CHIPMUNKS 



177 



size; coloration brighter than in any of the others, with light stripes on sides of head, 

 and back whiter. Voice : A moderately high-pitched whisic repeated at intervals ; also 

 a very shrill tsew, and, when frightened, a rapid series of notes, pst-pst-pst-a-hu. 



Occurrence. — Common resident in Canadian and Hudsonian zones on both slopes of 

 Sierra Nevada. Eecorded from Crane Flat and near Chinquapin eastward across moun- 

 tains to Walker Lake. Extreme altitudes, 6200 and 10,350 feet. Lives in forest, forag- 

 ing both in trees and on ground, rocks, and logs, but habitually takes refuge in trees, 

 going 40 feet or more above ground. 



The Tahoe Chipmunk is the most widely distributed and perhaps the 

 most abundant of the seven species of chipmunks inhabiting the Yosemite 

 section.^^ Its range embraces all of the forested portions of the "high 

 Sierras" between altitudes of 6200 and 10,350 feet. In the wooded terri- 

 tory immediately above Yosemite Valley, as at Glacier Point and back 

 of Yosemite Point, the species is abundant, while farther to the east, at 

 Merced Lake and Tuolumne Meadows, it is also well represented. 



The Tahoe Chipmunk is the only one of the local chipmunks which 

 habitually takes refuge well up in trees. This trait alone will, as a rule, 

 serve to distinguish the species from any of its relatives. In point of size 



15 Since relative sizes of the whole animals, and proportions of foot, ear, and tail, 

 constitute important characters of the seven species of chipmunks found in the Yosemite 

 section, we give here a table of their measurements and weights. These are based upon 

 ten adult individuals of each species, all of these having been captured within the section. 



Tn order of size, as based on average weights of 8 to 10 selected adult examples in 

 each case, the species align themselves from small to large as follows: (1) Eutamias 

 alpinus (34.5 g.); (2) Eutamias pictus (35.0 g.) ; (3) Eutamias a. monoensis (43.0 g.); 

 (4) Etitamias s. frater (59.2 g.) ; (5) Eutamias m. mariposae (63.5 g.) ; (6) Eutamias 

 quadrimaeidatus (87.6 g.) ; (7) Etitamias senex (88.1 g.). It will be seen that the 

 largest species is nearly 2^4 times as heavy as the smallest. 



