CHIPMUNKS 191 



distinguish between the two. However, alpinus has not been found east 

 of Warren Fork of Leevining Creek and Mono Pass and monoensis is not 

 known to occur west of those stations. At Glen Aulin the range of the 

 Allen Chipmunk meets that of the Alpine. But the latter is only about 

 half the bulk of the former and its coloration is obviously lighter, so that 

 no difficulty will be experienced in distinguishing these two species. 



The range of the Alpine Chipmunk comprises chiefly the Hudsonian 

 Zone, including the 'tongues' of that zone which extend westward from 

 the main Sierran crest to such outstanding peaks as Mount Hoffmann and 

 Mount Clark. The species ranges upward beyond the limits of the main 

 forest, and in a few instances was noted above the highest indication of 

 timber line and hence within the Arctic-Alpine Zone. For example, one 

 was seen at 11,500 feet altitude on Parsons Peak. 



This species inhabits for the most part rocky situations, either the large 

 masses of slide rock on the canon sides or the scattered boulders within the 

 rather open stands of lodgepole pine. Not infrequently it is seen scamper- 

 ing over and about logs lying on the ground, and in a few instances indi- 

 viduals were seen in trees. On Mount Hoffmann an Alpine Chipmunk was 

 seen 3 feet above the ground in a white-bark pine, and another at Ellery 

 Lake was 6 feet up in a lodgepole pine ; at Young Lake one of the animals 

 was seen -to climb several feet up into a lodgepole pine on the lake shore. 

 But the rock piles constitute the accustomed habitat ; individuals traverse 

 these with great facility, and venture much farther into such places than 

 do the Tahoe Chipmunks. Although we found no nests, we believe that the 

 Alpine Chipmunk finds its shelter and suitable breeding dens either amid 

 the rocks or in the ground beneath them. 



Bearing in mind the liveliness of chipmunks in general, the Alpine 

 Chipmunk must be put down as exhibiting the extreme of agility, so nimbly 

 and lightly does it skip about from place to place in carrying on its daily 

 activities. A^p^en running on the ground it usually holds the tail up 

 vertically and so gives the impression that this member is larger and longer 

 than actual measurements show it to be. When a chipmunk is perched on 

 some rock, and calling, its tail is usually jerked upward at the instant each 

 note is given. 



This chipmunk does not seem to be so talkative as some of its relatives. 

 Certainly upon many occasions when the presence of an observer would 

 provoke other species to loud and persistent chipping, alpinus gave few or 

 no notes. Its calls as compared with those of the Tahoe Chipmunk are 

 fainter and higher pitched. Once learned by an observer they can be 

 used with considerable certainty in identifying the species. A common 

 call is a repeated sweet, sweet, sweet, etc., with rather short intervals 

 between the notes and continued for varying lengths of time. If badly 



