Vol. 8, No. 4 
Page 4 
4. Responses of Bobwhi tes to Habitat Manipu 1 at ion 
J. A. Ellis, R. L. Westemeier 
Posthunt censuses of quail in January I 965 produced population estimates of 
116, 147, and 57 birds on the Dale, Forbes, and Alma areas, respectively (Table 3)• 
The posthunt population on Dale in 1965 was estimated to be 24 percent greater 
than in 1964, but on Forbes was estimated to be 27 percent smaller. 
The prebreeding populations were estimated to be 42, 74, and 88 birds on the 
Dale, Forbes, and Alma areas, respectively, in March 1965- These estimates were 
smaller than those obtained on the areas in March 1964 and represented declines 
of 9 percent, 37 percent, and 12 percent on the Dale, Forbes, and Alma areas, 
respectively. 
Losses in the quail populations from January to March were greater on the Dale 
and Forbes areas in 1965 than in 1964 (Table 3). and could be attributed to (1) 
more emigration from the areas, (2) more adverse weather, and (3) greater habitat 
deterioration in 1965 than occurred in 1964. 
Table 3- Population estimates of quail, obtained from censuses on the Dale, Forbes, 
and Alma areas in January (posthunt) and March (prebreeding) of 1964 and 1965 - 
Area 
January 
(Posthunt) 
March 
(Prebreed 
inq) 
Percent change from 
January to March 
1964 1965 
1964 
1965 
1964 
1965 
Dale 
88 116 
46 
42 
-48 
-64 
Forbes 
202 147 
117 
74 
-42 
-50 
Alma 
57 
100 
88 
+54 
5. Responses 
of Prairie Chickens 
to Habitat Manipulation 
R. 
J. El 1 is 
The annual census of prairie chickens on booming grounds on 10 selected areas 
in southern Illinois was conducted during the first 2 weeks of April, 1964 and 
1965 (Table 4). Three or more counts were made on each area and the count which 
included the largest number of cocks was taken as the census figure. All counts 
were made during the first hour of daylight. 
In 1964, 288 prairie chickens (252 cocks and 36 hens) were counted on 34 
booming grounds found on the census areas. In I 965 , 20 booming grounds were found 
on the census areas and 1 89 prairie chickens (163 cocks and 26 hens) were counted. 
These data indicate a 35 percent reduction of prairie chicken numbers on the census 
areas from 1964 to I 965 . In 1964, the data indicated a 19 percent reduction of 
prairie chicken numbers on the census areas from 1 963 to 1964 (Monthly Wildlife 
Research Letter , April, 1964). No wi1dlife popu1 at ion , especia 11y one as sma11 
as most prairie chicken flocks in Illinois, can long sustain such large annual 
losses. 
If prairie chickens are to be preserved in Illinois, it is absolutely imperative 
that substantial measures be taken in 1965 to curb the large annual population 
