in the northern zone increased from a very sparse population in summer to about 3 birds per 100 acres in winter. Ecological extension was evident in win- ter when the red-belly was seen in shrub areas, fallow fields, pastures, and even row crops. Winter densities in nonforest habi- tats were usually 1 to 2 birds per 100 acres. The ecological extension may have represented both a wandering juvenile population and a seasonal change in for- aging habits by the total population. We estimate that the breeding popu- lation numbered about 103,000 in 1907 and 119,000 in 1909, all in the southern zone. By 1957-1958, the number of red- bellies in the state had greatly increased (to at least 198,000 in 1957 and 153,000 in 1958), with most of the population in the southern and central zones. The pop- ulation will probably continue to increase in the northern zone. Because the red- bellied woodpecker is a forest species (not associated with man), it is less in com- petition with the starling than is the flicker. Red-Headed Woodpecker.—In all census years, the red-headed woodpecker October, 1963 Graper & GRABER: was encountered throughout the state in summer, but only in the southern and cen- tral zones in winter. In 1907-1909, sum- mer populations of the red-head were fairly uniformly distributed in the state, but, in 1957-1958, the southern zone had a negligible part of the state population. Populations of this species are notoriously variable from year to vear, but, even after considering this annual variation, we believe that the red-headed woodpecker population was much higher in 1907-1909 than in the later census years. Like the flicker, the red-headed wood- pecker appeared to prefer a savanna-like situation in summer; it was found often in open fields. Favored summer habitats, in addition to savanna-type, were shrub- grown areas and forest. The red-headed woodpecker was found in virtually every habitat censused in 1907—1909, but in only a few habitats in 1957-1958. Densities of red-headed woodpecker populations in various habitats in the state in 1907-1909 were 22.1 birds per 100 acres in shrub- grown areas (1.4 in 1957-1958), 12.8 in forest (2.3 in 1957-1958), 5.8 in or- chards, 3.8 in fallow fields, 3.7 in red clover (0.7 in 1957-1958), 3.6 in pas- tures (0.2 in 1957-1958), 3.5 in ungrazed grassland (2.1 in 1957-1958), 2.7 in plowed fields, 1.8 in residential habitat (0.6 in 1957-1958), 1.5 in wheat, 1.2 in mixed hay, 1.1 in corn (0.1 in 1957- 1958), and 0.4 in oats. Savanna-like areas censused in 1957-1958 had 16.0 red- headed woodpeckers per 100 acres. The summer populations of the red- headed woodpecker in 1957-1958 were but a small fraction of those in 1907- 1909. We estimated that there were about 1,270,000 red-headed woodpeckers (breed- ing adults) in the state in June, 1909. but only 115,000 in 1957 and 134,000 in 1958. The 1907 population may have been under 1 million (no northern zone census in 1907), but it was still at least seven times as great as the 1957-1958 populations. The red-head and the flicker had a similar pattern of gross population reduction in the state, a reduction that was especially noticeable in the southern zone. These two species have certain habi- tat preferences in common; in summer, they, more than other species of wood- peckers, seek nonforest habitats. The in- Bird POPULATIONS IN ILLINOIS 475 troduction of the starling and some sub- tle, though important, habitat changes dis- cussed in the section on the flicker have probably had harmful effects. The red-headed woodpecker is migra- tory and in winter it usually vacates the northern parts of its breeding range. In winter, forest becomes the primary habitat almost to the exclusion of other habitat types. The red-headed woodpecker in IIli- nois wintered farther north in 1956- 1958 than in 1906-07. This northward extension may represent a trend, though the winter distribution of red-heads varies greatly from time to time and de- pends on availability of acorns and on other foraging conditions. In 1906-07, despite the mildness of the winter, red- heads were found in Illinois only in the southern zone, where the population num- bered only 38,000 birds, mostly in forest. By contrast with the flicker, the red-head made little use of cornstalk habitat. In 1956-1958, red-headed woodpeckers were found in forest in both the central and southern zones, and state populations num- berd 92,000 (72 per cent in the southern zone) in January, 1957, and 424,000 (98 per cent in the southern zone) in Febru- ary, 1958. The very high winter popula- tion in the southern zone in 1958 prob- ably represented a special concentration, the result of unusually good foraging con- ditions there. The central zone was vir- tually devoid of red-heads, and part of the concentration in the southern zone may have come from states adjacent to Illinois. What the future holds for this species is dificult to predict. There is some evi- dence that red-head populations reached their lowest level before 1957 (but after 1909) and that the populations have come back slightly in recent years. With com- petition for nesting cavities particularly great since the introduction of the star- ling, a notable future increase in the red- head population seems unlikely. Downy Woodpecker.—The downy woodpecker was encountered throughout the state during the surveys about four times as frequently, both in summer and winter, as its congener, the hairy wood- pecker. The downy woodpecker is primarily a forest species, and we can say little about 476 Intinois NatuRAL History SuRVEY BULLETIN population changes, if any, between 1909 and 1957, because of the small acreage of forest sampled in summer in the earlv surveys. Our southern census samples in- dicate that the state population of the downy increased at least slightly between the two survey periods, perhaps because of the spread of forest. The geographic and ecological distribu- tion of the downy woodpecker in the re- cent surveys is of interest. In the sum- mers 1957 and 1958, downies were found in the northern and central zones only in forest, but in the southern zone in both forest and shrub areas. Population den- sities indicated that central zone forests were particularly good for downies. Forest populations were 3.4 birds per 100 acres in the northern zone, 12.2 in the central, and 2.8 in the southern. We estimated that the state breeding population of the downy was about 287,- 000 in 1957 and 219,000 in 1958. (Esti- mates of forest populations are apt to be low if based on the strip census method.) In both years, 53 per cent of the nesting population of the state was in the southern zone and about 40 per cent in the central. The downy woodpecker is supposedly not a migratory species in Illinois. In winter, the downy population, swelled by summer production, extended into many nonforest habitats, our data showed. This ecological extension may be explained by one or more of the following: the natural overflow of a swelled population, the wandering of juveniles, or a change (from summer) in foraging habits by the total populace. Woody habitats (forest, shrubs, and orchards) had the highest population densities in winter; such open-field habi- tats as corn stubble, fallow fields, and pasture also harbored downy populations. Winter population estimates of the downy woodpecker for the state were 322,000 birds in 1906-07, 506,000 in 1956-57, and 507,000 in 1957-58. These figures represented increases over the re- spective summer populations of about 2 to 1; the ratio was not the same in all zones. About 60 per cent of the state population was in the southern zone, only 10-15 per cent in the central zone, and 25-30 per cent in the northern zone. These figures mean that winter popula- tions in the northern and southern zones Vol. 28, Art. 3 increased greatly over their respective summer populations, as expected, while the winter population in the central zone actually fell below the summer population there. The distribution pattern is exceed- ingly perplexing, but, because the pattern was consistent in all census years, we feel that it represents a genuine biological phe- nomenon. The data suggest that there is at least one migratory population of downies in the state; distribution, both winter and summer, in this species needs careful and detailed study. With increased acreage of forest, and almost unlimited areas of winter forage habitats (corn, fallow fields, pasture, shrub, and forest), the future for this species looks bright. Eastern Kingbird. — Six species of summer resident flycatchers (eastern king- bird, crested flycatcher, phoebe, Acadian flycatcher, Traill’s flycatcher, and wood pewee) were encountered during the sum- mer surveys. The eastern kingbird was fairly uniformly distributed in the three zones of the state in 1907-1909, but pop- ulations tended (all census years) to be most dense in the northern zone, least dense in the southern. For example, pas- tureland in 1907-1909 had 4.7 kingbirds per 100 acres in the northern zone (5.7 in 1957-1958), 3.4 in the central (1.7 in 1957-1958), and 2.5 in the southern (0.0 in 1957-1958). Populations in the south- ern zone were particularly low in the re- cent census years. In 1957-1958, shrub- grown areas had densities of 9.3 kingbirds per 100 acres in the northern zone, 8.2 in the central, and 0.8 in the southern. The eastern kingbird occurred in all census years in virtually every summer habitat censused; particularly favored were edge shrubbery, farmyards, shrub- grown areas, savanna-type areas, and or- chards. Densities of kingbird populations in various habitats in the northern zone in 1957-1958 were 33.5 birds per 100 acres in edge shrubs, 9.3 in shrub-grown areas, 7.2 in savanna-type areas, 6.2 in fallow fields, 5.7 in pasture (4.7 in 1909), 1.8 in red clover, 1.4 in both mixed hay and mowed hayfields (2.8 in 1909), and 0.3 in cornfields (1.7 in 1909). In 1907- 1909, farmyards of the state had 7.3 king- birds per 100 acres; orchards in the south- ern zone had 6.6 per 100 acres (3.8 in October, 1963 GraABeR & GRABER: 1957-1958). Frequently used (all census years) foraging habitats in the central and southern zones were plowed fields (2.5 birds per 100 acres), oat fields (1.6), and ungrazed grassland (1.4). Population densities in favorite habitats were roughly similar in 1907-1909 and 1957-1958, but densities in marginal habitats, such as cornfields, indicated that there had been a decline in the kingbird population be- tween 1909 and 1957. Our estimates of the state breeding populations of this species were 662,000 in 1909 (about 650,000 in 1907, esti- mated from central and southern popula- tions), 307,000 in 1957, and 226,000 in 1958. The decline was particularly strik- ing in the southern zone, where the king- bird population fell from about 350,000 birds in 1907-1909 to less than 100,000 in 1957-1958. Because the tyrant flycatchers are no- tably aggressive in competing with other species, competition would seem an un- likely factor in the decline of the kingbird. Habitat changes between 1909 and 1957 probably had a marked effect on the king- bird population. Areas of two important kingbird habitats, orchards and pasture- land, were reduced tremendously. An in- crease in forest areas probably eliminated some kingbird habitat, and reduction in the numbers of farmsteads and hedgerows in recent years removed some prime nest- ing habitat. It is possible that changes in the insect fauna had an effect on the king- bird population. The fact that the 1957- 1958 densities in orchards were notably below the 1907-1909 level suggests that modern methods of orchard management do not favor the kingbird. Because road- side vegetation (hedges and shrubs) pro- vides an important habitat for kingbirds, roadside spraying with herbicides and in- secticides may have played an important role in the decline. Horned Lark.—In all census years, the horned lark was recorded throughout the state, both summer and winter, in all open-field habitats. Summer population densities for the lark were notably lower (all census years) in the southern zone than in the central and northern zones. For example, cornfields in 1957-1958 had 32.9 larks per 100 acres in the northern zone and 32.2 in the central zone, but Birp PorpuLaTIons IN ILLINOIS 477 only 4.7 per 100 acres in the southern zone. In certain habitats, particularly hay types, there was marked difference be- tween northern and central zone popula- tions. In 1957-1958, population densities in alfalfa fields were 112.9 larks per 100 acres in the central zone and 11.6 in the northern; densities in red clover fields were 96.8 in the central zone and 0.4 in the northern. Densities of horned lark populations in various summer habitats in the central zone in 1957-1958 were 149.8 birds per 100 acres in plowed fields, 112.9 in al- falfa, 96.8 in red clover, +6.6 in soybeans, 32.2 in cornfields (6.6 in 1907-1909), 31.9 in sweet clover, 24.2 in small grain stubble, 11.4 in oat fields (5.0 in 1907- 1909), 6.0 in ungrazed grassland, 5.5 in fallow fields, 4.1 in pastures (5.4 in 1907-— 1909), and 3.4 in mixed hay (0.8 in 1907-1909). In the northern zone in 1957-1958, sand prairie had 130.5 larks per 100 acres. No Illinois species increased more dra- matically between 1909 and 1957 than the horned lark. Besides the population in- crease, there was an apparent change in the habitat of the lark between the two census periods; this habitat change had great bearing on the population increase. The change was probably in progress even in 1907-1909, when the lark was much more of a grassland species than in the later census years. While the statewide population increased enormously, densities in pastureland actually decreased after 1909. From the natural grassland situa- tion, the lark has moved in increasing numbers to cultivated habitats (corn, soy- beans, and hay legumes), most of them associated with row-crop agriculture. This move was from a diminishing to an ex- panding habitat. Modern land manage- ment seems almost specifically designed to favor the lark. The row-crop acreage is excellent lark habitat in spring and early summer, but in midsummer, as the crops grow, this acreage loses its attractiveness to the lark. Harvesting of hay and small grain in midsummer opens up a vast new acreage, and the lark population shifts to the cut fields. In the northern zone in 1957-1958, mowed hayfields had 37.4 larks per 100 acres, a density about com- parable to that in row crops in early June. 478 The modern practice of mowing roadsides also favors the lark. In June, 1909, the statewide population of the horned lark was estimated to be about 842,000 birds, most of them in the northern (46 per cent) and central (38 per cent) zones. The 1907 statewide sum- mer population was higher, but probably numbered less than 1,500,000 larks (no census in northern zone). In June, 1957, the state population of larks numbered about 5,621,000 birds and, in June, 1958, 4,477,000. As in 1907-1909, most of the horned lark population in 1957-1958 (85-90 per cent) was in the northern and central zones, but the center of abundance had shifted southward to the central zone. The June counts did not represent strictly the breeding populace. We did not in- clude identifiable juveniles in our popula- tion calculations, but, as horned larks nest early in spring, some well-grown juveniles were probably counted as adults. Inclusion of some juveniles in the counts was prob- ably a source of some of the year-to-year variation noted above. Early spring (Feb- ruary-March) temperatures were above normal in 1957, but abnormally low in 1958. Nesting was probably delayed in 1958, and the count for that year may have included few juveniles. The entire winter and early spring of 1908-09 had above-normal temperatures, and the count for June, 1909, may have had a higher proportion of juveniles than either the 1957 or the 1958 counts. Winter habitats for the lark were the winter counterparts of the summer habi- tats (corn stubble or stalks, bean stubble, small grain stubble, winter wheat) and in- cluded virtually all open-field areas. In 1906-07, corn stubble, pasture, small grain stubble, and wheat, listed in order of preference, were the most favored win- ter habitats; in 1956-1958, bean stubble, alfalfa, and mechanically picked corn were the preferred habitats. Modern ag- riculture favored the lark even in winter. The cornstalk habitat (corn picked by hand and the stalks left standing), which covered much of the winter landscape in 1907-1909, was virtually unused by the lark, while the less abundant corn stub- ble was a favorite winter habitat of the species. Mechanized corn picking all but Intinois NatruRAL History SURVEY BULLETIN Vol. 28, Art. 3 eliminated the standing cornstalk habitat, which favored many other species of birds in winter, and vastly increased a habitat that favors the lark. Winter populations of the horned lark in the state numbered about 2,416,000 birds in 1906-07, 9,175,000 in 1956-57, and 7,634,000 in 1957-58. In all census years, the ratio between winter and sum- mer populations for the state was 1.6 or 1.7 larks in January to 1.0 the following June. The constancy of this ratio is sur- prising; it may provide a clue to the re- productive increment in this species, but further study on the natural history of the horned lark is needed before we can un- derstand the significance of the ratio. Al- though this ratio was constant from year to year, it was not constant from zone to zone. The winter-summer ratios for the different zones imply that horned lark populations in the northern part of the state shifted southward in winter. In 1956-57, for example, the northern zone had only 0.6 lark in January to 1.0 in June and the central zone had 1.3 larks in win- ter to 1.0 in summer; the southern zone had 6.5 larks in winter to 1.0 in summer. At the time of the recent survey, the fu- ture outlook for the horned lark in Illinois appeared to be entirely favorable. Barn Swallow.—Of the six species of swallows (tree, bank, rough-winged, barn, and cliff, and the purple martin) encoun- tered in the summer surveys, the barn swallow was undoubtedly the commonest member of its family. At the time of the early series of censuses, this bird was most abundant in the northern zone and least abundant in the southern. In the 50 years that followed, this species increased in numbers, particularly in the southern zone. In 1957-1958, the barn swallow was most abundant in the southern zone, least abundant in the northern. Population densities of the barn swallow over alfalfa fields in 1957-1958 were 4.4 birds per 100 acres in the northern zone, 24.0 in the central zone, and 38.8 in the southern zone. The barn swallow was seen foraging in summer in a great variety of open-field habitats; it favored edge shrubs, alfalfa, sweet clover, pastures, and ungrazed grass- lands. Population densities for various foraging habitats of the state in 1957- October, 1963 GraperR & GRABER: 1958 were 26.3 swallows per 100 acres over edge shrubs, 13.1 in alfalfa, 11.8 in sweet clover, 9.6 in pastures (1.7 in 1907— 1909), 7.5 in ungrazed grasslands (27.0 in 1907-1909), 4.2 in red clover (5.2 in 1907-1909), 4.2 in mixed hay (3.3 in 1907-1909), 3.5 in oats and wheat (0.5 in 1907-1909), 3.4 in fallow fields (6.2 in 1907-1909), and 1.7 in corn and soy- beans (0.2 in 1907-1909). Ungrazed grassland, fallow fields, and red clover, the favored habitats in 1907-1909, ap- parently lost some birds to alfalfa, a crop that increased greatly after 1909. Edge habitats, such as roadsides and drainage ditches, appeared to have high numbers of foraging barn swallows. Cutting enhanced fields of wheat and hay as foraging areas for swallows. State population estimates for this spe- cies were 300,000 birds in June, 1909, and 910,000 in June, 1957. The 1907 popula- tion was probably even lower than 300,- 000 (no northern zone census in 1907), and the 1958 population was probably over 1,000,000. The barn swallow is an- other of the species that increased greatly between the early and later surveys. Not only did population densities of the barn swallow in some favored foraging habitats (notably pastureland) increase between the two census periods; certain habitat changes favored the barn swallow. Alfalfa, one of the best habitats, became a dominant hay crop in I]linois, and other hay crops proved to be good foraging habi- tats for the barn swallow. Barns, important nesting sites for the barn swallow, were probably less plentiful in 1957-1958 than in 1907-1909, but ce- ment culverts and bridges were more nu- merous. The barn swallow may recently have made increased use of culverts and bridges for nesting sites. The increasing use of potent insecticides may ultimately create problems in food acquisition for the barn swallow and other insectivorous birds, but land management practices in Illinois in 1958 appeared to favor the barn swallow and some other species of swallows. Blue Jay.—The blue jay was recorded throughout the state, both summer and winter, in all census years. In summer, the jay occurred in a va- riety of woody and open-field habitats and Birp PoPpuULATIONS IN ILLINOIS 479 showed some interesting regional varia- tions in habitat preference. For example, in cornfields, a marginal foraging habitat, the jay was notably more numerous in all census years in northern Illinois than in the central or southern zones. In forests, population densities of the jay were high- est in the central zone, lowest in the southern; in urban residential areas, jay populations were most dense in the south- ern zone. In some other habitats, pasture- land, for example, there was little varia- tion in the jay population from one zone to another. In most summer habitats for which comparative figures are available, blue jay population densities were higher in 1907— 1909 than in 1957-1958. In 1907-1909, the most favored blue jay habitats were forests, orchards, and residential areas. In 1957-1958, the species was numerous in residential areas and in hedgerows and edge-shrub habitat (neither of the last two habitats was censused in 1907-1909). Summer population levels of the blue jay in various habitats of the state in 1957— 1958 were 67.6 birds per 100 acres in hedgerows, 30.0 in edge shrubs, 17.7 in residential areas (11.9 in 1907-1909), 8.0 in savanna-type areas, 6.6 in forest (33.3 in 1907-1909), 4.1 in orchards (20.7 in 1907-1909), 3.2 in shrub areas (16.1 in 1907-1909), 1.4 in pastureland (2.5 in 1907-1909), 0.4 in fallow fields (2.5 in 1907-1909), and 0.3 in cornfields (1.1 in 1907-1909). The state blue jay population declined greatly between 1909 and 1957. Our esti- mates of the state population were 1,300,- 000 in 1907 (estimate based on central and southern zone populations), 1,557,- 000 in 1909, 460,000 in 1957, and 470,- 000 in 1958. The loss was apparent in all zones, but it was particularly great in the southern zone (81 per cent decline in southern zone, +7 per cent decline in northern and central zones). The population decline in this species is surprising. The blue jay is a versatile species, nesting as it does in a variety of woody habitats. Forest, a favored habitat in 1907-1909, increased in acreage, but jay populations in forest had become rela- tively sparse by 1957. In orchards, a diminished habitat, recent jay populations were thinner than those of 1907-1909. 480 The ecology of the blue jay appears to be changing. Of all its summer habitats, only residential areas appeared to have higher populations in the recent census years than in 1907-1909. In northern Ili- nois in 1907-1909, the bulk of the jay population was in forest, but, in 1957— 1958, most of the population was in resi- dential areas. The causes for this change are not apparent. Gross habitat changes since 1909 appear to have been beneficial, not harmful. The fact that the jay pop- ulation thinned in favorite habitats sug- gests such possible causative factors as competition, reduced availability of food, or disease (in essence, reduced productivity or increased mortality). We can only sug- gest that further study of this species ts needed. Some blue jay populations are migratory. The jays that winter in Illinois could rep- resent breeding populations from states to the north, resident Illinois populations, or a combination of the two population groups. In 1906-07, the winter population of jays was estimated to number $33,000 birds (compared to 1,300,000 the follow- ing June); about 81 per cent of the state winter population was in the southern zone. In 1956-57 and 1957-58, the state winter populations (461,000 in 1956-57, 570,000 in 1957-58) were slightly higher than breeding populations in the follow- ing summers, but, like the summer popu- lations, still far below the levels of the early census years. To determine pre- cisely what happens in these population shifts and changes, there is need for an intensive blue jay banding program. The principal winter habitats of the blue jay in all census years were shrub, forest, and orchard. Jays made relatively little use of open-field winter habitats in the recent census years, although in 1906-— 07 they had frequented (in sparse num- bers) cornstalk habitat and pastureland. Gross changes in winter habitats do not appear to have been responsible for reduc- ing the jay population. Common Crow. —In summer and winter (all census years), the common crow was counted within the census strips in all zones of the state and in virtually every habitat. Crow distribution in the three zones was quite uniform, reflecting total acreage distribution; largest numbers Iturinois NAtuRAL History SURVEY BULLETIN Vol. 28, Art. 3 of crows were in the southern zone, small- est in the northern, both summer and winter. Hedgerows, orchards, and forests were the habitats with the highest population densities of crows. Populations in most habitats were higher in 1907-1909 than in 1957-1958. Densities of crow popula- tions in various summer habitats of the state in 1957-1958 were 15.0 birds per 100 acres in hedgerows, 5.4 in forest (6.4 in - 1907-1909), 3.6 in sweet clover, 2.7 in plowed fields, 2.1 in ungrazed grassland and marshland, 2.0 in edge shrubs, 1.9 in shrub-grown areas (4.7 in 1907-1909), 0.5 in pastures (2.2 in 1907-1909), and 0.5 in cornfields (1.7 in 1907-1909). In addition, in 1907-1909, crows were found in orchards (13.5 per 100 acres), cut and shocked wheat fields (8.9 per 100 acres, in contrast to 0.2 in standing wheat), red clover (2.5), fallow fields (1.8), oat fields (1.7), and mixed hay (1.2). Like the blue jay, the crow should pre- sumably have benefited from gross habitat changes in the half century between census periods but, like the jay, the crow ap- parently declined in numbers. In June, 1909, the state crow population, accord- ing to our estimate, numbered about 1,- 227,000 birds. In June of 1957 and 1958, state crow populations were, respectively, 342,000 and 290,000 birds. There was no northern zone census in 1907, but crow populations in both 1907 and 1909 were well above the 1957-1958 levels. Gross habitat changes, except possibly those that reduced food resources, prob- ably were not the primary causes of the decline. In terms of percentage, the de- cline was about the same in the two cor- vids, the blue jay and the crow. Both species showed declines in population den- sitv in favorite habitats. In winter, crows were distributed throughout the state in all census years, but the central zone had by far the larg- est part of the state population. In all census years, also, the state crow popula- tion in winter was at least two to four times as large as that in the following summer. Estimates of the state January populations were 4,805,000 in 1907 and 1,387,000 in 1957. In February, 1958, the crow population numbered about 443,000, a figure implying that dispersal of the October, 1963 Graper & GRABER: winter population was well along at that time of year. Much of the difference between the winter populations and the summer popu- lations must represent immigration of crows from breeding grounds north of Illinois. Cornstalks, corn stubble, small grain stubble, pasture, and forest were found to be important winter habitats for the crow. Like the summer data, the winter popu- lation figures show that crow numbers decreased between the two census periods. Furthermore, in terms of percentage change, the winter population decline matched the summer population decline almost exactly: summer, 72 per cent de- cline; winter, 71 per cent. Because some of the winter crow population in Illinois comes from other breeding grounds, these data imply that the decline in crow num- bers occurred over a broad geographic area. Gross changes in winter habitats be- tween 1909 and 1956, which should have favored the crow, offer no explanation for this decline. There was more woody cover in 1956-1958 than in 1906-1909. and food was probably more abundant in re- cent years as use of mechanical harvesting techniques increased. The causes of the decline, whatever they were, may have been the same as those that caused a de- cline in the blue jay. Chickadees.