Vol. 6, No. 8 
Page 2 
percent (431 eggs) of the eggs examined were fertile (contained embryos) and 6.1 
percent (28 eggs) were infertile (lacked embryos). Table 1. Of the 431 embryos 
examined 96.3 percent (415) were alive and 3*7 percent (16) were dead. Therefore, 
of the 459 eggs examined during the 3 years, 90.4 percent (415) could have pro¬ 
duced chicks. These findings, similar to those that have been reported for phea¬ 
sants in self-maintaining populations, tentatively suggest that the frequency of 
infertile eggs and dead embryos did not suppress the establishment of pheasants on 
the Neoga study area. 
Table 1. Percentage fertility of pheasant eggs produced on the Neoga area in 
1961, 1962, and 1963, as determined by the presence or absence of embryos. Num¬ 
bers of eggs are in parentheses. 
Year 
Numbers of 
Eggs Examined 
Percent of Eggs 
Containing Embryos 
Percent of Eggs 
Lacking Embryos 
1961 
106 
99*1 (105) 
0.9 < 0 
1962 
181 
90.6 (164) 
9*4 (17) 
1963 
172 
94.2 (162) 
5.8 ( 10 ) 
All years 
459 
93*9 (431) 
6.1 (28) 
4. Responses of Bobwhites and Prairie Chickens J. A. Ellis, 
to Habitat Manipulation R. J. Ellis 
Eighty-one individual quails (74 cocks and 7 hens) were captured in cock-hen 
traps, marked, and released on the 16-square mile Bogota area during the spring 
and summer of 1963* Also, marked cocks were recaptured a total of 76 times during 
this same period. Three hundred ninety-eight "trap-days' 1 were expended to capture 
the 157 quails, a rate of 39*4 quails per 100 trap-days. 
Weights of 127 cock quails captured on the Bogota area during May, June, and 
July, 1963, ranged from 145 grams to l90 grams with an average of 171*1 +0.9 
grams. Recaptured quails were not weighed if they had been weighed during the 
preceding 7 days. Seven hen quails ranged in weight from 185 grams to 220 grams 
with an average of 195*0 + 3*4 grams. 
5. Rabbit Management W. R. Edwards, 0. A. Casteel 
It has been demonstrated that age ratios varied among populations of cotton¬ 
tails. Seasonal aspects of rabbit production were analyzed for trends which could 
explain differences in age structure. The variance of cottontail ages was fairly 
similar for all areas. The samples with higher proportions of juveniles also had 
higher coefficients of variation of birth dates. Generally, this indicates that 
high age ratios result when young rabbits born throughout the entire reproductive 
season are well represented in the fall population. Conversely, a low age vari¬ 
ance results when only a few cottontails born during a particular period survive 
unti1 fall. 
There was a slightly earlier average birth date for juvenile cottontails 
