The Nature of Things·In Depth
The charismatic walrus should be the poster child for climate change, says researcher
The massive tusked walrus is surprisingly social and intelligent, but it faces a very uncertain future
They are large, tusked and impressive. One of the Arctic's most recognizable — and peculiar-looking — animals is also one of its most misunderstood. The walrus is among the largest of the pinnipeds, a group that includes seals and sea lions, weighing up to 1,700 kilograms. Once threatened with extinction due to overhunting, now the bigger threat is a warming environment.
In The Last Walrus, a documentary from The Nature of Things, we hear from experts who study the Arctic mammals in captivity and have discovered how little we know about them in the wild.
Walrus social life could be putting them in danger
Walruses know how to make friends. They might be massive, but they are social, intelligent animals. In the water, they often swim side by side, and when resting on land, they gather in large haulouts, sometimes numbering in the tens of thousands.
Like us, they live in social groups and family units, said John Miller, co-author of the book Walrus. "Walruses will suckle for between 15 to 19 months, but they stay with their mothers for two years, sometimes up to five years," he said. "[And] there are all these very finely marked out distinct subgroups: females that are pregnant, females that are nursing their young, females that are neither nursing or pregnant."
Males and females normally haul out in separate herds, and often it's a case of follow-the-leader. But this is leading to a concerning trend: mass gatherings on land. Over the last decade or so, scientists have recorded nearly 100,000 Pacific walruses hauling out along a 20-kilometre stretch of coast in northeast Russia — nearly the entire Chukchi Sea population.
Scientists' recordings of increasingly large walrus gatherings is correlated to summer sea ice loss — habitat offshore where the animals would normally be congregating in smaller groups. On-land gatherings have been increasing in size, often numbering in the tens of thousands.
These numbers raise the risk of disease for younger walruses, and large herds that are suddenly spooked can trample smaller animals as they stampede to the water to escape.
Beauty is in the 'ear' of the beholder
Walruses have a surprisingly large repertoire of sounds. Males use their vocal range to attract females during the mating season. They swim in patterns and sing, a courting ritual that is unique among pinnipeds. A walrus's song can last for days and be heard up to 16 km away!
Using their lips, nose, tongue and teeth, they generate all sorts of grunts, snorts, whistles, barks and whinnies. The complexity of their song has been compared to that of humpback whales.
The bell-like "ting" is an otherworldly call walruses produce using an inflatable pocket of skin in their throat.
Tusks are an adaptation to life in the Arctic
Their most defining feature, walrus tusks make an otherwise comical animal seem almost fearsome.
The tusks are canine teeth that grow up to one metre long throughout their lives. Although they appear cumbersome, the tusks are Swiss Army teeth that are used like an ice axe when hauling out onto ice floes or like crutches, for "tooth-walking," when moving around on ice.
They are also used to keep breathing holes in the ice open, and bulls will aggressively use their sharp teeth to battle rivals for territory or fend off interlopers interested in their harem of females.
Walruses need touch
Not only do walruses enjoy each other's company but they enjoy snuggling up too. "It also appears to be the case that walruses like touch," said Miller. "They need touch."
Even though they have an inch-thick hide, walruses are very tactile; so much of their world comes down to touch. "There's a lot of evidence that they thrive on physical contact," Miller said. "You can see them with their noses together, and we call this the 'walrus kiss.' And it's particularly important in the relationship between the mother and the calf walrus."
Walruses also communicate with their whiskers. "Their vibrissae or whiskers are incredibly sensitive organs that they use to communicate and to feel with one another," said Miller. These whiskers are also used to find shellfish hidden in the mud of the Arctic sea floor. Walruses are efficient at feeding and can consume up to 6,000 clams in a single feeding!
Their biggest threat is climate change
Two walrus subspecies call the Arctic home. The Pacific walrus can be found along the coasts of eastern Russia and Alaska and are estimated to be 200,000 strong, while the Atlantic population calls Canada's eastern Arctic, Greenland, Russia and Norway home, numbering at just 25,000.
They have been a crucial resource for the Inuit in the Arctic, and European hunters once harvested them for oil, ivory and their skin — used for machine belting, a widely used component during the Industrial Revolution.
Overhunting nearly drove them to extinction and populations disappeared in the St. Lawrence, and around Newfoundland and Sable Island, N.S. But the walrus's biggest threat now is a rapidly warming Arctic. According to David Rosen, a marine mammal researcher at the Vancouver Aquarium, "It is walruses, not polar bears, that should be the poster child for climate change and sea ice loss in the Arctic." Walruses are more reliant on ice than polar bears: they require ice floes to raise calves and forage for food efficiently.
In an ice-free world, they will have to swim farther to get food and haul out on land to rest. With ocean acidification, molluscs, their main food source, may become more scarce.
As the Arctic opens up, vast swathes of habitat will be lost to oil and gas exploration and mining, and industrial and shipping noise may exacerbate their stress, causing more stampeding among these easily spooked mammals.
Watch The Last Walrus on The Nature of Things.
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