Tuesday, May 29, 2012

Walrus (Odobenus rosmarus)

Both male and female walruses have tusks and have been observed using these overgrown teeth to help pull themselves out of the water.
The mustached and long-tusked walrus is most often found near the Arctic Circle, lying on the ice with hundreds of companions. These marine mammals are extremely sociable, prone to loudly bellowing and snorting at one another, but are aggressive during mating season. With wrinkled brown and pink hides, walruses are distinguished by their long white tusks, grizzly whiskers, flat flipper, and bodies full of blubber.
Walruses use their iconic long tusks for a variety of reasons, each of which makes their lives in the Arctic a bit easier. They use them to haul their enormous bodies out of frigid waters, thus their "tooth-walking" label,
and to break breathing holes into ice from below. Their tusks, which are found on both males and females, can extend to about three feet (one meter), and are, in fact, large canine teeth, which grow throughout their lives. Male walruses, or bulls, also employ their tusks aggressively to maintain territory and, during mating season, to protect their harems of females, or cows.
The walrus' other characteristic features are equally useful. As their favorite meals, particularly shellfish, are found near the dark ocean floor, walruses use their extremely sensitive whiskers, called mustacial vibrissae, as detection devices. Their blubbery bodies allow them to live comfortably in the Arctic region—walruses are capable of slowing their heartbeats in order to withstand the polar temperatures of the surrounding waters.
The two subspecies of walrus are divided geographically. Atlantic walruses inhabit coastal areas from northeastern Canada to Greenland, while Pacific walruses inhabit the northern seas off Russia and Alaska, migrating seasonally from their southern range in the Bering Sea—where they are found on the pack ice in winter—to the Chukchi Sea. Female Pacific walruses give birth to calves during the spring migration north.
Only Native Americans are currently allowed to hunt walruses, as the species' survival was threatened by past overhunting. Their tusks, oil, skin, and meat were so sought after in the 18th and 19th centuries that the walrus was hunted to extinction in the Gulf of St. Lawrence and around Sable Island, off the coast of Nova Scotia.

Fast Facts

Type:
Mammal
Diet:
Carnivore
Average life span in the wild:
Up to 40 years
Size:
7.25 to 11.5 ft (2.2 to 3.5 m)
Weight:
Up to 1.5 tons (1.4 metric tons)
Group name:
Herd
Protection status:
Endangered
Did you know?
The walrus' scientific name, Odobenus rosmarus, is Latin for "tooth-walking sea-horse."

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