Description.—The Townsend chipmunk is the largest of the chipmunks that occur in Washington. Head and body measure about 5-1/2 inches; the tail about 4-1/2 inches. The fur of the Townsend chipmunk is more lax and less sleek than that of other species. The upper parts are duller and darker ochraceous. Stripes are wide and not sharply delineated. The dark stripes are deep chestnut or blackish. The upper pale stripe is pale buffy gray; the lower is whitish. The tail is blackish frosted with white above and rich ochraceous below. Underparts are dull white.
The Townsend chipmunk ranges from the Fraser River in southern British Columbia through western Washington and Oregon, to central California. Like other members of the Pacific Coastal Fauna which extend southward to California, its geographic range extends farther inland to the south and geographic variation is greater; 3 races are listed by [Johnson] (1943: 114) in California.
The Townsend chipmunk is the largest and darkest chipmunk in Washington. Over much of its range it is the only chipmunk found although in some mountainous areas both townsendii and amoenus occur together. The larger size and richer coloration, especially the rich tawny color of the underside of the tail, separate Townsend chipmunks from amoenus.
Fig. 82. Townsend chipmunk (Tamias townsendii cooperi), captured on Goat Creek, 3,000 feet, western Cascade Mountains near Chinook Pass, Washington, September 16, 1940, by Earl J. [Larrison]; photographed February 1, 1941. (Fish and Wildlife Service photo by Victor B. [Scheffer], No. 1139.)
Townsend chipmunks are closely associated with the coniferous forest where they live in clearings and tangles of underbrush such as on steep hillsides, fire slashings, snowslide areas or mountain glades. Though capable of swift movement, they are less nervous and active than other chipmunks. Rarely are they as abundant, even locally, as other species, and the home range of an individual seems to be larger than that of an amoenus or a minimus. Rarely are more than two seen in a locality. Their more sedentary habits make them less conspicuous than other species. In the fall, when berries are dried out and seeds are ripe, they are most often seen. The Townsend chipmunk seems to be the most arboreal species found in Washington and individuals are not uncommonly seen in trees.
The brushy cover inhabited by Townsend chipmunks protects them from most hawks while their diurnal habits prevent owls from feeding on them. Predatory mammals probably constitute their greatest menace. A weasel (Mustela frenata) was seen to follow a Townsend chipmunk into a pile of timbers near Cottage Lake, King County, and another was seen carrying a dead Townsend chipmunk at Stevens Pass, King County. Tracks around an area of blood and fur showed where a mink (Mustela vison) had killed a Townsend chipmunk near Cottage Lake, King County.
