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3  9999  06317  631  5 

57 


UNITED  STATES  DEPARTMENT  OF  THE  INTERIOR 

FISH  AND  WILDLIFE  SERVICE 


ATTWATER'S  PRAIRIE  CHICKEN 
ITS  LIFE  HISTORY  AND 

MANAGEMENT         ^^..^^ 


NORTH  AMERICAN  FAUNA  57 


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UNITED  STATES  DEPARTMENT  OF  THE  INTERIOR 

'Harold  L.  Ickes,  Secretary 

FISH  AND  WILDLIFE  SERVICE 
Ira  N.  Gabrielson,  Director 


North  American  Fauna  57 


ATTWATER'S  PRAIRIE  CHICKEN 

ITS  LIFE  HISTORY  AND 

MANAGEMENT 


BY 

VALGENE  W.  LEHMANN 


UNITED  STATES 

GOVERNMENT  PRINTING  OFFICE 

WASHINGTON  :  1941 


For  sale  by  the  Superintendent  of  Documents,  Washington,  D.  C.   -   -     -     -    Price  40  cents 


ABSTRACT 

ATTWATER'S  PRAIRIE  CHICKEN,  a  characteristic  bird  of  the  Texas 
coastal  prairie,  is  closely  related  to  the  now  extinct  heath-hen  of 
northeastern  North  America.  Once  abundant  in  an  area  extending  from  the 
coastal  tall-grass  prairies  of  southwestern  Louisiana  and  Texas  west  and  south 
to  near  Port  Isabel,  it  has  decreased  in  numbers  as  man  has  exploited  its 
habitat,  until  now  it  is  threatened  with  the  same  fate  as  that  of  the  heath-hen. 

Important  factors  limiting  the  numbers  of  the  bird  include  excessive  or 
persistent  rainfall  during  the  nesting  season,  heavy  grazing,  excessive  pasture 
burning,  agricultural  operations,  and  overshooting.  Management  will 
usually  involve  protection  from  excessive  killing,  improvement  of  food  and 
cover,  and  control  of  predators  and  of  the  kill  by  hunters.  Responsibility 
for  this  rests  with  the  landowner. 

Optimum  prairie  chicken  range  apparently  consists  of  well-drained  grass- 
land, with  some  weeds  or  shrixbs,  the  cover  varying  in  density  from  light  to 
heavy;  and  with  surface  water  available  in  summer;  diversification  within 
the  grassland  type  is  essential.  In  the  absence  of  ample  refuges  for  the 
species,  probably  all  other  favorable  factors  together  will  fail  to  save 
Attwater's  prairie  chicken  from  extinction. 

This  number  continues  the  series  of  the  North  American  Fauna  issued  by 
the  Bureau  of  Biological  Survey,  of  the  United  States  Department  of  Agri- 
culture, prior  to  its  transfer  and  consolidation  with  the  Bureau  of  Fisheries 
on  June  30,  1940,  to  form  the  Fish  and  Wildlife  Service,  in  the  Department 
of  the  Interior. 


CONTENTS 

Page 

Introduction 1 

Former  distribution  of  prairie  chickens  in  Texas 2 

Differences  between  Attwater's  and  the  other  prairie  chickens 4 

Attwater's  prairie  chicken 4 

Lesser  prairie  chicken 5 

Former  abundance  of  Attwater's  prairie  chickens 6 

Present  distribution  and  numbers 7 

Habits 10 

Courtship  and  mating 10 

Nesting 14 

Growth  and  development  of  young 16 

Brood  size 18 

Juvenile  mortality 19 

Family  disintegration 19 

Annual  increase 20 

Flocking 20 

Seasonal  movements 21 

Spring 21 

Summer 22 

Fall  and  winter 24 

Food 25 

Habitat  requirements 30 

Kind  of  environment  best  suited 30 

Character  and  density  of  vegetation 30 

Topography 30 

Water 31 

Seasons  of  scarcity 31 

Limiting  factors 31 

Natural  factors 32 

Rainfall  during  the  nesting  season 32 

Floods 35 

Drought 35 

Hurricanes 35 

Hail 35 

Local  storms 36 

Disease 36 

Spread  of  woody  vegetation 36 

Predation 37 

Nests 37 

Young 38 

Adults 39 

Review  of  natural  factors 40 

Artificial  factors 40 

Agriculture 40 

Pasture  burning 41 

in 


IV  CONTENTS 

Limiting  factors — Continued. 

Artificial  factors — Continued.  Page 

Overgrazing 42 

Oil  development 43 

Drainage 43 

Pasture  mowing 43 

Mechanical  accidents 44 

H  anting 44 

Management 45 

Protection 45 

Habitat  improvement 46 

Evaluating  conditions 47 

Census  methods 47 

Spring  counts  on  the  courtship  grounds 47 

Rope  count 49 

Car-dog  count 52 

Using  the  census 52 

Spring 53 

Summer 54 

Winter 55 

General  recommendations  for  habitat  control 56 

Predator  control 57 

Harvesting  the  surplus 57 

Restocking 58 

Summary 59 

Literature  cited 62 

Index 65 


ILLUSTRATIONS 


Plate  Facing  page 

1.  Attwater's  prairie  chickens  (Tympanuchus  cupido  attwateri)  on  boom- 

ing ground Frontispiece 

2.  Dense  cordgrass  areas  in  Aransas  County,  Tex 4 

3.  Male  Attwater's  prairie  chicken,  showing  vocal  sacs 10 

4.  Nest  and  eggs  of  Attwater's  prairie  chicken;  Colorado  County,  Tex__         14 

5.  Concealment  of  nests  by  Attwater's  prairie  chicken;  Colorado  County, 

Tex 15 

6.  Chicks  of  Attwater's  prairie  chicken;  Colorado  County,  Tex 16 

7.  Wild  indigo  (Baptisia)  in   a  closely  grazed  pasture;  Austin  County, 

Tex 22 

8.  Diversified  cover — excellent  prairie  chicken  range;  Colorado  County, 

Tex 30 

9.  Medium-heavy  to  heavy  cover — excellent  food-cover  conditions  in  a 

moderately  grazed  pasture;  Colorado  County,  Tex 31 

10.  Shells  of  eggs  at  prairie  chicken  nest  destroyed  by  house  cat;  Colorado 

County,  Tex 38 

11.  Native  bluestem  prairie — well  populated  by  prairie  chickens;  Colorado 

County,  Tex 39 

12.  Excellent  unburn ed  cover  at  right  of  road;  inferior  burned  cover  at 

left;  Colorado  County,  Tex 42 

13.  Rope  counting  of  prairie  chickens  on  Matagorda  Island,  Tex 48 

14.  Fenced  plot  planted  to  hegari;  Wharton  County,  Tex 56 

FiGDHB  Page 

1.  Distribution  of  Attwater's  prairie  chickens  in  Texas 3 

2.  Movements  of  a  combined  brood,  Colorado  County,  Tex 23 

3.  Rainfall  conditions  in  May  in  the  range  of  Attwater's  prairie  chicken  in 

Texas Facing  page        34 

4.  Diagram  of  the  rope  count 50 

V 


ATTWATER'S  PRAIRIE  CHICKEN 

By  Valgene  W.  Lehmann 
Collaiorator,  Division  of  Wildlife  Research,  Fish  and  Wildlife  Service^ 


INTRODUCTION 

Attwater's  prairie  chicken  {Tympanuchus  cupido  atticateri  Ben- 
dire)  (see  frontispiece),  might  well  be  called  the  heath-hen  of  the 
South.  It  is  so  closely  related  to  the  now  extinct  heath-hen  {T.  c. 
cupido)  of  northeastern  North  America  as  to  be  classified  in  the 
same  species.  Like  the  heath-hen,  Attwater's  prairie  chicken  once 
inhabited  a  large  area,  its  former  range  including  the  coastal  tall- 
grass  (Andropogon)  prairies  of  southwestern  Louisiana  and  in  Texas 
west  and  south  to  Cameron  County,  near  Port  Isabel.  In  certain 
areas  the  birds  were  abundant.  Old-timers  report  that  the  deep 
booming  courtship  calls  of  the  males  once  reverberated  from  the 
prairies  with  such  force  and  monotony  as  actually  to  pain  sensitive 
eardrums.  The  bird,  however,  is  no  longer  abundant.  It  has  de- 
creased in  numbers  as  man  has  exploited  its  habitat  until  now  it  is 
threatened  with  the  fate  of  the  heath-hen — extinction. 

In  his  "Biological  Survey  of  Texas"  Vernon  Bailey  (1905:  19)' 
places  Attwater's  prairie  chicken  at  the  head  of  the  list  of  breeding 
birds  of  the  Texas  coastal  prairie.  In  addition  to  being  a  character- 
istic bird  of  the  region,  this  prairie  chicken  is  probably  the  most 
popular  species  wherever  found.  Most  people  who  know  it  have  a 
genuine  appreciation  of  its  color  and  charm.  Rare  indeed  is  the 
person  who  finds  no  esthetic  stimulus  in  the  sight  of  a  strutting 
male  on  the  booming  ground,  or  a  brood  of  downy  chicks  on  the  edge 
of  a  short-grass  flat.  Both  ranchmen  and  farmers  highly  appreciate 
the  prairie  chicken's  appetite  for  grasshoppers,  salt-marsh  cater- 
pillars {Estigmene  acraea)^  and  the  moths  of  the  cotton  leaf  worm 
{Alabama  argillacea).  Under  proper  conditions  prairie  chicken 
hunting  provides  a  high  type  of  sport,  and  the  flesh  of  the  birds, 
especially  that  of  the  young,  is  highly  esteemed  as  food. 


1  Cooperative  contribution  from  the  Texas  Cooperative  Wildlife  Research  Unit,  estab- 
lished by  the  Agricultural  and  Mechanical  College  of  Texas  ;  the  Texas  Game,  Pish,  and 
Oyster  Commission ;  the  American  Wildlife  Institute ;  and  the  Fish  and  Wildlife  Service. 

*  Publications  referred  to  parenthetically  by  date  (alone  or  followed  by  colon  and  specific 
page)  are  listed  in  the  Literature  Cited,  p.  62. 

Explanation  of  Fkontispiecb 

Attwater's  prairie  chickens  (Tympanuchus  cupido 
attwateri)  on  booming  ground 


2  NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

The  real  appeal  of  the  prairie  chicken,  however,  lies  in  its  con- 
nection with  the  colorful  and  eventful  early  days  in  Texas.  The 
prairie  hen  summons  memories ;  it  prompts  old-timers  to  recall  when 
the  range  was  free  of  wire  fences  and  oil  derricks,  and  rich  grasses 
grew  waist  high.  Thoughtful  people  deplore  the  passing  of  Att- 
wat^r's  prairie  chicken,  one  of  the  last  landmarks  of  the  prairie  as 
it  used  to  be.  Highly  appropriate  was  the  selection  of  this  bird  as 
a  species  of  major  interest  by  the  Texas  Cooperative  Wildlife  Ke- 
search  unit.' 

FORMER  DISTRIBUTION  OF  PRAIRIE  CHICKENS  IN  TEXAS 

H.  C.  Oberholser,  in  a  letter  to  the  present  writer,  states  that  in 
his  opinion  prairie  chickens  once  occurred  at  some  time  of  year  on 
most  prairie  areas  in  Texas.  In  the  main  it  appears  that  the  differ- 
ent kinds  of  prairie  chickens  in  the  State  occupied  separate  ranges, 
and  that  mixing  and  intergradation  were  confined  largely  to  marginal 
areas. 

The  principal  former  range  of  the  greater  prairie  chicken  in  Texas, 
as  indicated  by  the  records  of  F.  M.  Bailey  (1927:  130),  Gross  (Bent 
1932:  262),  Strecker  (1927:  321),  and  old  residents  with  whom  the 
writer  has  conferred,  was  northeastern  Texas  southwest  to  the  vicin- 
ity of  Waco.  Likewise,  records  show  that  the  lesser  prairie  chicken 
was  indigenous  to  northwestern  Texas  and  the  high  plains  region 
in  winter  to  about  Bandera  and  westward  through  the  "hill  country" 
to  the  arid  plains  west  of  the  Pecos  River  (Bendire  1892:  355,  and 
others).  Attwater's  prairie  chicken,  it  appears,  was  largely  confined 
to  the  better-drained  prairies  of  western  Louisiana  and  Southeastern 
Texas  (fig.  1,  p.  3). 

According  to  Oberholser  (1938:  190-191)  the  eastern  limit  of  the 
range  of  Attwater's  prairie  chicken  was  in  the  vicinity  of  Abbeville, 

*  So  many  persons  have  assisted  in  the  prairie  chicken  studies  that  it  is  impossible  to 
list  them  all.  General  supervision  of  the  work  was  by  Walter  P.  Taylor,  leader  of  the 
Texas  Cooperative  Wildlife  Research  Unit,  College  Station,  Tex.  Valuable  editorial 
suggestions  were  received  from  W.  B.  Davis,  professor  of  wild  game.  School  of  Agriculture, 
Agricultural  and  Mechanical  College  of  Texas;  and  from  William  J.  Tucker,  executive 
secretary,  Texas  Game,  Fish,  and  Oyster  Commission.  The  bulk  of  examinations  of  crops, 
gizzards,  and  scats  was  done  by  Clarence  Cottam,  Clarence  F.  Smith,  and  their  associates 
in  the  Section  of  Food  Habits,  Division  of  Wildlife  Research,  Fish  and  Wildlife  Service. 

In  his  field  work  in  1938  the  writer  was  assisted  by  H.  R.  Siegler,  field  biologist  of  the 
Research  Unit.  Many  Colorado  County  landowners  cooperated ;  among  these,  M.  C. 
Shindler,  Emil  Gleuck,  Ed  Koy,  Adolf  Renz,  and  I.  V.  Duncan  deserve  special  mention. 
E.  P.  Haddon,  photographer  of  the  Texas  Commission,  took  some  of  the  photographs  here 
reproduced.  The  assistance  of  the  State  game  wardens  was  indispensable.  Deserving 
of  special  mention  are  T.  S.  Boothe,  Beaumont ;  J.  C.  Gardner,  Hull ;  R.  Z.  Cowart,  Rosen- 
berg; Ed  McCloskey,  Victoria;  C.  D.  Tidwell,  Bay  City;  G.  P.  Ferguson,  Sinton ;  and 
T.  T.  Waddell,  Eagle  Lake.  Waddell's  contributions  to  the  study  were  outstanding;  he 
gave  most  generously  of  his  time,  records,  and  extensive  experience.  To  him,  and  to  all 
others,  the  writer  is  deeply  grateful. 


ATTWATER'S  PRAIRIE    CHICKEN 


Opelousas,  and  Bayou  Teche  in  Louisiana.  There  are  no  authentic 
records  of  the  occurrence  of  any  species  of  prairie  chicken  in  Texas 
south  of  northern  Aransas  County,  except  for  one  bird  reported 
from  near  Brownsville  by  Merrill  (1879:  159-160).  Prairie  chickens 
did  not  occur  near  San  Antonio,  Tex.,  in  1890,  for  Babbitt,  in  Bendire 
(1894:  130)  wrote  as  follows:  "The  prairie  hen  is  not  found  in  the 


LEGEND 

Probable    Former    Ranqe 
Prcaenf    Pange 


Figure  1.— Present   distribution   of  Attwater's   prairie   chicken   in   Texas  and 
probable   former   range  in   the   coastal   section. 

immediate  vicinity  of  San  Antonio,  Tex.,  but  exists  in  great  numbers 
south  and  southeast  from  here,  all  at  an  average  distance  of  100 
miles.  *  *  *"  Simmons  (1925:  82)  submits  the  records  of  O. 
Brinkman  and  C.  D.  Oldright  as  evidence  that  Attwater's  prairie 
chicken  occurred  as  a  breeding  bird  in  the  vicinity  of  Austin.  Travis 


4         NORTH  AMERICAN   FAUNA   57,   FISH  AND   WILDLIFE    SERVICE 

County,  and  in  Williamson  County  as  late  as  1878,  but  the  accuracy 
of  the  data  is  questionable.  Apparently  the  limit  was  the  northern 
edge  of  the  coastal  prairie. 

Roughly,  the  territory  occupied  by  Attwater's  prairie  chicken  was 
south  of  a  line  extending  northeast  from  Refugio  through  Fannin, 
Thomaston,  Provident  City,  Rock  Island,  Industry,  Welcome,  Bell- 
ville,  Prairie  View,  Tom  Ball,  Humble,  Liberty,  Devers,  Cheek,  and 
Orange.  All  this  area  of  approximately  8,500,000  acres  in  coastal 
Texas,  however,  was  not  occupied.  Deciduous  woodlands  near  rivers, 
as  along  the  San  Antonio,  Guadalupe,  Colorado,  Brazos,  and 
Trinity,  were  used  only  to  a  limited  extent  and  only  along  the  mar- 
gins. Prairie  chickens  did  not  occupy  the  pine  forests  in  Harris 
County  and  to  the  east  or  the  thick  mesquite-acacia  brush  that  oc- 
curred in  considerable  stands  in  Calhoun  and  other  western  counties 
as  much  as  100  years  ago.  Brackish  and  salt-water  marshes  in  Or- 
ange, Jefferson,  and  Chambers,  and  less  widely  in  other  counties 
to  the  west,  and  extensive  cordgrass  {Spartina  spartinae)  flats  (pi.  2) 
in  Aransas  County  and  elsewhere  in  low  country  bordering  the  Gulf, 
probably  always  were  little  used  by  chickens  except  to  a  limited 
extent  in  winter.  There  were,  however,  about  6,000,000  acres  of 
bluestem  prairie  that  probably  supported  many  prairie  chickens  in 
favorable  years. 

DIFFERENCES  BETWEEN  ATTWATER'S  AND  THE  OTHER  PRAIRIE 

CHICKENS 

During  the  nineteenth  century  three  kinds  of  prairie  chickens  oc- 
curred in  Texas:  the  greater  prairie  chicken  {Tympanuchus  cupido 
americanus  Reichenbach),  Attwater's  prairie  chicken  {T.  c.  attioateri 
Bendire),  and  the  lesser  prairie  chicken  {T.  pallidicinctus  Ridg- 
way).  Differences  between  the  greater  and  Attwater's  prairie  chick- 
ens are  slight;  the  lesser  prairie  chicken  is  somewhat  better 
characterized. 

ATTWATER'S  PRAIRIE  CHICKEN 

Bendire   (1894:  130)   described  Attwater's  prairie  chicken  as — 

Smaller  than  T.  americanus  [greater  prairie  chicken],  darker  in  color,  more 
tawny  above,  usually  with  more  pronounced  chestnut  on  the  neck ;  smaller 
and  more  tawny  light  colored  spots  on  the  wing  coverts,  and  much  more 
scantily  feathered  tarsus,  the  latter  never  feathered  down  to  the  base  of 
toes,  even  in  front;  a  broad  posterior  strip  of  bare  skin  being  always  exposed, 
even  in  winter,  while  in  sximmer  much  of  the  greater  part  of  the  tarsus  is 
naked. 

In  weight  Attwater's  prairie  chicken,  however,  is  not  perceptibly 
lighter  than  the  greater  prairie  chicken.  The  average  of  10  males 
(33.11  ounces,  as  shown  in  table  1,  p.  5)  exceeded  by  2.11  ounces 
the  average  weight  of  the  greater  prairie  chicken   (31  ounces),  as 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


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ATTWATER'S   PRAIRIE    CHICKEN 


given  by  Gross  (1930a:  40).  The  average  weight  of  six  females 
(25.7  ounces)  was  only  0.6  ounce  less  than  that  of  the  female  greater 
prairie  chicken  (26.3  ounces),  according  to  the  same  authority  (loc. 
cit.).  The  weight  of  Attwater's  prairie  chickens,  especially  that  of 
males,  varies  perceptibly  from  season  to  season ;  three  males  obtained 
at  the  beginning  of  the  courtship  season  were  appreciably  heavier 
(about  7.5  ounces)  than  those  collected  at  other  times.  Darkness  of 
color,  tawniness  above,  and  the  amount  of  chestnut  on  the  neck  are 
other  characters  that  vary  greatly  both  seasonally  and  individually. 
Winter  specimens  are  generally  lighter  in  color  than  those  collected 
in  spring;  they  have  comparatively  little  chestnut  on  necks  and 
backs.  The  feathering  on  the  tarsus  also  varies  with  the  season ;  the 
legs  of  specimens  collected  in  winter  are  well  feathered  to  the  base 
of  the  toes.  The  style  of  barring  on  the  back  and  rump,  according 
to  F.  M.  Bailey  (1927:  130),  is  the  same  for  both  subspecies,  that  is, 
the  bars  are  single,  broad,  and  solid  black.  Altogether,  physical 
differences  between  Attwater's  and  the  greater  prairie  chicken  are 
minor  and  insufficient  to  allow  accurate  field  identification.  In  a 
series  of  skins,  however,  the  smaller  measurements  of  wing,  tail,  bill, 
and  total  length  and  the  differences  in  general  ruddiness  and  buffiness 
of  the  underparts  are  characteristic  and  serve  to  separate  Attwater's 
prairie  chicken  as  a  subspecies. 

Tabui:  1. — Weights  of  16  Attwater's  prairie  chickens 


County 

Date  collected 

Weight  I 

County 

Date  collected 

Weight  1 

Grams 

Ounces 

Grams 

Ounces 

MALES 

Colorado 

Do - 

Apr.  17, 1939  2 
Sept.   1,1937  3 
Sept.   4,1937' 
Oct.    23,1937 
Nov.    3,1937 

Jan.      6, 1938 
Jan.    27,1938 
Feb.   14,1938 

1, 135. 20 
682.  00 
590. 07 
760.20 
874. 00 

723.  69 
715.24 
726.80 

40.03 
24.05 
20.81 
26.81 
30.82 

25.18 
25.22 
25.63 

MALES 

Refugio 

Do 

Colorado 

Feb.  15,1938 

do 

Mar.  18, 1938 
Apr.   10, 1938  < 
July    26,1938 

Feb.   15,1938 
Aug.  20,1938 
Aug.  23,1938 

1, 103.  70 
1, 125.  20 
1,120.45 
1, 077.  26 
921.  34 

785.  60 
722.  89 
708.  72 

38.92 
39  68 

Do.- 

39  51 

Do 

38.00 

Do 

Colorado 

FEMALES 

Refugio 

Colorado 

Do 

32  50 

FEMALES 

Colorado 

Do - 

27.70 
25.50 

Austin- 

25.00 

1  Average  weights:  Males,  938.94  gm.  (33.11  oz.);  females,  730.49  gm.  (25. 70  oz.). 

'  Taken  from  hawk. 

'  Immature  bird. 

*  Taken  from  poacher. 

LESSER  PRAIRIE  CHICKEN 

The  lesser  prairie  chicken  is  somewhat  smaller  than  either  of  its 
relatives.  Verne  E.  Davison,  in  a  letter,  reports  that  20  mature  males 
from  Oklahoma  weighed  23.50  to  31.50  ounces  and  averaged  27.56 
ounces.  Five  hens  weighed  23.75  to  27.50  ounces  and  averaged 
25.55  ounces.  In  other  words,  these  male  lesser  prairie  chickens  were, 
on  the  average,  3.44  ounces  lighter  than  the  male  greater  prairie 
chickens  (31  ounces)  weighed  by  Gross  (1930a:  40);  these  female 


6         NORTH  AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

lesser  prairie  chickens  weighed  0.55  ounces  less  than  the  female 
greater  prairie  chickens  that  Gross  obtained.  According  to  Bailey 
(1927:  131),  the  general  coloration  of  the  lesser  prairie  chicken  is 
paler  than  that  of  either  the  greater  or  Attwater's,  and  the  color 
and  arrangement  of  the  bars  on  back  and  neck  also  differ.  Wliereas 
the  bars  are  single,  broad,  and  solid  black  in  both  the  greater  and 
Attwater's  forms,  they  are  treble,  a  broad  brown  bar  enclosed  by 
two  narrow  black  ones,  in  the  lesser  species. 

FORMER  ABUNDANCE  OF  ATTWATER'S  PRAIRIE  CHICKEN 

Accurate  information  as  to  the  former  abundance  of  Attwater's 
prairie  chicken  is  difficult  to  obtain,  although  the  data  at  hand 
record  their  numbers  in  certain  areas.  Many  old  cattlemen  of  the 
coastal  prairie  have  told  the  writer  that  in  early  days  the  prairie 
chickens  were  relied  upon  to  furnish  fresh  meat  for  the  cattle  camps. 
The  task  of  killing  40  or  50  prairie  chickens  was  menial,  the  cook  of 
the  outfit  usually  attending  to  it. 

In  the  Eagle  Lake  area,  Colorado  County,  not  more  than  35  years 
ago,  prairie  chickens  were  shot  as  clay  pigeons  are  today.  On  ap- 
pointed occasions  parties  of  10  to  20  or  more  men  encamped  in  the 
sandhill  country  along  the  Bernard  River  and  hunted  the  birds  for 
periods  varying  from  a  few  days  to  a  week  or  more.  At  the  end 
of  each  day  the  chickens  killed,  or  their  heads,  were  tallied.  At  the 
end  of  the  encampment  period  the  party  having  killed  the  smallest 
number  paid  the  expenses  of  the  outing.  Waddell  and  others  state 
that  10  or  more  piles  of  prairie  chickens,  each  containing  upwards 
of  100  birds,  usually  were  left  at  the  camp  sites  to  rot  or  to  be  eaten 
by  vultures.  These  encampments  began  about  July  4  and  continued 
through  fall  and  winter. 

During  the  summer  of  1893  or  1894,  in  Matagorda  County,  near 
Bay  City,  V.  L.  LeTulle  reports  that  71  Attwater's  prairie  chickens 
were  shot  in  2  hours;  and  that  in  1895,  at  the  site  of  the  present  town 
of  Van  Vleck,  he  and  3  friends  killed  72  birds  in  an  afternoon,  and 
except  for  poor  marksmanship  would  have  bagged  many  more. 
Near  Wharton,  in  Wharton  County,  in  the  fall  of  1894  or  1895, 
LeTulle  found  340  piled  where  hunters  had  camped. 

Mendell  Burrell  of  the  Ray  Pipkin  ranch  (Big  Hill  country, 
Jefferson  County)  told  the  writer  that  as  late  as  1920  his  domestic 
chickens  were  fed  under  the  ranch  house  in  winter  to  prevent  prairie 
chickens  from  consuming  the  grain.  In  the  same  area  it  is  said  that 
flocks  of  from  150  to  200  Attwater's  prairie  chickens  often  alighted 
in  the  introduced  chinaberry  trees  {Melia  azedarach  vmbraeulifera) 
around  the  ranch  houses  and  fed  extensively  on  the  berries.  In 
verification  of  this  statement  W.  S.  Boothe,  State  game  warden  at 


ATTWATER'S    PRAIRIE    CHICKEN  7 

Beaumont,  Tex.,  presented  the  writer  with  a  photograph,  taken  in 
1910  on  the  White  Ranch  at  Devers,  showing  a  dozen  prairie  chickens 
in  a  chinaberry  tree  beside  a  house. 

C.  H.  Brosig,  who  hunted  Attwater's  prairie  chickens  in  the  Eagle 
Lake  area  for  more  than  40  years,  reported  that  the  birds  once 
were  so  numerous  in  the  sandhill  country  bordering  the  Bernard 
River  that  a  new  covey  frequently  was  flushed  while  singles  from 
one  previously  discovered  were  being  pursued.  Paul  Mundelius  noted 
a  similar  high  density  in  concentrations  of  prairie  chicken^  in  the 
Sealy-San  Felipe  section  in  the  eastern  part  of  Austin  County  in 
1873-75.  These  conditions  are  seldom  found  on  areas  where  the  pop- 
ulation is  less  than  one  bird  to  an  acre,  and  they  show  the  former 
abundance  of  Attwater's  prairie  chickens  in  favorable  areas.  Not 
all  the  coastal  bluestem  {Andropogon)  prairie,  about  6,000,000  acres, 
wag  equally  favorable  for  prairie  chickens  even  under  pristine  con- 
ditions; well-drained,  well-populated  country  (one  bird  to  an  acre), 
as  along  the  Bernard  River,  did  not  aggregate  more  than  900,000 
acres,  or  about  15  percent  of  the  inhabited  range.  A  little  more  than 
half,  3,300,000  acres,  or  55  percent,  of  the  prairie  country  was  only 
fairly  well  drained ;  these  areas,  protected  for  periods  up  to  17  years, 
now  have  a  maximum  population  of  about  one  bird  to  each  10  acres. 
Approximately  1,800,000  acres,  or  30  percent,  was  poorly  drained; 
prohibition  of  hunting  for  periods  up  to  15  years  has  not  produced 
a  population  in  excess  of  one  bird  to  each  50  acres  on  certain  of 
these  large  ranches.  Probably,  therefore,  the  former  abundance  of 
Attwater'g  prairie  chicken  in  Texas  approached,  but  seldom  if  ever 
attained  or  exceeded,  1,000,000  individuals,  even  in  peak  years. 

