610 THE MONTHLY BULLETIN. 



Squirrel, encountered under the same circumstances, soon became accus- 

 tomed to the camera so that the photographer, himself at some little 

 distance, was able to release the shutter when the lens of the camera 

 was less than thirty inches from the animal photographed. Compared 

 with this, the Digger Squirrels proved exceedingly wary, refusing to 

 show more than their heads even though the camera was disguised and 

 placed six feet distant. The confidence of the Digger Squirrel could no 

 doubt be gained, given sufficient time; but when an approach was 

 attempted by the methods that had proven successful with the other 

 squirrels the results were nil. It looks as though the reactions of the 

 Digger Squirrel had been adjusted to meet that category of enemies 

 which lie in wait at jumping distance. 



Fig. 5. TjTJcal "hog-wallow" land showing trail and burrows of the California 

 Ground Squirrel. Photographed ten miles north of Fresno, April 10, 1911. 



Ground squirrels traveling to and fro, between their holes and their 

 feeding grounds frequently traverse the same courses until regular 

 radiating trails 2^ or 3 inches wide are worn through the grass (see 

 fig. 5). This is particularly well seen on many hillsides, and on the 

 rolling '^ hog-wallow " lands along the eastern side of the San Joaquin 

 Valley, where, in the fall, when the grass and weeds are dry, the trails 

 show most 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. 



In foraging for seed-pods, grain, or fruits, the ground squirrel does 

 not usually eat the food on the spot where it is gathered, but he stuffs 

 it into his capacious cheek pouches (see fig. 13) or else, if it is too 

 large for this, carries it in his mouth nipped between the incisor teeth. 

 He then repairs to some point of vantage such as a rock pile or to the 

 mound at the entrance of the burrow. Here he proceeds to hull and 

 devour the food at leisure and at the same time is near enough to shelter 

 so that he can quickly duck in should an enemy suddenly appear at 



18 



