Vol. 17, No. 9 
Page 3 
2 were atypical (single eggs in a definite bowl). Of the remaining 59 nests of 
known fate, 40.7 percent were successful and 57.6 percent were destroyed by 
predators. Nest success in 1973 was 31.1 percent, the lowest recorded In the 11 
years of this study; nest success for the preceding 10 years (1 963 - 72 ) averaged 
66.6 percent and no year was lower than 50 percent. 
Although hatch success in 1974 was improved over 1973, the number of fertile 
eggs per clutch ( 9 * 6 ), the number of hatched eggs per clutch ( 8 . 9 ), and hatcha** 
bility (82.3 percent) were all below similar statistics for both 1973 and the 
long-term means for 1963-74. Because of the low hatchability of eggs, fewer 
chicks left 24 hatched nests found in 1974 than left 23 hatches found in 1973. 
In 1974, hen kills occurred at 10.3 percent (4) of the nests that were 
unsuccessful due to predation or abandonment. Over the 12-year period, 1 963 - 74 , 
nest sites showing evidence of hen kills averaged 12.1 percent of 1 99 nests that 
were destroyed by predators or abandoned. 
Probably the most practical management implication to be emphasized by the 
past 2 years of poor nest success is the problem of minimizing predator habitat. 
Denning sites in particular should be eliminated wherever possible on the prairie 
chicken sanctuaries. We hope that the high rate of predation to which nests 
have been subjected the past 2 years is a temporary phenomenon due largely to 
the exceedingly wet nesting seasons. 
