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THE MONTHLY BULLETIN. 



been born generally during the early part of July, in a few cases as 

 late as early August, to judge from the relative sizes of the young seen 

 abroad. The first to appear aboveground were noted on July 17 at 

 Bluff Lake. These were about one-third grown and seemed quite able 

 to forage independently of their parent. The latter paid no attention 

 whatever to them, only giving the sharp alarm note if an intruder was 

 sighted. 



Two young ones trapped alive were taken home to Pasadena and kept 

 in a cage. Early in the autumn one killed the other. The remaining 

 individual survived for three years, latterly inhabiting a rock-pile in 

 the yard and ranging freely where he would. Each winter he spent 

 about seven months, October to April, inclusive, in hibernation (see 

 fig. 25), with only occasional periods of activity for a day or two during 

 spells of warm weather. It is interesting to note that this inclination 

 to lie dormant was thus shown strongly at the low altitude of Pasadena, 

 where the winter temperature scarcely ever reached the freezing point. 

 There could have been no practical reason for it as regards failure of 

 food, for a supply was always provided the animal in abundance. The 

 annual program seems to require the dormant period, and this comes 

 on at a regular time, and lasts the usual period, whether or not it 

 happens to be essential to the survival of the individual. It is an 

 inherited trait of the race. 



DESERT ANTELOPE GROUND SQUIRREL. 



Ammospermophilus leucurus leucurus (Merriam). 

 plate v. 



Other names. — Antelope Chipmunk, part ; Antelope Squirrel ; Harris Chipmunk ; 

 White-tailed Spermophile ; Charming Spermophile ; Ammo ; Tamias harrisi; Spermo- 

 philus harrisii; Tamias leucurus; Citellus leucurus; Spermophilus leucurus; Citellus 

 leucurus vinnulus ; Citellus vinnulus; Ammospermophilus leucurus vinnulus. 



Field characters. — A small grayish brown ground squirrel with one white stripe on 

 each side of body and with a short flat tail nearly always held cocked up over its 

 rump so as to show the white under side conspicuously. Length* of body alone about 

 6 inches, tail about 2\ inches more. 



Description. — Adult in winter pelage : General color effect on upper surface from 

 nose to base of tail light brownish drab, changing on shoulders, flanks and outer 

 sides of fore and hind legs to light pinkish cinnamon. Close inspection shows a 

 grizzling, due to variegation of colors on the individual hairs, these being, on middle 

 of back for example, plumbeous at extreme base, then pale gray, then black, then 

 brown, and finally white-tipped ; some of the hairs on sides and rump are longer than 

 the average and black to ends. A sharply-defined narrow white stripe on each side 

 of body from shoulder to side of rump. Eyelids white ; ears and sides of head buffy 

 white ; whiskers black. Whole lower surface of body, from chin to root of tail, silvery 

 white, the bases of the hairs lead-color. Soles of hind feet densely white haired 

 forward to tubercles (see fig. 26a), thence to balls of toes naked, and plumbeous in 

 color in dried specimens; outer sides of hind feet and tops of fore feet tinged with 

 pinkish cinnamon ; feet otherwise dull white ; claws blackish brown with pale horn- 

 colored tips. Tail broadly haired and blunt-ended, narrowed at base; above mixed 

 black and white, giving an iron-gray effect, but, analyzed in its terminal half, an 

 outermost white border is seen to be preceded inwardly by a black band, then by a 

 white band, then centrally by black ; toward the root of the tail, above, there is a 

 tinge of pinkish cinnamon, this overlaid with a grizzling as on the back. Under 



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