Vol. 1, No, 4 
W Page 4 
Table 1. Results of censuses of prairie chickens on booming grounds on areas in 
southern Illinois during early April of 1963 and 1964, 
Location of Area 
1963 
1964 
Bond Co.; near Hookdale 
18 
19 
Clark Co.; near Martinsville 
29 
32 
Clay Co.; near Xenia 
25 
19 
Effingham Co.; near Deterich 
14 
11 
Jasper Co.; near Bogota 
89 
74 
Jasper Co.; near W. Liberty 
10 
5 
Jasper Co.; near Hunt 
— 
17 
Marion Co.; near Kinmundy 
53 
33 
Perry Co.; near Swanwick 
5 
2 
Wayne Co.; near Cisne 
23 
20 
Wayne Co.; near Mt. Erie 
45 
58 
Totals 
ITT 
290 
* Not censused in 1963• 
5. Rabbit Management 
W. R. Edwards, D. A. Casteel 
Trapping of cottontails on the two Allerton Park study areas from February 25 
to March 5; 1964, resulted in the color-marking of 32 rabbits on the 4-H Area and 
12 on the Sanctuary Area. Dr. H. H. Shoemaker and students from the University of 
Illinois cooperated in the annual spring census on these areas. The purpose of the 
census was to obtain a population estimate based on the ratio of marked:unmarked 
cottontails observed on a series of coordinated drives covering the study areas. 
This was the seventh spring census on the Sanctuary Area and the eighth on the 
4-H Area, Eight of the 39 rabbits tallied on the Sanctuary Area in the 1964 spring 
census had been marked during the recent trapping; and 25 of the 43 rabbits counted 
on the 4-H Area had recently been marked. On the basis of the data obtained from 
trapping and from the drive censuses, population estimates were computed for the 
two areas, using the Petersen-Lincoln Index: 
N = 
7T 
n 
m 
thus N = Mn 
m 
with the standard error of the estima te determi ned by 
M^n (n-M) 
m- 
where N 
M 
n 
m 
the estimated population 
the number of marked animals in the population 
the observed sample 
the number of marked animals in the observed sample, 
Thus, the estimated numbers of cottontails on the Allerton Park study areas in 
:he spring of 1964 were 58+7 for the 4-H Area and 55 + 17 for the Sanctuary Area. 
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