492 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 5 



acorns, nuts, buds and seeds, especially of most important wooded areas of this type 



elms and maples, and Osage orange fruits. are along the Mississippi, Illinois, Ohio, 



Water is supplied by streams and ditches Wabash, Rock, Kaskaskia, Embarrass, Big 



and probably by such succulent foods as Muddy and Cache rivers and aggregate 



berries and green corn. The fox squirrel more than 2,250,000 acres (Case & Myers 



Fig. 16. — The cypress or cypress-tupelo gum type in the extreme southern tip of Illinois is 

 fair squirrel range. Foods offered by this type are cypress seeds and tupelo gum drupes. Shown 

 here is a tupelo gum bottom, Massac County. 



exclusively is found in the black prairie, 

 except in towns and in a few heavily wood- 

 ed and ungrazed bottoms. Fig. 14 il- 

 lustrates this type. 



Woodland Habitats 



The term woodland, as used here, de- 

 notes squirrel habitats other than the 

 woodlot types found on the black prairie. 

 The Illinois woodland habitats contain a 

 vastly larger total wooded area, as well 

 as much larger wooded tracts, than the 

 black prairie. A rough distinction be- 

 tween the two types of squirrel habitat is 

 that black prairie woodlots are surrounded 

 by fields, while woodland range is only 

 irregularly broken by cultivated fields or 

 other open land. Woodland habitats, for 

 convenience, may be divided into two 

 main subtypes : the river bluffs and bottoms 

 and the wooded upland. 



River BluflFs and Bottoms.— Con- 

 stituting this type are the bottoms and 

 contiguous bluffs of the various river sys- 

 tems bordering and within Illinois. The 



1934). The variety of trees and shrubs 

 on this extensive area is great. The prin- 

 cipal bottomland trees in the northern half 

 of the state are elms and maples, and in 

 the southern half these species plus oak, 

 hickory and pecan ; cypress and tupelo gum 

 swamps are found in a few wet bottoms 

 in extreme southern Illinois. The bluffs 

 in all cases support oaks and hickories, with 

 walnut occurring in many localities. 

 Shrubs are of wide variety and may be con- 

 sidered an important part of the cover. 



A bottomland habitat in central Illinois 

 is illustrated in fig. 15. A southern Illi- 

 nois habitat, principally tupelo gum, is 

 shown in fig. 16. 



The river bluffs and bottoms type is 

 found in Illinois in varying densities and 

 stages of maturity. Grazing is the rule, 

 as in black prairie woodlots, but not many 

 of the bottomland areas are seriously in- 

 jured as squirrel range by this practice. 

 Den trees are generally ample, but ex- 

 tensive lumbering is now seriously re- 

 ducing both the number of den trees and 

 the number of areas containing such trees. , 



