The least chipmunk (Neotamias minimus) is the smallest species of chipmunk and the most widespread in North America.

Description

It is the smallest species of chipmunk, measuring about in total length with a weight of . The body is gray to reddish-brown on the sides, and grayish white on the underparts. The back is marked with five dark brown to black stripes separated by four white or cream-colored stripes, all of which run from the nape of the neck to the base of the tail. Two light and two dark stripes mark the face, running from the tip of the nose to the ears. The bushy tail is orange-brown in color, and measures long. In some areas, where range overlap with the yellow-pine chipmunk occurs, it may be difficult or impossible to distinguish the two species in the field; laboratory examination of skeletal structures may be required.

As in other chipmunks, there are four toes on each of the forefeet and five on the hindfeet. Females have eight teats. The brain to body mass ratio for least chipmunks is lower than that for other species of chipmunk living in the same area, suggesting that they prefer less complex environments.

Distribution and habitat

Least chipmunks are found through most of the western United States from northern New Mexico and western North and South Dakota to eastern California, Oregon and Washington, and throughout much of southern and western Canada from Yukon and southeastern British Columbia to central Ontario, and into the Upper Peninsula of Michigan and neighboring parts of Wisconsin and Minnesota. Less arboreal than other chipmunks, Home ranges vary widely, and have been reported to vary from in northern Michigan Because of their small size, least chipmunks are generally subordinate to yellow-pine chipmunks, which are able to drive them away from food resources where food is plentiful. However, because they need to eat less food in order to survive, least chipmunks are more numerous where resources are scarce. They are agile animals, and have been recorded running at speeds of up to in natural conditions.

Predators include hawks, owls, and mustelids.

Least chipmunks spend the winter in burrows and also scatter-hoard food in numerous concealed pits beneath logs and similar cover. Burrows consist of a single chamber about across and tunnels in diameter, averaging in length. They have two to four entrances, often concealed by nearby rocks, and are typically about below the surface. or appropriate hollows made by woodpeckers.

  • N. m. chuskaensis <small>Sullivan and Petersen, 1988</small>. Chuska mountains, Arizona.
  • N. m. confinis <small>Howell, 1925</small>. Bighorn Mountains, Wyoming and Montana.
  • N. m. consobrinus <small>Allen, 1890</small>. As far south as the Kaibab Plateau and as far north as southeastern Montana. It occurs throughout the Wasatch range in Utah as well as western Wyoming and northwestern Colorado.
  • N. m. hudsonius <small>Anderson and Rand, 1944</small>. North of N. m. borealis from northeastern Saskatchewan to northern Ontario.
  • N. m. jacksoni <small>Howell, 1925</small>. Southeastern Manitoba to northern Minnesota, Wisconsin and northeastern Michigan.
  • N. m. minimus <small>Bachman, 1839</small>. Southwestern Wyoming to northwestern Colorado.
  • N. m. neglectus <small>Allen, 1890</small>. Southeastern Quebec, southwestern Ontario, and the eastern upper peninsula, Michigan.
  • N. m. operarius <small>Merriam, 1905</small>. The southern Rocky Mountains from southern Wyoming to northern New Mexico, as far west as eastern Utah.
  • N. m. oreocetus <small>Merriam, 1897</small>. Northern Montana to central Alberta.
  • N. m. pallidus <small>Allen, 1874</small>. Eastern Montana and northeastern Wyoming. Occurs as far east as central North Dakota and extreme western Nebraska.
  • N. m. pictus <small>Allen, 1890</small>. South-central Idaho to east-central Utah.
  • N. m. scrutator <small>Hall and Hatfield, 1934</small>. The great basin from eastern Utah across Nevada to central Oregon. Reaches as far north as southern Washington. Also occurs in the Sierra Nevada of California.
  • N. m. selkirki <small>Cowan, 1946</small>. Central Purcell Mountains, British Columbia.
  • N. m. silvaticus <small>White, 1952</small>. The Black Hills of western South Dakota and northeastern Wyoming.

The Peñasco least chipmunk (N. m. atristriatus) occurs only in the Sacramento mountains of New Mexico where it is threatened by habitat loss. It has been proposed for listing under the endangered species act.

The Coulee chipmunk was considered a subspecies of the least chipmunk until it was recognized as a distinct species in 2022.

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Neotamias minimus on the first peak of Stawamus Chief (DSCF7696).jpg|Neotamias minimus (side)

Neotamias minimus on Stawamus Chief (DSCF7729).jpg|Neotamias minimus (front)

Chipmunk 2006.jpg|Least chipmunk

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References