Unlike Norwegian Lemmings, Brown Lemmings do not migrate en masse when they overpopulate their homes in the treeless regions of the north, but they do tend to wander. These are stout-bodied, herbivorous rodents with extremely short tails. Their fur is tawny brown to cinnamon, and a rusty-colored patch can be seen on older adults. Brown Lemmings are most abundant in low-lying, wet habitats with sedges, grasses, and mosses. They cannot eat dried, dead plants; they must have living ones, so what they eat changes with the seasons. During winter months, they feed heavily on mosses, which are not very digestible. Brown Lemmings have to spend many hours in a 24-hour winter day feeding to get enough nourishment. Arctic predators, including snowy owls, least weasels, and Arctic Foxes rely on Brown Lemmings, and when Brown Lemmings are in short supply, these predators usually do not breed successfully.

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Mammal Species of the World

Widely distributed in northern North America from Alaska east to Baffin Island and south (in the west) to central British Columbia and (further east) to northern Manitoba. In Old World distributed in tundra to Kolyma in the west (Russian Federation). Several specimens found outside tundra, in middle Anadyr and Paren' Rivers, and lower Penzhina and Gizhiga Rivers.

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Alaska and the arctic tundra of Yukon, Northwest Territories, Nunavut, and Manitoba (east to Baffin Island and Hudson Bay), extending south down the western mountains into central British Columbia and western Alberta (Wilson and Ruff 1999). Also ranges across eastern Siberia, west to the Kolyma River (Jarrell et al. 1998).

Length: 17 cm

Weight: 113 grams

Sexual Dimorphism: Males are larger than females.

Length:
Average: 150 mm
Range: 130-180 mm

Weight:
Average: 80 g
Range: 45-130 g

Habitat and Ecology

Systems

• Terrestrial

Comments: Wet tundra and alpine meadows. Uses runways and tunnels. Nests above ground in winter, underground in summer.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Comments: Eats mainly grasses, sedges, and mosses; monocots always most important, mosses increase in importance in winter and in drier habitats (Batzli and Pitelka 1983). Also may eat bark and twigs of willow and birch in winter (Burt and Grossenheider 1976).

Populations may flutuate widely, peaking every 3-4 years. Frenzied dispersal occurs as populations peak and food supply dwindles; incurs high mortality during dispersal (Whitaker 1980). Home range reportedly is 3.5-6 sq yards (Whitaker 1980).

Comments: Active day and night.

Breeds mainly June-August. Probably 2 or more litters per year, usually 2-6 young per litter (Burt and Grossenheider 1976).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 109
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Population

Population Trend

Major Threats

Conservation Actions

Comments: The brown lemming was formerly referred to as Lemmus sibiricus, but the correct name for the North American population is Lemmus trimucronatus (Jarrell and Fredga 1993, Jones et al. 1997; also see following information). Batzli (in Wilson and Ruff 1999) used the name Lemmus sibiricus but acknowledged that Lemmus trimucronatus may be the correct name. The North American mammal checklist by Baker et al. (2003) listed this species as Lemmus trimucronatus, following Jarrel and Fedga (1993). Musser and Carleton (in Wilson and Reeder 2005) also recognized L. trimucronatus and L. sibiricus as distinct species, with only the former occurring in North America.

Pokrcvski et al. (1984) concluded that the brown lemmings in Siberia comprise two species, Lemmus sibiricus in the west and L. chrysogaster in the east. If the eastern Siberian form is conspecific with the North American form (see Rausch and Rausch 1975), then the correct name for the North American-eastern Siberian brown lemming is Lemmus trimucronatus (due to priority). If the North American form is not conspecific with L. chrysogaster, the correct name for the North American form is still Lemmus trimucronatus. North American brown lemmings can be called Lemmus sibiricus only if they are regarded as conspecific with the western Siberian population. See Musser and Carleton (in Wilson and Reeder 1993, 2005) for further taxonomic discussion.

Studies by Rausch and Rausch (1975) indicated that the population on St. George Island (L. t. nigripes) is best regarded as a subspecies, but some recent authors (but not Jones et al. 1992 or Musser and Carleton [in Wilson and Reeder 1993, 2005]) have continued to recognize nigripes as a distinct species.