— Both species of chicka- dee, the black-capped and the Carolina, were recorded in summer and winter within the census strips, but nonsinging chickadees are so difficult to identify to species that we have had to combine data for the two species. Chickadees in the northern zone were undoubtedly black- caps. The Carolina was probably the com- mon breeding species in the southern zone. Both species occurred in the central zone, and, in winter, both may have occurred in the southern zone. In summer, chickadees were virtually restricted to habitats with some woody cover (forest, orchard, shrubs, and, to a much lesser extent, pasture). Because forest census samples were small in 1907- 1909 (though probably adequate in the southern zone), we shall place emphasis on the recent population data. Population densities, especially those for the black-cap Birp PoPpuULATIONS IN ILLINOIS 481 in the northern zone, were remarkably similar in 1957 and 1958. In forest, the principal habitat, chickadee summer popu- lations in 1957-1958 were 15.8 birds per 100 acres in the northern zone (black- cap), 10.3 in the central zone (both species), and 11.3 in the southern zone (Carolina). In shrub areas, summer den- sities were 6.2 chickadees per 100 acres in the northern zone, 8.2 in the central, and 8.7 in the southern. In edge shrub, sum- mer densities were 16.7 per 100 acres in the northern zone and 30.0 in the south- ern. The data suggest that the Carolina chickadee may make greater use of shrub habitats than does the black-cap. Neither species of chickadee was reported in resi- dential areas to a significant extent in either census period. The available data suggest that the Carolina chickadee was more numerous in 1957-1958 than in 1907-1909. In the southern zone, the summer population of the Carolina chickadee did not number more than about 78,000 birds in 1907- 1909, according to our estimate; chickadee populations of the southern zone num- bered about 400,000 birds in 1957 and 300,000 in 1958. Even if the forest seg- ment of the chickadee population for 1957-1958 were disregarded, the recent populations would exceed those of the early census years. Because the forest cen- sus sample for northern and central [lhi- nois was small in 1907-1909, and because the black-cap is definitely a forest species, we cannot speculate on population trends in this species. It is worthwhile to consider the 1957- 1958 data on chickadee populations in more detail. Chickadee distribution tended to follow the distribution of woody habi- tats (greatest number of chickadees in the southern zone, smallest number in the northern). Far more summer habitat was available to the Carolina (in the southern zone) than to the black-cap (in the northern). The “unbalanced” habitat dis- tribution may in part account for the higher black-cap population densities in the northern zone. We estimated that in summer the state population of chickadees (both species) numbered about 600,000 in 1957 and 460,000 in 1958. The north- ern zone had only about 82,000 chickadees (black-cap) in each year, while the south- 482 ern zone had about 400,000 (Carolina) in 1957 and 300,000 in 1958. The central zone had about 120,000 birds (both spe- cies) in 1957 and 80,000 in 1958. In winter (all census years) chickadees invaded a large number of habitats, in- cluding fallow fields, corn stubble, hay- fields, and even bean stubble and plowed fields, but, as in summer, woody types comprised the principal habitats. Chickadees (at least the black-cap) ap- peared to be somewhat migratory. From the summer population levels in 1957, the 1957-58 winter chickadee populations de- clined in the northern zone, remained about the same in the central zone, and doubled in the southern. Migration is im- plied in these data; in a nonmigratory spe- cies, we should expect that in each zone the winter population would be greater than the previous summer population. The census data indicate that there was some change in numbers of the black- cap, or in distribution of the black-cap, between 1907 and 1956. In both 1906-07 and 1956-57, the state winter population of the chickadees (both species) num- bered about 1,000,000 birds, but chickadee distribution was very different in the two years. January populations for the north- ern zone were 230,000 in 1906-07 and 63,000 in 1956-57; for the central zone, 226,000 in 1906-07 and 105,000 in 1956- 57: and, for the southern zone, 660,000 in 1906-07 and 830,000 in 1956-57. In January, most of the chickadees in the northern and central zones must have been black-caps, and their numbers were about three times as great in 1906-07 as in the recent census winters. Without bet- ter summer data, we cannot say that this apparent decline represents a real change in total numbers of the black-cap; the difference between the 1906-07 and 1956- 57 populations may represent a change in winter distribution of the black-cap, or merely “natural” annual variation. Addi- tional information is needed on the distri- bution of both species of chickadees, par- ticularly on their migrations. Tufted Titmouse. — The tufted tit- mouse, like the chickadees, is primarily a forest species. It is virtually restricted to habitats with some woody cover. We have meager summer data on this species for 1907-1909, except for the population of Intinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 the southern zone. In recent censuses, the tufted titmouse was found in all three zones of the state, but populations were very low in the northern zone. For example, summer population densities (1957-1958) in forests were about 20 titmice per 100 acres in the southern and central zones and only 0.6 per 100 acres in the northern zone. Southern zone popu- lations of the titmouse in various summer habitats in 1957-1958 were 19.3 birds per 100 acres in forest (14.2 in 1907-1909), 9.4 in shrub-grown areas (5.3 in 1907- 1909), 5.1 in edge shrub and residential areas, and 1.3 in orchards (13.3 in 1907- 1909). A density of about 20 titmice per 100 acres may represent a kind of satura- tion level for central and southern LIlli- nois forests. The recent thinning of popu- lations in orchards (despite increases in other habitats) is a pattern observable in other species, as well as the titmouse. The tufted titmouse increased in num- bers between 1909 and 1957, at least in the southern zone, where the June popu- lation was about 324,000 birds in 1907- 1909 and 550,000 in 1957-1958. There is no reason to doubt that the population increased northward, also. In 1957-1958, there were about 200,000 titmice in the central zone and about 20,000 in the northern. Our estimates for the entire state were 752,000 titmice in 1957 and 756,000 in 1958. If these figures are rep- resentative, they indicate that the titmouse population is one of the least variable for which we have data. The increase in ‘forest acreage has surely been beneficial to the titmouse, but the fact that forest populations of this species increased in density shows that other factors than habitat change entered into the population increase. Both the tit- mouse and the Carolina chickadee are cavity nesters. Because of their small size, they probably have little competition from the larger forest species, but they may compete with one another. The northward advance of the titmouse may have had some effect on the black-capped chickadee. The occurrence of the titmouse (but not the chickadees) in the urban residential areas censused is of ecological interest; at present this habitat accounts for only a very small fraction of the titmouse popu- lation of the state. October, 1963 Graper & GRaBER: Winter distribution of the tufted tit- mouse through the state, the surveys showed, was similar to the summer dis- tribution. In winter, the titmouse held to the woody habitats more than did the chickadees. The tufted titmouse is not known to be migratory; yet, in both of the recent census years, the state winter population was below the following sum- mer population. We estimated that the state population of the titmouse numbered about 670,000 birds in January, 1957 (750,000 the following June), and 470,- 000 in February, 1958 (760,000 the fol- lowing June). Such a pattern of seasonal fluctuation suggests the possibility of mi- gration. There are few other data to cor- roborate such a view, and we should con- sider other possibilities. The titmouse probably begins nesting in April, and the February census figure may represent the adult breeding population better than the June figure. By June, many juveniles may be flying; the juvenile plumage in this spe- cies is similar to the adult plumage, and the June count may include many im- matures. Mockingbird.—In summer of all cen- sus years, the mockingbird was encoun- tered in central and southern Illinois, but, in winter, this species was seen within the census strips only in the southern zone. The central Illinois population was al- most negligible in the early census years; in 1957-1958, population densities of the mocker in central Illinois were only about one-third of the southern Illinois densities. Principal summer habitats for the mockingbird were residential areas and or- chards in 1907-1909 and edge shrubs (not censused in 1907-1909) in 1957-1958. Densities of mockingbird populations in various habitats of southern Illinois in 1957-1958 were 40.5 birds per 100 acres in edge shrubs, 2.6 in orchards (17.7 in 1907-1909), 1.0 in residential habitat (24.2 in 1907-1909), 0.8 in pastures (2.7 in 1907-1909), 0.8 in shrub-grown areas (2.7 in 1907-1909), and 0.4 in cornfields (2.5 in 1907-1909). In addition, in 1907- 1909, fallow fields had 4.1 mockers per 100 acres, and plowed fields had 2.2 per 100 acres. The density data indicate a decline in the state mockingbird populations between 1909 and 1957. Our estimates of summer Birp PopuLations tn ILLINOIS 483 populations in the southern zone were 184,000 in 1907, 386,000 in 1909, 89,000 in 1957, and 54, 000 in 1958 (the 1907- 1909 fienres do not include edge shrub, but the 1957-1958 figures do). While mockingbird numbers for the state and for the southern zone diminished between 1909 and 1957, the numbers for the cen- tral zone increased notably. In the sum- mers of 1907-1909, there were probably fewer than 5,000 mockers in the central zone, but northward extension brought the cnet in this zone to about 31,000 birds in 1957. The number was down in 1958 (perhaps as low as 15,000), but it still far exceeded the 1907-1909 level. Even with the geographically extended population, the total number of mocking- birds in the state in 1957 (120,000) was below the 1907 figure (more than 184,- 000). The combination of geographic ex- tension and thinning population can be observed in a few other species, for ex- ample the turkey vulture. Why the mock- ingbird population thinned in the south- ern zone we cannot say. Except for or- chards and pastureland, mockingbird habi- tats should have been nearly as extensive in 1957-1958 as in 1907-1909. The spe- cies now seems overly dependent on one type of habitat, edge shrubs, a habitat that is being eliminated by modern farming practices. A hopeful development is the increase in recent years of multiflora rose hedges, which are much favored by the mockingbird. By winter each year, the mockingbird population has shifted southward in IIli- nois, and, though a few birds may winter in the central zone of the state, the spe- cies was recorded within winter census strips in 1906-07, 1956-57, and 1957- 58 only in the southern zone, in habitats that were the winter counterparts of the summer habitats. The mockingbird popu- lations in Illinois numbered about 63,000 birds in January, 1907, and 39,000 in January, 1957. The population level in February, 1958, was much higher (187,- 000), probably because spring migration was under way and migrants were concen- trated in the latitudes of southern Illinois. Catbird.—In all census years, the cat- bird was found throughout the state in summer. It occurred in a variety of habi- tats (urban areas, forest, orchards, shrubs, 484 pastures, oats, wheat, corn, hayfields, and marsh), but in greatest densities in woody types. Population densities varied greatly from zone to zone and in no consistent pattern. In the summers of 1957-1958, densities in forest were 2.2 catbirds per 100 acres in the northern, 7.5 in the central, and 0.3 in the southern zone; densities in resi- dential areas were 0.6 in the northern, 4.0 in the central, and 22.4 in the southern zone. Catbird populations in woody habitats in southern Illinois (the zone for which we have the best data for both census periods) were, for 1957-1958, 22.4 birds per 100 acres in residential areas (12.1 for 1907-1909), 5.1 in edge shrubs (14.3 for 1907-1909), 2.6 in or- chards (26.5 for 1907-1909), and 0.8 in shrub-grown areas (2.0 for 1907-1909). In northern and central Illinois, the cat- bird (like the brown thrasher, but unlike the mockingbird) greatly favored hedge- rows (1957-1958 population density: 152.7 catbirds per 100 acres). In northern Illinois, wheat fields were a favorite for- aging habitat. We estimated that the statewide sum- mer population of catbirds numbered about 196,000 in 1957 and 220,000 in 1958. We lack data on the prime woody habitats in northern and central Illinois for 1907- 1909, but, even without the catbirds in these habitats, the state population in 1909 numbered at least 278,000 catbirds. The 1907 population was lower (no northern zone census in 1907), but probably it was close to 200,000. If we make allowance for the uncensused woody habitats, we conclude that the catbird population in the state declined considerably between 1909 and 1957. Brown Thrasher.— Of the three mimids (mockingbird, catbird, brown thrasher) in Illinois, the brown thrasher was by far the most abundant in all cen- sus years. The thrasher occurred in sum- mer in all zones of the state, but, in 1907- 1909, most of the state population was in the southern (especially) and _ central Zones. The brown thrasher was counted in all summer habitats except soybean fields, but this species particularly favored hedge- rows and edge shrubs. Population densi- ties varied from zone to zone and in fa- Intinors NarurRAL History SURVEY BULLETIN various ° Vol. 28, Art. 3 vorite habitats tended to be highest (all census years) in the central and southern zones. In 1957—1958, thrasher populations in hedgerows were 62.9 birds per 100 acres in the northern, 188.7 in the central, and 137.0 in the southern zone; in edge shrubs, 60.9 in the northern, 68.5 in the central, and 75.9 in the southern zone; in shrub areas, 27.8 in the northern, 12.2 in the central, and 2.4 in the southern zone. In other habitats, densities tended to be more nearly uniform from one zone to another. Densities of brown thrasher populations in various summer habitats of the state for 1957-1958 were 11.6 birds per 100 acres in orchards (23.2 for 1907-1909), 3.6 in sweet clover, 3.5 in residential areas (23.8 for 1907-1909), 2.1 in forests (15.4 for 1907-1909), 1.6 in fallow fields (2.7 for 1907-1909), 1.0 in pastures (4.9 for 1907-1909), 0.4 in alfalfa, 0.3 in corn (1.6 for 1907-1909), 0.0 in red clover (8.0 for 1907-1909), 0.0 in mixed hay (2.9 for 1907-1909). Ecologically, the thrasher was the most broadly distributed of the mimids. As the density data imply, the brown thrasher population declined greatly be- tween 1909 and 1957; the decline in this species was more marked than in either of the other mimids. State summer popula- tions, according to our estimates, were about 1,558,000 thrashers in 1909 (1,- 172,000 in 1907 in the central and south- ern zones), +31,000 in 1957, and 402,000 in 1958. The 1907-1909 estimates do not include birds in the high-density edge- shrub and hedge habitats; so the differ- ence between populations in the two pe- riods was even more marked than our figures show. Habitat changes, such as the reduction in orchard acreage and the elimination of many hedges, undoubtedly affected brown thrasher numbers, but such changes could account for only a small part of the total population loss. As in the other Mimidae and some of the other species studied, the thrasher’s population decline, though gen- eral, was particularly marked in the south- ern zone of the state. To explain these changes, we need to know more about the basic biology of each species. Perhaps we — are seeing the mimid population and the population of some other species in a pe- — October, 1963 Graper & GRABER: riodic low; in the future, the numbers may increase or they may continue to de- cline. Whatever the trend, the need for future measurements of the populations is certainly indicated. Robin.—Of the three thrushes (wood thrush, robin, and bluebird) recorded as nesting in Illinois in all years of the sur- veys, the robin was by far the most abundant. In summer, the robin was found throughout the state in most of the habi- tats censused. Residential areas were clear- ly the favorite robin habitat in summer, at least in recent vears. Orchards, edge shrubs, and hedgerows also were high density habitats. Robin populations varied from zone to zone. In 1907-1909, popu- lation densities tended to be highest in the southern zone of the state, lowest in the northern zone. In 1957-1958, densities tended to increase with north latitude. Residential areas in 1907-1909 had 27.8 robins per 100 acres in the northern, 33.5 in the central, and 36.3 in the southern zone, while, in 1957-1958, these areas had 132.2 in the northern, 108.6 in the central, and 101.9 in the southern zone. In forest, the 1907-1909 summer den- sities were 6.4 robins per 100 acres in the central and 15.0 in the southern zone; the 1957-1958 summer densities were 6.1 in the central and 0.3 in the southern zone. Robin numbers apparently increased greatly in residential areas between 1909 and 1957, but, in many other habitats, the numbers were greater in the early than in the later census years. Summer den- sities in various habitats of the state for 1957-1958 were 60.0 robins per 100 acres in hedgerows, 24.6 in edge shrubs, 6.6 in orchards (34.9 for 1907-1909), 5.1 in ungrazed grassland in the northern and central zones (6.8 for 1907-1909), 1.9 in pastureland (7.3 for 1907-1909), 1.9 in shrub-grown areas (3.1 for 1907- 1909), 1.8 in mixed hay (1.8 for 1907- 1909), 1.4 in red clover (4.3 for 1907- 1909), 0.9 in corn (1.6 for 1907-1909), and 0.7 in oats (0.5 for 1907-1909). Population densities of the robin in most summer habitats decreased between 1909 and 1957. We estimated that the state population in June numbered about 1,900,000 robins in 1909 (in 1907 prob- ably about 1,400,000), 1,500,000 in 1957, Birp PopuLaTIONS IN ILLINOIS 485 and 1,360,000 in 1958. The geographic and ecological distribution of the robin seems to have changed. In the summers of 1907 and 1909, the robin population was fairly uniformly distributed through- out the state. Forest and pastureland ac- counted for the bulk of the 1907-1909 summer population, but the robin was well represented in a variety of other habitats. It was an ecologically broad spe- cies. In 1957-1958, most (65 per cent) of the Illinois robins were in the northern zone. The robin was primarily (75 per cent of the state population) an inhabitant of man’s communities (urban residential areas and farmyards). Reduction of pas- tureland probably hurt the robin, but residential areas provided the essential requirements (tree nesting sites and clipped grass foraging areas) of the pasture habi- tat and perhaps improved on this habitat. One possible disadvantage of this speciali- zation in habitat is that the use of chem- icals (insecticides and herbicides) toxic to robins is especially prevalent in urban areas. Except for the possible danger from these chemicals, the future for the robin seems bright. In the coming decades, ur- ban areas are sure to increase. In winter, a few robins may be found even in the northern zone of the state, but, within the census transects, this spe- cies was found in only the southern zone in the winter of 1906-07 and in only the southern and central zones in the winters of 1956-1958. The primary winter habi- tats of the robin were picked (cornstalk ) cornfields, forest, and orchards in 1906— 07 and shrub areas, forest, and pastures in 1956-1958. The robin may have wintered farther north in greater numbers in recent years than at the time of the early survey. In 1906-07, a notably mild winter, the I[lli- nois robin population in January (none recorded in any zone but the southern) was probably less than 100,000 birds. The number of robins in the state in January, 1957, was estimated to be 1,366,000 (all but 15,000 in the southern zone). This population was about the same as the June, 1958, population for the state. In February, 1958, the number of robins was down to 664,000 (none recorded in the central or northern zones). Because the February population showed no north- 486 ward shift, we presume that many winter- ing robins drifted southward in late win- ter before the onset of spring migration. This pattern of movement was similar to that in a number of other species. Eastern Bluebird.—In both survey periods, the eastern bluebird was found throughout the state in summer and win- ter; population densities in summer tended to be highest in the southern zone and lowest in the central. In most years the southern zone had the bulk of the state - population, but in 1958 the bluebird sud- denly all but disappeared from southern Illinois. Favorite summer habitats of the blue- bird were edge shrubs, forest, pastures, and fallow fields, but the bluebird was found also in cornfields, plowed fields, oats, mixed hay, red clover, and marsh. Densities of bluebird populations in var- ious habitats in the southern zone for 1957 were 8.3 birds per 100 acres in pas- tures (2.8 for 1907-1909), 2.6 in fallow fields (3.7 for 1907-1909), 1.7 in forest (6.7 for 1907-1909), 1.5 in shrub-grown areas (1.8 for 1907-1909), and 0.0 in corn (1.7 for 1907-1909). Roadside habi- tats are well-known favorites of the blue- bird, and in 1957, along roads in south- ern Illinois, shrub areas had 33.6 blue- birds per 100 acres and ungrazed grass areas had 10.3 per 100 acres. Most density figures were higher in the early than in the recent surveys. A notable exception to the trend was the recent high-density fig- ure for pastureland. The great loss in pastureland acreage between 1909 and 1957 could have had some concentrating effect on the bluebird population. In June, 1909, the number of bluebirds in Illinois was estimated to be 460,000 (70 per cent in the southern zone) ; the population was higher in 1907 (no north- ern zone census), possibly as high as 600,- 000. In June, 1957, the state had about 220,000 bluebirds (80 per cent in the southern zone) ; by the following summer the population had fallen to an almost unbelievable low of about 50,000 birds. Strangely, the northern zone population was still intact, but the central zone popu- lation was badly decimated and the south- ern zone population was virtually gone. We would have been inclined to doubt our census data, except that at about the I_tinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 same time sharp declines were noted widely by field observers in the eastern United States (James 1962:308). As of October, 1962, the Illinois bluebird popu- lation had shown only slight recovery. In winter (all census years), the south- ern zone had virtually all of the blue- birds in Illinois. The birds were en- countered usually in small flocks and in a variety of winter habitats. In all census years, they frequented forests, shrub areas, ungrazed grasslands, and pasture; in re- cent census years, alfalfa fields. The win- ter populations of the bluebird in Illinois were remarkably similar in the census years, numbering about 680,000 in Jan- uary, 1907 and 1957, and about 720,000 in February, 1958. The number of blue- birds wintering in the northern and cen- tral zones (combined) did not exceed 25,- 000 birds in any census year; in February, 1958, we found no bluebirds outside the southern zone. In comparison with popu- lations of other years, the winter popula- tion of 1957-58 in the southern zone appeared to be about normal as late as mid-February; yet the breeding popula- tions of the southern zone and most of the central zone never appeared. What happened to these populations remains a mystery. Diminished food resources in some areas, coupled with the enduring severe cold of January— March, 1958, would certainly have taken a toll; a num- ber of authors have discussed weather that was harmful to the bluebird (Mus- selman 1941 :409-10; Hancock 1888 :433 ; and others). James (1962:310), in dis- cussing the decline of the bluebird popu- lation in relation to weather, suggested that something other than severe weather alone was responsible for the decline. There is evidence other than the IlIli- nois census data that the decline in blue- bird numbers has been in progress for a long time. Writing about 50 years ago, Barnes (1912:328) felt that the bluebird as a nesting bird was not one-tenth as common as 20 years before and, a few years later, Ridgway (1915:196) noted that the bluebird had been “mainly dis- placed” by another cavity nester, the house sparrow. Starling.—Shortly after being intro- duced successfully into the United States (New York) in 1890, the starling began October, 1963 Graper & GRABER: to extend its range westward. ‘The species had not reached Illinois at the time ot the first survey (19060-1909); it was evi- dently rare in this state in 1926 (Eifrig 1927:432). Today, it is one ot the most abundant species in Illinois. Both in sum- mer and winter of 1956-1958, starlings were seen throughout the state in virtu- ally every habitat. In summer, we found, no other Illinois habitat was as important to the starling as urban areas, and, to a large extent, the distribution of this habitat influenced the distribution of the breeding populations ot the starling in the state. Our data on population densities of the starling in dif- ferent habitats suggest that there was some notable regional variation in the ecology of this bird. In the southern zone, for in- stance, the starling was even more decid- edly an urban resident than in the north- ern and central zones. Urban area densi- ties were about 120 starlings per 100 acres in the northern and central zones and 180 per 100 acres in the southern. In rural habitats, starlings in the southern zone had notable populations in orchards (30.9 per 100 acres, in contrast to 13.6 in the central zone), edge shrubs (high popula- tions in all zones), and corn (8.5 per 100 acres, in contrast to 0.2 in the central zone). For central zone starlings, hay- fields were consistently the favored rural habitats. Starling densities in various types of hay were as follows for the cen- tral zone: 117.1 birds per 100 acres in mowed hay (44.0 for the northern, 0.0 for the southern), 97.9 in red clover (10.9 for the northern, 0.0 for the southern), 48.0 in alfalfa (4.4 for the northern, 0.0 for the southern), and 3.6 in mixed hay (0.7 for the northern, 1.7 for the south- ern). For starlings in the northern zone, the principal rural habitat was pasture- land ; densities were 17.5 starlings per 100 acres in the northern zone, 2.9 in the cen- tral, and 3.3 in the southern. Regional variations in starling ecology may be based on the timing of the breeding season (at different stages in the breeding cvcle, star- lings may forage in different areas). The subject deserves detailed study. Starling populations, even in summer, were extremely variable from place to place and from year to year. This varia- bility reflected the extreme gregariousness Birp PopuLaTIONs IN ILLINOIS 487 (especially great in winter) of the species. Our population estimates for the starling are therefore particularly rough. In IIli- nois, starlings begin nesting in March and April, and by June they have some young on the wing. As the juvenile plumage is distinctive and fairly long-retained, we could segregate juveniles from adults. Our estimate of the state breeding popu- lation, 3,100,000 birds, did not include farmyard habitat, a habitat that may total nearly 200,000 acres and probably harbors a large number of starlings. In winter, the starling was found throughout the state, but, like many other species, it was most abundant in the south- ern zone. In all zones, the most consist- ently favored winter habitat of those cen- sused was small grain stubble. Fallow fields and shrubbery (all types) were also high density habitats in winter. We esti- mated that the state population of star- lings in January, 1957, may have exceeded 11,000,000 birds, over 90 per cent of them in the southern zone. We have inadequate winter data on urban areas, and, consid- ering the extreme gregariousness of the starling in winter, we believe this esti- mate may be very unreliable; however, there can be no doubt that the starling is near the top of the state list of birds in terms of abundance. Yellowthroat.