GE()(JKArillCAL DISTRIBUTION OF MAMMAI.S. 



423 



An exaiiiination of the mammalian fauna bears out Dr. Mer- 

 riam s conclusions, although the lower austral species are not nu- 

 merous. The species typical of the more southern latitudes are the 

 southern shrew {Sorcx longirostris) , Carolinian short-tailed shrew 

 (Blarina brevicauda Caroline nsis) , long-eared bat {Corynorhinus 

 macrotis), large-winged bat {Myotis grisescens) , small shrew (Bla- 

 rina parva), water hare (Lepus aquatic u s) , spotted skunk (Spilo- 

 gale putorius), and water rat (Oryzomys paliistris) , the last being 

 of (juestionable occurrence. 



In the northwestern part of the State a few species that are 

 characteristic of the western prairies, reach the eastern limit of 

 their range. These are the two spermophiles (Citellus tridecem- 

 lincatits and C. fra)tkli}iii) , the pocket gopher (Gconiys hiirsarius) , 

 coyote or prairie wolf (Ca)iis latrans), prairie skunk {Mephitis 

 mcsomclas avia) and the badger {Taxidea ta.rus), the last being 

 now almost extinct. The prairie mouse {Peroniysciis niaiiiculatus 

 bairdi), prairie vole {Micro! us ochrogaster) , and prairie rabbit 

 {Sylvilagus f!orida)ius mcunis'n are also of prairie origin, although 

 they now extend over nearly or quite all of the State. 



Four species, the porcupine {Erethizon dorsatus), the fisher 

 {Mustcla pennanti) , the wolverine {Gulo liiscns) and the star-nosed 

 mole {Condylura cristata) are believed to be of northern origin. 

 The first three of these are also extinct. 



It will thus be seen that the fauna of the State is not character- 

 istic of any zone or faunal area, but that it is rather characterized 

 as an area where the different faunal types blend. In the absence 

 of mountains or other barriers, it is not possible to fix upon definite 

 boundaries of the life zones. 



RELATION TO ENVIRONMENT. 



In their relation to the mammalian fauna, physical features 

 other than climate, have a marked influence. The hilly southern 

 portion of this State is better suited for many species of animals 

 than the more level regions in the central and northern parts, and 

 such animals as rabbits, opossums, weasels, minks and skunks are 

 more abundant. Caves, which are numerous in some counties, 

 afford homes for bats, and these animals are abundant in the cave 

 regions. On the other hand, some mammals, especially two or 

 three species of voles or meadow mice, are inhabitants of damp 

 places and are most abundant amcmg the lakes and swamps in the 

 northern part of the State. 



