Vol. 7, No. 12 
Page 4 
Table 3- Land use on 10 prairie chicken census areas in Illinois, 1963 and 1964, 
expressed as percentage of total area. 
1963 
1964 
Row Crops 
62.5 
74.3 
Soybeans 
n .7 
13.7 
Legume Hay 
2.3 
l .6 
Legumes* 
• 9 
.6 
Grass Hay 
2.3 
2.0 
Grass* 
4.2 
3-6 
Grass Pasture 
9.2 
6.7 
Weeds* 
• 3 
1 .4 
Trees and Brush 
4.4 
3-4 
Other Uses 
2.2 
2.7 
100.0 
100.0 
* Idle fields. 
Yeatter, Ralph E. 1963* Population responses of prairie chickens to land-use 
changes in Illinois. J. Wildl. Mgmt. 27(4) :739-757- 
6. Rabbit Management J. A. Bailey 
Fifty-eight cottontail rabbits were livetrapped during the first 10 days of 
November 1964 on the Allerton Park 4-H Area. Of these, 3' had previously been 
captured and released on the area during September and/or October. Eighteen of 
the 27 rabbits captured for the first time during November were thought to be new 
immigrants onto the 4-H Area. Animals were designated as immigrants if they had 
not been caught on the 4-H Area prior to November and if their location of first- 
capture during November was along the west or north edges of the area. Corn was 
being picked and land was being plowed to the north and west of the 4-H Area in 
late October and early November. Movement of rabbits onto the 4-H Area was there¬ 
fore expected. 
The weight and total length of each animal were recorded. Total length is 
obtained by grasping a rabbit by the neck and hind legs, extending the animal, and 
measuring from the tip of the nose to the tip of the hind feet. It is thought that 
the physical condition of rabbits can be evaluated by comparing body weights of 
animals having the same total length. Accordingly, the weights and total lengths 
of the 31 known-residents and 18 suspected-immigrants were compared (Fig. 1). Thes 
data indicate that cottontails which moved onto the 4-H Area from adjacent fields 
being harvested and plowed were in poorer physical condition than the rabbits 
already present on the area. The poorer physical condition of the immigrating 
animals could have been the result of inadequate food on the farmed land or the 
effect of other stresses caused by the destruction of the animals' habitat. 
The mortality rate of these two groups of rabbits is currently being studied. 
