Walruses have lots of things similar to true seals andeared seals. Like true seals, they just have a hole for anear - not ear flaps. Like eared seals, they can rotate their back flippers forward towalk on land. Like both true seals and eared seals, they are very goodswimmers and divers. However, walruses do have somefeatures that neither true seals nor eared seals have.
The most famous thing about walruses are theirtusks. Even though they are called tusks, they are actually teeth growing out of their mouth, a bit like thenarwhal. The tusks grow for about 15 years before they reach their fulllength, which is about 102 cm (40 in) for males and 76 cm (30 in) for females.
Both the male and female walrus grow tusks. They can use them to protect themselves frompolar bears andkiller whales and use them when they eat. When they eat bigger preys such asseals and smallwhales, they first tear them apart with their tusks to make them easier to eat. Another important use of a walrus's tusks is to pull itself out onto the ice. Pushing its tusks into theice, the walrus gets extra help hauling its huge body out of thesea. This is probably how walruses got their family nameOdobenidae, which comes fromGreek words meaning "one that walks withteeth". They do not walk with their teeth, but it can look as if they do when they pull themselves out of the water. Their tusks can also be used to cut holes in theice.[3] Tusks are slightly longer and thicker among males, who use them for fighting, dominance and display; the strongest males with the largest tusks typically dominate social groups. Tusks are also used to form and maintain holes in the ice and aid the walrus in climbing out of water onto ice.[4]
Walruses are very big, even compared to big malesea lions. When they are all grown up, they can weigh more than 1,400 kg (3,086 lb). The walruses that live in theAtlantic Ocean are a little smaller than the ones in thePacific Ocean. Both kinds like to stay in the cold north. With all theirblubber, which can be as much as 6 in (15 cm) thick, they are very comfortable inicywater.
Walruses are usually brown, but walruses can change colourdepending on how warm they are. They are usually different kinds of brown, but as they get warmer, their skin can turnpink. This is because as they get warmer, blood rushes to the skin to try to cool it.
The walrus has an air sac under itsthroat which acts like a flotation bubble and allows it to bob vertically in the water while sleeping.
The males have a largepenis bone, up to 63 cm (25 in) in length, the largest of any land mammal, both in absolute size and relative to body size.[5]
↑Berta A. and Sumich J.L. (1999).Marine mammals: evolutionary biology. San Diego, CA: Academic Press. pp. 494 pp.
↑Fay F.H. (1982). "Ecology and biology of the Pacific walrus,Odobenus rosmarus divergens".United States Department of the Interior, Fish and Wildlife Service.
