V/ol . 7 , No . 12 
Page 2 
decreased slightly (7-3 percent) on the managed control plots. However, because 
the acreages searched on the two types of plots differed from I 963 to 1964, actual 
numbers of nests are not as highly indicative of changes in densities of nests be¬ 
tween the 2 years as are establishment figures on an acreage basis. There was no 
great difference between the per acre nest densities for the two types of plots in 
1963, but in 1964 there were nearly 1.8 times as many nests per acre established 
on the seeded plots as on the managed control plots. 
Statistical tests were used to determine whether a significant difference 
existed between the number of nests established on seeded plots and the number 
established on managed control plots during these 2 years. In 1963. the numbers 
of established nests did not differ significantly between the two types of plots 
(%-f = 0.48; Z-^]n = 2.70* l n '964, the difference was highly significant (X^ = 
7-94; ^ 2 oo 5 = 7.88). 1 
Table 2. Number of established pheasant nests, and number of established nests per 
acre, on seeded and on managed control roadside plots, Sibley Study Area, 1 963 and 
1964. 
Year Acres 
Number of 
Established 
Nests 
Number of 
Percent Change, Established Percent Change, 
1963 to 1964 Nests per Acre 1963 to '9&4 
Seeded Control Seeded Control 
Seeded Control Seeded Control 
Seeded Control 
1963 15.37 15.03 44 41 
1964 17.87 17.65 68 38 
2.86 2.73 
+54.5 -7-3 3.81 2.15 
+33.2 -21.2 
3- Factors Inf1uencinq Distribution and Abundance of Pheasants W. L. Anderson 
Pheasants were captured by night1ighting on the Bellmont Study Area during 
October and early November, 1964, to (1) obtain a general index of abundance of 
pheasants on the area, (2) determine the sex and age composition of the population, 
and (3) obtain a series of body weights of pheasants reared on the area. During 
21.8 truck-hours of night1ighting, 85 pheasants were found and 51 (26 cocks and 25 
hens) were captured. Thus, averages of 15-4 and 25-6 truck-minutes of night1ighting 
were expended, respectively, for each bird found and each bird captured. During 
November 1 96 3 > an average of 12-7 truck-minutes of night1ighting was expended for 
each bird captured on the area (38 birds captured during 8.0 truck-hours of night¬ 
lighting). These indices suggest that the abundance of pheasants at Bellmont 
declined about 50 percent from the prehunt period in 1963 to the prehunt period in 
1964. 
The sex ratio among the 85 pheasants found during the prehunt period in 1964 
was I 36 cocks per 100 hens. Age ratios, expressed as juveniles per adult, were 
7.7 and 2.6, respectively, among the 26 cocks and 25 hens captured, indicating that 
reproductive success was good on the area in 1964. 
With respect to body weight, juvenile cocks and hens more than 14 weeks old 
averaged 2.7410.05 pounds (18 birds) and 1.9410.03 pounds (9 birds), respectively. 
These weights are similar to those of juvenile cocks and hens within the established 
pheasant range of Illinois. 
