MONTHLY WILDLIFE RESEARCH LETTER 
APR t 
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Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
Urbana, Illinois 
March, 1969 
Vol . 12, No. 3 
1. Pheasant Popu1 ations and Land Use S. L. Etter, R. E. Greenberg 
Because of the unbalanced sex ratio of adult pheasants and the nearly even sex 
ratio of juvenile pheasants, t e overall sex ratio of the population is dependent 
upon the relative numbers of ju/eniles and adults. In 1962, for example, the overall 
sex ratio of 1,670 pheasants ca tured during prehunt trapping (October 1-November 11) 
was 75 cocks per 100 hens. Sex ratios within age groups were 20 and 95 cocks per 
100 hens for adults and juveniles, respectively. The overall sex ratio of 413 
pheasants captured during posthunt trapping (January 1-February 28) was 18 cocks 
per 100 hens. Thus, the apparent reduction in the proportion of cocks as a result 
of hunting was 57 cocks per 100 hens, or 76 percent of the 75 cocks per 100 hens 
in the prehunt population. 
However, the ratio of juvenile hens to adult hens in the posthunt sample (133 
per 100) was only about half as great as that in the prehunt sample (278 per 100). 
By using the sex ratios of adult (20 cocks per 100 hens) and juvenile pheasants 
(95 cocks per 100 hens) from the prehunt sample, and a juvenile mortality rate 
based on hens, a theoretical sex ratio in the absence of hunting was calculated for 
the posthunt sample. This figure, 63 cocks per 100 hens, indicated a substantial 
reduction in the sex ratio as a result of differential survival rates of juvenile 
and adult birds. Consequently, hunting was responsible for reducing the sex ratio 
by only 45 cocks per 100 hens (63 - 18) rather than 57 cocks per 100 hens (75 - lo). 
These data show that the usual practice of attributing sex ratio changes 
entirely to hunting results in overestimating the proportion of cocks that are 
shot. Our present interpretation of the above data is that (1) 71 percent ( 5/ 3) 
of the cocks available during the hunting season were harvested and (2) the cocks 
that were shot represented about 60 percent (45/75) of the cocks alive during the 
prehunt trapping period. Both of these figures are minimum estimates since no 
attempt was made to account for illegal hen-kill. 
2. Manipulation of Pheasant Habitat **• JOie y 
The chemical defoliate, Ortho Paraquat, has been extensively evaluated in both 
greenhouse and field tests in the United States and other countries. This chemical 
has proved useful as a contact killer of some broadleaf weeds and grasses and as a 
crop desiccant. However, it was the utilization of the chemical in pasture 
renovation that led to its use as an intergral part of minimum tillage operations 
in seeding grasses and legumes on roadsides for nesting pheasants. 
In the early 1950's, agronomists learned that turning the soil prior to 
seeding a crop was not essential to good growth of the crop. When existing ground 
