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elephant seal
Elephant seals are large, oceangoing earless seals in the genus ''Mirounga''. The two species, the northern elephant seal (''M. angustirostris'') and the southern elephant seal (''M. leonina''), were both hunted to the brink of extinction by the end of the 19th century, but numbers have since recovered.
The northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S., Canada and Mexico. The most northerly breeding location on the Pacific Coast is at Race Rocks, at the southern tip of Vancouver Island in the Strait of Juan de Fuca. The southern elephant seal is found in the Southern Hemisphere on islands such as South Georgia and Macquarie Island, and on the coasts of New Zealand, South Africa, and Argentina in the Peninsula Valdés, which is the fourth-largest elephant seal colony in the world. Fossils of an as yet unnamed species of ''Mirounga'' have been found in South Africa, and dated to the Miocene epoch.
Elephant seals breed annually and are seemingly faithful to colonies that have established breeding areas.〔http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000554〕
==Description==
Elephant seals take their name from the large proboscis of the adult male (bull), which resembles an elephant's trunk. The bull's proboscis is used in producing extraordinarily loud roaring noises, especially during the mating season. More importantly, however, the nose acts as a sort of rebreather, filled with cavities designed to reabsorb moisture from the animals' exhalations. This is important during the mating season when the seals do not leave the beach to feed, and must conserve body moisture as they have no incoming source of water. These animals are colossally large in comparison with other pinnipeds, with southern elephant seal bulls typically reaching a length of and a weight of , and are much larger than the cows, with some exceptionally large males reaching up to in length and tipping the scales at ; cows typically measure about and . Northern elephant seal bulls reach a length of and the heaviest weigh about 5400 lbs (2455 kg).
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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