Vo 1. 6 > No * 6 
Page 4 
4. Rabbi t Management W. R. Edwards, D. A. Casteel 
During the fall and winter of 1962-63, lenses of 278 rabbits from four study 
areas were obtained. Table 5» Most of these had been taken by hunters. Age rat¬ 
ios of these samples varied from 91.2 percent young-of-the-year in east-central 
counties to 83*2 percent in the Jasper County collection. These differences 
suggested possible variation in reproductive performance and survival of cotton¬ 
tails among the areas studied. This was supported by a statistical test which re¬ 
vealed a 90-percent probability that observed differences were not due to chance. 
Table 5» Age ratio of cottontail populations sampled during the fall and win¬ 
ter of 1962 - 63 . 
Area 
Juveniles 
Adults 
Total 
Percent Juvenile 
East-central counties* 
83 
8 
91 
91.2 
Allerton Sanctuary 
29 
5 
34 
85-3 
Neoga Area 
88 
11 
99 
88.9 
Jasper County 
45 
9 
54 
83.3 
Total 
245 
33 
278 
88.1 
*Ford, Livingston, McLean, Iroquois 
The age composition of these collections, except Jasper County, contained an 
above-average proportion of young-of-the-year rabbits (an earlier study based on 
12,479 lenses from Illinois, Missouri, Ohio, and Wisconsin collected over a 3-year 
period revealed 83.2 percent juveniles in the fall population is normal for cotton¬ 
tails). Such high juvenileradult ratios are generally considered to reflect good 
reproductive success. Recent evidence suggests that high age ratios are typical of 
rabbit populations which had previously experienced above-normal mortality and be- 
low-normal density. This was apparent both at Allerton and in the east-central 
counties last year and has previously been reported in studies of rabbit populations 
in Ohio. 
A possible explanation for this phenomenon is that homeostatic mechanisms of 
population control compensate for low density and high mortality with increased 
reproduction and survival. Rabbit counts made on the Sibley area and at Allerton 
in 1962 support this hypothesis, as both areas had very low populations at the 
start of the breeding season. 
Where populations contain more than 83 percent juveniles, the game manager 
should be primarily concerned with reducing natural mortality during fall and winter. 
Where populations consistently contain a lower segment of juveniles, the manager 
should consider the possibility of increasing the legal harvest as well as attempt¬ 
ing to increase carrying capacity. 
5. Responses of Bobwhites and Prairie Chickens to Habitat Manipulation 
J. A. Ellis and R. J. Ellis 
Fifty-four quails (51 cocks and 3 hens) were captured in cock-hen traps during 
