Walrus & Arctic Seals

Walrus & Seals

Members of the Pinniped family are well suited to life in the Arctic. The Pinnipeds include the Walrus, eared seals like sea lions and fur seals and the true seals. The word means fin footed. The Pinnipeds have sleek barrel shaped bodies with small fin shaped limbs and a good layer of blubber to insulate them in their mainly aquatic lifestyle. They are carnivores but specialized in their feeding preferences with many of the true seals feeding on fish and Walrus feeding on shellfish and other invertebrates from the sea bed.

Fossil Record

The remains of the now extinct Puijila darwini, one of the Pinnipeds earliest ancestors, was discovered on Devon Island in the Canadian Arctic in 2007. Roaming the arctic around 21 to 24 million years ago, it was about a metre long (3 ft) and was more like an otter than a modern seal, but it had flipper feet.

Walrus

Walrus
The Walrus is a large marine mammal with flippers, wiry whiskers and long ivory tusks. A Pacific adult male can weigh as much as 4,500lb, (2,000 kilo) but they are usually smaller, the only marine mammals larger than the walrus are the two species of Elephant Seals. There are 3 separate subspecies of Walrus, the Pacific Walrus, with a population around 200,000. The North Atlantic Walrus with a probable population of around 20,000 and the Laptev Sea population with between 5-10,000 animals.

Although walrus can stay submerged for up to 30 minutes they favour shallow waters where they can search in the mud for mollusks and other invertebrates, the method they use is extraordinary. Supporting themselves in the water on one flipper, they sift through the mud on the sea bed with their strong whiskers, at the same time fanning away the silt with the other flipper, when they find a clam they hold it in their lips and suck the meat out of the shell, using their tongue and arched palate to create suction.

A Walrus can live for up to 50 years. Before commercial exploitation in the 18 th & 19 th centuries, there were populations of Walrus as far south as Cape Cod and in the Gulf of St Lawrence.

Walrus hunting is now permitted only by the various indigenous populations in the areas where Walrus are found. In Greenland they are hunted early in spring on the new sea ice. In the Russian Far East they are hunted from open boats in the summer. The Chukchi artists of Uelen on the North Chukotka coast have a tradition of art engraved upon prepared walrus tusks while in Alaska they use the skins of walrus for the blankets in blanket toss and the skins of the traditional umiaks from which they hunt the bowhead whales.

Harp Seals

Harp Seal Pup
The Harp Seal is the most abundant of the northern hemisphere Pinnipeds. Named for the black ‘harp’ on the back of an adult seal, the Harp seal has the classic whitecoat pup that has been the centre of all the anti sealing activities in the past four decades, these pups are cute. The mothers milk is 48% fat and the youngsters gain 2kg every day, She will feed her offspring for around 12 days, then she just leaves. The pup will stay on the ice until it has moulted, then it needs to learn to fish for itself. It is believed that 30% of pups don’t survive their first year.

Harp seals spend their summers in the pack ice and travel in large rowdy groups, when they are travelling they porpoise through the water and mostly one just views their wet rounded backs, when curious, they bob up and down so their heads keep appearing and disappearing in the water, lots of heads! Some harp seals have been found to cover up to 4,000 km in a year. The seals overwinter at the edge of the pack ice and in spring haul out on the ice to breed. The density during this time has been reported as 2,000 seals per sq km of sea ice.

Hooded Seals

Hooded Seals are Arctic seals found in the ice around the edge of Greenland and up to Svalbard and down to the Gulf of St Lawrence. They are named for the bulge on the head of the male which he can inflate at will. The seal is uncommon, but not endangered and is noted for having the shortest lactation time of any mammal, the pups are born about Im long (3ft 3 ins) and weighing around 24 kg (56 lbs) The mother feeds her offspring for only 4 days and the pup doubles in size before leaving the safety of the ice. It is believed that the female’s milk is 60% fat. They feed on deep water sea fish.

Ringed Seals

Ringed Seals can be found all round the Arctic Ocean. They are small, compact, earless seals with short rounded faces, and are the only arctic seal that maintains a breathing hole in the winter sea ice, enabling them to overwinter deep in the arctic. The female gives birth to a single pup in a birthing den that is over the hole into the seawater, but usually under a mound of snow or an overhang of ice. Unlike the speed nursing of the Harp & Hooded seals, a ringed seal will suckle its pup for about 40 days. It has been reported that Climate change is breaking up these birthing dens before the young seal is full ready to fend for itself, leading to poor condition in the growing seal. Ringed seals live mainly on fish they catch and are, themselves, a primary food source for Polar Bears. They take their name from the dark rings on the back of the adult pelt. Ringed seals have always been hunted by the indigenous peoples of the Arctic who use their soft skins for clothing and the meat is eaten raw or boiled.

Bearded Seals

Bearded Seal
Bearded Seals are a medium sized earless seal and the male and female are around the same size, the female feeds her single pup for 18 to 24 days and the baby swims from very early on, quickly becoming proficient. Bearded seals are solitary and prefer to rest on ice floes and feed in shallow water on the fish and invertebrates that they sift out with their long whiskers, from which they take their name. When they have been resting on the ice for a while the whiskers dry out and curl at the ends, looking very curious. Bearded seal are an important prey animals for polar bears and the Inuit populations of the Arctic use the skins for all the heavy duty jobs, boot soles, dog whips, hide rope and boat skins.

It is fascinating to compare the true seals of the Arctic and Antarctica. In the Arctic the seal’s land based predators have shaped their behaviour, the pups are born with a camouflaging white coat, the ringed seal maintains lots of breathing holes so that if a Polar Bear is at one, it has others to use. In Antarctica the pups are born grey, the weddell seals will share one breathing hole during the winter because nothing will ever threaten that single lifeline to the air. Antarctic seals can sleep soundly when they haul out of the water onto the ice, in the Arctic they need to always be aware of the presence of polar bears.

Links

The Walking Seal

Seaworld Walrus Info Book

Animal Diversity Harp Seals

Animal Diversity Hooded Seals

Animal Diversity Ringed Seals

Animal Diversity Bearded Seal

 


Text © B & C Alexander