FIELD BOOK OF MAMMALS 



mid-dorsal region; gray appearing in small spots to produce 

 dappled effect; top of head light brownish; hands and feet 

 light buffy; tail above, mixed gray, yellowish white and dusky, 

 below like upperside but with more yellowish white; pelage 

 of upperparts blackish at base. 



Underparts. — Dirty grayish white with buffy suffusion. 



Immature much like adults. 



Measurements.- — Sexes of equal size. Total length, i8 

 inches; tail vertebr£e, 8 inches; hind foot, 2.4 inches. 



Geographical Distribution. — Rocky Mountain district and 

 western states from Colorado and the Columbia River south 

 into Mexico. 



Food. — Seeds, nuts, acorns, grains, fruits, green vegetation, 

 and some animal food. 



Enemies. — Hawks, Coyotes, Foxes, Bobcats, Weasels, 

 Badgers, and most of the small carnivores. 



Species and Subspecies of the Genus Otospermophilus 



Colorado Rock Squirrel. — Otospermophilus grammurus gram- 



murus (Say). 

 As described. Found from eastern Colorado south into 

 Arizona, New Mexico, and western Texas, west into south- 

 eastern California. 

 Utah Rock Squirrel.- — Otospermophilus grammurus utah 



(Merriam). 

 Very close to typical grammurus but smaller, ears larger, 

 and back much redder. Found from the Wasatch Moun- 

 tains of Utah eastward into Colorado. 

 Texas Rock Squirrel. — Otospermophilus grammurus buckleyi 



(Slack). 

 Resembling typical grammurus but with black on the an- 

 terior half of the dorsal surface and with much more black 

 elsewhere; tail more bushy. Upperparts glossy black from 

 nose to lower back and rump; some sprinkling of gray on 

 flanks and thighs; hands and feet dark brown grizzled with 

 gray; tail mixed gray and black; underparts light grizzled 

 gray and dusky. Total length, 20 inches; tail vertebrae, 

 8.5 inches; hind foot, 2.4 inches. Found in southern and 

 western Texas. 

 Couch Rock SquirreL — Otospermophilus grammurus couchii' 



(Baird). 

 Resembling buckleyi in having much black on upperparts; 

 color pattern variable; head black and usually back gray, 

 but sometimes entire animal is black, occasionally dark^ 

 gray. Found in northeastern Mexico and reaching only 

 the southern part of Texas, in the canyons of the Rio 



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