Vol. 16, No. 9 
Page 3 
Responses of Prairie Chickens to Habitat Manipulation R. L. Westemeier, 
D. R. Vance 
In a preliminary assessment of the nesting season of 1973 (MWRL 16(7) :2), we 
noted a drastic reduction in nest success on the sanctuaries at Bogota. Of the total 
of 83 prairie chicken nests found this summer, 3 were atypical and 6 were of unknown 
fate. Of the remaining 74 nests of known fate, only 23 were successful, 50 were 
destroyed, and 1 was abandoned. The success level of 31-1 percent was the lowest 
recorded in the 11 years of this study. Nest success averaged 66-9 percent (range, 
57*1 to 100.0 percent) during the past 10 years (1963-72). 
Predation accounted for 67*6 percent of the nests of known fate. The 
predation rate for the previous 10-year period averaged 28-5 percent (81 of 284 
nests). Abnormal weather conditions, as discussed in MWRL 16(7):2, are believed 
responsible for this high predation rate; they may also be responsible for a few 
prairie chickens being hatched on private land. Prolonged wet soil conditions 
prevented or delayed most spring plowing and promoted luxuriant growth of pastures. 
As a result, much more nest cover was available on private land than in past years. 
We can not accurately evaluate the effect of this abnormal nesting season on the 
population level of prairie chickens at Bogota until the booming-ground census 
in the spring. 
