Vol. 18, No. 8 
Page 6 
In summary, supplemental feeding during the winter of 1974-75 did not result 
in substantial benefits for squirrels on the experimental area. There was a 
significantly (P-0.05) lower frequency of mange on the experimental area and a 
higher capture of new animals on the area with supplemental feed than on the 
control area ( 51-6 vs 35.7 squirrels captured per thousand trap nights, respect¬ 
ively). The number of captures per thousand trap nights and changes in this 
index between December and April were similar on the two areas, although the 
actual number of squirrels captured was higher on the experimental area in both 
December and April. Reproduction was high on both areas--the majority of mature 
females captured had spring litters. The average weights of adult fox squirrels 
were higher on the control area than on the experimental area in both December 
and April. Significant weight losses occurred in both male and female fox 
squirrels on the experimental area between December and April. Although fewer 
gray squirrels were caught than fox, the gray squirrels had more stable body 
weights on the experimental area from December to April than the fox squirrels. 
Responses o£ Prairie Chickens to Habitat Manipulation 
R. L. Westemeier, 
D. R. Vance 
For the third consecutive year, nest success on the sanctuaries at Boqota 
was below 50 percent. Of the 58 nests found this summer, 5 ( 8.6 percent) were 
abandoned, 2 y (50 percent) were destroyed, and 24 (41.4 percent) were successful. 
Hatch success in 1975 was essentially unchanged from 1 974 (40-7 percent) despite 
much more favorable weather conditions during the spring and summer of I 975 . 
Although hatch success in 1975 showed little improvement over that of 1974 
there were promising signs. The number of fertile eggs per clutch was unchanged, 
but the number of hatched eggs per clutch increased from 8.9 to 9.6 and hatch- 
ability increased from 82-3 percent to 93-0 percent. These increases resulted 
in more chicks being produced from the same number of successful nests. 
Also, hen kills occurred 
decrease from 10-3 percent to 
the mean of 12.1 percent over 
at only 1 of the 29 destroyed nests this year, a 
3*4 percent. This rate of kill is much lower than 
the previous 12-year period. 
It is hoped that these small improvements, 
conditions this summer, mark at least a slowing 
past 2 years. 
plus the excellent brood-rearing 
of the population decline of the 
l) 
