304 The Rodentia. 



THE CHIPMUNKS. 



Chipmunks are often called Rock Squirrels because they 

 make their nests in crannies in the rocks or other places on 

 the surface, instead of living in underground burrows. 

 They are closely allied to the tree squirrels, but they 

 are given a separate genus because they have pouches 

 inside the cheeks, a slenderer and narrower skull, 

 shorter ears and tail, and the first premolar tooth in the 

 upper jaw is either absent or very minute; they are also 

 characterized by a peculiar coloration, that shows them to 

 be the connecting link between the arboreal tree squirrels, 

 and the ground squirrels like the susliks or spermophiles. 



The Common American Chipmunk (Tamias-striatus), 

 a small animal six inches long, with a four-inch tail, takes 

 its name from an American Indian word meaning the 

 hacking or chipping squirrel. Its range extends from 

 Canada and Manitoba through the eastern section of the 

 United States into Georgia and western Missouri ; the 

 long-eared Chipmunk of California (Tamias-macrotus), and 

 other western varieties, are distinguished from it by 

 the greater length of their ears and other characteristics. 

 The common Chipmunk is sometimes about the size of the 

 European squirrel, and in some localities has the same 

 ground color, but is always distinguished by the black 

 stripe running down the middle of the back and the white 

 stripe with black edges on each of its sides, as Vj^ell as the 

 two white stripes separated by a black one above and be- 

 low each eye. There is considerable local variation in the 

 ground color, that of the southern Chipmunks being 

 much lighter than that of those in the northern portions 

 of their habitat. They are the commonest of North Amer- 

 ican rodents, and are migratory in their habits, being 

 abundant in a certain district one year and entirely ab- 

 sent the next. They feed principally on beech mast, but 

 also consume corn and roots and the larvae of insects. 

 According to Dr. Merriam; when the beech nuts are 

 abundant in the Adirondack Mountains the Chipmunks 

 put in an appearance in September, and by October the 

 woods are alive with them. "They immediately estab- 

 lish themselves for the winter, and begin to hoard up 

 large stores of food. They are the least hardy of our 



