182 CALIFORNIA MAMMALS. 



I have taken Pikas in six localities in the Sierra Nevada and 

 in the Warner Mountains. All these localities were similar and 

 are typical of those the Sierra Nevada Pikas prefer. These are 

 what are sometimes called ''rock slides."" On a steep slope where 

 favorable rock occurs the frost and weather loosens blocks of 

 rock, which roll down the mountain side, and the supply being- 

 continued the slope becomes covered many feet deep with blocks 

 of rock from a few inches to several feet in diameter, generally as- 

 sorted to size in certain parts of the slope. The angle of the slope 

 is as steep as the blocks will lie. These slides often cover many 

 acres. Among the interestices of these slides the Pikas make 

 their homes, foraging on the herbage growing around the slides. 

 They live in small communities, but m}' impression is that none 

 of the localities that I have seen were inhabited by more than two 

 or three dozen individuals, and in some probably but two or three 

 families lived. 



The food of Pikas is said to be "grass," but there is very 

 little grass to be found in the neighborhood of any of the colonies 

 that I have seen. Probably most of the plants growing within 

 their reach are eaten. They are said to cut and cure grass for 

 winter food ; this "hay" being stored among the rocks after dry- 

 ing in the sunshine. The only instances of this kind that I have 

 seen were on the Warner Mountains in July, when I found several 

 piles of twigs, mostly of "Choke cherry" twigs. Some of these 

 piles were of scarcely wilted twigs, while others were old, apparen- 

 ly cut the previous season. These twig piles appeared so much 

 like the nests of wood rats {Ncotoma) that I got the impression 

 that they were really used for shelter and secondarily for food 

 when other food ran short. I have not had the opportunity of 

 observing the Pikas late in the season when they would naturally 

 be curing "hay." 



The lowest altitude in which I have found Pikas is 6,700 feet 

 and the highest about 10,000 feet. The Pikas run about on the 

 rocks much as a rat would. I happened to see one on a bit of level 

 ground at the foot of a slide; it hopped along much as a young 



