Some Sierran Chipmunks 



405 



their own existence. A Cooper Hawk gliding through the 

 trees along Bubbs Creek with a long tail dangling from his 

 claws, and a Western Red-tail Hawk, seen at Horse Corral 

 Meadow, making off with a satisfied air, a similar token of 

 success streaming below, bore convincing evidence of what 

 happens to the luckless chipmunk who relaxes his vigilance at 

 the wrong moment. 



At the time of our visit to Horse Corral Meadow, in late 

 September, the Douglas Squirrels were hard at work harvest- 

 ing nuts from the pine cones, being especially busy in the tam- 

 arack groves. Climbing to the upper branches, where the green 

 cones were numerous, the squirrel would cut them off as rap- 

 idly as possible, letting the cones drop to the ground. Twenty or 

 more might be severed in rapid succession (and far more quick- 

 ly than one would imagine possible) before the worker would 

 descend to carry them away, apparently to some secret cache. 

 On several such occasions an astute chipmunk was seen waiting 

 below the tree to reap a share of the harvest with the minimum 

 of effort. And the squirrel was never seen to take offense. 



It is difficult, perhaps impossible, to point out features 

 whereby the Tahoe Chipmunk may be unfailingly recognized, 

 and this, too, despite the fact that one familiar with the animal 

 can usually distinguish it at sight. In this, as with many other 

 species, it is probably a matter of learning to know them as one 

 knows one's friends. We may classify one species as having 

 a longer tail than another, but when we see one of the animals 

 at large we no more recognize it by its longer tail than we 

 recognize our friend on the street by his long nose ! Who can 

 say what it is about an intimate associate that causes recogni- 

 tion nearly as far as he can be seen? Surely no distinctive 

 "recognition marks." Similarly, when an animal species be- 

 comes familiar to a person it is frequently recognized through 

 an individuality that defies analysis. However, for a first ac- 

 quaintance some recognizable features are necessary, and the 

 following are suggested as of use in distinguishing this animal 

 in life. Compared with the Mariposa Chipmunk, the Tahoe 

 Chipmunk is of somewhat smaller size, with noticeably shorter 

 tail. Total length is about nine and a half inches, tail about 

 four and a half. The latter is jerked nervously about in a 



