Named for its distribution in eastern parts of North America, the eastern chipmunk (Tamias striatus) is a small, predominantly ground-dwelling rodent with conspicuous stripes along its back. These consist of five dark stripes separated by four light stripes, and extend from the eastern chipmunk’s shoulders to its rump. The uppermost light stripes are generally greyish to brownish, while the lower ones are creamy white. The rest of the eastern chipmunk’s upperparts are greyish to reddish-brown, with a distinctive reddish patch on the rump. The underparts are white to buff. The eastern chipmunk’s face is marked with a whitish stripe above and below the eye, a dark stripe across the eye, and orange-brown cheeks, while its ears are short and rounded. The eastern chipmunk has moderately long, soft fur, which may be paler in winter than in summer. It tail, while well furred, is not particularly bushy, and is blackish above and orange below, with a narrow whitish border. The male and female eastern chipmunk are similar in appearance. As well as being larger than other chipmunks, the eastern chipmunk can also be distinguished from related species by its reddish rump and relatively shorter tail. Where it overlaps with the least chipmunk, Tamias minimus, the eastern chipmunk can be distinguished by its less extensive stripes, which extend only to the rump rather than to the base of the tail. The intensity and shade of the eastern chipmunk’s colouration vary between different regions, and a number of subspecies have been described. Like other chipmunks, the eastern chipmunk gives a variety of different calls, including low ‘chucks’, repeated high-pitched ‘chips’, and trills and chatters. These calls, often given from a raised vantage point, may be used in alarm or to defend territories. Several eastern chipmunks often call together in chorus. Some studies have suggested that the eastern chipmunk may use different calls in the presence of different types of predators. The eastern chipmunk has large cheek pouches, which it uses to carry food. Although it can climb trees, the eastern chipmunk spends most of its time on the ground and excavates quite extensive tunnel systems.
