MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
Urbana, Illinois September, 1971 Vol. 14, No. 9 
1. Pheasant Populations and Land Use G* B. Joselyn 
Standardized counts of pheasant broods, made on the Sibley Study Area 
during July and August 1971, recorded 23 percent fewer broods than in 1970. 
One hundred thirty-nine broods were observed along 640 miles of roadside 
transect (two 40-mile routes were driven each week); 180 broods were observed 
in 1970. The average size of broods judged to be completely counted was 4.5 
chicks, a decrease of nearly 12 percent from the average of 5*1 chicks in 
1970. 
The number of adult hens observed along these same 640 miles decreased 
from 163 in 1 970 to 157 in 1971 (almost 4 percent). Thirty-two percent of 
the adult hens observed in August 1971 were broodless, compared with 22 
percent in August 1970. 
The above indices suggest a slight decrease in pheasant numbers in 
late summer 1971, compared with 1970. 
2. Manipulation of Pheasant Habitat G. B. Joselyn 
Densities of pheasant nests in 1971 on seeded roadside plots averaged 
3.5 nests per acre. Only in 1964 (3*8 nests per acre) was there a higher 
nest density during the 9 years of this investigation, 1963-71* The nest 
density this past summer was 25 percent greater than in 1970 ( 2.8 nests 
per acre). Low nest density for the 9 years was recorded in 1969 (1*7 
nests per acre). 
The nest density on managed control roadside plots in 1971 was 2.4 
nests per acre, up 60 percent from 1.5 nests per acre in 1970* The density 
of 2.4 nests per acre in 1971 was also the second highest density on this 
type of roadside over the past 9 years; the highest density for the period 
was 2,8 nests per acre in 1963* 
T. Ecology and Management of Squirrels C. Nixon, 
-- R. Greenberg 
Only about 60 percent of the yearling (10-14 months) female gray 
squirrels breed during either of the two major breeding periods each year 
(HWRL 14(3):2). l/hile the factors responsible for the attainment of 
puberty are not well defined for the gray squirrel, differences in body 
