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True Lemming
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. Description Head and body is 10-13.5 cm, and tail length is 18–26 mm. Weight ranges from 40-112 g. They are grey or brown. Unlike the collared lemmings, their coats do not change color in winter. They stay brown and grey. Natural history These lemmings are found predominantly in tundra or high elevations. Populations can fluctuate widely and mass migrations do take place. This mass migration is probably the source of the myth that lemmings commit mass suicide. These intense population booms appear to be most common in the northern part of its range (such as Sápmi (area), Lapland). Gestation is 16–23 days. Litters are 1-13 (7 average). Young are sexually mature after 14 days. When conditions are favorable, these demography, demographic parameters allow for a veritable explosion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 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 grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Siberian region; the Mediterranean Basin; the Sahara and Arabian Deserts; and Western, Central and East Asia. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions. The term 'Palearctic' was first used in the 19th century, and is still in use as the basis for zoogeographic classification. History In an 1858 paper for the ''Proceedings of the Linnean Society'', British zoologist Philip Sclater first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/Afrotropic, Indian/Indomalayan, Australasian, Nearctic, and Neotropical. The six indicated general groupings of fauna, based on shared biogeography and large-scale geographic barriers to migration. Alfred Wallace a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Siberian Lemming
The West Siberian lemming or Western Siberian brown lemming (''Lemmus sibiricus'') is a true lemming species found in the Russian Federation. Like other lemmings, it belongs to the Cricetidae family of rodents. It is endemic to Russia, where it has a wide range throughout Siberia, from the region just south of the White Sea east all the way to the Verkhoyansk Range, which serves as a barrier between it and the East Siberian lemming (''L. paulus''), which was formerly considered conspecific with it. An insular population inhabits Novaya Zemlya; a 2021 study which performed genetic analysis on the mtDNA of the Novaya Zemlya population found them to group with the Norway lemming (''L. lemmus'') despite their similar appearance to mainland ''L. sibiricus'', and classified them as the subspecies ''L. l. chernovi'', or Novaya Zemlya lemming. However, the American Society of Mammalogists rejected these results pending further evidence, stating that these more likely represented ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Siberian Lemming
The East Siberian lemming, Eastern Siberian brown lemming, or Ognev's lemming (''Lemmus paulus'') is a species of lemming endemic to Russia, where it has a disjunct distribution throughout parts of Siberia east of the Verkhoyansk Range. Taxonomy It was formerly thought conspecific with the West Siberian lemming (''L. sibiricus''), which replaces it west of the Verkhoyansk Range, with both species being previously classified together as the Siberian brown lemming. Some populations were also previously classified as populations of the Amur lemming (''L. amurensis''). More recent genetic studies found both the eastern ''L. sibiricus'' and the northern ''L. amurensis'' to together represent a distinct species from either species. The results of these studies were accepted by the American Society of Mammalogists. Distribution There are several disjunct populations; one is found from the Verkhoyansk Range east to the Kolyma River, including the New Siberian Islands; it is largely r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beringian Lemming
The Beringian lemming or Beringian brown lemming (''Lemmus nigripes'') is a species of lemming found in Russia and North America. Taxonomy It was formerly considered conspecific with the Canadian lemming (''L. trimucronatus'') with both species being grouped together as the "North American brown lemming", but genetic studies have affirmed both as being distinct species from one another. Distribution This species is found on both sides of the Bering Sea, and its distribution roughly coincides with the former landmass of Beringia, which it likely inhabited prior to its partial submergence. In Siberia, it is found east of the Kolyma River (with the East Siberian lemming, ''L. paulus'', being found west of the river) ranging throughout most of Chukotka, northern Magadan, and northern Kamchatka Krai. A disjunct population is also present in the southern Kamchatka Peninsula, which is otherwise inhabited only by ''L. paulus''. In North America, it is found throughout most of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amur Lemming
The Amur lemming (''Lemmus amurensis'') is a species of lemmings found near the Amur River in Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of .... References Lemmus Endemic fauna of Russia Rodents of Asia Mammals described in 1924 {{Arvicolinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demography
Demography () is the statistics, statistical study of populations, especially human beings. Demographic analysis examines and measures the dimensions and Population dynamics, dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of Social actions, social actors can change across time through processes of birth, death, and Human migration, migration. In the context of human biological populations, demographic analysis uses Public records, administrative records to develop an independent Approximation, estimate of the population. Demographic analysis estimates are often considered a reliable stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sápmi (area)
(, smj, Sábme / Sámeednam, sma, Saepmie, sju, Sábmie, , , sjd, Са̄мь е̄ммьне, Saam' jiemm'n'e) is the cultural region traditionally inhabited by the Sámi people. Sápmi is in Northern and Eastern Europe and includes the northern parts of Fennoscandia, also known as the "Cap of the North". The region stretches over four countries: Norway, Sweden, Finland, and Russia. On the north it is bounded by the Barents Sea, on the west by the Norwegian Sea, and on the east by the White Sea."Lapland." Encyclopædia Britannica. ''Encyclopædia Britannica Online. Encyclopædia Britannica'', 2009. Web. 24 November 2009 http://search.eb.com/eb/article-9047170. The area is historically referred to as Lapland () in English, although the term "Lapp" for its inhabitants is now considered pejorative.; ; Norwegian Sápmi was historically called ''Finnmǫrk'', a name used for the former county Finnmark, now Troms og Finnmark. Sápmi refers to the areas where the Sámi people h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Suicide
Mass suicide is a form of suicide, occurring when a group of people simultaneously kill themselves. Overview Mass suicide sometimes occurs in religious settings. In war, defeated groups may resort to mass suicide rather than being captured. Suicide pacts are a form of mass suicide that are sometimes planned or carried out by small groups of depressed or hopeless people. Mass suicides have been used as a form of political protest. Attitudes towards mass suicide change according to place and circumstance. People who resort to mass suicide rather than submit to what they consider intolerable oppression sometimes become the focus of a heroic myth. Such mass suicides might also win the grudging respect of the victors. On the other hand, the act of people resorting to mass suicide without being threatened – especially, when driven to this step by a charismatic religious leader, for reasons which often seem obscure – tends to be regarded far more negatively. Historical mass suic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collared Lemming
''Dicrostonyx'' is a genus of rodent in the family Cricetidae. It contains the collared lemmings. They are the only North American rodents that turn completely white in winter. It contains the following species: * 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 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 habita ... (''Dicrostonyx unalascensis'') References Dicrostonyx Taxa named by C. L. Gloger Taxonomy articles created by Polbot {{Arvicolinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holarctic
The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical region (which covers most of North America), and Alfred Wallace's Palearctic zoogeographical region (which covers North Africa, and all of Eurasia except for Southeast Asia, the Indian subcontinent, the southern Arabian Peninsula). These regions are further subdivided into a variety of ecoregions. Many ecosystems and the animal and plant communities that depend on them extend across a number of continents and cover large portions of the Holarctic realm. This continuity is the result of those regions’ shared glacial history. Major ecosystems Within the Holarctic realm, there are a variety of ecosystems. The type of ecosystem found in a given area depends on its latitude and the local geography. In the far north, a band of Arctic tundra en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
