Lemmings are small rodents that live in treeless areas of northern Canada. Their bodies are well adapted to the cold conditions they live in; they have a very thick coat of fur in the winter, short ears, short legs, and short tails. Adult lemmings are about 150 mm in total length, including about 20 mm of tail. Their body weight varies from about 55 g in some years to about 115 g in others.
There are two types of lemming found in the Canadian Arctic. The brown lemming's fur is brown and grey summer and winter. Collared lemmings are the same overall size as brown lemmings. Their color changes with the seasons. In summer, a collared lemming has a black nose, grey cheeks, tawny ear spots, a chestnut collar, and a black stripe on its back. With the autumn molt, the summer coat is replaced by a solid white winter one and the front feet develop two greatly enlarged claws, to help dig in the hard-packed tundra snow.
The smallest of the mammals of the High Arctic, lemmings are key species in arctic ecosystems. Lemming populations fluctuate drastically, peaking about every four years and then crashing almost to extinction. Because the small bodies of lemmings are important food for ermines, arctic foxes, Snowy Owls, Gyrfalcons, and jaegers, this mysterious cycle controls the rhythm of animal life on the tundra.
Most lemmings live in areas with permafrost, or soil that is always frozen. This means that the lemmings are unable to dig deep burrows for shelter even in summer. Where the soil contains much water, however, seasonal freezing and thawing creates ridges and depressions that lemmings use for burrows and as travel routes.
Winter is a critical time for lemmings because, unlike many species of rodents, they do not hibernate. It is amazing that these small, warm-blooded animals remain active throughout the Arctic winter without freezing to death. As winter approaches, lemmings make large, nests of shredded grasses and sedges on the surface of the ground, which provide additional insulation when they are not out hunting for food. Snow provides important insulation. Lemmings forage in the space that forms between soil and snow, known as subnivean space, almost never appearing on the surface. In the High Arctic, temperatures in this subnivean space are not exactly warm, but they are better than those above the snow, and the difference is a key to lemming survival.
Lemmings are a vital part of the web of life on the tundra, and they help to teach us how intricate even that simple ecosystem is. Their burrowing changes the arctic soil. Their feeding habits influence the composition of the plant community on the tundra. Lemmings are also food for many tundra animals. Animals like the Arctic Fox and Snowy Owl depend on the lemming for their survival.
Links about Lemmings:
http://en.wikipedia.org/wiki/Lemming
http://www.hww.ca/hww2.asp?id=91
The smallest of the mammals of the High Arctic, lemmings are key species in arctic ecosystems. Lemming populations fluctuate drastically, peaking about every four years and then crashing almost to extinction. Because the small bodies of lemmings are important food for ermines, arctic foxes, Snowy Owls, Gyrfalcons, and jaegers, this mysterious cycle controls the rhythm of animal life on the tundra.
Most lemmings live in areas with permafrost, or soil that is always frozen. This means that the lemmings are unable to dig deep burrows for shelter even in summer. Where the soil contains much water, however, seasonal freezing and thawing creates ridges and depressions that lemmings use for burrows and as travel routes.
Winter is a critical time for lemmings because, unlike many species of rodents, they do not hibernate. It is amazing that these small, warm-blooded animals remain active throughout the Arctic winter without freezing to death. As winter approaches, lemmings make large, nests of shredded grasses and sedges on the surface of the ground, which provide additional insulation when they are not out hunting for food. Snow provides important insulation. Lemmings forage in the space that forms between soil and snow, known as subnivean space, almost never appearing on the surface. In the High Arctic, temperatures in this subnivean space are not exactly warm, but they are better than those above the snow, and the difference is a key to lemming survival.
Lemmings are a vital part of the web of life on the tundra, and they help to teach us how intricate even that simple ecosystem is. Their burrowing changes the arctic soil. Their feeding habits influence the composition of the plant community on the tundra. Lemmings are also food for many tundra animals. Animals like the Arctic Fox and Snowy Owl depend on the lemming for their survival.
Links about Lemmings:
http://en.wikipedia.org/wiki/Lemming
http://www.hww.ca/hww2.asp?id=91
The lemming is so cute and so small. It looks like a mouse almost. The color is very cool to.
they are so cute. they look like little mice