Vol. 25, No. *4 
Page 3 
> 
1 
Sex 
Age 
Leaf 
Nest 
Number found in 
Nest Box 
Tree 
Cavity 
Area A 
Area B 
Area A 
Area B 
Area A 
Area B 
Male 
Subadult 
2 
3 
Absent 
*4 
8 
0 
Yearling-adult 
8 
5 
It 
20 
13 
1*4 
Totals 
10 
3 
2*4 
21 
1*4 
Female 
Subadult 
1 
0 
Absent 
1 
*4 
3 
Yearling-adult 
anestrous 
3 
1 
11 
2 
0 
3 
Yearling-adult 
estrous 
5 
7 
11 
2 
13 
10 
Totals 
9 
8 
£ 
17 
16 
-Total females significantly less (£ < 0.01) abundant in nest boxes than males. 
Responses of Prairie Chickens to Habitat Manipulation - W-66-R R.L. Westemeier, 
- c - J.E. Buhnerkempe 
This spring prairie chickens were censused for the 20th consecutive year 
near Bogota in Jasper County, near Kinmundy in Marion County, and near Mt. Erie 
in Wayne County. The count near Hoyleton in Washington County was begun in 1969- 
These *4 areas were the only known sites in 1981 still harboring native remnants 
of the millions of pinnated grouse once distributed over at least two-thirds of 
Illinois. 
Near Kinmundy, the prairie chicken population increased 32%, from 88 cocks 
in 1981 to 116 cocks this spring. Although sanctuary area near Kinmundy (1*46 ha 
[361 acres]) was less than near Bogota (*405 ha [1,001 acres]), the distribution 
of booming grounds (leks) was more favorable for chickens. Leks extended from 
just south of Farina to just east of Brubaker--a distance of 1*4.*4 km (9 mi). 
Chicken numbers were high on or near each of the 5 sanctuaries and the sex ratio 
appeared to be good. For example, the lek on the Illinois Natural History Survey 
Sanctuary showed a high count of 20 cocks and 23 hens on *4 April, a higher count 
of hens than for any lek at Bogota. 
The Bogota flock increased 19%, from 70 cocks in 1981 to 83 cocks this 
spring. We had predicted 82. *4 + 15-0 cocks (MWRL 2*4 (8): 3) on the basis of the 
number of hatched nests found at Bogota in 1981. Considering recent cyclic highs 
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