PRESENT  DISTRIBUTION  AND  NUMBERS 

Data  on  the  present  status  of  Attwater's  prairie  chicken  (table  2, 
p.  8)  were  obtained  as  follows: 

At  least  90  percent  of  all  farms  and  ranches  known  or  thought 
to  have  been  occupied  by  the  birds  in  1937  were  visited  by  the  writer 
in  company  with  local  State  game  wardens.  Unless  the  warden  was 
thoroughly  familiar  with  conditions  on  the  various  areas,  conference^ 
were  held  with  landowners,  managers,  cowboys,  guides,  hunters,  or 
other  persons  who  were  in  position  to  know  the  status  of  prairie 
chickens  on  particular  tracts.  After  the  conferences  a  general  recon- 
naissance of  the  areas  wa^  made  by  automobile  or  on  horseback,  and 
notes  were  taken  on  the  topography,  vegetation,  surface  water,  and 
soil  to  ascertain  the  general  suitability  of  the  land  for  prairie  chickens, 
as  was  done  in  similar  studies  previously  made  in  the  Eagle  Lake  area. 

Then  in  the  light  of  all  available  information  the  range  of  Att- 
water's prairie  chicken  was  mapped  in  each  county,  and  representa- 


8  NORTH   AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

tive  sample  areas  were  selected  for  intensive  study.  The  birds  were 
then  "rope  counted"  *  on  the  sample  tracts.  Finally,  the  total  popu- 
lation of  the  area  was  estimated  from  the  data  obtained  by  counting 
the  sample  plots. 


Tarle  2. — Population  status  of 

^he  Attivater's  prairie  chicken  in  Texas 

(1937) 

Size  of 
tract 

Census  area 

Territory  occupied 
per  bird 

Popula- 
tion of 
■whole 
tract 

County 

Size 

Popula- 
tion (rope 
count) 

Census 
area 

Whole 
tract 

Acres 

Acres 
1,080 
530 

Number 

56 

106 

Acres 
19.2 
5.0 

Acres 

Numhtr 

Total  or  average  (1)  ' 

42,000 

6,554 
5,000 

1,610 

162 

9.9 

4,242 

3  25 

Goliad  ^ 

34 

Total  or  average  (2) - 

11,554 

f 

230 
873 
218 

4 
14 
0 

57.5 
62.3 



1 

Total  or  average  (3) 

65, 535 

1,321 

18 



__  73.  4 

892 

4,000 

4.915 
IS,  022 
49, 152 

4,200 
14,250 

32 
315 

131.2 
45.2 

76, 089 

18,450 

347 

53.1 

1,433 

736 

0 

Total  or  average  (5).. 

12, 288 

736 

0 

550 

f       --- 

542 
364 
219 

1.57 
716 

482 

4 

0 
1 
3 
0 
0 

135.5 

Harris -- 

\- 

219.0 
52.3 

1 

Waller 

Total  or  average  (6) -.- 

103, 878 

2,480 

8 

310.0 

335 

f 

585 
248 
269 
334 

29 
2 
1 
2 

20.1 
124.0 
269.0 
167.0 

1 

Brazoria 

1 

Total  or  average  (7) 

54. 067 

1,436 

34 

42.2 

1,281 

4,000 
700 
400 

24 

1 
0 

166.6 
700.0 

Total  or  average  (8) 

91, 724 

5,100 

25 

204.0 

449 

Grand  total  or  average 

457, 135 

31, 133 

594 

52.4 

8,711 

I  Counties  in  which  prairie  chickens  occur  but  in  which  counts  were  not  made  because  of  scarcity  of  birds 
or  similarity  of  the  areas  to  adjoining  counties. 
'  Numbers  in  parentheses  in  total  lines  refer  to  areas  correspondingly  numbered  in  the  map,  fig.  1,  p.  3. 
'  Estimates  supplied  by  game  wardens. 


*  For  an  account  of  the  method  used  in  rope  counting  see  p.  49. 


ATTWATER'S   PRAIRIE    CHICKEN  9 

The  known  range  of  Attwater's  prairie  chicken  in  Texas,  as  of 
September  1937,  aggregated  only  457,135  acres,  as  compared  with 
approximately  6,000,000  acres  in  former  times.  The  range  has  there- 
fore been  reduced  more  than  93  percent  during  the  past  100  years  or  so. 
The  birds  are  still  to  be  found  in  the  counties  of  Aransas,  Kefugio, 
Goliad,  Victoria,  Calhoim,  Dewitt,  Jefferson,  Waller,  Galveston, 
Chambers,  Liberty,  Lavaca,  Wharton,  Colorado,  Matagorda,  Austin, 
Fort  Bend,  Harris,  Brazoria,  and  possibly  Jackson  and  Orange, 
although  they  have  not  been  reported  by  reliable  observers  in  the 
last  two  for  several  years.  They  have  definitely  been  extirpated 
from  Willacy  and  Montgomery  Counties,  and  their  distribution  has 
become  restricted  throughout  the  State,  especially  in  the  counties 
of  Goliad,  DeWitt,  Lavaca,  Calhoun,  Matagorda,  Galveston,  Fort 
Bend,  Liberty,  Jackson,  and  Orange,  if  they  occur  there  at  all. 
Prairie  chickens  had  not  been  seen  in  Goliad  County  for  at  least 
10  years  prior  to  1937,  at  which  time  four  birds  were  reported  on 
the  W.  J.  O'Conner  ranch. 

No  more  than  half  the  grassland  range  in  any  county  except 
Refugio  is  occupied  by  prairie  chickens.  In  the  counties  of  Mata- 
gorda, Lavaca,  Wharton,  Calhoun,  Liberty,  Jackson,  and  Fort  Bend 
even  less  than  10  percent  of  apparently  satisfactory  pasture  is  inhab- 
ited. Roughly,  the  available  range  for  prairie  chickens  is  only  about 
30  percent  occupied  and,  with  the  exception  of  about  20,000  acres 
in  southeastern  Refugio  County,  all  the  occupied  area  has  a  sparse 
population. 

The  total  number  of  prairie  chickens  in  coastal  Texas  in  the 
summer  of  1937  was  only  about  8,700.  The  estimated  1937  popula- 
tion was  probably  less  than  1  percent  of  the  number  believed  to 
have  occupied  the  coastal  prairie  in  peak  years  before  it  was  devel- 
oped by  white  men.  Approximately  4,200  chickens  (or  almost  50 
percent  of  the  known  population  of  the  State)  inhabit  two  ranches 
in  Refugio  and  Aransas  Counties.  The  estimated  population  of 
4,500  birds  for  the  remainder  of  Texas  is  small  indeed ! 

The  consensus  is  that,  during  the  past  10  years,  the  number  of 
prairie  chickens  has  decreased  in  all  coastal  counties  except  Refugio 
and  Brazoria.  In  Refugio  County  there  has  been  a  rapid  increase 
in  recent  years,  probably  largely  because  of  excellent  protection  on  the 
Salt  Creek  and  Martin  O'Conner  ranches.  Since  1935  the  birds  have 
spread  from  these  onto  the  O'Brien,  Powers,  Welder,  and  Heard 
ranches  near  Greta,  Refugio  County,  and  probably  also  into  Goliad 
County.  Because  of  protection  during  a  5-year  close  season  in 
Brazoria  County  (1932-36),  R.  Z.  Cowart,  State  game  warden  there 
believes  that  in  1937  the  number  of  birds  had  reached  and  possibly 
slightly  exceeded  the  1927  population  level. 


10       NORTH  AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

The  prairie  chicken  population  of  the  counties  of  Orange,  Liberty, 
Fort  Bend,  Matagorda,  Jackson,  Lavaca,  Calhoun,  and  Goliad,  where 
populations  of  less  than  100  birds  per  county  obtain,  may  already  be 
reduced  to  the  point  where  recovery  will  be  extremely  difficult  or 
even  impossible.  So  long  as  any  birds  remain,  however,  every  effort 
should  be  made  to  build  up  their  numbers. 

HABITS 

COURTSHIP  AND  MATING 

Prairie  chickens  do  not  pair  for  breeding,  but  are  promiscuous. 
Males  occupy  selected  courtship  stations  on  booming  grounds  (see 
frontispiece) ,  which  are  visited  by  the  females.  Copulation  may  take 
place  elsewhere,  however,  in  case  of  chance  meetings.  To  attract  the 
females,  the  cocks  put  on  elaborate  exhibitions,  and  their  courtship 
antics  are  unbelievably  weird.  Of  special  interest  is  the  manner 
in  which  the  booming  call  is  rendered. 

This  call  of  the  male  resembles  somewhat  the  sound  whur-ru-rrr^ 
with  strong  accent  on  the  second  syllable.  Although  it  generally 
lasts  about  5  seconds,  the  call  varies  in  length  and  tone.  In  mid- 
season  the  calls  are  characteristically  deep  and  full-throated;  later 
they  become  shorter  and  higher  pitched,  possibly  because  the  males 
are  then  less  vigorous.  The  sound  of  the  booming  carries  for  a 
mile  or  more  on  quiet  days.  It  has  a  ventriloquial  effect  and  often 
seems  farther  away  or  closer  than  it  actually  is.  During  the  court- 
ship season  males  boom  regularly  in  early  morning  (sunrise  until 
about  8  a.  m.)  and  in  late  afternoon  (5:30  p.  m.  until  sunset),  but 
calls  have  been  heard  at  all  hours  of  the  day  and  night.  Booming 
at  night  is  sporadic,  however,  even  during  the  peak  of  the  courtship 
season  in  March,  being  most  common  when  the  moon  is  bright  and 
when  there  is  little  wind. 

The  appearance  of  the  male,  while  booming,  is  striking.  As  a 
preliminary  to  uttering  the  call  he  stretches  his  neck  forward  par- 
allel to  the  ground.  The  erected  pinnae,  or  neck  tufts,  point  for- 
ward; the  spread  tail  is  held  vertically  or  even  inclined  slightly 
over  the  back.  The  wings  are  extended  downward  and  held  firmly 
against  the  body  and  legs,  the  primaries  almost  touching  the  ground. 
The  whole  body  appears  strained  and  rigid.  A  short  run  forward  is 
followed  by  vigorous  stamping  with  the  feet,  which  lasts  only  a  few 
moments,  but  which  under  favorable  conditions  is  distinctly  audible 
for  50  feet  or  more.  Inflation  of  the  air  sacs,  which  are  actually 
but  one  sac  with  two  lateral  portions  (pi.  3)  is  synchronized  with 
the  stamping.  The  first  syllable  of  the  booming  is  given  before 
stamping  ends,  the  male  quickly  jerking  his  head  downward  as  he 
begins  the  call  and  keeping  it  there  until  the  air  sac  is  deflated. 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  3 


Male  Attwater's  prairie  chicken,  showing  vocal  sacs.      (Photo  from  Texas  Game, 
Fish,  and  Oyster  Commission.) 


ATTWATER'S   PRAIRIE    CHICKEN  11 

The  call  of  Attwater's  prairie  chicken  apparently  is  given  in  the 
same  manner  as  was  that  of  the  extinct  heath-hen,  its  near  relative. 
Gross  (Bent  1932:  272)  describes  the  booming  mechanism  of  the 
heath-hen  as  follows : 

The  sacs  do  not  produce  the  notes,  as  was  thought  by  some  of  the  earlier 
ornithologists,  but  have  much  to  do  with  modifying  the  sounds  produced  by 
the  syrinx  (the  vocal  mechanism  at  the  juncture  of  the  bronchial  tubes).  The 
sounds  are  produced  by  the  air  forced  from  the  lungs,  which  vibrate  specialized 
membranes  of  the  syrinx  under  control  of  a  complex  set  of  muscles.  The 
sound  waves  then  issue  through  the  trachea  and  glottis  to  the  pharynx.  In 
the  production  of  such  notes  as  the  ordinary  cackle  the  mandibles  are  opened 
and  the  air  accompanied  by  the  sound  waves  issues  out  of  the  mouth.  In  the 
tooting  [booming]  performance  the  mandibles  are  tightly  closed,  the  throat 
patch  is  elevated,  and  the  tongue  is  forced  against  the  roof  of  the  mouth 
(palate)  by  the  mylohyoides  muscles,  which  close  off  the  exit  through  the 
internal  nares.  The  tongue  is  bent  in  such  a  way  that  it  causes  the  glottis  at 
the  base  of  the  tongue  to  open  directly  in  front  of  the  esophagus.  The  air 
now  coming  from  the  respiratory  system  is  forced  to  fill  the  modified  anterior 
end  of  the  esophagus,  or  gullet,  which  becomes  distended  like  a  balloon.  While 
the  air  sac  is  filling,  the  sound  waves  produced  by  the  syrinx  beat  against 
these  tense  drumlike  membranes,  which  serve  as  resonators  for  the  sounds 
and  give  them  their  great  carrying  power. 

The  booming  call  does  not  complete  the  vocabulary  of  male  prairie 
chickens  at  courtship  time.  The  rendition  of  additional  calls,  all 
distinctly  henlike,  is  described  as  closely  as  possible  on  p.  12.  On 
windy  days  cackling  sounds,  like  Nos.  1,  2,  and  3  in  the  list,  carry 
farther  than  booming.  The  call  note  piooih  (No.  14)  dominates 
when  hens  visit  the  courtship  grounds.  Observers  may  identify 
grounds  where  females  are  present  by  this  piuoik  call. 

Males  do  not  confine  their  courtship  activities  to  vocalizing,  and 
fights  are  common.  Opponents  usually  approach  each  other,  utter- 
ing peculiar  whining  notes,  with  necks  outstretched,  ear  tufts  erected, 
tails  spread,  wings  drooped,  and  air  sacs  deflated.  Then,  as  if  pos- 
sessed of  the  same  thought,  they  suddenly  hop  off  the  ground,  wings 
beating  rapidly,  and  clash  in  midair.  These  bouts  are  usually  dis- 
continued after  three  or  four  flurries,  and  the  victors  seem  satisfied 
after  pursuing  their  opponents  for  short  distances.  Many  feathers 
are  frequently  lost,  but  fights  seldom  if  ever  end  fatally.  Males 
sometimes  engage  fancied  opponents,  as  clumps  of  weeds  or  tufts 
of  tall  grass,  and  at  other  times  they  joust  and  bluff  for  periods  up 
to  30  minutes  or  more  without  striking  a  blow.  With  necks  out- 
stretched, heads  held  a  few  inches  apart,  and  wings  dangling  loosely, 
they  resemble  domestic  roosters  fighting.  At  intervals  males  flutter 
into  the  air  to  heights  of  3  to  5  feet,  alighting  nearly  on  the  spot 
whence  they  arose.     Their  surplus  energy  apparently  must  be  expended 

303807°— 41 2 


12       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

in  one  way  or  another,  although  activity  sometimes  lags  for  brief 
periods. 

CAIX    OF    MALE    PRAIEEE    CHICEIONS    ON    COXJBTSHIP    GROUNDS 

1.  Ca-ca'-carca-ca-ca-ca-ca-caa-caa—.  All  except  last  two  notes  given  rapidly, 

2.  Ca-ca'-caa,   ca-ca'-caa Rapid. 

3.  Ca-ca-ca-ca'-ca Rapid,  accent  on  second  to  last  syllable. 

4.  Ca-ca-ca-ca-keece All  except  last  syllable  given  rapidly. 

5.  Kmeee,   ca-ca-ca-oa-ca-ca First  syllable  dravpn  out,  remainder  given 

rapidly. 

6.  Kwerr-kwerr-pwah First  two  syllables  drawn  out. 

7.  Kwier-kwier-ku-ier-kicier All  syllables  drawn  out. 

8.  Pwark  or  pwarrk Medium    rapid.     Often    preceeds    cackling 

or  booming,  carries  as  far  as  or  farther 
than  booming  notes  under  certain 
weather  conditions. 

9.  Caaa-caaa-caaa-caaaa Slow  and  drawn  out.     Sounds  almost  ex- 

actly like  protests  of  a  domestic  setting 
hen  that  is  disturbed. 

10.  Pwiek,  pwark Medium  rapid. 

11.  Pwiek,   pwiek,  pwiek All    notes    drawn   out   with    emphasis    on 

the  iek. 

12.  Pwiek,   ca-ca-ca-ca-ca-ca<i Pause  after  first  note,  cackle  given  rapidly. 

13.  Pwk-pwk-pwk-pwk-pwk-pwk Har.sh   notes   executed   rapidly,    but   in    a 

subdued  tone. 

14.  Pwoik,  pwoik,  pwoik,  pwoik Executed   rapidly    and    with   much   vigor. 

These  notes  predominate  all  other  calls 
when  a  female  approaches  a  courtship 
ground. 

15.  Kliee,  kliee,   kliee;  ca-ca-ca-ca—  Kliee's  drawn  out ;  ca's  given  rapidly.    This 

is  a  prominent  call  in  early  spring. 

16.  Kwoo,  kiooo;  kwah,  kwah Rapid.     Another   prominent    early    season 

call. 

The  performers  do  considerable  feeding  when  they  first  arrive  on 
the  courtship  ground,  and  certain  of  them  feed  sporadically  throughout 
their  stay.  At  other  times  individuals,  sometimes  an  entire  group,  sit 
or  stand  in  their  places  and  look  about.  Rest  periods  terminate 
abruptly,  however,  when  a  male  recognizes  a  real  or  fancied  challenge, 
or  when  a  hen  appears. 

While  the  male  is  bold  and  noisy  during  the  mating  season,  the  female 
is  demure  and  shy.  Hens  visit  the  courtship  grounds  irregularly  except 
early  in  March.  Even  in  well-populated  territory  a  week  sometimes 
elapses  before  the  persistent  male  performers  are  rewarded  by  female 
company.  When  on  or  near  a  drumming  ground,  hens  usually  appear 
little  interested  in  the  spirited  antics  of  the  obviously  excited  males. 
Sometimes,  however,  they  walk  among  the  contestants  and  mate  with 
one  or  several  of  them.  Hens  usually  remain  at  the  courtship  areas 
briefly;  usually  they  stay  only  a  few  minutes  before  leaving  to  feed 
elsewhere  or  fly  to  the  vicinity  of  their  nests. 


ATTWATER'S   PRAIRIE    CHICKEN  13 

In  Colorado  County  signs  of  the  approaching  breeding  season  were 
noted  early  in  January  (1937)  and  late  in  December  (1938)  when  cer- 
tain males,  probably  the  most  vigorous,  pecked  at  and  otherwise  bullied 
their  fellows  as  the  flocks  left  the  roost  or  fed  early  each  morning.  A 
few  weeks  later,  early  in  February  (1937),  and  late  in  January  (1938), 
males  assembled  early  in  the  morning  on  short-grass  areas  that  later 
served  as  courtship  grounds,  and  fought  and  maneuvered  for  choice 
positions.  For  a  week  or  more,  calls  consisted  largely  of  miscellaneous 
squawks  and  cackles,  and  fights,  though  frequent,  were  of  short  dura- 
tion. Males  occasionally  attempted  to  drum  or  boom,  but  their  notes 
lacked  midseason  depth  and  vigor.  Females,  still  in  winter  flocks, 
seemed  indifferent  to  the  proceedings.  It  was  not  until  February  12,  in 
1937,  and  January  26,  in  1938,  that  booming  was  commonly  heard,  and 
each  year,  after  2  to  3  weeks,  flocks  of  females  generally  broke  up  and 
the  courtship  season  was  well  under  way.  During  both  1937  and  1938 
courtship  activity  was  at  its  peak  in  March,  continuing  through  April 
and  ending  on  May  20,  in  1937,  and  on  May  21,  in  1938,  when  the  last 
booming  calls  were  heard. 

Key  areas  during  the  courtship  season  are  the  booming  grounds  where 
males  assemble  each  morning  from  daybreak  until  about  8  a.  m.  and 
each  afternoon  from  5:30  p.  m.  until  dark  and  give  their  courtship 
display. 

The  preferred  booming  ground  is  a  short-grass  flat,  an  acre  or  so  in 
extent,  surrounded  by  an  area  of  medium  to  heavy  grassy  cover  suitable 
for  nesting.  Of  several  hundred  sites  observed  during  3  years  (1936- 
38)  only  one  was  on  ground  elevated  enough  to  be  termed  a  small  knoll. 
The  others  were  even  with  or  slightly  below  the  adjacent  land  surface. 
Stoddard  (Bent  1932:  245),  discussing  the  greater  prairie  chicken  in 
Wisconsin,  says  that  "the  'cooing'  ground  [courtship  ground]  at  the 
sandy  west  end  of  Sauk  Prairie  has  been  used  each  spring  for  over  30 
years,  the  birds  always  using  the  same  knoll  whether  in  rye,  stubble, 
or  grown  to  grass."  Courtship  grounds  of  Attwater's  prairie  chicken 
do  not  show  the  same  degree  of  permanence.  Cultivation  seemingly  re- 
sults in  immediate  eviction,  whether  the  crop  is  rice,  corn,  cotton,  or 
something  else.  Likewise,  the  birds  do  not  use  fallow  fields  except  where 
cultivated  land  is  the  only  other  environmental  type  available,  or  where 
the  fallow  land  has  aged  to  the  extent  that  its  surface  and  vegetation 
are  nearly  identical  with  that  of  nearby  grassland.  Even  those  court- 
ship grounds  that  are  in  pastures  may  or  may  not  be  occupied  each  year 
for  a  series  of  years.  Of  10  such  grounds,  on  which  records  were  ob- 
tained from  1936  through  1938,  only  5,  or  50  percent,  were  occupied  each 
year.  Their  populations  were  fairly  stable  (see  table  3,  p.  14).  Of 
the  others,  2  were  occupied  in  1936  and  1937 ;  2  were  unused  except  in 
1936 ;  and  1  was  occupied  in  1936,  in  part  of  1937,  and  throughout  the 
entire  season  in  1938.    There  was  little  variation  in  the  prairie  chicken 


14       NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

population  of  the  pastures  in  which  these  courtship  grounds  were  situ- 
ated, but  in  every  instance  the  vegetation  on  or  near  the  study  areas 
varied  in  density  through  grazing  or  burning.  Cover  changes  on  and 
near  courtship  areas  influenced  their  attractiveness  to  the  birds,  possibly 
to  the  point  of  determining  whether  they  would  be  occupied  and  by 
how  many  individuals. 

Table  3. — Occurrences  in  S  years  of  male  prairie  chickens  on  5  courtship  founds 

in  Color-ado  County 


Observations 

Birds  observed 

Name  of  pasture 

Extremes 

Averages 

1936 

1937 

1938 

1936 

1937 

1938 

1936 

1937 

1938 

Thomas        .  -  

2 
2 
2 
2 
2 

11 
8 
14 
13 
20 

6 
6 
6 
11 
12 

7-  9 
9-11 

6-  9 
3-10 

4-11 
5-  8 
3-  8 
5-13 
6-14 

8.0 
10.0 
5.5 
7.0 
7.0 

7.0 
6.0 
8.0 
9.0 
6.0 

8.0 

Do          

7.0 

Do       

5-6         3-9 

7.0 

6-  8 

5-11 

10.0 

7-  7 

0-  8 

10.0 

Total  or  average 

10 

66 

42 

7.5 

7.2 

8.4 

NESTING 


While  the  males  are  still  engaged  in  their  courtship  performances, 
the  females  quietly  select  and  improve  the  nest  sites  and  attend  to 
laying,  incubating,  and  hatching  the  eggs  and  rearing  the  young. 
Nests  (pi.  4)  are  made  on  the  ground.  Of  19  examined  in  1937 
and  1938,  17  were  in  long-grass  pastures,  1  in  a  hay  meadow,  and 
1  in  a  fallow  field.  All  were  in  dead  grass  of  the  previous  year's 
growth.  Fifteen  (about  76  percent)  were  on  or  near  well-drained 
mounds  or  ridges,  and  4  were  in  poorly  drained  situations.  In  a 
choice  of  nest  sites,  cover  appeared  of  more  importance  than  topog- 
raphy and  the  structure  of  the  soil.  Twelve  (63  percent)  of  the 
study  nests  were  situated  within  10  yards  of  well-marked  trails, 
possibly  because  prairie  chickens  dislike  walking  through  heavy 
matted  vegetation  when  approaching  or  leaving  their  nests.  Cattle 
make  many  trails,  thereby  improving  nesting  areas. 

Study  nests  were  found  always  within  a  radius  of  half  a  mile 
to  a  mile  from  occupied  booming  grounds.  Sometimes  the  sites  were 
rather  distant  from  acceptable  feeding  territory,  although  flights  of 
up  to  a  mile  seemed  to  inconvenience  the  birds  very  little. 

Nests  were  merely  shallow  depressions,  about  7  inches  in  diameter, 
lined  with  bits  of  dead  grass,  twigs,  and  a  few  feathers,  presumably 
from  the  females.  All  were  more  or  less  roofed  over  because  of  the 
lapping  or  bending  over  of  surrounding  vegetation.  Entrances  faced 
in  various  directions  with  no  preference  shown.  There  was  consid- 
erable variation  in  degree  of  concealment  (pi.  5),  at  least  according 
to  human  standards;  5  nests  being  excellentl}^,  10  well,  and  4  poorly, 
concealed.     Kapid  new  plant  growth  in  April  and  May  aided  ma- 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


,^   o 


o  O 


■o3   a 
bi    o 


^    o 
o3  ;r 


5 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  5 


^r 


:r  ^-/i*^. 


C3        ii 

;^    o    S 
5  ^  00^ 


^O 


ATTWATER'S   PRAIRIE    CHICKEN  15 

terially  in  hiding  nests ;  consequently,  some  nests  that  were  relatively 
exposed  when  found  were  well  hidden  later.  Wild  indigo  {Baptisia 
sp.),  vetch  {Vicia  litdoviciana) ,  phlox  (  Phlox  drummondii) ^  peren- 
nial ragweed  {Ambrosia  psilostax^hya) ^  dogfennel  {Eupatorium  sp.), 
and  panic  grass  {Panicum  sp.)  were  green  plants  that  aided  con- 
cealment materially  by  mid-May.  In  Colorado  County,  favorite 
nesting  materials  were  dry  bluestem  grass  {Andropogon  scoparius), 
and  paspalum   {Paspalum  dilatatuTn). 

The  earliest  date  for  a  nest  containing  eggs  was  reported  by  Wad- 
dell  near  Egypt,  Wharton  County,  February  25,  1925;  the  latest 
record  is  that  of  a  nest  in  Colorado  County  in  which  the  clutch 
was  completed  May  29,  1938.  In  both  1937  and  1938,  however,  the 
peak  of  the  laying  season  in  Colorado  County  was  late  March  and 
early  April.  Hens  always  laid  in  the  morning,  usually  from  7:30 
to  9,  flying  to  the  vicinity  of  their  nests  when  ready.  After  cautiously 
looking  about  or  feeding  a  bit  longer,  hens  walked  to  the  nests  and 
remained  there  for  from  about  20  minutes  to  an  hour.  The  laying 
completed,  they  regularly  walked  about  20  feet  from  the  nest,  scanned 
the  landscape,  and  flew  away.  Since  incomplete  clutches  were  un- 
guarded except  during  about  an  hour  each  day,  they  were  especially 
vulnerable  to  natural  enemies. 

Hens  under  observation  normally  laid  an  Qgg  a  day  until  the 
clutch  of  8  to  15  was  complete,  but  sometimes  they  failed  to  lay  for 
periods  of  1  to  3  days.  Clutches  usually  contained  12  eggs,  and  lay- 
ing was  generally  completed  in  about  2  weeks.  The  period  of  egg 
laying  was  sometimes  extended,  however,  when  nests  were  destroyed. 
Three  hens,  each  the  only  resident  on  a  small  unburned  plot,  re- 
nested  during  1937,  one  of  them  three  times. 

