MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
T. G. Scott, Editor 
Urbana, Illinois 
February 1958 
Vol. 1, No. 2 
W-30-R-11 W. R. Hanson, R. F. Labisky 
Night-light trapping was completed on the Sibley area for the fall 
and winter of 1957-58, 37U pheasants being trapped and marked with plastic back- 
tags during this period. Trapping mortality was only 2.6 per cent. 
Marked pheasants were seen on 155 occasions during February, and the 
pheasants were individually identified in 106 (68.ii per cent) of these observations, 
Pheasants which were marked during the fall and winter of 1956-57 comprised 10®3 
per cent of the total observations. 
Pheasant behavior was well advanced into that of the early breeding 
season during February on the Sibley area; this same stage in the breeding cycle 
was not reached until early March in 1957* Crowing counts during late February 
reached a frequency of 5*5 calls per 2-minute period; cock calls occurred in¬ 
frequently during this same period in 1957* A definite segregation of sexes 
occurred about mid-February, but the early breeding season movement or "shuffle" 
was not apparent. Adult cocks released courtship behavior (involving hens) and 
antagonistic behavior (involving cocks) patterns early in February; juvenile cocks 
exhibited aggressive behavior patterns later than did the adults, indicating a 
less advanced state of sexual motivation. Fex<r social interactions were noted 
among hens. Among cocks, adults asserted dominance over juveniles in all en¬ 
counters. All interactions between sexes involved only adults, and hens were not 
responsive to cocks. These data substantiate previous findings (1957) which 
showed adults to be earlier and more aggressive breeders than juvenile pheasants. 
The yield of com adjacent to five multiflora rose hedges and that of 
corn on the opposite, clean edge of the field were recorded in fall of 1957o 
The corn yield adjacent to the hedges averaged about 13 per cent lower than that 
of the open edge. 
W-U2-R-7 R. D. Lord 
Early morning roadside and nighttime spotlight censuses of rabbits on 
the Sibley area indicated a decline in population*. The roadside census figure 
Ttfas down to 0.15 rabbits per mile from 0*36 last month. Some of this decline 
resulted from decreased visibility when snow disappeared. The spotlight census 
OCT 9 1959 
NATURAL 
HISTORY SURVEY 
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