THE GROUND SQUIRRELS OF CALIFORNIA. 



659 



beginning hibernation at the same points was one and one-half to two 

 weeks later. Individuals have been reported to us as seen aboveground 

 as late as the first week of September, but all reports agree that the 

 majority are ' ' holed up" before the first week in August. 



In the spring the animals reappear often when there is yet much 

 snow on the ground. In 1916 they were out in force on March 16, when 

 they had burrowed up in places through two feet of snow and were 

 nibbling the sagebrush tips (W. C. Jacobsen, MS). 



Enemies of the Oregon Ground Squirrel were, under original condi- 

 tions, doubtless numerous and effective in keeping down its numbers. 

 Gopher snakes, rattlesnakes, badgers, coyotes and Swainson Hawks are 

 known to feed regularly on it. Mr. J. O. Miller, a professional trapper 

 living at Yreka, inf orms us that nine out of ten coyotes trapped by him 

 during the summer months have remains of ground squirrels in their 

 stomachs. One coyote taken in Butte Valley had parts of seven Oregon 

 Ground Squirrels in its stomach. An old-time resident near Alturas 

 told the senior author that the killing off of the "varmints" (predaceous 

 animals) in recent years seemed to him to have had something to do 

 with the increase and spread of ground squirrels. We are strongly 

 inclined to his belief. Encouragement of those natural enemies which 

 are not in themselves seriously detrimental to man's interests would go 

 far to check the undue increase of the ground squirrels. 



BELDING GROUND SQUIRREL. 

 Citellus beldingi (Merriam). 



PLATE III. 



Other names. — Belding Spermophile; Bob-tailed Spermophile; Prairie Dog, part; 

 Picket-pin, part ; Spermophilus elegans ; Spermophilus beldingi ; Colobotis beldingi. 



Field characters. — A medium-sized, short-tailed, "picket-pin" type of ground 

 squirrel, without side-stripes or other conspicuous markings, but with bright reddish 

 brown back. Length of body alone about 7f inches, with tail 2f inches more. 

 (Closely similar to Oregon Ground Squirrel, but smaller and with back reddish 

 brown instead of brownish gray; compare figs. 20a and 20b.) 



Description. — Adult in full fall pelage : Sides of head, hind neck, shoulders, sides 

 of body and flanks continuously yellowish brown (numerous fine hairs which are 

 chiefly black, though light- tipped, lend a dusky tone to these areas) ; a tinge of olive- 

 ochre pervades the lower margins of those areas adjoining the light underparts ; eyelids 

 white ; whiskers black ; ears dusky, finely haired, not tufted ; crown of head to nose, 

 tawny-olive; a broad sharply outlined band of bright hazel brown running down 

 middle of back from between shoulders, narrowing to base of tail. Tail short, full- 

 haired, flattish ; above mixed hazel and black, black predominating toward end, where 

 also a well-defined buffy white fringe ; under surface of tail conspicuously deep 

 cinnamon-rufous, with subterminal black interval, and buffy white fringe all around. 

 Upper sides of feet buffy white ; claws chiefly black, with horn-colored tips ; palms 

 naked ; soles naked save for sparse hairing from heel halfway to tubercles. Under 

 side of head and neck, and inner sides of fore and hind legs, buffy white ; belly 

 cream-color, with lead-color of bases of hairs showing through. 



Color variations. — As far as we can see from the series of specimens studied, 

 adults molt but once a year, during July. May and June specimens show clearly 

 the effects of wear and fading, and are grayer, with the mid-dorsal brown area much 

 duller than in the fresh pelage described above. Young not one-fourth grown are like 

 adults in color, but with mid-dorsal area paler, snuff brown, and under side of tail clay 

 eolor. 



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