MONTHLY WILDLIFE RESEARCH LETTER 
natural history survey 
JUN 1 0 1970 
LIBRARY 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
Urbana, Illinois 
May, 1970 
Vol. 13, No. 5 
1. Pheasant Populations and Land Use S. L. Etter, 
R. E. Greenberg 
During the period April 27-May 6 , 1970, systematic counts of pheasants were 
conducted along 57 miles of all-weather roads on the Sibley Study Area. Each 
observation period was confined to the first 2 hours after sunrise, which allowed 
coverage of half the roads each morning. Thus, in eight mornings each road was 
driven four times for a total of 228 miles. Starting points were staggered so 
that no one portion of the study area was consistently covered earlier than other 
portions. Counts conducted during the period April 16-28, 1 969 , followed these 
same criteria. 
These counts revealed little difference in the numbers of cock pheasants 
observed in 1969 and 1970. The counts in 1970 recorded 238 cocks (104 per 100 
miles); 243 cocks (106 per 100 miles) were recorded in l 969 . Winter sex ratios 
obtained during periods of snow cover in 1969 and 1970 were 36 and 40 cocks per 
100 hens, respectively. By using these figures, indices of 675 and 595 hens were 
calculated for 1969 and 1970 , respectively, a decrease of 12 percent. 
In view of the fact that the standardized counts of pheasants in July and 
August 1969 were higher than in 1 968 (MWRL 12(9):1), the lower breeding population 
in 1970 suggests that the survival rate of pheasants during the winter of 1969-70 
was somewhat lower than it was during the winter of 1 968 - 69 . Thus, the prolonged 
period of snow cover during this past winter, compared with the relatively open 
winter of 1968 - 69 , may have had an adverse effect on pheasant survival. 
2. Manipulation of Pheasant Habitat 
G. B. Joselyn 
Un May 12, letters were sent to the cooperating farmers on the Ford County 
Management Unit requesting them to refrain from mowing their roadsides until on 
or after July 31. It was indicated that there were no objections to mowing a 
narrow strip a ong the edge of the roadsides or around field entrances and lanes 
to provide a clear view of traffic. 
The m" h! V |i 1 2 * * 5 ; w f re . erected at road entering the l 6 -square- mi le area, 
ine 20 - by 14-inch steel signs read: 