New  nests,  however,  were  placed  5  to  20  yards  from  old  ones,  and 
were  less  effectively  concealed.  Destructive  agents  had  even  greater 
opportunities  to  take  the  later  nests,  as  they  did  in  four  out  of  five 
cases.  Since  booming  ended  by  mid-May,  the  period  for  mating 
was  short.  Late  broods  were  invariably  smaller  than  early  ones, 
probably  because  late  clutches  were  small,  their  hatchability  low,  or 
their  mortality  heavy.  A  successful  season  depends  largely  on  the 
fate  of  early  nests,  so  that  a  primary  objective  of  management  should 
be  to  safeguard  these  attempts. 

Twenty-nine  eggs  of  Attwater's  prairie  chicken  measured  by  Bent 
(1932:  264)  averaged  42.3  by  31.5  millimeters  in  size,  showing  ex- 
tremes of  44.9  by  32,  42.4  by  33.5,  38.8  by  28.9,  and  39.8  by  28.6 
millimeters.  Newly  laid  eggs  were  dull  cream  or  bluish  buff  in 
color,  some  of  them  minutely  specked  with  red.  During  incubation 
the  color  of  the  eggs  became  dull  and  the  shells  shiny.  Incubation 
began  at  from  1  day  before  until  4  days  after  the  last  egg  was  laid. 


16      NORTH  AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

Except  for  two  feeding  and  resting  periods  daily,  extending  from 
about  7  to  8  a.  m.  and  from  5 :30  to  6 :30  p.  m.,  hens  incubated  con- 
stantly. When  incubation  was  advanced,  morning  feeding  was  fre- 
quently dispensed  with.  Two  clutches  pipped  approximately  23  and 
24  days  after  setting  began,  in  each  instance  requiring  about  48  hours 
longer  to  hatch.  Of  71  eggs  in  7  nests,  only  3  (about  4  percent) 
were  infertile,  66  hatching  successfully.  Seemingly,  fertility  and 
hatchability  are  high  under  favorable  conditions. 

The  hatching  period  was  evidently  a  time  of  danger.  Chicks 
peeped  incessantly  and  scrambled  in  and  out  of  the  nest.  Nests 
emitted  strong  odors,  apparent  even  to  man.  Females  at  hatching 
time  appeared  nervous  and  shifted  their  positions  frequently.  Unless 
disturbed,  however,  they  did  not  leave  until  the  last  egg  had  hatched, 
after  which  they  deserted  the  nests.  In  1937  a  nest  in  which  all 
young  were  hatched  by  11 :  50  a.  m.  on  May  15  was  vacated  by  3  p.  m. 
that  day,  and  a  brood  that  was  hatching  at  8 :  30  a.  m.  on  June  2  was 
gone  24  hours  later.  One  hen  left  before  2  pipped  eggs  were  hatched 
and  before  the  natal  down  on  some  of  the  young  was  dry,  probably 
because  fire  ants  [Solenopsis)  had  entered  the  nest. 

GROWTH  AND  DEVELOPMENT  OF  YOUNG 

When  leading  chicks  from  the  nest,  old  bird^  traveled  through 
the  lightest  cover  or  followed  trails,  probably  because  heavy  matted 
vegetation  impeded  progress  and  increased  the  chance  of  chicks  get- 
ting lost.  Cow  trails  were  favorite  travel  ways.  Chicks  ranged  in 
front,  behind,  and  on  both  sides  of  the  hen  over  an  area  1  to  6  yards 
in  radius.  Interruptions  for  sporadic  feeding  and  for  frequent 
brooding,  which  was  probably  more  necessary  for  assembling  than 
for  warming  the  young,  made  progress  slow.  Hens  with  chicks  less 
than  10  days  old  (pi.  6)  seemed  mainly  concerned  with  watchfulness 
and  brooding.  Occasionally  they  caught  available  insects  or  nipped 
off  a  few  green  leaves  or  bud^,  but  they  did  little  continuous  feeding. 
When  danger  threatened,  they  gave  a  warning  call,  best  described 
as  a  low  kwerr^  hwerr^  krcerr,  and  slowly  gkulked  through  the  grass 
with  head  lowered  and  wings  dangling  loosely,  almost  touching  the 
sod.  Young  birds  "froze"  with  their  bodies  closely  pressed  to  the 
ground.  Decoy  efforts  of  adult  females  were  never  so  energetic  as 
those  of  bobwhites  under  similar  circumstances.  When  hens  were 
flushed,  the  chicks  in  hiding  (pi.  6)  became  impatient  after  3  to  5 
minutes,  and  peeped  and  ran  about  in  spite  of  the  fact  that  the  object 
of  suspicion  remained.  After  the  immature  birds  of  2  to  3  weeks 
of  age  could  fly  fairly  well,  females  accompanying  them  did  not 
decoy,  but  always  flushed  freely,  the  young  doing  likewise. 

Chicks  that  were  less  than  a  week  old  were  brooded  quite  often, 
probably  in  all  for  about  50  percent  of  the  daylight  period.    Ten  birds 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  6 


Above,  Chicks  about  10  days  old;  Colorado  County,  Tex.,  approximately  6  miles 
north  of  Eagle  Lake,  May  3,  1938.  Beloiv,  Chicks  hiding;  Colorado  County, 
Tex.,  approximately  6)4  miles  north  of  Eagle  Lake,  May  3,  1938.  (Photos 
from  Texas  Game,  Fish,  and  Oyster  Commission;  E.  P.  Haddon.) 


ATTWATER'S   PRAIRIE    CHICKEN  17 

about  2  days  old  were  brooded  42  minutes  out  of  the  II/2  hours  during 
which  they  were  watched  on  May  4,  1937.  Their  position  during 
brooding  was  interesting.  Hens  squatted  low  with  legs  at  an  angle 
of  a.bout  30  degrees  with  the  ground.  Wings  were  drooped  and 
feathers  of  the  underparts  were  ruffled.  Some  chicks  scrambled  up 
and  under  the  wings.  When  the  brooding  hens  were  frightened  and 
suddenly  stood  erect,  usually  only  two  or  three  chicks  were  visible; 
the  others,  however,  tumbled  from  beneath  her  wings  a  few  moments 
later.  As  the  chicks  grew  older,  the  time  spent  brooding  diminished; 
those  2  weeks  old  apparently  were  brooded  little  except  early  in  the 
morning,  during  inclement  weather,  and  at  night. 

JsTewly  hatched  chicks  are  about  the  gize  of  day-old  bantams,  and 
their  coloration  is  nearly  identical  with  that  of  young  bronze  turkeys. 
The  basic,  buffy  yellow  is  streaked  with  gray  on  head  and  upper- 
parts.  Growth  and  development  are  rapid.  Wing  feathers  appear 
almost  at  once;  week-old  chicks  have  primaries  approximately  five- 
eighths  of  an  inch  long.  Chicks  fly  when  2  weeks  old.  Except  for 
differences  in  the  length  of  the  tail  and  legs,  they  are  about  the  size 
of  English  sparroWiS.  When  3  weeks  of  age,  youngsters  are  almost 
as  large  as  starlings  and  can  make  sustained  flights  of  40  yards  or 
more.  At  4  or  5  weeks,  young  birds  approximate  the  size  of  mature 
bobwhites,  and  often  fly  a  hundred  j^ards  before  alighting.  When 
6  or  7  weeks  old,  the  young  are  about  half  grown  and  at  8  or  9  weeks 
they  are  three-fourths  the  size  of  adultjs.  Youngsters  10  to  12  weeks 
old  can  scarcely  be  differentiated  from  the  old  birds  in  the  field. 
Weight  evidently  does  not  increase  as  rapidly  as  size,  however,  for 
two  birds  approximately  3  months  old  were  more  than  a  pound  lighter 
than  mature  individuals. 

As  young  prairie  chickens  grow  in  size,  all  cannot,  of  course,  main- 
tain a  brooding  position  under  the  sheltering  body  of  the  mother. 
Usually  by  the  time  they  are  about  3  weeks  old  some  are  forced  out- 
side; there  they  sleep  with  bodies  pressed  closely  to  that  of  the  hen. 
When  4  to  5  weeks  of  age,  two  or  three  chicks  sometimes  crowd  under 
their  mother,  but  the  remainder  roost  from  a  few  inches  to  about  2  feet 
away.  At  6  to  7  weeks,  young  birds  adopt  the  roosting  formation  of 
adults.  Flocks  of  Attwater's  prairie  chickens  sleep  about  a  foot  or  so 
apart,  the  individuals  facing  in  different  directions.  Roosting  spots 
vary  in  size  from  1  to  3  square  yards  or  more,  depending  on  the  number 
of  birds  in  the  group.  The  number  of  scats  left  at  a  roosting  site 
is  not  an  absolutely  accurate  index  to  the  number  of  birds  in  a  flock, 
because  slight  shifting  of  individuals  during  the  night  brings  about  the 
deposition  of  more  than  one  pile  by  a  bird. 

Chicks  about  2  weeks  old  take  vigorous  dust  baths,  a  habit  that  is 
indulged  in  regularly  throughout  life  when  dry,  powdery  material  is 


18       NORTH   AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

available.  Prairie  chickens  generally  dust  during  the  midday  rest 
period  that  extends  from  about  10  a.  m.  to  4  p.  m.  Old  pocket  gopher 
mounds  and  cattle  wallows  are  favorite  places.  Some  birds  use  the 
same  dust  bath  more  than  once. 

BROOD  SIZE 

The  size  of  the  brood  generally  decreases  with  the  age  of  the  young. 
Of  48  broods  on  which  accurate  counts  were  kept  (table  4,  below)  6 
from  1  to  3  days  old  contained  64  young,  averaging  10.6  birds  each. 
Three  broods  estimated  to  be  5  to  10  days  old  contained  only  14  chicks 
averaging  4.6  each.  Four  broods  15  to  27  days  old  had  22  young,  or 
an  average  of  5.5.  Fifteen  families  over  4  and  under  6  weeks  of  age 
aggregated  80  young  and  averaged  5.3.  Twenty  groups  over  6  weeks 
totaled  80  young  and  averaged  4  each.  The  average  size  (5.3  young) 
of  15  families,  estimated  to  be  over  4  but  under  6  weeks  of  age,  was 
exactly  half  the  average  size  (10.6)  of  6  new  broods.  The  average 
size  (5.3)  of  15  families  over  4  but  under  6  weeks  old  was  but  slightly 
larger  than  the  average  size  (4.0)  of  20  families  older  than  6  weeks. 
Therefore,  it  appears  that  juvenile  mortality  is  heaviest  during  the 
first  4  weeks  and  comparatively  light  thereafter. 


Table  4. — Size  of  'broods  and  number  of  chicks  counted  during  May, 

July 

June,  and 

County 

Date 

Family 

groups 

observed 

Chicks 

per 
group 

Chicks  per 
average 
group 

May    4 
May  15 
May  18 
May  23 
May  28 
May  29 
May  31 

1 
1 
1 
3 
3 
1 
2 

10 

12 

12 

2,4,2 

7, 9, 11 

8 

4,8 

10.00 

Do                     —       

12.00 

Do                   

12.00 

Do               

2.66 

Do                

9.00 

Do         

8.00 

Do                      -      -  -      

6.00 

Total  or  average  for  May                 

12 

89 

7.41 

June    2 
June    3 
June     8 
June  10 
June  24 

4 
1 
2 
2 
3 

6,  9,  4,  2 

10 

3,3 

4,8 

5,4,3 

6.33 

Do                     

10.00 

Do               

3.00 

Do               

6.00 

4.00 

Total  or  aVTS^ge  foJ"  .Tutia 

12 

61 

5.08 

July     1 
July     8 
July    14 
July    17 
July    19 
July    26 

3 
2 
1 

4 
6 
2 

5,5,6 
3,3 

7 

10,  8, 1,  3 

10,  2,  2,  4,  5,  2 

10,5 

5.33 

3.00 

7.00 

6.00 

Do 

4.16 

Colorado               -  -- 

8.00 

18 

92 

5.  U 

Aug.   12 
Sept.    2 
Sept.    3 
Sept.    4 

1 
3 

1 
1 

3 

5,3,3 

3 

4 

3.00 

3.66 

Do         

3.00 

Do                         

4.00 

5 

18 

3.60 

48 

263 

5.48 

ATTWATER'S   PRAIRIE    CHICKEN  19 

JUVENILE  MORTALITY 

Although  much  remains  to  be  learned  about  juvenile  mortality, 
its  causes  were  fairly  well  established  in  some  instances.  Chicks  are 
sometimes  trapped  and  drowned  in  rice  fields  at  the  time  of  flooding 
(usually  about  May  10).  In  1925,  near  Egypt,  Wharton  County, 
Waddell  and  others  picked  up  hatfuls  of  chicks  and  carried  them 
beyond  the  levees.  In  1937  a  farmer  near  Eagle  Lake  similarly  res- 
cued a  brood.  The  number  of  chicks  annually  saved  from  this 
hazard,  however,  is  probably  insignificant  in  contrast  to  those  lost. 
Prairie  fires  kill  young  and,  as  stated  on  page  42,  burning  is  still 
common  in  certain  areas  at  nesting  and  brooding  time.  Unfavorable 
weather,  especially  rains  (pp.  32  to  35)  and  natural  enemies  (p.  39), 
account  for  the  death  of  some  young  birds,  but  no  small  percentage 
of  these  may  be  chicks  that  are  lost. 

Chicks  stray  from  the  brood  more  often  than  one  might  suspect. 
During  April,  May,  and  June,  1937,  no  fewer  than  13  strays  were 
seen,  all  under  4  weeks  old.  Usually  they  occurred  as  singles,  but 
sometimes  in  pairs  and  trios.  How  the  youngsters  became  lost,  of 
course,  was  usually  unknown,  but  several  reasons  were  apparent. 
The  characteristic  loose  feeding  formation  of  broods  possibly  con- 
tributed to  straying;  also,  broods  usually  scattered  widely  and  flew 
far  when  disturbed;  and,  possibly  most  significant  of  all,  adults  did 
not  appear  to  have  a  highly  developed  rallying  call  that  doubtless 
would  be  of  assistance  in  reassembling  youngsters. 

Lost  chicks  evidently  join  other  gi'oups  occasionally,  as  hens  ac- 
companied by  young  of  varied  sizes  were  several  times  noted  in  1937. 
Once  two  chicks,  about  2  and  3  weeks  old,  respectively,  were  seen 
with  two  molting  males.  Higher  population  levels  might  increase 
the  frequency  of  adoptions. 

FAMILY  DISINTEGRATION 

Many  young  Attwater's  prairie  chickens  6  to  8  weeks  old  leave  the 
family  groups  and  take  up  life  on  their  own,  but,  as  is  true  with 
domestic  chickens,  all  young  do  not  leave  the  hen  at  the  same  time; 
disintegration  of  the  family  group  is  gradual.  Some  young  remain 
with  the  hen  well  into  the  fall.  Unattached  young,  6  weeks  of  age 
or  older,  as  distinguished  from  lost  chicks  less  than  a  month  old, 
became  noticeable  late  in  June  and  they  were  frequently  seen  after 
July.  Family  disintegration  after  6  weeks  or  thereabouts  is  normal. 
Young  prairie  chickens  at  that  age  seem  as  capable  of  foraging  and 
resisting  adverse  weather  as  are  the  adults. 


20       NORTH   AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

ANNUAL  INCREASE 

The  actual  survival  of  young  prairie  chickens  (table  5,  below)  prob- 
ably is  always  well  below  the  potential  yield  (12  or  so  young  from 
each  hen)  even  when  favorable  weather  conditions  obtain  during 
the  critical  breeding  season. 


Table  5 

. — Young  and  adult  birds  observed 

in  census  after  June  SO,  1931 

Date 

Area 

Adults 

Young 

County 

Males 

Females 

Sex  un- 
known 

Total 

Families 

Strays 

Total 

Brazoria 

Victoria 

July     1 
July  14 
July  17 
July   19 
July   26 
July   27 
Aug.  12 
Sept.    1 

Acres 
585 
921 

1,080 
530 

1,450 
851 

1,282 

2,000 

Number 
2 
1 
1 
3 
0 
2 
1 
1 

Number 
4 
1 
4 
8 
2 
0 
1 
5 

Number 
2 
6 
23 
53 
4 
2 
2 
8 

Number 
8 
8 
28 
64 
6 
4 
4 
14 

Number 

5.5,6 

7 

10, 8, 1, 3 

10, 2,  2,  4,  5, 1 

11,5 

3 

3 

5,3,3 

Number 

1,1,1,1,1 

1,2 

2,1,1,1,1 

1, 1, 2, 1, 1, 1 

2.3 

1 

1 

1, 2, 1. 3 

Number 
21 
10 

Refugio 

28 

Do 

32 

Colorado. 

Brazoria 

Harris  

21 

4 
4 

Colorado 

18 

Total 

8,699 

11 

25 

100 

136 

103 

35 

138 

In  a  rope  count  on  or  after  July  1,  1937,  138  young  as  compared 
with  136  adults  (about  1:1)  were  enumerated  on  an  area  of  more 
than  8,699  acres.  At  this  time  most  of  the  counted  birds  were  4 
weeks  old  or  more  and  were  beyond  the  age  when  mortality  is  thought 
to  be  most  severe.  The  increase  on  the  counted  areas,  then,  was  only 
about  100  percent  in  spite  of  the  fact  that  food,  cover,  and  weather 
conditions  were  favorable.  A  100  percent  increase  of  prairie 
chickens  in  any  one  year  is  very  good,  and  the  arguments  for  long 
open  seasons  and  large  bag  limits,  based  on  the  potential  annual 
increase  (12  chicks  for  each  hen,  or  about  600  percent  a  year),  evi- 
dently are  fallacious. 

FLOCKING 

Late  in  summer  and  early  in  fall,  the  prairie  chickens  displayed  no 
marked  tendency  to  combine  into  stable  groups.  In  August  and 
September  of  1936  and  1937  well  over  half  the  birds  observed  in 
Colorado  County  were  recorded  as  singles,  pairs,  and  trios,  although 
small  groups  of  4  to  6  were  not  uncommon.  Occasional  larger  flocks 
were  recorded,  but  these  appeared  to  be  temporary.  In  Colorado 
County,  at  about  noon  on  September  1,  1937,  a  flock  of  15  to  25  birds 
was  noticed  in  a  cotton  field.  On  the  following  3  days  at  the  same 
hour  11,  15,  and  9  birds,  respectively,  were  present  in  that  field; 
but  they  had  come  in  between  9 :  30  and  11 :  30  as  singles,  pairs,  and 
in  small  groups  not  exceeding  5  birds  each.  Between  4  p.  m.  and 
dark  they  left  the  field  as  they  had  come.  Again  in  Colorado 
County,  at  6  p.  m.  on  September  3,  1937,  another  group  of  16  birds 
found  in  a  pasture  came  together  as  follows ;  At  5 :  40  p.  m.  a  group 


AtTWATER'S   PRAIRIE    CHICKEN  21 

of  8  flushed  approximately  1  mile  from  the  spot  where  the  large 
flock  was  later  noted,  and  as  they  flew  over  the  prairie,  a  pair,  a 
single,  a  trio,  and  another  pair  joined  the  original  group.  All  set- 
tled and  fed  together  for  a  time,  but  the  bevy  disintegrated  by  dusk. 
Like  instances  suggest  that  early  fall  flocks  of  a  dozen  or  so  birds 
are  unstable  groups  brought  together  largely  by  chance. 

In  fall,  after  the  weather  turned  cool,  groups  of  prairie  chickens 
became  the  rule  rather  than  the  exception.  Early  November  bevies 
generally  contained  4  to  12  birds  each,  but  large  flocks  became  in- 
creasingly common  from  about  December  1  to  the  onset  of  the  breed- 
ing season.  Late  in  winter  (January)  Guy  Ferguson,  State  game 
warden,  Sinton,  Tex.,  observed  flocks  in  Refugio  and  Aransas  Coun- 
ties that  contained  more  than  a  hundred  birds.  Wardens  Waddell 
in  Colorado,  Austin,  and  Wharton  Counties,  and  McClosky  in  Vic- 
toria County,  reported  winter  aggregations  of  about  the  same  size. 
In  1936,  J.  O.  Linney,  foreman,  Salt  Creek  (Hallahan)  ranch,  Re- 
fugio and  Aransas  Counties,  noticed  late  winter  concentrations  esti- 
mated to  contain  250  to  300  individuals.  The  writer  has  not  observed 
such  large  winter  flocks,  possibly  because  he  has  not  made  observa- 
tions in  areas  where  the  birds  were  suflficiently  numerous.  January 
assemblages  of  25  to  35  birds  were  not  uncommon,  however,  in  Colo- 
rado County.  Despite  the  fact  that  large  flocks  became  more  fre- 
quent from  November  until  the  breeding  season,  small  groups  of  8 
or  fewer  birds  or  singles  were  always  to  be  found.  All  packs  ob- 
served in  Colorado  County  late  in  November,  December  and  January 
contained  birds  of  only  one  sex.  Late  in  January,  residents  of  the 
coastal  country  eagerly  listen  for  the  first  booming  calls,  which, 
besides  promoting  rapid  disintegration  of  winter  flocks,  signal  the 
departure  of  winter  and  the  coming  of  spring. 

seasonal  movements 
Spring 

Comprehensive  data  on  prairie  chicken  movements  are  lacking,  but 
the  records  obtained  in  1937  are  of  interest.  Two  broods  that  were 
observed  two  or  more  times  daily  from  the  time  they  were  hatched 
until  they  were  7  and  12  days  old,  respectively,  were,  at  last  observa- 
tion, less  than  half  a  mile  from  the  nest  sites.  Another  brood,  esti- 
mated to  be  8  days  old  when  first  discovered  on  June  2,  was  within  150 
yards  of  the  same  spot  at  various  hours  during  the  next  6  days.  A 
fourth  brood,  about  3  days  old  on  April  29,  remained  within  400  yards 
of  a  certain  windmill  from  April  29  through  May  31.  A  640-acre 
pasture  that  contained  four  broods,  all  under  2  weeks  of  age  when 
rope  counted  on  June  2,  likewise  harbored  four  broods  10  days  later. 


22      NORTH  AMERICAN  FAUNA    57,   FISH  AND  WILDLIFE    SERVICE 

If  this  is  indicative,  the  prairie  chickens  under  observation  spent 
their  first  several  weeks  of  life  in  close  proximity  to  the  places  where 
hatched.  The  daily  cruising  radius  of  a  brood  apparently  was  small, 
seemingly  less  than  300  yards  in  the  case  of  birds  under  4  weeks  old 
in  a  favorable  environment.  Some  30  broods  observed  between  May 
1  and  June  1  were  found  in  light  cover  on  or  near  hardpan  flats  and 
recent  burns,  indicating  a  distinct  preference  for  those  types  of  habitat. 

Summer 

An  extensive  movement  involving  both  young  and  adult  prairie 
chickens  in  Colorado  County  began  about  June  1,  1937,  when  many 
of  the  young  were  3  to  5  weeks  old,  and  lasted  until  about  June 
30.  The  sudden  scarcity  of  the  birds  in  places  where  they  had  been 
common  only  a  few  days  before  was  striking.  A  1,000-acre  pasture 
that  contained  37  individuals  (16  old  and  21  young)  on  June  2,  held 
only  16  in  all  on  June  10.  As  the  prairie  chickens  decreased  in  some 
pastures,  they  increased  in  others.  A  460-acre  pasture  that  was  un- 
occupied on  May  1  contained  14  birds  on  June  8  and  23  on  July  26. 
This  movement  from  the  spring  range  was  by  stages.  One  brood 
that  was  watched  closely  made  trips  of  approximately  1  mile,  three- 
fourths  mile,  and  1^  miles  in  6  days  from  June  2  through  June  8. 
After  the  first  major  movement,  this  family  remained  for  3  days  in  an 
area  less  than  500  yards  in  diameter ;  their  droppings  in  piles  formed  a 
triangle  with  sides  of  5,  15,  and  17  yards,  respectively.  The  move- 
ment of  a  combined  brood  of  3  hens  and  16  to  25  young  are  recorded 
in  figure  2,  p.  23. 
Leopold  (1933:  291)  reports  that- 
All  observers  unanimously  and  independently  report  a  strong  tendency  for  the 
grown  young  of  most  species  of  grouse  to  seek  the  vicinity  of  drinking  water 
in  late  summer  and  fall,  but  whether  they  do  this  out  of  choice  or  necessity 
is  not  known. 

The  early  summer  movement  of  young  and  adult  Attwater's 
prairie  chickens  also  was  to  the  vicinity  of  surface  water,  but  it 
was  to  water  near  which  there  also  was  shade.  Pastures  having  an 
abundance  of  surface  water  but  little  or  no  shade-producing  cover 
had  few  if  any  birds  after  mid-June.  Likewise,  places  in  which 
dense  stands  of  weeds,  shrubs,  or  tall  grass  were  abundant,  but  sur- 
face WEiter  scarce,  were  sparsely  populated.  More  than  95  percent  of 
the  more  than  500  Attwater's  prairie  chickens  observed  from  June 
24  through  September  4,  1937,  were  in  heavy  cover  within  a  mile, 
generally  within  less  than  half  a  mile  of  surface  water. 

The  beginning  of  the  summer  movement  is  synchronous  with  the 
drying  up  of  the  wild  indigo  {Baptisia^  pi.  7),  a  plant  that  fur- 
nishes the  principal  shade  on  burns  and  heavily  grazed  areas  from 
April  through  May.  Prairie  chickens  require  abundant  shade  in  sum- 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


PLATE  7 


B5068S:  B49718A 


Above,  Wild  indigo  (Baptisia)  in  a  closely  grazed  pasture;  Austin  County,  Tex., 
approximately  8  miles  southeast  of  Sealy,  April  10,  1938.  Below,  Shocked 
grain  and  waste  in  rice  fields  sometimes  attract  prairie  chickens;  Colorado 
County,  Tex.,  3  miles  northeast  of  Eagle  Lake,  September  5,  1936.  (Photos 
by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN 


23 


mer,  for  birds  that  were  herded  from  such  cover  at  midday  panted 
vigorously,  drooped  their  wings,  and  showed  other  signs  of  discomfort. 
They  evidently  rarely  drink  from  surface  water.  In  1937,  birds 
near  water  were  closely  observed,  but  only  one  was  seen  to  drink 
during  the  entire  summer.  That  was  in  Colorado  County  on  June 
1,  1937,  when  a  chick  about  3  weeks  old  drank  a  few  times  from  a 
puddle  formed  by  water  from  a  leaking  windmill.  The  soft  mud 
bordering  ponds  in  inhabited  prairie  chicken  range  in  Brazoria, 
Colorado,  and  Austin  Counties  was  examined  thoroughly  at  various 
times,  but  tracks  of  this  species  were  never  found.     Grasshoppers 


FiGxmE  2. — Movements  of  a  combined  brood,  May  1  to  July  26,  1937,  Colorado 
Comity.  Birds  seen  in  areas  as  follows :  1,  May  1  to  28 ;  2,  June  10  to  July 
10;  3,  July  15  to  26. 

and  other  favorite  foods  were  frequently  more  abundant  in  summer 
in  heavy  cover  near  water,  but  the  food  factor  was  not  thought  to 
be  of  great  importance  at  the  time.  The  summer  movements  of 
prairie  chickens  to  heavy  cover  near  water  are  not  satisfactorily  ex- 
plainable on  the  basis  of  cover,  water,  and  food,  but  these  habitat 
conditions  must  be  provided  where  stable  populations  are  desired. 
After  they  found  a  satisfactory  summer  range,  the  prairie  chickens 
moved  little  until  fall,  unless  their  summer  territory  was  depleted 
or  that  nearby  was  more  suitable.  The  population  of  a  460-acre 
pasture  in  Colorado  County  remained  at  nearly  the  same  level  (25 


24      NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

to  36  birds)  from  July  26  through  September  3,  1937.  The  birds 
that  rested  in  this  area  at  noon  each  day,  however,  foraged  and 
roosted  largely  in  adjoining  pastures,  but  their  range  was  never  more 
than  114  miles  and  usually  under  half  a  mile. 

