Page:Natural History of the Ground Squirrels of California.djvu/106

686 been born generally during the early part of July, in a few eases 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.

Other names.—Antelope Chipmunk, part; Antelope Squirrel; Harris Chipmunk; White-tailed Spermophile; Charming Spermophile; Ammo; Tamias harrisi; Spermophilus 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 2½ 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