Brown lemmings are found in the tundra regions of Siberia and North America. They can be found in arctic tundra and in subarctic alpine tundra above treeline.
(Jarrell & Fredga, 1993; Rodgers & Lewis, 1986; Stenseth & Ims, 1993c; Wilson & Ruff, 1999)
Brown lemmings live in northern treeless regions, usually in low-lying, flat meadow habitats dominated by graminoids and mosses. In summer, they live in areas rich in grasses and sedges, moving in winter to mossy areas with permanent snow cover or wet meadows. (Barkley et al., 1980; Rodgers & Lewis, 1985; Stenseth & Ims, 1993c; Wilson & Ruff, 1999)
Brown lemmings have stout bodies which do not appear as elongated as other microtine rodents. Total body length is 130-180mm, averaging 150mm. Sexes are similar in size, though males are 5-10% larger than females. They have small eyes, small ears hidden under the fur, blunt muzzles, and short tails (18-26mm, averaging 21mm, including hair at the tip). Their backs and sides are tawny brown to cinnamon, with a paler underbelly; unlike some other lemming species (e.g. most species of the genus Dicrostonyx), they do not change colour in the winter. Older adults may have a rusty-coloured patch on the rump.
(Stenseth & Ims, 1993c; Wilson & Ruff, 1999)
Brown lemmings become sexually mature quite early, normally at 5-6 weeks of age, but possibly as early as 3 weeks in some summers. Females can breed immediately after giving birth (post-partum estrus). They give birth to 2-13 young, after a 3 week gestation period. Litter size averages 8 in summer, 4 to 5 in early and late winter, and 3 in mid-winter. There appears to be no reproduction during the spring snow melt (May through early June) nor during the fall snow pack formation (September through early October).
Not much is known about their reproductive habits, but it is likely that females rear the young alone, since no males have been caught in a wild nest with young. Non-receptive captive females have been known to attack males. It is also likely that breeding is promiscuous, since males have larger home ranges than females, and there is substantial overlap in the home ranges of multiple individuals.
(Stenseth & Ims, 1993a; Wilson & Ruff, 1999)
Brown lemmings are mainly solitary, defending separate individual territories consisting of underground burrow systems dug into the tundra soil or snow cover. Territories may overlap extensively in a given area, but individual animals of both sexes tend to avoid each other except for reproduction.
(Henttonen & Kaikusalo, 1993; Rodgers & Lewis, 1986; Stenseth & Ims, 1993b; Wilson & Ruff, 1999)
Brown lemmings eat only live plant parts. For most of the year, they eat fresh grasses, sedges, and mosses (except sphagnum). In summer in areas of wet tundra, their diet consists primarily of monocot leaves, making up 76 to 90%. In winter they eat frozen (but still green) plant material, the available 1-2cm of basal leaf sheaths, and moss shoots. Mosses can make up nearly one-half of their winter diet, and are also important in dry tundra, where mosses make up about 30% of their diet.
Because their food is so low in nutrients, they must eat quite a lot of it; they forage for 1-2 hours at a time, at roughly 3-hour intervals, throughout the 24-hour day.
(Barkley et al., 1980; Batzli, 1993; Wilson & Ruff, 1999)
No information available.
No information available.
Although there is no recognized, immediate threat to the global population of brown lemmings, they are in danger of decline in years to come. The predicted warming of the Canadian climate, and predicted northward migration of Canadian biota, may result in a reduction of the range of the brown lemming, which is limited in the north by the Arctic Ocean. Brown lemmings are quite inflexible in such traits as diet and preferred terrain, so they would be particularly sensitive to such a loss of habitat.
(Kerr & Packer, 1998)
Jennifer Barker (author), University of Toronto.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.
Barkley, S., G. Batzli, B. Collier. 1980. Nutritional ecology of microtine rodents: a simulation of mineral nutrition for brown lemmings. Oikos, 34: 103-114.
Batzli, G. 1993. Food selection by lemmings. Pp. 281-301 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego: Academic Press.
Henttonen, H., A. Kaikusalo. 1993. Lemming movements. Pp. 157-186 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Jarrell, G., K. Fredga. 1993. How many kinds of lemmings? A taxonomic overview. Pp. 45-57 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Kerr, J., L. Packer. 1998. The impact of climate change on mammal diversity in Canada. Environmental Monitoring and Assessment, 49: 263-270.
Pitelka, F., G. Batzli. 1993. Distribution, abundance and habitat use by lemmings on the north slope of Alaska. Pp. 213-236 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Rodgers, A., M. Lewis. 1986. Diet selection in Arctic lemmings (Lemmus sibiricus and Dicrostonyx groenlandicus): demography, home range, and habitat use. Can. J. Zool., 64: 2717-2727.
Stenseth, N., R. Ims. 1993a. Food selection, individual growth and reproduction - an introduction. Pp. 263-280 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Stenseth, N., R. Ims. 1993b. Intra and interspecific relations - an introduction. Pp. 341-354 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Stenseth, N., R. Ims. 1993d. Population dynamics of lemmings: temporal and spatial variation - an introduction. Pp. 61-96 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Stenseth, N., R. Ims. 1993c. The evolutionary history and distribution of lemmings - an introduction. Pp. 37-43 in N Stenseth, R Ims, eds. The biology of lemmings. San Diego, CA: Academic Press.
Wilson, D., S. Ruff. 1999. The Smithsonian book of North American mammals. Vancouver: UBC Press.