Vol. 25, No. 9 
Page 3 
Adult male and adult female recruitment rates were higher on those plots 
where adult males and adult females had been removed, respectively, during both 
spring and fall trapping periods (Table 2). During spring, yearling male and 
female recruitment was greatest on female removal plots. During fall, male 
recruitment was highest on male removal plots, whereas female recruitment 
appeared unrelated to adult densities. Both male and female juvenile-subadult 
recruitment were impacted by adult females; recruitment of young, especially 
females, was low where adult females were abundant (Table 2). 
These results indicate that male and female adults may influence recruitment 
in different ways, depending on the sex and age class of potential recruits being 
considered. It is apparent that in unmanipulated populations, potential 
recruitment far exceeds actual recruitment, and that adult female fox squirrels 
most strongly limit recruitment, especially of young. 
Responses of Prairie Chickens to Habitat Manipulation - W-66-R R.L. Westemeier, 
J.E. Buhnerkempe 
For 20 consecutive years we have searched for nests of prairie chickens and 
other grassland fauna in Jasper and Marion counties. Our intensive search in 
1982 revealed 29 prairie chicken nests on 142 ha (351 acres) of sanctuary in 
Jasper County and 19 chicken nests on 49 ha (120 acres) of sanctuary in Marion 
County. Percent nest success was good in both counties, though not as high as in 
1981 (MWRL 24(3):3). In Jasper County, rates of hatch, predation, and abandonment 
were 55.0%, 23.0%, and 17.0%, respectively, for the 29 nests. In Marion County, 
excluding 2 nests of unknown fate and 1 atypical nest with 1 abandoned egg, we 
found 10 hatches (62.5%) and 6 (37-5%) instances of predation. 
The 17% rate of desertion at Bogota was the highest on record for prairie 
chicken nests. Of the 5 deserted nests, 3 nests contained 2, 3, and 10 apparently 
infertile eggs, but 2 other nests, with 14 and 8 eggs, contained we 11-developed 
embryos. Prior to the presence of pheasants in substantial numbers, nest 
abandonment averaged only 3% at Bogota in 1963-68 (MWRL 24(10):3). In Marion 
County, where there are essentially no pheasants, nest desertion by prairie 
chickens has been almost nil in a sample of 52 nests of known fate. Twenty- 
nine of the nests for Marion County were found in 1931-82; the other 23 nests 
date back to 1964. These comparative data for the 2 counties further implicate 
the pheasant as a factor in reduced productivity of prairie chickens at Bogota. 
Three prairie chicken nests were parasitized by pheasants this year; at one, 
the eggs and chicken hen were destroyed by predation, but the other 2 parasitized 
nests had hatched—including the pheasant eggs. Each parasitized chicken nest 
contained at least 3 pheasant eggs. The 10.3% level of parasitism this year 
was well above the average of 3*3% for 1 969 - 8 1. 
Another alarming trend, evidently due to pheasant harassment, was a steady 
decline in hatched chicken eggs per clutch-~from 11.1 in 1963“63 to 8.8 in 1981. 
This summer, however, hatchability rose sharply to an above-average mean of 11.6 
hatched eggs per successful nest. 
