ANTELOPE GROUND SQUIRREL 



striped pelage. The call-note is a long trilling whistle quite 

 unlike the loud, single chirp or yelp of so many of the species 

 of Citellus. Members of this group have long periods of 

 hibernation, in the northern part of the range six months or 

 more. 



Where Ground Squirrels come into contact with agricul- 

 ture they may, and generally do, become an economic prob- 

 lem. Because of their abundance and their fecundity, the 

 rancher or farmer must have recourse to poison, traps, and 

 guns to protect the crops. The number of young in a family 

 of Citellus may vary from five to as many as thirteen or four- 

 teen. Most of the species of Citellus raise but one family a 

 year; possibly this holds true for all of the North American 

 species. Wherever there is any extended period of hiberna- 

 tion, a second litter of young would not have time to store up 

 fat for the long sleep. 



Ground Squirrels store up food in their burrows, which is 

 used as emergency rations in the spring before other food is 

 available and probably for a short time after they enter the 

 winter den in the fall. 



Genus Ammospermophilus 



Dentition: Incisors, \; Canines, ^ ; Premolars, f ; Molars, I = 22. 



Antelope Ground Squirrel. — Ammospermophilus 

 leucurus and related forms 



Names. — Antelope Ground Squirrel; Antelope Squirrel; 

 Antelope Chipmunk; White-tailed Chipmunk, Plate XXIII. 



General Description. — A small, terrestrial Squirrel, slightly 

 larger than an Eastern Chipmunk, having a' single, longi- 

 tudinal, white stripe down each side; tail short, narrow, flat, 

 and carried turned up over the back when running; ears 

 rather small. 



Color. — Sexes colored alike; seasonal variation slight, 

 summer pelages somewhat brighter than winter. 



Upperparts. — Mixed dark brown and vinaceous cinnamon 

 or finely grizzled with whitish or yellowish, grayest on neck to 

 mid-back, brownest on crown, rump, and outer sides of 

 Hmbs; pelage blackish at base; a single, well-defined, white 

 stripe on each side from shoulder to rump and separated from 



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