—Of the 22 species of warblers encountered in the course of the surveys (all years), the yellowthroat was the most widespread, ecologically as well as geographically. The yellowthroat was found throughout Illinois in summer, but most of the state population was in the southern zone; densities tended to thin northward. Many of the warblers are primarily forest species, but the yellow- throat frequents a variety of open-field habitats. Edge shrubs, probably the most consist- ently favored yellowthroat habitat, had summer population densities of 24.7 birds per 100 acres in the northern, 106.6 in the central, and 120.0 in the southern zone in 1957-1958. Southern zone population densities of the yellowthroat in various other habitats in 1957-1958 were 139.0 birds per 100 acres along drainage ditches, 91.3 in hedgerows, 84.9 in marshes (9.3 in 1907-1909), 10.9 in shrub-grown areas (26.4 in 1907-1909), 5.9 in red clover, 488 3.9 in orchards (6.6 in 1907-1909), 3.9 in fallow fields (2.5 in 1907-1909), 2.5 in forest (11.7 in 1907-1909), 1.7 in mixed hay (2.1 in 1907-1909), and 0.7 in wheat fields (1.0 in 1907-1909). In 1907-1909, pastures and oat fields had about 1 yellowthroat per 100 acres. The state population of the yellow- throat appeared to change little between 1909 and 1957, either in number or dis- tribution. We estimated that state (sum- mer) populations were about 414,000 birds in 1909 (90 per cent in the southern zone), 362,000 in 1957, and 427,000 in 1958 (80 per cent in the southern zone, both recent census years). House Sparrow.—First successfully introduced into the United States in New York in 1852, the house sparrow was later introduced into other states. At least four introductions were made in Illinois in the period 1868-1876 (Barrows 1889:19). By 1886, virtually the entire state of IIli- nois, as well as a large part of the rest of the United States, was occupied by this species. The urban areas of the country were ideal for the introduced species, and the house sparrow spread through this habitat very rapidly. In all census summers, the densities of house sparrow populations in urban and rural Illinois were highest in the central and northern zones, lowest in the south- ern. In rural cropland habitats, densities were conspicuously high (all census years) in the central zone, but in urban residen- tial areas in recent census years the north- ern zone had the highest populations in the state. For example, 1957-1958 popu- lations in red clover fields were 10.9 spar- rows per 100 acres in the northern zone, 51.2 in the central, and 1.2 in the south- ern, but, in urban residential areas, the densities were 434.8 in the northern zone, 378.3 in the central, and 271.0 in the southern. Residential areas are probably the most important habitat for the house sparrow, but few Illinois species have a more cos- mopolitan distribution. Only from for- ests is this sparrow largely absent. Popu- lation densities of the house sparrow in important summer habitats in the state in 1957-1958 were 373.7 birds per 100 acres in residential areas (265.2 in 1907-— 1909), 195.2 in edge shrubs, 56.4 in un- Intinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 grazed (largely roadside) grassland, 46.1 in orchards (125.5 in 1907-1909), 31.8 in pastures (21.5 in 1907-1909), 22.0 in oats (9.7 in 1907-1909), 20.7 in red clo- ver (11.7 in 1907-1909), 13.1 in alfalfa, 12.3 in mixed hay (16.7 in 1907-1909), 4.8 in corn (4.6 in 1907-1909), 4.2 in soybeans, 3.4 in fallow fields (32.2 in 1907-1909), 3.2 in wheat (29.5 in 1907- 1909), and 0.1 in forest (2.2 in 1907- 1909). In most summer habitats, population densities of the house sparrow in recent census years were higher than those in 1907-1909. Notable exceptions were or- chard, fallow fields, and wheat. House sparrow populations in most habitats de- clined in the southern and increased in the northern zones, and both the density increase of house sparrow populations in oats (a northern zone crop) and the de- crease in wheat (a southern zone crop) were probably related to a general north- ward shift in the population. Despite population increases of the house sparrow in certain habitats, the statewide popula- tions of 1957-1958 were not much greater than that of 1909. We estimated that the state June populations of house sparrows numbered about 5,300,000 birds in 1909 (probably about the same in 1907), 6,- 150,000 in 1957, and 5,500,000 in 1958. The number of immatures in these popu- lations is unknown. Urban populations of house sparrows were much greater in 1957-1958 than in 1907-1909, but rural populations, particularly in the southern zone, probably were’ lower; so the net change for the whole state was not great. Rand (1956:69-70) and others pointed out the probable importance of domestic livestock in the ecology of the house spar- row and suggested that house sparrow populations in cities declined in recent dec- ades because of the disappearance of horses from the streets. Rand also noted that sparrow populations were more dense in suburban areas than in the business dis- tricts of a large city. Obviously, some prime sparrow habitat is being lost as resi- dential areas near the center of the city give way to the business district, but the net change is toward great expansion of good sparrow habitat. The Illinois popu- lation of house sparrows will almost cer- tainly increase in the coming decades. October, 1963 Graper & GRABER: House sparrow populations in open- field habitats (all census years) declined from an average of about 18 per 100 acres in summer to about 3 in winter. Winter brought no conspicuous increase in spar- row numbers in shrub or forest habitat; most of the sparrow population wintered in farmyards and urban areas. ‘There is a parallel situation in the introduced mam- mal, the house mouse, which in spring ex- pands its habitat to open fields and with- draws in fall and winter to human habi- tations. Because we had inadequate data for residential habitats in winter, we could not estimate the state populations of the house sparrow for this season. Bobolink.—In the summer surveys (all years), the bobolink was encountered in both northern and central Illinois, but most of the state population was in the northern zone. “Though the principal summer habitats, hayfields (all types), oats, pastures, and ungrazed grassland, were well represented in the central zone, population densities of the bobolink in this zone were consistently below those in the northern. In mixed hay, for example, there were about 60 bobolinks per 100 acres in northern Illinois, but only 11 in the central zone. Population densities of the bobolink in various summer habitats of the northern zone in 1957-1958 were 62.1 birds per 100 acres in mixed hay (53.1 in 1909), 52.9 in oats (3.7 in 1909), 44.3 in alfalfa, 38.1 in red clover (18.0 in 1909), 13.6 in pastures (5.2 in 1909), and 5.2 in ungrazed grassland (54.1 in 1909). The relatively dry margins of marshes were probably a favored habitat in 1909 (88 bobolinks per 100 acres). The apparent increased use of oat fields by the bobolink (a change that can be seen in other prairie species) helped to balance the loss in acre- age of ungrazed grassland (a favored bob- olink habitat in 1907-1909) and pasture- land. We estimated that the June popula- tions of bobolinks in Illinois were 1,175,- 000 birds in 1909, 1,860,000 in 1957, and 1,360,000 in 1958. In the central zone, the population increased from less than 15,000 birds in 1909 to more than 100,000 in 1957-1958. The statewide increase fits a pattern of population increase and range extension that is observable in several spe- cies of open-field I[cteridae. Birp PoPpuLATIONS IN ILLINOIS 489 Meadowlarks.—In all census years, meadowlarks were encountered through- out the state in both summer and winter, but, because of difficulty in determining the species of nonsinging meadowlarks, we do not know the relative proportions of the eastern and western species. Our data represent both species, at least in the north- ern and central zones. All meadowlarks in the southern zone in summer, as far as we could determine, were of the eastern species. Though specimens were taken in Illinois at least as early as 1876 (Allen 1880:54), the western meadowlark was not sufficiently common to be recorded in the 1907-1909 surveys. In the past 50 years the western meadowlark has greatly extended its range and is now common in both the northern and central zones of Illinois. In most summer habitats, meadowlark populations were more dense in the south- ern than in the northern zone (all census years); after 1909, populations in the northern zone increased in most habitats. For example, in red clover fields, popula- tion densities were, for the northern zone, 29.0 meadowlarks per 100 acres in 1957— 1958 (9.0 in 1909) ; for the central zone, 47.8 in 1957-1958 (17.1 in 1907-1909) ; and, for the southern zone, 49.7 in 1957— 1958 (39.5 in 1907-1909). The fact that meadowlark populations in the northern zone increased suggests that the western meadowlark may have been the species that particularly increased in numbers. In a few habitats, meadowlark populations in the southern zone decreased between 1909 and 1957. In ungrazed grasslands or prairie, for instance, meadowlark popu- lations in the southern zone declined from about 63 birds per 100 acres in 1907-1909 to 50 per 100 acres in 1957-1958, even though in the northern zone populations increased from about +7 birds per 100 acres in 1909 to 80 per 100 acres in 1957-1958. Though the meadowlarks were found (all census years) in all habitats except urban, the most important meadowlark habitats were grasslands and hayfields of all kinds. Summer population densities of the meadowlarks in various habitats of the state in 1957-1958 were 58.0 birds per 100 acres in ungrazed grasslands (63.4 in 1907-1909), 48.2 in sweet clover, 44.2 in 490 alfalfa, 43.2 in mixed hay (44.8 in 1907- 1909), 42.1 in pasture (23.5 in 1907- 1909), 41.1 in red clover (30.9 in 1907- 1909), 20.0 in edge shrubs, 17.9 in fallow fields (45.7 in 1907-1909), 8.0 in oats (6.3 in 1907-1909), 7.1 in marsh (10.4 in 1907-1909), 5.8 in orchards (15.4 in 1907-1909), 4.2 in wheat (9.8 in 1907- 1909), 2.7 in corn (1.9 in 1907-1909), and 2.3 in soybeans. Meadowlark population densities in the several hay crops varied considerably from summer to summer (from as low as 20 birds per 100 acres in one year to as high as 50 the next year in a given crop, such as red clover), but the total number of meadowlarks in all hay crops combined tended to remain fairly constant from summer to summer. These data suggest that in the meadowlarks there may be considerable switching of habitat from one year to the next. In some places, in hay crops of the northern zone, particularly, the density of the meadowlark population in a given crop appeared to vary inversely with density of the redwinged blackbird population. We suspect that the meadow- larks and the redwing were reacting to something in the environment other than each other, but the relationship between them needs to be studied along with their specific habitat preferences. The state population of the meadow- larks in June, by our estimates, numbered 4,760,000 in 1909; in 1907, the popula- tion may have been as low as 3,200,000. The estimates for both 1957 and 1958 were 3,800,000. The size of the state population may not have changed greatly between census periods, but the distribu- tion of the population changed consider- ably. In June, 1909, there were only about 680,000 meadowlarks in the north- ern zone of the state, in contrast to 1,100,- 000 in both 1957 and 1958. The southern zone had about 2,000,000 in 1907, 3,100,- 000 in 1909, 1,900,000 in 1957, and 1,- 600,000 in 1958. The data suggest that the northern population of meadowlarks increased and that the southern population may have declined somewhat. By winter in all census years, the mead- owlark population had shifted southward, and the bulk of the state population was in the southern zone. Favorite winter habitats of the meadowlarks were hand- Inuinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 picked (cornstalk) cornfields (1906-07 only), hayfields of various types, small grain stubble, and mechanically picked cornfields (1956-1958 only). In 1906-07 particularly, the northern and the central zones of Illinois had al- most negligible wintering populations of meadowlarks (probably fewer than 10,- 000). In the recent census years, mead- owlarks wintered farther north in larger numbers; in January, 1957, there were _ probably about 300,000 in the northern and central zones combined. By our esti- mates, the southern zone had January populations of about 3,100,000 meadow- larks in 1907 and 3,400,000 in 1957. Like a number of other species, in late winter the meadowlarks probably move farther to the south before they move north to their breeding grounds. In February, 1958, the central and northern zones prob- ably had fewer than 10,000 meadowlarks, and the population in the southern zone was down to 1,400,000 birds, concen- trated primarily in hayfields that pro- vided good cover. Redwinged Blackbird.—Few species have undergone a more spectacular popu- lation increase since the turn of the cen- tury than the redwinged blackbird. The redwing was common even in 1907-1909, and the species was recorded throughout the state in all census years. In summer, densities of redwing populations varied from zone to zone and in most habitats were highest in the northern zone (all census years). In 1957-1958, densities in mixed hay decreased from north to south (northern zone: 198.7 redwings per 100 acres; central: 87.4; southern: 53.1). The redwinged blackbird was observed in a variety of summer habitats (all census years) including marshes, drainage ditches, all types of hay crops, all types of grass- land, fallow fields, oats, wheat, corn, soy- beans, plowed ground, shrubbery of all types, orchards, and forest; marsh, edge shrub, sweet clover, and mixed hay were notable favorites. “The redwing was pri- marily a marsh species originally; even in 1957-1958, population densities were higher in marshland than in any other major habitat. Long before the first sur- veys, marshland was a disappearing habi- tat in Illinois, and the redwing in this state has made greater and greater use of October, 1963 = Graper & GRABER: cultivated lands. Between 1907-1909 and 1957-1958, while marshland acreage in Illinois dwindled from about 600,000 acres to 60,000, population densities of the redwing in mixed hay increased from about 1+ per 100 acres to over 130. Summer population densities of the red- wing in important habitats of the state in 1957-1958 were 300.8 in marshes (309.8 in 1907-1909), 341.7 in edge shrubs, 203.6 in sweet clover, 158.0 along drain- age ditches, 134.3 in mixed hay (14.1 in 1907-1909), 88.5 in red clover (16.1 in 1907-1909), 64.5 in oat fields (3.9 in 1907-1909), 63.7 in ungrazed grasslands (47.6 in 1907-1909) , 57.8 in alfalfa, 30.1 in wheat (6.5 in 1907-1909), 26.5 in fal- low fields (3.3 in 1907-1909), 23.5 in pastureland (6.0 in 1907-1909), 23.0 in shrub-grown areas, +.6 in cornfields (1.6 in 1907-1909), and 3.3 in soybeans. In June, 1909, there were, by our esti- mate, about 5,100,000 redwinged black- birds in the state; the 1907 population may have been as low as 4,000,000. In June, 1957, the state population numbered about 8,400,000 and, in June of the fol- lowing year, over 11,000,000. In 1907- 1909, the distribution of the state redwing population followed the distribution of marshland (high in the northern zone, low in the scuthern zone) ; marsh habitat accounted for about 60 per cent of the state population. In 1909, in the southern zone, where marshes were least abundant, the redwing population (about 700,000 birds, in contrast to 2,400,000 in the northern zone) was already largely in cul- tivated habitats. In 1957-1958, marshes accounted for less than 3 per cent of the state redwing population, and the species had become more uniformly distributed in the state. The redwing is an example of a species that has adapted to a changing environ- ment. While hayfield populations of the redwing have not attained such high den- sities as marsh populations, the hayfields in recent years accounted for most of the state population. Although hayfields are the most important nesting habitats, the great increase of redwings in oat and wheat fields should be noted. Small grain fields have been only marginal nesting habitats, but they are probably important foraging habitats. Redwing populations in Birp PopULATIONS IN ILLINOIS 49| the state are probably still expanding, and efforts to control “blackbirds” because of their depredations on grain are expected to increase. The redwinged blackbird was not re- corded anywhere in the state in the winter survey of 1906-07. In the recent census years, the winter redwing populations in the northern and central zones of Illinois were all but negligible (fewer than 10,- Q00 birds) ; in the southern zone, the spe- cles was common but it was spottily dis- tributed. Favored winter habitats were cornfields, shrubbery of all types, and pas- ture. In January, 1957, we estimated, there were about 5,200,000 redwings in the southern zone. This great increase in the wintering population reflected the gen- eral increase, already noted, and probably also a tendency in the species (as noted in other species) to extend its winter range northward. The great disparity in red- wing numbers between the southern zone and the central and northern zones im- plies that the winter range of the red- winged blackbird cannot expand much north of 39 degrees latitude without a change in climate. Orchard Oriole.—The orchard oriole was found throughout the state in summer (all census years), but it was sighted four times as frequently in the southern as in the central zone and was least common in the northern zone. During the course of the censuses, this species was found in pas- tureland, fallow fields, mixed hay, red clo- ver, wheat fields, cornfields, and forest, besides the favorite habitats: orchards, shrubbery of all types, and (in 1907- 1909) residential areas. Because the 1907-1909 samples of woody habitats for the northern and central zones were par- ticularly small, we placed emphasis on data from the southern zone in considering pop- ulation changes in this species. Densities of orchard oriole populations in various habitats in the southern zone in 1907-1909 were 42.0 birds per 100 acres in orchards (1.3 in 1957-1958), 18.1 in residential areas, 10.0 in shrub- grown areas (7.1 in 1957-1958), 3.6 in pastures (2.5 in 1957-1958), 2.8 in fal- low fields (0.4 in 1957-1958), and 1.5 in mixed hay. Hedgerows and edge shrubs, for which we have no 1907-1909 data, were probably the best orchard oriole hab- 492 itats in 1957-1958, with densities of about 20 orioles per 100 acres in the southern zone. In 1957-1958, red clover (3.5 ori- oles per 100 acres) was a favored foraging habitat in the southern zone. Orchard oriole populations were proba- bly never very great in the northern or central zones. In those zones, by our esti- mate, there were at least 50,000 orchard orioles in marginal (nonwoody) habitats in June, 1909, but less than 25,000 in all habitats in 1957 and 1958. June popula- tions of orchard orioles in the southern zone numbered about 375,000 birds in 1907, 415,000 in 1909, 97,000 in 1957, and 65,000 in 1958. Habitat changes, the great losses in orchard acreage particu- larly, had much to do with the decline in the oriole population, but other factors than acreage changes must have been in- volved in the population decline. he or- chard oriole was apparently much more common in residential areas in 1907-1909 than in recent years. Also, oriole popula- tion densities in orchards declined greatly between 1909 and 1957. Some qualita- tive characteristics of these prime oriole habitats must have changed, and_ these changes, in turn, had a serious effect on the oriole population. The changing or- chard oriole population is another of the ornithological problems that need further study. Common Grackle.—During the course of the censuses (all years), the grackle was encountered commonly in summer throughout the state but only once in the winter season (southern zone). Population densities (all census years) in most habitats were highest in the northern zone, lowest in the southern. In marshes, for example, densities in both 1907-1909 and 1957-1958 were about 130 grackles per 100 acres in the northern zone but only 11 per 100 acres in the southern. Favorite summer habitats were edge shrubs and hedgerows, marshes, and _resi- dential areas, but grackles were found in all of the habitats censused. Densities of grackle populations in various summer habitats of the state in 1957-1958 were 268.5 birds per 100 acres in edge shrubs, 225.2 in hedgerows, 158.0 in drainage ditches, 97.7 in marshes (56.8 in 1907— 1909), 58.7 in residential areas (18.4 in Intinots NaruraAt History SurvEY BULLETIN Vol. 28, Art. 3 1907-1909), 33.7 in orchards (27.0 in 1907-1909), 25.6 in ungrazed grasslands (5.3 in 1907-1909), 19.3 in mowed hay, 17.9 in sweet clover, 16.5 in red clover (37.1 in 1907-1909), 15.2 in fallow fields (5.4 in 1907-1909), 12.8 in pastureland (13.2 in 1907-1909), 12.3 in mixed hay (6.0 in 1907-1909), 10.6 in forest (10.2 in 1907-1909), 7.4 in wheat (5.3 in 1907-1909), 6.6 in corn (7.7 in 1907- 1909), 6.2 in shrub-grown areas (1.8 in 1907-1909), 5.7 in oats (7.1 in 1907- 1909), 4.8 in soybeans, and 2.6 in alfalfa. In most habitats, the recent trend was to- ward increased population densities. The orchard populations are of interest, be- cause the grackle is one of the very few species that had orchard populations as dense in 1957-1958 as in 1907-1909. Despite the high population densities of the grackle in certain habitats in recent years, the state population of grackles de- clined slightly between 1909 and 1957, possibly because of habitat changes, par- ticularly loss of marsh and orchard acre- age. We estimated that June populations of grackles in the state were about 4,100,- 000 in 1909 (probably about the same in 1907), 3,600,000 in 1957, and 3,500,000 in 1958. The grackle population of Illi- nois changed in distribution between the two periods. In 1907-1909, grackles were concentrated especially in the northern zone (41 per cent of the state population ) and the central zone (37 per cent) but, in recent census years, the central zone had only about 15 per cent of the state popula- tion. The cause of this regional change is not apparent. The increase in urban acre- age should tend to swell the grackle popu- lation, particularly in northern Illinois, where the population density is highest. Brown-Headed Cowbird.—In all census years, the brown-headed cowbird was found throughout the state in sum- mer, but only in recent years and in the southern zone was it found in the winter season. Summer cowbird populations tended (all census years) to be most dense in the northern zone. In 1907-1909, the southern zone had the lowest population densities, but, in the recent census years, the central zone had the lowest densities. The cowbird was encountered in virtu- ally all of the summer habitats. Densities were highest in edge shrubs, hedgerows, October, 1963) = Graner & GRABER: and shrub-grown areas, which are proba- bly the principal habitats of the cowbird hosts, but the cowbird appeared to have less marked habitat preferences than most species of Illinois birds. Densities of cow- bird populations in various I]linois habitats in 1957-1958 were 55.5 birds per 100 acres in edge shrubs, 30.0 in hedgerows, 17.8 in shrub-grown areas (14.2 in 1907— 1909), 7.8 in forest (6.4 in 1907-1909), 7.5 in marsh, 5.4 in pastureland (8.3 in 1907-1909), 5.1 in ungrazed grassland, 2.9 in fallow fields (2.7 in 1907-1909), 2.7 in mixed hay (1.6 in 1907-1909), 2.5 in orchards, 2.1 in red clover (2.5 in 1907-1909), 1.8 in corn (1.7 in 1907— 1909) and sweet clover, 1.3 in alfalfa, 0.9 in wheat (1.3 in 1907-1909), and 0.3 in oats (1.6 in 1907-1909). Year-to-year variation in the cowbird population was particularly high, but we judge that the state population declined between 1909 and 1957. In nonwoody habitats in June, 1909, the state popula- tion numbered about 1,800,000 cowbirds. The 1907 population in nonwoody habi- tats was probably about half as great (esti- mated from populations in the central and southern zones). In the recent census years, woody habitats accounted for most of the state cowbird populations, esti- mated to number about 1,130,000 in 1957 and 920,000 in 1958. To some extent, the decline of pastureland acreage may have hurt the cowbird, particularly in the northern and central zones. Pastures were probably important to the cowbird, both as foraging and “nesting” habitats; northern zone densities in this habitat were about 23 cowbirds per 100 acres in 1907-1909 and only 5 in 1957-1958). Despite the large summer populations in the early census years and the mildness of the 1906-07 winter, no wintering cowbirds were reported in the early sur- vey. About 350,000 cowbirds (most of them in shrub areas and small grain stub- ble) were found in the southern zone in January, 1957, but none in February, 1958. Like a number of other species, the cowbird may be wintering farther north now than in earlier years. Cardinal.