Vo I. 9, No. 3 
Page 2 
Table 1. Numbers of adults and of juveniles, and corresponding age ratios," in 
hen pheasant samples from the Sibley Study Area; calculated survival rates of 
juveniles relative to adults; age compositions of expected posthunt samples, 
assuming a constant relative survival rate; and the calculated chi-square value 
for the difference between observed and expected numbers in the posthunt samples. 
1962-63 
1963-64 
1964-65 
1 965“66 
Tota 1 
Observed Prehunt ! 
Samp 1e 
Adu 1 1 9? 
292 
219 
120 
91 
722 
Juveni 1 e 99 
763 
375 
181 
149 
1 ,468 
Age Ratio 
261 
171 
151 
164 
203 
Observed Posthunt 
Samp 1 e 
Adult 99 
150 
68 
83 
50 
351 
Juveni1e 99 
200 
66 
51 
43 
360 
Age Ratio 
133 
97 
61 .5 
86 
102.5 
Survival Rate Relative to Adu 
it 99 
Juveni1e 99 
• 51 
.57 
.41 
• 525 
.505 
Expected Posthunt 
Sample 
Age Ratio 
132 
86 
76 
83 
Adult 99 
151 
72 
76 
51 
Juveni1e 99 
199 
62 
58 
42 
Difference from Observed Posthunt Sample 
Adult 99 
1 
4 
7 
1 
Juveni1e 99 
i 
4 
7 
1 
X 2 (3 df) = 2.026 
Not significant (X 2 .90 = 
6.25) 
* Number of juven 
i 1 e fema 1 es 
per 100 adu 1 t 
females . 
2. Manipulation 
of Pheasant 
Habitat 
G 
. B. Joselyn 
The reduction of hayfiel 
d nesting cover for pheasants, which beg< 
an in 1957, 
has continued; hayfields occurred on 21 percent of the 
Sibley Study Area in 1957 
but on only 4 percent of the 
area in l 965 • 
Data strong 
ly suggest that because of 
this trend in land use, the pheasant population cannot 
continue to maintain itsel 
at I 96 O -63 levels 
unless a suitable alternate nesting cover is provided. 
Although there was no substantial difference between the per acre nest 
densities for the seeded and for the managed control plots in 196 3 > in '964 there 
were 1.6 more nests per acre established on seeded plots than on the managed 
controls, and 2.2 more nests per acre than on the unmanaged control plots (A and B 
plots combined. Table 2). 
