北极熊英文介绍

北极熊是世界上最大的陆地食肉动物，又名白熊。按动物学分类属哺乳纲，熊科。雄性北极熊身长大约240-260cm，体重一般为400-800公斤。而雌性北极熊体形约比雄性小一半左右，身长约190-210cm，体重约200-300公斤。到了冬季睡眠时刻到来之前，由于脂肪将大量积累，它们的体重可达800公斤。北极熊的视力和听力与人类相当，但它们的嗅觉极为灵敏，是犬类的7倍，时速可达60公里，是世界百米冠军的1.5倍

The polar bear (Ursus maritimus) is a bear native to the Arctic Ocean and its surrounding seas.The world's largest predator found on land,an adult male weighs around 400–680 kg (880–1,500 lb),while an adult female is about half that size.Although it is closely related to the brown bear,it has evolved to occupy a narrow 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.As it can hunt consistently only from sea ice,the polar bear spends much of the year on the frozen sea,although most polar bears are born on land. The polar bear is classified as a vulnerable species.Of the 19 recognized polar bear subpopulations,5 are declining,5 are stable,2 are increasing,and 7 have insufficient data.For decades,unrestricted hunting raised international concern for the future of the species; populations have rebounded after controls and quotas began to take effect.For thousands of years,the polar bear has been a key figure in the material,spiritual,and cultural life of Arctic indigenous peoples,and the hunting of polar bears remains important in their cultures. The IUCN now lists global warming as the most significant threat to the polar bear,primarily because the melting of its sea ice habitat reduces its ability to find sufficient food.Sea ice melting will also cause changes in their mating,and traveling patterns.The IUCN states,"If climatic trends continue polar bears may become extirpated from most of their range within 100 years." On May 14,2008,the United States Department of the Interior listed the polar bear as a threatened species under the Endangered Species Act.

The polar bear is the largest animal in the bear family, body length of up to 2.5 meters, 1.6 meters high, weighing 500 kg. Polar bearsare not only good at swimming in cold water, but also good at quick jump on the ice, the maximum can reach a height of 1.8 metres. As the "king of the Arctic Circle", except for humans, bears almost no natural enemies.希望采纳! 北极熊是熊科动物中最大的,体长可达2.5米,高1.6米,重500公斤.北极熊不仅善于在冰冷的海水中游泳,还擅长在冰面上快速跳跃,最高可以达到1.8米的高度.作为“北极圈之王”,除去人类,北极熊几乎没有天敌