—In the recent census years, the cardinal was recorded throughout the state, both in summer and winter. Perhaps because of the small samples of woody Birp PopuLaATioNs IN ILLINOIS 493 habitats censused, it was not recorded in northern Illinois in 1906-1909. The car- dinal has greatly extended its range north- ward since the turn of the century. In the later census years, the summer popu- lation thinned progressively north of the southern zone. For example, recent car- dinal populations in Illinois forests in summer were about 23 birds per 100 acres in the southern zone but only 10 in the northern. The cardinal was found during the summer surveys in marsh, fallow fields, ungrazed grassland, pastures, mixed hay and alfalfa fields, wheat, and corn, as well as in the favored woody habitats. Population densities in various habitats of the southern zone in 1957-1958 were 160.0 cardinals per 100 acres in edge shrubs, 22.8 in forest (23.4 in 1907- 1909), 20.6 in orchards (13.3 in 1907— 1909), 15.8 in shrub-grown areas (36.1 in 1907-1909), and 9.2 in residential areas. Small samples of hedgerow acreage in I]li- nois had populations averaging about 240 cardinals per 100 acres in 1957-1958. ‘The cardinal population in the state in- creased between 1909 and 1957 largely be- cause of range extension, but also because of increased acreage of the favored woody habitats. In June, 1909, in all habitats (including woody habitats), there were about 650,000 cardinals in the southern zone; in June, 1907, there were about 400,000. In 1957 and 1958, southern zone populations were, respectively, about 780,000 and 980,000. The southern zone then had about 70 per cent of the state- wide cardinal population, which numbered about 1,200,000 birds in 1957 and 1,300,- 000 in 1958. Only about 8 per cent (100,000 birds) of this total was in north- ern Illinois. We could not estimate the northern and central zone populations of cardinals for 1907-1909, because of the small samples of woody habitats censused. A forest sample in central Illinois in 1907-1909 indicated a population of about 19 cardinals per 100 acres, in contrast to 31 per 100 acres in 1957-1958. Cardi- nals were found in central zone pasture- land in 1957-1958, but not in 1907-1909. It is clear that the northern and central zone populations of cardinals increased greatly between 1909 and 1957. The acreage of woody habitat in the 494 cardinal’s range increased between 1909 and 1957, but the summer population density in southern Illinois forests re- mained about the same. This situation suggests that the cardinal population in southern Illinois was about at the satura- tion point in 1907-1909 and remained so, keeping pace with the expanding habitat. Our data for central Illinois, though lim- ited, suggest that the central zone habitats of cardinals were not saturated in 1907- 1909, but that they were in 1957-1958; in the second census period, densities re- corded for the central zone were even higher than those for the southern zone. The northern zone, apparently, had vir- tually no cardinal population in 1907- 1909, and, even in 1957-1958, the habitats in the northern zone were far from sat- urated. In the coming decades, the car- dinal population should continue to in- crease. Residential habitat is not so good for the cardinal as the natural types, but urbanization, as long as it encroaches on cultivated lands and not on forest, will benefit the cardinal. Winter distribution of the cardinal fol- lowed the summer pattern (highest popu- lation in the southern zone, lowest in the northern) ; the surveys showed there was some tendency for the cardinal to visit open-field habitats more in winter than in summer. The cardinal is supposedly not migra- tory, but our data suggest that there may be a southward shift of the population in midwinter. In January, 1957, the entire state had an estimated population of about 2,000,000 cardinals (1.6 times the June population), of which 1,700,000 were in the southern zone. ‘The number of cardi- nals in northern and central Illinois in January seemed to fall below the June level; the southern zone population in January was about 2.1 times its June level, in both 1907 and 1957. This hy- pothesized “migration” of the cardinal presents a problem that needs investiga- tion through banding. Indigo Bunting.—In all census years, the indigo bunting was found throughout the state in summer. The bunting popula- tion was most dense in the southern zone and decreased progressively northward. In Illinois forests, for example, population densities were about 17 buntings per 100 Inninots NarurAL History SurvEyY BULLETIN Vol. 28, Art. 3 acres in the southern zone, 8 in the central zone, and + in the northern. In the course of the surveys, the indigo bunting was counted in virtually every habitat; woody types were the most im- portant habitats. Densities of bunting populations in various summer habitats of the southern zone in 1957-1958 were 295.0 birds per 100 acres in edge shrubs, 234.5 along drainage ditches, 228.3 in hedgerows, 39.9 in shrub-grown areas (42.2 in 1907-1909), 17.5 in forests (28.4 in 1907-1909), 12.9 in orchards (11.0 in 1907-1909), 8.7 in wheat fields (1.7 in 1907-1909), 7.4 in fallow fields (0.9 in 1907-1909), 6.8 in ungrazed grasslands, and 4.1 in pastures .(0.3 in 1907-1909). The apparent increased im- portance of wheat fields as foraging habi- tat for this species in recent years is wor- thy of note. The number of indigo buntings in IIli- nois probably increased at least slightly between 1909 and 1957. Population den- sities apparently did not change greatly in any zone, but the acreage of prime woody habitats for buntings increased in the southern zone and (slightly) in the cen- tral zone, the zones with the highest bunt- ing populations. We estimated that June populations of indigo buntings in the southern zone numbered (in all habitats but edge shrub) about 850,000 birds in both 1907 and 1909 and (in all habitats) 1,400,000 in 1957 and 1,100,000 in 1958. We could not estimate summer popula- tions in the northern and central zones for 1907 and 1909, because of the paucity of data on woody habitats, but our informa- tion on other habitats indicates that the bunting population of the state was higher in 1957-1958 than in 1907-1909. We estimated that the entire state had about 1,700,000 indigo buntings in 1957 and 1,400,000 in 1958. About 80 per cent of the state population of indigo buntings was in the southern zone, 15 per cent in the central, and 5 per cent in the north- ern. Because densities of indigo bunting populations were about the same in all census summers, we do not expect great population expansion in this species, but some increase should occur if the acreage of woody habitats continues to increase. The bunting was probably not abundant October, 1963 Graper & GRABER: in the primeval Illinois habitats of forest and prairie, and the original cutting of timber, because this cutting increased forest-edge and shrub habitat, probably favored the species. Dickcissel.—One of the most abun- dant fringillids in Illinois, the dickcissel, was found (all census years) throughout the state in summer. Densities of dickcis- sel summer populations were consistently (all years and most habitats) highest in the central zone, lowest in the northern. Representative of this regional variation were recent densities of dickcissels in red clover fields: about 20 birds per 100 acres in the northern zone, 78 in the central, and 34 in the southern. Favorite dickcissel habitats in summer were hayfields of all types, small grain and grassland habitats, edge shrubs, and hedge- rows; dickcissels were found also in corn- fields, soybean fields, plowed fields, or- chards, and shrub-grown areas. Population densities of the dickcissel in various summer habitats in central I]linois in 1957-1958 were 220.9 birds per 100 acres in edge shrubs, 163.5 in hedgerows, 115.8 in sweet clover, 93.4 in mixed hay (33.4 in 1907-1909), 77.9 in red clover (55.6 in 1907-1909), 80.6 in ungrazed grassland, 79.2 in fallow fields, 64.5 along drainage ditches, 28.8 in alfalfa, 22.3 in wheat fields (7.1 in 1907-1909), 17.8 in oats (6.8 in 1907-1909), and 8.2 in pas- tures (3.4 in 1907-1909). Why popula- tions of the dickcissel were consistently much lower in alfalfa than in other types of hay is unknown; alfalfa was also the least preferred hay type for the redwinged blackbird. The dickcissel and the redwing show some similarity in the placement of their nests. Despite high variability in dickcissel numbers from year to year, it is clear that the population increased greatly between 1909 and 1957. In June, 1909, there were estimated to be 1,700,000 dickcissels in the state; the 1907 population was lower (probably about 1,500,000). In 1957 and 1958, the central zone had, by our esti- mate, about 2,250,000 dickcissels; the state population numbered about 3,350,- 000 birds in 1957 and 3,850,000 in 1958. Populations in the northern zone (only 2 to 6 per cent of the state total) and in the southern zone (30 to 40 per cent) Birp PopuLATIONS IN ILLINOIS 495 were much more variable than those in the central zone. The dickcissel is another species that has adapted well to cultivated habitats that replaced the original prairie. In 1957-1958, dickcissel densities were higher in fields of tame hay (as a group) than in the ungrazed prairie-like situations; total hay acreage increased between the two census periods. Even at the time of the early surveys, the dickcissel population was probably on the increase. American Goldfinch.—In both sum- mer and winter, the American goldfinch was recorded throughout the state. In all census years, populations tended to be most dense in the northern zone. In shrub- grown areas, for example, in the summers of 1957-1958, there were about 46 gold- finches per 100 acres in the northern zone of Illinois, 33 in the central zone, and 5 in the southern. Vhe goldfinch was found in nearly ev- ery summer habitat censused; shrubbery of all kinds, orchards, and ungrazed grass- lands were particularly favored. Summer densities of goldfinch populations in vari- ous habitats in the northern zone in 1957— 1958 were 167.5 birds per 100 acres in edge shrubs, 96.2 in orchards, 69.9 in un- grazed grassland, 46.4 in shrub-grown areas (29.1 in 1909), 7.3 in forest, 6.4 in pastures (2.1 in 1907-1909), 6.1 in oat fields (2.1 in 1909), and 4.3 in marshland. Because of the paucity of data on woody habitats in central and northern Illinois for 1907-1909, there is little basis on which to speculate about population changes in this species. Southern Illinois summer populations, at least, were rough- ly comparable in 1907 and 1958 (about 500,000 birds in each year). For the en- tire state, we estimated, the June popula- tions of goldfinches numbered about 880,- 000 birds in 1957 and 1,000,000 in 1958. While population densities were consist- ently highest in the north, the southern zone had most of the good goldfinch habi- tat of the state, and therefore a high per- centage (as much as 47 per cent in 1958) of the state population. In winter, highest populations of the goldfinch occurred in forests, shrubs of all types, in pastureland, fallow fields, and ungrazed grassland, and (in 1906-07 ) cornstalk habitat. No species in Illinois 496 showed more erratic fluctuations in popu- lation than the goldfinch; the winter dis- tribution was particularly erratic. In the mild winter of 1906-07, there were, by our estimate, at least 1,600,000 gold- finches (January, 1907, population) in Illinois, most (about 90 per cent) of them in the northern and central zones. In Jan- uary, 1957, the state population was the same as in June of that year, or about 900,000 birds, most (about 80 per cent) of them in the southern zone. Savannah Sparrow.—lIn summer of both census periods, the savannah sparrow was encountered in the northern and cen- tral zones of Illinois. However, the popu- lation in the central zone in recent census years was sparse. The savannah sparrow in summer was found in grassland habitats of all types, marsh, all hay crops, oat fields, and soy- bean fields; populations were highest (all census years) in pastures and ungrazed grassland. Population densities of the sa- vannah sparrow in various habitats in northern Illinois 1957-1958 were 38.5 birds per 100 acres in mowed hay, 27.8 in shrub-grown areas, 23.5 in ungrazed grassland, 20.8 in pastures (5.7 in 1909), 13.6 in red clover, 13.0 in mixed hay (1.7 in 1909), 4.3 in alfalfa, 3.9 in sweet clo- ver, 2.8 in marsh (5.2 in 1909), and 2.1 in fallow fields (16.5 in 1909). Alfalfa and sweet clover proved to be relatively poor habitats for this ground-nesting spe- cies. “The meadow-like marshes that were more numerous in the early survey years than later may have been a fairly im- portant habitat for the savannah sparrow. The savannah sparrow population in the state probably increased somewhat be- tween 1909 and 1957 despite a loss in pas- ture acreage. In June, 1909, there were, we estimated, 160,000 savannah sparrows in the state (about 20,000 in the central zone). In both 1957 and 1958, the June population numbered about 390,000 birds, most in the northern zone. The savannah sparrow greatly increased its population in hay habitats; there was a general increase in population density that may have had no relationship to habitat acreage changes. In winter, the savannah sparrow was recorded only in the recent census years and in southern Illinois, where the popu- lation was all but negligible. Intinoris NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 Grasshopper Sparrow.—In all cen- sus years, the grasshopper sparrow was en- countered in summer throughout the state; population densities were consistently highest in the central zone and lowest in the southern. In red clover fields, there were about + grasshopper sparrows per 100 acres in the northern zone, 9 in the central, and only 2 in the southern. In summer, the grasshopper sparrow oc- curred in all grassland and hay habitats, oat and wheat fields, soybean fields, corn- fields, orchards, and shrub areas. Densi- ties of grasshopper sparrow populations in the most favored summer habitats in cen- tral Illinois in 1957-1958 were 53.2 birds per 100 acres in sand prairie, 42.5 in mixed hay (16.7 in 1907-1909), 40.9 in alfalfa, 9.3 in pastures (3.4 in 1907-1909), and 8.9 in red clover (19.2 in 1907-1909). Populations of the grasshopper sparrow in fields of small grain changed between 1909 and 1957. In oat fields of the central zone, there were virtually no grasshopper sparrows in 1957-1958 (2.8 per 100 acres in 1907-1909) ; in wheat fields of this zone there were 1.6 grasshopper spar- rows per 100 acres in 1957-1958 (1.1 in 1907-1909). Alfalfa, a relatively poor habitat for the savannah sparrow and a number of other grassland species, proved to be a high-density habitat for the grass- hopper sparrow. The grasshopper sparrow is a small spe- cies, and, except for the singing male, in- conspicuous; in all likelihood, our density figures and population estimates are well below the true figures, but suitable for comparison within the study. Our data indicate that the grasshopper sparrow pop- ulation did not change greatly between the two census periods. In June, 1909, we estimated, there were about 500,000 grasshopper sparrows in Illinois. The 1907 population was higher, probably ex- ceeding 700,000 birds. June populations in 1957 and 1958 numbered, respectively, about 700,000 and 850,000 birds. In all years, the central zone had over 50 per cent of the state population; this latitud- inal distribution was particularly marked in 1957-1958, when about 70-80 per cent of the Illinois grasshopper sparrows were in the central zone. The future for this species appears to be reasonably bright. Pasture acreage in Illinois continues to October, 1963 Graper & GRABER: decline, but hayfields offer a good reservoir habitat. Vesper Sparrow.—lIn all of the sum- mer censuses, the vesper sparrow was found in the northern and central zones and, in 1957, also in the southern zone. About 90 per cent of the state population was in the northern zone. The vesper sparrow was recorded in summer in all grassland and hay habitats, fallow fields, small grain, soybeans, corn, plowed fields, shrubbery of all types, and orchards; edge shrubs, red clover fields, and shrub-grown areas were particularly favored by this species. Population densi- ties of vesper sparrow populations in vari- ous habitats of the northern zone in 1957— 1958 were 58.6 birds per 100 acres in edge shrub, 14.5 in red clover (8.9 in 1909), 12.4 in shrub-grown areas, 9.4 in ungrazed grassland, 8.8 in mowed hay- fields, 5.8 in alfalfa, 5.7 in pastures (2.6 in 1909), 3.4 in corn (4.7 in 1909), and 2.9 in mixed hay (2.8 in 1909). The preference of the vesper sparrow for red clover was further indicated by the fact that, in the southern zone (the southern edge of the nesting range for this species), this sparrow was found only in red clover. The vesper sparrow, unlike most of the fringillids, occurred with fairly high fre- quency in bare-field habitats, the row crops and plowed fields. Neither the state population of the ves- per sparrow nor its distribution changed greatly between 1909 and 1957. In June, 1909, there were about 250,000 vesper sparrows in Illinois; the state population numbered about 390,000 in 1957 but only about 150,000 in 1958. The population of the southern zone probably did not ex- ceed 10,000 birds in any year. Habitat changes between the two census periods should not have affected the vesper spar- row to any great extent; although the pasture acreage decreased, there was more red clover in 1957-1958 than in 1907-— 1909. Because the vesper sparrow nests in a greater variety of habitats than most of the open-field fringillids, and because it seems to favor even the bare-field habi- tats, it is surprising that this species did not show some gain in population. Other factors than habitat availability may have been responsible for holding the popula- tion at a low level. Bird POPULATIONS IN ILLINOIS 497 Lark Sparrow.—In 1907-1909, the lark sparrow was found in all zones, but between 75 and 95 per cent of the state population was in the southern zone. By contrast, in 1957-1958, we recorded lark sparrows only in the central (about 90 per cent of the state population) and in the northern zone. To a large extent, the distribution of the lark sparrow is proba- bly governed by the local distribution of sandy and other poor soils. In the recent surveys, we covered enough ground to be reasonably certain that the lark sparrow population in 1957-1958 in the southern zone was almost negligible by comparison with the 1907-1909 population in that zone. Unlike virtually all of the other spe- cies censused, the lark sparrow showed no very decided habitat preference, perhaps partly because the soil requirement noted above overrides the vegetation require- ment and partly because this sparrow nests in a broad variety of habitats, both on the ground and in trees. Population densities of the lark sparrow in various summer habitats in the southern zone for 1907-1909 were 4.1 birds per 100 acres in pastures, 2.5 in fallow fields, 2.2 in cornfields, 2.0 in wheat, and 1.6 in oats. Densities in various habitats (sandy and poor soil areas only) in central Illinois in 1957-1958 were 25.2 lark sparrows per 100 acres in hedgerows, 14.3 in plowed fields, 5.5 in fallow fields, 2.0 in shrub- grown areas, and 1.2 in pastures. In June, 1909, by our estimate, there were about 500,000 lark sparrows in Illi- nois, of which 370,000 were in the south- ern zone. The 1907 population was lower, but it exceeded 300,000 birds. Summer populations numbered about 80,000 birds in 1957 and 70,000 in 1958, most of which were in the central zone. The lark sparrow is a versatile species in its nest- ing habits, and it is difficult to understand why the population declined so much; the great loss in southern Illinois is particu- larly puzzling. Here we can only point out the need for a detailed study of the biology of the lark sparrow in [Ilinois. Slate-Colored Junco.—In both sur- vey periods, the slate-colored junco was recorded in winter throughout Illinois, but about 90 per cent of the state popula- tion (all census years) was in the south- 498 ern zone; the numbers fell off sharply to the north. The junco was found in all of the winter habitats; edge shrubs, hedge- rows, shrub-grown areas, and (in 1906— 07) orchards had particularly high densi- ties. Of the open-field habitats, fallow fields, ungrazed grasslands, cornfields of all types, and pastures were conspicuous favorites of the junco. January populations of the junco in IIli- nois numbered, by our estimates, about 5,300,000 birds (4,400,000 in the south- ern zone) in 1907 (very mild weather) and 6,400,000 (5,900,000 in the southern zone) in 1957. The January population of 1957 was higher in most habitats than that of 1907; the 1957 population in the northern zone especially was high, about six times the 1907 level. These data fit a pattern observable in a number of other species—a trend toward higher winter populations at latitudes farther north in recent years. Published Christmas count records for central Illinois (Anon. 1900- 1960) indicate that winter junco popula- tions were neither unusually high nor low in 1906-07, 1956-57, and 1957-58. In February, 1958, the state population ex- ceeded 10,000,000 juncos, and, because in the central zone the population was then almost four times the population in Janu- ary, it was evident that northward migra- tion was in progress, despite the severe weather conditions that prevailed. ‘The high population of juncos in Illinois in February must have included a large num- ber of migrants from wintering grounds south of Illinois. Tree Sparrow.—In all census win- ters, the tree sparrow was found through- out Illinois. Unlike the junco, the tree sparrow was uniformly distributed in the state. The tree sparrow occurred in virtually all of the winter habitats censused; like the junco, this sparrow especially favored edge shrubs and hedgerows, shrub areas, and, among open-field habitats, fallow fields and corn stubble. In 1906-07, the tree sparrow was much more abundant in corn stubble than in picked corn (corn- stalk) fields; the latter habitat was pre- ferred by most species of winter residents. Examination of Illinois Christmas count data (Anon. 1900-1960) showed that the tree sparrow population was more Intinoris NarurAv History SuRVEY BULLETIN Vol. 28, Art. 3 highly variable than the junco population and that the number of tree sparrows win- tering in Illinois was not unusual in 1906— 07 or in 1957-58, but was abnormally high in 1956-57. The strip census data fit well with this picture. We estimated that January populations of the tree spar- row in Illinois numbered about 1,600,000 in 1907 and 6,900,000 in 1957. The Feb- ruary population in 1958 was about 2,- 000,000 birds, and there was no indication of northward migration within the state, though many migrants could already have moved north of Illinois. Chipping Sparrow.—In 1907-1909, the chipping sparrow was found through- out Illinois in summer; in the later survey period, this species was not recorded in central Illinois, and the population in the other zones was vestigial. Even during the early surveys, the chipping sparrow population was highly variable from zone to zone and from year to year; the south- ern zone had the highest population. In 1957-1958, most of the Illinois chipping sparrows were in the northern zone. Favorite summer habitats of the chip- ping sparrow were residential areas, or- chards, and pastures; in 1907-1909, the chipping sparrow was found in a variety of woody and open-field habitats. In the half century between survey periods, chip- ping sparrows were probably not very abundant in Illinois, but the June popu- lation numbered, by our estimates, about 250,000 birds in 1909 (probably almost as many in 1907) and less than 50,000 in 1957 and 1958. Habitat acreage changes may have had little to do with the decline. Loss of orchards would seem to have been detrimental to the chipping sparrow. An- other favorite habitat, residential areas, increased in acreage with no apparent benefit to the species. Field Sparrow.—In all census years, the field sparrow was found throughout the state in summer and in the southern zone.in winter. Summer populations tended to be most dense in the southern and central zones, the zones that had the bulk of the optimum habitat; in all years, most of the state population was in the southern zone. Favorite summer habitats for the field sparrow were shrubs of all types, hedge- rows, orchards, and pastures. Densities of : October, 1963 Graper & GRABER: field sparrow populations in various habi- tats in the southern zone in 1957-1958 were 200.0 per 100 acres in edge shrubs, 91.3 in hedgerows, 53.4 along drainage ditches, 37.4 in shrub-grown areas (46.9 in 1907-1909), 23.1 in orchards (59.7 in 1907-1909), 19.9 in pastures (8.6 in 1907-1909), 11.7 in fallow fields (8.8 in 1907-1909), 10.2 in ungrazed grasslands, 4.7 in forest (28.4 in 1907-1909), 4.4 in wheat (3.5 in 1907-1909), and 1.5 in hayfields of all types (3.0 in 1907-1909). Although many of the density figures indi- cated higher populations for the early than for the later census years, the density in pastureland, a declining habitat, was nota- bly higher for 1957-1958 than for 1907— 1909. In June, 1909, the state population of field sparrows numbered, by our estimate, at least 2,100,000 birds (75 per cent in the southern zone); the 1907 population was lower but probably exceeded 1,700,- 000 (these estimates do not include edge shrub or hedge populations). June popu- lations in 1957 and 1958 were, respec- tively, about 1,400,000 and 1,000,000 birds (62 per cent in the southern zone, both years). Habitat acreage changes probably had some effect on the field sparrow popula- tion. In the summers of 1907 and 1909, southern Illinois orchards alone accounted for over 100,000 birds, in contrast to 15,- 000 or less in 1957-1958. This change represents both an acreage loss and a loss in population density of the field sparrow in orchards. Though several insectivorous and frugivorous species showed density re- ductions in orchards between 1909 and 1957, the field sparrow is one of the few fringillids that declined in orchard habi- tat. The increase in forest and shrub acre- age between 1909 and 1957 would have helped the field sparrow population if pop- ulation density had kept pace with the acreage increase in these favorable habi- tats. Winter habitats for the field sparrow were the winter counterparts of the sum- mer habitats in southern Illinois. The winter population of the field sparrow in Illinois has probably never been very large. We estimated January populations of this sparrow to be about 85,000 birds in 1907 Birp PoPpULATIONS IN ILLINOIS 499 and 190,000 in 1957. The population in February, 1958, was almost negligible (about 10,000 birds), and there was no indication of northward migration. Field sparrows, like birds of a number of other species, probably drifted farther south- ward in late winter. Song Sparrow. — In the recent sur- veys, the song sparrow was found through- out Illinois in both summer and winter. In 1907-1909, the species was widely dis- tributed in winter, but it did not occur in the southern zone in summer. In all census summers, the song sparrow popula- tion was most dense in the northern zone. In shrub areas, the northern zone had about 37 song sparrows per 100 acres, while the central zone had only 8 per 100 acres; the southern zone had only a negli- gible population. Densities of song spar- row populations in various habitats in the northern zone in the summers of 1957- 1958 were 95.9 birds per 100 acres in edge shrubs, 62.9 in hedgerows, 37.1 in shrub- grown areas, 32.0 along drainage ditches, 11.4 in marshes (5.2 in 1909), 11.0 in or- chards, 5.2 in ungrazed grasslands (20.3 in 1909), 3.9 in sweet clover, 3.2 in pas- tures, 2.7 in red clover, 1.7 in forest, and 1.4 in mixed hay (2.8 in 1909). Along with its range extension southward, the song sparrow population in Illinois prob- ably increased at least slightly between 1909 and 1957. By our estimate, June populations of the song sparrow in Illinois numbered about 180,000 birds in 1909, 250,000 in 1957, and 290,000 in 1958. At least 2,000,000 acres of Illinois land were not accounted for in these estimates, and this acreage—probably various mar- ginal habitats—may include a significant amount of prime song sparrow habitat. Thus, the actual state population may be much higher than our estimates for this species. Habitat acreage changes between the two census periods had only slight ef- fect on the song sparrow population. Loss of marshland, orchards, and pasture was largely balanced by increase in forest edge. In winter, though song sparrows oc- curred throughout Illinois (all census years), most of the state population was in the southern zone, where the winter population exceeded the summer popula- tion. Ungrazed grasslands, shrub habitats, marshes, and drainage ditches were espe- 500 cially preferred winter habitats of the song sparrow. By our estimates, January populations of song sparrows in Illinois numbered about 350,000 birds in 1907 (88 per cent in the southern zone) and 475,- 000 in 1957 (70 per cent in the southern zone). Like many other species, the song sparrow may be wintering farther north in greater numbers now than in earlier years. This sparrow may be more tolerant of cold than many other migratory fringil- lids. As many as 70,000 song sparrows wintered in the northern zone, and, un- like the birds of many of the species con- sidered in this report, song sparrows did not appear to move southward in late win- ter shortly before the onset of spring mi- gration. Our data indicate that, despite severe winter weather, song sparrows were migrating north in great numbers in February, 1958, when the southern popu- lation was swelled to about 900,000 birds, presumably by an influx of migrants from farther south. Lapland Longspur.