Tamias minimus
least chipmunk

Least chipmunks, Tamias minimus, are found throughout North America, occupying much of the Rocky Mountain region and the western Great Plains of the United States. In addition, they are found throughout central and western Canada and in parts of Wisconsin, Minnesota and Michigan. (Bergstom, 1999; Kurta, 1995)

Least chipmunks are found throughout the boreal and temperate forests of North America. However, least chipmunks prefer more open areas such as forest edges and openings. They are also commonly found near rock cliffs, river bluffs, and open jack pine stands. (Hamilton and Whitaker, 1979)

Least chipmunks are the smallest of all chipmunks. Body length ranges from 185 to 222 mm (Burt, 1946). Individuals weigh between 42 and 53 g. Females are larger than males in some populations (Berstrom, 1999) There are three dark and two light stripes on the face and five dark and four light stripes along their sides. The middle stripe runs to the end of the tail (Burt, 1946). Dorsal background fur is orangish-brown, and ventral coloration is grayish-white (Kurta, 1995). The tail is bushy and long, ranging from 81 to 95 mm, and is pale brown in color (Hamilton and Whitaker, 1979). (Bergstom, 1999; Burt, 1946; Hamilton and Whitaker, 1979; Kurta, 1995)

Because they hibernate, these chipmunks are heterothermic. However, their body temperature remains relatively constant over short spans of time. There is a lower body temperature when the animal is torpid than when it is active. (Bergstom, 1999)

The lifespan of these animals has not been reported. They are reported to have shorter lives than Eastern chipmunks, which can live as long as 11 years. (Baker, 1983)

Least chipmunks are adept climbers. Some individuals construct nests high above the ground. Chipmunks climb trees in order to warm themselves in the sun during periods of cool weather (Hamilton and Whitaker, 1979).

Least chipmunks are most active between April and October. Nests are built seasonally, with summer homes being constructed from leaves and bark in rotting logs and tree cavities. Winter nests are located in underground burrows that consist of dried grass, bark, fur, feathers and soft vegetation (Kurta, 1995). With the onset of cold weather, chipmunks retire to these burrows, where they enter torpor and live off stored food until spring (Kurta, 1995). Hibernation in these animals is not as deep as it is in ground squirrels, and they awake frequently to snack on stored food during the winter months (Bergstom, 1999). Least chipmunks are territorial and will defend their nests from invaders.

Least chipmunks are diurnal. In general, they are not social, except for mating and rearing young. However, when provisioned by humans, they are remarkably tollerant of conspecifics (Bergstrom, 1999). (Baker, 1983; Bergstom, 1999; Hamilton and Whitaker, 1979; Kurta, 1995)

Home Range

Home ranges have been estimated at 1/4 of an acre. Some areas have up to 6 individuals per acre. (Banfield, 1974)

Like other diurnal sciurids, vision is an important part of commmunication. Visual signals, such as body posture, convey important information to conspecifics.

In addition to visual communication, these animals use a variety of auditory signals to communicate. They use calls to advertize their ownership of a territory, to find mates, and when they feel threatened.

Tactile communication is important between mothers and their offspring, as well as between mates and rivals.

The role of olfactory cues in this species have not been described, but scents are often important in individual recognition. It is likley that there are some chemical cues used by these chipmunks in communication. (Baker, 1983; Bergstom, 1999)

Least chipmunks eat a wide variety of foods. Their diet including nuts, berries, fruits, grasses, fungi, snails, insects, and possibly some small birds and mammals. From April through October, much of a chipmunk's time is spent foraging. Least chipmunks forage both on the ground and in trees at heights up to 9 m (Kurta, 1995). Cheek pouches allow individuals to carry multiple food items back to their burrows, where they are either eaten or stored for future use. (Baker, 1983; Bergstom, 1999; Kurta, 1995)

Major threats to these animals include weasels, goshawks, Cooper's hawks, snakes, mink, red fox, bobcats, and martens, as well as domestic dogs and cats. (Baker, 1983; Bergstom, 1999)

As animals that carry nuts and seeds from one place to another, least chipmunks are probably very important in seed dispersal. They also play and important role as a food source to their predators. They also provide habitat for a number of parasites. (Baker, 1983)

Least chipmunks have no significant negative impacts on humans, though they may occasionally be a nuisance to campers (Hamilton and Whitaker, 1979). (Hamilton and Whitaker, 1979)

Least chipmunks are predators of pest insects and may play a role in seed or pollen dispersal.

The primary threat to least chipmunks is habitat loss caused by the encroachment of humans. Hunting or trapping may also pose a small threat. Currently least chipmunk populations are steady.