| Canadian lemming | |
|---|---|
 | |
| Canadian lemming | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Cricetidae |
| Subfamily: | Arvicolinae |
| Genus: | Lemmus |
| Species: | L. trimucronatus |
| Binomial name | |
| Lemmus trimucronatus (Richardson, 1825) | |
 | |
| North American brown lemming range (includes range of L. nigripes ) [1] | |
The Canadian lemming or Nearctic brown lemming (Lemmus trimucronatus) is a small North American lemming.
The taxonomy of the Canadian lemming is tangled with the Siberian brown lemming and the Beringian lemming.
The Canadian lemming was formerly thought to be a subspecies of the Siberian brown lemming (Lemmus sibiricus), but those were split into two distinct species. They were still considered the same species as the Beringian lemming (Lemmus nigripes); the combined species was named the North American brown lemming with the scientific name L. trimucronatus, and was thought to range from eastern Siberia to North America. Recent phylogenetic studies showed them to also be distinct species, although sister groups to one another. [3] [4]
Lemmings are a brown in colour, with an reddish-brown back and rump, while the head and shoulders are grey. In the winter, the coat becomes longer and greyer. The female averages 12.5 cm (4.9 in) in length and weighs 58 g (2.0 oz), while the male averages 13 cm (5.1 in) and weighs 68 g (2.4 oz). Like other lemmings, it has small ears, short legs and a very short tail. The feet, both the soles and toes, are covered with bristles and are adapted for burrowing.
The lemming is found in the tundra areas of northern Canada (Nunavut, Northwest Territories, Yukon), and southern Alaska south of the Alaska Range. It is also found on the west coast of British Columbia almost as far south as Vancouver Island. Although this species was formerly thought to exist in eastern Siberia and most of Alaska, that species has now been found to be L. nigripes . [3]
They feed mainly on grass shoots and will also eat tundra grass, sedge, moss, bark, berries, lichens, and roots. Predators include most carnivores and certain birds, and some evidence suggests caribou may sometimes eat them. In years when the brown lemming is scarce, some predators, such as the Arctic fox, may be unable to reproduce.
They live underground, in colonies, and may produce up to three litters each year, including under the snow in winter. With a gestation period of 23 days, the female will give birth from four to nine young. The brown lemming is not migratory and when overpopulated (and during mating season), they will fight amongst themselves.
Bylot Island has several wetlands with shallow polygons and many types of mosses, grasses and sedges, which suits the North American brown lemming very well for several reasons (Rochefort et al. 1996). On Bylot Island they prefer to live in the South plain of the island and mostly live in the polygon fen, also known as wetlands, which mostly supports the graminoids that they rely on for food (Bety et al. 2002). During winter brown lemmings live in insulated burrows in the ground made out of sedges and grasses (Reid et al. 2011). They make their nests in these confined burrows underground because it increases insulation and allows them to reproduce during winter (Duchesne et al. 2011). Studies on Bylot Island have shown that brown lemmings prefer to burrow under increasing snow depth rather than more dense. They believe that brown lemmings do this because the more snow depth the better energy is trapped and the number of nests increased. Deeper snow cover also protected lemmings and their nests from avian predators; mammalian predators can still forage for them but since their nests are so deep it decreases the ability of some predators to see, therefore, they are very well protected from predators (Duchesne et al. 2011; Reid et al. 2012). During summer, brown lemmings do not have the cover of snow and their territories become a lot more widespread across Bylot Island (Reid et al. 2012).
The Arctic fox, also known as the white fox, polar fox, or snow fox, is a small species of fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in cold environments, and is best known for its thick, warm fur that is also used as camouflage. It has a large and very fluffy tail. In the wild, most individuals do not live past their first year but some exceptional ones survive up to 11 years. Its body length ranges from 46 to 68 cm, with a generally rounded body shape to minimize the escape of body heat.
The snowy owl, also known as the polar owl, the white owl and the Arctic owl, is a large, white owl of the true owl family. Snowy owls are native to the Arctic regions of both North America and the Palearctic, breeding mostly on the tundra. It has a number of unique adaptations to its habitat and lifestyle, which are quite distinct from other extant owls. One of the largest species of owl, it is the only owl with mainly white plumage. Males tend to be a purer white overall while females tend to have more extensive flecks of dark brown. Juvenile male snowy owls have dark markings that may appear similar to females until maturity, at which point they typically turn whiter. The composition of brown markings about the wing, although not foolproof, is the most reliable technique to age and sex individual snowy owls.
