GROUND-SQUIRRELS 151 



western group includes the rock-squirrels, 

 which are never seen far from cliffs or broken 

 ledges. Bailey 'tells us that they climb the trees 

 for acorns and berries, but when surprised al- 

 ways rush to the ground and scamper away to 

 the nearest rock-pile. They are extremely 

 wary. "Like most of the smaller ground- 

 squirrels of the arid regions they usually bur- 

 row under a cactus or some low thorny bush, 

 where they obtain shade and the protection of 

 thorny cover. They apparently do not hiber- 

 nate, but during the cold weather have the un- 

 squirrel-like habit of closing their burrows and 

 remaining inside, as a protection against en- 

 emies, and especially snakes. . . . Like 

 other members of the genus, these ground- 

 squirrels feed on seeds, grain, fruit, green 

 foliage, lizards, and numerous insects, and 

 often gather around gardens and green fields, 

 where they do considerable damage in spring 

 by digging up corn, melons, beans and various 

 sprouting seeds, and, in summer and fall, by 

 feeding on the ripening grain." 



Squirrels and bubonic plague. One of these 

 ground-squirrels, that most common in central 



