MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
T. G. Scott, Editor 
Urbana, Illinois 
May 1958 
Vol. 1, No, 5 
W-30-R-11 W, R. Hanson, R. F. Labisky 
The Job Completion report on the population characteristics of 
pheasants of the Sibley study area was finished during the month. Field study 
of pheasant nesting was conducted; the study plots were cover mapped, and the 
strip cover was searched for nests. 
W-U2-R-7 R. D. Lord 
On the 100-acre Robert Allerton Park study area on which hunting is 
done, the sites of the deaths of rabbits were located from mats of rabbit hair. 
Thirty-two such mats were found during two searches made in December and March, 
Two of 22 hair mats (9,1 per cent) contained shot. Controlled experiments 
determined that there was a 7 per cent loss to be expected in the technique used 
for locating shot in hair mats. Thus, a maximum of 16.1 per cent of the hair 
mats contained shot. 
Further calculations indicated that a maximum of 8,8 per cent of the 
winter mortality on the study area was due to crippling loss. 
X-ray photographs of 3h rabbits trapped alive during the hunting season 
revealed only one carrying shot. Other X-rays of 7 rabbit carcasses found on 
the study area during the season showed no shot. Autopsies of rabbit carcasses 
revealed hemorrhagic pneumonia, suggesting a virus as the etiological agent. 
Research is being started on the nature of fecal pellets of cotton¬ 
tails and the rate of their decay. Among the surprising preliminary findings 
is the discovery that male rabbits have pellets 29 to hi per cent smaller than 
females. This puts the male pellets in the same size class as those of juveniles 
one or more months old, thereby invalidating the work of some earlier workers 
who determined the proportion of juveniles in the late summer population on the 
basis of pellet size. 
nm q 
NATURAL 
HISTORY SURVEY 
