The brown lemming is a tough, herbivorous rodent living in arctic conditions ranging from Russian tundra to Alaskan wilderness and Canadian plains. The brown lemming favors low-lying, wet habitats with plenty of plant life.
The brown lemming (Lemmus trimucronatus) is native to the United States and Canada bit is dispersed as far afield as Siberia. He has a chunky build and a short tail. The average length of the North American brown lemming is about 6 inches; average weight is around 3 ounces. His thick, fluffy fur ranges in color from a tawny brown to a lighter reddish-brown. As he ages, he may develop a rusty-red patch of fur on his back. His ears may be tiny, but he has long claws. In winter, the brown lemming develops a two-pronged claw on the the third and fourth fingers of each front foot, which he uses to shovel snow.
Habitat and Diet
This lemming typically lives in flat, treeless areas; he particularly likes meadow habitats with a healthy supply of mosses and graminoid grass types; these are grasses with a narrow stem at the base. He can't eat dry, dead grass, and this fact determines his need to change diet with the seasons. During summer he feeds on the sedges and rushes of these pastures; during winter, snow cover and excess water in these grassy pastures forces him to feed on moss, and occasionally on willow and birch tree bark. During winter he needs to spend more time feeding than in summer, otherwise he won't get enough nourishment. In summer, he lives underground and, like his vole relative, is a an expert tunneler. In winter he tends to nest above ground. The personal space he occupies is typically between 3.5 to 6 square yards.
Reproduction and Lifespan
A lemming's lifespan is relatively short: One year in the wild is average; in captivity, a lemming may live three years. The brown lemming's main reproductive seasons are during the Arctic summer months of June to August, and occasionally during winter, but never during Spring or Fall. Lemmings reach sexual maturity at 5 to 6 weeks but sometimes as early as 3 weeks. The female lemming gives birth to two to 13 babies in each litter, and her gestation period is three weeks, so she may have more than one litter within a breeding season. Potentially she may have three litters during her second summer breeding season, but she rarely has more than two, according to Hinterland Who's Who. Given her short life span, it is unlikely that she has more than two summer breeding seasons. The female raises her young by herself. It is likely that the male lemming is a promiscuous chap who mates far and wide, as his habitat range is larger than the female lemming's.
Conservation and Predators
The brown lemming population is healthy. The International Union for Conservation of Nature classifies the species as one of "Least Concern." However, naturalists predict that the brown lemming's future population status is under threat from climate change. For example, a warmer Canadian climate may force him north, but the Arctic ocean forms a boundary around the the lemmings' terrain. as a result, he'll lose living space. Added to this, the brown lemming is very much a creature of habit: his sensitivity to habitat and dietary changes potentially threaten his survival. His natural enemies are the snowy owl, the weasel and and the Arctic fox.
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