MONTHLY WILDLIFE RESEARCH LETTER 
fi/srdRir survey 
MAR 4 1981 
LIBRARY 
Illinois Federal Aid Projects W-66-R, W-37-R, and U-3C-R 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Eva Steger, Editors 
So 
Urbana, Illinois October, 19Vol. 23, No. 10 
Manipulation of Pheasant Habitat - W-66-R R. e. Warner 
Last month (MWRL 23(9):1) we indicated that breeding populations of 
pheasants on 5 study areas in east-central Illinois had recovered from winter 
storm-related mortality to the approximate level of abundance noted in 1977. 
Numbers of hatched nests on the Ford County Management Unit (FCMU) were congruent 
with the noted level of recovery. 
However, late summer brood censuses on the FCMU, Sibley Study Area (SSA), 
and Anchor, Harwood, and Prairie Green areas show no improvement over 1979 in 
the rate of recruitment of young into the fall population (Table 1). For all 
areas, an average of h.b broods was observed per 100 miles of driving in August 
1930, indicating little increase over the 3-9 per 100 miles observed in 1979. 
Numbers of chicks observed per brood decreased from 5.9 in 1979 to *>.7 In 1930. 
The disparity between observed broods and the greater numbers of Juveniles 
expected from the spring population data has no obvious explanation. The 6 
weeks following the mid-June peak of hatches were unusually hot and dry; this 
weather may have impaired the survival of young pheasant chicks. Although other 
studies have noted that hot, dry periods may reduce survival rates of broods, 
there are no empirical data that relate mortality to similar weather conditions. 
Possibly our brood counts were biased by the infrequency of optimal 
censusing conditions: relatively cool mornings with heavy dew. However, the 
differences between counts taken in 1930 under relatively good and poor 
conditions were small. 
Hunter harvest data, to be collected in November, may provide further 
insights into the poorer-than-expected recruitment of juveniles into the fall 
pheasant population on the study areas. 
Table 1, August bpoods observed per 100 mijes of driving |n 5 study areas in 
centra] Ijlinois, 
Year 
SSA 
FCMU 
Anchor 
Harwood 
Pral rle 
Green 
1977 
2.3 
26.9 
5.2 
7.0 
5.7 
1978 
1.0 
0.6 
2.0 
4.3 
2.5 
] 979 
2.9 
b.k 
0.7 
7.5 
3-9 
1980 
2.3 
4,4 
5-7 
5.0 
4.6 
