December, 1958 



Scott: Wildlife Research 



187 



chickens in all of Illinois' 102 counties 

 except 10 (Yeatter 1957:8). Despite an 

 exaggerated confidence in protective regu- 

 lations, Forbes {\9l2b-A8) recognized 

 the basic environmental factor which was 

 limiting the prairie chicken population be- 

 cause he advised that : 



The very country in which it was formerly 

 most numerous — that is, the open prairie — 

 is now least favorable to it because of the 

 agricultural operations, which disturb and 

 destroy it during its breeding season. 



When it again became evident that the 

 prairie chicken population was endan- 

 gered, Director Bradford of the Depart- 

 ment of Conservation, at the urging of 

 Dr. Thompson of the Natural History 

 Survey, obtained legislation, effective July 

 1, 1933, to prohibit the taking of the 

 prairie chicken at any time. No open sea- 

 son on this bird has been permitted since 

 that date. 



It seems fitting that, with the upsurge 

 of interest in wildlife conservation in the 

 1930's, one of the first comprehensive 

 studies of a game species to be undertaken 

 in Illinois was concerned with the prairie 

 chicken. The valuable monograph (Yeat- 

 ter 1943) resulting from this study in- 

 cludes data on early distribution, range, 

 life history, populations, mortalit\' causes, 

 food habits, and management. 1 believe 

 that this publication was the first to direct 

 attention to the importance of grass-seed 

 farming in the management of prairie 

 chickens. Yeatter (1943:409) advised 

 that areas harboring a few prairie chick- 

 ens 



might be converted into good chicken range 

 by leasing, and converting to refuges for a 

 term of years, 25 per cent of the total land 

 in the form of 20-acre, 40-acre or larger 

 tracts of the poorer farm soil throughout each 

 township. 



In a later publication Yeatter (1957:8) 

 revised his recommendation on grassland 

 refuges to a minimum of 40 acres in each 

 square mile of farm land. 



When unusually large numbers of 

 \oung prairie chickens were found dead 

 on a study area in Jasper County in 1935 

 and 1936, an investigation of parasites as 

 a possible cause of these deaths was un- 

 dertaken (Leigh 1940:186). Tapeworms 

 were found in 10 of 14 partly grown birds 

 and in not one of 14 adults which were 



collected in Jasper and Richland counties 

 in the summers of 1936 and 1937. 



Because cestodes of a previously undescribed 

 species of Raillietina occurred in 10 [ac- 

 tually 9] of 14 young birds and in 4 cases 

 were so numerous or so large as to occlude 

 the lumen of the greater part of the small 

 intestine, they should not be overlooked as 

 a factor in prairie chicken mortality (Leigh 

 1940:188-9). 



Shelford 5c Yeatter (1955) interpreted 

 year-to-year population fluctuations of 

 male prairie chickens during a period of 

 18 years on the study area near Hunt in 

 Jasper County, Illinois, in relation to 

 weather and climate. Field observations 

 indicated that the period of the late stages 

 of development of the reproductive cells 

 during April, the period of egg-hatching 

 in June, and the period when young prai- 

 rie chickens were 4 to 8 weeks old were 

 critical times in the reproductive cycle of 

 prairie chickens. Many trials in which 

 various weather records were used showed 

 that the population level tended to re- 

 spond to only two weather combinations: 



(1) rainfall and sunshine in April and 



(2) rainfall and temperature in June. 

 Reproduction was most successful in sea- 

 sons when April rainfall averaged 2—5 

 inches and when 48-64 per cent of the 

 possible hours of sunshine were experi- 

 enced. As the amounts of rainfall and 

 sunshine varied from these optimum lim- 

 its, reproductive success became progres- 

 sively lower. 



Thus, the prairie chicken in Illinois has 

 passed from the enormous populations of 

 Civil War times to small, scattered colo- 

 nies, in only 24 counties in 1957 (\'eatter 

 1957). It seems evident that the prairie 

 chicken will soon become something of 

 the past in Illinois unless a positive pro- 

 gram of management :^uch as that being 

 proposed at the present time saves them. 



The Bobwhite Quail. — To the up- 

 land bird hunter of Illinois, events which 

 established the present boundaries of Illi- 

 nois proved inadvertently provident, for 

 they led to the inclusion of excellent quail 

 range over the southern one-third of the 

 state as well as what was to become fairly 

 good pheasant range in the northern one- 

 third. 



Illinois has the distinction of being the 

 locale of the first systematic and extensive 