—In the first win- ter survey (1906-07), the Lapland long- spur was found only in the northern zone of Illinois, but, in 1956—57, this species was abundant in both the northern and central zones; in 1957-58, it was recorded throughout the state. In recent census years, January population densities were highest in the central zone. Like the horned lark, the Lapland long- spur in winter particularly favored open habitats with relatively little cover; ap- parently some low cover was important in the habitat. In the central zone, popula- tion densities in recent census years were about 84 birds per 100 acres in cornfields, 51 in alfalfa, 42 in soybean stubble, and 28 in small grain stubble, but only 5 in plowed fields. In January, 1907, by our estimate, there were about 700,000 longspurs in Illinois, all in the northern zone. In Jan- uary, 1957, the state population numbered about 4,800,000 birds, most of them (86 per cent) in the central zone and none in the southern. Longspur populations are known to be extremely variable, and per- haps the great difference between the 1907 and 1957 populations falls within the range of “normal” year-to-year variation. Both winters were mild, at least until late Intinois NaTuRAL History SurvEY BULLETIN Vol. 28, Art. 3 January. In recent years (1956-1962), we have found the longspur to be common in central Illinois every winter, and it is possible that the species is extending its winter range southward, or perhaps east- ward. Habitat changes probably favored such an extension. Cornfields, which now make up a large part of the Lapland long- spur habitat in winter, were of little value to the longspur in earlier times when hand- harvesting methods left stalks standing; the cover was too dense and tall for this species. The initiation of mechanical har- vesting methods, which flatten stalks to the ground, and the beginning of soybean agriculture created millions of acres of prime winter habitat for the longspur in Illinois. In February, 1958, longspur distribu- tion in the state had a pattern not seen previously. In this time of extremely ad- verse weather conditions, longspurs (prob- ably about 5,700,000) occurred through- out the state, but in greatest numbers in the southern zone (about 3,200,000). Coincident with a great increase in the population of the southern zone, the num- ber of longspurs in central Illinois fell from the January level of 4,150,000 to about 1,900,000. Obviously, the popula- tion had shifted southward in late winter, but whether this is an annual occurrence remains to be determined. DISCUSSION Much of the world’s ornithological lit- erature deals expressly with variations in populations of wild birds, but still we know relatively little about rates of change in these populations. We know that, in time, even the species is transient; examining the fossil record (Wetmore 1940), we find no positive evidence that any North American bird species now extant has survived more than about 10,- 000,000 years. In less time—since the be- ginning of the Pleistocene, perhaps a mil- lion years ago—the number of species in the North American avifauna has prob- ably been reduced by about one-fourth. In much less time, many important faunal changes have become matters of historical record. In the Illinois avifauna alone (Smith & Parmalee 1955), we could note the disappearance, within the past 100 years, of at least a dozen species and the eS ae ee October, 1963 Graper & GRABER: establishment in numbers of half a dozen more. Looking back, we perceive faunal changes and acknowledge that they are continuing. The fauna that we study now is an ever-changing heritage from the past. Though in a broad sense evolution has no beginning and no end, it has directions that are affected by factors untold in number. The annual fluctuations that character- ize all bird populations make it particu- larly difficult to identify changes that have direction and relative permanence. Certain faunal changes (for example, range ex- tension by such conspicuous species as the cardinal and the mockingbird) are easily detected even in their early stages. Other faunal changes (for example, the decline leading to extinction of a species) may be noticed only in the later stages of the change. Some trends may be detected only in the light of periodic population meas- urements. The need for detailed censuses of birds was recognized long ago, but, despite the initiation of the Christmas counts in 1900 (Chapman 1900:192), two nationwide summer censuses sponsored by the United States Biological Survey (Cooke 1915, 1916), and subsequent development of a regular program for censusing breeding birds (Hickey 1937), there are still rela- tively few bird population data available for much of North America. Most re- corded population measurements of high quality are provincial in avifaunal, eco- logical, and geographical scope and span only relatively short periods of time. In- formation for habitats other than forest is particularly scarce, though the census program is expanding steadily through the voluntary efforts of many ornithologists. The value of systematic bird censuses increases as the years pass, for without some reference to the past we cannot see the trends of evolution ; we can see neither the magnitude nor the direction of change. In terms of quantitative data on bird pop- ulations in North America, we have few reference points before 1915. In view of the paucity of quantitative data, and the habitat changes that have occurred in the past half century, the efforts of Stephen A. Forbes and Alfred O. Gross to provide detailed information on the bird life of 1906-1909 in virtually every habitat in Birp PopuLaTions IN ILLINOIS 501 Illinois appear particularly farseeing and commendable. Almost inevitably, the field biologist, because he deals with many variables, be- comes uneasy about the adequacy of his data. In this paper, our interpretations are based on a record of only 4 years, 2 early in this century and 2 in midcentury. For many species of birds, the temporary fluctuation in population between two con- secutive census years might far exceed any irreversible directional change that would occur in a period of 50 years or more. Fully recognizing the possibility of con- fusing short-term fluctuations with rela- tively permanent changes, we have still accepted the differences between the 1906— 1909 and 1956-1958 data largely at face value. In our conclusions, we have been guided for the most part by the strip census records. The data presented in tables and text are always open to re- evaluation, and the reader should bear this fact in mind. Events Previous to 1800 Following the last glaciation—perhaps 10,000 years ago (Livesay 1951:23)— and before white settlement, there were probably few types of bird habitats in the area that was to become the state of [Ili- nois. In succession, the melting glaciers gave way to open lakes, to marshes, and then largely to drier habitats of grassland and forest. The present Illinois soil types indicate that in pre-Columbian times and as late as about 1800 approximately 14,- 000,000 acres were forested (King & Winters 1952:20) and between 21,000,- 000 and 22,000,000 acres were primarily prairie grassland. Included in these total acreages there were probably more than the 1,400,000 acres of wetlands reported by Shaw & Fredine (1956:5) for a later period. Naturally disturbed forest areas (areas disturbed by fire, flood, or erosion) undoubtedly gave rise to some shrub habi- tat, but the acreage of this habitat is in- estimable. Quantitatively, at least, the Illinois avi- fauna of 1800 and before is unknown. If we could assume bird population densities for 1800 similar to those of the early 1900’s for the acreages in the primary habitats of forest, marsh, and prairie, then in 1800 and probably many years before 502 the Illinois area would have had a breed- ing bird population of about 97,000,000 birds—53,000,000 in forest, 7,500,000 in marsh, and 37,000,000 on the prairie. In the years previous to 1800, man was a minor force in effecting faunal changes in the Illinois country. The Indian inhabi- tants of this area cultivated some land, probably only a few thousand acres. Mar- quette reported that the Illini tribes num- bered 8,000 or 9,000 persons in 1670 (Temple 1958:14). The Indian popula- tion of the area dwindled through the 18th century. Zebulon M. Pike reported that in 1805 the Sauks and Foxes, who had largely replaced the Illinois tribes, together numbered only about 4,600 per- sons (Temple 1958:99-101). These thin populations had probably transformed but little of the natural habitats of the area. Development of Managed Habitats White settlement of the Illinois coun- try, which began about 1700 (King & Winters 1952:10), was still negligible by 1800. In 1798, there were about 5,500 whites in the area that later formed the states of Illinois, Indiana, Wisconsin, and Michigan (Hagan 1958:3). In the fol- lowing century, the 19th, most of the Illi- nois lands came under cultivation. In that century, perhaps as many as 10,000,000 acres of forest were removed. If our hypo- thetical estimate of the bird population of 1800 was correct, the decimation of IIli- nois forests in approximately 100 years was tantamount to the elimination of about 38,000,000 breeding birds from the state. Hicks (1935:306) suggested that the orginal forest in eastern North Amer- ica, because it offered relatively little edge, may have been poor bird habitat. Even if it was poor habitat and our estimate for 1800 was considerably high, 19th century deforestation must have taken a tremen- dous toll of Illinois birds. Areas adjacent to the Illinois country were also coming under the plow, and forests that remained must have been quickly populated to satu- ration. In the 19th century, also, grassland and marsh habitats were being transformed. By 1830, Illinois had nearly 160,000 whites (Anon. 1832:38). By 1850, it had 12,000,000 acres in farmland (Anon. 1936:151); the farm acreage almost dou- Intinoris NaArurAL History SURVEY BULLETIN Vol. 28, Art. 3 bled in the next decade and reached about 33,000,000 by 1900. The acreage of corn, oats, and cultivated hay more than dou- bled between 1866 and 1900 (Anon. 1936:153, 155, 165), supplanting most of what remained of the original 36,000,000 acres of natural habitats. What was left by 1900 was about 3,500,000 to 4,000,000 acres of forest (some of it grazed), about a million acres of prairie grasslands and marsh combined, and a vast expanse of -land in various stages of cultivation. Most of the cultivated habitats, new to Illinois, were without an avifauna. Some prairie species held on in marginal prairie acre- age, and for a number of prairie birds there was probably little hardship in the transition from wild prairie to tame or cultivated hay, or to pastureland that was not overgrazed. In 1900, the row crops, plowed fields, and small grain fields, which occupied nearly 20,000,000 acres, were for breeding birds largely a void to be partially filled later by the horned lark. Particularly in southern Illinois, de- forested areas that did not come immedi- ately under cultivation were quickly oc- cupied by a shrub flora and avifauna. The century that saw the Illinois forests deci- mated brought approximately 300,000 acres of orchards into being, and, between the marginal forest species and the mar- ginal prairie species of birds, the orchards had a ready-made avifauna. In that cen- tury, too, a notable acreage (probably about 350,000 acres by 1900) of human residential habitat developed in Illinois. Much of it rural and adjacent to orchards, residential habitat usually had tree and shrub cover of its own that claimed some segments of the forest and shrub avi- faunas. By 1900, over much of Illinois and the Midwest, there was beginning to be an agriculture-adapted avifauna. The trends of change were established, and the ensu- ing 60 years saw them continued. As in previous times, some species adapted to the change. In a few cases, man unwittingly adapted the environment to suit the species. The past 150 years in Illinois have seen the beginning and development of a spe- cialized kind of evolution. Albeit unwit- ting, it is, nonetheless, evolution by man- agement. The pattern of change is not EE ——————— ee ee October, 1963 Graper & GRABER: basically different from that in previous times, when other species of animals probably “guided” evolution to some ex- tent, though the rate of change may never before have been so fast. In little more than 100 years, the Illi- nois landscape changed immensely, from a few relatively high density habitats with an estimated June population (primarily nesting adults) possibly as high as 97,000,- 000 birds in 1800 to the diversified, man- aged habitats of 1907, which supported about 61,000,000 birds. In the next half century, the state avian population changed but little in total number. There is more to the picture of changing bird populations in Illinois than these gross population figures can tell. None of the population changes, of course, represented a general decrease or a general increase in the whole population. Of the 40 most abundant species of birds in the state, 17 showed notable population increases in the half century, 17 showed decreases, and 6 had about the same populations in 1907— 1909 as in 1957-1958. There was selec- tion, adaptation, extirpation; in_ short, there was evolution continuing. If we emphasize the changes of the half century between the two surveys, it is only because of the temporal limits of our data, for the patterns of change that led into the 19th century are continuing still. Specific Changes in Avifauna The basic patterns of change in the Illinois avifauna during the five decades between the two surveys can best be pre- sented by example. For many of the changes observed we can offer no explana- tion, and, in all cases, the reader should bear in mind that it is easy to oversimplify so complex a phenomenon as evolution. Unless otherwise stated, the population figures presented represent June popula- tions, primarily the adult nesting popu- tions. Earlier, we noted that there was no ready-made avifauna for most of the newly developing, managed habitats of 19th cen- tury Illinois. An increasingly greater use of some of these habitats by certain species of birds, both exotic and native, was a dominant trend of many decades. A case in point was the utilization of residential habitat by exotic species. Intro- Birp PopuLaTions In ILLINOIS 503 duced species thrive in managed habitats, and arrival of the house sparrow on the continent could not have been timed much better to take advantage of the swelling acreage of residential habitat. In 1907— 1909, the house sparrow was already a part of the Illinois avifauna, and was, in fact, probably the most abundant species in the state, with a population of at least 5,300,000 birds. The sparrow population was only slightly higher in 1957-1958 than in 1907-1909; in the intervening years, the house sparrow, like man, had become increasingly urban in distribution. The starling, which was not even present in the state until about 1926, well after the early surveys, attained by 1957-1958 a state breeding population of at least 3,- 100,000 birds, most of them in residential areas. What effect the starlings had on other cavity-nesting species can only be sur- mised. At least partly coincidental with increasingly greater numbers of starlings, flicker populations in the state fell from about 2,300,000 in 1909 to 300,000 in 1957, and the numbers of red-headed woodpeckers declined from 1,300,000 in 1909 to 130,000 in 1958. These native birds are not strictly forest species, but in- habitants of marginal, savanna-type, or even residential habitats, and they almost certainly came into competition with the starling. In recent years, flicker popula- tions in residential habitat were inversely proportional to the starling population, and starling numbers are presumably still increasing. Such native cavity nesters as the red-bellied and hairy woodpeckers, which are more restricted to the natural forest habitat, have not had to compete much with the starling and have shown no population decline. The evidence against the starling, though circumstantial, appears incriminating. During the habitat changes of the 19th and early 20th cen- turies, some native species found a niche in man’s residential habitat, but, to the medium-sized cavity nesters in this group, the introduction of the starling was de- structive. These exotic species were adapted to the residential habitat even before their intro- duction into Illinois. Iwo native species, the chimney swift and purple martin, were probably adapted to the urban situation 504 long before 1900. From a broad ecological background in 1907-1909, the robin pop- ulation in Illinois had, by 1957-1958, come to survive almost entirely in residen- tial habitat. Like the human population, the robin population has been concentrated particularly in northern IIlinois. Adaptive utilization of cultivated habi- tats extended to some open-country birds. Two examples deserve special discussion here. At least since the time of the early surveys (and presumably in previous ages), redwinged blackbird populations have attained their maximum densities in cattail marshes. In 1907-1909, though redwings occurred in prairie, hayfields, and other habitats, most of the state pop- ulation, which numbered about 5,000,000 birds, was in marshland. By 1957, the population numbered over 8,000,000 (11,- 000,000 in 1958), and most of the Illinois population was in cultivated habitats, par- ticularly mixed hay. In the period 1907— 1957, marshland, which had been largely restricted to the northern half of the state, dwindled to a tenth of its 1907 acre- age, and sod grasslands gave way increas- ingly to cultivated hay throughout the state. In this more widely distributed habitat, the redwing population swelled. The redwing may be expanding its utiliza- tion of secondary habitats even further. For instance, there is clear indication of increased use by the redwing of small grain fields, a habitat reservoir amounting to several million acres. This trend prom- ises further increase in the redwinged blackbird population. Even more spectacular than the popula- tion increase of the redwinged blackbird was the change in population of the horned lark. Between these two species, there was a subtle, but basic, difference in the mechanism of change. For the red- wing, marshes were, and still are, the fa- vorite habitat (judged from population densities) ; yet the redwing invaded a sec- ondary habitat that by 1957 supported most of the population. For the horned lark, man unwittingly created what proved to be an “optimum”’ habitat. Be- fore white settlement, the horned lark probably resided in the relatively barren parts of the prairie grassland, and its pop- ulation was probably not very great. The Ittinois NATURAL History SuRVEY BULLETIN Vol. 28, Art. 3 lark avoids tall cover, and bare ground is apparently an important part of its habitat. The great 19th century expansion of agriculture opened a vast land to the lark. With white settlement, increased grazing on the primary grasslands im- proved, for the lark, the original habitat, but even from pastures the lark moved in- creasingly to tilled land. The newly opened habitats were not saturated in 1907-1909 when the Illinois horned lark population was under 1,500,000 birds; by 1957-1958 there were about 5,000,000 horned larks in the state. For the horned lark, this population change in Illinois was probably representative of changes in other parts of the Midwest (Hicks 1935:308). Specialization in Managed Habitats The adaptation of bird species to the cultivated scene was but one major force in shaping the present avifauna. The culti- vated habitats themselves became more spe- cialized through changes in management. Here, for one example, we can refer to changes in orchard management to show at least two ways in which bird popula- tions were affected. While the density of the total bird population in orchards was about the same in 1957-1958 as in 1907— 1909, certain species, principally insectiv- orous and frugivorous types such as the eastern kingbird, robin, blue jay, the mim- ids, and orchard oriole, tended to disap- pear from the orchard avifauna. At least some of these species maintained or even increased their population densities in other habitats. Why they should have de- clined in orchard habitat particularly is a problem that needs further study. The in- creased use of insecticides in orchards and the development of organic insecticides may have had some bearing on the change. Much of the orchard acreage in 19th and early 20th century Illinois was composed of noncommercial farmyard orchards that probably received little insecticide spray- ing. Later these farmyard orchards gave way largely to commercial stands that re- ceived regular treatment with insecticides. Both the change in size of individual orchards, from family farm plots to large commerical stands, and the great decline in total acreage of orchards had their ef- fect on the avifauna. The commercial tracts of 1957-1958 had a decidedly uni- October, 1963 GrapeR & GRABER: Birp PopuLATIONS IN ILLINOIS 505 AE hala Fig. 29.—Southern Illinois landscape in June, 1907. The distribution of open fields and scattered clumps of shrubs and trees suggests a kind of savanna area. This type of cover distri- bution greatly favored a large variety of bird species. The loss of this habitat arrangement in recent times has contributed to a loss of avifaunal variety in Illinois. The photograph was taken 4 miles west of Shetlerville, Hardin County, June 28, 1907, by Alfred O. Gross. form aspect and offered much less edge than did the small farm plots of previous decades. To many species of birds, edge or mar- ginal habitats are extremely important; after 1900, we entered an era of increas- ing field size and agricultural specializa- tion in which edge habitats were dimin- ished. The practice of removing hedge- rows and other field-edge vegetation, as well as isolated trees within cultivated fields, became increasingly prevalent. Part of the modern practice of clean cultiva- tion is the reduction of weeds in pastures and crops of all kinds through mowing or the use of chemicals; this practice may af- fect bird populations by erasing some nest- ing and foraging niches (Scott 1958:389). Now even fences are being eliminated from field edges in many parts of the state. Elimination of these fences in effect results in the elimination of a multitude of singing perches for birds. Its influence, if any, on bird life in the state is a subject that needs research. In the late 19th and early 20th cen- turies, much of the land of Illinois had the aspect of a kind of savanna, figs. 29 and 30. This savanna-type habitat, a transitional stage between the natural post- glacial habitats and the specialized block terrain of agricultural management, has been largely eliminated. Just as 19th cen- tury deforestation removed a segment of the fauna from large areas of the state, so 20th century elimination of savanna- type habitat removed another group of birds from extensive areas. An important change in the Illinois avi- fauna during several recent decades was the waning, on a massive scale, of certain bird populations, particularly in the south- ern zone of Illinois. Many species were involved in this change, including at least the following: upland plover, yellow- billed cuckoo, mourning dove, flicker, red- headed woodpecker, eastern kingbird, blue jay, mockingbird, brown thrasher, robin, orchard oriole, lark sparrow, chipping sparrow, and field sparrow. For all of these species (combined) the net popula- tion loss in southern Illinois between 1909 and 1957 amounted to +,000,000 breeding birds (minimum estimate). 506 Ittrinois NATURAL History SURVEY BULLETIN Most of the species involved in this decline have at least one major ecological characteristic in common: except for the upland plover they are species of marginal, edge, or savanna-type habitats. Most of them are, therefore, species that probably increased greatly in population after 1800 as the land was transformed from its pri- meval state and broken into small farm / Fig. 30.—Landscape near the Ohio River, Hardin County, southern Illinois, 1907 and 1963. Upper picture taken 3 miles west of Cave-in-Rock, July 1, 1907, by Alfred O. Gross. Lower picture, same area as upper picture; taken May 19, 1963, by Richard R. Graber. Timber is filling in the old savanna-type habitat. The barn in the distance at the left in lower picture was built on the site of the barn shown in the 1907 picture. This farm has been owned by the same family for many years. Vol. 28, Art. 3 tracts. These species probably reached a peak around the turn of the century. Their decline began after 1900, as the number of farms and the acreage of sod grassland decreased, as cultivated fields in- creased in size, and as clean farming meth- ods removed edge shrubs, solitary shade trees, and family orchards. Most of these habitat changes are still continuing. October, 1963 Graper & GRABER: Population Density and Avifaunal Variety The increased specialization in man- aged habitats, with consequent diminish- ing of the savanna-type habitat, was only one ecological change that effected a loss of avifaunal variety in Illinois. Another ecological change having a similar effect was the adaptation of particular species to managed habitats. If we examine the bird habitats and their associated faunas, we can see a direct relationship between the complexity of a habitat and the complexity of its avifauna. Row crops, which offered few niches and few types of niches for birds, were the poorest of the habitats both in numbers of birds and numbers of species. Woody habi- tats, which offered many niches and many types of niches for birds, supported high populations and varied avifaunas. Beyond this primary direct relationship between density and variety, which can be seen in the whole gamut of habitats and avifaunas, another relationship between population density and faunal variety characterizes managed habitats only. By reducing floral variety in a habitat, man increases habitat specialization, therefore faunal specialization, and, in the transition Birp PopuLaTIons IN ILLINOIS 507 from natural to managed habitats, avi- faunal variety tends to decline while pop- ulation density tends to increase. The basic difference between natural and managed habitats can best be illus- trated with specific examples by consider- ing the faunal characteristics of a natural habitat and its managed counterpart. Thus, uncultivated grasslands supported a greater variety of common bird species than did the hay crops, but the hay crops supported denser populations. Residential habitat, a modified type of forest, support- ed much denser populations of birds, but a much smaller variety of species than natural forest. The greater the degree of specialization in the habitat and its con- stituent avifauna, the higher the popula- tion density can be. Cause and effect in the relationship be- tween population density and avifaunal variety are difficult to establish, but ulti- mately they relate to the variety and num- ber of niches that a habitat offers and to the interspecific competition for these niches. Characteristically, managed habi- tats offer a large number of niches, even though a small number of niche types, and the bird species best adapted to these niches occupy them so completely as to Table 56.—Estimates of breeding populations of common species of birds in Illinois, 1909 and 1957. The estimates are for all acres of the habitats accounted for in this study. The species listed comprised about 70 per cent of the birds in these habitats in the years indicated. 1909 1957 Species Number Species Number House sparrow yates 5,300,000 Redwinged blackbird = 8,400,000 Redwinged blackbird _ | 5,100,000 Elouse spatrowe = 6,100,000 Commonjerackles 1. 