Richardson's Collared Lemming
Encyclopedia
The Richardson's Collared Lemming, Dicrostonyx richardsoni is a small North America
n lemming
. At one time, they were considered to be a subspecies of the Arctic Lemming
, Dicrostonyx torquatus. Some sources believe that they are a subspecies of the Northern Collared Lemming
, Dicrostonyx groenlandicus.
They have short chunky bodies covered with grizzled brown fur which varies from red-brown to grey-brown with a thin dark stripe along their back and a reddish grey belly. They have small ears, short legs and a very short tail. They have a reddish collar across their chest. In winter, they are covered with white fur and they develop enlarged digging claws on their front feet. They are 13 cm long with a 1 cm tail and weigh about 60 g.
These animals are found in the tundra
west of Hudson Bay
in north central Canada
. They feed on grasses, sedges and other green vegetation in summer and twigs of willow
, aspen
and birch
es in winter. Predators include Snowy Owl
s, mustelids and Arctic Fox
es.
Female lemmings have 2 or 3 litters of 4 to 8 young in a year. The young are born in a nest in an underground burrow or concealed in vegetation.
They are active year round, day and night. They make runways through the surface vegetation and also dig underground burrows above the permafrost
. They burrow under the snow in winter. Lemming populations go through a 3 or 4 year cycle of boom and bust. When their population peaks, lemmings disperse from overcrowded areas.
This animal was named after Sir John Richardson
, a Scottish
naturalist who explored the Canadian Arctic.
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n lemming
Lemming
Lemmings are small rodents, usually found in or near the Arctic, in tundra biomes. They are subniveal animals, and together with voles and muskrats, they make up the subfamily Arvicolinae , which forms part of the largest mammal radiation by far, the superfamily Muroidea, which also includes rats,...
. At one time, they were considered to be a subspecies of the Arctic Lemming
Arctic Lemming
The Arctic Lemming is a species of rodent in the family Cricetidae.It is found only in The Arctic Biomes in Russia and Canada.-References:...
, Dicrostonyx torquatus. Some sources believe that they are a subspecies of the Northern Collared Lemming
Northern Collared Lemming
The Northern Collared Lemming , sometimes called the Peary Land Collared Lemming in Canada, is a small North American lemming. At one time, it was considered to be a subspecies of the Arctic Lemming...
, Dicrostonyx groenlandicus.
They have short chunky bodies covered with grizzled brown fur which varies from red-brown to grey-brown with a thin dark stripe along their back and a reddish grey belly. They have small ears, short legs and a very short tail. They have a reddish collar across their chest. In winter, they are covered with white fur and they develop enlarged digging claws on their front feet. They are 13 cm long with a 1 cm tail and weigh about 60 g.
These animals are found in the tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
west of Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
in north central Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. They feed on grasses, sedges and other green vegetation in summer and twigs of willow
Willow
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
, aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
and birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
es in winter. Predators include Snowy Owl
Snowy Owl
The Snowy Owl is a large owl of the typical owl family Strigidae. The Snowy Owl was first classified in 1758 by Carolus Linnaeus, the Swedish naturalist who developed binomial nomenclature to classify and organize plants and animals. The bird is also known in North America as the Arctic Owl, Great...
s, mustelids and Arctic Fox
Arctic fox
The arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...
es.
Female lemmings have 2 or 3 litters of 4 to 8 young in a year. The young are born in a nest in an underground burrow or concealed in vegetation.
They are active year round, day and night. They make runways through the surface vegetation and also dig underground burrows above the permafrost
Permafrost
In geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...
. They burrow under the snow in winter. Lemming populations go through a 3 or 4 year cycle of boom and bust. When their population peaks, lemmings disperse from overcrowded areas.
This animal was named after Sir John Richardson
John Richardson (naturalist)
Sir John Richardson was a Scottish naval surgeon, naturalist and arctic explorer.Richardson was born at Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of...
, a Scottish
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
naturalist who explored the Canadian Arctic.