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Collared Lemming
''Dicrostonyx'' is a genus of rodent in the family Cricetidae. It contains the collared lemmings or varying lemmings. They are the only North American rodents that turn completely white in winter. It contains the following species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...: * Northern collared lemming (''Dicrostonyx groenlandicus'') * Ungava collared lemming (''Dicrostonyx hudsonius'') * Nelson's collared lemming (''Dicrostonyx nelsoni'') * Ogilvie Mountains collared lemming (''Dicrostonyx nunatakensis'') * Richardson's collared lemming (''Dicrostonyx richardsoni'') * Arctic lemming (''Dicrostonyx torquatus'') * Unalaska collared lemming (''Dicrostonyx unalascensis'') References Dicrostonyx Taxa named by C. L. Gloger Taxonomy articles created by Polbot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unalaska Collared Lemming
The Unalaska collared lemming (''Dicrostonyx unalascensis'') is a species of rodent in the family Cricetidae. This species is found on two islands, Umnak and Unalaska, in the Aleutian Archipelago of Alaska in the United States. Its natural habitat is tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic .... References *Musser, G. G. and M. D. Carleton. (2005). Superfamily Muroidea. pp. 894–1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. Dicrostonyx Endemic rodents of the United States Endemic fauna of Alaska Umnak Unalaska Island Mammals described in 1900 Taxonomy articles created by Polbot Taxa named by Clinton Hart Merriam {{Arvicolinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Lemming
The Arctic lemming (''Dicrostonyx torquatus'') is a species of rodent in the family Cricetidae. Although generally classified as a "least concern" species, the Novaya Zemlya subspecies ''(Dicrostonyx torquatus ungulatus)'' is considered a vulnerable species under Russian nature conservation legislation (included in Red Book of Russian Federation since 1998). Biology It is found only in the Arctic biomes in the Russian Federation, and it is the most common mammal on Severnaya Zemlya. Specimens were once found in England, but they are now extirpated. For the most part, lemmings of the genus ''Lemmus'' can coexist with those of genus ''Dicrostonyx''. Arctic lemmings migrate when population density becomes too great, and they resort to swimming in search of a new habitat. The disappearance of lemmings and the lemming cycles in the Arctic have shown that they are the causes of fluctuations in local breeding among geese and waders. Recovery of lemmings after years of low density is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richardson's Collared Lemming
The Richardson's collared lemming (''Dicrostonyx richardsoni'') 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''. This species has a short, chunky body covered with grizzled brown fur, which varies from red-brown to grey-brown, with a thin dark stripe along its back and a reddish-grey belly. It has small ears, short legs and a very short tail, and a reddish collar across its chest. In winter, it is covered with white fur, and develops enlarged digging claws on its front feet. It is about 13 cm long with a 1 cm tail, and weighs 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 birches in winter. Predators include snowy owls, musteli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ogilvie Mountains Collared Lemming
The Ogilvie Mountains collared lemming (''Dicrostonyx nunatakensis'') is a species of rodent in the family Cricetidae. It is found only in Yukon Territory, Canada.Musser, G. G. and M. D. Carleton. (2005). Superfamily Muroidea. Pp. 894-1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. Its natural habitat is tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic .... References Dicrostonyx Rodents of Canada Endemic fauna of Canada Endemic fauna of Yukon Mammals described in 1967 Taxonomy articles created by Polbot {{Arvicolinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nelson's Collared Lemming
Nelson's collared lemming (''Dicrostonyx nelsoni'') is a species of rodent in the family Cricetidae. It is found in western and southwestern Alaska in the United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 .... References See also *Musser, G. G., and M. D. Carleton. (2005). Superfamily Muroidea. pp. 894–1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. Dicrostonyx Mammals described in 1900 Arctic land animals Endemic rodents of the United States Endemic fauna of Alaska Mammals of the Arctic Taxonomy articles created by Polbot Taxa named by Clinton Hart Merriam {{Arvicolinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungava Collared Lemming
The Ungava collared lemming or Labrador collared lemming (''Dicrostonyx hudsonius'') is a small North American lemming. This species has a short, chunky body covered with brownish-grey fur, with a thin dark stripe along the back and a yellow line along its sides. It has small ears, short legs and a very short tail, and a reddish collar across its chest and a reddish patch behind its ears. In winter, it is covered with white fur, and develops enlarged digging claws on its front feet. They average 14 cm long with a 1.5 cm tail, and weigh about 60 g. These animals are found in the tundra of northern Quebec and Labrador. They feed on grasses, sedges and other green vegetation in summer, and twigs of willow, aspen, and birches in winter. Predators include snowy owls, mustelids, and Arctic foxes. Females have two or three litters of four to eight young in a year. The young are born in a nest in a burrow or concealed in vegetation. They are active year-round, day an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Collared Lemming
The northern collared lemming or Nearctic collared lemming (''Dicrostonyx groenlandicus''), 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 (''Dicrostonyx torquatus''). Some sources believe several other species of collared lemmings found in North America are actually subspecies of ''D. groenlandicus''. Description It has a short chunky body covered with thick grey fur with a thin black stripe along its back and light grey underparts. It has small ears, short legs and a very short tail. It has a pale brown collar across its chest. In winter, its fur turns white, and it has large digging claws on its front feet. It is long with a tail and weighs about . Distribution and habitat It is found in the tundra of northern Canada, Alaska and Greenland. A disjunct population is also present on Wrangel Island in Siberia; this populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At over 870 species, it is either the largest or second-largest family of mammals, and has members throughout the Americas, Europe and Asia. Characteristics The cricetids are small mammals, ranging from just in length and in weight in the New World pygmy mouse up to and in the muskrat. The length of their tails varies greatly in relation to their bodies, and they may be either furred or sparsely haired. The fur of most species is brownish in colour, often with a white underbelly, but many other patterns exist, especially in the cricetine and arvicoline subfamilies. Like the Old World mice, cricetids are adapted to a wide range of habitats, from the high Arctic to tropical rainforests and hot deserts. Some are arboreal, with long balancing tails and other adaptations for climbing, while others ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
