Vol . 8, No. 6 
Page 3 
Table 2. Percentage of pheasant broods, observed at various ages, that were 
accompanied by hens, Neoga, Illinois, i960 through 1964. Numbers of broods observed 
are in parentheses. 
Age 
(in weeks) 
Date Broods Were Observed 
June 
July 
August 
Sept. 
A11 Months 
0-3 
100(18) 
100 (6) 
100(3) 
(0) 
100(27) 
*f-5 
89(19) 
91(32) 
100(5) 
83 (6) 
90 (62) 
6-7 
0 (2) 
53(49) 
86(14) 
100 (2) 
60(67) 
8-9 
(0) 
68(34) 
43(35) 
0(3) 
53(72) 
10-11 
(0) 
50(4) 
54(24) 
50(2) 
53(30) 
A11 Ages 
90(39) 
69(125) 
59(81) 
62(13) 
69(258) 
4. Responses of Bobwhites to Habitat Manipulat ion 
J. A. Ellis, R. L. Westemeier 
Information on the age structures of the quail populations on the Forbes, 
Dale, and Alma study areas was collected during the fall harvest of 1964 and the 
spring trapping period of 1965* The spring trapping was done with cock-and-hen 
traps, using hen quail as bait, which accounts for the large proportion of cocks 
in the spring samples (Table 3)• 
The proportions of adult males in the quail populations on all three study 
areas decreased from fall to spring (Table 3), thus indicating an age differential 
in wint.r mortality. The consistency of this overwinter shift to smaller proportions 
of adult males implies that the difference in survival rates was probably not related 
to habitat, because the quantity and quality of quail habitat differ markedly among 
the three areas. The chi-square test was applied to the data on proportions of 
adult and juvenile cocks in the populations to determine whether differences in age 
ratios were significant. Highly significant differences were detected (P< 0.005; 
= 22.21, 9-78, and 79*45 for the Forbes, Dale, and Alma areas, respectively, 
df=l). 
Calculations of differential survival rates of age-classes (cocks) were made 
with the use of the following formula, 
where 
N ^ = number of juveniles during the fall period, 
N . = their survival rate, 
N sc = number of juveniles surviving at the end of the winter period, 
N ^ = number of adults during the fall period, 
N . = their survival rate, 
o i 
T = number at the end of the winter period, 
oc 
N 
N 
sb 
ob 
N . 
s i 
N 
N 
sc 
oc 
or 
