CHIPMUXKS 187 



In places like this, on July 22, 1920, 5 chipmunks were checked in a 31/2 

 hours' census walk. A rattlesnake coiled under the lowest rail of a 

 fence was found to contain a partially digested chipmunk ; the snake had 

 evidently found the fence a favorable place for his own foraging. 



The actual floor of Yosemite Valley does not afford much appropriate 

 cover for the Mariposa Chipmunk. The animals live on the boulder talus 

 overgrown with brush and golden oaks along either wall ; they are most 

 numerously represented on the w^armer north side of the Valley. In 1915, 

 several chipmunks lived in woodpiles near certain of the buildings in the 

 Village, and they came regularly to take nuts and other food placed out 

 for them in front of the village barber shop. Once, on the north side of 

 the Valley, one of these chipmunks was seen to run across the road and 

 climb the slanting trunk of a willow which stood only about fifty feet from 

 the bank of the Merced River. 



The breeding season of the Mariposa Chipmunk begins very early in 

 the spring. A female captured at Blacks Creek, May 10 (1919), w^as 

 already suckling young; another individual taken that same day was a 

 young animal of the current season already over half -grown. On June 8, 

 1915, a half-grown young-of-the-year w^as collected on the ridge of hills 

 3 miles east of Coulterville, and another a little larger was taken on Smith 

 Creek July 16, 1920. All these young animals have the characteristic 

 pelage of young chipmunks, soft and rather scanty, with colors darker, 

 more blackish, than in adults. A female taken in Yosemite Valley July 29, 

 1915, was a young-of-the-year, of nearly adult size. It had assumed its 

 first summer coat. The Mariposa Chipmunk evidently breeds earlier than 

 does any of the other local species of chipmunk ; this fact is consistent with 

 the greater warmth of the animal's habitat. Its young are abroad in the 

 spring long before the young of high-mountain species have been born. 



Long-eared Chipmunk. Eutamias quadrimaculatus (Gray) 



Field characters. — A large chipnumk (head and body about 5i/^ inches, tail 3% 

 inches long); usual chipmunk pattern of markings; ears proportionately taller than in 

 any other species, and light spot behind base of each ear larger and more conspicuously 

 clear white. (See pis. 3d, 33a.) Distinguished from mariposae and senex by deep ruddy 

 brown rather than grayish tone of coloration, as well as by taller ears and conspicuous 

 white spot at base of same; may be separated from f rater by larger size, taller ears and 

 darker tone of coloration. (For comparative measurements see footnote 15, p. 177.) 

 Voice: A sharp ichsst or psst ; also a low-pitched hod: 



Occurrence. — Common resident in a narrow belt on west slope of Sierra Nevada 

 between altitudes of 5000 and 7300 feet (upper part of Transition Zone and lower part 

 of Canadian). Eecorded from Sequoia, Hazel Green, and Chinquapin eastward to Indian 

 Canon and to junction of Sunrise and Clouds Rest trails. Lives about brush patches and 

 logs, seldom going up in trees and then usually only a few feet above the ground. 



