The Walrus is an easily identified large marine mammal; it is easily identified by its large tusks and long whiskers. It is a large and heavy animal with a size among seals only exceeded by Elephant Seals. It is a carnivorous marine mammal with genetic evidence that it evolved from an early form of bear. Although larger sub species exist this article looks at the Atlantic species. Males of this species can weight nearly 4000lbs with females around 3000lbs, the larger Pacific species also tends to have longer tusks. Physically it has features seen in both sea lions and seals - like a sea lion it can turn its rear flippers and move on all fours but it swims much more like a seal and like seals it doesn’t have external ears.
Walrus are often identified by their long tusks which are actually canine teeth, both males and females have tusks although the males have longer tusks which have been known to reach over 3ft in length. The Tusks of the males are used for fighting and display but both sexes use the tusks for moving sediment (not digging as first thought). The tusks are also used to help pull the animal out onto ice flows. The Walrus also has distinctive whiskers or Vibrissae; these can number over 400 on some animals and are about 30cm in length. They are sensitive organs which allow the Walrus to identify food on the sea bed.
Walrus skin is virtually bald but very thick up to 10cm around the shoulders of a male animal with a 15cm layer of insulating blubber underneath. Young animals are a dark brown but the skin becomes lighter with age with old males appearing pink (see author's photos). In cold arctic waters the skin can appear as white as the blood vessels constrict to conserve heat. An air sac under the Walrus’s throat allows it to float and sleep vertically in the water safe from land predators.
Although slow and bulky on land and hence vulnerable to predators Walrus are powerful swimmers able to reach 22mph in the water and swim for days in the open sea sometimes covering over a 100 miles, they are also able to dive to depths of around 240ft. Walruses can live up to 30 years in the wild with most animals not mating until they reach 15 years (males) and 4 years (female). During the mating season at the start of the year they cut their food intake. The males sing to attract a mate with a complex series of bell like tones and clicks which carry over several kilometres. Mating takes place in the water where there are fewer predators. Pregnancy lasts up to 16 months due to delayed implantation so that the calves are born at the best time of year normally between April and June. A calf can weigh up to 170lbs and can swim from birth but can spend 2- 5 years with their mother who will not breed during this time making the birth rate very low for any member of the seal family.
The Walrus's main predator has like many animals been man. Many of the indigenous Arctic people hunt Walrus for meat, skin and tusks. In previous centuries the animal was commercially hunted for ivory and fat, this had a massive impact on populations but these have since recovered to some degree since commercial hunting was banned. Traditional people will preserve the meat for the long winters and walrus flippers are considered a delicacy by some groups. The oil could be burn for warmth and light with the bone and hide making tools and waterproof linings and boat parts. Because of this the Walrus features in the faiths and legends of many of the Arctic peoples, including the native Indian myth of the Raven, in some legends the Walrus is linked to the Northern lights with the lights believed to mark a special land where those who died by violence dwell playing ball with a walrus head.
The Walrus has few natural predators due to its size power and speed in the water; the only two animals to prey on them are both apex predators, the Orca (killer whale) and the Polar or White Bear. Walrus are not a common prey for either of those predators, Orcas will prey on young and sick in the water, while Polar bears will spook a group at rest on land and look for animals wounded as the walrus rush for the water, normally sick, old or young animals, even for such a powerful hunter as a Polar bear a fully grown and healthy walrus is a dangerous animal. Walrus numbers are potentially under threat due to global warming reducing the amount of pack ice in recent years. Without the thick pack ice the Walrus have few places to gather, breed and give birth as well as limiting resting places near feeding grounds. Walrus tend to feed in shallow coastal regions and don’t dive as deep for food as other members of the seal family but can remain underwater for up to 30 minutes. Walrus are not overly specialized and feed on over 60 different marine creatures from shrimps to crabs, tube worms, mollusks and sometimes other seals. A favoured food is clams which they graze from the sea bed using their whiskers, sucking the meat out of the shell by suction rather than cracking the shell. Occasionally Walrus have been known to eat seabirds.