4,100,000 Horned: larkes =e 5,600,000 Meadowlark (spp.) ---_-____ - 4,000,000 Meadowlark (spp.) ye 3,800,000 Mourning dove. ie 2,500,000 Common grackle_ 3,600,000 Yellow-shafted flicker 2,300,000 DICkCis sede se Se eee ee 3,400,000 Field sparrow__.._- UNTER 2,100,000 Stanlinewe eeeseee eevee ee 3,100,000 LRG) OV. Ee cee 1,900,000 Miounninesd ove... = 2,000,000 Brown-headed cowbird 1,800,000 Bobolink sees se ese 1,900,000 I Gkicisse memes ote BE a ah 1,700,000 Brown thrasher eo ee pe ee ake 1,600,000 BAUS TEN ea ele eee 1,600,000 Red-headed ea Nuits ¢ 1,300,000 Common crow_ ue Ms ee 1,200,000 BODO Kees 22 oS ae 1,200,000 tndigobunting: == = 850,000 Horned) lankoe i seem 840,000 Bobwhites* 2-025. a Ses) 840,000 oa 40,230,000 Tati) went ete ee ew aL OO OOD 508 Intinoris NATURAL History SURVEY BULLETIN exclude other species of birds. The end re- sult of such occupation is an avifauna with high population density but little variety. Pertinent here is the fact that in each of the managed high density habitats used as examples above (hay crops and residential areas) part of the bird population was composed of species (purple martin, house sparrow, starling, and redwinged black- bird) that show a high degree of intra- specific tolerance. It is such species, par- ticularly, that increased in population after 1909. We must bear in mind that managed habitats, which have poor avi- faunal variety, are the expanding habitats. Since the turn of the century, the acreage of cultivated hay has grown as the acreage of prairie grasslands has dwindled. The trend toward specialization of habi- tats and their associated avifaunas (elimi- nation of savanna-type habitat was a par- allel trend) tended to reduce the number of bird species that could be classed as common in the state. A reduction in com- mon species has become apparent even since 1909. If we arbitrarily define the common species as those comprising 70 per cent of the state population, we find that there were, in the Illinois avifauna, 18 common species (about 40,000,000 birds) in 1907-1909 and only 14 common species (42,500,000 birds) in 1957-1958. Data for 1909 and 1957, the years of best cov- erage, show an even greater difference in avifaunal variety, table 56. Population Changes and Latitude Although specialization of habitats and adaptation by particular species to these habitats were dominant forces of change in shaping the present Illinois avifauna, certain special changes were important enough to deserve elaboration. We noted earlier that a number of species of birds suffered population losses, particularly in the southern zone of the state. No single factor could account for the waning pop- ulations in all of these species. The popu- lations of most of these species had been highest in 1907-1909 in the southern zone, and therefore that was the zone in which they had the most population to lose. Most of these species lost population in other zones, also, but a few—for ex- ample, the catbird and robin—actually in- creased their northern populations, while Vol. 28, Art. 3 losing in the south. Others lost propor- tionately less in the northern zone than in the southern. The brown thrasher pop- ulation, for example, fell from about 160,- 000 birds (1907-1909) to 130,000 (1957-1958) in the northern zone (about 20 per cent loss), but from 800,000 to 180,000 in the southern zone (about 80 per cent loss). The effect of these specific changes can be seen and expressed in terms of the entire state population of birds, for, between 1909 and 1957, the breeding-bird populations of northern and central Illinois actually increased, while the breeding-bird population in the south- ern zone declined, or, at best, merely held its own. Why, within a species, did the population in the northern zone survive better than that in the southern? This question suggests another group of prob- lems in Illinois ornithology that need fur- ther investigation. It is a mistake to as- sume that all of the species showing decline are responding to the same factors, though to some extent they may be. The fact that the population losses varied with latitude suggests the possi- bility of climatic influences on the popu- lations. The continent has probably been in a generally warming trend since the last glaciation; the temperature climb has been studied in detail since 1885 (Con- over 1953). How, or if, this climatic warming has affected survival of breed- ing birds remains to be determined. Per- tinent here are the notable changes in winter distribution of Illinois birds. Sev- eral species, including the mourning dove, mockingbird, robin, the meadowlarks, red- winged blackbird, swamp sparrow, and song sparrow, either extended their win- ter range northward in the state between 1909 and 1957 or wintered in Illinois in larger numbers in 1957-58 than in 1906— 07. The winter (January) population of birds in Illinois increased from about 30,- 000,000 in 1907 to 55,000,000 in 1957. The factor or factors that effected popu- lation changes in the state winter popula- tion may also have influenced the breed- ing population. Range Extensions Among the types of change in the IIli- nois avifauna between 1909 and 1957, range extensions by a few species deserve | | : | ee se October, 1963 Graper & GRABER: special mention. Of the common species censused, at least seven, all but one pri- marily southern forest species (turkey vul- ture, red-bellied woodpecker, Acadian fly- catcher, tufted titmouse, Bell’s vireo, car- dinal, mockingbird, and probably the Car- olina chickadee), extended their breeding range northward, and four, all icterids (bobolink, western meadowlark, yellow- headed blackbird, and Brewer’s black- bird), extended their range southward or southeastward. The larger number of spe- cies moving north than south probably re- flected the fact that deciduous habitat species were more numerous in the south. In addition to the species that made range extensions, there were a few species that greatly increased their breeding popula- tions in one zone particularly. Probably the most notable example was the barn swallow, which enlarged its southern zone population tremendously from a very low level in 1907-1909. In most cases, range extensions occurred from saturation or near-saturation popula- tions in adjacent areas. The red-bellied woodpecker, for instance, was essentially a southern species in 1907-1909, with a saturation population in its primary habi- tat (forest) of about 5 birds per 100 acres. By 1957, this species had attained popula- tions of the same density in the central zone and was still spreading northward, though populations in the northern zone were sparse (1 bird or less per 100 acres). At least two species, the turkey vulture and mockingbird, spread their populations northward despite thinning in the south- ern zone. The range extensions of the several species of icterids mentioned above fit a broad pattern of change. All of these species experienced notable population in- creases between 1909 and 1957; all are marsh-inhabiting or open-field representa- tives of the blackbird family. Such a con- sistent trend toward population increase among the species of one family suggests the possibility of some particular genetic vigor, or at least a genetic unity that makes them all favorably responsive to the changes that man has wrought. The grackle, which qualifies both genetically and ecologically for this group, merely held its own between the two survey pe- riods, but it found a niche in the expand- Birp POPULATIONS IN ILLINOIS 509 ing urban habitat and should, in time, in- crease; the two strictly arboreal members of the family, the orchard oriole and the et oriole, suffered population de- cline. Habitats and the Future of the Avifauna In a very general way, we have traced the development of our present Illinois avifauna. To know more precisely where the avifauna is in its sequence of develop- ment, and what we might expect in the way of avifaunal changes in the near fu- ture, we need to consider in more detail the relative availability, and the value to birds, of various Illinois habitats. We can evaluate a habitat both in terms of the number of birds it supports and the num- ber of species it supports. If we arrange the habitats according to the number of breeding birds they supported, listing those with highest population densities first, the sequence for 1957-1958 was urban resi- dential areas, marsh, shrub, orchard, hay crops, forest, grassland, oats, wheat, the row crops, and bare-field or plowed ground. The same habitats arranged in order of decreasing avifaunal variety were forest, shrub, orchard, urban residential areas, marsh, grassland, hay crops, oats, wheat, row crops, and bare-field or plowed ground. Row crops comprised over a third of the state acreage in 1957-1958 and are unlikely to diminish in acreage in the fore- seeable future. These crops have some value as foraging habitats for several spe- cies of birds, but there is no indication that species other than the horned lark depend significantly for their survival on this vast acreage. Acreages of small grain crops, particu- larly oats, declined between 1930 and 1957, and most of the lost acreage of these crops went into row crops. The change represents a loss to the Ilinois avi- fauna in terms of both numbers of birds and faunal variety. However, no species of bird is now entirely dependent upon the small grain habitats; these habitats form a kind of overflow area for species that usually attain higher population den- sities in hay crops and grassland. If hay and grasslands disappear, part of the avifauna, particularly adaptive species 510 such as the redwing, may survive princi- pally in small grain fields. The redwing population, already somewhat in need of control, may expand even further in small grain habitats; small grain acreage in the coming years should not decline much be- low its present level. Hay crops as a group, because they combine high population densities with large acreage, accounted in 1957-1958 for over 20 per cent of the state bird popula- tion, or at least 13,000,000 birds (in con- trast to 5,000,000 or 6,000,000 in 1907- 1909). In the 100 years before 1957, culti- vated hay was an expanding habitat, re- placing principally wild hay and pasture- land. The change tended to favor a few species, especially the redwinged blackbird and the dickcissel, and to increase the total number of birds in the state, while reducing the variety of common species in the areas in which the change took place. The change is continuing, and pastureland acreage is falling steadily, as livestock is being confined more and more to smaller feedlots. Coincidentally, the hay crops have been made more specialized. Much of the mixed hay acreage has given way to al- falfa, a poorer habitat for some of the prairie birds. In recent years, there has been some experimentation with other types of legume forage plants; if present hay types should ever give way to viny legumes, the hayfield avifauna would suf- fer greatly. Prairie marshland, the habitat with the second highest population density of birds, had all but disappeared from the state by 1957-1958 (60,000 acres in contrast to 560,000 in 1907), but it accounted for over a million birds, including a variety of species not adapted to other habitats. In the immediate future, the remnant marshland may be safe, but, as the human population expands and the land available for food production declines, pressure will come for the elimination of marshes and other uncultivated open-field habitats. Marshland acreage could actually be in- creased in the state, especially near large reservoirs. Because of the specialized char- acter of the fauna of marshland, conserva- tionists should encourage both the develop- ment of new marshland areas and the preservation of the existing marshland. The acreage of shrub-grown areas, Intinors NaturAL History SURVEY BULLETIN Vol. 28, Art. 3 which in 1957-1958 accounted for at least 2,000,000 birds in the state, probably increased slightly between 1909 and 1957, but it may decline seriously in the com- ing decades. Land-use patterns over most of the state are more stabilized now than they were even 50 years ago. Most shrub- grown habitat constitutes a transitional habitat that usually gives way to forest and depends on change of one sort or an- other for its continued existence. Areas now in shrubs are growing into forest, and the principal sources of shrub land (deforestation as it was formerly prac- ticed and retirement of cultivated fields) have been largely cut off. Forest will con- tinue to be harvested, but the harvest methods now most widely used (not the same as when trees were removed over great tracts of land) do not lead to shrub land. The amount of Illinois shrub land maintained by edaphic or topographic con- ditions is negligible. In addition, the acre- age of edge shrubs (fencerows and road- sides) and hedgerows is rapidly being greatly reduced. Edge shrubs and hedge- rows may have a higher population den- sity of birds than any other habitat in the state, and it is particularly regrettable that these habitats are being removed in an era when there is no shortage of food- producing acreage. Though of very lim- ited acreage (less than 100,000 acres), these edge habitats bring faunal variety to vast areas of open-field habitat where the fauna would otherwise be very limited; from the standpoint of efficient use of space for increasing populations of native species of birds, probably no easily obtain- able habitat is superior. Fortunately, many shrub-inhabiting spe- cies can survive in forest understory, but there are some, such as the prairie warbler, Traill’s flycatcher, and Bachman’s spar- row, which require open shrub arrange- ments; few shrub-dwelling species attain such high population densities in forest as in shrub-grown areas. Shrub habitat, like marsh, is important to the Illinois avi- fauna, both for its high population densi- ties and for the variety of specialized spe- cies it supports. Fortunately, land use in Illinois will probably never attain a state of equilibrium that will eliminate shrub- grown areas completely, but the day may come when some acreage will have to be October, 1963 GraperR & GRABER: managed specifically to create shrub habi- tat in order to maintain an interesting seg- ment of our avifauna. In little more than a century, orchard habitat in Illinois came into existence, ex- panded to an area of over 300,000 acres that supported nearly 2,000,000 breeding birds, and then decreased drastically. To- day, partly because of the limited acreage, the bird population (about 110,000) in orchards of the state is almost negligible and will probably remain so in the coming decades. Forest, the woody habitat with the most varied fauna but lowest population den- sity, will probably continue to increase slightly in acreage in the coming years. This increase will help to increase the state population of birds and maintain the variety of species. Like other natural habi- tats, forest may ultimately be endangered by the swelling human population with its needs for lumber, food, superhighways, dwelling areas, and trading centers. The elm diseases, which have left dead trees in forests throughout much of [Ili- nois, have created a special habitat that may for a short time favor population in- creases among certain picids and other cavity-nesting birds. Urban residential areas, which now boast a higher bird population density than any other habitat except edge, occupied an almost inconsequential acreage only 100 years ago. By 1909, urban area in the state was up to 350,000 acres and ac- counted for about 3,000,000 birds (6 per cent of the state population); by 1958, the area exceeded 800,000 acres, account- ing for nearly 8,000,000 breeding birds (13 per cent of the state population), and Was growing at an ever-increasing rate. The end of this growth is not in sight, and, because urban areas are claiming an increasingly important role in the develop- ment of the Illinois avifauna, this habitat deserves careful and intensive study. Most of the state population of introduced prob- lem species (starling, house sparrow, and rock dove) is produced in residential habi- tat. To some extent, these introduced species are probably effecting limitations on native species in the urban residential avifauna, but, even if the exotic species were not present, the urban fauna would be restricted in variety. The house sparrow Birp PopuLaTIONS IN ILLINOIS 511 population appears to have reached the saturation point, at least in old urban areas, but, because the urban residential habitat is expanding, the sparrow popula- tion will increase. The starling also should continue to increase in numbers; its popu- lation may not yet have reached the sat- uration point in any habitat. To date, conscious efforts to control sparrow and _ starling populations by planned elimination of their nesting sites have been negligible. The “gingerbread” house and similar architectural patterns of past decades, because they offered a multi- plicity of nesting and roosting sites, were probably especially favorable to the spar- row and starling. Few native species make use of human dwellings; therefore, build- ing design offers an important and specific technique for the control of the three in- troduced problem species. “The common practice by realtors of planting fast-grow- ing softwood trees in new housing addi- tions probably favors some native species of birds. The practice also favors the starling. Landscape architecture offers an- other effective avenue of control for prob- lem species. From an economic standpoint it is, of course, not feasible to quickly supplant established housing and_land- scape features, but at present the acreage of residential habitat in Illinois is expand- ing greatly, and some effort should be made to at least study the possibilities of planned control of problem bird species by building and landscape design. Residential habitat itself is changing in character. The newly developing large acreage of suburban housing will, for some years, have limited arboreal habitat for birds, and the house sparrow will probably dominate the early stages of suburban birdlife. The absence of large trees in new suburbs and the low-level dimensions of many suburban houses should discourage starlings to some extent in these areas. The bird-attracting poten- tial of new housing and landscape designs remains to be determined. Because of the absence of large trees, grackles, flickers, crested flycatchers, and some of the other prominent species of older residential areas will be largely missing from the suburbs for some time. Developing small trees and shrubbery should favor some native spe- cies. The robin, which seems to have be- come dependent on residential habitat, and the mourning dove should increase their populations. Before 1980, there will probably be over 1,000,000 acres of urban residential habitat in the state, with a bird population numbering over 10,000,000 and including as many as 6,000,000 house sparrows and starlings in this habitat alone. Properly managed, this acreage could be made more pleasant for its human inhabitants and at- tractive to a variety of desirable native species of birds. Urban and suburban busi- ness districts, which are beginning to absorb a significant fraction of the state acreage, represent an almost total loss as habitat for native birds (except night- hawks), but they support large popula- tions of the three introduced species. Road and highway surfaces and rail- road trackage also represent lost habitat acreage for birds. We have estimated that about 600,000 acres of Illinois land were covered by road (surfaces only) in 1910, and over 1,100,000 in 1960. More acre- age will go under concrete as highways are widened and work on four- to eight- lane interstate routes is expanded. As many as 1,500,00 acres may thus be uti- lized in the state by 1980. Along the margins of this highway system is a grassy roadside cover that in 1960 occupied nearly 400,000 acres along primary roads alone. This habitat—useful to a few na- tive species of birds, notably meadowlarks —should increase in acreage in the coming decades, especially along interstate routes. This road-edge habitat warrants special study for its value to birds. An unknown in relation to the expan- sion of these urban and highway areas is where the acres will come from; that is, what present habitats will be reduced to make room for the expansion? The proba- bility is that most of the acreage for the expansion will come from open cultivated fields, particularly row crops, which would represent little loss to birds; in some areas, in the southern zone especially, some for- est or shrub acreage may fall to the burgeoning cities and highways, and this would represent a definite loss. The habitat changes discussed above had a profound effect on the Illinois avi- fauna, but it is difficult to understand some of the observed population changes, I_uinois NatrurAL History SURVEY BULLETIN Vol. 28, Art. 3 and probably it is misleading to generalize about them. It is easy to see that the re- duction in acreage of orchards, a habitat notably concentrated in the southern zone, could have reduced the orchard oriole pop- ulation in this zone from about 400,000 birds in 1907-1909 to 100,000 in 1957-— 1958. On the other hand, it is difficult to understand why the blue jay population should have lost over half a million birds in the southern zone in a period when woody habitats were expanding. It is rea- sonable to assume that the introduction of the starling may have played some role in the decline of such cavity-nesting species as the red-headed woodpecker and flicker and that the expansion of woody habitats had a bearing on the increase in the indigo bunting. But what of the virtual elimina- tion of the lark sparrow, which in 1907— 1909 had a population in the southern zone of at least 300,000 birds? Here, for the most part, we can only point to the population changes; we cannot explain them. There is room for speculation and there are many factors to consider—cli- matic changes, habitat changes, competi- tion, genetic vigor, and others—but all paths of speculation lead inevitably to more and more questions and the ultimate realization that each of these species needs special, detailed study. We should not for- get, either, that the apparent population changes may represent transient conditions —normal fluctuations or temporary set- backs from which any or all of the species mentioned may come back in force. Among the factors that complicate the interpretation of apparent population change in a given species is a lack of pre- cise information on the relative impor- tance of various habitats to that species. The census data revealed that few species of Illinois birds spend the day solely in only one or two habitats. Even some for- est species spend time in open fields, figs. Si" ands32. We have hypothesized that the high bird population of a few relatively stable natural habitats characteristic of primitive Illinois declined in the 19th and early 20th centuries as the natural cover gave way to the agricultural and other man- aged habitats that came with white settle- ment and that, although for most of these new Illinois habitats there was no real October, 1963 Graper & GRABER: avifauna, an agriculture-adapted avifauna was probably beginning to develop even as agriculture came to dominate the land. When the Illinois bird population reached its low we cannot say; by 1907— 1909, at a level of 61,000,000 birds, it may have been climbing. In the next 50 years, despite waning populations in a number of species, especially inhabitants of savanna-type areas, the total Illinois bird population remained about the same, principally because of a new introduction, the starling, and expanding populations in the relatively few species that comprised the avifauna for managed habitats. Be- BARE PASTURE, SPECIES HORNED LARK Birp PoPpuLATIONS IN ILLINOIS HAY, FIELD GRASSLAND CLOVER GRAIN 513 cause of these species the state population will probably increase in the coming dec- ades. Even the redwing and horned lark populations have probably not yet reached saturation levels, and there may ultimately be increased use of croplands by a few other species. Our prognostication that the number of birds in Illinois will increase in coming decades is based primarily on a considera- tion of changes in habitat and the response of a few species to these changes. In truth, we do not even begin to know all of the factors that will affect future populations of Illinois birds. URBAN RESIDENTIAL SMALL marsH SHRUB, forest ORCHARD — KILLDEER = SAVANNAH SPARROW MEADOWLARKS BOBWHITE Ht H ++58 1] Se ae ae mT Bh , t 4 + BARN SWALLOW + # UPLAND PLOVER GRASSHOPPER ‘SPARROW —————_—_ i ————_ i — i eee BOBOLINK DICKCISSEL 25 %0 50 100 PER CENT SCALE 4 VESPER SPARROW Ls | a CHICKADEES MOCKINGBIRD TOWHEE i" ++. ORCHARD ORIOLE CHAT a Lill YELLOW-B, CUCKOO FIELD SPARROW + TTT ail, ' INDIGO BUNTING SST : YELLOW THROAT 4 Hill BLUEBIRD -———_——_—_—_—___&@*"—_ GOLDFINCH 4 CATBIRD } CARDINAL + cel BROWN THRASHER CRESTED FLYCATCHER DOWNY WOODPECKER + TUFTED TITMOUSE BLUE JAY =! RED-H. WOODPECKER + ~ - PURPLE MARTIN 1 HOUSE WREN 7 oemer otT STARLING ae || ba ROBIN ++ HOUSE SPARROW — | tet CHIMNEY SWIFT . MOURNING DOVE FLICKER KING BIRD CROW | REDWINGED BLACKBIRD GRACKLE ea a a agree a5 - COWBIRD SONG SPARROW To) tl | be a apne Teagamee Beem | TT + + + a +t # + ap ee ee fet | | Sggeraee Beate get -etet BARE PASTURE, HAY, FIELD GRASSLAND CLOVER GRAIN MARSH URBAN RESIDENTIAL SMALL SHRUB, FOREST ORCHARD Fig. 31—Habitat preferences of common species of Illinois birds in summer as indicated by the population density of each species in each habitat. Each black bar represents the relative density of a given species in a given habitat; the sum of the relative densities for each species is 100 per cent. Data are from all zones of the state and from all summer censuses. 514 Intrnois NaturAt History SURVEY BULLETIN BARE PASTURE SPECIES FIELD GRASSLAND ’ FALLOW Vol. 28, Art. 3 HAY, SMALL GRAIN SHRUB, cLover stusaLe HEAT opcHarp FOREST SPARROW HAWK -—————@ ——¢&$ + + —____+—__________-4 Est ht + ——_ MOURNING DOVE LAPLAND LONGSPUR ————+\_—._@¥_——_ 1 HORNED LARK SWAMP SPARROW REDWINGED BLACKBIRD ——#—@—4@_@@i@i@a@i i i i EASTERN BLUEBIRD —————4+_—_—8§ —__——<#@$_ —_#@_ +--+ #4 MOCKINGBIRD GOLDFINCH FLICKER SONG SPARROW —————————_+—__1#___ntd@*"_—___#___—__1+__—__1+—_I_ DOWNY WOODPECKER ————4—_+__—_.eoOH— YTV YASS a—a@»,_r-—_ : 0 25 10, 50 100 PER CENT SCALE PURPLE FINCH ————_2@2_ SS SUYHHJ_Y]_" ot WHITE —CROWNED SPARROW —+—@- —_+—_11"—_ rr WHITE-BREASTED NUTHATCH $A __—_ ir ——§_ $$ aA —_ rr} FIELD SPARROW CHICKADEES BOBWHITE HOUSE SPARROW ————+———__1———_1_#______#__ #1. —_4 STARLING JUNCO RED—H. WOODPECKER ———_——S oO or TURKEY VULTURE RED-BELLIED WOODPECKER —s#__#—_#77$7Y>YTS tO cROW ———_______—_‘#—_2#@ —@_____8@ ___}#______#_____}+__—_—_|—————_ BLUE JAY 4 —_$__+>—_—__+——__4-_____—_—\—\—\——_ i ——_ ROBIN rr WHITE—THROATED SPARROW —}-——————————_.@#”"]7?77?7?777]7 Si —— fp oe ii — nm o_—-— ss mM —mIII_ON-_ CARDINAL TREE SPARROW ———————_#—______@_ —____#_____}+_____}__—_/i- BARE FIELD GRASSLAND PASTURE, (Fai | ow HAY, SMALL GRAIN CLOVER STUBBLE SHRUB, NERD ORCHARD FOREST Fig. 32.