FIELD BOOK OF MAMMALS 



parts varying from soiled whitish to rusty ochraceous; feet 

 plain ochraceous." (Bailey) Total length, 20 inches; tail 

 vertebrae, 9 inches; hind foot, 2.6 inches. Found in the 

 Mogollon Mountains of New Mexico. 



The Ground Squirrels of the genus Otospermophilus might 

 be easily mistaken for Gray Squirrels (genus Sciurus) at first 

 glance, but can be distinguished by their less busy tail and 

 spotted or faintly mottled pelage. Furthermore, they run 

 into holes in the ground, and if up a tree when danger ap- 

 proaches get down to the ground as soon as possible. They 

 climb trees to a limited extent, but do not usually go very 

 high. Not infrequently one will climb up a few feet to sun 

 itself, or watch from the top of a stump or a tall stub. 



These Squirrels haunt semi-open country in the northern 

 parts of their range where they may be found in clearings, 

 about overgrown fields or wherever brush and logs give good 

 cover. Farther south they may occur in open forest or on 

 rocky hillsides and shrub-covered slopes. In some sections 

 they are known as Rock Squirrels because of their fondness 

 for cliffs and rock masses. The members of this genus have 

 rather a wide altitudinal range and live from plains at sea- 

 level up to 8,000 feet elevation or higher. 



In general, the habits of Otospermophilus are those of the 

 genus Citellus, see page 213. These animals are very injurious 

 to crops in settled districts and have still other claims upon 

 the attention of man because some species, notably the Cali- 

 fornia Ground Squirrel, serve as host for the flea which carries 

 the bubonic plague. They store up food for periods of bad 

 weather, become very fat toward the close of summer, and 

 hiijernate in the colder parts of their range. 



The call-note of Otospermophilus is usually a single, loud 

 whistle, but sometimes it utters a series of whistles in a de- 

 scending scale. These Squirrels are strictly diurnal as are 

 all our Ground Squirrels. 



Genus Callospermophilus 



Dentition: Incisors, {-Canines, % ; Premolars, f ; Molars, | = 22. 



196 



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