Perception Channels: tactile ; chemical
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)
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
No information available.
No information available.
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)
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)
Biogeographic Regions: nearctic (Native ); palearctic (Native )
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)
Terrestrial Biomes: tundra
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)
Range mass: 45 to 130 g.
Average mass: 80 g.
Other Physical Features: endothermic ; bilateral symmetry
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)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
The East Siberian lemming, Eastern Siberian brown lemming, or Ognev's lemming (Lemmus paulus) is a species of lemming endemic to Russia, where it has a disjunct distribution throughout parts of Siberia east of the Verkhoyansk Range.
It was formerly thought conspecific with the West Siberian lemming (L. sibiricus), which replaces it west of the Verkhoyansk Range, with both species being previously classified together as the Siberian brown lemming. Some populations were also previously classified as populations of the Amur lemming (L. amurensis). More recent genetic studies found both the eastern L. sibiricus and the northern L. amurensis to together represent a distinct species from either species.[1][2] The results of these studies were accepted by the American Society of Mammalogists.[3]
There are several disjunct populations; one is found from the Verkhoyansk Range east to the Kolyma River, including the New Siberian Islands; it is largely replaced by the Beringian lemming (L. nigripes) east of this region.
Another population is found south of the aforementioned northern population, being distributed from southern Yakutia and western Khabarovsk north to Magadan; this population was formerly classified as a subspecies of the Amur lemming, L. a. ognevi, or as its own distinct species, L. ognevi. Another population is found throughout most of the Kamchatka Peninsula (this population was also formerly classified as a subspecies of the Amur lemming, L. a. flavescens, or as its own distinct species, L. flavescens) although a disjunct population of L. nigripes is also present in the southern section of the peninsula.[1]
Finally, an isolated population is present on Wrangel Island. This population was previously included as a subspecies of L. sibiricus by Jarrell and Fredga in 1993, while Chernyavskii (also in 1993) regarded it as a separate species, L. portenkoi. However, phylogenetic studies support it being a population of L. paulus.[4]
The East Siberian lemming, Eastern Siberian brown lemming, or Ognev's lemming (Lemmus paulus) is a species of lemming endemic to Russia, where it has a disjunct distribution throughout parts of Siberia east of the Verkhoyansk Range.
