166 ANIMAL LIFE IN THE YOSEMITE 



Afield, the observer often comes upon ground squirrels which are some 

 distance from their holes. Such animals usually run to the near vicinity 

 of their burrows where they sit upright and can watch the intruder, yet 

 be in readiness to dart down into their holes at an instant's warning. 

 While thus on watch they utter, at short intervals, a rather musical whistled 

 note, clink. If the farther advance of the observer seems to portend danger 

 to them they utter a double note, clink, clink, sometimes with a sort of 

 chuckle added, and then drop down into the shelter of their subterranean 

 retreats. Ordinarily when thus frightened down, they do not reappear 

 at the surface of the ground for some time, as if to give the suspected 

 enemy plenty of chance to tire of his waiting and to depart. Occasionally, 

 however, a squirrel will crouch motionless almost at the feet of the observer, 

 as if to escape detection by remaining quiet. Extreme fear may be a part 

 of the basis for this manner of behavior. 



Ground squirrels, in traveling between their holes and their feeding 

 grounds, frequently traverse the same courses until regular trails are worn 

 through the grass. This is seen particularly well on the rolling lands 

 between Merced and Snelling, where, in the fall, when the grass and weeds 

 are dry, the trails show from a distance very distinctly. In the spring, 

 when the new growth is just appearing, the trails are still conspicuous, as 

 the vegetation is slower in starting there than in the adjacent unbeaten 

 tracts. Soon, however, the trails are entirely obliterated, save as the 

 animals renew them by further use. 



It seems likely that ground squirrels can, if necessity demands, go 

 without water for long periods of time, if not indefinitely. Many of the 

 plains-dwelling individuals of this species are so situated that it is im- 

 possible for them to get any water except such as may accumulate in small 

 surface depressions or in parts of their burrows for brief periods during 

 the rainy season. As a substitute for bathing in water these animals 

 take dust baths in the soft earth of fields and country roads. We have 

 frequently come upon places where tracks and marks in the dust showed 

 that squirrels had been 'dusting' themselves. This habit may afford partial 

 relief from the many fleas and mites with w^hich they are often afflicted. 



Ground squirrels, like chipmunks, are provided with inner cheek 

 pouches which are used while gathering and transporting food. Often 

 when the animals are scared out of bushes or trees, or away from some 

 supply of roots or bulbs which they have discovered, their cheeks are seen 

 to be bulging with the contents of these pouches. They are able to use 

 their teeth even when these pouches are widely distended. 



Ground squirrels are chiefly terrestrial in their forage habits, taking 

 whatever may offer in the way of seeds, grasses, fruits, low-growing annual 

 plants, roots, and especially bulbs like those of the common brodiaea. The 



