In Search of the Tooth Walker
In the frigid Arctic, researchers attempt to assemble the puzzle that is the Atlantic walrus
- Michael Vlessides - Photographs by Paul Nicklen
- Nov 01, 2000
It was surprisingly easy to overlook Rob Stewart and Clement Lanthier as they crawled along the gravel beach of a lonely Arctic fjord in their dun-colored overalls. Then again, when one is keeping extraordinarily close company with several dozen Atlantic walruses, some of which can weigh as much as 3,500 pounds, anonymity is often a desirable characteristic.
With his target squarely in sight, Stewart whispered instructions to Lanthier via radio headset, slowly raising the rifle he´d been shouldering for the past several hours. A shot ripped through the air. Twenty yards away, a massive bull walrus jerked as a dart loaded with enough immobilizing drugs to knock out a family of gorillas penetrated his one-and-a-half-inch hide.
It was a successful day for Stewart, a research scientist with Canada´s Department of Fisheries and Oceans (DFO) in Winnipeg, and Lanthier, a veterinarian specializing in wildlife. It was also the only victory they´d muster during this particular two-week trip to the remote haunts of Ellesmere Island, as an unexpectedly high number of females and calves kept the researchers separated from the adult bulls they sought to study. Such is the nature of investigating the Atlantic walrus of the eastern Canadian Arctic, where decades of work by Stewart and his colleagues are only beginning to shed some light on the complex character of these enigmatic animals.
Throughout history, few creatures have so staunchly wrenched themselves into popular imagination as has the walrus. For millennia, Inuit peoples regarded them as alternatively possessing supernatural and human attributes. Nineteenth-century British sailors considered them "unearthly and demoniacal." Two centuries later, they are often erroneously deemed to be no more than bucktoothed, overweight bullies, a stereotype that neglects the true nature of a mammal marvelously adapted to one of the world´s harshest environments.
Walruses are pinnipeds, a widely distributed group of marine mammals that also includes sea lions and seals. Scientists generally recognize two distinct subspecies: the Atlantic walrus (Odobenus rosmarus rosmarus) and the Pacific walrus (Odobenus rosmarus divergens). (Some scientists consider the walrus of the Laptev Sea, off the coast of Siberia, to be a third subspecies.) The word Odobenus is derived from the Greek "tooth walker," born of the walruses´ propensity for hauling themselves up onto the ice with their signature tusks, which can grow to be 3 feet long in adult males and weigh as much as 12 pounds each.
Pacific walruses are more migratory and more numerous than their Atlantic counterparts. They are most commonly found in the Bering and Chukchi seas of Alaska and Russia, and are thought to exceed 200,000 in number. Pacific walruses are also much better understood than the Atlantic variety, the result of much greater research funding by the American government. Stewart´s efforts, however, are helping to close the knowledge gap between the species.
"Until a few years ago, work on Atlantic walrus had fallen way behind in terms of priorities," notes Becky Sjare, a marine mammal scientist with DFO in St. John´s, Newfoundland. "And from the behavioral perspective, virtually nothing had been done. So Rob has made major contributions to the field in that regard."
No amount of research has helped the once-abundant Atlantic walrus to rebound from the human exploitation that ravaged its ranks over the past three to five centuries, however. As a result, the population has been reduced to a mere fraction of the several hundred thousand animals it once boasted. Increased human activity has been the primary culprit preventing the Atlantic walrus from repopulating much of its traditional range, although commercial hunting, poaching and aboriginal hunting have played a role as well.
Today, Atlantic walruses can be found along the coasts of Greenland and scattered throughout the remote islands north of Norway and off the northern coast of eastern Russia. The majority of the world´s population of Atlantic walruses inhabit Canadian waters, however, and are found in sections of Hudson Bay, Foxe Basin, Baffin Bay, Davis Strait and around the High Arctic islands. Currently there are no reliable data on the world population of Atlantic walruses (estimates range anywhere from 10,000 to 50,000), indicating the formidable challenges of studying these animals.
Stewart knows well these challenges. Since 1988 he has performed a variety of studies on the walruses of the eastern Canadian Arctic, examining haul-out behavior, growth, reproduction, diet, digestive efficiency and disease prevalence, among other topics. On his latest field trip to Ellesmere Island, however, the primary goal was to immobilize walruses and place radio transmitters on their tusks, which will help shed light on their dive depths, dispersal and migration patterns, and critical habitats.
"It´s turning out not to be the easiest thing in the world to do," Stewart says. "You can go almost anywhere in the North and locate ringed seals to study. If you want to work on harp seals, you know where to find virtually all of them during breeding season. That´s not the case with walruses. They have a sort of clump distribution over quite a large and remote area that makes them especially difficult to research."
Stewart relies on the knowledge of Inuit hunters in the region to help pinpoint areas where walruses traditionally emerge from the sea, or haul out, to rest between feeding trips. These haul-out sites (known as uglit among Inuit) can boast hundreds, and sometimes thousands, of walruses, jammed together in paradoxical harmony. For while walruses will allow their neighbors to literally lie on top of them, they will frequently rise up to trade tusk jabs as well.
Since Stewart would rather not immobilize female walruses because of the effects the drugs may have on pregnant or lactating females and their calves, the next challenge is to locate a suitable adult male. This would not be a problem among Pacific walruses, as males typically haul out together in bachelor groups that can boast several thousand members. Stewart has not been as fortunate in the Canadian Arctic, however, as he has only encountered mixed haul-out sites, at which females usually far outnumber and often surround the males.
