508 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 5 



noted that the squirrel population was lim- 

 ited to the former species. This situation 

 was encountered on certain Mississippi 

 River bottoms where pin oaks supply the 

 main food resource; in the sand region of 

 Mason and Cass counties, where black oak 

 supplies the main food staple ; and on farm 

 regions throughout the state, where corn 

 is the basis of subsistence. Food, however, 

 is only one criterion for defining the pre- 

 ferred range of the two species. The 

 range appears to be determined by the 

 combination of food, cover, water and pos- 

 sibly space. 



In the course of field work it was noted 



many times that both species of squirrels, 

 even in regions abundantly supplied with 

 food, made limited use of acorns, walnuts, 

 hickory nuts, Osage orange fruits and 

 similar items while they were still quite 

 green. What this use represented — mere- 

 ly a sampling, the activity of juvenile 

 squirrels, an attempt to obtain water — was 

 not ascertained. 



Storing and Feeding Habits 



Storing or caching appears to be in- 

 stinctive in squirrels; juveniles are among 

 the first to begin this activity in the fall. 



Fig. 29. — Fox squirrel feeding in characteristic manner — sitting on hind legs with nut 

 grasped between forepaws. (Photo by Gordon S. Pearsall.) 



