Vo l. 19, No. 11 
Page 2 
Jr) 
increase in time that was required to bag a pheasant in 1976, compared with 
1975; is indicative of the diminished pheasant population this fall. This 
downward trend would presumably have been greatly accentuated had fall plowing 
been as extensive as in 1975* 
Ecoloqv and Management of Squirrels C. M. Nixon, 
- S. P. Havera 
Twenty-eight fox squirrels were shot during the hunting season of 1975 
from three adjacent large areas of timber in Fayette County in south-central 
Illinois. Fayette County is moderately cultivated, corn, soybeans, and wheat 
being the major crops. Areas of timber and pasture are still common. The 
fox squirrels collected were analyzed for pesticides. 
This sample of squirrels was separated into five groups: adult females 
lactating, adult females not lactating, adult males, subadult females, and 
subadult males. The squirrels were analyzed for DDE, dieldrin, PCB's, and 
other pesticides. 
The concentrations of pesticides found in the specimens were low. Only 
DDE, a residue of DDT, and dieldrin were detected. Only 3 of the 28 individuals 
contained dieldrin, and the range of dieldrin concentrations was 0.0005 to 
0.0023 ppm. However, a surprising number (25) of the 28 specimens contained 
DDE residues. The DDE concentrations ranged from 0.0008 ppm to 0.0195 PP m > 
with an average of 0.0037 ppm for the 25 squirrels in which DDE was detected. 
The highest concentration of DDE was found in the adult female lactating 
group, which had an average value of 0.0053 ppm, whereas the adult female 
nonlactating group had the lowest average concentration, 0.0023 ppm. The 
remaining groups had concentrations approximating the average concentration 
for all squirrels, 0.0037 ppm of DDE. 
The probable method of uptake of DDE and dieldrin by fox squirrels is 
through their diet. Pesticides wash from agricultural fields into small 
creeks and streams. Mast-producing trees probably absorb water containing 
the pesticides. The trees may store the pesticides in their seeds, where 
they become available to squirrels. Considering that the lactating adult 
female group had the highest concentration of DDE, it is possible that 
nursing female squirrels may pass pesticides through their milk to their 
young. DDE and dieldrin are apparently so widespread throughout our 
environment that they even occur in fox squirrels living in areas less 
intensively cultivated than east-central and other parts of Illinois. 
Responses of Prairie Chickens to Habitat Ma nipulation R. L. Westemeier, 
D. R. Vance 
The cash-bid procedure was used in 1975 and 1976 to manage the state- 
owned prairie chicken sanctuaries, which include 567 acres or 36 percent 
of the total sanctuary acreage. Leases were renewed with the same five 
