MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
T. G. Scott, Editor 
Urbana, Illinois 
April, 1961 
Vol. k, No. h 
W-30-R-1U 
R. F. Labisky, R. I. Smith 
Fifty pheasants were trapped by night-lighting and marked with plastic back- 
tags during the first week of April on the Sibley area. These birds, all trapped 
within a LO-acre hayfield, will be observed throughout the spring and summer, and 
eventually some of the broods produced by this group will be trapped and marked 
for the purpose of studying dispersal of members of the brood. 
Crowing counts have been conducted over a standard 20-mile route twice each 
week. Behavior and movement of marked pheasants have been observed and recorded 
as the spring dispersal from winter concentration areas occurred. The Sibley area 
pheasant population remains at a relatively high level, and the ice and enow storm 
of April 16 caused no serious mortality, 
W-U2-R-10 R. D. Lord, Jr., D. A. Casteel 
The radio tracking system for rabbits has been developed and is now 
operational. Two rabbits have been equipped with transmitters and have been 
successfully tracked on the Allerton U-H area. Preliminary results sh aw consider¬ 
ably less wandering than might have been suspected on the basis of trap records. 
The second year of the long-term project designed to determine regional and 
yearly differences in mortality rates of cottontails by collecting eyes during the 
hunting season resulted in an increase in the total number of eyes received over 
the previous'year. During the first year 909 eyes were received; this year the 
number was 1,699. Twenty-six counties were represented in the sample for each 
year; however, the counties were not the same for each year. Examination of the 
data and corollary data from the rural mail carrier census of rabbits made in 1998 
suggested that for the purpose of analyzing cottontail mortality the state may be 
divided into three parts: (1) the prairie counties, (2) the southern counties, and 
(3) the western and northwestern counties. The following table shows the average 
age in months of rabbits in the three regions for the first two years of this study. 
