MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
Urbana, Illinois 
September, 1 965 
Vol. 8, No. 9 
1 . Pheasant Populations and Land Use 
W. J. Francis, S. L. Etter 
In 1965, as in the previous 8 years (1957-64), nesting data were collected 
by searching the northwest one-quarter (10 acres) of 100 randomly selected 40- 
acre plots for pheasant nests; this 1,000-acre sample represented 4.3 percent of 
the 23,200-acre Sibley Study Area. In 1965, 107 nests were located on this sample 
and 23 (21.5 percent) of these nests hatched. These data represent a 56-9 per¬ 
cent decrease from the number of established nests (248) and a 20.7 percent de¬ 
crease from the number of successful nests ( 29 ) found on the 1,000-acre sample 
during 1964. 
William J. Francis joined the staff on September 1, 1965, as project leader. 
Dr. Francis received his Ph.D. degree in zoology from the University of California 
at Berkeley in September, 1965• He conducted graduate research on the effect of 
weather on changes in populations of California Quail ( Lophortyx ca1ifornicus ) . 
2. Manipulation of Pheasant Habitat G. B. Joselyn 
Fifteen of 52 pheasant nests (28.8 percent) established on seeded roadside 
plots in 1965 were successful, as compared with 14 of 68 nests (20.6 percent) in 
1964 and 17 of 44 nests (38.6 percent) in 1 96 3 (Table 1). The rate of nest 
abandonment on seeded plots increased each of the last 2 years, and, at 25-0 per¬ 
cent in I 965 , was more than double the rate of the first year (1963) of the study, 
11.4 percent. The percent of nests destroyed* by mammalian predators increased 
from 34.1 in 1 96 3 to 57-3 in 1964 but decreased to 46.1 percent in 1965- Avian 
predators, farm machinery, humans, and unknown causes accounted for 15-9 percent 
of the nests destroyed* in 1963 , but accounted for only 1.5 percent in 1964 and 
for none in 1965- Thus, there was relatively little change between 1 96 3 and 1964 
in the proportionate losses of nests from destruction* due to mammals, birds, farm 
machinery, humans, and unknown causes--50.0 percent of the nests in 1963 and 58.8 
percent in l964--but a slight decline in 1 965 when these factors affected 46.1 
percent of the nests. 
On managed control plots, a higher percentage of the established nests 
hatched in 1965, 24.2 percent (8 of 33 nests), than in either of the preceding 2 
years, I 7 .I percent (7 of 41 nests) in 1 96 3 and 13-2 percent (5 of 38 nests) in 
1964. In contrast to the rate of nest abandonment on seeded plots, the rate on 
managed control plots decreased from 36.6 percent in 1963 to 21.1 percent in 1964 
and to 18.2 percent in 1965• The trend in the percentage of nests disrupted by 
mammals and other factors was nearly the same as for seeded plots--increasing from 
46.3 percent in I 963 to 65.8 percent in 1964 and decreasing to 57-5 percent in 
1965. 
* Some of these nests may have been abandoned first. ImATURAL HISTORY SURVEY 
OCT 14 1965 
LIBRARY 