Rains  in  1937  sufficiently  heavy  to  collect  in  low  spots  caused  tem- 
porary spreading  of  prairie  chickens  from  previously  occupied  areas. 
As  the  temporary  water  disappeared,  however,  the  birds  again  con- 
centrated. 

Faix  and  Winter 

Populations  that  had  been  rather  stable  in  certain  pastures  in  Colo- 
rado County  during  the  summer  months  of  1937  began  shifting  early 
in  fall.  About  25  birds  that  were  summer  residents  of  the  M.  Shin- 
dler  cotton  field  from  July  through  August  were  absent  after  Sep- 
tember 4.  Two  thousand  acres  of  regularly  censused  pasture  where 
prairie  chickens  were  common  in  summer  contained  only  9  birds  when 
rope  counted  on  October  22.  While  the  birds  decreased  generally 
in  the  large  pastures,  they  increased  around  small  farms  near  Sealy, 
Austin  County ;  Lissie,  Wharton  County ;  and  Bernardo  and  Chester- 
ville,  Colorado  County — ^territory  5  to  10  miles  removed  from  the 
pastures  in  which  birds  had  been  most  common  during  the  preceding 
spring  and  summer. 

Distances  traveled  daily  were  evidently  great  in  some  instances.  A 
bird  killed  by  a  farmer  at  8  a.  m.  on  September  1,  1936,  was  known 
to  have  traveled  at  least  3  miles  since  dawn,  because  its  crop  was 
filled  with  rice  and  the  nearest  rice  field  was  that  distant.  Two  in- 
dividuals, observed  for  2  hours  on  the  afternoon  of  October  22,  1937, 
traveled  approximately  1%  miles  southeast  of  the  point  where  first 
seen.  When  finally  flushed,  they  flew  an  additional  2  miles  or  so  in 
the  same  direction.  A  flock  of  four  birds  observed  from  4  p.  m.  to 
6:15  p.  m.  on  January  4,  1938,  traveled  more  than  1%  miles.  The 
movement  was  in  a  circular  direction,  however,  for  at  nightfall,  the 
birds  were  less  than  half  a  mile  from  the  point  where  they  were  first 
observed.  Cool  weather,  fall  rains,  and  a  seasonal  abundance  of 
food  and  cover,  especially  in  the  vicinity  of  farming  commrmities, 
probably  were  important  in  promoting  the  general  fall  scattering 
and  the  long  daily  trips  the  prairie  chickens  made  in  territory  that 
was  sparsely  populated  at  other  seasons.  The  birds  reconcentrated 
in  large  pastures,  however,  as  fall  passed  into  winter. 

The  population  of  the  Everett  pasture  (640  acres),  Colorado 
County,  increased  from  November  3,  1937,  through  January  28,  1938 ; 
five  censuses  during  that  period  showing  46,  58,  56  to  58,  73,  and  84 
birds,  respectively.  Excellent  food  and  cover  conditions  prevailed, 
for  the  area  was  lightly  grazed.  This  increase  in  the  number  of 
birds  apparently  resulted  from  influxes  from  adjoining  areas.    After 


ATTWATER'S  PRAIRIE   CHICKEN  25 

November  15,  few  fluctuations  in  numbers  between  different  pastures 
were  reported  by  fence  riders  and  others.  Pastures  that  contained 
the  greatest  numbers  in  November  and  December  1937  also  harbored 
the  largest  breeding  populations  the  following  spring. 

The  data  at  hand  show  that  late  in  fall,  probably  by  about  Novem- 
ber 15,  the  prairie  chickens  move  to  pastures  where  food  and  cover 
conditions  are  adequate.  Having  found  such  an  area,  they  remain 
until  spring.  Probably  the  best  way  to  attract  a  good  breeding 
population,  therefore,  is  to  provide  suitable  food  and  cover  conditions 
during  the  preceding  winter. 

FOOD 

Data  on  the  food  of  Attwater's  prairie  chicken  were  derived  mainly 
from  analyses  of  21  stomachs  (crops,  or  gizzards,  or  both)  and  more 
than  200  droppings  (scats).  Additional  information  was  obtained 
by  watching  feeding  birds  at  close  range  through  field  glasses.  Of 
the  21  stomachs,  18  were  of  adult  prairie  chickens,  2  of  chicks  ap- 
proximately 10  days  old,  and  1  of  a  juvenile  about  7  weeks  old. 
Specimens  were  obtained  as  follows:  6  in  winter  (January  and 
February),  6  in  spring  (April  and  May),  5  in  summer  (June  through 
August),  and  5  in  fall  (September  through  November).  J.  H.  Gaut 
collected  3  stomachs  near  East  Bernard,  Wharton  County,  in  May 
1905.  Over  the  period  beginning  September  1936  and  ending  Au- 
gust 1938,  2  stomachs  were  obtained  in  Austin  County,  4  in  Eefugio 
County,  and  12  in  Colorado  County.  As  the  crops  and  gizzards 
of  all  birds  found  killed  by  automobiles,  predators,  poachers,  and 
from  other  causes  were  saved,  it  was  necessary  to  collect  only  11 
specimens  to  balance  the  series  according  to  seasons. 

Except  during  the  breeding  season,  adult  prairie  chickens  regu- 
larly feed  twice  daily,  early  in  the  morning  (dawn  to  about  8  a.  m.), 
and  late  in  the  afternoon  (4  p.  m.  to  dark) .  Occasional  bits  of  food 
are  picked  up  throughout  the  day,  but  the  gullets  of  specimens  col- 
lected about  noon  are  usually  empty  or  nearly  so.  The  food  capacity 
of  prairie  chickens  is  large.  Gullets  frequently  contain  about  20 
cubic  centimeters,  and  the  gizzard  about  30  cubic  centimeters,  of 
material.  Since  the  birds  ordinarily  feed  slowly  and  deliberately, 
apparently  selecting  their  food  with  great  care,  it  is  not  surprising 
that  their  diet  in  favorable  areas  is  varied.  Stomachs  have  been 
examined  that  contained  29  kinds  of  food  and  more  than  1,300  items ; 
stomachs  rarely  contain  less  than  13  kinds  of  food  of  500  items. 
Mature  birds  evidently  feed  mostly  on  vegetation  at  all  seasons, 
for  the  stomachs  of  18  adults  (table  6,  p.  26)  contained  88.28  percent 
of  plant  material  and  11.72  percent  of  insects.  Animal  matter  prob- 
ably ranks  higher  than  plants  in  the  diet  of  young  birds,  however, 


26      NORTH  AMERICAN  FAUNA    57,   FISH  AND   WILDLIFE    SERVICE 

for  the  stomachs  of  2  chicks  and  a  juvenile  (table  7,  below)  contained 
88.5  percent  of  insects.  The  ratio  of  plant  to  animal  food  varies 
according  to  season  (table  8,  below),  insects,  for  instance,  apparently 
being  eaten  in  greatest  quantity  in  summer. 

Table  6. — Composition  of  the  stomach  ^  contents  of  18  adult  prairie  chickens 


Item 

Stomachs 

in  which 

found 

Quantity 
present 

Item 

Stomachs 

in  which 

found 

Quantity 
present 

Number 

18 

12 

16 

5 

6 

Percent 

88.  S8 

27.  n 

55.67 

1.30 

4.20 

Animal  matter - 

Number 
18 

17 
8 
1 
1 

11 

Percent 

11.711 

Leaves  and  stems 

Seeds  and  pods 

Buds  and  flowers 

Miscellaneous  * 

Insects: 

Adults 

10.83 

Eggs  and  larvae. - 

Round  worms 

Prairie  chicken  feathers... 
Grit 

0.89 
W 
(') 
(») 

'  Crops  or  gizzards,  or  both. 

»  Woody  pod  septa,  root  stocks,  and  the  like. 

s  Trace. 

Table  7. — Composition  of  the  stomach  contents  of  three  younff  prairie  chickens 


Item 

Stomachs 

in  which 

found 

Quantity 
present 

Item 

Stomachs 

in  which 

found 

Quantity 
present 

Vegetable  matter 

Number 
2 
2 
1 

Percent 
11.5 
1.5 
10.0 

Animal  matter 

Nuviber 
3 

3 
2 

Percent 

88.6 

Seeds  or  pods ... 

Insects: 

Adults 

86.0 

Eggs  or  larvae 

2.5 

Table  8. — Percentage  of  plant  and  animal  food  according  to  season 


Item 

Spring 

Summer 

FaU 

Winter 

Whole  year 

Plants             - 

94.25 
5.75 

71.0 
29.0 

85.8 
14.2 

95.0 
6.0 

86.51 

13.49 

Total  .  . 

100. 00 

100.0 

100.0 

100.0 

100.00 

The  data  at  hand  indicate  that  Attwater's  prairie  chickens  are 
preponderantly  granivorous,  for  seeds  and  seed  pods  made  up  slightly 
more  than  50  percent  of  all  the  material  in  the  stomachs  of  18  adults. 
Much  succulent  vegetation  is  eaten,  however,  including  leaves,  buds, 
flowers,  and  root  stocks.  The  birds  also  consume  insect  eggs,  larvae, 
and  adults,  as  shown  in  tables  6  and  7. 

Parts  of  some  50  kinds  of  plants  and  more  than  65  species  of 
insects  were  identified  in  the  food  from  stomachs  or  scats,  or  by 
observations  in  the  field.  The  names  of  these  plants  and  insects 
together  with  the  seasons  when  they  are  known  to  be  eaten,  are 
listed  in  tables  9  and  10,  pp.  27  and  28. 


ATTWATER'S   PRAIRIE    CHICKEN 
Table  9. — Plant  foods  (56)  of  Attioatefs  praiiHe  chicken 


27 


Plant 


Marsileaceao:  Pepperwort  (MarsUea)... 

Poaceae: 

Paspalum  (Paspatum  citiatifotium  type)  _  . 

Bull  grass  {Paspaium  boscianum  ?) 

Paspalum  {Paspaium  plicatulum) 

Panic  grass  (Panicum  scribnerianum) 

Panic  grass  (Panicum  spp.) 

Crabgrass  (Digitaria) 

Sandbur  (Cenchrus) 

Hegari  (Sorghum  vulgare) 

Rice  (Oryza  sativa) 

Corn  (Zea  mags) 

Cyperaceae: 

Beakrush  (Rynchospora) 

Sedge  (Carex) 

Commeliuaceae:  Dayflower  (Commelina  cris- 
pa). 

Alliaceae:  Wild  onion  (Nothoscordum  bivalve) .  _  _ 

Liliaceae:  (Undetermined) 

Leucojaceae:  Stargrass  (Hypoxis) 

Convallariaceae:  Solomons  seal  (Polygonatum 
commutatum) . 

Ixiaceae:    Blue-eyed-grass   (Sisyrinchium   va- 
rians). 

Polygonaceae:  Dock  (Rumex  near  crispus  type), 

Ranunculaceae:  Buttercup  (Ranunculus  near 
hispidus). 

Rosaceae:  Dewberry  (Rubus).. 

Malaceae:  Chokeberry  (Pyrus) 

Mimosaceae: 

Sensitive  briar  (Neptunia  lutea).- 

Mimosa  (Mimosa) 

Acacia  (Acacia) 

Cassiaceae:  Partridge-pea  (Chamaecrista  fas- 
ciculata) . 

Fabaceae: 

Wild  pea  (undet.) 

Wild  pea  (Lathyrus  pusillus) 

Peanuts  (Arachis  hypogaea) 

Oxalidacoae:  Woodsorrel  (Oxalis)-. 

Euphorbiaceae: 

Doveweed  (Crofon  capitatus). 

Doveweed  (C.  glandulosus) 

Doveweed  (C.  monanthogynui) 

Spurge  (Euphorbia) 

Spurge  (Crotonopsis  linearis) 

Spurge  (Chamaesyce) 

Vitaceae:  Grape  (Vitis) 

Malvaceae:  Mallow  (Malva). 

Epilobiaceae:  Oaura  (Oaura) 

Ammiaceae  (Cynosciadium) 

Convolvulaceae: 

Bindweed  (Convolvulus) _ 

Evolvulus - - -- 

Polemoniaceae:  Phlox  (Phlox  drummondi) 

Boraginaceae:  Gromwell  (Lithospermum) 

Verbenaceae: 

Fog  fruit  (Phyla  nodiflora) 

Verbena  (Verbena) 

Aeanthaceae:  Ruellia    (Ruellia    ciliosa    var. 
humilis). 

Rubiaceae: 

Buttonweed  (Diodia  teres) 

Buttonweed  (Diodia  virginiana) 

Bedstraw  (Galium) 

Ambrosiaceae: 

Marsh-elder  (Iva  ciliata) 

Perennial  ragweed  (Ambrosia psilostachy a). 

Carduaceae: 

Thistle  (Carduus) 

Tickweed  (Coreopsis) 

Cichoriaceae:  (Serinea  oppositifolia) 


Parts  eaten 


Leaves. 


Leaves,  seeds. 

Seeds. 

..._do 

do. 

do 


.do. 
.do. 
.do. 
.do. 
.do. 


do 

Seeds,  leaves.. 
Leaves,  seeds. 


Leaves,  flowers. 

Seeds 

Leaves,  seeds... 
Seeds 


Seeds,  pods. 


Seeds , 

Leaves,  seeds,  pods. 


Seeds,  fruits 

Flowers,  fruits. 


Leaves,  flowers,  seeds. 

Leaves,  seeds 

Seeds 

Seeds,  flowers 


Flowers 

Leaves... 

Fruits... 

Leaves,  seeds. 


Seeds 

do 

Seeds,  leaves. 

Seeds 

do 


do 

Seeds,  fruits. 
Seeds,  pods.. 

Pods.. 

Leaves. 


Seeds 

Seeds,  pods 

Seeds,  pods,  flowers. 
Seeds 


Leaves,  flowers,  fruit... 
Leaves.- 

Leaves,    stems,    seeds 
buds,  pods,  flowers. 


Seeds 

do_ 

Leaves,  seeds. 


do. 

Seeds. . 


do 

Flowers 

Seeds,  pods. 


Seasons  when 
eaten  i 


Wi 

Sp,  su,  au,  wi 

Au 

Sp,  su,  au 

Sp. 

Sp 

Au 

Wi 

Su,  au 

Au,  wi 

Sp... 

Su,  au,  wi 

Au 

Au.... 

Wi_ 

Su,  wi.. 

Sp- 

Su... 

Sp,  su 

Wi... 

Wi,sp-. 

Sp-.. 

Sp 

Au,  wi,  sp 

Su,  au,  wi 

Wi 

Su,  au.. 

Sp-. 

Wi.. 

Au 

Wi,  sp,  su 

Au,  wi 

Au,  wi 

Au 

Au,  wi,  sp 

Au 

Au 

Su 

Sp 

Sp 

Wi 

Sp 

Sp 

Sp,  su 

Su 

Sp,  wi,  au 

Wi... 

Au,  wi.. 

Su,  au,  wi 

Su 

Sp,  su,  au 

Wi.. 

Au,  vri 

Sp. 

Sp 

Sp,  su 


Source  of 
data' 


St. 

St,  sc. 

St. 

St. 

St. 

St. 

St. 

St. 

Si. 

Si,  St. 

St. 

St. 
St. 
St. 

St. 
St. 

St,  si. 
St. 

St. 

St. 
St. 

St. 
St,  si. 

St,  si. 
St,  sc. 
St. 
St,  si. 


St. 
St. 
Si. 
St,  sc,  si. 

St,  sc,  si. 

St. 

St,  si. 

St,  sc. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 
St,  sc. 

St. 

St,  si, 

St. 

St,  sc,  si. 


St,  se. 
St. 
St,  sc. 

St,  si. 
St,  sc. 

St. 
Si. 
St,  sc. 


1  Abbreviations  of  seasons:  Sp,  spring;  Su,  summer;  Au,  autumn;  and  Wi,  winter. 

2  Abbreviations  of  sources:  St,  stomach  examination;  Sc,  scat  examination;  and  Si,  sight  record. 

303807' 


28      NORTH  AMERICAN   FAUNA    5  7,   FISH  AND  WILDLIFE    SERVICE 
Tasle  10. — Some  insect  foods  (68)  of  Attwater's  prairie  chicken 


Name 


Araneida: 

Spider  (Lycosidae)__- 

Spider  (undetermined) 

Orthoptera; 

Grasshopper  (Cyrtaeanthacrinae) 

Pigmy  locust  (Aerydinae) 

Grasshopper  (Syrbula) 

Grasshopper  (Oedipodinae) --. 

Western  grasshopper  (Melanoplus  ciner- 

eus). 
Green    grasshopper    (Chortophaga    viridi- 
fasciata) . 

Grasshopper  (Oedipodinae) 

Grasshopper  (Schistocerca  americana) 

Grasshopper  (SaUatoria) 

Meadow  grasshopper  (Conocephalus) 

Long-horned  grasshopper  (Tettigoniidae) . 

Hemiptera: 

Shield  bug  (Pentatomidae) 

Bug  (undetermined  Hemiptera) 

Stinkbug  (Euschisfus) 

Homoptera: 

Leafhopper  (Cicadellidae)--. — 

Lantern  fly  (Fulgoridae). — . 

Soft  scale  (Leucanium) 

Coleoptera: 

Weevil  {Graphorhinus  vadosus), -.. 

Weevil  {Lixus) 

Weevil  (Thecesternus  humeralis)-. 

Billbug  (Sphenophorus  minimus) 

Billbug  {Sphenophorus  bartramiae) 

Billbug  {Sphenophorus  germari) 

Billbug  {Sphenophorus) 

Weevil  {Boris) 

Weevil  {Hyperodes) 

Rice-water  weevil  {Lissorhoptrus  simplex). 

Weevil  {Pachyphanes) 

Weevil  {Anthonomus  fulvus) 

Snout  beetle  (Curculionidae) 

.     Weevil  {Apion) 

Scarred  snout  beetle  ( Tanymecus  lacaena)  _ 
Scarred  snout  beetle  {Eudiagogus  pulcher) 
Scarred  snout  beetle  {Compsus  auricepha- 


Leaf  beetle  {Phaedon  viridis)... 

Leaf  beetle  {Cryptocephalus  venustui) 

Leaf  beetle  ( Cryptocephalus) 

Leaf  beetle  {Zygogramma  disrupta) 

Leaf  beetle  (Oedionychis  petaurista) 

Leaf  beetle  {Metacroma  ustum) 

Leaf  beetle  {Disonycha) 

Leaf  beetle  (Chrysomelidae) 

Leaf  beetle  {Calligrapha  similis) 

Leaf  beetle  {Graphops  pubescens) 

12-spotted    cucumber    beetle    {Diabrotica 
duodecimpunciaia) . 

May  beetle  {PhyUophaga) 

May  beetle  (Scarabaeidae) 

Leaf  chafer  {Anomala  ludoviciana) 

Dung  beetle  {Aphodius  sp.) 

Ground  beetle  (Triplecfrus) 

Ground  beetle  {Eumolops) 

Ground  beetle  (Carabidae) 

Ground  beetle  (Chlaenius) 

Darkling  beetle  (Tenebrionldae) 

Lepidoptera: 

Moths,  butterflies,  and  skippers  (3  spe- 
cies) . 
Salt-marsh  caterpillar  {Estigmene  acraea).. 

Diptera: 

Gall  gnat  (Cecidomyiidae) 

Robber  fly  {Asilus) - 

Hymenoptera: 

Gall  fly  (Gynipidae) 

Chalcid  fly  (Ghalcidae)... 

Paper  wasp  (Polistes) .- 

Ant  {Odontomachus  haemotodes) 

Ant  {Pheidole  sp) 

Fire  ant  {Solenopsis  sp.) .- 


Form  eaten 


Adult.. 
do- 


do 

Adult,  larva. 
do 


_do- 
-do. 


-do- 


do 

do 

do 


do 

Adult,  larva,  egg. 


Adult Sp. 

Adult,  eggs Sp- 

Adult Su. 


.do- 
.do.. 
.do- 


.do. 
-do- 
.do. 


-do- 
.do- 
.do. 
.do. 
.do. 
.do- 


_do_ 
.do. 
-do. 


-do. 
.do. 
.do. 
.do. 
.do. 


.do. 
.do. 
.do. 


.do. 
.do. 
.do. 


.do- 
.do- 
.do. 
-do. 
.do. 


.do.... 

.do 

.do.--. 

-do 

-do 

-do 

-do 

-do--.. 
-do 


Adult,  larva, 
---do 


Larva. 
Adult. 


Adult,  eggs 

Adult.-.. 

Adult,  pupa  eases. 

Adult 

....do 

....do... 


Seasons  when 
eaten  i 


Au 

Su,  au- 


Sp,  su 

Sp,  su,  au- 
Au 

Au 

Su,  au 


Su. 


Su 

Su 

Su 

Sp,  su,  au. 
Su,  au 


Wi,  sp. 
Su,  wi- 

Wi 

Sp----. 
Sp,  au- 
Sp,  au- 
Su,  wi- 
Sp,  su.. 
Sp.-... 

Sp 

Sp-.-.. 
Sp....- 
Sp,  su.. 

Wi 

Wi 

Au 

Sp..... 


Wi 

Su,  au 

Su 

Su,  au 

Au 

Au 

Sp,  su,  wi. 
Sp,  su,  au. 

Wi 

Wi 

Wi 


Sp..- 
Su,  au. 
Au 


Au,  wi 

Wi 

Sp,  su,  au. 

Su 

Au 


Su,  au. 
Su,  au. 


Sp. 
Au. 


Sp..... 

Su 

Su,  wi. 

Wi 

Su 

Su 


>  See  footnote  1,  table  9. 
'  See  footnote  2,  table  9. 


Au,  wi,  sp St. 

Sp,  su,  wi. St. 

Au St,  sc. 


ATTWATER'S   PRAIRIE    CHICKEN  29 

Native  plants  are  the  most  important  source  of  food  for  the 
prairie  chicken.  Rated  according  to  frequency  of  occurrence  in 
stomachs  and  scats,  gross  bulk,  and  periods  of  availability,  ruellia 
{Ruellia)  appears  to  be  by  far  the  most  important  single  food.  It 
occurred  in  13  of  the  18  stomachs  and  made  up  almost  27  percent 
of  all  the  material  eaten.  Stargrass  {Hypoxis) ,  bedstraw  {Galium)^ 
doveweed  ( 6^rc>z^cn) ,  perennial  ragweed  {Ambrosia  psilo'Stachya)  also 
were  eaten  freely  through  long  seasons.  Practically  all  the  impor- 
tant food  plants  utilized  by  the  prairie  chicken  grow  naturally  in 
pastures  that  are  moderately  grazed.  Corn  was  the  only  cultivated 
grain  found,  and  the  small  quantity  present  was  probably  waste. 
It  is  known,  however,  that  prairie  chickens  are  fond  of  certain  crops, 
especially  peanuts,  hegari,  and  ripened  rice.  The  birds  frequently 
congregate  in  peanut  patches,  particularly  after  the  harvest,  and 
scratch  for  the  waste  pods.  They  also  use  conveniently  situated 
hegari  fields  extensively  in  summer,  but  the  good  shade  in  such 
areas  is  probably  as  attractive  as  the  grain.  Prairie  chickens  also 
range  into  rice  fields  after  the  crop  is  cut  and  shocked,  and  they 
sometimes  feed  on  the  grain  in  the  shock  as  well  as  on  that  so  freely 
wasted  on  the  ground  (pi.  7).  The  rice  taken  from  shocks  usually 
is  not  objectionable,  although  L.  D.  Roberts,  Eagle  Lake,  Tex., 
reports  that  he  saw  approximately  1,500  of  the  birds  feeding  in  a 
single  field  of  about  500  acres  in  the  Egypt  section,  Wharton  County, 
in  September  1920.  By  scratching,  the  prairie  chickens  loosen  the 
shocks,  thus  allowing  moisture  to  seep  in,  and  this  causes  some  com- 
plaint. A  large  increase  of  prairie  chickens  might  conceivably  bring 
on  control  problems  in  certain  areas.  The  difficulties  would  prob- 
ably not  be  serious,  however,  because  the  birds  could  easily  be 
frightened  by  shotgun  fire  or  by  other  disturbances,  and  they  quickly 
desert  areas  of  potential  danger. 

Among  insect  foods  of  Attwater's  prairie  chicken,  11  grasshoppers 
(6  identified  to  genus  or  species)  are  especially  prominent;  32 
beetles  (identified  to  genus  or  species,  including  16  weevils)  also 
are  important.  The  vast  majority  (50  of  65)  of  the  insects  eaten 
by  prairie  chickens  are  kinds  neutral  (25)  or  harmful  (25)  to 
agriculture.  Field  observations,  and  reports  of  cooperators,  show 
that  prairie  chickens  eat  in  large  quantities  the  moths  of  the  cotton 
leaf  worm  {Alabcmm  argillacea),  one  of  the  worst  insect  pests  in 
the  coastal  area.  Under  ordinary  conditions,  the  food  habits  of 
Attwater's  prairie  chicken,  considering  both  insect  and  plant  con- 
sumption, are  such  as  to  make  it  one  of  the  most  valuable  birds  of 
farm  and  range. 


30       NORTH  AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

HABITAT  REQUIREMENTS 
KIND  OF  HABITAT  BEST  SUITED 

The  coastal  prairie  grassland  is  the  real  home  of  Attwater's 
prairie  chicken,  particularly  in  areas  characterized  by  diversity  of 
vegetation  (pi.  8).  Woodland,  brushland,  and  cultivated  land  each 
furnish  some  food  and  cover  at  certain  times  and  under  certain 
conditions,  but  use  of  these  types  is  optional  with  the  prairie  chicken, 
not  vital.  These  secondary  habitats  are  frequented  mostly  when  food 
and  cover  are  at  the  annual  peak,  as  in  September  and  October, 
but  are  little  used  at  times  of  seasonal  scarcity,  as  in  December, 
January,  February,  and  early  in  March.  Wooded,  cultivated,  and 
brushy  areas,  individually  or  in  combination,  contribute  little  or 
nothing  as  courtship  grounds  and  nesting  cover.  Properly  managed 
grassland  (pi.  9),  however,  satisfies  every  known  requirement  of 
Attwater's  prairie  chicken,  and  management,  therefore,  should  be 
directed  toward  improvement  of  these  areas. 

CHARACTER  AND  DENSITY  OF  VEGETATION 

Optimum  food  and  cover  conditions  seemingly  are  approached 
when  the  prairie  vegetation  is  varied  in  species,  interspersion,  and 
density.  The  plant  life  of  well-populated  areas  includes  a  variety 
of  grasses,  sedges,  rushes,  and  legumes,  and  tall  weeds  or  their  cover 
equivalent  in  the  form  of  scattered  clumps  of  myrtle  or  live-oak 
brush.  The  combination  and  density  of  the  plants  in  the  most 
favored  places  invariably  is  such  as  to  provide  cover  in  all  degrees 
and  well  distributed. 

Light  cover  serves  (1)  exclusively  for  the  courtship  performance, 
(2)  for  feeding  at  all  seasons,  and  (3)  for  a  resort  when  dew  is 
heavy  or  after  rains.  Light  to  medium  heavy  cover  is  used  (1)  for 
roosting,  especially  on  gentle  slopes,  (2)  by  chicks  under  5  weeks  old, 
and  (3)  for  feeding  by  adults  throughout  the  year.  Cover  of  a 
medium  heavy  to  heavy  character  (pi.  9)  is  utilized  (1)  extensively 
for  nesting,  (2)  as  a  loafing  cover  except  during  the  hot  summer 
months,  and  (3)  as  feeding  grounds  and  escape  cover  in  emergencies. 
Heavy  cover  (pi.  9)  is  essential  (1)  for  shade  in  summer,  (2)  for 
protection  against  unfavorable  weather  and  predators  at  other  sea- 
sons, and  (3)  as  a  source  of  food,  especially  in  fall. 

