Vo I. 9, No. 5 
Page 4 
The process of extinction was espec.ai'y evident at Hookdaie in Bond County 
in 1 966, where five cockr were en on a be ming ground during a late March count, 
but on two mornings in n'u-Apri thi ce to five solitary cocks were up to 1 mile 
or more apart and exhib ted unstable territorial behavior. At Hunt in Jasper 
County in 1 966 , no chickeuo were seen on the 4-square~miIe area that was first 
censused by Dr. Ralph E. Veatter in 1936 (Table 3), but one cock, with two hens, 
was seen about £ mile from the east edge of this area. 
There is good reason to believe that the 13 percent dec 1 ine shown for Bogota 
in I 966 (Table 3) is not the true situation. The peak count of 47 cocks in 1 965 
was made iring a period when counts were declining on one booming ground and 
increasing on another ground, and duplications in the high count probably occurred. 
The average for 12 counts made between mid-February and late April, 1 965 » was 34.0 
cocks, but during the same period in 1966, the average for 20 counts was 37-8 
cocks. Also, the number of cocks on the booming grounds showed a greater degree 
of stability in 1 966 than in 1965- These data cast strong doubt that a population 
decline actually occurred at Bogota between 1965 and I 96 S. Hopefully, this is the 
first indication that management activities at Bogota are becoming effective in 
the preservation of prairie chickens there. 
Table 3- High counts of prairie chickens on booming grounds on 10 census areas in 
south-central Illinois, 1963-66. Numbers in parentheses indicate additional birds 
found subsequent to 1963 within 1 mile of, but not in, the 1963 census areas. 
Cocks £• Hens* 
Cocks Only 
Percent Chanqe 
Census Area 
1963 
1964 
1965 
1966 
1965-66 
Jasper Co. 
Bogota 
89 
65 
47 
41 
-13 
West Liberty 
10 
5 
7 
5 
-29 
Hunt 
4 
10 
(7) 
3 
( 6 ) 
0 
( 1 ) 
-100 
Wayne Co. 
Mt. Erie 
45 
48 
31 
18 
-42 
C i sne 
23 
7 
C7) 
0 
(15) 
6 
(3) 
+600 
Marion Co. 
Farina 
33 
27 
( 6 ) 
29 
( 11 ) 
23 
( 10 ) 
-21 
Clark Co. 
Martinsv i 1 1 e 
29 
23 
( 6 ) 
14 
(3) 
6 
( 2 ) 
-57 
Bond Co. 
Hookda1e 
18 
16 
13 
5 
-62 
Effingham Co. 
D i eterich 
14 
10 
2 
0 
-100 
Clay Co. 
Xen ia 
23 
16 
2 
0 
-100 
A 1 1 Areas 
310 
111 
(36) 
! 48 
135) 
loll 
(16) 
-30 
* Mostly cocks. 
