INTRODUCTION 



MAMMALS characteristically are warm-blooded animals 

 that have backbones, are at least partly covered with hair 

 of some kind during their lives, possess mammary (milk) 

 glands, and give birth to living young. Any animal occurring 

 wild in Illinois and having four limbs and a coat of fur or hair 

 is easily recognized as a mammal. 



In addition to man and his domesticated animals, 59 species 

 of mammals are known to occur in Illinois. Of these species, 

 three — roof rat, Norway rat, and house mouse — were intro- 

 duced from the Old World. The others are native. The com- 

 monest Illinois mammals are mice, shrews, rabbits, and squir- 

 rels. Larger mammals, such as beavers, badgers, and deer, are 

 less abundant. Bison, elk, bears, wolves, mountain lions, and 

 some other mammals that once roamed the prairies or lived in 

 the forests of the Illinois area have vanished from the state, or 

 are present only as caged animals. 



In pioneer days, many wild mammals served as sources of 

 food and clothing for settlers and as means of livelihood for 

 trappers. Although they are no longer of paramount impor- 

 tance in this respect, the wild mammals of Illinois today continue 

 to be a significant asset. The furbearers, such as muskrats, 

 minks, and foxes, have yielded annually more than a million 

 dollars worth of fur. The game animals, such as rabbits and 

 squirrels, have provided millions of pounds of food each year. 

 Also, some of the wild mammals are a source of welcome recre- 

 ation to hunters and naturalists. 



WHERE MAMMALS LIVE 



The casual observer or the average hiker sees very few wild 

 mammals out-of-doors and he may get the impression that they 

 are a rarity. Actually, mammals are numerous in almost every 

 acre of uncultivated land in Illinois — prairie, forest, meadow, 

 fencerow, and marsh — probably 5 to 12 times as numerous as 

 birds. In woods there may be 10 to 60 mammals per acre; in 

 a meadow, along fencerows, and in grassy places along forest 



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