TOPOGRAPHY 

Kichness  and  variety  in  the  vegetation  are  promoted  by  even  slight 
variations  in  topography  and  soil  (pi.  8).  Consequently,  the  best 
natural  range  for  Attwater's  prairie  chicken  comprises  country  in 
which  knolls,  ridges,  or  hog  wallows,  are  frequent.    Further,  knolls 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate 


ik.w$^  ^^ 


,yi, 


B49728;  B50016 


Above,  Diversified  cover — excellent  prairie  chicken  range;  Colorado  County, 
Tex.,  approximatelj'  7  miles  northeast  of  Eagle  Lake,  September  4,  1936. 
Below,  Diversity  of  topography  and  vegetation;  Austin  County,  Tex.,  approxi- 
mately 6  miles  northeast  of  Bellville,  June  13,  1936.  (Photos  by  V.  W.  Leh- 
mann.) 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  9 


Above,  Medium-heavy  to  heavy  cover — excellent  food-cover  conditious  in  a 
moderately  grazed  pasture;  Colorado  County,  Tex.,  approximately  8  miles 
north  of  Eagle  Lake,  December  21,  1936.  Below,  Heavy  cover,  mostly  myrtle 
brush,  near  stream- — excellent  summer  range;  Austin  County,  Tex.,  approxi- 
mately 4  miles  east  of  Bellville,  July  14,  1936.      (Photos  by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN  31 

and  ridges  are  least  likely  to  be  inundated  in  times  of  flood  and  they 
afford  the  birds  better  opportunity  of  eluding  their  natural  enemies 
and  man. 

WATER 

The  balanced  prairie  chicken  habitat  should  offer  a  generous  supply 
of  surface  water  throughout  the  year.  Although  Attwater's  prairie 
chickens  may  not  be  dependent  on  free  water  for  survival  during 
normal  years  (see  p.  23),  it  has  been  established  that  their  favorite 
summer  range  is  rather  well  watered.  During  unusually  dry  years 
such  as  occurred  in  Refugio  County  in  1917,  surface  water  may  be 
an  absolute  necessity.  Also,  through  its  effects  on  vegetation  and 
insect  life,  water  is  necessary  for  the  maintenance  of  optimum  cover 
and  food  conditions.  The  water  supply  of  prairie  chicken  areas 
apparently  is  about  optimum  when  permanent  sources  are  available 
throughout  the  range  at  intervals  not  greater  than  a  mile. 

Briefly,  then,  habitat  conditions  for  Attwater's  prairie  chickens 
seemingly  approach  the  ideal  in  grassland  area  when  (1)  the  vegeta- 
tion is  diversified  and  native  grasses,  sedges,  legumes,  and  small  and 
large  weeds,  or  their  equivalent  in  the  form  of  brush  or  dwarfed  trees, 
are  present  in  such  stands  as  to  provide  all  densities  of  cover;  (2) 
knolls,  ridges,  and  hog  wallows  are  frequent  and  the  soils  vary  from 
loose  sand  to  tight  clay  or  silt;  and  (3)  permanent  sources  of  surface 
water  are  available  not  more  than  a  mile  apart. 

SEASONS  OF  SCARCITY 

In  evaluating  the  suitability  of  an  area  for  Attwater's  prairie  chick- 
ens it  is  to  be  kept  in  mind  that  its  productivity  or  carrying  capacity 
is  not  determined  by  conditions  during  the  best  season  in  a  good  year. 
Rather,  as  Taylor  (1934)  states,  conditions  that  prevail  during  the 
most  critical  season  of  the  year  and  in  the  most  extreme  year  in  a 
series  of  years  determine  carrying  capacity.  In  the  coastal  country  of 
Texas  the  season  of  scarity,  or  the  period  when  food  and  cover  are  at 
a  minimum,  normally  is  from  December  through  early  March.  The 
most  critical  years  are  those  of  heavy  rainfall  in  May. 

LIMITING  FACTORS 

Factors  that  have  contributed  to  the  decrease  of  prairie  chickens 
in  Texas  may  he  classed  roughly  as  (1)  natural,  including  unfavor- 
able weather,  predators,  and  disease;  and  (2)  artificial,  including 
cultivation,  heavy  grazing,  burning,  and  overshooting.  It  might 
be  more  accurate  to  class  limiting  factors  as  those  brought  about  by 
man,  directly  or  indirectly.  Although  it  is  not  generally  appre- 
ciated, the  decrease  of  prairie  chickens  in  coastal  Texas  corresponds 


32       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND    WILDLIFE    SERVICE 

with  the  spread  of  civilization.  Prior  to  the  coming  of  white  men, 
the  number  of  birds  probably  was  well  maintained,  but  there  was 
a  decrease  as  the  country  was  developed.  Attwater's  prairie  chicken 
will  become  extinct  unless  man  ceases  to  exploit  the  soil,  water,  and 
other  natural  resources  of  its  range. 

NATURAL  FACTORS 

Rainfall  Duiung  the  Nesting  Season 

Prairie  chickens  in  Texas  evidently  suffer  greatly  at  times  from 
extremes  of  weather.  Heavy  precipitation  during  the  nesting  and 
brooding  season  (March  through  June)  appears  to  be  an  especially 
serious  hazard,  as  indicated  by  the  studies  of  Waddell  and  others  in 
Colorado,  Austin,  and  Wharton  Counties.  From  1925  through  1937 
Waddell  estimated  the  size  of  the  annual  crop  of  young  prairie 
chickens  on  the  basis  of  the  number  of  birds,  both  young  and  old 
(1)  observed  on  almost  daily  trips  through  their  range,  (2)  seen  by 
reliable  resident  observers,  (3)  bagged  by  hunters,  and  (4)  counted  an- 
nually on  the  courtship  grounds  in  spring.  From  his  studies  he  con- 
cluded that  crops  of  young  prairie  chickens  were  (1)  good  in  spring 
months  when  rainfall  was  below  average,  (2)  fair  to  good  when 
rainfall  was  average  or  only  slightly  above  average,  and  (3)  poor, 
very  few  young  being  reared,  when  the  nesting  season  was  abnormally 
wet. 

Waddell's  impressions  as  to  the  correlation  between  the  amount  of 
precipitation  in  spring  and  the  size  of  the  amiual  crop  of  chickens 
were  tested  rather  thoroughly  in  1936  and  again  in  1937.  In  August 
1936,  after  a  reconnaissance  made  with  car  and  dog  (see  p.  52)  over 
approximately  25,000  acres  of  territory  in  Colorado  and  Austin 
Counties,  it  was  estimated  that  the  annual  increase  was  less  than  10 
percent.  Rainfall  there  was  below  average  in  March,  April,  and 
June  1936,  but  it  exceeded  10  inches,  or  approximately  twice  the  aver- 
age, in  May,  as  shown  by  the  records  of  the  Weather  Bureau  at 
Columbus,  situated  centrally  in  that  area.  In  1937,  when  records 
of  this  station  showed  that  rainfall  was  2  inches  or  more  below 
average  in  April,  May,  and  June,  rope  counts  made  of  3,450  acres 
both  before  and  after  the  breeding  season  revealed  a  95-percent  in- 
crease, supporting  Waddell's  estimate  that  the  increase  was  good 
in  a  dry  season. 

In  table  11,  p.  33,  Waddell's  estimates  of  the  favorableness  of  the 
years  from  1925  through  1937  for  prairie  chicken  reproduction  are 
presented  together  with  precipitation  records  of  the  Columbus 
Weather  Bureau  Station  for  March,  April,  May,  and  June  in  those 
years. 


ATTWATER'S    PRAIRIE    CHICKEN 


33 


Table)  11. — Reproductive  yield  of  AtHvater's  prairie  chicken  in  relation  to  spring 
rainfall  in  inches  *  in  the  Colorado  County  area  ^ 


Estimated 
yield 

March 

April 

May 

June 

Year 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

1925 

1926     

Good 

Fair... 

0.33 
11.54 
3.49 
1.42 
4.54 
2.34 
3.84 
3.63 
2.36 
3.91 
3.72 
1.23 
6.01 

-2.50 

-8.71 

.66 

-1.41 

1.71 

-.49 

1.01 

.80 

-.47 

1.08 

.89 

-1.60 

3.15 

0.99 
7.86 
4.00 
3.76 
2.58 

.48 
1.43 
2.19 
1.43 
4.28 
4.58 
3.48 

.52 

-2.74 
4.13 

.27 

.03 

-1.15 

-3.25 

-2.30 

-1.54 

-2.30 

.55 

.85 

-.25 

-3.21 

2.87 
4.10 

1.24 
2.00 

16.12 
3.11 
1.98 
.66 
3.67 
1.90 
9.21 

10.65 
.47 

-1.51 

-.28 

-3.14 

-2.38 

11.74 

1.27 

-2.40 

-3.72 

-.71 

-2.48 

4.83 

6.27 

-3.91 

1.06 
3.37 

6.43 

8.52 

.99 

.89 

.90 

3.68 

1.40 

.22 

2.48 

.79 

1.37 

-2.12 
.19 

1927 

1928 

1929     

Good... 

do 

Poor 

Fair 

Good 

do 

Fair     

3.25 

5.34 

-2.19 

1930 

1931             

-2.29 
-2.28 

1932 

1933 

.50 
-1.78 

1934 

Good 

Poor. 

do 

Good 

-2.96 

1935 

1936 

1937             -  . 

-.70 
-2.39 
-1.81 

I  Records  of  U.  S.  Weather  Bureau  Station,  Columbus,  Colorado  County. 

'  Colorado  County,  north  central  Wharton  County,  southwestern  Austin  County. 

Waddell  found  good  crops  of  young  birds  in  the  Eagle  Lake  area 
in  1925,  1927,  1928,  1931,  1932,  1934,  and  1937,  years  when  rainfall 
in  May  was  1.5  inches  or  more  below  average.  Fair  crops  of  young 
prairie  chickens  were  thought  to  have  been  reared  in  1926,  1930, 
and  1933,  when  rainfall  in  May  was  approximately  average  (0.28 
below  in  1926)  to  only  slightly  above  (1.27  above  in  1930).  Poor 
crops  were  matured  in  1929,  1935,  and  1936,  when  May  precipitation 
was  appreciably  above  (approximately  twice)  the  average  for  that 
month.  Unusually  heavy  or  light  precipitation  in  March,  April,  or 
June  evidently  had  little  influence  on  the  broods  of  young,  for  good 
crops  were  recorded  in  1927,  when  rainfall  was  decidedly  above 
average  in  June,  and  a  poor  crop  is  known  to  have  occurred  in  1936, 
when  rainfall  was  below  average  in  all  months  of  the  nesting  season 
except  May.  The  records  at  hand  suggest,  therefore,  that  the  rain- 
fall in  May  is  a  fairly  satisfactory  index  of  the  suitability  of  the 
year  for  the  reproduction  of  Attwater's  prairie  chicken  under  natural 
conditions.  Good  crops  usually  result  when  the  rainfall  in  May  is 
1.5  inches  or  so  below  average;  fair  crops  are  probable  when  it  is 
approximately  average  or  only  slightly  above ;  and  poor  crops  appear 
almost  a  certainty  when  the  rainfall  for  that  month  is  decidedly 
above  average. 

Rainfall  in  May  is  of  greater  significance  than  that  in  any  other 
month,  as  the  1937  and  1938  nesting  studies  showed  that  most  of  the 
chicks  hatch  in  May.  Those  hatched  in  April  do  not  yet  have  a 
serviceable  covering  of  feathers  by  May  and,  consequently,  are  almost 
as  vulnerable  to  the  rains  as  are  birds  hatched  in  that  month.  Nests 
flooded  in  March  and  April  may  be  rebuilt,  for  the  booming  season 
is  still  in  full  swing,  but  nests  flooded  after  May  1  are  seldom  re- 


34       NORTH   AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

established  because  the  mating  season  is  then  nearly  over.  May,  then, 
is  the  climax,  or  peak  month,  of  the  breeding  season,  and  rainfall 
then  is  of  greater  significance  than  at  any  other  period. 

The  nature  of  rains  in  May  may  be  a  factor  modifying  the  use  of 
precipitation  records  for  that  month  as  indices  of  the  number  of 
chicks  produced,  as  short,  heavy  downpours  may  be  more  serious  than 
slow  steady  rains.  This,  however,  is  not  known  to  be  true.  Fre- 
quently recurring  light  rains  may  be  as  serious  as  heavy  ones  be- 
cause persistent  damp  conditions  result  in  heavy  juvenile  mortality 
from  chilling.  Stoddard  (1931:  39,  202)  shows  that  wet  spring 
months  are  favorable  for  hatching  but  not  for  rearing  bobwhites. 
Percolation  and  drainage  are  slow  in  the  heavy  coastal  prairie  soil, 
and  surface  moisture  accumulates  from  persistent  light  rains  as  surely 
as  from  brief  heavy  ones ;  the  amount  rather  than  the  severity  of  the 
rain  seems  to  rule. 

While  it  is  realized  that  annual  precipitation,  drainage,  cover,  and 
other  environmental  conditions  in  Colorado  County  are  not  identical 
with  those  obtaining  throughout  the  coastal  prairie  chicken  country, 
a  marked  similarity  does,  nevertheless,  exist.  Rainfall  is  moderately 
heavy,  39  inches  annually,  at  Columbus,  Colorado  County,  and  it  is 
also  generous  throughout  the  bird's  range.  Average  annual  precipi- 
tation varies  from  49.35  inches  at  Beaumont,  Jefferson  County,  to 
33.69  inches  at  Austwell,  Refugio  County,  at  about  the  eastern  and 
western  limits,  respectively,  of  the  subspecies.  Rainfall  during  May 
at  Columbus  (average,  4.38  inches)  is  heavier  than  in  any  other 
month.  May  is  the  wettest  month  in  Jackson,  Goliad,  Lavaca,  and 
Harris  Counties  as  well.  Heavy  or  persistent  rains  transform  tre- 
mendous areas  in  Colorado  County  into  veritable  lakes  ranging  from 
a  few  inches  to  several  feet  in  depth;  rains  produce  similar  results 
throughout  the  coastal  region.  It  appears  justifiable,  therefore,  to 
assume  that  rainfall  in  May  is  the  key  to  prairie  chicken  reproduc- 
tion throughout  coastal  Texas  (fig.  3). 

Of  every  5  years  in  a  given  locality,  apparently  2  are  favorable 
for  nesting,  2  fair  to  poor,  and  1  bad,  as  determined  by  rainfall  in 
May.  Conditions  are  never  uniform  in  the  chicken  country  a^  a 
whole  because  there  is  variation  between  counties  and  even  between 
parts  of  the  same  county.  Records  of  the  Weather  Bureau  for  May 
1935  show,  for  example,  that  rainfall  at  Galveston,  Galveston  County, 
was  favorable  (2.71  inches  below  average) ;  at  Houston,  Harris 
County,  fair  (only  0.20  inch  below)  ;  and  that  at  Columbus,  Colorado 
County,  poor,  being  approximately  twice  average  (4.83  inches  above). 
During  1926  in  Brazoria  County  conditions  were  good  at  Alvin,  fair 
at  Angleton  and  Freeport,  and  poor  at  Brazoria.  In  1932  conditions 
were  good  at  Angleton,  fair  at  Freeport,  and  poor  at  Alvin.  Though 
man  cannot  regulate  rainfall  to  promote  prairie  chicken  welfare 


North  American  Fauna  57,  FUh  and  Wildlife  Service 


LEGEND 

Rainfall  1.50  inches  or  more  below  average f^— )  (Good) 

Rainfall  1.49  below  average  to  1 .99  above  average fTTT]  (Fair) 

Rainfall  2  inches  or  more  above  average,  but  less  than  twice  average MlIlX  (Poor) 

Rainfall  twice  average  or  more ^^B  (Bad) 

Compilations  based  on  records  of  average  annual  May  rainfall  at  each  individual  station  as 

supplied  by  the  Climatological  Division.  U.  S.  Weather  Bureau. 
Records  missing  or  unsatisfactory ^ |  O    ) 


Rainfall  conditions  in  May  in  the  range  of  Attwater's  prairie  chicken  in  Texas,  in  the  66  years  1871  to  1936. 
indicating  the  probable  frequency  of  good  and  other  reproductive  years  for  the  birds 


ATTWATER'S   PRAIRIE    CHICKEN  35 

at  nesting  and  brooding  time,  in  many  caseg  he  can  regulate  pasture 
burning  and  grazing  to  provide  adequate  nesting  cover  in  the  best- 
drained  parts  of  the  land.  Also,  he  can  consult  weather  records 
before  setting  open  seasons  and  bag  limits,  which  should  not  be 
uniformly  applied  but  adjusted  to  local  conditions  to  preserve  the 
birds. 

Floods 

Flood  conditions  are  often  produced  by  heavy  rains  in  the  over- 
grazed and  overf armed  sections  in  the  upper  part  of  the  State. 
Heavily  burdened  streams  carrying  flood  crests  from  the  upper  coun- 
try sometimes  spill  over  their  low  banks  and  spread  their  silt-laden 
waters  over  thousands  of  acres  of  prairie  chicken  range.  This  oc- 
curred in  the  Rock  Island-Garwood  section  (Colorado  County)  in 
June  1936,  when  the  prairie  chicken  population  of  that  section  was 
extirpated.  Floods  evidently  are  a  constant  menace  to  birds  near 
major  streams. 

Dbought 

Extreme  drought  seriously  affects  prairie  chickens,  especially  dur- 
ing the  hot  summer  months.  G.  P.  Ferguson,  State  game  warden, 
and  fence  riders  on  the  M.  O'Conner  ranch,  Refugio  County,  found 
many  dead  birds  in  the  especially  dry  summer  of  1917  and  saw  others 
too  weak  to  fly.  Drought  reduces  food  supplies  for  both  present  and 
future  use.  Large  cracks  that  form  in  black  soil  in  dry  weather  pos- 
sibly trap  some  young  birds,  according  to  the  observations  of  Gross 
(Bent  1932:  253).  Birds  weakened  by  excessive  heat,  and  possibly 
also  by  a  shortage  of  food,  are  especially  vulnerable  to  disease,  pred- 
ators, adverse  weather,  and  other  hazards. 

HUBBICANES 

Tropical  hurricanes  sometimes  produce  flood  conditions  in  prairie 
chicken  country  20  miles  or  more  from  the  Gulf.  In  1917  a  storm 
backed  salt  water  over  the  greater  part  of  the  Pipkin  ranch  in  the 
Big  Hill  area  in  Jefferson  County  and  drowned  livestock  by  the 
hundreds.  That  it  evidently  destroyed  many  prairie  chickens  as 
well  was  indicated  by  their  exceeding  scarcity  for  15  years  afterwards. 

Hatt. 

Heavy  hail  storms  destroy  many  Attwater's  prairie  chickens,  es- 
pecially in  areas  where  heavy  protective  cover  is  lacking.  After  a 
storm  in  May  1934,  J.  O.  Linney,  Guy  Ferguson,  and  fence  riders  on 
the  Salt  Creek  ranch,  Refugio  County,  saw  about  150  dead  or  crippled 
chickens. 


36       NORTH  AMERICAN  FAUNA   5  7,  FISH  AND  WILDLIFE  SERVICE 

Local  Stobms 

Local  storms,  especially  those  that  commonly  occur  in  fall,  kill 
turkeys  and  other  domestic  fowls  and  prairie  chickens  and  other  game 
birds,  as  reported  by  Marcus  Shindler,  Ed  Koy,  and  other  resident 
land-owners  in  the  northeastern  part  of  Colorado  County. 

Disease 

Gross  (1930a:  39),  and  Stoddard,  Curtis,  Lews,  Terrel,  and  others 
(Leopold  1931:  182-183),  recorded  incidents  strongly  suggesting  that 
disease  and  parasites  probably  were  important  controlling  factors  on 
the  abundance  of  the  greater  prairie  chicken  of  the  Northern  States. 
Records  at  hand  do  not  show  that,  in  the  past,  disease  has  been  a  factor 
of  importance  limiting  the  numbers  of  Attwater's  prairie  chicken  in 
Texas.  The  observations,  mentioned  above,  made  by  G.  P.  Ferguson 
on  the  M.  O'Conner  ranch  furnished  the  only  known  evidence  even 
faintly  suggesting  an  outbreak  of  disease.  In  that  instance,  however, 
it  is  probable  that  mortality,  if  really  due  to  disease  or  parasites,  was 
an  indirect  result  of  prolonged  drought.  No  evidence  of  disease  or 
heavy  parasitism  was  found  in  autopsies  made  on  13  prairie  chickens, 
and  no  evidence  of  any  unhealthful  condition  was  observed  among 
hundreds  of  birds  in  the  field.  Prairie  chickens  are  doubtless  sus- 
ceptible, however,  to  ailments  of  domestic  poultry.  An  outbreak  of 
blackhead  disease,  probably  contracted  from  domestic  turkeys,  is  con- 
sidered by  Gross  (Bent  1932:  268)  as  a  major  factor  in  the  extermina- 
tion of  the  heath-hen.  Turkeys  and  other  poultry,  therefore,  probably 
are  unhealthful  influences  on  a  prairie  chicken  range. 

Speead  of  V^oody  Vegetation 

The  encroachment  of  mesquite,  live  oak,  various  acacias,  and  other 
kinds  of  brush  onto  open  prairie  land  has  been  an  extremely  impor- 
tant factor  in  reducing  the  range  and  doubtless  the  numbers  of  Att- 
water's prairie  chickens  in  Refugio  and  other  counties  to  the  south 
and  west.  Within  the  memory  of  living  men  extensive  prairies  have 
been  transformed  into  brush  jungles.  Specific  factors  that  have  in- 
fluenced the  rapid  vegetational  changes  in  the  southwestern  brush 
country  are  imperfectly  understood.  Factors  probably  of  importance 
in  enabling  woody  plants  to  replace  the  native  grassland  flora  have 
been  overgrazing,  especially  during  drought  j^ears;  the  mechanical 
planting  of  tree  seeds  by  cattle  and  horses,  because  livestock  eat  large 
quantities  of  mesquite  and  other  beans,  the  seeds  of  which  pass  through 
the  digestive  tract  and  are  distributed  or  planted  by  the  droppings; 
the  elimination  of  burning,  previously  mentioned  by  Bray  (1901: 
288-290)  and  Tharp  (1926:  71)  ;  and  the  lowering  of  the  water  table. 
Be  that  as  it  may,  hundreds  of  thousands  of  acres  of  what  was  once 


ATTWATERS    PRAIRIE    CHICKEN 


37 


tall-grass  prairie  are  now  brushlaiid,  and  prairie  chickens  are  gone 
from  these  areas. 

Pkedation 


Natural  enemies  consume  some  of  the  eggs,  young,  and  adults  of 
Attwater's  prairie  chicken.  The  extent  of  predation  on  nests  and  the 
identity  of  other  factors  responsible  for  nest  loss  in  the  Eagle  Lake 
area  are  eiven  in  tables  12  and  13. 


Table  12. — Fate  of  nests,  Eagle  Lake,  Colorado,  1937 


Nest 
No. 

Pasture 

Date 
found 

Date 
destroyed 

or 
hatched 

Probable  cause  of  destruction 

1 

Everett 

Apr.     7 

Apr.     8 
Apr.   12 
__..do.... 
Apr.   13 
Apr.  21 
____do..__ 
_...do.-_. 
Apr.  27 
Apr.  29 
May    1 

May  11 
June    1 

Apr.  22 

Apr.    4  3 
Apr.     7 
Apr.   13 
May  17 
Apr.   15 
Apr.  21 
Apr.   18 
May    4 
May  15 
May    2 

Apr.     6 
June    2 

or 
June    3 

21 

3  1 

do 

Wintermann_  

by  a  farmer. 
Red  wolf— female  bird  killed  on  nest. 

4.. 

5 

do 

Sklar-M  arcella 

Wiutermann 

Skunk. 

Hatched  successfully. 

61    

Skunk. 

7  1 

81 

9        

do 

do 

Duncan 

Do. 
Deserted,  cause  unknown. 
Hatched  successfully. 

10 

Everett  . 

Do. 

11 

Willis 

Man — nest  deserted  after  farmer  plowed  territory 

nearby  and  revisited  nest  frequently. 
Opossum. 

12  2 

13 

Sklar-Marcella 

...  do 

1  Nest  destroyed  when  found. 

'  Estimated  in  case  of  nests  destroyed  when  found. 

>  Indicated  by  circumstantial  evidence  at  the  nest. 

Table  13. — Fate  of  nests.  Eagle  Lake,  Colorado  County,  Tex.  (1938) 


Nest  No. 

Pasture 

Date 
found 

Date  de- 
stroyed 

or 
hatched 

May    3 
Apr.  23 
Apr.  29 
May    3 
May  11 
June  21 

Probable  cause  of 
destruction  i 

14        

Sen 

Apr.  13 
Apr.  18 
..  do     .. 

Heavy  rain. 

15 

Thomas .  . 

House  cat. 

16 

do 

Hatched  successfully. 

17 

...    do 

Apr.  29 
Apr.  20 
June    3 

Heavy  rain. 

18 

Everett    

Opossum. 

19 

.  do 

Hatched  successfully. 

I  Indicated  by  circumstantial  evidence  at  nest. 

Of  19  prairie  chicken  nests  studied  in  1937  and  1938,  6  (31.5 
percent)  were  successful,  and  13  (68.4  percent)  were  lost.  In  1937 
8  of  13  nests  studied  were  destroyed  before  the  clutches  were  com- 
plete, showing  that  the  laying  period  may  be  the  one  of  heaviest 
nest  loss.  This  might  be  expected,  as  the  eggs  are  covered  only  about 
an  hour  or  so  each  day  during  that  time.  This  loss  is  somewhat 
compensated,  however,  by  renesting  (see  p.  15).  Opossums  and 
skunks  destroyed  6  nests — more  than  any  other  agency.     Of  the  6, 


38       NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

however,  4  were  in  a  pasture  where  unregulated  fire  had  restricted 
good  nesting  cover  to  2  small  unburned  areas  about  3  and  10  acres 
in  size.  Fur  animals  as  well  as  nesting  chickens  were  unnaturally 
concentrated  in  these  unburned  plots;  dens  containing  young  were 
100  yards  or  less  from  each  of  the  nests  destroyed.  Excessive  pas- 
ture burning  appeared  to  be  the  primary  cause  of  the  heavy  nest 
loss ;  predation  by  fur  animals  being  merely  an  effect,  the  agency  of 
destruction  that  was  inevitable  after  the  burning. 

Field  evidence  showed  that  a  red  wolf  killed  a  female  prairie 
chicken  and  destroyed  her  nest;  a  feral  house  cat  devoured  the 
eggs  from  another  nest  (pi.  10).  It  is  surprising  that  dogs  did 
not  figure  as  predators  on  the  nests  and  that  house  cats  did  not 
take  an  even  greater  number.  Wandering  dogs,  usually  in  groups  of 
three  to  five,  were  not  imcommon  on  Colorado  County  prairies;  L. 
A.  Burchfield,  a  trapper  who  worked  for  the  former  Bureau  of 
Biological  Survey  in  Colorado  County  in  1937,  and  Waddell  found 
that  dogs  did  much  of  the  damage  for  which  the  few  red  wolves, 
now  largely  extirpated  in  the  area,  were  blamed.  Heavy  predation 
on  a  flock  of  domestic  turkeys,  supposedly  by  wolves,  stopped  imme- 
diately when  a  hound,  which  frequently  hunted  on  its  own  initiative, 
was  killed  after  having  been  caught  in  a  trap  set  for  the  alleged 
wolves.  Feral  house  cats  on  Colorado  County  prairies  probably 
outnumber  skunks,  opossums,  minks,  or  any  other  fur  animals.  Cot- 
ton rats  and  other  rodents  were  common  near  several  nests  but  took 
no  eggs.  Neither  did  racers,  chicken  snakes,  king  snakes,  or  other 
reptiles  frequently  noted  after  May  1  in  both  1937  and  1938. 

Three  nests  were  abandoned,  desertion  of  two  of  these,  possibly 
all  three,  being  caused  by  man.  Nesting*  prairie  chickens  seem 
especially  sensitive  to  interference,  and  they  should  not  be  dis- 
turbed by  persons  making  repeated  visits.  Of  six  nests  under  obser- 
vation in  1938,  floods  destroyed  two,  and  accumulated  water  from 
heavy  rains  came  within  ly^  feet  of  a  third  (nest  16).  The  following 
excerpt  from  the  writer's  field  notes  of  May  3,  1938,  emphasizes  the 
importance  of  floods : 

The  prairie  has  been  transformed  into  a  miniature  ocean  clotted  by  tiny 
islands  that  previously  had  been  the  tops  of  knolls  and  ridges.  On  these 
islands  sit  wet  and  bedraggled  prairie  chickens  and  other  birds  that  seem  as 
confused  and  astounded  as  I  by  the  sudden  change  in  their  environment.  About 
a  5-inch  depth  of  vrater  covers  the  sites  of  nests  14  and  17,  and  former 
nest  15.  Nest  16  has  escaped  by  a  hair's  breadth,  but  the  lining  is  very  soggy. 
Problems  due  to  hawks,  skunks,  and  other  predators  seem  so  petty  v^^hen  exces- 
sive rain  destroys  virtually  everything  at  a  single  stroke. 

