174 ANIMAL LIFE IN THE YOSEMITE 



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

 Sierra Nevada. Recorded from Aspen Valley, Merced Big Trees, and near Chinquapin, 

 eastward to Warren Fork of Leevining Creek and to Walker Lake. Lives on ground in 

 open forest and also in rocky situations. Diurnal. 



The Golden-mantled Ground Squirrel is one of the most conspicuous 

 members of the high mountain fauna, for it is the most brilliantly marked 

 of all the local squirrel tribe. People living in the mountains usually term 

 this species the "copperhead" or yellow-headed chipmunk, both of which 

 names are appropriate as applying to the coloring on the head and 

 shoulders (pi. 2). In general ecology this squirrel is the high-mountain 

 counterpart of the well-known California Ground Squirrel of the lowland 

 valleys and foothills. 



In size the copperhead is our smallest ground squirrel. It is about 

 three-fourths the size of the Belding Ground Squirrel and only one-third 

 or one-fourth the size of the California Ground Squirrel. It is larger, 

 however, than any of the chipmunks. Its general appearance, with stout 

 body and short tail, readily classifies it as a terrestrial squirrel rather than 

 as a climber. 



The range of the copperhead practically coincides with that of the 

 lodgepole pine; yet the squirrel is in no way dependent upon this tree 

 directly. The lowest station of record for the "callo," as members of our 

 party got in the habit of calling the animal for short, is at Merced Grove 

 Big Trees, altitude 5500 feet, a place which also marks the western limit 

 of its range. Across the Sierras the whole of the Canadian and Hudsonian 

 zones is inhabited, eastward to Walker Lake; sparingly to Mono Craters. 

 On the high peaks this species does not seem to go much above timber line. 

 Thus, on Mount Florence, the last individual was seen at 10,700 feet, which 

 was just above the highest stunted white-bark pines. On one occasion, 

 at Gaspipe Spring, east of Mono Mills, one of these squirrels was come upon 

 on the ground in the sagebrush, "miles from any timber." 



The main habitat or niche of this squirrel is the open rock-strewn floor 

 of the' sparse lodgepole pine forest. It keeps closely to this sort of environ- 

 ment, while the Belding Squirrel inhabits the open meadows. At the 

 margins of the meadows, however, the two are often seen in association. 

 The "callo" is strictly a ground dwelling animal. When it wants to look 

 about, it may go to the top of a low boulder or of a log. Only once did 

 we catch sight of one in a tree, and that individual when frightened ran 

 down to the ground and quickly sought its burrow. 



The "callo" when first met with is rather shy and usually scampers 

 to the vicinity of its burrow, where it sits hunched up, like a California 

 Ground Squirrel, ready to dart into its underground retreat at an instant's 

 further warning. But its confidence can be won; about camps it may be 



