i86 



MAMMALS OF AMERICA 



impossible to distinguish it from an old picket-pin 

 or fence stake. Standing thus the animal will 

 often allow one to approach within a few yards, 

 then quickly dropping on all four:, it utters a 

 shrill chatter and dives into a hole close by. 

 Remain quiet for a few minutes and its head 

 reappears at the entrance of the hole, and the 

 little black eyes peer at you curiously, ^^'alk 

 away from the place and it will soon come out 

 and, standing up again, watch you as long as 

 you are within sight, uttering an occasional note 

 of alarm or warning to its friends." 



Usually the Striped Spermophile is con- 

 fined to the sagebush plains and the prairies, 

 although it occasionally works up into altitudes 

 of yoGO feet. This is also a form which shuns 

 woodland of any greater density than that of a 

 natural park. In the prairies of southern 

 Canada, and of the ^Mississippi basin it is com- 

 mon although outnumbered by some other kinds, 

 especially by the yellow or Richardson's Ground 

 Squirrel. The settlement of these regions seems 

 to be causing the decrease of the striped but not 

 of the yellow species. One authority states that 

 the very shallow burrows and chambers of the 

 former are destroyed by plowing, and that the 

 deeper ones of the latter are only temporarily 

 plugged up. Since the burrows of the Striped 

 Spermophile are only about six inches below the 

 surface, plowing would not only destroy them, 

 but the young as well. 



The nesting burrow is complicated by many 

 twistings, turnings and branchings. There are 

 also several openings, some of which are occa- 

 sionally stopped up. The real home room is 

 about nine inches in diameter by six inches in 

 height. In addition to this type of burrow, there 

 is a simpler one, which may be used for tempo- 

 rary retreat from danger. To render the tunnel 

 entrance inconspicuous, the excavated dirt is 

 often scattered, and the opening hidden by a 

 bunch of grass, weeds and other objects. 



The Thirteen-striped Spermophile is appar- 

 ently the most carnivorous of all this family. 

 .A.S much as 46 per cent, of its stomach contents 

 has been found to be insects, caterpillars, 

 grasshoppers, cocoons, insect eggs, birds, rep- 

 tiles and mice. Offal of any kind of flesh is 

 eagerly seized upon. Lacking other meat, it will 

 eat its own relatives. For vegetable food, it 

 uses the same materials as others, grain and 

 seeds being the favorites. Food which will 

 spoil is never stored. Extra food is laid by 

 in side chambers made for the purpose. Since 

 the animal is asleep all winter, this food 

 must be used in the early spring when other 

 food is scarce. This is just the time, too, 

 when much food is needed. Because of their 

 long fast the animals are thin, and the mating 

 activities begin at once when they awaken. 



In late May or early June, the young are born. 

 The number varies from seven to fourteen, with 

 nine the average. They are among the most 

 helpless of young Ground Squirrels. Their eyes 

 do not open at once, and twenty days are 

 required for hair to appear on their naked 

 bodies. By the end of stmnmer, however, they 

 are full grown. 



The enemies of this species are the same as 

 those of other Spermophiles. In many of the 

 western States the larger hawks are protected 

 by law, partly because of their fondness for 

 Spermophiles and Prairie Dogs. Three and 

 even five western red-tailed hawks may often be 

 seen circling over colonies of these animals wait- 

 ing for a favorable opporttmity to swoop down 

 upon one. 



It is true that most Ground Squirrels take con- 

 siderable grain, and may pull up newly planted 

 seeds, but in the case of this species, the number 

 of harmful insects and mice destroyed more 

 than compensates for the damage done to the 

 growing crops. 



ANTELOPE GROUND SQUIRREL 

 Ammospermophilus leucurus ( Mcrriam ) 



Other Name. — A\'hite-tailed Spermophile. 



General Description, — Size small : head blunt and 

 rounded ; cars rounded and low ; body moderately thick- 

 set ; tail short, fairly bushy and flat, about one-third 

 length of head and body, carried turned up over 

 animal's back when running; hair moderately short; 



color above, grizzly gray with white stripe on either 

 side of back: underparts glistening white. 



Dental Formula. — Same as foregoing. 



Pelage. — .Adults : Sexes identical, seasonal varia- 

 tion not conspicuous. General color above, grizzled 

 gray ; vinaceous on head and rump with broad white 



