THE GROUND SQUIRRELS OP CALIFORNIA. 



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As far as is ta be observed, the male takes no active interest in the 

 welfare of the young. Indeed, he dwells altogether separately from the 

 family and does not see his offspring until they begin foraging out of 

 doors. His only function at all, as regards the upbringing of the 

 young, is that of sounding general alarm throughout the colony when 

 danger threatens. As for the mother, even she is notably indifferent 

 to her young after they appear above ground. When suddenly alarmed, 

 she flees to safety on her own account, leaving the youngsters to shift 

 each for himself as best he may. 



The rate of growth of the young is such that they reach mature size 

 by September, when they are from four to six months old (McCoy, 

 1912, p. 1069). But before this time, by the first of August, the young 

 of the year begin to emigrate locally, so as to establish each for himself 

 a new home. It is likely that this process of emigration is hastened by 

 the development on the part of the parents of an attitude of incom- 

 patibility. According to this idea the initial solicitude of the mother 

 for her young at the helpless age is later reversed, so that she becomes 

 antagonistic to them and finally speeds their departure. The young, 

 at the same time, begin to give evidence of an instinct to wander. At 

 any rate, the month of August sees the important phenomenon of emi- 

 gration or dispersion well under way. Young of the year then put in 

 their appearance in unexpected places ; new ground is invaded, and 

 the total territory occupied by the squirrels increased in extent insofar 

 as the increase in population makes necessary and the favorable nature 

 of the country permits. Undue congestion of population tends thereby 

 to be prevented. 



The natural enemies of the California Ground Squirrel are of many 

 kinds, and under original conditions so many as regards individuals 

 as to provide a regular automatic check to any abnormal increase of 

 the squirrel. The most important are golden eagles, red-tailed hawks, 

 coyotes, badgers, wildcats, weasels, rattlesnakes and gopher snakes. 

 Each of these various animals pursues the squirrels in its own particular 

 way. Hawks and eagles swoop down on them from their vantage points 

 in the air. Wildcats and coyotes lie in wait near the burrows until 

 the squirrels venture forth in search of food, when they pounce upon 

 them. Badgers, weasels and snakes capture the squirrels in their bur- 

 rows. Some specific cases will be cited here. It must be remembered 

 that, while casualties to squirrels may be inflicted by their customary 

 enemies almost hourly in any general neighborhood where man has not 

 exterminated these predators, the chances of a person's being in a 

 position at the critical moment to witness a tragedy of this sort are rare. 

 At the San Emigdio Ranch in Kern County on April 25, 1918, the 

 junior author watched a Golden Eagle (Aquila chrysaetos) capture and 

 devour an adult ground squirrel. The eagle was first observed flying 

 quietly down a canyon. By weaving in and out in its course the bird 

 was able to skirt the irregular hillside so as to keep within fifteen or 

 twenty feet of the ground. At length the eagle skimmed abruptly 

 around the shoulder of a hill, just clearing the tops of the wild oats, 

 and dropped quickly down upon a luckless ground squirrel. The latter 

 had evidently been on a foraging expedition and did not have time to 

 reach his burrow, so complete was the surprise. The eagle seized the 

 squirrel with both sets of talons, and the piercing grip by these effective 



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