For Stewart and Lanthier, who is the curator and veterinarian at the Granby Zoo in Granby, Québec, the result is an inordinate amount of time spent on all fours, shuffling along the beach in search of an adult bull. And as one might imagine, an area that walruses use to rest between feedings is riddled with a substantial amount of walrus excretions. "Let´s just say we´ve developed some skill in terms of wading through all kinds of stuff on the beach to get fairly close to the walruses," Stewart says.
"It´s part of the process," relates Lanthier, adding that the smell of a haul-out site is difficult, if not impossible, to forget: "We call it ´Chanel Arctic.´"
Once a positive identification is made, the researchers need to convince the surrounding females, which stretch about 8 feet long and weigh an average of 1,200 pounds each, to move aside to create an avenue to the male. This is usually accomplished by creeping slowly toward the group, an action that makes the nearest walruses uncomfortable enough to edge away. The trick in these instances, Stewart says, is to avoid getting between the animals and the water, because if something goes wrong and the animals startle, they invariably move seaward with alarming speed.
In addition to the potential danger posed by a herd of stampeding walruses, there are other hazards. Stewart tells the story of a group of researchers that once moved toward a small group of walruses in search of a male, only to return when they realized their trip was in vain. "They turned around just in time to see a polar bear make a rush at the same group of walruses from the opposite side," Stewart says. "And because we wear brown overalls, we look just like little walrus calves on the beach. And a hungry polar bear would like nothing better than to get at an isolated walrus calf."
While polar bears will occasionally kill a calf, they do not pose a serious threat to an adult, whose formidable tusks, great girth and thick hide combine to make a fearsome enemy. Agitated walruses have been known to turn aggressively on both human and nonhuman interlopers. Mother walruses are also fiercely protective of their young and will go to extreme lengths to keep them out of harm´s way. Alaskan biologist John Burns once watched a female walrus systematically destroy a heavy piece of ice with her tusks to free her calf, which had fallen into a crevasse.
Scientists speculate that the mother´s commitment to the calf is the result of a reproductive cycle that sees females give birth once every two or three years, at the most. "Unlike most seals, which can pump out a pup every year, female walruses only get a few chances at having calves," says Ted Miller, a biology professor at Memorial University in St. John´s, Newfoundland. "So every calf is very precious."
Indeed, no other pinniped species suckles its young as long as does the walrus - three years in some instances. During that time, mother and calf are virtually inseparable. The cow will shelter her calf from the wind when on the ice, give it piggyback rides through the water should it grow weary, and, in rare cases, clutch the calf to her breast with her foreflippers in the face of perceived danger.
If there is one way in which the enigmatic walrus meets society´s expectations, it is in its unbridled appetite. Walruses will eat as many as 6,000 individual organisms (as much as 120 pounds of food) in a single feeding foray. Walruses are bottom feeders and generally graze on slow-moving prey in waters no more than 250 feet deep; several species of clams comprise the majority of their diet. "In many cases, however, clam densities and distributions aren´t such that walrus can only eat clams," notes Sjare. "So they´ll eat just about any type of bottom-dwelling organism, including snails, sea cucumbers and the occasional rock." An adult male walrus may also kill and eat ringed and bearded seals.
Contrary to popular belief, walruses do not use their tusks either to locate prey or dredge it up. Rather, they find food via the sensitive touch of their 600 to 700 vibrissae, or whiskers, which have been likened to multifingered hands on the animals´ snouts. Once they locate prey such as clams (which can be buried as deep as six inches), walruses extract them by a form of sandblasting. "They suck in water and then jet it out under extreme pressure like a hose," Sjare relates. "They then suck up the siphon and part of the foot of the clam. In some cases, the suction is so great that the clams are totally crushed." According to Miller, walruses in captivity have been known to suck a hole through plywood.
Walruses spend the majority of their lives in the water, but they are highly dependent on ice. As with land-based haul outs, walruses will use ice floes as places to rest during feeding sessions, as well as to molt and bear their young. Some scientists speculate that global warming is decreasing the amount of ice available to walruses for these activities. Others say that as warming causes coastal ice to retreat, walruses may have to swim exhausting distances to reach the waters in which they feed. The result could be potentially dire consequences for both Pacific and Atlantic walrus populations.
Stewart, however, is not a proponent of this theory. "There was a very healthy walrus population in the Gulf of St. Lawrence until about 150 years ago, when they were hunted out," he says. "That gulf has a large ice-free season, and did so when the walruses were there. So Atlantic walruses have historically existed quite happily in areas that have only seasonal ice."
Like so many aspects of the walrus, however, the effects of a worldwide increase in temperature on its life-style is at present not much more than speculation. With time, however, work by scientists such as Stewart will help build a clearer picture of a creature whose natural history remains largely shrouded in mystery.
Stewart´s Ellesmere Island radio-transmitter research, while still in its early stages, already seems destined to change the way researchers think about walruses´ diving habits. "It was long believed that walruses were 80- or 100-meter divers," he notes. "But we´ve got one going down as far as 178 meters."
And if there are any drawbacks to crawling across windswept beaches in the Arctic, Stewart says they´re far outdistanced by the rewards of the work. "I think we´re trying to ask reasonable questions," he says. "It´s just that they´re difficult questions to ask, which may be why people didn´t ask them in the past."
Michael Vlessides resides in Canmore, Alberta. This is his first story for International Wildlife.
Photographer Paul Nicklen was trained as a marine biologist and began photographing professionally in 1994. He now lives in Whitehorse, Yukon.