YOUNG 

Although  predators  doubtless  exert  great  pressure  on  the  popula- 
tion of  young  prairie  chickens  in  some  areas,  especially  because  the 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


Plate  10 


ICV 


■■"4ili 


Above,  Shells  of  eggs  at  prairie  chiclcen  nest  destroyed  by  house  cat;  Colorado 
County,  Tex.,  approximately  5  miles  north  of  Eagle  Lake,  April  23,  1938. 
(Photo  by  Texas  Game,  Fish,  and  Oyster  Commission;  E.  P.  Haddon.)  Below, 
Freshly  killed  prairie  chicken  recovered  from  a  ferruginous  rough-legged  hawk; 
Colorado  County,  Tex.,  approximately  6  miles  north  of  Eagle  Lake,  April  7, 
1937.      (Photo  by  V.  W.  Lehmann.) 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE    1  1 


B49777A;   E60058 

Above,  Xative  bluestem  prairie— well  populated  b.y  prairie  chickens:  Colorado 
County,  Tex.,  6  miles  northeast  of  Eagle  Lake,  December  21,  1936.  Below, 
Prairie  after  plowing  for  rice — deserted  by  prairie  chickens;  Colorado  County, 
Tex.,  ajjproximately  5  miles  north  of  Eagle  Lake,  March  7,  1938.  (Photos 
by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN  39 

loose  formation  of  the  brood  (see  p.  19)  and  straying  apparently 
induce  mortality  from  this  cause,  definite  information  was  difficult 
to  obtain. 

A  female  Krider's  hawk  caught  a  third-grown  prairie  chicken  on 
May  24,  1937.  From  then  on  until  June  9,  when  the  male  was  col- 
lected, this  hawk,  assisted  by  her  mate,  hunted  a  section  containing 
six  broods.  Most  migrant  raptors  (roughlegs,  redtails,  and  marsh 
and  duck  hawks)  had  left  Colorado  County  prior  to  May  1,  1937,  and 
April  15,  1938,  before  many  young  had  hatched,  and  the  resident 
species  (red-shouldered.  Cooper's,  Sennett's  white-tailed,  and  Krider's 
hawks)  confined  their  activities  largely  to  wooded  areas.  Because 
cover  is  dense  in  summer,  and  hawks  are  then  uncommon,  probably 
few  young  prairie  chickens  are  taken  in  normal  years. 

House  cats  with  freshly  killed  young  prairie  chickens  were  noted 
twice  in  1937  and  were  seen  stalking  broods  on  three  other  occasions. 
Because  of  their  numbers  and  predilections,  house  cats  are  thought 
to  be  exceedingly  destructive. 

ADULTS 

Prairie  chickens  on  the  courtship  grounds  seemed  more  intent 
on  mating  than  on  self-preservation ;  consequently,  losses  from  preda- 
tion  were  probably  heaviest  at  mating  time.  In  Colorado  County, 
during  most  of  the  1937  and  1938  courtship  seasons  the  abundant 
hawks  harassed  the  prairie  chickens  persistently,  sometimes  with 
success.  On  April  8,  1937,  3  duck  hawks,  7  marsh  hawks,  2  rough- 
legs,  3  Krider's  hawks,  and  2  bald  eagles  kept  the  chicken  population 
(about  45  birds)  of  the  Everett  pasture  (640  acres)  constantly  mov- 
ing. A  freshly  killed  male  prairie  chicken  (pi.  10)  was  taken  from 
a  ferruginous  roughleg  in  that  area  on  April  17.  Marsh  hawks, 
which  Stoddard  and  others  have  found  to  be  sometimes  more  bene- 
ficial than  harmful  to  quail  and  other  game,  were  especially  an- 
noying to  courting  birds,  no  other  factor  interfering  with  their 
activities  to  so  great  an  extent.  Wlien  a  marsh  hawk  darted  at 
one  occupant  of  the  booming  ground,  others  generally  cowered.  The 
hawks  pursued  their  intended  victims  for  short  distances,  but  soon 
returned  and  flushed  others,  or  after  dispersing  the  grouse,  fre- 
quently alighted  on  the  courtship  grounds  to  await  their  return  and 
resume  the  flushing  tactics.  On  April  8,  1937,  4  marsh  hawks  con- 
centrated on  a  single  courtship  ground  and  harassed  the  6  male 
occupants  from  5  to  7 :30  p.  m.  Although  no  birds  were  killed,  one 
lost  many  feathers  when  two  hawks  dived  at  it  simultaneously. 

By  flushing  prairie  chickens,  marsh  hawks  render  them  vulnerable 
to  more  efficient  winged  enemies,  as  duck  hawks,  goshawks,  and  the 
like.  Waddell  has  seen  duck  hawks  catch  adult  chickens  on  at 
least  two  occasions. 


40       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

Mammals  also  take  some  of  the  birds  on  courtship  areas.  The 
stomach  of  a  male  house  cat  collected  April  12,  1937,  near  a  booming 
ground  in  the  Everett  pasture,  Colorado  County,  contained  the  head, 
feet,  and  part  of  the  breast  of  a  freshly  killed  male  prairie  chicken. 
The  remainder  was  found  about  50  feet  away. 

A  red  wolf  was  suspected  of  killing  a  female  prairie  chicken  on 
the  nest,  and  either  red  wolves  or  dogs  took  three  others  in  Colorado 
County  in  April  1937. 

Only  six  instances  of  adult  mortality  were  discovered  that  year, 
although  intensive  search  for  remains  was  made  on  foot  and  in  cars 
over  approximately  2,500  acres.  In  1938,  when  none  of  the  pastures 
were  burned,  no  dead  birds  were  found. 

Review  of  Natueai.  Factors 

Natural  factors  limit  the  abundance  of  prairie  chickens  by  destroying 
eggs,  young,  and  adults  and  by  reducing  favorable  territory.  During 
the  breeding  season  floods,  storms,  hail,  drought,  and  excessive  or  per- 
sistent rains  are  known  to  be  locally  serious,  the  rains  in  May  being  most 
damaging.  Drought  has  been  associated  with  the  only  reported  out- 
break of  disease  that  occurred  in  the  Refugio  area  in  1917.  The  en- 
croachment of  brush  on  prairie  land  has  transformed  thousands  of  acres 
of  what  was  once  good  prairie  chicken  range  (pi.  11)  into  an  unfavorable 
habitat.  Although  some  predators  harass  the  birds  throughout  the 
year,  their  effects  are  probably  most  serious  at  mating  and  nesting 
time.  Natural  mortality  from  climate  and  predators  is  severe  in 
inferior  or  isolated  cover. 

The  serious  effects  of  natural  factors  are  in  every  case  either  brought 
about  or  intensified  by  man's  generally  unwise  treatment  of  natural 
factors.  All  except  feral  house  cats  and  predatory  dogs  were  operat- 
ing against  the  prairie  chickens,  apparently  without  disastrous  results, 
before  the  environment  was  radically  modified  by  man.  Since  the 
unfavorable  influences  of  natural  agencies  are  due  chiefly  to  man,  it 
is  encouraging  to  know  that  it  is  within  his  power  and  often  decidedly 
advantageous  to  him  so  to  modify  his  actions  as  to  improve  existing 
conditions  and  promote  the  welfare  of  the  prairie  chickens  as  well  as 
his  own. 

ARTIFICIAL  FACTORS 

Agrictjlttiee 

Much  of  the  best  prairie  chicken  range  has  been  recently  appro- 
priated for  agricultural  uses.  More  than  2,000,000  acres  (table  14) 
were  cultivated  in  1936.  In  addition,  thousands  of  acres  of  sod  are 
plowed  annually,  with  the  extension  of  agriculture,  especially  rice 
farming.     The  acreage  yearly  planted  to  rice  in  coastal  Texas  in- 


ATTWATER'S   PRAIRIE    CHICKEN 


41 


creased  from  approximately  174,500  acres  in  1922  to  more  than  196,500 
acres  in  1937.^  This  latter  acreage  represents  only  a  small  part  of  the 
area  actually  depleted:  rice  farming  has  ruined  more  than  84,000 
acres  for  the  birds  in  Colorado  County  (pi.  11)  alone,  and  probably 
in  excess  of  a  million  acres  in  the  State  as  a  whole.  Rice  is  hard  on 
the  land  and  most  areas  devoted  to  it  can  be  profitably  cultivated 
during  only  about  1  year  in  4,  after  which  they  must  be  left  fallow  for 
about  3  years  to  "sweeten."  Weedy  rice  fields  ostensibly  provide  satis- 
factory grouse  range ;  actually,  however,  they  lack  suitable  courtship 
grounds  and  safe  nesting  cover,  and,  furthermore,  the  levees  collect 
water  that  floods  nests.  Prairie  chickens  in  fallow  rice  land  ap- 
parently are  doomed  even  though  they  are  hunted  lightly  or  not  at 
all.  According  to  Waddell,  there  were  10,000  of  the  birds  on  30,000 
acres  of  the  Egypt  section,  Wharton  Comity,  in  1924.  Rice  farming 
began  there  in  1925,  and  by  1937  all  the  30,000  acres  were  either  in 
cultivation  or  fallow.  Hunting  pressure  was  reduced  annually  after 
1925,  and  few,  if  any,  birds  were  killed  after  1935.  In  1938,  however, 
less  than  150  prairie  chickens  remained.  Prairie  chicken  decrease  was 
also  positively  correlated  with  the  expansion  of  rice  farming  in  eastern 
Chambers  and  central  Matagorda  Counties.  As  additional  acres  of 
prairie  are  plowed,  further  decreases  are  certain  to  follow. 


Table  14. — Harvested  and  other  crop  land  (1936)  in  counties  partially  or  en- 
tirely within  the  probable  former  range  of  Attwater's  prairie  chicken  in 
Texas  ^ 


County 

Harvested 
crop  land 

Other 
crop  land 

Total 
crop  land 

County 

Harvested 
crop  land 

other 
crop  land 

Total 
crop  land 

Aransas 

Acres 

2,484 
105,  396 

92,  247 
98,045 
34,  425 

130,  684 
16,  772 

93,  562 
153,  307 
176,  495 

19,  848 
64,  374 
100,  263 
82,  609 
44,205 

Acres 
1,772 
11,313 
20,  685 
17,  787 
12,  580 
32,  483 
5,727 
11,038 
30, 843 
41,  793 
3,396 
12,  711 
25,  031 
15, 114 
12, 386 

Acres 

4,  256 
116,  709 
112,  932 
115, 832 
47, 005 
163, 167 
22,  499 
104,  600 
184, 150 
218,  288 
23,244 
77, 085 
125,  294 
97,723 
56,  591 

Kenedy . 

Acres 

204 

28,  639 

158,  604 

47,704 

59,  714 
228,  609 

8,245 
40, 147 
165,  691 
100,  300 
47,  986 
187,  555 

60,  981 

Acres 

Acres 
204 

7,211 
10,  652 
12,  836 

21,  952 
62, 090 

1,334 
16, 183 
35,  769 
17,828 
10, 040 

22,  909 
10, 001 

35  850 

Bee                 

Lavaca 

169  256 

Brazoria    

Liberty       

60  540 

Matagorda. - 

Nueces 

81  666 

Cameron        -  - 

290,  699 
9  579 

Chambers    

Orange              

Refugio    

56,  330 
201  460 

DeWitt           -  - 

San  Patricio 

Victoria       

Fort  Bend 

118,  ]  28 

Galveston 

58,  026 

Goliad  - 

Wharton 

Willacy    

210,  464 
70,  982 

Total 

2,349,095 

483,464 

2, 832, 559 

1  Data  from  Texas  Almanac  and  State  Industrial  Guide,  pp.  231-236,  The  Dallas  News,  1936. 

Pasture  Burning 

Unregulated  prairie  fires  intentionally  set  or  of  accidental  origin 
have  been,  and  still  are,  common  in  coastal  Texas  in  every  month  of 


•^  Figures  supplied  by  David  Wintermann,  Relow  Land  Company,  Eagle  Lake,  Tex.,  from 
data  compiled  by  the  Rice  Milling  Association. 


42       NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

the  year.  In  Colorado  and  Austin  Counties,  for  example,  approxi- 
mately 80  percent  of  the  best  prairie  chicken  country  was  burned  over 
in  1936.  A  fire  of  accidental  inception  ran  over  about  3,000  acres  of 
the  6,700  acre  J.  C.  Anderson  Estate  ranch,  Harris  County,  in  May 
1937.  The  cover  on  about  3,000  acres  of  the  best  prairie  chicken 
country  in  Matagorda  County  was  intentionally  burned  in  July  1937. 
Pasture  burning  is  an  annual  event  on  the  Pipkin  ranch,  Jefferson 
County,  fires  being  started  during  first  new  moon  after  February  15. 
Areas  that  the  first  fires  do  not  cover  cleanly  are  subsequently  treated, 
and  burning  generally  continues  well  through  the  nesting  season. 
Most  ranchmen,  however,  complete  pasture  burning  by  March. 

The  pastures  are  burned  to  remove  old  grass  and  encourage  tender 
new  growth  more  palatable  to  livestock.  Fires  usually  are  set  when 
the  grass  is  dry  and  the  wind  brisk,  in  order  to  finish  the  job  quickly. 
The  resulting  fast,  hot  fires  entirely  denude  areas  except  in  low  spots 
and  deplete  pastures  of  food,  escape  cover,  and  nesting  sites.  Prairie 
chickens  and  their  natural  enemies  are  crowded  into  unburned  areas 
(pi.  12)  and  predation  is  undoubtedly  intensified.  During  the  breed- 
ing season  fires  destroy  nests  and  probably  many  young  birds  as  well ; 
no  fewer  than  nine  nests  with  charred  eggs  were  found  by  Waddell  in 
a  640-acre  pasture  burned  in  May  1936.  Plant  life  recovers  slowly 
in  the  absence  of  abundant  rain;  consequently,  fires  accentuate  the 
results  of  drought.  Altogether,  fire  is  one  of  the  most  important 
factors  limiting  prairie  chicken  numbers  in  pastures.  When  burning 
is  carried  on  as  outlined  under  Management  (pp.  53  to  54),  however, 
the  evils  are  greatly  reduced  or  entirely  eliminated,  and  benefits 
accrue  to  forage  and  soil  as  well. 

OVEKQRAZINO 

With  the  possible  exception  of  Orange  and  Jefferson  Counties,  over- 
grazing is  severe  in  most  of  coastal  Texas  from  late  in  fall  through 
early  spring.  In  addition  to  reducing  cover  and  food  for  prairie 
chickens  (pi.  12),  overgrazing  probably  also  increases  the  vulnera- 
bility of  the  birds  both  to  natural  enemies  and  to  man.  In  Colorado 
County  from  1936  through  1938,  for  example,  it  was  noted  that  marsh 
hawks  and  other  raptors  harried  chickens  more  persistently  in  lightly 
vegetated  pastures  than  in  areas  where  heavy  grassy  cover  was  pres- 
ent. Waddell  observed  that  hunters  regularly  kill  a  higher  percent- 
age of  known  populations  in  areas  where  cover  is  light  than  where  it 
is  heavy.  In  Colorado  County  it  has  been  found  that  the  winter 
prairie  chicken  population  of  a  pasture  can  be  forecast  with  consider- 
able accuracy  by  observing  the  extent  to  which  the  area  is  grazed. 
Large  winter  populations  are  rare  in  pastures  where  cover  is  short. 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


PLATE    12 


B49778:   B60059 


Above,  Excellent  unburned  cover  at  right  of  road;  inferior  burned  cover  at  left; 
Colorado  County,  Tex.,  approximately  7  miles  north  of  Eagle  Lake,  December 
22,  1936.  Below,  Scanty  cover  where  there  has  been  overgrazing;  the  shrub  is 
Cherokee  rose  (Rosa  laevigata);  Colorado  County,  Tex.,  6  miles  north  of  Eagle 
Lake,  March  7,  1938.      (Photos  by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN  43 

Aside  from  resulting  unfavorably  to  prairie  chickens,  overgrazing 
in  the  gulf  coastal  country  has  been  and  is  resulting  in  (1)  the  spread 
of  undesirable  brush  and  weeds,  (2)  the  increase  of  needlegrass  and 
other  largely  unpalatable  grasses,  and  (3)  serious  erosion.  An  abun- 
dance of  prairie  chickens  cannot  be  maintained  on  overgrazed  tracts ; 
it  is  equally  impossible  to  maintain  forage  and  soil  on  such  areas. 

Orti  Deveix)pment 

Oil  development,  which  began  with  the  discovery  of  the  Spindle 
Top  field  in  Jefferson  County  in  1901,  has  extended  to  every  county 
in  the  coastal  section.  All  the  Attwater's  prairie  chicken  area  is 
classed  as  potential  oil  land,  and  almost  every  acre  has  been  surveyed 
not  once,  but  several  times  by  oil  crews.  Veritable  forests  of  oil  der- 
ricks now  stand  in  areas  that  once  provided  some  of  the  finest  prairie 
chicken  range.  In  these  areas,  as  in  Fort  Bend  County,  prairie 
chickens  are  almost,  if  not  completely  gone. 

Drainage 

Drainage  canals,  as  in  Brazoria  and  certain  other  coastal  counties, 
have  in  some  instances  improved  the  territoiy  within  a  mile  or  so  of 
their  margins  by  providing  a  permanent  water  supply  where  it  was 
otherwise  lacking  during  the  summer  months.  On  the  other  hand, 
drainage  canals  have  doubtless  decreased  the  general  wildlife  pro- 
ductivity of  the  counties  in  which  they  are  situated  by  speeding  up 
the  run-off  and  thus  lowering  the  water  table.  Until  recently  many 
prairie  ponds  retained  water  throughout  the  year,  produced  crappie, 
bream,  and  other  edible  fish,  held  safe  nesting  cover  for  black 
mallards  and  other  water  birds,  grew  an  abundant  supply  of  food  for 
wintering  waterfowl,  and  served  as  concentration  points  for  prairie 
chickens  during  the  heat  of  summer.  Now  they  go  dry  during  the 
slightest  drought  and  produce  virtually  nothing. 

Pastube  Mowing 

Regular  mowing  of  grassy  areas,  mainly  for  hay  or  increased 
forage  production,  has  promoted  a  nearly  pure  stand  of  grass  in  some 
of  the  areas  treated  and  has  reduced  shade  and  food,  and  the  general 
attractiveness  of  the  areas  for  prairie  chickens  and  certain  other 
valuable  wildlife.  In  Colorado  County,  areas  that  have  been  mowed 
regularly  for  long  periods  are  virtually  game  deserts ;  prairie  chickens 
use  them  little  even  at  nesting  time.  Pasture  mowing  in  coastal 
Texas  appears  to  be  extending  rapidly,  and  further  reduction  in 
wildlife  resources  may  be  expected  from  this  cause  unless  definite 

303807°— 41 4 


44       NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

modifications  are  effected.  Fortunately,  the  detrimental  effects  of 
pasture  mowing  to  upland  game  birds  may  be  mitigated,  at  least  to 
some  extent,  by  following  management  recommendations  listed  on 
page  56. 

Mechanical  Accidents 

Prairie  chickens  sometimes  fly  into  telephone  wires,  fences,  and 
houses,  or  are  struck  by  automobiles.  In  six  instances  in  1937  birds 
were  noted  as  accidentally  killed  in  the  Eagle  Lake  section — as  many 
as  were  recorded  for  predation.  Mortality  from  accidents  may  be 
far  more  serious  than  is  generally  appreciated. 

Hunting 

Last,  but  not  least,  hunters  certainly  have  contributed  to  prairie 
chicken  decrease.  Hunting  has  never  been  well  regulated,  and  laws 
governing  the  taking  of  the  birds  have  always  been  inadequate.  Ac- 
cording to  the  Texas  Game,  Fish,  and  Oyster  Commission  (Ann. 
Kept.,  1929:  86-91)  prairie  chickens  had  no  legal  protection  until 
1883,  when  a  5-month  closed  season  was  declared  during  the  breeding 
period.  In  1885, 148  counties  claimed  partial  or  total  exemption  to  this 
and  other  regulations,  and  it  was  not  until  1903  that  the  legislature 
passed  a  bill  designating  the  months  of  November,  December,  and  Jan- 
uary as  the  open  season  and  setting  a  daily  bag  limit  of  25.  The  legis- 
lation of  1903  was  indeed  a  forward  step,  but  there  was  no  conserva- 
tion body  to  enforce  the  measure,  local  officers  being  depended  on 
to  carry  out  its  provisions.  The  Game,  Fish,  and  Oyster  Commis- 
sion was  not  created  mitil  1910,  and  for  many  years  it  was  without 
adequate  funds  and  personnel.  As  late  as  1919  there  were  only 
6  salaried  wardens  in  Texas  endeavoring  to  carry  out,  as  best  they 
might,  almost  wholly  inadequate  regulations.  The  law  restricting 
the  open  season  on  prairie  chickens  to  4  days,  September  1  to  Sep- 
tember 4,  inclusive,  and  the  bag  limit  to  10  a  day  or  10  a  season, 
was  not  passed  until  1929.  In  1937  there  were  only  9  full-time 
wardens  in  all  the  Attwater's  prairie  chicken  country,  and  they  were 
charged  with  patrolling  more  than  8  million  acres ! 

Development  of  the  coastal  territory,  as  farming,  grazing,  and 
the  exploiting  of  oil,  crowded  prairie  chickens  into  ever  smaller 
areas,  where  they  were  more  easily  found  and  killed.  The  Hug- 
the-Coast  Highway  (State  Highway  No.  35)  and  various  other  roads 
increased  patrol  problems;  the  intercoastal  canal  in  Galveston,  Cham- 
bers, and  Jefferson  Counties  made  formerly  remote  areas  easily 
accessible  to  poachers.  The  number  of  hunters  increased  as  trans- 
portation facilities  and  weapons  were  improved.  The  open  season  in 
September,  normally  a  dry  period  (see  pp.  57  to  58),  did  much  to 


ATTWATER'S   PRAIRIE    CHICKEN  46 

popularize  hunting  from  automobiles.  With  these  and  other  advan- 
tages, hmiters  evidently  harvested  too  closely.  In  the  Bernard  River 
country  (western  Austin  County  and  northeastern  Colorado  County), 
for  example,  it  is  known  that  in  1936  hunters  killed  66  chickens,  or 
22  percent  of  the  estimated  total  population  (300).  This  was  accom- 
plished despite  the  fact  that  the  gunners  were  closely  supervised  and 
did  not  hunt  in  the  most  densely  populated  pastures.  It  is  probable 
that  excessive  kills  have  occurred  in  other  areas  for  many  years; 
the  1937  census  showed  that  Attwater's  prairie  chickens  were  nearly 
or  completely  extirpated  except  on  or  adjoining  lands  where  they  had 
been  hunted  little,  if  at  all,  for  at  least  10  years.  In  Harris,  Galves- 
ton, Waller,  and  possibly  in  parts  of  other  counties,  hunting  has 
probably  been  the  agency  most  largely  responsible  for  prairie  chicken 
decline. 

MANAGEMENT 

Leopold  (1931 :  3)  has  defined  game  management  as  the  art  of 
making  land  produce  annual  crops  of  wild  game  for  recreational  use. 
In  coastal  Texas,  the  management  of  prairie  chickens  must  consist 
largely  of  the  preservation  of  suitable  grassland  areas.  Increased 
protection,  habitat  improvement,  adequate  predator  control,  and 
proper  regulation  of  the  harvest,  however,  will  greatly  encourage 
recovery. 

PROTECTION 

An  act  (H.  B.  30)  passed  by  the  State  legislature,  effective  Sep- 
tember 24,  1937,  forbade  the  killing  of  prairie  chickens  in  Texas  for 
a  period  of  5  years.  This  measure  removes  much  of  the  pressure 
previously  exerted  on  the  birds  during  the  regular  open  hunting  sea- 
son, for  true  sportsmen  will  observe  the  decree.  Landowners,  game 
wardens,  and  other  interested  individuals,  however,  will  remember 
that  close  seasons  may  tend  to  stimulate  rather  than  retard  the  opera- 
tions of  game  bootleggers.  According  to  the  consensus  of  State 
game  wardens  in  the  coastal  territory,  violators  are  especially  active 
(1)  during  the  birds'  spring  courtship  season  when  the  conspicuous 
males,  their  instincts  of  self  preservation  dulled  by  the  the  mating 
urge,  are  easy  targets  for  .22-caliber  rifles;  (2)  late  in  July  and 
August,  when  the  tame  young  birds  are  of  "frying"  size;  and  (3) 
during  the  duck  season,  when  whirring  flocks  of  Attwater's  prairie 
chickens  evidently  tempt  gunners  who  have  insuificient  self  control. 
Coastal  game  wardens  report  that,  in  years  past,  probably  as  many 
prairie  chickens  were  illegally  killed  during  the  duck  season  as  were 
taken  legally  during  the  then  open  season  in  September.  The  restora- 
tion of  the  species  demands  close  protection  for  the  remaining  birds 
at  all  times. 


46       NORTH   AMERICAN   fAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

Altliough.  game  wardens  in  the  prairie  chicken  country  are  sin- 
cere and  energetic,  the  territory  is  too  vast  for  adequate  protection 
under  the  facilities  available.  Sportsmen  may  render  valuable  aid 
by  helping  conservation  officers  apprehend  irresponsible  hunters,  but 
landowners  or  their  resident  agents  must  handle  the  job  if  prairie 
chickens  are  to  receive  anything  like  adequate  protection.  Land- 
owners, individually  or  in  groups,  would  do  well  to  incorporate  their 
holdings  to  form  game-management  areas,  as  advocated  by  the  Ex- 
tension Service,  Texas  Agricultural  and  Mechanical  College  and  the 
Texas,  Game,  Fish,  and  Oyster  Commission.  Under  that  plan,  in- 
creased protection  is  provided  through  appropriate  posting  and 
provision  by  the  landowners  of  qualified,  resident,  free-service  State 
game  wardens.  Also  technical  service  is  given  in  solving  predator 
problems,  improving  wildlife  food  and  cover,  properly  regulating 
harvests,  and  otherwise  maintaining  wildlife  crops.  Nonresident 
owners  should  check  up  on  the  manner  in  which  their  foremen 
or  lessees  protect  wildlife  during  their  absence.  It  is  regrettably 
true  that  some  supposedly  protected  ranches  are  in  reality  hunting 
clubs  for  irresponsible  agents  and  their  friends  when  the  landowners 
are  away.  Long-time  lessees  who  wish  to  manage  prairie  chickens  or 
other  game  should  insist  that  their  contract  include  control  over  the 
wildlife  resources  of  the  property  as  well  as  over  grazing  or  other 
values.  These  lessees  may  thus  avoid  embarrassment  from  unwel- 
come hunter  guests  directed  to  the  area  by  the  absentee  owners. 

Landowners  who  contemplate  leasing  their  holdings  for  oil  develop- 
ment might  well  follow  the  precedent  set  by  a  ranch  owner  in  Refugio 
County.  Each  of  his  contracts  carries  the  provision  that  the  lease 
shall  terminate  immediately  after  any  representative  of  the  contract- 
ing company  is  caught  on  the  property  with  a  gun  of  any  kind. 
Such  a  clause  properly  shifts  the  burden  of  supervising  irresponsible 
oil  workers  from  the  landowner  to  the  oil  company. 

Increased  protection  of  the  few  remaining  Attwater's  prairie 
chickens  is  necessary  for  success  in  management.  Protection  alone, 
however,  is  largely  ineffective  in  areas  where  proper  food  and  cover 
conditions  are  lacking. 

HABITAT  IMPROVEMENT 

At  present  there  are  few  areas  in  Texas  where  excellent  conditions 
for  prairie  chickens  prevail,  and  populations  fluctuate  markedly 
(table  15).  Increase  or  decrease  in  study  areas  was  thought  fre- 
quently to  coincide  with  fluctuations  in  the  supplies  of  food,  cover, 
or  surface  water.  In  many  areas  marked  seasonal  movements  may 
be  averted  and  larger  and  more  stable  populations  maintained  by 
removing  deficiencies  in  habitat. 