Bylot Island lies off the northern end of Baffin Island in Nunavut Territory, Canada. Eclipse Sound to the southeast and Navy Board Inlet to the southwest separate it from Baffin Island. Parry Channel lies to its northwest. At 11,067 km2 (4,273 sq mi) it is ranked 71st largest island in the world and Canada's 17th largest island. The island measures 180 km (110 mi) east to west and 110 km (68 mi) north to south and is one of the largest uninhabited islands in the world. While there are no permanent settlements on this Canadian Arctic island, Inuit from Pond Inlet and elsewhere regularly travel to Bylot Island. An Inuit seasonal hunting camp is located southwest of Cape Graham Moore.
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae. Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea. Some refer to the subfamily as the Microtinae or rank the taxon as a full family, the Arvicolidae.
The Norway lemming, also known as the Norwegian lemming is a common species of lemming found in northern Fennoscandia, where it is the only vertebrate species endemic to the region. The Norway lemming dwells in tundra and fells, and prefers to live near water. Adults feed primarily on sedges, grasses and moss. They are active at both day and night, alternating naps with periods of activity.
The northern bog lemming is a small North American lemming. It is one of two species in the genus Synaptomys, the other being the southern bog lemming. It is sometimes placed in its own genus, Mictomys.
The Ungava collared lemming or Labrador collared lemming is a small North American lemming.
The Richardson's collared lemming is a small North American lemming. At one time, they were considered to be a subspecies of the Arctic lemming, Dicrostonyx torquatus. Some sources believe they are a subspecies of the northern collared lemming, Dicrostonyx groenlandicus.
The northern collared lemming or Nearctic collared lemming, sometimes called the Peary Land collared lemming in Canada, is a small lemming found in Arctic North America and Wrangel Island. At one time, it was considered to be a subspecies of the Arctic lemming. Some sources believe several other species of collared lemmings found in North America are actually subspecies of D. groenlandicus.
The genus Lemmus contains several species of lemming sometimes referred to as the true lemmings. They are distributed throughout the Holarctic, particularly in the Palearctic.
The grey red-backed vole or the grey-sided vole is a species of vole. An adult grey red-backed vole weighs 20-50 grams. This species ranges across northern Eurasia, including northern China, the northern Korean Peninsula, and the islands of Sakhalin and Hokkaidō. It is larger and longer-legged than the northern red-backed vole, which covers a similar range and it is also sympatric with the Norwegian lemming.
The Arctic lemming is a species of rodent in the family Cricetidae.
The WestSiberian lemming or Western Siberian brown lemming is a true lemming species found in the Russian Federation. Like other lemmings, it belongs to the Cricetidae family of rodents.
Promise Island is located near the western shore of Hudson Bay. It is barely a square kilometre in area and rises 300 ft (91 m) in elevation on its northern side. It is located about 9 km (5.6 mi) from the community of Chesterfield Inlet, Nunavut, Canada, and is part of a loose chain of small islands running along the coast, including the Wag Islands and Pitsiulartok.
A lemming is a small rodent, usually found in or near the Arctic in tundra biomes. Lemmings form the subfamily Arvicolinae together with voles and muskrats, which form part of the superfamily Muroidea, which also includes rats, mice, hamsters, and gerbils. In popular culture, a longstanding myth holds that they exhibit herd mentality and jump off cliffs, committing mass suicide.
The Canadian Arctic tundra is a biogeographic designation for Northern Canada's terrain generally lying north of the tree line or boreal forest, that corresponds with the Scandinavian Alpine tundra to the east and the Siberian Arctic tundra to the west inside the circumpolar tundra belt of the Northern Hemisphere.
The Canadian Low Arctic Tundra ecoregion covers a rolling landscape of shrubby tundra vegetation along the northern edge of the mainland Canada along the border of the Northwest Territories and Nunavut, and a small portion in Quebec on the northeast coast of Hudson Bay. The region is important for large herds of caribou and other large mammals, and for large nesting colonies of birds such as snow geese. The region is mostly intact, with 95% remaining intact.
The Canadian Middle Arctic Tundra ecoregion covers a broad stretch of northern Canada - the southern islands of the Arctic Archipelago, plus the northern mainland of Nunavut and, across Hudson Bay to the east, a portion of northern Quebec. This is the coldest and driest ecoregion in Canada, and can be referred to as a 'polar desert'. It is an important region for breeding and migratory birds, and supports 80% of the world's muskox.
The Beringian lemming or Beringian brown lemming is a species of lemming found in Russia and North America.
