![]() ![]() Apart from the tusks, walruses generally have few teeth. They will also poke the tusks through an air hole and rest on them while keeping the nostrils above the level of the ice and water. The walrus uses its tusks to make and maintain air holes. The male with the largest tusks will usually be the dominant animal is a social group and will use his tusks to defend his harem. Males use their tusks, which are slightly longer and thicker than the females’, for dominance and display. Both males and females have tusks which may grow to a metre in length and weigh up to 5.4 kg. The most prominent feature is the tusks which are really elongated canines. It also shares with true seals an absence of external ears. Like the true seals, it tends to rely on whole body movements to move through the water rather than using the flippers to swim with. The walrus can turn its rear flippers forward and move on all fours. Females weigh about 2/3 rds as much as males. The Atlantic also has somewhat shorter tusks and a more flattened snout. Most Pacific males weigh between 800 and 1,680 kg with Atlantic males weighing 10 to 20 % less. The walrus spends most of its time in the shallow oceanic shelf habitat, foraging for its preferred food of benthic bivalve molluscs. The Laptev population is calculated at between 5,000 and 10,000 animals, confined to central and west areas of the Laptev Sea, eastern parts of the Kara Sea and western parts of the East Siberian Sea. There are much smaller numbers of Atlantic walruses which inhabit coastal regions from north-eastern Canada to Greenland. Smaller numbers are found on the south shores of the Chukchi Peninsula and southern Alaska. The bulk of the Pacific walruses spend their summer north of the Bering Strait off the northern shores of Russia and Alaska. The Atlantic walrus (O.rosmarus rosmarus) is found in the Atlantic Ocean, the Pacific walrus (O.r.divergens) in the Pacific Ocean and O.rosmarus laptevi in the Laptev Sea. The walrus cannot be mistaken for anything else, what with its great bulk, prominent tusks and bewhiskered snout. Only the two elephant seal species out-weigh the walrus. Pinnipeds are fin-footed, semi-aquatic mammals such as the eared or true seals, the earless seals and the walrus. The walrus belongs to a diverse group of animals known as pinnipeds. By disturbing the sea floor, nutrients are released, organisms are amalgamated and the benthos are refreshed. The value of the walrus is that, by its foraging, it has a huge peripheral impact on benthic communities, meaning those collections of organisms on the sea bed. Other keystone species include the prairie dog, cassowary and mountain tapir. Keystone species are those organisms which have an influence on their environment which would seem out of all proportion to their size and/or number. The walrus is also considered a keystone species of Arctic marine ecosystems. The species name ‘ rosmarus‘ means ‘sea-horse’. This refers to the habit of the walrus of pulling itself out of the water with its tusks. The genus name came about as a combination of two Greek words – odous meaning ‘tooth’ and baino meaning ‘walk’. Some of these are the moose, pronghorn, okapi and numbat. There are a number of animals that are the sole representatives of their particular genera. ![]() The walrus is a monotypic species as it is the only living species in the genus Odobenus. ![]()
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