Vol . 7, No. 12 
Page 3 
4. Responses of Bobwhi tes to Habi tat Man ipu1 at ion 
J. A. Ellis, R. L. Westerneier 
Ninety-six bobwhites were captured by night1ighting on the Forbes, Dale, and 
Alma study areas during the fall of 1964. Forty-nine quail were captured on Forbes, 
18 on Dale, and 29 on Alma. Age ratio among the 96 quail was 4.6 juveniles per 
adult or 82.3 percent juveniles in the sample. Cocks and hens occurred in almost 
equal numbers among the juveniles, but the adult sex ratio favored cocks. The high 
proportion of juveniles indicated good reproductive success in 1964. Although the 
number of quail captured on each area was small, the 88.9 percent juvenile segment 
in the Dale sample was believed to be representative, because a high rate of summer 
gain, 522 percent, was indicated when the results of the prebreeding census were 
compared with those of the prehunt census. 
The nightlighting technique for capturing quail was less effective in the fall 
of 1964 than in the fall of 1963- In 1964, 38.1 percent (average) of tie quail 
flushed were captured. The average for 1963 was 50.0 percent. Extremely dry 
weather during the trapping period in 1964 could have caused quail to roost in rough 
terrain near water, making them inaccessible to night1ighting vehicles. The fact 
that 16 of the 18 coveys located on the Dale Area during the prehunt census were 
within 100 yards of water tends to support this suggestion. 
5 . Responses of Prairie Chi ckens _to Habitat Man i pu 1 at ion R. J. Ellis 
It has been reasonably well established that the most critical need of the 
waning populations of prairie chickens in Illinois is suitable nesting cover 
(Yeatter 1963:745, 749)- Studies at Bogota show that grasslands undisturbed during 
the nesting period were nearly indispensable for successful nesting (Monthly WiId- 
life Research Letter, October, 1964). In view of these findings, any management of 
prairie chickens in Illinois should consider the status of grasslands suitable for 
prairie chicken nesting. 
In order to detect trends in acreages devoted to grasslands, the cover on 10 
areas where prairie chickens are censused annually (Monthly Wildlife Research Letter, 
April, 1964) was mapped to show land use in 1 96 3 and 1964 (Table 3)- On each census 
area the total acreage of grass undisturbed during the nesting period (grass hay, 
grass*) declined from 1963 to 1964 whereas the acreage of grain crops increased. 
Apparently this trend has been going on for several years (Yeatter 1963:74-0• In 
most areas of Illinois where chickens once lived, grasslands have become so scarce 
that the chickens disappeared. Unless some grassland suitable for nesting is 
preserved, the prairie chickens of Illinois will completely disappear. 
