Eastern chipmunk (Tamias striatus)

Synonyms: Sciurus striatus, Tamias americana
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderRodentia
FamilySciuridae
GenusTamias (1)
SizeHead-body length: 11.5 - 18.6 cm (2) (3)
Tail length: 7 - 11.5 cm (2)
Weight66 - 150 g (2) (4)
Top facts

The eastern chipmunk is classified as Least Concern (LC) on the IUCN Red List (1).

Named for its distribution in eastern parts of North America (5), the eastern chipmunk (Tamias striatus) is a small, predominantly ground-dwelling rodent with conspicuous stripes along its back (5) (6). These consist of five dark stripes separated by four light stripes, and extend from the eastern chipmunk’s shoulders to its rump (2) (3) (4) (5) (6) (7). The uppermost light stripes are generally greyish to brownish, while the lower ones are creamy white (2) (4) (6).

The rest of the eastern chipmunk’s upperparts are greyish to reddish-brown (3) (4) (5) (6), with a distinctive reddish patch on the rump (2) (4) (7). The underparts are white to buff (2) (3) (4) (5) (6). 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 (2) (5) (6), while its ears are short and rounded (5) (6).

The eastern chipmunk has moderately long, soft fur (3) (5), which may be paler in winter than in summer (5). It tail, while well furred, is not particularly bushy (3) (5) (6), and is blackish above and orange below, with a narrow whitish border (2) (5) (6). The male and female eastern chipmunk are similar in appearance (5).

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 (3) (6). 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 (4) (7). The intensity and shade of the eastern chipmunk’s colouration vary between different regions, and a number of subspecies have been described (6).

Like other chipmunks, the eastern chipmunk gives a variety of different calls, including low ‘chucks’, repeated high-pitched ‘chips’, and trills and chatters (2) (5) (6). These calls, often given from a raised vantage point (2), may be used in alarm or to defend territories (3) (6) (7). Several eastern chipmunks often call together in chorus (5) (7). Some studies have suggested that the eastern chipmunk may use different calls in the presence of different types of predators (8).

The eastern chipmunk is widespread across the eastern United States and south-eastern Canada (1) (2) (5) (7), occurring from Nova Scotia to south-eastern Saskatchewan in Canada, south through the eastern U.S. to Oklahoma in the west and Virginia in the east. Its range also extends south into the extreme northwest of Florida (1) (3) (6).

There is also an introduced population of eastern chipmunks on Newfoundland, off the coast of Canada (1) (7).

The eastern chipmunk generally inhabits deciduous forest and brushland with plenty of cover in the form of logs, tree stumps or rocky ground (1) (2) (3) (4) (6) (7). This species is relatively tolerant of humans, and can also be found in gardens and suburban areas, often around houses and outbuildings (2) (4) (5) (6) (7).

Although it sometimes climbs trees and shrubs to find food, the eastern chipmunk spends most of its time on the ground, where it excavates fairly extensive burrow systems (1) (2) (3) (4) (5). The burrow is usually built beneath a log or rock, at the base of a tree or under the edge of a building (1) (3), and generally consists of a series of interconnected tunnels with multiple entrances (2) (4). A nest of crushed or chewed leaves is built in an enlarged chamber, while other chambers are used to store food (4) (5) (6). On rare occasions, the eastern chipmunk has also been known to rear its young in a nest in a hollow tree (5) (6).

The eastern chipmunk is generally solitary and territorial, vigorously defending the area around its burrow against intruders (1) (3) (4) (5) (7). Active during the day, this small mammal feeds on a variety of seeds, fruits and nuts, as well as mushrooms, insects, earthworms, slugs, snails and birds’ eggs. It even sometimes takes small snakes, frogs, mammals and birds (2) (3) (4) (5) (6) (7).

Like other chipmunks, the eastern chipmunk has large internal cheek pouches which are used to carry food (3) (5) (6). Dry foods such as nuts and seeds are gathered in large quantities in late summer and autumn and transported back to the burrow to be stored for the winter (2) (4) (5) (7). This behaviour is aptly described by the eastern chipmunk’s scientific name, Tamias, which means ‘storer’ (5).

The eastern chipmunk hibernates in its underground burrow from around October to February or March, depending on the location (2) (3) (5) (7). Unlike many other hibernating mammals, the eastern chipmunk does not accumulate significant stores of body fat before winter, instead living off the food it has stored in its burrow. This means the chipmunk must wake frequently to feed, and it may even leave the burrow on warm days (2) (3) (4) (6) (7). The degree of torpor varies between individuals and between populations, with some remaining dormant throughout the winter, while others are more active (3) (5) (6).

Male eastern chipmunks typically emerge from hibernation earlier than females (5) (7), although severe weather may cause both to return to their burrows (3) (5). Uniquely among hibernating Sciuridae species, the eastern chipmunk can have two breeding periods a year (3) (5) (7), the first between February and April and the second between about June and August (1) (3) (6).

The female eastern chipmunk usually gives birth to a litter of around 3 to 5 young in an underground nest, after a gestation period of 31 days (1) (2) (4) (6). The young are born blind and hairless, weighing about three grams (3) (4), and emerge from the burrow five to six weeks later (3) (5). Some female eastern chipmunks may go on to have second litter later in the summer (2) (3) (5) (7).

Young eastern chipmunks reach adult size by about three months old (3) (6). A few females born in the spring may mate in the summer breeding season, but most individuals do not breed for the first time until the following year (3) (4) (5) (6). The eastern chipmunk usually lives for two to three years in the wild (1) (2) (3), although some have reached up to eight years in captivity (3) (5). This species is vulnerable to a range of predators, including snakes, weasels, foxes, bobcats, domestic cats and dogs, coyotes, hawks and owls (4) (5) (6).

The eastern chipmunk is a widespread and abundant species, and is not currently believed to be facing any major threats (1). However, there is evidence to suggest that it may be doing less well in fragmented forests and modified habitats (3) (5).

This species is often popular with humans (7) and can sometimes become quite tame, for example around campsites (3) (5). Despite its abundance, the eastern chipmunk only rarely becomes a serious pest on crops, stored food or in gardens (3) (5), and it may benefit humans by keeping harmful insects in check (7).

There are not known to be any specific conservation measures currently targeted at this common species. However, its range includes several protected areas (1).

If needed, potential conservation measures for the eastern chipmunk could include maintaining suitable refuge sites such as fallen logs and rock piles (5).

Find out more about the eastern chipmunk and its conservation:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (February, 2012)
    http://www.iucnredlist.org/
  2. Reid, F.A. (2006) A Field Guide to Mammals of North America. Houghton Mifflin Company, New York.
  3. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
  4. Kurta, A. (1995) Mammals of the Great Lakes Region. University of Michigan Press, Ann Arbor, Michigan.
  5. Schwartz, C.W. and Schwartz, E.R. (2001) The Wild Mammals of Missouri. Second Revised Edition. University of Missouri Press, Columbia, Missouri.
  6. Snyder, D.P. (1982) Tamias striatus. Mammalian Species, 168: 1-8. Available at:
    http://www.science.smith.edu/msi/pdf/i0076-3519-168-01-0001.pdf
  7. Hazard, E.B. (1982) The Mammals of Minnesota. University of Minnesota Press, Minneapolis.
  8. Burke da Silva, K. Kramer, D.L. and Weary, D.M. (1994) Context-specific alarm calls of the eastern chipmunk, Tamias striatus. Canadian Journal of Zoology, 72(6): 1087-1092.