Least Chipmunk (Tamias minimus)

County List:

Rule:

Forested or Mixed Forested/Nonforested Landscapes

1st alternative:
      (Spruce/Fir (Any Size Class))
      or (Jack Pine (Any Size Class))
      or (Mixed Upland Conifer (Any Size Class)) 
      or (Mixed Pine (Any Size Class))
      or (Northern White Cedar (Any Size Class))
      or (Mixed Lowland Conifer (Any Size Class))
   containing:
      (Dead Down Woody Debris and Mast)
   adjacent to:
      Edge

2nd alternative:
      (Spruce/Fir (Any Size Class))
      or (Jack Pine (Any Size Class))
      or (Mixed Upland Conifer (Any Size Class)) 
      or (Mixed Pine (Any Size Class))
      or (Northern White Cedar (Any Size Class))
      or (Mixed Lowland Conifer (Any Size Class))
   containing:
      (Dead Down Woody Debris and Mast and Stand/Gap Openings)

Habitat List:

view size class definitions

Literature:

The least chipmunk dwells in and about the boreal forests of central and western North American. It avoids the closed interior of mature climax stands of conifers, preferring the more open forest edge and internal forest clearings. Disturbed areas surrounded by open stands of aspen and pine often harbor large populations. The least and eastern chipmunks occasionally occur together in deciduous habitats, but the eastern chipmunk prefers areas with greater cover.

Although it commonly scurries along the ground this squirrel also forages in shrubs and trees, at heights up to 30 ft. This small squirrel is active only from April until October; with the onset of cold weather, it retires to an underground burrow, frequently enters torpor, and lives off stored food until spring.

It builds its winter nest on top of a food cache in a chamber up to 3 ft below the surface. The nest consists of dried grass or shredded bark lined with feathers, fur, or soft vegetable matter.

In summer, a least chipmunk often abandons its burrow and builds another leafy nest in a rotting log or tree cavity.

Nuts, fruits, and seeds are preferred foods. Although it relishes blueberries, raspberries, and the like, it does not eat the pulp of these fruits. Instead, the squirrel opens the berries, removes the seeds, and leaves behind a pile of soft tissue. This rodent obtains extra protein in the summer by preying on insects and consuming an occasional bird egg.

Habitat Preferences: The least chipmunk is remarkably adaptable to various environments in its vast range. In western areas the species thrives in eroded badlands, in sagebrush flats, and even in alpine tundra. In Michigan, however, the least chipmunk is most at home in the various coniferous habitats of the Canadian Biotic Province. Although similar habitat also occurs in the northern part of the Michigan's Lower Peninsula, the least chipmunk has become established only in the Upper Peninsula, perhaps being unable to cross the Straits of Mackinac water barrier.

The least chipmunk is rarely found in the deep dense boreal forest but prefers the edges, especially surrounding small openings. It also lives along streams and lakeshores; in jack pine, sandy ridges, swamp edges, cutover, burnouts, cleared land, other disturbed areas, lumber camps, and under cabins. Apparently, the ecological successional changes caused by lumbering is a stimulus to populations increase. Strip clear-cutting in conifer swamps in Alger County allowed for a higher number of least chipmunks. Like the eastern chipmunk, the least chipmunk will occupy log piles, rock walls, and brush piles. Stumps and felled logs are favored den sites. Reilly found that Upper Peninsula least chipmunks occurred in largest numbers in sylvan habitats with good horizontal visibility, medium to dense brush piles for cover and open canopies with correspondingly high light intensities. The amount of low, woody ground vegetation appeared insignificant, although dense stands of bracken fern seemed to be avoided. Reilly noted that horizontal visibility was important in behavioral interactions and spacing of the population. The animals also occupy deciduous hardwood forest habitat, where they occur most often in edge situations and disturbed areas. In hardwood habitats least chipmunks associate frequently with eastern chipmunks. Although there are some indications that the least chipmunk is retreating northward in central Wisconsin, there is no evidence of any such decline in Michigan. Instead, it is thought that land management programs often produce highly favorable habitats for least chipmunks.

Behavior: Most movement is terrestrial, but it also perches or scurries across piles of debris, rock fences, outcroppings or treefalls. Chipmunks travel expertly through bushy understory or climb to the tops of food trees; Manville observed these chipmunks at heights of 12 ft in tag alders and 30 ft in jack pine.

Associates: Least chipmunks in the Upper Great Lakes Region may actually prefer swamp habitat while eastern chipmunks seem more at home in upland forested situations, there is some ecological separation.

Food Habits: The least chipmunk is primarily a vegetarian (eating mostly seeds, nuts, acorns and other reproductive parts of plants), although it will ingest insects, birds' eggs, and other animal materials.