—Habitat preferences of common species of Illinois birds in winter as indicated by the population density of each species in each habitat. Each black bar represents the relative density of a given species in a given habitat; the sum of the relative densities for each species is 100 per cent. Data are from all zones of the state and from all winter censuses. To the multiplicity of factors involved in this extremely complicated subject, man has, in recent years, added to the com- plexity. In a sense, we have entered into a new era characterized by the wide- spread, regular application to the land of potent chemicals—insecticides, herbicides, and fertilizers. The acreage of Illinois cornland treated with chemicals for con- trol of subterranean insects expanded from about 780,000 in 1958 (the last year of the second census period) to more than 3,500,000 acres in 1962 (Anon. 1963a:1). As we consider the increasing acreage of corn, soybeans, and other crops that are being treated with insecticides and herbi- cides, and the increasing acreage of road- side and other vegetation that is being killed with herbicides, we ask ourselves if we are not rapidly approaching the time when most of Illinois will be treated with toxicants of one sort or another. We are only beginning to understand some of the effects of these chemicals on birds. Among the most important research needs in the state are detailed, carefully planned, and controlled studies of the ef- fects of pesticides (insecticides and herbi- cides) on birds, their diets, their repro- duction, their survival. We have suggested that, with the increased use of insecticides in orchards, population densities of cer- tain species were reduced in this habitat. Mortality of birds as a result of applica- tions of pesticides in a wide variety of habitats and geographic areas has been described and discussed by many authors (including DeWitt & George 1959; Scott, Willis, & Ellis 1959; Anon. 1962). There is ample evidence that this mortality re- sults from both direct and _ indirect (through the food chain) intoxication (Bernard 1963:170, 188-90). Nesting success in a pesticide-treated area may be October, 1963 Graper & GRABER: greatly reduced because of loss of natural insect foods, or the intoxication of ju- venile birds or adults (Hanson 1952:305- 8; DeWitt & George 1960:8-9; and others). We are still short of data on the cumulative effects of sublethal doses of pesticides on individual birds and the long- term effects on whole populations. Par- ticularly pertinent here is the evidence that certain widely used chlorinated hy- drocarbons reduce reproductive capability in birds (DeWitt 1955:676; 1956:865-6; Anon. 1962:45-7). What effect the widespread use of in- secticides and herbicides in the various habitats will have on the future popula- tions of Illinois birds remains to be seen. Because cultivated lands and urban resi- dential areas are the habitats that are being most widely and regularly treated with pesticides, the very species of birds that have been increasing their popula- tions in recent years may, in coming gen- erations, be the species that decline. Man and the Avifauna Whatever the genetic or ecological char- acteristics of the species involved, it is abundantly clear that man, among the various forces that shape our fauna, is the dominant force of change. In his use of the land for food production, com- mercial enterprises, home building, and other purposes, he selects (albeit unwit- tingly) for some species of birds and per- haps inevitably against others. Birp PopuLaATIONS IN ILLINOIS 51 a In the history of a fauna, 50 years is an extremely brief period, and the coming years will probably accentuate the loss in avifaunal variety, even though the number of birds increases. The most unfortunate aspect of man’s domination of the land is not that he changes the environment but that he changes it so widely so quickly. Species evolution requires time. Natural cataclysms may alter habitats quickly but not widely, or widely but not quickly. It is man who combines the two, who changes the face of the earth not in mil- lennia but in decades. For the most part, man has utilized the land without regard for the natural fauna. In North America, conscious management of bird populations, except those of a few game species, has been negligible. Yet for the past several decades man has been un- wittingly manipulating bird populations on a wholesale scale. His domination has reached a critical and fearful level. Some obligation must go with this domination. Man has reached the stage when he must consider, in his manipulation of the en- vironment, more than just his own pri- mary needs. If there is to be a varied and interesting fauna for future generations to know, then management of the land must extend beyond human needs to the basic requirements of the fauna. Our lack of knowledge is the overriding deterrent to this type of management, but not the only one, and education of the public will have to follow the much-needed research. LITERATURE CITED Allen, J. A. 1880. Eastward range of the western meadowlark. Nuttall Ornith. Club Bul. 5:53-4. American Ornithologists’ Union 1957. Check-list of North American birds. 5th ed. American Ornithologists’ Union. 691 pp. Anonymous 1900— Christmas bird count. (A series of reports on annual Christmas bird counts, as pro- 1960. posed in Bird-Lore 2(6): 192. Reports published in Bird-Lore, Audubon Magazine, Audubon Field Notes, various issues and pages.) 1832. Abstract of the returns cf the Fifth Census. 22nd Congress, 1st Session, House of Representatives Document 269. 51 pp. Duff Green, Washington, D. C. [1936.] Illinois crop and livestock statistics. Ill. Dept. Ag. Circ. 438. 341 pp. 1962. Effects of pesticides on fish and wildlife: a review of investigations during 1960. U. S. Fish and Wildlife Service Circ.°143. 52 pp. 1963. Subterranean insects. The Illinois Natural History Survey Reports, February, 1963. 4 pp. Baker, Mrs. H. A, 1955— Two hay fields and grazed creek pasture. [Series of articles appearing under this 1961. and similar titles in annual breeding-bird census reports.] Audubon Field Notes, 1955, 9(6):423-4; 1956, 10(6):427-8; 1957, 11(6):447; 1958, 12(6):450; 1959, 13(6): 467-8; 1960, 14(6):498-9; 1961, 15(6):511. Barnes, R. M. 1912. Breeding birds of Marshall Co., Ill. Oologist 29: 325-8. Barrows, Walter B. 1889. The English sparrow (Passer domesticus) in North America, especially in its rela- tions to agriculture. U. S. Biol. Surv. Bul. 1. (Published as U.S. Dept. Ag. Div. Econ. Ornith. and Mammal. Bul. 1.) 405 pp. Bernard, Richard F. 1963. Studies on the effects of DDT on birds. Mich. State Univ. Mus. Biol. Ser. 2(3) : 155- 92. {[Chapman, Frank M.] 1900. A Christmas bird-census. Bird-Lore 2(6) :192. Conover, John H. 1953. Climatic changes as interpreted from meteorological data. Chap. 18, pp. 221-30, im Climatic change: evidence, causes, and effects; Harlow Shapley, ed. Harvard Uni- versity Press, Cambridge. 318 pp. Cooke, Wells W. 1915. Preliminary census of birds of the United States. U. S. Dept. Ag. Bul. 187. 11 pp. 1916. Second annual report of bird counts in the United States, with discussion of results. U. S. Dept. Ag. Bul. 396. 20 pp. DeWitt, James B. 1955. Effects of chlorinated hydrocarbon insecticides upon quail and pheasants. Ag. and Food Chem. 3(8) :672-6. 1956. Chronic toxicity to quail and pheasants of some chlorinated insecticides. Ag. and Food Chem. 4(10) : 863-6. DeWitt, James B., and John L. George 1960. Bureau ‘of Sport Fisheries and Wildlife pesticide-wildlife review: 1959. U. S. Fish and Wildlife Serv. Circ. 84. (Special scientific report: wildlife.) 36 pp. Eifrig, C. W. G. 1927. Notes from the Chicago area. Auk 44(3) : 431-2. Ewing, J. A., in charge 1959. Illinois agricultural statistics, annual summary 1959. Illinois Co-operative Crop Reporting Service. Springfield. 74 pp. Forbes, Stephen A. 1907. An ornithological cross-section of Illinois in autumn. II]. Lab. Nat. Hist. Bul. 7(9): 305-35. 1908. The mid-summer bird life of Illinois: a statistical study. Am. Nat. 42:505-19. 1913. The midsummer bird life of Illinois: a statistical study. Il]. Lab. Nat. Hist. Bul. 9(6) :373-85. Forbes, Stephen A., and Alfred O. Gross 1921. The orchard birds of an Illinois summer. II]. Nat. Hist. Surv. Bul. 14(1):1-8 + pls. I-VI. 1922. The numbers and local distribution in summer of Illinois land birds of the open country. Ill. Nat. Hist. Surv. Bul. 14(6): 187-218 + pls. XXXV-LXX. 1923. On the numbers and local distribution of Illinois land birds of the open country in winter, spring, and fall. Ill. Nat. Hist. Surv. Bul. 14(10) :397-453. Graber, Richard R., and Jack S. Golden 1960. Hawks and owls: population trends from Illinois Christmas counts. III. Nat. Hist. Surv. Biol. Notes 41. 24 pp. [ 516 ] October, 1963 Graper & GraBeR: Birp PoPpuLaATIONs IN ILLINOIS 517 Hagan, William T. 1958. The Sac and Fox Indians. University of Oklahoma Press, Norman. 287 pp. Hancock, Joseph L. 1888. Impeded migration and destruction of birds at Chicago. Auk 5(4): 432-4. Hanson, Harold C., and Charles W. Kossack 1957. Weight and body-fat relationship of mourning doves. Jour. Wildlife Mgt. 21(2): 169-81. 1963. The mourning dove in Illinois. Il]. Dept. Cons. Tech. Bul. 2. 133 pp. Hanson, William R. 1952. Effects of some herbicides and insecticides on biota of North Dakota marshes. Jour. Wildlife Mgt. 16(3) : 299-308. Hickey, Joseph J., Editor 1937. Bird-Lore’s first breeding-bird census. Bird Lore 39(5) : 373-86. Hicks, Lawrence E. 1935. Small birds are not decreasing! Bird-Lore 37(5) : 303-9. James, Douglas 1962. Winter 1961-62: dominated by movements of boreal birds and marked by still low numbers of eastern bluebirds. Audubon Field Notes 16(3) : 306-11. Kendeigh, S. Charles 1944. Measurement of bird populations. Ecol. Monog. 14(1) :67-106. 1954. Oak-maple forest and forest edge (im Eighteenth breeding-bird census). Audubon Field Notes 8(6) :370-1. 1960. Oak-maple forest and edge (im ‘Twenty-fourth breeding-bird census). Audubon Field Notes 14(6): 502. Kendeigh, S. Charles, and Richard D. Brewer 1956. Oak-maple forest and forest-edge (im ‘Twentieth breeding-bird census). Audubon Field Notes 10(6) : 434. Kendeigh, S. Charles, Marshall B. Eyster, and Robert K. Stubbs 1950. Oak-maple forest and forest-edge (im Fourteenth breeding-bird census). Audubon Field Notes 4(6) : 300. Kendeigh, S. Charles, and Nancy Joen Forsyth 1959. Oak-maple forest and edge (im Twenty-third breeding-bird census). Audubon Field Notes 13(6) : 472-3. Kendeigh, S. Charles, and Walter Gillespie 1955. Oak-maple forest and forest-edge (im Nineteenth breeding-bird census). Audubon Field Notes 9(6):431. Kendeigh, S. Charles, Douglas James, and Charles Weise 1952. Oak-maple forest and forest-edge (im Sixteenth breeding-bird census). Audubon Field Notes 6(6) :310-1. 1953. Oak-maple forest and forest edge (im Seventeenth breeding-bird census). Audubon Field Notes 7(6) :347. Kendeigh, S. Charles, Robert V. Kennedy, George W. Cox, George C. West, and Walter L. Gillespie 1957. Oak-maple forest and forest edge (im Twenty-first breeding-bird census). Audubon Field Notes 11(6):452-3. Kendeigh, S. Charles, and Robert K. Stubbs 1951. Oak-maple forest and forest-edge (im Fifteenth breeding-bird census). Audubon Field Notes 5(6) :324. Kendeigh, S. Charles, and George C. West 1958. Oak-maple forest and edge (in Twenty-second breeding-bird census). Audubon Field Notes 12(6) :455. King, D. B., and R. K. Winters 1952. Forest resources and industries of Illinois. Ill. Ag. Exp. Sta. Bul. 562. 95 pp. Livesay, Ann 1951. The past speaks to you. III. State Mus. Story of Ill. Ser. 7. 32 pp. Musselman, T. E. 1941. Bluebird mortality in 1940. Auk 58(3) : 409-10. Rand, A. L. 1956. Changes in English sparrow population densities. Wilson Bul. 68(1): 69-70. Ridgway, Robert 1915. Bird-life in southern Illinois. IV. Changes which have taken place in half a century. Bird-Lore 17(3) :191-8. Ross, R. C., and H. C. M. Case 1956. Types of farming in Illinois: an analysis of differences by areas. Ill. Ag. Exp. Sta. Bul. 601. 88 pp. Scott, Thomas G. 1958. The ornithologist’s responsibility to the future. Wilson Bul. 70(4): 385-93. Scott, Thomas G., Yuell L. Willis, and Jack A. Ellis 1959. Some effects of a field application of dieldrin on wildlife. Jour. Wildlife Mgt. 23 (4) : 409-27. 518 Ittrnors NatuRAL History SURVEY BULLETIN Vol. 28, Art. 3 Shaw, Samuel P., and C. Gordon Fredine 1956. Wetlands of the United States: their extent and their value to waterfowl and other wildlife. U. S. Fish and Wildlife Serv. Circ. 39. 67 pp. Smith, Harry R., and Paul W. Parmalee 1955. A distributional check list of the birds of Illinois. Ill. State Mus. Pop. Sci. Ser. 4. 62 pp. Stone, George J. 1950. Breeding-bird census. Audubon Field Notes 4(2) :185-6. Temple, Wayne C. 1958. Indian villages of the Illinois country. Historic tribes. Ill. State Mus. Sci. Papers 2(2). 218 pp. U.S. Bureau of the Census 1913. Thirteenth census of the United States taken in the year 1910. Vol. V, Agriculture, 1909 and 1910. 977 pp. U. S. Government Printing Office, Washington, D. C. 1961. U.S. Census of Agriculture: 1959. Vol. I, Counties. Part 12, Illinois. 255 pp. U. S. Government Printing Office, Washington, D. C. Wetmore, Alexander 1940. A check-list of the fossil birds of North America. Smithsn. Inst. Misc. Collect. 99(4). 81 pp. Yeatter, Ralph E. 1943. The prairie chicken in Illinois. Ill. Nat. Hist. Surv. Bul. 22(4) :377-416. INDEX In this index, page numbers referring to figures and tables are in italic type; page num- bers for principal references are in boldface type. Of necessity, variation occurs in some of the terms indexed. For example, cornfield in the index may sometimes refer to corn in the text; slate-colored junco in the index may refer to junco in the text. Shrubs in one place may be synonymous with shrub-grown area in another. For certain sections dealing with bird species and with habitats, inclusive pages for each are given in boldface type; for example, Robin, 485-6, Pasture, 408-12. Within the inclusive pages for any of these items, no text references to subdivisions of the items are indexed; for example, the acreage of pasture and the bird populations in pasture as given in the text on page +09 are not indexed; however, the acreages of pasture shown in the graph on page 388 and mentioned on pages 440 and 457 are indexed under Pasture, as are the bird populations in pasture mentioned on pages 440, 441, and 457; dickcissel as mentioned on page 409 is indexed under the entry Dickcissel as a species in pasture. Common and scientific names of birds encountered in this study are listed in table 55, pages 459-62; the index includes references to the common but not the scientific names on these pages. Bird species account of, 458—500 encountered in strip censuses, 459-62 number of identified, 458 Bittern, American, 459, 463 as species in marsh, 425 Bittern, least, 459, 463 as species in marsh, 425 Blackbird spp., 509 Blackbird, Brewer’s, 461, 463 Acreage censused (see also under each habi- tat), 396, 443 Acreage data, sources of, 387-8 Airfields (airports), 442, 458 Alfalfa, 386, 414, 416, 418, 420, 421-2, 438, 438, 439, 439, 468, 469, 472, 477, 478, 479, 484, 486, 487, 488, 489, 490, 491, 492, 493, 495, 496, 497, 500, 510 acreage censused, 396, 423 acreage in state, 338, 441 range extension, 509 avifauna of, 423 as species in corn, 398; hay, 417; pasture, common species in, 424 411 statistical data on populations in, 423 Blackbird, redwinged, 46/7, 462, 490, 490-1, Annotated list of common bird species, 463—500 495, 508, 510, 513 Avifauna, specific changes in, 503—4 habitat preferences, 513, 514 population (statewide), 504 B population for all habitats in study, 507 Bare-field or bare-ground habitat, 397, 401, as species in alfalfa, 422, 423, 424; clover, 438, 439, 497, 509, 513, 514 420, #21, 422, 424; corn, 397, 398, 400, 400, Barley, 440, 448 446; fallow fields, 414, 475; forest, 432, acreage censused, 396 #55; grassland, 412, 4/3; hay, 389-90, Beans (see also Soybeans), 408, 471, 478, 482 390, 416, 417, 418, 419, 424; marsh, 424, Bird populations (see also individual species) 425; oats, 404, 405, 407; orchard, 429, 430, annotated list of common species, 463—500 430; pasture, 409, 410, 412, 412, 450; avifaunal differences between censuses, 463 plowed fields, 403; shrubs, 424, 425, #26, of common species, 1909 and 1957, 507 427, 428, 454; soybeans, 401, 402, 447; comparison of data for summer habitats, wheat, 406, 407, 408; woodland, 434 437-40 Blackbird, rusty, 461, 463 comparison of data for winter habitats, 453— as species in corn, 446 Blackbird, yellow-headed, 461, 463 density in three zones, 442-3, 457-8, 458 range extension, 509 loss between 1909 and 1957, 505 number of birds eliminated by forest remoy- al, 502 number of birds in summer habitats, 438—9 number of birds in winter habitats, 456 number of common species, 508 number of species in summer habitats, 439— 40 number of species in winter habitats, 456 previous to 1800, 501-2 statewide, 513 statewide summer, 440-3, 503 statewide winter, 456-8, 508 in summer habitats, 396—443 variations in statewide, 442 variations in summer and winter, 392-3 in winter habitats, 443-58 pote} as species in fallow fields, 475; marsh, 425 “Blackbirds,” 491 Bluebird, eastern, 393, 461, 462, 485, 486 habitat preferences, 513, 514 as species in clover, 427; corn, 398, 400, 445, 446; fallow fields, 415, 451; forest, 432, 455; hay, 418, 453; marsh, 425; oats, 405; pasture, 410, 450; plowed fields, #03; shrubs, 427, 454; small grain, 443; wheat, 449 woodland, 392, 434 Bluegrass, 409, 430, 451 Bobolink, 461, 489 habitat preferences, 513 range extension, 509 beste population for all habitats in study, 507 as species in alfalfa, 423, #24; clover, 420, 21, 422, 424; corn, 398; grassland, 413; 520 Intinors NATURAL History SURVEY BULLETIN hay, 389, 390, 417, 418, 419, 424; marsh, 424, 425: oats, 404, 405, 407; pasture, 410; shrubs, 427 Bobwhite, 459, 462, 466—7 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423; corn, 398, 445, 446, 446: clover, 420, 421, 422; fallow fields, 415, 451, 452; forest, 432, 453, 455; grass- land, 413; hay, 417, 419, 452, 453; oats, 405: orchard, 429, 430; pasture, 410, 450; plowed fields, 403; shrubs, 426, 427, 453, 454; small grain, #48; soybeans, #02; wheat, 407 Breeding species, definition of, 389 Bromegrass, +16, +20 Bunting, indigo, 462, 463, 494—5, 512 habitat preferences, 5/3 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421; corn, 398, fallow fields, 415; forest, 432, 435; grassland, 4/3; hay, 417; oats, 405; or- chard, 429, 430, 430; pasture, 4/0; plowed fields, 403; shrubs, 424, 425, 426, 427, 428; soybeans, 402; wheat, 406, 407; woodland, 434 Bunting, snow, 462, 463 as species in small grain, 448 C Cacti, frontispiece Caprimulgus spp. in forest, 433 Cardinal, 453, 462, 462, 493-4 habitat preferences, 5/3, 514 range extension, 501, 509 as species in alfalfa, 423; corn, 398, 445, 446; fallow fields, 475, 451, 452; forest, #32, 435, 436, 453, 455; hay, 4/8; oats, 405; orchard, 429, 430, 430; pasture, 410, 450, 452; shrubs, 424, 426, 427, 428, 453, #54; urban residential areas, 436; wheat, 407, 449; woodland, 392, 434 Catbird, 460, 463, 483-4, 484, 508 habitat preferences, 5/3 as species in corn, 398; forest, 432; hay, #18; marsh, #25; oats, 405; orchard, 429, 430; pasture, 410; shrubs, 424, 426, 428; urban residential areas, 436, 437, 437; wheat, 407; woodland, 434 Cattails, 424, 504 Cemeteries, 442, 458 Census, breeding-bird, in hayfields, 389-91 Census, strip area, size of adequate, 386-7 counties included in, 385, 386 data on areas of different sizes, 387 dates of, 385-6 description of method, 383—9 evaluation of method, 389—93 zones, boundaries between, 386 zones, how defined, 388 Chat, yellow-breasted, 461 habitat preferences, 5/3 as species in fallow fields, 475; forest, 432; orchard, 429; pasture, 4/1; shrubs, 424, 426, 427, 428; woodland, 434 Chickadee spp., 388, 460, 481—2, 482, 483 habitat preferences, 513, 514 as species in corn, #45, 446, 446; fallow Vol. 28, Art. 3 fields, 451; forest, 432, 435, 453, 455; hay, 453; pasture, 411, 450; plowed fields, 447 ; shrubs, 426, 428, 454; woodland, 392, 434 Chickadee, black-capped, 388, 460, 481-2, 482 Chickadee, Carolina, 388, 460, 481-2, 482 range extension, 509 as species in orchard, 429, 430; shrubs, 427 Chicken, greater prairie, 459, 463, 466 as species in clover, 420, 427; corn, 398; hay, 418; pasture, 411; wheat, 407 Chlorinated hydrocarbons, 515 Clover (clover fields), 418-21, 422, 468, 469, 472, 473, 513, 514 acreage in state, 338 Clover, Ladino, 420 Clover, red, 389, 414, 416, 418—20, 421, 422, 430, 438, 438, 439, 439, 466, 468, 469, 470, 472, 475, 476, 477, 479, 480, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 495, 496, 497, 499 acreage censused, 396, 420, 421 avifauna of, #2] common species in, 422, 424 statistical data on populations in, 420 Clover, sweet, 389, 414-6, 418, 420-1, 438, 438, 439, 469, 472, 477, 478, 479, 480, 484, 489, 490, 491, 492, 493, 495, 496, 499 acreage censused, 396, 422 avifauna of, 422 Common names of birds, list of, 459-62 Common species of birds breeding populations of, 1909 and 1957, 507 definition of, 387 habitat preferences, 513, 514 Control of problem bird species, 511 Coot, American, 459, 463 as species in marsh, 425 Cornfield (corn), frontispiece, 383, 386, 396, 397-401, 399, 401, 405, 406, 408, 438, 438, 439, 439, 440, 443, 443-7, 444, 447, 448, 450, 452, 456, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 490, 491, 492, 493, 495, 496, 497, 498, 500, 502, 514 acreage censused, 396, 397, 398-9, 443, 446 acreage in state, 388, 440, 445, 456 avifauna of, 398-9, 445, 446 bird populations in, 392, 392, 442 common species in, 397, 400, 400, 414 statistical data on populations in, 397 Cowbird, brown-headed, 467, 462, 492-3 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423; clover, 420, 421, 422; corn, 398; fallow fields, 4/5; forest, 432; hay, 417, 424; grassland, 413; marsh, 425; oats, 404, 405; orchard, 429; pasture, 409, 410; plowed fields, 403; shrubs, 424, 426, 427, 428, 454; small grain, 448; soy- beans, 402; urban residential areas, 436; wheat, 407, 449; woodland, 434 Creeper, brown, 460 as species in forest, 455; woodland, 392 Crow, common, 460, 462, 480—1 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421, 422; corn, 398, 400, 445, 446, 446; fallow fields, A — es October, 1963 Graper & GRABER: 415, 451; forest, 432, 435, 453, 455; grass- land, 413; hay, 417, 419, 453; marsh, 425; oats, 405; orchard, 429; pasture, 410, 450, 452; plowed fields, 403; shrubs, 426, 454; small grain, 443, 449; soybeans, 447; wheat, 407, 449; woodland, 392, 434 Cuckoo spp., 472 Cuckoo, black-billed, 459, 472 as species in forest, 433; plowed fields, 403 Cuckoo, yellow-billed, 459, 463, 472, 505 habitat preferences, 513 as species in corn, 399; fallow fields, 415; forest, 432; hay, #78; marsh, 425; orchard, 429; pasture, 410; shrubs, 426, 427; wheat, 407 411; pasture, D Dendrocopos spp. in forest, 433, 455; wood- land, 392, 434 Dickcissel, 462, 463, 495, 510 habitat preferences, 513 population for all habitats in study, 507 as species in alfalfa, 422, 423; clover, 420, 421, 422, 424; corn, 398; fallow fields, 414, 415; grassland, 4/3; hay, 389, 390, 416, 417, 418, 419; oats, #05; orchard, 429, 430; pasture, 409, 410; plowed fields, 403; shrubs, 426, 428; soybeans, 402; wheat, 406, 407, 408 Discussion, 500—15 Dove, mourning, 453, 459, 462, 469-72, 505, 508, 512 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423, 424; clover, #21, 422; corn, 392, 397, 398, 400, 445, 446, 446; fallow fields, 414, 475, 451; forest, 432, 435, 455; grassland, 4/3; hay, 417, tio, 724, $93; marsh, ¢25;- oats, 404, 405; orchard, 429, 430, 430; pasture, 410; plowed fields, 403; shrubs, 424, 426, 427, 428, 454; small grain, 448; soybeans, 401, 402, 447; urban residential areas, 436, se wheat, 406, 407, 408, 449; woodland, Dove, rock, 459, 463, 511 as species in commercial urban areas, 441; urban residential areas, 436, 437, 437 Drainage ditches, 479, 487, 490, 491, 492, 494, 495, 499 Duck, black, 459, 463 Duck, wood, 459, 463 E Eagle, bald, 459, 463 Eagle, golden, 459, 463 as species in forest, 455 Edge (edge shrub, road edge; see also Shrub habitat amd Shrub-grown area), 400, 412, 426, 428, 438, 445, 446, 452, 456, 464, 466, 467, 469, 471, 472, 473, 476, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 490, 491, 492, 493, 494, 495, 497, 498, 499, 502, 505, 506, 510, 511, 512 acreage in state, 442, 510 bird populations in, 442 Egret, common, 459, 463 as species in forest, 433; grasssland, 4/3 Biro PopuLaTions IN ILLINOIS On bo — Elm diseases, 511 Evolution, 501, 502, 503, 515 F Fallow fields, 412, 413-4, 424, 438, 438, 439, 439, 443, 444, 452, 456, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 479, 480, 482, 483, 484, 486, 487, 488, 490, #1, 492, 493, 494, 495, 496, 497, 498, 499, 4 ae censused, 396, 414, 415, 440, 443, 45 acreage in state, 388, 457 avifauna of, 4/5, 451 bird populations in, 440, 457 common species in, 4/4 statistical data on populations in, 4/4 Farm and crop acreage, various years, 502 Fencerow, 425, 510 Fertilizers, 514 Finch, purple, 462 habitat preferences, 514 as species in forest, #55; pasture, 450; shrubs, 454 Flicker, yellow-shafted, 460, 462, 473-4, 474, 475, 505, 511, 512 habitat preferences, 513, 514 population (statewide), 503 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421; corn, 398, 400, 445, 446; fallow fields, 415, 451; forest, 432, 436, 453, 455; grassland, 413; hay, 417, 419, 453; oats, 405; orchard, 429, 430, 430; pasture, 410, 450; plowed fields, 403, 447; shrubs, 427, 454; small grain, 448: urban residential areas, 436; wood- land, 392, 434 Flycatcher spp., 476, 477 Flycatcher, Acadian, 460, 476 range extension, 509 as species in forest, 432; woodland, 434 Flycatcher, great crested, #60, 463, 476, 511 habitat preferences, 513 as species in fallow fields, 4/5; forest, 432, 435, 436; hay, 418; orchard, 429, 430; pasture, 4/7; shrubs, 426, 427; urban resi- dential areas, 436; woodland, 434 Flycatcher, least, 460, 463 Flycatcher, Traill’s, 460, 476, 510 as species in corn, 398; hay, 4/3; marsh, 425; shrubs, 426 Flycatcher, yellow-bellied, 460, 463 Forbes-Gross method of censusing; see Census, strip Forbs, 412 Forest (see also Woodland), frontispiece, 383, 389, 393, 424, 430-6, 435, 437, 438, 438, 439, 439, 440, 443, 444, 445, 446, 453, 456, 457, 463, 464, 465, 466, 469, 470, 471, 472, 473, 474, 475, 476, 477, 479, 480, 481, 482, 483, 484, 485, 486, 488, 489, 490, 491, 492, 493, 494, 495, 499, 501, 502, 507, 509, 510, 511, 513, 514 ae acreage censused, 396, 431, 432-3, 443, 455 acreage in state, 388, 441, 457, 501, 502 avifauna of, 432-3, 455 bird populations in, 441, 457, 501-2 statistical data on populations in, 431 429 - orchard, 522 Ittinoris NATURAL History SURVEY BULLETIN G Gallinule, common, 459, 463 Garden crops (vegetables; see also Vegetable crops), 440 acreage censused, 396 acreage in state, 440, 456 bird populations in, 456 Gnatcatcher, blue-gray, 461, 463 : as species in forest, 432, 435; shrubs, 427; woodland, 434 Goldfinch, American, 462, 462, 495-6 habitat preferences, 513, 514 as species in alfalfa, 423; clover, 421, 422; corn, 398, 445, 446; fallow fields, 415, 451; forest, 432, 453, 455; grassland, 4/3; hay, 417, 453; marsh, 425; oats, 405; orchard, 429, 430; pasture, 410, 412, 450, 452; shrubs, 424, 426, 427, 428, 454; soybeans, 401, 402, 447; wheat, 449; woodland, 434 Goose, blue, 459, 463 Goose, Canada, 459, 463 3 as species in forest, 389, 455; soybeans, 44 ; wheat, 449 Grackle, common, 461, 462, 492, 509, 511 habitat preferences, 513 population for all habitats in study, 507 as species in alfalfa, 423; clover, 420, 421, 422; corn, 397, 398, 400; fallow fields, 414, 415; forest, 432; grassland, 4/3; hay, 417, 419, 424; marsh, 424, 425; oats, 404, 405; orchard, 429, 430; pasture, 409, 410, 450; plowed fields, 403; shrubs, 424, 426, 428; soybeans, 401, 402; urban residential areas, 436, 437, 437; wheat, 406, 407; woodland, 434 Grain crops (see also Small grain), 404 Grasslands, ungrazed (grasslands), frontis- piece, 412, 413, 414, 416, 418, 424, 438, 438, 439, 439, 440, 441, 449, 452, 464, 465, 466, 469, 470, 471, 473, 474, 475, 477, 478, 479, 480, 485, 486, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, 501, 502, 504, 506, 507, 508, 509, 513, 514 acreage censused, 396, 413 acreage in state, 388, 440 avifauna of, 413 bird populations in, 440 Grebe, horned, 459, 463 as species in marsh, 425 Grosbeak, blue, 462, 463 as species in forest, 433; shrubs, 427 Grosbeak, rose-breasted, 462 as species in corn, 399; forest, 433 Gull, herring, 459, 463 Gull, ring-billed, 459, 463 H eer preferences of common species, 5/3, a Habitat, summer bird populations in, 396—443 comparison of bird populations in, 437—40, 438, 439 statewide bird population estimate, 440-3 Habitat, winter bird populations in, 443-58 comparison of bird populations in, 453-6 statewide bird population estimate, 456-8 Vol. 28, Art. 3 Habitats and future of the avifauna, 509-15 in order of avifaunal variety, 509 in order of population densities, 509 Hawk spp. as species in corn, 445; fallow fields, 415; forests, 433, 455; hay, 453; pasture, 4/7, 450; plowed fields, 447; small grain, 448 Hawk, broad-winged, 459 Hawk, Cooper’s, 459, 463 as species in forest, 433 Hawk, marsh, 459 as species in corn, 446; pasture, 4/17, 450; shrubs, 454; wheat, 479 ‘Hawk, red-shouldered, 459 as species in corn, 399; forest, 433, 455; hay, 418; pasture, 450; plowed fields, 403 Hawk, red-tailed, 459, 463, 464—5 as species in corn, 399, 446; fallow fields, 451; forest, 432, 455; pasture, 411, 450; plowed fields, 403; shrubs, 426; small grain, 448; soybeans, 447; woodland, 434 Hawk, rough-legged, 459 as species in corn, 445; hay, 453; wheat, 449 Hawk, sparrow, 459, 462, 464, 