Tamias minimus
(Least Chipmunk)

Description:
As its name implies, this species is the smallest chipmunk and actually, the smallest member of the squirrel family. All chipmunks are striped on their backs; the least chipmunk has alternating light and dark stripes on its back and sides, and the outermost stripe on the side is dark. It is whitish to yellowish underneath and its tail has black-tipped hairs with a reddish undertone. The sides are often reddish brown. Total length is about 7 to 8.5 (187-212 mm) inches and an adult weighs about 1 to 1.9 (30-55 g) ounces. A behavioral trait that helps distinguish this species is that it tends to hold its tail in a vertical position when moving. It is very difficult to differentiate from the yellow-pine chipmunk.

Range:
From portions of western Canada, south through Rockies and northern Great Lakes region.

Habitat:
Found in various habitats. Common in coniferous forests, but may also be found in clearcuts, deciduous woods, sagebrush, jack pine stands, and riparian zones; in western regions may even occur in alpine tundra. In Idaho, found in sagebrush, juniper, and lower-elevation coniferous forests adjacent to sagebrush. It seems to favor sagebrush areas.

Diet:
Feeds mostly on seeds, nuts, fruits, and acorns. In Idaho, known to be omnivorous, feeding on plant seeds, foliage, and arthropods.

Ecology:
This species, as are all chipmunks, diurnal. They may be active throughout the day, but they prefer sunny midday hours. They hibernate and may aestivate. They begin semi-hibernation in late October, but may awaken on warm winter days, and are fully active by mid-March. In Idaho desert lowlands below 4000 feet (1200 m), there is some evidence that they aestivate in early July, and reappear in late August or early September (with autumn rains) before returning to winter hibernation. Build winter nests up to 1 m below ground surface. Highly favorable habitats may contain 30 or more per acre (0.4 ha), though average densities typically range from 5 to 15 per acre (0.4 ha). Home range varies from less than 1 acre (0.4 ha) to 4 acres (1.6 ha). They are preyed on by hawks, weasels, martens and red foxes.

Reproduction:
Breeds in early spring. Gestation lasts 31 days. litter size varies from 2-7 young (average 5-6). Female produces 1 litter; if that litter fails, she may produce another. Young become sexually mature in first spring.

Conservation:

Status:	Unprotected nongame species
Global Rank:	G5
State Rank:	S5

Important State References:
Laundré, J.W. 1989. Burrows of least chipmunks in southeastern Idaho. Northwest. Natur. 70:18-20.