HOFFMEISTER & MOHR: ILLINOIS MAMMALS 



21 



ally beat trails through dense vegetation, fig. 13, especially in 

 the vicinity of their burrows. Voles make distinctive trails 

 through grass; these trails frequently are exposed by grass fires 

 in spring, fig. 14. Muskrats and minks in swimming through 



Fig. 11. — Top, lodge of muskrat; bottom, lodge of beaver. 



duckweed beds leave open-water trails which generally are 

 longer than those left by fish feeding at the surface. Most mam- 

 mals, however, use trails common to several species, or use ave- 

 nues of travel not recognizable as definite trails. For example, 

 a stream edge may exhibit many tracks of raccoons, opossums, 

 and minks, indicating a great deal of night traffic but no well- 

 defined land trail. A forest edge may serve as an avenue oi 

 travel by many species, although it may have no signs to identify 

 it as a trail. 



