MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
T. G. Scott, Editor 
Urbana, Illinois 
July 1958 
Vol. 1, No. 7 
W-30-R-12 W. R. Hanson, R. F. Labisky 
A survey of the use of major cover types by pheasants was evaluated. 
During the breeding season of 1958 on the Sibley area, loafing pheasants were 
distributed more or less at random throughout the available herbaceous cover 
and plowing, but feeding pheasants were observed near forage crops more often 
than expected on the basis of the area of such crops. Feeding pheasants were 
more often seen near tall forage crops than forage crops of lesser heights; the 
reverse was true of loafing pheasants. Loafing pheasants made greater use of 
fields of forage plants in which cattle were feeding than they did of unpastured 
fields. The percentage of pheasants seen near woody cover was about the same as 
that for the previous winter; evidently, weather conditions have little effect 
on the degree of use that pheasants make of woody cover in Illinois. Relative 
to their area, pheasants used self-established clumps of native shrubs more 
frequently than non-native, planted shrubs and trees. 
Data collected on the Sibley study area during 1957 indicated that the 
annual mortality rate was 52.3 per cent for breeding hens and 5U.3 per cent for 
adult cocks. The mortality rate of young pheasants from hatching (1957) to 
January, 1958, was 75.U and 78.5 per cent for hens and cocks, respectively. 
The pre-hunt pheasant population was comprised of 82.5 per cent young 
birds in 1956, but only 71.2 per cent in 1957. Preseason age ratios were 6.8 
and 3.2 young pheasants per adult hen in 1956 and 1957, respectively. 
The change in sex ratios from preseason to postseason indicated a cock 
harvest of 73.3 per cent during the 1956 hunting season but a kill of only 20.3 
per cent during the 1957 season. The reduction of kill in 1957 was thought to 
have been brought about primarily by the large amount of unpicked corn on the 
area early in the season. 
The January, 1958, population of pheasants on the 23,200-acre Sibley 
area was calculated to be 2,879 birds, or 27.2 per cent greater than the January, 
1957, population of 2,261* pheasants. The population of hens, however, showed no 
change between years; the increase in the population was represented by cocks. 
The January populations were comprised of 19.0 and 36.1 per cent cocks in 1957 
and 1958, respectively. Although the rate of reproduction was poorer in 1957 
than in 1956, the decline in production was partially compensated by the large 
breeding population of hens in 1957. Thus the increase in the 1958 winter 
OCT 9 1959 
NATURAL 
HISTORY SURVEY 
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