Ursus maritimus
8. Polar Bear Ursus maritimus French: Ours blanc / German: Eisbar / Spanish: Oso polar Other common names: \White Bear, Nanook Taxonomy. Ursus maritimus Phipps, 1774, Spitsbergen, (Svalbard) Norway. Considered a sister species to U. arctos. Most closely related to Brown Bears on the Admiralty, Baran...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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Lynx Edicions
2009
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| Online Access: | https://doi.org/10.5281/zenodo.5714783 http://treatment.plazi.org/id/039D8794F660C76A95CD786DF94FFD51 |
| Summary: | 8. Polar Bear Ursus maritimus French: Ours blanc / German: Eisbar / Spanish: Oso polar Other common names: \White Bear, Nanook Taxonomy. Ursus maritimus Phipps, 1774, Spitsbergen, (Svalbard) Norway. Considered a sister species to U. arctos. Most closely related to Brown Bears on the Admiralty, Baranof, Chichagof islands of south-east Alaska. Although several distinct populations or stocks have been delineated, small genetic differences have been found among these, and no subspecies have been differentiated. Monotypic. Distribution. Arctic Ocean: Canada, USA (Alaska), Greenland, Norway (Svalbard), Russia. Have been sighted within 0-5° of North Pole. Descriptive notes. Head-body 180-280 cm, shoulder height up to 170 cm,tail 6-13 cm; adult males are about twice as heavy (300-650 kg, but up to 800 kg) as adult females (150-250 kg, but up to 500 kg when pregnant), making them one of the most sexuallydimorphic mammals. Size varies regionally, being smallest in eastern Greenland, and progressively larger westward to the Bering Sea. Facial profile is straight, the neck is longer than in other bears, and the ears are small in relation to head and body size. Coat color appears white or yellowish, with no other markings, but can accumulate colors from the environment (e.g. blood and oils from killed prey). In reality, both guard hairs and underfur are translucent, and guard hairs are hollow, thus enhancing their insulation properties. However, a previous assertion that they act as fiber optic tubes, funneling sunlight to the skin for warmth, has been disproven. The skin is black, but only the black nose is visible. Summer coats are shorter than winter coats, but unlike other bears, coat thickness is not sparser ventrally. Additionally, the paws are well-furred on the underside, and have small soft papillae and vacuoles that may act as suction cups for traction on ice. The feet are also relatively large, providing more surface area for swimming and walking on thin ice. The claws are shorter and more curved than Brown Bears, ... |
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