68 



NORTH AMERICANi FAUNA 66 



Distribution in Maryland. — ^Uncommon in the Eastern Shore and 

 Western Shore sections ; abundant locally in the Piedmont and Eidge 

 and Valley sections. In the Allegheny Mountain section it is replaced 

 by the subspecies T. s. lysteri. (see fig. 26.) 



Distinguishing characteristics. — Teeth 1/1, 0/0, 1/1, 3/3, = 20; a 

 small, heavyset ground squirrel with dense, moderately fine fur; 

 pelage marked by two pale and three dark stripes on sides of face 

 and five blackish and four pale stripes extending down the back; 

 rump rusty in coloration; top of head and dark facial stripes near 

 russet, light facial stripes pale buffy; dark stripes on back nearly 

 black in color, paler stripes near smoke-gray shading posteriorly into 

 russet; center or inner pale stripe is the broadest and always gray in 

 coloration; tail moderately long, grayish red and not bushy. This 

 species may be distinguished from any other in Maryland by the 

 striping pattern of the pelage. 



Measurements. — Four adults from the District of Columbia have 

 the following external measurements: Total length 243.2 (234-255) ; 

 tail 90.2 (83-99) ; hind foot 34.1 (33-35). Cranial measurements of 

 nine adults from the vicinity of Washington, D.C., are as follows: 

 Greatest length 39.5 (38.9-40.3) ; zygomatic breadth 22.0 (21.3-22.8) ; 

 postorbital breadth 11.2 (10.6-12.2) ; length of nasals 13.2 (12.5-14.0). 



Habitat and habits. — The chipmunk is largely a ground dweller, 

 only rarely climbing trees. It prefers to live on wooded hillsides or 

 mountain slopes, but is also fond of stone walls and rail fences. Though 

 usually favoring dry situations, it is occasionally found in moist bot- 

 tom land woods. It spends a good deal of time in burrows which it 

 digs beneath a rock, stone wall, tree roots, or a building. The burrow 

 is sometimes as much as 20 feet in length and 1 to 3 feet below the sur- 

 face of the ground. The chipmunk in Maryland remains more or less 

 active during the winter. All summer long, and especially in the 

 autumn, it is busily engaged in storing food, primarily seeds and nuts 

 for winter use. This food is kept in a "storeroom" adjoining the rooms 

 where the animal is spending the winter. The food of the chipmunk 

 consists of small seeds, berries, fruits, and nuts, and occasionally small 

 birds, mice, snakes, snails, slug, insects, and other small animal life. 

 Chipmunks are polyestrous and breed from March onward. The num- 

 ber of young is three to five, and the gestation period 31 days. Puberty 

 is reached at the age of 2i^ to 3 months. 



Specimens examined. — Anne Anmdel County: Epping Forest (near 

 Annapolis), 2. Frederick County: Catoctin State Park, 1. Harford 

 County: Fallston, 3. Howard County: Long Corner, 2. Montgomery 

 County: Bethesda, 1; Chevy Chase, 2; Dickerson, 1; Eockville, 3; 

 Takoma, 1 ; Washington Grove, 2; Linden, 1. Prince Georges Cownty : 

 Laurel, 5. District of Columbia: 42. 



