No. 40. 



NOETH AMEEICAN FAUNA. June, 1916. 



A SYSTEMATIC ACCOUNT OF THE 

 PRAIRIE-DOGS. 



By N. HOLLISTER. 



INTRODUCTION 



The prairie-dog is a true ground squirrel, or spermophile, and its 

 common designation ''dog" is most unfortunate from the standpoint 

 of exact science. The name is now so generally used, however, that 

 any attempt to substitute one more appropriate would be futile. 

 The animals may be conveniently divided into two general classes — 

 the black-tailed prairie-dogs (subgenus Cynomys, three forms of 

 two species) and the white-tailed prairie-dogs (subgenus Leuco- 

 crossuromys, four forms of three species). 



DISTRIBUTION, HABITS, AND ECOXOMIC RELATIONS. 



Early explorers of the Western States were much impressed by 

 the peculiar habits of the prairie-dog, one of the most abimdant and 

 conspicuous mammals over much of what was then ''Louisiana" 

 and the region of the upper Missouri Eiver. Their journals and 

 narratives contain numerous references to this spermophile under 

 such names as prairie-dog, petit chien, wishtonwish, barking squirrel, 

 and prairie squirrel, together with long accounts of the "dog-towns" 

 and the social habits and notes of alarm of the animals. As usual 

 in the case of a new and interesting animal, these accounts are partly 

 true and partly erroneous, having been drawn from actual obser- 

 vation supplemented by stories of travelers, settlers, and Indians. 



Prairie-dogs are distributed over a large part of the Great Plains 

 and Rocky Mountain regions of the United States and southward 

 into northern Mexico. This actual area is relatively small, however; 

 the animals are found in no other region. Though the several forms 

 are constantly extending their ra,nges into new valleys and pushing 

 out into new pastures on the plains, the animal has penetrated into 

 only a small area of the Great Basin, and seems sharply restricted by 

 its specialized nature from occupying any great part of the humid 

 eastern plains, the northern prairies of Canada, the Tropics, or the 

 immense stretches beyond the Rockies, 



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