Walruses can weigh up to 1,600 kilograms (3,527 pounds) and grow up to 3.7 metres in length. Their tusks can measure a whopping one metre and they can live for up to 50 years in the wild.
The walrus is magnificently adapted to life in the sea and on ice. Its scientific name (Odobenus rosmarus) derives from a combination of Greek and Scandinavian words meaning "tooth walking sea dog". They dont actually walk on their teeth but often haul themselves up onto the ice using their enormous tusks. Although related to the seal and sea lion, the walrus is a single species divided into two kinds: the Atlantic and Pacific walrus.
During the Artic winter the walrus heads south but has no difficulty keeping warm due to its thick, deeply wrinkled skin and up to seven centimetres of underlying blubber.
Walrus need to consume huge quantities of food before searching for land in the Arctic summer. The staple diet is clams and other molluscs (thousands each day); the walrus dives to the ocean floor and scans for food with its whiskers.
The walrus mates in the water between January and March with the average gestation being 15 months. A single pup (measuring about 125 centimetres) is born on the ice and is dependant on its mothers milk for at least 18 months before it can become adept at swimming and leave to join other youngsters at about two-years-old.
The walrus on land is an awkward, lumbering creature but, once at sea, is graceful and powerful. A cone shaped body and huge rear flippers (up to a metre across) mean the walrus can easily reach speeds of 10 kilometres (six miles) per hour and dive to depths of 300 metres.
Jim McNeill, Founder and Leader of the Ice Warrior Project, had a close encounter with a Walrus.
My most memorable encounter with walrus came when I inadvertently surprised a whole floating ice island full of the creatures doing what they do best sleeping!
My boat came round the back of an iceberg and went within ten metres of this pan of ice. The walrus really went mad, all splashing in the water together, causing a mini-tidal wave for the boat I was in. Everyone on board got a fright!
Polar bears rarely take on an adult walrus whose tusks can inflict fatal wounds. They will, however, charge into a walrus herd and take a pup. The walrus also occasionally falls victim to a hungry killer whale.
Historically, hunting and commercial ships have posed the biggest threat and the walrus remains very wary of man. The Marine Mammal Protection Act of 1972 has seen the population of Atlantic walrus grow to between ten and fifty thousand, but the Eskimos are still legally allowed to hunt walrus within limits. Global warming and the erosion of sea ice will reduce the creatures calving grounds.
The Inuits traditional way of life depends substantially on their ability to hunt walrus. As well as providing food for themselves and their dogs, walrus skin and bones are used for clothing, tools, weapons and hide boats, while the oil is used for lighting and heating. The tusks are carved into ivory ornaments (called scrimshaw).
- Walrus stomach, buried in snow until the winter months, is an Inuit delicacy.
- The Eskimo mother traditionally used a chunk of walrus blubber on a stick as a dummy for her baby.
- The walrus has sacs in its throat which it can fill up with air, enabling him to sleep at sea.
- Bull walruses use the length of their tusks as a ranking system the longer the tusks, the higher up in the herd and the more likely to attract a mate.
- You can establish the age of a walrus by looking at a cross section of its tusks (they have rings).
- The longest tusk recorded was 94 centimetres and weighed over five kilograms (11 pounds).
- The penis of the bull walrus is hidden away inside his body.