ATTWATER'S   PRAIRIE    CHICKEN 


47 


Table  15. 


-Fluctuations  in  numhers  of  prairie  chickens,  Thomas  and  Koy  pas- 
tures, Colorado  County,  1937 


Size 

Prairie  chickens  found 

Pasture 

Feb. 
221 

Apr. 
13 

May 
2 

June 
2, 8, 10 

July 
26 

Sept. 
1 

Oct. 

22 

Nov. 

1 

Thomas     

Acres 
817 
460 

Num- 
ber 
31 
0 

Num- 
ber 
30 
0 

Num- 
ber 
28 
0 

Num- 
ber 
37    16 
14 

Num- 
ber 
0 
23 

Num- 
ber 
17 
32 

Num- 
ber 
0 
0 

Num- 
ber 
1 

Koy                              

0 

>  Count  of  birds  at  or  near  the  courtship  grounds;  no  allowance  made  for  any  birds  that  may  have  been 
missed.    All  other  counts  were  by  the  rope  method.    (See  p.  49.) 

Evaluating  Conditions 

In  some  instances  it  is  relatively  easy  to  point  out  one  or  more  ways 
in  which  areas  are  inferior.  Safe  nesting  cover  is  deficient  in  burned 
pastures  that  are  devoid  of  old  vegetation  except  in  low  damp  places. 
Shade  is  insufficient  on  lands  kept  free  of  tall  weeds  or  shrubs  by 
mowing  or  grazing.  Winter  food,  or  cover,  or  both  are  usually  lack- 
ing in  areas  having  few  native  food-cover  plants,  as  ragweed, 
goatweed  (Croton),  marsh-elder,  or  ruellia.  Sometimes,  however, 
habitat  deficiencies  are  obscure  and  general  observations  of  an  infre- 
quent nature  do  not  identify  them.  Accurate  inventories  are  of 
assistance  in  determining  (1)  whether  habitat  improvement  is  needed, 
(2)  what  should  be  done,  (3)  results  of  work  done,  and  (4)  the  sur- 
plus available  for  hunting.  Management  programs  should  be  formu- 
lated on  the  basis  of  data  obtained  during  inventories  conducted 
thrice  annually,  in  spring,  summer,  and  winter.  Inventory  methods, 
recording  and  interpreting  data,  and  management  practices  are  dis- 
cussed in  the  following  paragraphs. 

Census  Methods 
spring  count  on  the  courtship  gb0und8 

The  first  census  method  that  has  been  tried  and  found  useful  is 
the  spring  count  of  birds  on  the  courtship  grounds.  Necessary  are 
an  automobile,  preferably  of  light  build  and  high  clearance,  a  driver 
who  is  well  acquainted  with  the  area,  and  someone  to  act  as  observer, 
note  keeper,  and  gate  opener. 

A  count  is  made  on  each  courtship  ground  in  the  area,  recording 
the  number  and  sex  of  birds  assembled  there  and  the  number  and 
sex  of  birds  seen  between  these  grounds.  The  number  of  hens  is 
recorded  as  a  supplementary  check.  The  number  of  males,  increased 
80  to  110  percent  to  allow  for  females  that  will  be  missed  is  accepted 
as  the  total  population  of  the  census  area.    For  best  results,  the 


48       NORTH   AMERICAN    FAUNA    5  7,    FISH    AND    WILDLIFE    SERVICE 

spring  count  is  made  in  March  from  daybreak  to  about  7 :  30  a.  m. 
A  population  estimate  based  on  the  maximum  count  obtained  by 
reworking  the  same  area  tliree  successive  mornings,  or  often  enough 
to  offset  variations  due  to  unfavorable  weather,  is  likely  to  be  suffi- 
ciently accurate.  Where  recounts  are  impracticable,  the  single  enu- 
meration should  be  made  on  a  clear,  quiet  morning  after  a  brisk 
norther. 

Courtship  grounds  may  be  located  by  sight  or  sound  of  the  birds 
assembled  there,  but  it  is  preferable  to  "drive  out"  the  census  area  in 
belts  150  yards  or  less  wide.  Drumming  grounds  should  not  be  ap- 
proached more  closely  than  is  necessary,  because  flushing  the  birds 
leads  to  inaccurate  counts.  As  birds  frequently  squat,  or  freeze,  at 
the  approach  of  a  car,  it  is  desirable  to  wait  at  each  occupied  booming 
ground  and  refrain  from  counting  until  after  vigorous  courtship  ac- 
tivity has  been  resumed.  It  is  good  policy  to  encircle  a  counted  area 
completely  before  proceeding  to  a  new  site,  for  the  fresh  car  tracks 
often  assist  in  avoiding  duplication. 

The  accuracy  of  spring  counts  on  the  courtship  grounds  was  tested 
in  the  following  ways:  (1)  A  section  (640  acres)  was  covered  on  10 
successive  mornings;  (2)  a  1,000-acre  pasture  was  searched  with  the 
aid  of  15  bird  dogs;  (3)  a  1,000-acre  pasture  was  recounted  by  5  men 
using  2  cars,  3  horses,  and  2  dogs;  (4)  a  section  worked  3  successive 
days  was  rope  counted.  Spring  counts  have  been  made  over  ap- 
proximately 150,000  acres  in  Colorado,  Wharton,  and  Austin  Counties. 
These  studies  show  that  the  enumeration  of  birds  on  the  courtship 
grounds  is  the  most  rapid  and  economical  of  all  known  census  tech- 
niques. More  than  2,000  acres  a  morning  have  often  been  covered  in 
areas  having  populations  of  about  1  bird  per  45  acres.  There  are  no 
indications  that  the  method  affects  courtship  activities  adversely  or 
that  it  greatly  endangers  early  nesting.  Also,  the  spring  count  of 
males  is  useful  in  yielding  data  on  prairie  chicken  abundance  in  com- 
parable areas  worked  at  nearly  the  same  time  and  under  nearly  the 
same  conditions. 

The  spring  count  of  birds  on  the  courtship  grounds,  however,  is 
not  without  its  defects.  Its  accuracy  is  influenced  by  weather  and 
other  conditions  at  a  time  convenient  for  counting.  Opportunity  is 
limited  to  a  few  hours  a  day  (from  about  6  to  7 :  30  a.  m.)  over  a  short 
period  (in  March).  The  spring  count  does  not  reveal  the  number  of 
females  present,  consequently,  it  does  not  produce  reliable  quantita- 
tive data  on  sex  ratio  and  total  population.  Some  observers  experi- 
ence difficulty  in  distinguishing  males  from  females,  especially  in  the 
poor  light  of  early  morning.  To  them  the  analysis  of  sex  differences, 
presented  on  p.  49,  may  be  helpful. 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE    13 


r»-'  '*»-"i»%   * 


B49329;   B48929 


Above,  Rope  counting  of  prairie  chickens  on  Matagorda  Island,  Tex.,  October  30, 
1937.  Below,  Rope  counting  in  myrtle  brush;  Liberty  County,  Tex.,  approxi- 
mately 8  miles  southeast  of  Devers,  June  27,  1937.     (Photos  by  W.  P.  Taylor.) 


ATTWATER'S   PRAIRIE    CHICKEN 


49 


FIELD    BASIS    FOR    DIFFERENTIATION    OF    THE    SEXES    IN    SPRING 


Males 
General  color Light  gray 

Color  of  breast Not    perceptibly    different 

from  that  of  back. 

Barring    on    back    and     Heavy,  black,  well  defined- . 
breast. 

Color  of  head Orange  -  colored     comblike 

structure  present  above 
each  eye. 

Feathers  of  crest Seldom  erect 

Neck Appears   thick  and  heavy, 

with  large,  brightly  col- 
ored (orange)  air  sac 
apparent  on  each  side  of 
neck  under  prominent 
(2.25  to  2.90  inches)  neck 
tufts. 

Size Large,  heavy  (about  2}^ lb.). 

Action  on  courtship  Bold,  struts,  fights,  and 
grounds.  booms  in  open  cover. 

Flocking Usually  in  groups  of  8  to  12 

when  booming,  feeding, 
or  resting  at  midday. 

Flushing Laborious  take-off;  cackles 

when  rising  from  ground. 


Females 

Brownish  gray. 

Much  lighter  than  that 
of  back;  appears  al- 
most white  in  flight. 

Light,  brownish  black, 
poorly  defined. 

Orange -colored  combs 
absent. 

Frequently  erect. 

Appears  thin  and  long; 
air  sac  and  neck  tufts 
rudimentary  {%a  inch 
long). 


Small,   light    (about   1^ 

lb.). 
Shy,  does  not  strut,  fight, 

or  boom. 
Usually  alone. 


Easy     take-off;     usually 
does  not  cackle. 


THE  ROPE  COUNT 


A  second  method  of  counting,  one  that  has  been  tested  with  most 
encouraging  results  in  the  coastal  prairie  chicken  country,  is  the  rope 
count  (pi.  13).  Essential  equipment  includes  two  automobiles, 
preferably  of  light  build  and  high  clearance,  an  inch  rope  or  a 
quarter-inch  flexible  steel  cable  60  to  120  yards  in  length,  and  two 
strong  swivels.  An  extra  supply  of  water  for  radiators  is  needed 
in  hot  weather  as  cars  heat  up  under  the  heavy  going.  In  addition 
to  drivers  for  the  two  cars,  a  third  person  should  be  taken  along,  if 
possible,  to  act  as  note  keeper  and  general  handy  man. 

When  the  census  area  is  reached,  one  swivel  is  attached  to  the 
right  end  of  the  rear  bumper  of  the  car  in  which  the  note  keeper 
is  to  ride,  and  the  second  swivel  is  attached  to  the  left  end  of  the 
rear  bumper  of  the  other  machine.  Each  end  of  the  rope  or  cable 
is  then  securely  tied  to  a  swivel.  Care  must  be  exercised  to  see  that 
the  rope  or  cable,  in  turning,  will  tighten  its  twist  and  not  loosen  or 
unravel.  One  machine  takes  position  parallel  to  a  fence  or  other 
definite  landmark  while  the  other  goes  far  enough  way  to  stretch  the 
rope  so  that  only  a  slight  bend  remains.  After  both  cars  are  in 
position,  they  drive  over  parallel  courses  at  a  uniform  speed  of  5 


50       NORTH  AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

to  15  miles  an  hour,  which  may  be  increased  in  light  cover  but 
which  should  be  reduced  in  heavy  vegetation  to  keep  the  rope,  for 
the  greater  part  of  its  length,  about  5  inches  above  ground.  Birds 
are  tabulated  as  they  are  flushed.  Those  flying  into  uncovered  ter- 
ritory are  deducted  when  that  area  is  dragged.  Wlien  the  end  of 
a  strip  is  reached,  the  car  in  which  the  note  keeper  rides  turns  and 


ICAftl 


Belt  5.  End  Here - 


*-1 


L 


Belt4. 


Belt  3. 


Bsin. 


t 


Ei         1     1 


Rope^i  ^art  Ksr< -»  ^'"  '• 


FiGUEE  4. — ^Diagram  of  the  rope  count.     Arrows  show  course  of  each  car. 

retraces  its  course  while  the  other  car  makes  a  wide  swing  to  the 
outside  margin  of  another  belt  (fig.  4).  This  is  repeated  until  every 
part  of  the  census  area  has  been  covered. 

The  principle  of  rope  counting  is  not  new.  Askins  (1931:  8)  re- 
ports that  market  hunters  and  others  in  Kansas  "*  *  *  hitched 
a  wire  between  two  wagons  and  with  these  driving  across  the  prairie 
300  yards  apart,  the  gunners  walked  behind  the  wire  taking  the 
grouse  as  they  arose  until  the  wagon  was  filled."    Butchers  of  wild- 


ATTWATER'S   PRAIRIE    CHICKEN  51 

life  (they  have  no  claim  to  the  title  of  sportsmen)  have  used  modi- 
fications of  this  system  in  coastal  Texas  for  years. 

The  rope  census  method  has  been  checked  and  rechecked  for  ac- 
curacy against  the  spring  counts  of  birds  on  the  drumming  grounds, 
car  counts,  and  counts  with  bird  dogs.  The  rope  count,  by  far  the 
most  efficient  of  all,  has  been  tried  over  approximately  45,000  acres 
of  grouse  range,  including  every  major  prairie  type  in  which  Att- 
water's  prairie  chickens  occur  in  Texas.  Heavy  myrtle  brush,  as 
in  Jefferson,  Liberty,  and  other  counties  east  of  the  Brazos  River, 
light  to  heavy  Paspalum-Andropogon  grassland  as  in  Brazoria  and 
Colorado  Counties,  live  oak  shinnery  in  the  northern  part  of  Vic- 
toria County,  rough  weedy  hog  wallow  blackland  of  Refugio  County, 
and  even  the  extremely  rough  salt-grass  area  of  the  same  section, 
have  all  been  negotiated  successfully.  These  tests  have  demonstrated 
clearly  the  practicability  of  the  rope  count  under  all  coastal  prairie 
conditions.  Another  advantage  is  speed;  a  party  can  easily  cover 
2,000  acres  a  day ;  Waddell  and  the  writer  having  counted  the  birds 
on  an  area  of  this  size  in  one  morning. 

Ropes  last  for  a  considerable  period,  one  that  has  been  dragged 
over  20,000  acres  still  being  used.  This  method  of  counting  is  not 
closely  limited  to  a  short  season,  or  to  a  particular  part  of  the  day, 
as  is  the  spring  count  on  the  courtship  grounds.  The  accuracy  of 
the  rope  count  is  not  dependent  on  special  weather  conditions  or  on 
other  variables  over  which  man  has  no  control,  its  major  advantage 
lying  in  the  fact  that,  when  properly  used,  it  gives  an  accurate 
quantitative  count  in  the  census  area.  For  that  reason,  it  is  most 
useful  in  prairie  chicken  management. 

The  rope  count  is  dangerous  for  the  layman  to  use  during  the 
nesting  season  and  when  young  birds  are  small  (during  the  latter 
part  of  March  through  June),  for  unless  extreme  care  is  taken,  nests 
may  be  broken  up  and  young  birds  injured,  scattered,  or  even  killed 
by  a  fast-moving,  1-inch  rope.  A  i^-inch  rope,  50  yards  long,  how- 
ever, has  been  used  with  success  in  locating  nests  and  broods  without 
detriment  to  the  birds.  Coffee-bean  plants,  yaupon  bushes,  trees, 
and  old  fence  posts  are  obstacles  to  rope  counting,  but  they  can  be 
avoided  without  great  loss  of  time,  and,  with  care,  few  breaks  in 
the  rope  or  cable  result.  Of  course,  cultivated  fields  cannot  be 
traversed  without  injury  to  standing  crops,  and  counting  is  difficult 
and  sometimes  impossible  in  fallow  rice  fields  where  levees  are  high. 
Inexperienced  persons  sometimes  have  trouble  in  keeping  the  proper 
amount  of  slack  in  the  rope  and  in  following  the  car  tracks  which 
are  depended  upon  to  mark  the  inside  margin  of  every  new  belt. 
These  minor  difficulties,  however,  are  rapidly  overcome  by  practice. 


52       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

CAR-DOG    COUNT 

A  car-dog  count  is  made  by  driving  out  an  area  in  belts  40  to 
150  yards  wide  and  releasing  dogs  to  work  the  area  where  birds  are 
known  or  strongly  suspected  to  be.  Necessary  equipment  consists  of 
one  car  and  one  well-trained  dog,  but  two  cars,  with  a  man  and  two 
dogs  in  each,  speed  up  the  work  more  than  100  percent. 

Since  1936  this  method  has  been  employed  in  working  over  25,000 
acres.  It  is  economical  and  is  highly  enjoyable  to  dog  lovers,  but 
it  is  slow.  The  work  of  different  dogs  and  that  of  the  same  dog  at 
different  times  and  under  different  conditions  varies  greatly.  Dup- 
lications in  counts  or  recounts  are  virtually  unavoidable  on  well- 
populated  range,  and  misses  are  frequent.  As  reliable  data  are  diffi- 
cult to  obtain  by  this  method,  it  should  be  used  only  when  other  census 
techniques  are  impossible. 

Using  the  Census 

Censuses  produce  the  most  dependable  information  when  applied 
over  an  entire  management  area.  Where  this  is  impracticable  and 
sampling  is  resorted  to,  care  must  be  taken  to  insure  that  the  selected 
area  is  typical  with  respect  to  vegetation,  topography,  water,  and  the 
like,  and  is  sufficiently  large.  In  a  pasture  consisting  of  60  percent 
flat  grassland  with  little  or  no  brush  and  40  percent  sandhills  covered 
with  live  oak  shinnery  it  would  be  incorrect  to  sample  only  the  sand- 
hill territory  and  apply  the  findings  to  the  flat  grassland  as  well. 
Sampling  should  be  divided  proportionately  between  distinct  environ- 
mental types.  Sample  areas  should  be  at  least  a  section,  or  640  acres, 
in  size,  and  they  should  preferably  cover  2,000  acres.  Thoroughness 
should  never  be  sacrificed  for  extent  of  coverage,  however,  as  accurate 
censuses  made  thrice  annually  on  a  well-chosen  section  over  a  period 
of  several  years  will  yield  infinitely  more  usable  data  than  will  hap- 
hazard counts  sporadically  undertaken  over  more  territory  than  can 
be  conveniently  handled. 

During  the  spring  census,  investigators  should  list  (1)  males,  (2) 
females,  (3)  occupied  courtship  grounds  and  the  number  of  males  at 
each,  (4)  unoccupied  courtship  grounds,  and  (5)  jack  rabbits,  in  areas 
where  they  are  a  common  resident  species,  as  in  the  country  west  of  the 
Brazos  Kiver.  Census  sheets  should  show  also  (1)  name  of  the  pasture, 
(2)  name  of  owner,  (3)  size  of  sample  area,  (4)  exact  location,  (5) 
date  of  census,  (6)  counting  method  used,  (7)  weather,  and  (8)  names 
of  the  investigators.  Additional  notes  taken  should  describe  (1)  the 
type  of  country  censused,  whether  flat  grassland  with  few  weeds, 
rolling  country  with  scattered  myrtle  bushes,  and  so  on ;  (2)  grazing 
pressure,  whether  light,  medium,  or  heavy;  and  (3)  recent  burns  on 
high  or  low  ground,  showing  the  percentage  of  area  burned,  whether 


ATTWATER'S   PRAIRIE    CHICKEN  53 

burn  is  general  or  spotty,  and  the  location  of  unburned  cover.     Care- 
ful compilation  of  data  greatly  facilities  accurate  interpretation. 

If  prairie  chickens  are  numerous  in  the  sample  area,  1  to  every 
10  acres  or  less,  cover  conditions  should  not  be  changed.  Instead, 
steps  should  be  taken  to  insure  that  grazing  and  burning  practices 
will  duplicate  the  conditions  in  future  years.  If  the  birds  are  scarce, 
less  than  1  to  every  10  acres,  and  if  they  have  not  been  overshot,  habitat 
deficiencies  should  be  sought  and  corrected. 

SPRING 

Probable  habitat  deficiencies  limiting  prairie  chicken  numbers  in 
spring  are  scanty,  poorly  distributed,  or  overdense  nesting  cover 
and  a  shortage  of  suitable  courtship  grounds.  Common  causes 
of  deficient  cover  are  general  burning  and  overgrazing  that  result  in 
scarcity  or  complete  absence  over  more  than  60  percent  of  the  area 
of  old  vegetation,  left  from  previous  years  at  an  average  height  of 
at  least  5  inches,  and  poorly  distributed  cover  confined  to  a  particular 
part  of  a  pasture  or  to  low,  poorly  drained  situations.  Undergrazing 
is  the  usual  cause  of  overdense  cover,  the  thick  matted  vegetation  that 
chickens  regularly  avoid.  Where  jack  rabbits  (Taylor,  Vorhies,  and 
Lister,  1936)  are  a  common  resident  species,  they  are  usually  either 
very  nmnerous,  1  to  every  10  acres  or  less,  or  entirely  absent  where 
cover  is  too  scanty  or  too  poorly  distributed  to  be  suitable  for  nesting 
prairie  chickens.  Jack  rabbits  are  frequently  scarce,  1  to  every  80 
acres  or  more,  however,  in  cover  that  is  overdense.  A  markedly  un- 
balanced sex  ratio,  with  more  than  twice  as  many  male  prairie 
chickens  as  hens,  also  has  been  noted  in  pastures  where  nesting  cover 
was  deficient. 

In  areas  in  which  the  cover  is  scarce  because  of  general  burning, 
conditions  are  improved  by  leaving  40  percent  or  more  of  the  grassy 
cover  unburned  each  year.  Unburned  cover  should  be  well  distributed 
over  the  pasture,  the  greater  part  being  on  the  highest,  best-drained 
ground,  in  patches  of  5  to  40  acres.  Favorable  conditions  are  en- 
couraged if  burning  is  carried  on  when  there  is  little  or  no  wind  and 
the  vegetation  is  slightly  damp.  A  quiet  day  following  a  light  shower, 
or  a  still  night  after  the  dew  has  begun  to  fall,  is  preferable.  A  test 
fire  should  be  set  in  a  protected  corner  of  the  pasture.  If  it  burns 
slowly,  consuming  only  the  most  combustible  material,  and  dies  down 
in  6  to  15  minutes,  a  series  of  fires  then  may  be  set  throughout  the 
pasture.  The  number  should  be  strictly  regulated  by  the  acreage  to 
be  burned  and  the  manpower  available  to  curb  the  fires  in  case  of  such 
unforeseen  difficulties  as  a  fresh  breeze  that  may  put  fires  out  of  con- 
trol. The  best  insurance  against  trouble  from  that  cause  is  a  plowed 
fire  lane,  5  to  10  feet  wide,  completely  encircling  the  pasture  and 


54       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

dividing  it  into  blocks  of  approximately  100  acres  each.  All  pasture 
burning  should  be  completed  by  December  or  early  in  January,  well 
in  advance  of  the  nesting  season. 

Moderation  in  grazing  is  important.  Cattle  should  not  be  left  to 
graze  on  a  tract  until  unpalatable  bunch  grasses,  as  smut  grass,  salt 
grass,  big  bluestem,  and  tlie  like,  are  all  that  remain.  Ideal  condi- 
tions are  approached  when  the  number  of  animal  units  is  strictly  regu- 
lated according  to  the  quantity  and  quality  of  the  available  forage. 
This  practice  avoids  a  condition  of  cover  that  is  scanty  in  dry  years 
and  overdense  in  wet  years,  and,  besides  being  favorable  to  prairie 
chickens,  it  conserves  the  soil  and  the  range. 

A  shortage  of  courtship  grounds,  short-grass  areas  from  one-half  to 
10  acres  in  extent  surrounded  by  light  to  medium-heavy  grassy  cover,  is 
frequently  indicated  by  an  unbalanced  sex  ratio  with  more  than  twice 
as  many  females  as  males  or  by  a  preponderant  male  population  of  8 
to  15  or  more  birds  on  each  booming  ground.  Common  causes  of  in- 
adequate courtship  facilities  are  (1)  a  lack  of  hardpan  flats;  (2) 
general  burning,  which  denudes  vegetation  over  a  wide  area  and  causes 
prairie  chickens  to  leave ;  and  (3)  undergrazing,  resulting  in  tall  cover 
even  on  hardpan  areas.  These  deficiencies,  however,  are  remedied  by 
spot  burning  and  moderate  grazing. 

SUMMER 

Probable  deficiencies  that  limit  the  number  of  birds  in  summer  are 
an  insufficient  supply  of  water  in  dry  years  and  inadequate  shade.  A 
count  made  from  July  1  through  August  10,  preferably  over  the  same 
area  covered  in  spring,  reveals  the  number  of  young  produced,  and 
thus  serves  as  a  check  on  the  success  or  failure  of  the  breeding  season. 

The  data  recorded  for  the  summer  count  should  be  the  same  as  for 
the  spring  count  and,  also,  investigators  should  note  (1)  the  number 
of  young,  (2)  the  number,  character,  and  location  of  water  supplies, 
and  (3)  distribution  of  birds  with  respect  to  water  and  weedy  cover. 

A  larger  population  of  adult  prairie  chickens  than  was  found  in 
spring  shows  either  that  the  spring  census  was  inaccurate,  or  that 
other  birds  have  moved  in.  In  the  latter  event  no  habitat  manipula- 
tion should  be  attempted  unless  the  resident  population  plus  the  in- 
flux averages  less  than  1  bird  for  every  10  acres,  and  a  larger  popula- 
tion is  desired.  If  the  adult  population  has  decreased  since  spring, 
however,  and  it  is  established  that  poaching  has  not  occurred,  the 
census  data  should  be  examined  for  information  suggesting  causes 
of  the  decline. 

Indications  of  deficient  water  are  the  absence  of  watering  places  a 
mile  or  less  apart,  and  the  concentration  of  birds  and  jack  rabbits  in 
parts  of  the  area  where  water  is  available.    Indications  of  deficient 


ATTWATER'S   PRAIRIE    CHICKEN  55 

shade  are  the  scarcity  of  prairie  chickens  and  jack  rabbits  where  sur- 
face water  obtains.  Ordinary  causes  of  insufficient  water  are  drainage 
and  unusually  dry  seasons.  Water  supplies  can  be  improved  by  clean- 
ing and  deepening  natural  ponds  or  constructing  new  ones,  and  allow- 
ing windmill  pumps  to  spill  over  and  maintain  puddles  nearby. 

Common  causes  of  inferior  shade  are  heavy  grazing  and  mowing. 
Shade  deficiencies  usually  can  be  corrected  naturally  by  moderate 
grazing  and  leaving  unmowed  plots  1  to  10  acres  in  extent  in  flats 
near  ponds.  Other  methods  of  obtaining  and  maintaining  tall  shading 
cover  are  by  (1)  fencing  tracts  from  %  to  10  acres  in  size  within  100 
yards  of  water  holes  and  leaving  the  fenced  areas  ungrazed ;  (2)  plant- 
ing tamarisk,  chinaberry,  black  locust,  elm,  sycamore,  cottonwood,  or 
other  adapted  trees  near  water  supplies;  (3)  constructing  two  or  more 
brush  racks  5  by  6  by  2  feet  high  on  knolls  on  high  ground  near 
ponds ;  and  (4)  strip  plowing  near  ponds  as  outlined  on  page  56. 

An  increase  of  100  percent  in  the  number  of  prairie  chickens  in  any 
year  is  excellent.  An  increase  of  50  percent  or  less  may  indicate 
either  a  poor  breeding  season  or  abnormally  high  predation.  Rainfall 
records  for  May  show  whether  breeding  conditions  are  poor;  in  the 
event  heavy  rainfall  is  not  the  causative  agent,  predators'  may  be 
responsible.  In  the  latter  instance,  the  number  of  predatory  dogs 
and  house  cats  should  be  reduced  by  shooting  or  trapping.  If  a  thor- 
ough job  is  done  and  yet  the  increase  is  small,  the  aid  of  State  or 
Federal  wildlife  technicians  should  be  solicited. 

WINTEB 

In  winter,  a  grouse  habitat  may  be  deficient  in  food,  cover,  or  both. 
This  may  best  be  determined  by  study  of  information  obtained  during 
a  December  or  early  January  reconnaissance  of  territory  that  was 
covered  in  summer.  Except  for  the  data  on  the  number  of  young 
birds  and  on  the  water  supply,  information  recorded  in  winter  should 
be  the  same  as  that  in  summer,  and  it  should  show  whether  birds  are 
generally  distributed  or  heavily  concentrated  in  small  areas.  The  rope 
count  is  the  preferred  method  of  winter  census,  dog  counts  being  made 
only  when  rope  counting  is  impracticable. 

