I 
MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
MAY 5 1975 
library 
Urbana, Illinois 
April, 1975 
Vol. 18, No. 4 
Ecology and Management of Sguirrels C. M. Nixon, 
S. P. Havera 
Intermediate cutting, featuring the cutting of individual trees or a small 
group of trees, is used to remove mature to overmature trees, to improve species 
composition and spacing, and to release younger trees for future growth. Inter¬ 
mediate cutting is used throughout Illinois on many timber stands each year, 
yet little is known about the effects of this timber cutting on forest wildlife. 
Squirrels, because of their dependence on large mast-producing trees for food 
and shelter, may be particularly affected by this practice. 
We have been monitoring the response of the squirrel populations to inter¬ 
mediate cutting on two areas in the Shawnee National Forest in Page County, Illinois. 
We livetrap and tag squirrels prior to and for 2 years after the timber cutting. 
The Massac Tower Sale, 44 acres in size, was cut during the summer and fall 
of 1973• A total of 761 trees were marked for sale, and 647 (85*0 percent) 
were trees capable of producing food for squirrels. This represents a removal 
rate of 14.7 trees per acre, all of them large dominant trees. 
All den sites observable from the ground were tallied on the area prior 
to cutting. A similar count was conducted after cutting was completed. There 
were 87 possible nest cavities and 100 escape-only cavities prior to cutting. 
After cutting, only 48 nest cavities (a 44.8 percent decline) were found on 
the area. Only 6 of the 100 escape dens found prior to cutting were removed 
by the timber sale. 
Nest dens were not particularly abundant on the Massac area (1.9 per acre) 
prior to cutting, and nearly half were removed in the timber harvest. Many of 
the escape cavities were at ground level and probably resulted from fires. 
Responses of Pra1rie Chickens to Habitat Manipulation R. L. Westemeier, 
D. R. Vance 
This spring (1975)^ as in past springs, booming ground surveys were con¬ 
ducted along with supplementary observations made by visitors in blinds at 
Bogota almost daily from 22 March through 20 April. 
The peak count for each booming ground this spring revealed a total of 
102 cocks on the Bogota Area, a decline of 28.7 percent from the peak count 
of 143 cocks in the spring of 1974. This was the second consecutive decline 
