Vol. 23, No. 12 
Page 3 
Responses of Prairie Chickens to Hab i tat Nan i pu lat i on -U-ou - R R.L. /estemeier, 
-c-• " J.E. Buhnerkempe 
The importance of hatch success by nesting prairie chickens has been 
discussed in previous reports on the basis of the percentage change in numbers 
of cocks on leks (booming grounds) and the percentage hatch success (MV/P.L 22(9):3* 
23(10):2-3). Significant correlations were found with the use of these parameters; 
however, higher correlation coefficients were revealed by using the spring count 
of cocks (dependent variable) and the number of hatched nests (independent 
variable) found the preceding summer, hatches from a sample of 7 P 1 nests 
(reported nests on private land as well as nests on sanctuaries) versus the cock 
count for the years 1963-80 resulted in the highest coefficient (^ *» 0.9^5; 
P<0.001) among the parameters tested. Thus, the spring population at Bogota 
Vince 1963 has been closely dependent on the number of hatched nests found the 
preceding summer; 893; of the variation in the spring numbers.of cocks on leks 
has been associated with the number of hatches. Lower but highly significant 
coefficients were also found using hatched nests actually examined (1) on 
sanctuaries and private land and (2) on sanctuaries exclusively. The use of 
total nests as the independent variable also resulted in a highly significant 
coefficient (ir ■ 0.322, P<0.001). Thus, although hatch success of about 50% may 
qenerally indicate population stability, this "rule of thumb" may predict 
population change less accurately than other parameters. The best reproductive 
parameter we have for predicting change in the prairie chicken population at 
Bogota appears to be the number of hatched nests. By this measure,we predict 
a decline from 92 cocks in the spring of 19^0 to 63.^ + 15-0 cocks in the 
spring of 1931. 
Fall counts of prairie chicken cocks are also highly predictive of 
subsequent spring population levels (MWRL 23(5) - 3“ • A preliminary prediction 
based on booming ground surveys at Bogota this fall closely agrees with the 
prediction based on the number of hatches. 
We cannot explain why relatively few prairie chicken nests were found during 
the search in 1930. As in the past, the nest search was concentrated on the 
sanctuaries supporting the highest densities of prairie chickens. Also, such 
factors as stability of birds on their leks, hen numbers, and number of 
copulations observed all appeared "normal" in 19 P >0. Apparently a substantial 
number of hens on the Bogota Study Area did not nest. 
Ecoloqy and Management of White-tailed Deer C. M. Nixon, 
-a- =2 ~ l, p. Hansen, 
J. E. Chelsvig 
Personnel working deer check stations for the IS'jO shotgun hunting season 
were provided forms and instructed to record all sightings of marked deer 
by hunters as well as marked deer that were killed and turned in at the check, 
station. Of the 22 marked deer believed to be still alive, k were killed during 
the first season and 2 were killed during the second season (Table l). 