Assuming  that  poaching  is  not  a  factor,  a  winter  population  larger 
than  that  of  the  summer,  shows  habitat  conditions  on  a  census  area 
already  more  favorable  than  those  in  pastures  nearby  and  suggests  that 
management  be  directed  at  maintenance,  rather  than  at  alteration  of 
environment.  A  winter  population  smaller  than  that  of  the  summer 
suggests  food  or  cover  deficiencies.  Other  indicators  of  such  inad- 
equacies, generally  occurring  together  in  heavily  grazed  areas,  are  a 
prevalence  of  largely  unpalatable  plants,  as  goat  weed,  marsh-elder, 
dogfennel,  perennial  ragweed,  smutgrass  {SporobokiS  poiretii),  and 


56       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

cordgrass;  a  concentration  of  prairie  chickens  in  small  parts  of  the 
area;  and  an  abundance  of  jack  rabbits  (averaging  1  to  every  10  acres 
or  less) ,  or  their  complete  absence.  Indications  that  food  only  is  lack- 
ing are  a  uniform  growth  of  heavily  matted  grass,  a  sparse  growth 
of  weeds,  and  a  scarcity  of  jack  rabbits  (averaging  1  to  every  80  acres 
or  more).  Moderate  grazing  encourages  favorable  food  and  cover 
conditions. 

To  make  up  for  local  shortcomings,  prairie  chicken  managers  may 
establish  (1)  stockproof -fenced  areas  of  i/^  to  10  acres  in  as  large  num- 
bers as  practicable;  (2)  plowed  strips  20  to  50  feet  wide  dividing 
sparsely  inhabited  parts  of  pastures  into  blocks  of  50  to  200  acres;  and 
(3)  unmowed  patches  of  cover  of  2  to  10  acres  or  more,  situated  not 
more  than  300  yards  apart.  Fenced  areas  should  not  be  grazed,  and, 
if  possible,  half  of  each  fenced  area  should  be  planted  annually  to 
Schrock,  German  millet,  dwarf  milo,  hegari  (pi,  14) ,  or  red-top  cane. 
Brush  racks  built  in  the  corners  of  fenced  areas  attract  quails  as  well 
as  prairie  chickens.  In  average  years  strip  plowing  may  be  done 
with  satisfactory  results  from  December  through  April,  but  February 
is  considered  most  favorable.  The  best  effects  on  experimental  areas 
in  Wliarton  County  and  at  College  Station  have  been  obtained  on 
strips  that  were  plowed  shortly  before  or  after  a  rain  and  harrowed 
immediately  after  the  preliminary  breaking.  Unmowed  patches  of 
cover  should  be  left  on  knolls  or  ridges,  in  flats  around  ponds,  or  in 
other  places  where  sizable  stands  of  weeds  occur. 

General  Recommenditions  for  Habitat  Control 

Landowners  who  do  not  undertake  intensive  management  of  prairie 
chickens  based  on  counts  made  three  times  a  year  may  adopt  any 
or  all  of  the  following  general  recommendations  with  the  assurance 
that  some  improvement  will  result: 

Pastures  should  be  grazed  moderately  by  livestock. 

Pasture  burning  should  be  completed  before  February  1 ;  in  excess  of  40 
percent  of  the  pasture  should  be  left  unburned,  with  the  remaining 
cover  v/ell  distributed  in  patches  of  5  to  40  acres  on  the  best  drained 
areas. 

Mowing  should  not  be  done  before  July  1 ;  unmowed  patches  of  2  to  5 
acres  or  more,  not  more  than  300  yards  apart  should  be  left  on  flats, 
knolls,  or  in  other  places  where  there  is  a  good  stand  of  weeds. 

In  summer  windmill  pumps  should  be  allowed  to  form  puddles. 

Predatory  house  cats  and  dogs  should  be  rigidly  controlled. 

The  present  5-year  close  season  (effective  September  1937)  should  be 
enforced.  If  and  when  the  season  is  reopened,  not  more  than  35  percent 
of  the  known  population  should  be  shot  when  rainfall  in  May  is  normal 
or  less.  In  years  when  rainfall  in  May  is  approximately  twice  normal, 
no  birds  should  be  kUled. 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  14 


ATTWATER'S    PRAIRIE    CHICKEN  57 

PREDATOR  CONTROL 

Exhaustive  studies  by  McAtee  (1931, 1932, 1935,  1936),  McAtee  and 
Stoddard  (1930),  Fisher  (1893)),  May  (1935),  and  others  have  dem- 
onstrated rather  conclusively  that  the  food  of  most  flesh-eating  birds 
and  manmials  is  determined  mainly  by  the  availability  of  prey. 
Errington  (1935)  adds  that  predation  is  largely  confined  to  in- 
secure or  surplus  populations;  in  areas  where  there  is  adequate 
food  and  cover,  hawks,  owls,  skunks,  opossums,  and  the  like  feed 
principally  on  the  more  common  rats,  mice,  snakes,  frogs,  and  insects, 
rather  than  on  the  less  numerous,  swift,  and  elusive  game  birds. 
Flesh  eaters  often  are  neutral,  and  may  be  actually  beneficial,  in 
relation  to  sport  and  agriculture.  Specific  data  presented  on  the 
relationships  of  Attwater's  prairie  chicken  and  its  natural  enemies 
(pp.  37  to  40)  are  by  no  means  so  comprehensive  as  desired.  The 
information  at  hand,  however,  apparentl}'^  justifies  the  following 
general  recommendations  concerning  predator  control  on  prairie 
chicken  range : 

Feral  house  cats  and  predatory  dogs  may  well  be  controlled. 

Hawks,  owls,  and  fur  animals  should  not  be  killed  Indiscriminately,  their 
control  being  limited  to  known  offenders.  Inhumane  pole  traps  should 
not  be  used.  (All  raptorial  birds  except  Cooper's,  sharp-shinned,  and  duck 
hawks,  goshawks,  and  great  horned  owls  are  protected  in  Texas.) 

Fur  animals  should  be  taken  only  during  open  seasons  when  furs  are  prime, 
and  the  harvest  should  be  regulated  to  promote  sustained  yields. 

HARVESTING  THE  SURPLUS 

Former  laws  governing  the  shooting  of  Attwater's  prairie  chickens 
left  much  to  be  desired.  Regulations  in  effect  from  1925  through 
1937,  providing  an  open  season  from  September  1  through  September 
4  and  a  bag  limit  of  10  birds  a  day  or  10  a  season,  actually  stimulated 
butchery  and  injured  sport.  Hunting  was  allowed  when  birds  were 
easily  found,  many  being  concentrated  near  patches  of  heavy  cover 
near  surface  water.  Unwary  young  of  the  year  were  easily  shot  be- 
cause they  flushed  near  the  gunner,  flew  straight  and  slowly  for  short 
distances,  and  ran  but  little  after  alighting.  Adults  performed  sim- 
ilarly, probably  because  the  weather  was  warm,  the  cover  dense,  and 
because  they  were  in  molt.  September  heat  prohibited  efficient  work 
by  bird  dogs,  so  crippling  losses  were  doubtless  high.  As  it  was 
also  uncomfortably  warm  for  men  to  walk,  hunting  by  cars,  and 
shooting  from  them,  in  violation  of  State  law,  became  the  rule  in 
Colorado  and  Austin  Counties  and  probably  elsewhere  in  coastal 
Texas. 

In  the  future,  the  power  of  making  regulations  might  well  be 
delegated,  under  proper  safeguards,  to  the  State  Game,  Fish,  and 
Oyster  Commission,  which  has  the  benefit  of  information  and  counsel 


58      NORTH  AMERICAN   FAUNA    57,   FISH  AND   WILDLIFE    SERVICE 

from  its  own  trained  game  protectors  and  from  experienced  sports- 
men, as  well  as  from  wildlife  specialists  connected  with  the  State  and 
Federal  Governments.  This  power  ghould  allow  for  prompt  modi- 
fication of  regulations  in  response  to  emergencies  of  climate,  or  other 
conditions  affecting  the  welfare  of  the  birds.  The  proper  open  sea- 
son on  Attwater's  prairie  chickens,  assuming  that  the  numbers  of 
the  birds  can  be  built  up  to  withstand  the  drain  of  shooting,  cannot 
always  be  determined  in  advance,  and  regulations  should  be  formu- 
lated in  accordance  with  local  conditions  as  they  develop.  The  State 
legislature,  meeting  only  at  2-year  intervals,  must  rely  on  the  State 
Game  Commission  for  appropriate  regulation  of  the  take  of  game; 
and  only  under  that  arrangement  can  the  people  properly  hold  the 
Commission  fully  responsible  for  game  protection. 

If  hunting  is  again  allowed,  seasons  should  not  in  any  case  open 
prior  to  November  15.  Weather  late  in  November  is  usually  suffi- 
ciently cool  for  the  comfort  of  men  and  dogs,  and,  normally,  the 
prairies  are  too  wet  to  allow  hunting  from  cars.  The  prairie  chickens, 
already  congregating  in  winter  packs,  are  widely  distributed  and 
strong  flying;  consequently,  they  are  hard  to  find  and  even  more 
difficult  to  hit.  Probably  because  the  young  of  the  year  are  strong 
and  more  worldly  wise,  and  because  the  weather  is  cool  and  the 
ground  cover  reduced,  late  fall  birds  regularly  flush  widely,  twist 
crazily,  fly  swiftly  and  far,  usually  for  a  mile  or  more,  and  run  after 
alighting.  In  other  words  the  Attwater's  prairie  chicken  in  Novem- 
ber is  a  game  bird  of  the  highest  order;  hunting  it  thoroughly  tests 
the  most  skillful  hunter  and  the  best  bird  dog.  That  is  as  it  should 
be  in  true  sport. 

RESTOCKING 

At  present  the  possibility  that  prairie  chickens  may  be  restored 
by  artificial  planting  is  remote,  as  wild  birds  are  not  available 
for  trapping  and  moving,  and  artificial  propagation  has  shown  little 
promise.  Furthermore,  there  is  no  assurance  that  priarie  chickens, 
if  available,  would  survive  if  moved.  In  Texas  and  Oklahoma,  at- 
tempts to  transplant  lesser  prairie  chickens  have  been  unsuccessful. 
Bent  (1932:  263)  records  the  failure  of  numerous  attempts  to  trans- 
plant the  greater  prairie  chicken  in  northern  States.  A  number  of 
these  birds  introduced  in  the  vicinity  of  the  Sault  Sainte  Marie  and 
McMillan  in  northern  Michigan  persisted  for  a  few  years,  but  F.  F. 
Tubbs,  Michigan  Department  of  Conservation,  writes  that  they  have 
disappeared.  It  is  true  that  no  intensive  efforts  have  been  made  to 
transplant  Attwater's  prairie  chickens  in  southern  Texas,  but  there 
is  no  reason  to  believe  that  they  would  survive  the  process  better 
than  have  their  relatives. 


ATTWATER'S   PRAIRIE    CHICKEN  59 

Natural  restocking,  however,  takeg  place  rapidly  and  efficiently 
when  prairie  chickens  are  properly  protected  and  allowed  to  increase. 
Since  1935  practically  all  suitable  territory  in  Refugio  County  has 
been  restocked  by  natural  spread  from  the  Salt  Creek  Ranch  and 
the  properties  of  Martin  O'Conner.  When  the  birds  are  permitted  to 
increase  elsewhere,  similar  results  may  be  expected. 

SUMMARY 

Attwater's  prairie  chicken,  a  characteristic  bird  of  the  coastal 
prairie,  is  one  of  three  kinds  that  once  occurred  in  Texas.  A  few 
lesser  prairie  chickens,  smaller  and  paler  in  color  than  Attwater's 
subspecies,  still  persist  in  parts  of  the  Texas  Panhandle.  The  greater 
prairie  chicken,  however,  has  been  entirely  extirpated  from  its  former 
habitat  in  the  central  and  northern  parts  of  the  State. 

An  intensive  census  made  in  the  summer  of  1937  revealed  that 
only  about  8,000  to  9,000  Attwater's  prairie  chickens  then  remained 
in  Texas,  approximately  half  of  them  being  in  Refugio  County. 
The  birds  now  inhabit  only  about  450,000  acres,  compared  with  the 
more  than  6,000,000  formerly  occupied.  The  numbers  of  the  coastal 
prairie  chicken  have  declined  99  percent,  and  its  range  has  decreasd 
more  than  93  percent  during  the  past  century. 

The  mating  season  begins  late  in  January  or  early  in  February, 
when  the  males  asgemble  on  short-grass  areas  early  in  the  morning 
and  late  in  the  afternoon  and  boom  and  otherwise  display  the  mating 
urge.  Females  are  attracted  to  the  courtship  areas  by  this  activity, 
and  mating  usually  takes  place  there.  Prairie  chickens  are  pro- 
miscuous.   The  booming  is  at  a  climax  in  March  and  ends  late  in  May. 

Nests  containing  eggs  have  been  found  from  February  25  through 
June  17.  The  peak  of  the  laying  period,  however,  is  late  in  March 
and  in  April.  Females  build  their  nests  in  dry  vegetation  of  the 
previous  year  preferred  nesting  sites  being  in  good  cover  in  well-drained 
areas  and  within  5  yards  of  an  opening. 

The  normal  rate  of  laying  is  1  egg  a  day  until  the  average  clutch 
of  12  is  completed,  but  intervals  of  1,  2,  and  even  3  days  are  not 
infrequent.  Subsequent  attempts  to  nest  may  be  made  if  earlier 
nestings  are  terminated  while  booming  is  still  in  progress.  Second 
and  third  nests  apparently  are  made  in  close  proximity  to  those  previ- 
ously destroyed,  which  probably  jeopardizes  their  chances  for  suc- 
cessful termination.  The  incubation  period  is  23  to  24  days  and 
hatching  occupies  about  2  days  more.  The  peak  of  the  hatching  sea- 
son is  in  May.  Fertility  of  the  eggs  evidently  is  high.  Nest  losses 
in  1937,  however,  were  70  percent  of  13  nests  studied,  and  those  in 
1938  amounted  to  67  percent  of  6  nests. 

30.^07° — il 5 


60       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

vin  1937,  of  broods  on  which  accurate  counts  were  obtained,  48 
averaged  5.48  birds  each.  Mortality  of  young  prairie  chickens  is 
highest  (about  50  percent)  in  the  first  4  weeks  after  hatching  and 
comparatively  low  (about  12  percent)  thereafter,  a  large  share  of  the 
early  mortality  being  in  lost  chicks.  Other  known  causes  of  juvenile 
mortality  include  heavy  or  persistent  rains  during  the  brooding, 
drowning  in  rice  fields,  and  depredations  by  natural  enemies.  Fam- 
ily  disintegration,  although  gradual,  begins  when  the  chicks  are  6 
to  8  weeks  old.  It  is  completed  after  cold  northers  late  in  October 
and  in  November  induce  fall  flocking,  or  segregation  of  the  birds 
into  flocks  according  to  sex. 

Unstable  and  temporary  groups  of  5  to  15  birds  are  common  from 
September  through  early  October,  but  singles,  pairs,  and  trios  pre- 
dominate at  that  season.  As  fall  passes  into  winter,  flocks  become 
larger,  and  in  December  and  January  groups  containing  35  to  300 
individuals  have  been  observed.  Singles,  pairs,  and  trios,  however, 
may  be  found  throughout  the  year. 

Young  prairie  chickens  evidently  spend  their  first  3  weeks  within 
half  a  mile  of  the  spot  where  hatched.  Late  in  May  and  in  June, 
both  young  and  adults  move  to  territory  where  cover  providing  good 
shade  is  found  within  half  a  mile  of  surface  water,  there  to  remain 
usually  until  September.  When  fall  rains  and  cool  weather  come 
and  the  fall  weeds  mature,  the  birds  scatter  widely,  often  becoming 
common  where  scarce  or  entirely  absent  at  other  seasons.  Concen- 
tration into  areas  where  there  is  moderate-to-heavy  cover  and  ade- 
quate food  is  evident  by  November,  and  populations  in  favorable 
areas  fluctuate  little  from  then  through  spring. 

The  food  of  adult  prairie  chickens  is  about  85  percent  vegetable 
matter  and  15  percent  animal.  With  young  birds  the  ratio  of  vege- 
table to  animal  is  approximately  reversed.  Favorite  sources  of  plant 
food  are  ruellia,  perennial  ragweed,  blackberry,  doveweed,  and  sensi- 
tive briar.  Leading  animal  foods  are  grasshoppers  and  beetles. 
Greens  (leaves,  flowers,  buds)  are  lowest  in  the  diet  in  November 
and  December;  seeds  are  taken  in  the  smallest  proportions  in  Jan- 
uary, February,  and  March.  Insects  are  least  frequently  captured 
in  November,  December,  and  January. 

Important  factors  limiting  prairie  chicken  abundance  include  ex- 
cessive or  persistent  rainfall  during  the  nesting  season,  heavy  graz- 
ing, excessive  pasture  burning,  agricultural  operations,  and  over- 
shooting. Other  destructive  factors,  not  generally  serious  but  some- 
times locally  disastrous,  include  oil  development,  drainage,  floods, 
drought,  hurricanes,  hail,  the  spread  of  woody  vegetation  into  prairie 
land,  predation,  pasture  mowing,  and  possibly  disease. 


ATTWATERS    PRAIRIE    CHICKEN  61 

Available  records  from  1925  through  1937  show  a  positive  correla- 
tion on  unmanaged  land  between  the  production  of  young  prairie 
chickens  and  rainfall  in  May.  Good  crops  of  young  chickens  arie 
brought  off  in  years  when  the  rainfall  in  May  is  II/2  inches  or  more 
below  normal.  Fair  broods  are  produced  when  precipitation  in  May 
is  nearly,  or  only  slightly  above,  normal,  while  poor  crops  are  probable 
when  rainfall  in  May  is  about  twice  normal.  If  the  findings  in 
Colorado  County  apply  to  other  parts  of  the  coastal  country,  2  years 
in  5,  on  the  average,  are  favorable  to  prairie  chicken  reproduction^ 
2  are  fair,  and  1  is  poor.  Conditions  affecting  reproduction  are  never 
the  same  for  the  entire  range,  for  a  county,  or  even  for  different  parts 
of  the  same  county,  because  of  the  scattered  character  of  local  rains. 
Attwater's  prairie  chicken  is  a  highly  fluctuating  subspecies,  its 
scarcity  or  abundance  depending  to  a  large  extent  on  the  precipita- 
tion in  May. 

The  annual  kill  of  these  birds  cannot  be  intelligently  regulated  by 
such  general  open  seasons  and  general  bag  limits  as  have  applied 
in  Texas  in  the  past,  but  should  be  set,  when  permissible  at  all,  by 
regulation  by  the  State  Conservation  Department  on  the  basis  of  the 
latest  detailed  information  obtainable. 

Optimum  prairie  chicken  range  apparently  consists  of  well-drained 
grassland  supporting  some  weeds  or  shrubs  as  well  as  grasses,  the 
cover  varying  in  density  from  light  to  heavy;  and  with  supplies  of 
surface  water  available  in  summer.  In  short,  diversification  within 
the  grassland  type  is  essential. 

Management  usually  will  involve  protection  against  excessive  kill- 
ing, improvement  of  food  and  cover,  moderate  control  of  predators, 
and  wise  regulation  of  the  harvest.  Responsibility  for  management 
must  be  assumed  by  the  landowner.  Food  and  cover  deficiencies 
can  best  be  recognized  and  their  improvement  and  maintenance  as-^ 
sured  by  careful  counts  of  the  birds  on  part,  or  all,  of  the  managed 
area  at  three  critical  periods  in  March,  July,  and  December. 

To  obtain  and  maintain  favorable  food  and  cover,  the  following 
general  practices  are  recommended:  (1)  Moderate  grazing  of  pas- 
tures; (2)  completing  all  necessary  pasture  burning  before  February 
1  and  leaving  unburned  not  less  than  40  percent  of  the  best  drained 
ground ;  (3)  mowing  pastures  after  July  1  and  preserving  the  native 
cover  on  knolls,  around  ponds,  and  in  flats;  (4)  allowing  wind- 
mill tanks  to  spill  over  in  summer  to  increase  the  supply  of  surface 
water;  (5)  controlling  the  numbers  of  feral  house  cats  and  predatory 
dogs;  and  (6)  allowing  the  shooting  of  not  more  than  35  percent 
of  the  known  prairie  chicken  population  in  any  year  when  rainfall 
in  May  is  normal  or  below  and  prohibiting  killing  when  rainfall  in 
May  is  approximately  twice  normal  or  above.  Hunting  seasons 
should  not  open  before  November  15. 


62      NORTH  AMERICAN   FAUNA    57,    FISH   AND   WILDLIFE    SERVICE 

Under  normal  conditions  hawks,  owls,  and  fur  animals  do  not 
appear  to  be  serious  predators  on  Attwater's  prairie  chickens,  and 
should  not  be  killed  indiscriminately. 

Persons  should  not  request  the  Government  to  furnish  prairie 
chickens  for  restocking,  because  there  is  no  surplus  for  the  purpose 
and  no  evidence  that  the  birds  can  be  successfully  transplanted. 

In  the  absence  of  ample  reservations  for  the  species  all  other 
favorable  factors  together  cannot  be  counted  on  to  save  the  bird 
from  extinction.  Before  too  late  a  large  tract  or  tracts  of  suitable 
range  should  be  established  as  a  prairie  chicken  refuge  by  the  Federal 
or  State  Government. 

LITERATURE  CITED 

AsKiNs,  Charles  C. 

1931.  Game  bird  shooting.     312  pp.,  illus.     New  York. 
Bailhtt,  Plobence  Mebriam. 

1927.  Handbook  of  birds  of  the  western  United  States.     Ed.  10,  rev.,  590  pp. 
illus.     Boston  and  New  York. 
Bailet,  Vernon. 

1905.  Biological  survey  of  Texas.     U.  S.  Biol.  Survey  North  Amer.  Fauna 
25,  222  pp.,  iUus. 
Bbndire,  Charles  Emil. 

1892.  Life   histories    of   North   American    birds   with    special    reference   to 

their   breeding   habits   and   eggs,   with   twelve   lithographic   plates. 
U.  S.  Nat.  Mus.  Special  Bull.  1,  446  pp. 
1894.  Tympanvchus  americanus  attwateri  Bendire.     Attwater's  or  southern 
prairie  hen.     Auk  11 :  130-132. 
Bent,  Arthur  Cleveland. 

1982.  Life  histories  of  North  American  gallinaceous  birds.     U.  S.  Nat.  Mus. 
Bull.  162,  490  pp.,  illus. 
Brat,  William  L. 

1901.  The   ecological   relations   of  the   vegetation   of  western  Texas.     Bot. 
Gaz.   32:99-123,  195-217,   262-291,  illus. 
Erkinoton,  Paxil  Lesthe. 

1935.  Overpopulation  and  predation:  A  research  field  of  singular  promise. 
Condor  37:  230-232. 
Fisher,  Albert  Kenrick. 

1893.  The  hawks  and  owls  of  the  United  States  in  their  relation  to  agri- 

culture..  U.   S.  Dept.  Agr.  Biol.   Survey    (Orn.   and  Mamin.)    Bull. 
3,  210  pp.,  illus. 
Gkoss,  Alfred  Otto. 

1930a.  The  Wisconsin  prairie  chicken  investigation.     Amer.  Game  19 :  39-40, 

50. 
1930b.  Progress  report  of  the  Wisconsin  prairie  chicken  investigation.     Wis- 
consin Conserv.  Comn.  112  pp.,  illus.     Madison,  Wis. 
Leopold,  Aldo. 

1931.  Report  on  a  game  survey  of  the  North  Central  States.     299  pp.,  illus. 

Madison,  Wis. 
1933.  Game  management.     481  pp.,  illus.     New  York  and  London. 
May,  John  Bichabd. 

1935.  The   hawks  of  North   America.     140  pp.,   illus.     Nat.   Audubon    Soc, 
New  York. 


ATTWATER'S   PRAIRIE    CHICKEN  63 

McAtee,  Waido  Lee. 

1931.  A  little  essay  on  vermin.     Bird-Lore  33 :  381-384. 

1932.  Confusions  of  an  economic  ornithologist.     Bird-Lore  34 :  315-321. 

1935.  Food  habits  of  common  hawks.     U.  S.  Dept.  Agri.  Circ.  370,  36  pp., 

illus. 

1936.  The  Malthusian  principle  in  nature.     Sci,  Monthly  42 :  444-456. 
and  Stoddabd,  Heobebt  Lee. 

1930.  American  raptores  and  the  study  of  their  economic  status.     C5ondor 

32:  15-19. 
Mebkill,  James  Gushing. 

1879.  Notes  on   the  ornithology  of  southern  Texas,  being  a   list  of  birds 
observed  in  the  vicinity  of  Fort  Brown,  Texas,  from  February,  1876, 
to  June,  1878.     U.  S.  Nat.  Mus.  Proc.  1 :  118-173,  1878. 
Obebholseb,  Habey  Church. 

1938,  The  bird  life  of  Louisiana.    834  pp.,  illus.     New  Orleans. 
Simmons,  George  Finlay. 

1925.  Birds  of  the  Austin  region.    387  pp.,  illus.     Univ.  Texas,  Austin. 
Streckeb,  John  Kern. 

1927.  Notes  on  the  ornithology  of  McLennan  County,  Texas.     Baylor  Univ. 
Mus.  Spec.  Bull.  1,  65  pp. 
Stoddard,  Herbert  Lee. 

1931.  The  bobwhite  quail:  its  habits,  preservation,  and  increase.    559  pp., 

illus.    New  York. 
Taylor,  Walter  Penn. 

1934.  Significance  of  extreme  or  intermittent  conditions  in  distribution  of 

species  and  management  of  natural  resources,  with  a  restatement 
of  Liebig's  law  of  minimum.     Ecology  15:  374-379. 
Vorhies,  Charles  Taylor;  and  Lister,  Paul  B. 

1935.  The  relation  of  jack  rabbits  to  grazing  in  southern  Arizona.     Jour. 

Forestry  33 :  490-498,  illus. 
Texas  Game,  Fish,  and  Oyster  Commission. 

1929.  Grouse  or  prairie  chicken.    Ann.  Rpt.  1929 :  86-91,  illus.    Austin,  Tex. 
Tharp,  Benjamin  Carroll. 

1926.  Structure  of  Texas  vegetation  east  of  the  98th  meridian.     Univ.  Texas 

Bull.  2606,  100  pp.,  illus.    Austin,  Tex. 


f'r^ 


INDEX 


Abundance,   6,    7. 
Agricultural  factors,  40. 
americanus,  Tympanuchus,  4. 
attwateri,  Tympanuchus  cupido,  1. 

Brood  size,  18. 

Call,  12. 

Cat,  house,  38,  39,  40. 
Census   methods,  47. 
Coloration,  4,  5,  6. 
Courtship,  10. 
cupido,  Tympanuchus,  1. 

Development  of  young,  16. 
Disease,  36. 

Disintegration,  family,  19. 
Distribution,  2,   (map)  3,  7. 
Drainage,  effect  of,  43. 

Eagle,   bald,  39. 

Flocking,  20. 
Floods,  35. 
Food,  25. 

Goshawk,   39. 

Grouse,  39. 

Growth   of  young,   16. 

Habitat,  30. 

control,   recommendations,   56. 

improvement,   46. 

requirements,  30. 
Hawk,  duck,  39. 

ferruginous  roughlegged,  39. 

Krider's,  39. 

marsh,  39. 

rough-legged,  39. 
Heath-hen,  1. 
Hunting,  effects,  44. 

Increase,  20. 


Limiting  factors,  31. 

Management,  45. 
Mating,  10. 
Mortality,  juvenile,  19. 

Nesting,  14. 

Nests,  predation  on,  37. 

Overgrazing,  effect  of,  42. 

pallidicinctus,  Tympanuchus,  4. 
Pasture  burning,  effect  of,  41. 

mowing,  43. 
Population  status,  8. 
Prairie  chicken,  Attwater's,  1. 

greater,  4. 

lesser,  4,  5. 
Predation,  37. 
Predator  control,  57. 
Protection,  45. 

Quail,  39. 

Rainfall,  32. 
Restocking,  58. 

Seasonal  movements,  21. 
Sparrow,  English,  17. 
Starling,  17. 
Storms,  35,  36. 
Surplus,  57. 

Turkey,  bronze,  17. 

Tympanuchus  cupido  americanus,  4. 

cupido  attwateri,  1,  4. 

cupido  cupido,  1. 

pallidicinctus,  4. 

Weight,  5. 
Wolf,  red,  38. 
Woody  vegetation,  36. 

Young,  development  of,  16. 
predation  on,  38. 


65 


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OCCIDENTAL  COLLEGE  LIBRARY 

149  30:57  jocus 

Attwater  s  prarne  chicken,  i/Lehmann,  V 


3  5043  00322  1677 


DATE  DUE 

Demco,  Inc.  38-5 

293