465-6 habitat preferences, 514 as species in corn, 398, 445, 446; fallow fields, 475, 451; forest, 432, 455; hay, 417, 453; oats, 405; pasture, 410, 450; shrubs, uh 454; small grain, 448; wheat, 407, 49 Hay (hayfields), mixed (see also Hayfields), 414-8, 420, 422, 438, 438, 439, 439, 440, 441, 452, 465, 466, 468, 469, 471, 472, 473, 475, 476, 477, 479, 480, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 495, 496, 497, 499, 502, 504, 507, 508, 509, 510, 513, 514 acreage censused, 396, 416, 417-8, 443, 453 acreage in state, 388, 441, 457 avifauna of, 417-8, 453 bird populations in, 441, 457, 510 common species in, 419, 424 statistical data on populations in, 4/6 Hayfields (hay; see also Hay, mixed), 383, 386, 389, 390, 391, 391, 393, 404, 418, 420, 422, 438, 439, 443, 444 456, 466, 467, 468, 469, 470, 472, 473, 474, 476, 482, 484, 487, 489, 490, 491, 495, 497, 499, 504 Hedgerows (hedge), 428, 466, 467, 469, 471, 472, 473, 477, 479, 480, 483, 484, 485, 487, 491, 492, 493, 494, 495, 497, 498, 499, 505, 510 acreage censused, 396 acreage in state, 442 bird populations in, 442 Herbicides, 477, 485, 505, 514, 515 Heron, black-crowned night, 459 as species in corn, 399; marsh, 425; oats, 405; pasture, 411 Heron, great blue, 459 as ees in corn, 399; forest, 433; marsh, 42 Heron, green, 459, 463 as species in forest, 433; hay, 478; marsh, 425; pasture, 4/1 Heron, little blue, 459, 463 Highways, 442 acreage in state, 512 Se es ee all tite October, 1963 Graper & GRABER: Hummingbird, ruby-throated, 460 as species in clover, 427; forest, 432; hay, 4717; shrubs, 426; woodland, 434 Illinois, total land area, 440 Insecticides, 477, 479, 485, 504, 514, 515 J Jay, blue, 460, 462, 479-80, 480, 481, 504, 505, 512 habitat preferences, 513, 514 population for all habitats in study, 507 as species in clover, 421; corn, 398, 445; fal- low fields, 475, 451; forest, 432, 435, 436, 453, £55; grassland, 4/3; hay, 418, 453; oats, 05; orchard, 429, 430; pasture, 410, 450); shrubs, 426, 427, 454; urban residen- tial areas, 436; woodland, 392, 434 Junco, slate-colored, 462, 463, 497-8, 498 habitat preferences, 514 as species in corn, 445, 446, 446; fallow fields, 451, 452; forest, 453, 455; hay, 453; pasture, 450, 452; plowed fields, 447; shrubs, 453, 454; small grain, 448; soy- beans, 447; wheat, 449; woodland, 392 K Killdeer, 459, 462, 467-8 habitat preferences, 513 as species in alfalfa, 423; clover, 421; corn, 398, 400; fallow fields, 475; grassland, 413; hay, 417, 453; marsh, 425; oats, 405; pasture, 470; plowed fields, 401, 403; soy- beans, 402; wheat, 449 Kingbird, eastern, 460, 463, 476—7, 504, 505 habitat preferences, 5/3 as species in alfalfa, 423; clover, 421; corn, 398, 400; fallow fields, 415; forest, 433; hay, 417, 419; oats, 405; orchard, 429, 430; pasture, 4/0; plowed fields, 403; shrubs, 426, 428 Kingfisher, belted, #60 as species in corn, 399; forest, 432, 455; marsh, #25; pasture, 4/7; shrubs, 427 Kinglet, golden-crowned, #61 as species in forest, 455; woodland, 392 Kinglet, ruby-crowned, 461, 463 as species in shrubs, 454 L Lark, horned, 439, 457, 460, 462, 477-8, 500, D027, 2045095 513 habitat preferences, 513, 514 population (statewide), 504 population for all habitats in study, 507 as species in alfalfa, 423, 424; clover, #21, 422; corn, 392, 397, 398, 400, 400, 445, 445, 446, 447; fallow fields, 475, #51, 452; grassland, 413; hay, 417, 452, 453; oats, 405; pasture, 410, 450, 452; plowed fields, 401, 403, 447, 448, 456; shrubs, #27; soy- beans, 401, 402, 447, 448; small grain, 448, 449; wheat, 407, 449, 450 Legumes, 414, 416, 477, 510 Longspur, Lapland, 457, 462, 500 habitat preferences, 51/7 as species in corn, 392, 445, 446, 446; hay, Birp POPULATIONS IN ILLINOIS 523 452, 453; pasture, 450; plowed fields, 403, 447, 448, 456; soybeans, #47; small grain, 448, 449; wheat, 449, 450 Longspur, Smith’s, 462, 463 M Mallard, 459, 463 as species in forest, 455; marsh, 425 Man and the avifauna, 515 Man as dominant force of change, 515 Managed habitats development of, 502-3 specialization in, 504—6 Marsh (marshland; see also Wetlands), 385, 422-4, 438, 438, 439, 443, 463, 468, 469, 480, 484, 486, 487, 489, 490, 491, 492, 493, 495, 496, 499, 501, 502, 504, 509, 510, 513 acreage censused, 396, 425, 443 acreage in state, 3338, 441, 502, 510 avifauna of, 425 bird populations in, 441, 501-2, 510 Martin, purple, 460, 478, 503, 508 habitat preferences, 513 as species in corn, 398; fallow fields, 475; hay, #17; oats, #05; pasture, 410; soy- beans, 402; urban residential areas, #36, 437: wheat, 407 Meadowlark spp., 388, 389, 461, 462, 489—90, 508, 512 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423, 424; clover, 420, 421, 422, 424; corn, 398, 445, 446, 446; fal- low fields, 415, £51, 452; forest, 433, 455; grassland, 4/3; hay, 389, 390, 390, 416, 417, 418, 419, 424, 452, 453; marsh, 424, 425; oats, 405; pasture, 410, 411, 412, 450, 452; shrubs, 426, 428, 454; small grain, 448, 449, 450-1, 457; soybeans, #02, 447, 450; wheat, 407, 449, 450 Meadowlark, eastern, 388, 467, 489-90 as species in alfalfa, 422; clover, 420; fal- low fields, 414; grassland, 412; hay, 416, 4719; oats, 407; orchard, 429, 430, #30; pasture, 409; plowed fields, 403; wheat, 408 Meadowlark, western, 388, 461, 463, 489-90 range extension, 509 as species in clover, 420; grassland, 412; hay, 418 Melospiza spp. in fallow fields, 451; hay, 4/3; shrubs, 454 Mockingbird, 460, 483, 484, 505, 508 habitat preferences, 513, 514 range extension, 501, 509 as species in corn, 398, 400, 445; fallow fields, 415, #51; forest, 455; hay, 418; or- chard, 429, 430, 430; pasture, 410; plowed fields, #03; shrubs, 427, 454; soybeans, 402: urban residential areas, 436; wheat, 407, 449 N Nighthawk, common, #60, 512 ; as species in corn, 399; fallow fields, #75; hay, 4/7; orchard, 429; pasture, 4/1 Nuthatch, white-breasted, 460, 462 habitat preferences, 51+ 524 as species in corn, 445; forest, 432, 453, 455; pasture, 4/7, 450; shrubs, 454; woodland, 392 O Oats (oat fields), 401-7, 438, 438, 439, 448, 466, 469, 470, 473, 475, 477, 479, 480, 484, 485, 486, 488, 489, 490, 491, 492, 493, 495, 496, 497, 502, 509 acreage censused, 396, 404, 405 acreage in state, 388, 440 avifauna of, 405 bird populations in, 440, 442 common species in, 404 statistical data on populations in, 404 Open-field areas (habitat), 383, 386-7, 393, 400, 401, 414, 418, 424, 431, 433, 445, 446, 468, 469, 476, 477, 478, 479, 480, 487, 489, 494, 498, 510, 512 Orchard, 383, 385, 428, 429-30, 438, 438, 439, 439, 443, 466, 469, 470, 471, 472, 475, 476, 477, 479, 480, 481, 482, 483, 484, 485, 487, 488, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, 504, 506, 509, 512, 513, 514, 514 acreage censused, 396, 429, 443 acreage in state, 388, 441, 502, 511 avifauna of, 429 bird populations in, 441, 511 common species in, 430 Oriole, Baltimore, 461, 463, 509 as species in clover, 427; corn, 399; forest, 433; oats, 405; orchard, 429; pasture, 410; shrubs, 426 Oriole, orchard, 467, 463, 491—2, 504, 505, 509 habitat preferences, 5/3 population (statewide), 512 as species in clover, 421; corn, 398; fallow fields, 415; forest, 433; hay, 418; orchard, 429, 430, 430; pasture, 410; shrubs, 426, 427; wheat, 407 Ovenbird, 461, 463 as species in forest, 432, 436; woodland, 434 Owl, barred, 459 as species in forest, 433 Owl, great horned, 459, 463 as species in forest, 433, 455 Owl, long-eared, 459 as species in forest, 455; shrubs, 454 Owl, saw-whet, 460, 463 as species in shrubs, 454 Owl, short-eared, 460, 463 as species in corn, 446; fallow fields, 4517; small grain, 448 P Partridge, gray, 459, 463, 466 as species in clover, 427; shrubs, 426 Parus, 389 Pasture (pastureland), 393, 408-12, 408, 413, 418, 424, 438, 438, 439, 439, 441, 443, 444, 451-2, 452, 456, 464, 465, 466, 467, 468, 469, 470, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, 502, 504, 505, 510, 513, 514 acreage censused, 396, 409, 410-1, 443, 450 acreage in state, 388, 440, 457 avifauna of, 4170-1, 450 Intinois NATURAL History SURVEY BULLETIN Vol. 28, Art. 3 bird populations in, 440, 441, 457 common species in, 4/2 populations of breeding species in, 472 statistical data on populations in, 409 Pesticides, 514, 515 Pewee, eastern wood, 460, 463, 476 as species in forest, 432, 435; pasture, 411; shrubs, 426; urban residential areas, 436; woodland, 434 Pheasant, ring-necked, 383, 459, 463, 466 as species in alfalfa, 423; clover, 420, 421; corn, 392, 398, 446; fallow fields, 415, 451; forest, 433; hay, 391, 417, 453; marsh, 425; oats, 405; pasture, 417; small grain, 448; soybeans, 402; shrubs, 426 Phoebe, eastern, 460, 463, 476 as species in corn, 398; forest, 433; hay, 418; oats, 405; orchard, 429; pasture, 417; shrubs, 426 Pipit, Sprague’s, 467, 463 as species in hay, 453 Pipit, water, 467, 463 Plover, upland (see Upland plover) Plowed fields (plowed ground), 383, 401, 438, 439, 439, 440, 443, 444, 447, 448, 449, 452, 456, 468, 469, 470, 475, 477, 480, 482, 483, 486, 490, 495, 497, 500, 502, 509 acreage censused, 396, 403, 443, 447 acreage in state, 456 avifauna of, 403, 447 bird populations in, 456 common species in, 403, 414 Poa pratensis, 409 Population changes and latitude, 508 Population density and avifaunal 507-8 Population density in relation to size of census area, 391, 39] Prairie, frontispiece, 443, 468, 470, 495, 501-2, 504 variety, Quail (see Bobwhite) R Rail spp. in marsh, 425 Rail, king, 459 as species in marsh, 425 Rail, Virginia, 459, 463 as species in marsh, 425 Railroad rights-of-way, 412 Railroad tracks, 442, 512 Range extension of certain species (see also individual species), 508—9 Redstart, American, 467 as species in forest, 432; grassland, 4/3; shrubs, 426, 428; woodland, 434 Roadside (roadside shrubs), 425, 442, 464, 467, 472, 477, 478, 479, 486, 488, 510, 514 acreage in state, 512 Robin, 460, 462, 485-6, 504, 505, 508, 511 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421, 422; corn, 398, 400, 445, 446; fallow fields, 415, 451; forest, 432, 453, 455; grassland, 413; hay, 4/7; marsh, 425; oats, 405; orchard, 429, 430, 430; pasture, 410, 450; plowed October, 1963 GrapeR & GRABER: fields, 403; shrubs, 426, 427, 454; soybeans, 402; urban residential areas, #36, 437, 437; wheat, 407, 449; woodland, 434 Row-crop habitat (row crops), 438, 439, 440, 449, 452, 456, 468, 474, 477, 497, 502, 507, 509, 512 acreage in state, 440, 456 bird populations in, 440, 456 Rye, 440, 448, 470 acreage censused, 396 S Sandpiper, spotted, 459, 467 as species in corn, 398; marsh, 425; pasture, 411; soybeans, 402 Sapsucker, yellow-bellied, 460, 463, 473 as species in forest, 455 Savanna-like habitats, 408, 469, 473, 475, 476, 479, 503, 505, 505, 506, 506, 507, 508, 513 Scaup, lesser, 459, 463 Scientific names of birds, list of, 459-62 Sedges, 424 Shrike, loggerhead, 461, 462 as species in clover, #27; corn, 398, 445; fallow fields, 415, 451; hay, #138; oats, 405; orchard, 429; pasture, 410; plowed fields, 403; shrubs, 454; small grain, 443; soybeans, #02 Shrike, northern, 461, 463 Shrub (shrubby) habitat (see also Shrub- grown area and Edge), 386, 413, 429, 438, 439, 444, 445, 446, 457, 464, 466, 469, 470, 471, 474, 476, 477, 479, 480, 481, 483, 484, 485, 486, 487, 489, 490, 491, 493, 495, 496, 497, 498, 499, 501, 502, 505, 509, 510, 511, 512, 513, 514 acreage censused, 396 acreage in state, 338 Shrub-grown area or habitat (see also Shrub habitat amd Edge), 383, 424-8, 437, 438, 439, 443, 452-3, 456, 466, 469, 471, 472, 473, 474, 475, 476, 480, 482, 483, 484, 485, 486, 487, 491, 492, 493, 494, 495, 496, 497, 498, 499 acreage censused, 426-7, 443, 454 acreage in state, 441, 457 avifauna of, 426-7, 454 bird populations in, 441, 457, 510 common species in, 427, 428 Small grain, 386, 438, 439, 440, 443, 444, 4489, 451, 456, 466, 467, 468, 469, 471, 472, 474, 477, 478, 481, 487, 490, 491, 493, 495, 496, 497, 500, 502, 504, 509, 510, 513, 514 acreage censused, 396, 443, 448 acreage in state, 457 avifauna of, 448 bird populations in, 457 Snipe, common, 459, 463, 467 as species in marsh, 425 Sora, £59, 463 Soybean fields (soybeans; see also Beans), frontispiece, 383, 401, 401, 438, 4338, 439. 439, 440, 441, 443, 244, 447-8, 450, 456, 468, 469, 477, 479, 484, 488, 490, 491, 492, 495, 496, 497, 500, 514 acreage censused, 396, 402, 443, 447 acreage in state, 383, 440, 456 avifauna of, 402, 447 Birp PoPpuLaTIoNs IN ILLINOIS 525 bird populations in, 456 statistical data on populations in, 402 Sparrow spp. in small grain, 457 Sparrow, Bachman’s 462, 510 as species in fallow fields, 475; hay, 4/7; oats, 405; pasture, 4/7; shrubs, 427 Sparrow, chipping, 462, 498, 505 as species in clover, 422; corn, 398; fallow fields, 475; oats, 405; orchard, 429; pas- ture, 410; urban residential areas, 436 Sparrow, field, 462, 462, 498-9, 505 habitat preferences, 513, 514 population for all habitats in study, 507 as species in alfalfa, #23; clover, 421, 422; corn, 398; fallow fields, 414, 415, 451; forest, 432, 455; grassland, 4/3; hay, 417, 419; oats, 405; orchard, 429, 430, 430; pasture, 409, 4/0, 412, 412; plowed fields, 403; shrubs, 424, 425, 426, 427, 428, 454; soybeans, 402; wheat, 407; woodland, 434 Sparrow, fox, 462 as species in corn, #45; fallow fields, 45/7; forest, 455; pasture, 450; shrubs, 454 Sparrow, grasshopper, 462, 463, 496—7 habitat preferences, 513 as species in alfalfa, 423; clover, 420, #21, 422; corn, 399; fallow fields, 475; grass- land, 41/3; hay, 389, 390, 390, 416, 417, 419; oats, 405; orchard, 429; pasture, 410 ; shrubs, 427 ; soybeans, 402; wheat, 407, 408 Sparrow, Harris’, 462, 463 as species in shrubs, 454 Sparrow, Henslow’s, 462 as species in hay, 389, 390, 390, 417 Sparrow, house, 46/7, 462, 486, 488-9, 508, 511, 512 habitat preferences, 5/3, 514 population (statewide), 503 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421, #22, 424; commercial urban areas, 441; corn, 397, 398, 445, 446; fallow fields, 415, 451; forest, 433, 455; grassland, 413; hay, 417, 419, 453; oats, 405, 407; orchard, 429, 430, 430; pasture, 409, 410, 412, 450; plowed fields, 403, 447; shrubs, 426, 453, 454; small grain, 448; soybeans, 402, 447; ur- ban residential areas, 436, 437, 437; wheat, 406, 407, 449 Sparrow, lark, 462, 497, 505, 512 as species in clover, 422; corn, 398; fallow fields, 415; forest, 433; hay, #18; oats, 405; pasture, 410; plowed fields, #03; shrubs, 427; soybeans, 402; wheat, 407 Sparrow, Le Conte’s 462, 463 as species in fallow fields, 457; small grain, 448 Sparrow, savannah, 462, 496, 496 habitat preferences, 513 as species in alfalfa, 423; clover, 420, 421, 422, 424: corn, 446; fallow fields, 415; grassland, 413; hay, 417, 424; marsh, #25; oats, 405; pasture, 470, 412, 412; shrubs, 426, 428; small grain, 448; soybeans, 402, 447 Sparrow, song, #62, 463, 499-500, 508 habitat preferences, 513, 514 ; as species in clover, 421, 422; corn, 399, 44), 526 Intinors NATURAL History SurRvEY BULLETIN 446: fallow fields, 451, 452; forest, 432, 453, #55; grassland, #13; hay, 417, 453; marsh, 425; oats, 405; orchard, 429; pas- ture, 410, 450; shrubs, 426, 428, 454; small grain, 448; urban residential areas, 436; wheat, 407, 449 Sparrow, swamp, 462, 508 habitat preferences, 514 as species in alfalfa, 423; fallow fields, 457, 452; forest, 455; grassland, 413; hay, 417; marsh, #25; shrubs, 427, 454; small grain, 448 Sparrow, tree, 462, 463, 498 habitat preferences, 514 as species in corn, 392, 445, 446, 446; fallow fields, 451, 452; forest, 453, 455; hay, 453; pasture, #50, 452; plowed fields, 447; shrubs, 453, 454; small grain, 448, 449; wheat, 479, 450; woodland, 392 Sparrow, vesper, 462, 497 habitat preferences, 513 as species in alfalfa, 423, 424; clover, 421, 24; corn, 398, 400; hay, 417; oats, 405; orchard, 429; pasture, 470; shrubs, 426, 428; soybeans, 401, 402 Sparrow, white-crowned, 462, 463 habitat preferences, 5/4 as species in fallow fields, 457; shrubs, 454 Sparrow, white-throated, 462 habitat preferences, 5/4 as species in corn, 445; fallow fields, 457; forest, 55; shrubs, 454 Species annotated list of, 463—500 definition of common, 387 habitat preferences of common, 513, 514 Starling, 461, 463, 465, 473, 474, 475, 4867, SU eng Lt ea Wie habitat preferences, 513, 514 population (statewide), 503 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421, 422, 424; commercial urban areas, 441; corn, 398, 446; fallow fields, 4/5, 451; forest, 432, 455; grassland, 413; hay, 417, 453; marsh, #25; oats, 405; orchard, 429, 430; pasture, 410, 412, 450; plowed fields, 447; shrubs, 426, 453, 454; small grain, 448, 449; soybeans, 402; urban _ residential areas, 436, 437, 437; wheat, 407, 479; woodland, 434 Sturnella, 389 Sugar cane, 396 Swallow, bank, 460, 478 as species in grassland, 4/3; pasture, 410; shrubs, 426, 428 Swallow, barn, 460, 463, 478—9, 509 habitat preferences, 5/3 as species in alfalfa, 423; clover, 421, 422; corn, 398, 400, 400; fallow fields, 415; grassland, 413; hay, 417, 419; oats, 405; orchard, 429, 430, 430; pasture, 410, 412; shrubs, 427; soybeans, 402; wheat, 407 Swallow, cliff, 460, 478 as species in fallow fields, 475; oats, 405; shrubs, 427; wheat, 407 Swallow, rough-winged, 460, 463, 478 as species in clover, #21; fallow fields, Vol. 28, Art. 3 #15; marsh, 425; pasture, 4/1; wheat, 407 Swallow, tree, 460, 463, 478 as species in corn, 399; marsh, 425; pas- ture, 47] Swift, chimney, 460, 463, 472-3, 503 habitat preferences, 513 as species in alfalfa, 423; clover, 421, 422; corn, 398; fallow fields, 475; forest, 433; hay, 41/7, 419; oats, 405; orchard, 429; pasture, 470; plowed fields, 403; shrubs, 427; soybeans, #02; urban residential areas, 436, 437; wheat, 407 Tr Tables, types of, 388-9 Tanager, scarlet, 461 as species in forest, 433; shrubs, 427 Tanager, summer, 462 as species in clover, 4217; forest, 432, 435; pasture, 417; woodland, 434 Teal, blue-winged, 459, 463 as species in marsh, 425 Tern, black, 459, 463 as species in hay, 477; marsh, 425 Thrasher, brown, 460, 463, 484, 484-5, 505 habitat preferences, 513 population (statewide), 508 population for all habitats in study, 507 as species in alfalfa, 423; clover, 421, 422; corn, 398; fallow fields, 475; forest, 432, 436; hay, 417, 419; marsh, 425; oats, 405; orchard, 429, 430; pasture, 410; plowed fields, 403; shrubs, 424, 426, 428; urban residential areas, 436; wheat, 407; wood- land, 434 Thrush spp., 485 Thrush, hermit, 460, 463 as species in shrubs, 454, 455 Thrush, Swainson’s, 460, 463 Thrush, wood, 460, 485 as species in forest, 432, 435, #35, 436; shrubs, 426, 427; urban residential areas, 436; woodland, 434 Timothy, 416 acreage in state, 441 Titmouse, tufted, 460, 462, 482—3 habitat preferences, 513, 514 range extension, 509 as species in corn, #45, 446; forest, 432, 435, 453, 455; orchard, 429, 430, 430; pasture, 411; shrubs, 426, 427, 454; urban resident- ial areas, #36; wheat, #49; woodland, 392, 434 Towhee, rufous-sided, 462, 462 habitat preferences, 513 as species in corn, 398; fallow fields, 475; forest, 432, 435, 455; orchard, 429; pas- ture, 411; shrubs, 424, 426, 427, 454; urban residential areas, 436; woodland, 434 U Upland plover, 459, 463, 467, 468—9, 505, 506 habitat preferences, 5/3 as species in alfalfa, 423; corn, 398; clover, 421, 422; fallow fields, 415; hay, 417, 419; oats, 405; pasture, 410; plowed fields, 403; soybeans, 402; wheat, 407 ee eee October, 1963 GRABER & GRABER: BirD Urban residential areas (urban areas, resi- dential areas), 401, 424, 430, 436-7, 438, 438, 439, 439, 440, 443, 458, 466, 469, 470, 471, 472, 473, 475, 479, 480, 481, 482, 483, 484, 485, 487, 488, 489, 491, 492, 493, 494, 498, 502, 503, 504, 507, 508, 509, 511, 512, aise 515 acreage censused, 396, 436 acreage in state, 333, 441, 502, 511, avifauna of, 436 bird populations in, 441, 511, 512 common species in, 437 Urban commercial areas, bird populations in, 441 512 Vv Vegetable crops (see also Garden crops), 386 Vireo, Bell’s, 461, 463 range extension, 509 as species in pasture, 477; shrubs, 426, 427 Vireo, red-eyed, 393, 461, 463 as species in forest, 432, 435; pasture, 4/1; shrubs, 427; urban residential areas, 436; woodland, 434 Vireo, warbling, 461 as species in forest, 433; shrubs, 427; urban residential areas, 436 Vireo, white-eyed, #61 as species in forest, 432, 435; shrubs, 426; woodland, 434 Vireo, yellow-throated, 46/, 463 as species in forest, 433; woodland, 434 Vulture, black, 459, 463 as species in pasture, 450 Vulture, turkey, 459, 464, 483 habitat preferences, 5/4 range extension, 509 as species in corn, 398, 445; forest, 433, 455; hay, 478, 453; pasture, 4/7, 450; small grain, #48; soybeans, 402; wheat, 449 WwW Warbler spp., 487 Warbler, black and white, 46/ as species in forest, 433 Warbler, cerulean, 46/7, 463 as species in forest, 432; woodland, 434 Warbler, chestnut-sided, 467, 463 Warbler, hooded, 461, 463 as species in forest, 433 Warbler, Kentucky, 461, 463 as species in forest, 432, 435; shrubs, 427; woodland, 434 Warbler, magnolia, 461, 463 Warbler, myrtle, 46/ as species in forest, 455; shrubs, 454 Warbler, palm, 461, 463 Warbler, parula, 46/ as species in forest, 473; shrubs, 427 Warbler, pine, 461, 463 Warbler, prairie, 461, 463, 510 as species in shrubs, 426, 427 Warbler, prothonotary, 461 as species in forest, 432; shrubs, 427 Warbler, Swainson’s, 461, 463 Warbler, worm-eating, 461, 463 as species in forest, 432; woodland, 434 Warbler, yellow, 461 POPULATIONS IN ILLINOIS 327, as species in forest, 433; orchard, 429, 430: shrubs, 427 Warbler, yellow-throated, 461, 463 Waterthrush, Louisiana, 461 as species in forest, 433 Waxwing, cedar, 461, 463 as species in pasture, 450; shrubs, 454 Weather (climate), 384, 393-6, 394, 395, 442, 458, 464, 471, 478, 486, 498, 500, 508, 512 Weeds, 401, 413, 424, 449, 505 Wetlands (see also Marsh), 424, 501 Wheat (wheat fields), 407-8, 438, 438, 439, 439, 443, 444, 448, 449-51, 456, 466, 469, 470, 471, 472, 474, 475, 478, 479, 480, 484, 488, 490, 491, 492, 493, 494, 495, 496, 497, 499, 509, 514 acreage censused, 396, 406, 407, 443, 449 acreage in state, 338, 440, 457 avifauna of, 407, 449 bird populations in, 440, 442, 457 common species in, 406 statistical data on populations in, 406 Whip-poor-will, 460, 463 as species in forest, 433; shrubs, 427 Woodcock, American, 459, 463, 467 as species in pasture, 4// Woodland (woods, woody habitats; see also Forest), frontispiece, 386, 389, 393, 424, 431, 433, 436, 439, 440, 453, 456, 457, 464, 467, 476, 479, 481, 482, 483, 484, 491, 493, 494, 495, 498, 507, 511, 512 acreage in state, 441 bird populations in, 392, 392, 441 common species in, 434 Woodpecker, downy, 460, 462, 473, 475-6 habitat preferences, 513, 514 as species in corn, 399, 445, 446; fallow fields, 415, 451; forest, 432, 435, 453, 455; hay, 418, 453; pasture, 411, 450; plowed fields, 403; small grain, #483; shrubs, #26, 454: urban residential areas, 436; wood- land, 392, 434 Woodpecker, hairy, 460, 463, 473, +75, 503 habitat preferences, 514 as species in fallow fields, 451; forest, 432, 453, 455; pasture, 411, 450; shrubs, 454; woodland, 392, 434 Woodpecker, pileated, 460, 463, 473 as species in forest, 433, 455 Woodpecker, red-bellied, 460, 462, 473, 474, 503 habitat preferences, 5/4 range extension, 509 as species in corn, 445, 446; fallow fields, 451, 452; forest, #32, 453, 455; pasture, 411, #50; shrubs, #26, 454; small grain, 448; soybeans, 447 ; woodland, 392, 434 Woodpecker, red-headed, 460, 462, 473, 474-5, 505, 512 habitat preferences, 513, 514 population (statewide), 503 ‘ population for all habitats in study, 507 as species in clover, 421; corn, 398, 400, #45 ; fallow fields, 475; forest, 432, 436, 453, 455; grassland, 413; hay, 417, 419; oats, 405; orchard, 429, 430; pasture, #10; plowed fields, 403; shrubs, #26, 427; ur- ban residential areas, 436; wheat, #0/; woodland, 434 528 Ittrnors NaTuRAL History SURVEY BULLETIN Vol. 28, Art. 3 — Wren, Bewick’s, 460 Wren, short-billed marsh, 460 as species in corn, 399; fallow fields, 415; as species in grassland, 413; hay, 417; forest, 432; orchard, 429, 430; pasture, marsh, 425 #10; plowed fields, 403; shrubs, 426 Wren, winter, 460 Wren, Carolina, 460 as species in forest, 455 as species in corn, 399, 445, 446; fallow fields, 475, 451; forest, 432, 453, 455; or- ov chard, #29; pasture, #11; shrubs, 426, Yellowthroat, 461, 463, 487-8 427, #54; urban residential areas, 436; habitat preferences, 513 woodland, 392, 434 as species in alfalfa, 423; clover, 421; corn, Wren, house, 393, 460, 463 398; fallow fields, 415: forest, 432: hay habitat preferences, 513? #17; marsh, 425; oats, ‘405 : orchard, 429, as species in forest, 432; orchard, 429, 430, 430; pasture, 410: shrubs, 426, 427, 428; #30; pasture, 410; shrubs, 426; urban resi- wheat, 407 dential areas, 436; woodland, 434 Wren, long-billed marsh, 460, 463 as species in fallow fields, 4517; marsh, 425 Zonotrichia spp. in shrubs, 454 Some Publications of the ILLiNots NaturAL History SURVEY 7 a F BULLETIN Volume 27, Article 4—Food Habits of Migra- tory Ducks in Illinois. By Harry G. Ander- son. August, 1959. 56 pp., frontis., 18 figs., bibliog. 50 cents. Volume 27, Article 5.—Hook-and-Line Catch in Fertilized and Unfertilized Ponds. By Donald F. Hansen, George W. Bennett, Robert J. Webb, and John M. Lewis. August, 1960. 46 pp., frontis., 11 figs., bibliog. Single copies free to Illinois residents; 25 cents to others. Volume 27, 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., bibliog. $1.00. (Make check payable to University of Illi- nois; mail check and order to Room 279, Nat- ural Resources Building, Urbana, Tilioais:) Volume 28, Article 1—The Amphibians and Reptiles of Illinois. By Philip W. Smith. November, 1961. 298 pp., frontis., 252 figs., bibliog., index. $3.00. Volume 28, Article 2—The Fishes of Cham- paign County, Illinois, as Affected by 60 Years of Stream Changes. By R. Weldon Larimore and Philip W. Smith. March, 1963. 94 pp., frontis., 70 figs., bibliog., index. 50 cents. CIRCULAR 39.—How to Collect and Preserve Insects. By H. H. Ross. July, 1962. (Sixth printing, with alterations.) 71 pp., frontis., 79 figs. Single copies free to Illinois residents; 25 cents to others. 47.—Illinois Trees and Shrubs: Their Insect Enemies. By L. L. English. March, 1962. (Second printing, with revisions.) 92 pp., frontis., 59 figs., index. Single copies free to Illinois residents; 25 cents to others. 48.—Diseases of Wheat, Oats, Barley, and Rye. By G. H. Boewe. June, 1960. 159 pp., frontis., 56 figs. Single copies free to Illinois resi- dents; 25 cents to others. 49.—The Dunesland Heritage of Illinois. By Herbert H. Ross. (In cooperation with IIli- nois State Department of Conservation.) August, 1963. 28 pp. frontis, 16 figs., bibliog. BIOLOGICAL NOTES 38.—Ectoparasites of the Cottontail Rabbit in Lee County, Northern Illinois. By Lewis J. Stannard, Jr., and Lysle R. Pietsch. June, e 1958. 20 pp., 14 figs., bibliog. ae 39.—A Guide to Aging of Pheasant Embryos. By Ronald F. Labisky and James F. Opsahl. September, 1958. 4 pp., illus., bibliog. 40.—Night-Lighting: A Techaleue for Cap- turing Birds and Mammals. By Ronald F. Labisky. July, 1959. 12 pp., 8 figs., bibliog. 41—Hawks and Owls: Population Trends From Illinois Christmas Counts. By Richard R. Graber and Jack S. Golden. March, 1960. 4 24 pp., 24 figs., bibliog. 42.—Winter Foods of the Bobwhite in Southern ; Illinois. By Edward J. Larimer. May, 1960. 36 pp., 11 figs., bibliog. 43—Hot-Water and Chemical Treatment of — a Illinois-Grown Gladiolus Cormels. By J. L. Forsberg. March, 1961. 12 pp., 8 figs., bib- a liog. 44.—The Filmy Fern in Illinois. By Robert A. Evers. April, 1961. 15 pp., 13 figs., bibliog. 45.—Techniques for Determining Age of Rac- coons. By Glen C. Sanderson. August, 1961. 16 pp., 8 figs., bibliog. 46.—Hybridization Between Three Species of Sunfish (Lepomis). By William F. Childers © and George W. Bennett. November, 1961. — 15 pp., 6 figs., bibliog. 47.—Distribution and Abundance of Pheasants _ in Illinois. By Frederick Greeley, Ronald F. Labisky, and Stuart H. Mann. March, 1962. 16 pp., 16 figs., bibliog. 48.—Systemic Insecticide Pests of Trees and Shrubs—A Preliminary Report. By L. L. English and Walter Hart- stirn. August, 1962. 12 pp., 9 figs., bibliog. 49.—Characters of Age, Sex, and Sexual Ma- turity in Canada Geese. By Harold C. Han- — son. November, 1962. 15 pp., 13 figs., bibliog. — 50.—Some Unusual Natural Areas in Illinois — and a Few of Their Plants. Evers. July, 1963. 32 pp., 43 figs., bibliog. MANUAL 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. 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