Walrus
2007 Schools Wikipedia Selection. Related subjects: Mammals
| iWalrus | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 The Pacific Walrus
|
||||||||||||||||||
|
|
||||||||||||||||||
 Least concern (LR/lc) |
||||||||||||||||||
| Scientific classification | ||||||||||||||||||
|
||||||||||||||||||
|
|
||||||||||||||||||
| Odobenus rosmarus (Linnaeus, 1758) |
||||||||||||||||||
|
|
||||||||||||||||||
|
O. rosmarus rosmarus |
Walruses (from Dutch: wal meaning "shore", and r(e)us meaning "giant") are large semi-aquatic mammals that live in the cold Arctic seas of the Northern Hemisphere. Two subspecies exist: the Atlantic, Odobenus rosmarus rosmarus, and the Pacific, Odobenus rosmarus divergens. The Pacific walrus is slightly larger, with males weighing up to 1,800 kg (4,000 lb), but Atlantic males top out at 1,600 kg (3,500 lb). The walrus should not be confused with the elephant seal, another large pinniped.
Walruses are members of the order Carnivora and suborder (or alternatively superfamily) Pinnipedia. They are the only members in the family Odobenidae. The compound Odobenus comes from odous (Greek for "tooth") and baino ( Greek for "walk"), based on observations of walruses using their tusks to pull themselves out of the water. Divergens in Latin means "turning apart", referring to the tusks.
Life cycle
Walruses spend about half their time in the water and half their time on beaches or ice floes, where they gather in large herds. They may spend several days at a time either on land or in the sea. Diving to depths of 90 m (300 ft), they sometimes stay under for as long as a half hour. In the sea they sometimes catch fish, but generally graze along the sea bottom for clams which they suck from the shell. Abrasion patterns of the tusks show that the tusks are dragged through the sediment but are not used to dig up prey. Walruses can also spit jets of water to look for clams. Clams and mollusks form a large part of their diet. Large male walruses have been observed to attack seals if they cannot find any other food source.
Walruses mate in the water and give birth on land or ice floes. Breeding season is in mid-winter. The males show off in the water for the females who view them from pack ice. Males compete with each other aggressively for this display-space; the winners in these fights breed with large numbers of females. Older male walruses frequently bear large scars from these bloody but rarely fatal battles. After fertilization the egg remains dormant for several months, then a gestation period of 11 months follows. When a calf is born, it is over 1 m (3 ft) long and able to swim. Birth takes place on the pack ice; the calf nurses for about 2 years and spends 3 to 5 years with its mother. Females mature at about 6 years, males at 9 or 10. A walrus lives about 50 years.
Walruses have only three natural enemies: humans, orca, and the polar bear. Polar bears hunt walruses by rushing at them, trying to get the herd to flee, then picking off calves or other stragglers. Walruses have been known to kill polar bears. The walruses use their long tusks (elongated canines) for fighting and for display.
Population
Pacific
About 200,000 Pacific walruses exist. Pacific walruses spend the summer north of the Bering Strait in the Chukchi Sea along the north shore of eastern Siberia, around Wrangel Island, in the Beaufort Sea along the north shore of Alaska, and in the waters between those locations.
Smaller numbers of males summer in the Gulf of Anadyr on the south shore of the Chukchi Peninsula of Siberia and in Bristol Bay off the south shore of southern Alaska west of the Alaska Peninsula.
In the spring and fall they congregate in the Bering Strait, adjacent to the west shores of Alaska, and in the Gulf of Anadyr. They winter to the south in the Bering Sea along the eastern shore of Siberia south to the northern part of the Kamchatka Peninsula, and along the southern shore of Alaska.
Alaska Natives slaughter about 3,000 walruses annually. Humans use ivory from the tusks for carving. The natives call the penis bone of male an oosik and use it in making knives. Federal laws in both the USA and in Canada protect walruses and set quotas on the yearly harvest. Only under rare circumstances may non-native hunters gain permission to kill a walrus legally. The law prohibits the export of raw tusks from Alaska, but walrus-ivory products may come on the market if first sculpted into scrimshaw by a native craftsman. Commercial auction sites such as eBay make a large selection of "pre-ban" walrus ivory available.
Atlantic
About 15,000 Atlantic walruses exist: they live in the Canadian Arctic, in the waters of Greenland, of Svalbard and of the western portion of the Russian Arctic. The Atlantic walrus once enjoyed a range that extended south to Cape Cod and occurred in large numbers in the Gulf of St. Lawrence.
The walrus in popular culture
In Western culture, fiction often depicts the species—with its plump body, bushy mustache, and peacefully sleepy expression—as a happy, lovable and friendly animal, and its appearance may be interpreted as somewhat comical.
In literature and music
- Farley Mowat's book Sea of Slaughter has a large section dedicated to the effects of hunting on eastern Canada's walrus population.
- Lewis Carroll's famous poem " The Walrus and the Carpenter" inspired the 1967 song " I Am the Walrus" by The Beatles. In the song John Lennon is "the Walrus". However, in order to deliberately confuse his fans, Lennon sings in the later song " Glass Onion" that "the Walrus was Paul". In the solo song "God," Lennon sings "I was the Walrus, but now, I'm John."
- The Walrus is a Canadian news magazine.
- In Salman Rushdie's children's book Haroun and the Sea of Stories, The Walrus is the name of the imposing Grand Controller of Gup.
- Walrus is also the name of Captain Flint's ship in Robert Louis Stevenson's Treasure Island.
- Sam Allardyce, the manager of English football team Bolton Wanderers is often nicknamed Walrus, due to his uncanny physical resemblance to the creature.
Trivia
- Savoonga, Alaska calls itself the "Walrus Capital of the World".
- Walruses are among the only mammals in the world that do not process liquid waste via a bladder organ. Once digested, liquid waste is absorbed through the lining of the small intestine and secreted through the skin.
- A male walrus's penis is completely internal, however it has one of the largest bacula (penis bones) of the animal kingdom.