Vol. 10, No. 11 
Page 3 
Area. Forty-six percent of the 13 nests located at Bogota in 1 967 hatched. In the 
past five summers, 1963-67, hatch success has averaged 41 percent (based on 99 nests 
of known fate). Thus, hatch success was slightly above average in I967. Only one 
nest was known to have been destroyed by plowing in 1967 , but the 46 percent loss of 
nests due to predation was the highest since I 963 . 
The average number of eggs in nine completed clutches in 1967 was 11. 3 . An 
average of 10.4 eggs per completed clutch was calculated for 56 clutches for the 
TnAot I 963 ' 67 ' ^P^tive fertility and hatchability levels amounted to 94-5 percent 
Ah?i^‘ 2 i Per ? e r t e " S ‘ n S ' X c,utche s Bogota in 1967. The average hatch- 
ability level for 372 eggs in 35 clutches during the perico 1963-67 was 55.7 percent. 
Seventeen dates of hatch were established from data on seven nests and from age 
estimates for 10 prairie chicken broods. The dates of hatching in 1367 extended from 
ay 18 t° Ju y I, with 50 percent of hatching completed by June 3 . Midpoints of 
hatching in 1966, 1964, and 1 963 were estimated to be June 7, Mav 27, and June 2 
respectively. ’ 1 
The average size of five broods observed in I3S7 (three in Jasper Count/ and two 
l'Q67 a 9,° n T S 7 ' 6 ch,cks ' Complete counts of brood size were too limited in 
I frL ! UPP a , '!! ef ! nces ab0Ut the 9radua ' attrition of brood size. One of possibly 
contained'1 I n seen on the newly acquired 160-acre sanctuary in Marion County 
contained 11 young prairie chickens approximately 8 weeks of age. 
6• Rabbit Management 
J. A. 3ailey, J. C. Hanson 
p. r , ca P tur,n S cottontails during September through March on the Allerton 
4 ’k- been pos» tively correlated with weather conditions which orevaii 
within high-pressure air masses (Monthly Wildlife Research Letter 10(10)-4)*. However 
with respect to weather, the trap responses of adult male rabbits were conspicuously ' 
mo re ITJaZ d °*" A r C ' a “ eS - °‘her rabbits bocal * 
more trappable dur.ng cool periods with high atmospheric pressure, little wind and 
no precipitation the trappabiiity of adult males was not correlated with wind! showed 
positive correlation with the occurrence of precipitation fr = C.25,' n 0.01) and 
! a550Ci rt d wi f h low midnight barometer reading and Ln 
HrrllL trapping adult males was analyzed by multiple regression, with midnight 
indent read "?9> w,no > occurrence of precipitation, and minimum temoereture as 
independent variables, only one partial regression coefficient was significant. 
tiabo[na a <PC0 n? , re adult h males were captured when precipitation occurred during 
trapping (P<0.01) than when precipitation did not occur. 
Iran hnunln^K faC 5° rS influencin 9 the probability that a cottontail will enter a box 
of ho^e ran determined. Susceptibility to trapping could be influenced by size 
of home range, amount of movement, wariness, curiosity, an inclination to seek shelter 
traonLm £><pa ™ w ‘ th The roies of these and other factors in determiner 
we cannol e V f !' ary 1 . w ‘ th weather. Since we do not know why rabbits enter traps, ' 
we cannot explain why the trap responses of adult male cottontails on the 4-H Area 
sex-age'classes^ '° Weathar ' been diametrically opposed to responses of the other 
