The polar bear (''Ursus maritimus'') is a carnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (''Ursus arctos middendorffi''). A boar (adult male) weighs around , while a sow (adult female) is about half that size. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, they spend most of their time at sea. Their scientific name means "maritime bear", and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present.
The polar bear is classified as a vulnerable species, with eight of the nineteen polar bear subpopulations in decline.〔IUCN Polar Bear Specialist Group, 2009.(15th meeting of PBSG in Copenhagen, Denmark 2009: Press Release ). Retrieved 10 January 2010.〕 For decades, large scale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to take effect.〔("Why is polar bear hunting allowed?" ). Retrieved July 8, 2015.〕 For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous peoples, and polar bears remain important in their cultures.
==Naming and etymology==
Constantine John Phipps was the first to describe the polar bear as a distinct species in 1774.〔 He chose the scientific name ''Ursus maritimus'', the Latin for 'maritime bear', due to the animal's native habitat. The Inuit refer to the animal as ''nanook'' (transliterated as ''nanuq'' in the Inupiat language).〔(The Arctic Sounder )〕 The Yupik also refer to the bear as ''nanuuk'' in Siberian Yupik.〔Hall, Sam (1988) ''The fourth world: the heritage of the Arctic and its destruction'', Vintage Books, ISBN 0394559428, pp. 29, 232.〕 The bear is ''umka'' in the Chukchi language. In Russian, it is usually called бе́лый медве́дь (''bélyj medvédj'', the white bear), though an older word still in use is ошку́й (''Oshkúj'', which comes from the Komi ''oski'', "bear"). In French, the polar bear is referred to as ''ours blanc'' ("white bear") or ''ours polaire'' ("polar bear").〔(【引用サイトリンク】title=Grand Quebec )〕 In the Norwegian-administered Svalbard archipelago, the polar bear is referred to as ''Isbjørn'' ("ice bear").
The polar bear was previously considered to be in its own genus, ''Thalarctos''.〔This combines the Ancient Greek words ''thalassa''/θαλασσα 'sea', and ''arctos''/αρκτος 'bear' and also, with reference to Ursa Major, 'northern' or 'of the north pole' 〕 However, evidence of hybrids between polar bears and brown bears, and of the recent evolutionary divergence of the two species, does not support the establishment of this separate genus, and the accepted scientific name is now therefore ''Ursus maritimus'', as Phipps originally proposed.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
| 翻訳と辞書 : 翻訳のためのインターネットリソース|
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.