Polar Bears

After two seasons working as a polar bear guide in Churchill, Manitoba, I thought I had more or less filled my cup as far as observing polar bears was concerned. I’d seen bears every working day during this time—sometimes as many as thirty in one day, up close and personal. I witnessed them lying about, sauntering around with that pigeon-toed walk, and sparring with one another. I’d seen mothers nursing cubs, big males, saucy teenagers—the full gamut. Enough bears for one lifetime to be sure, I thought.

These bears in Churchill were all merely waiting through summer on land to get back onto the winter’s sea ice, where their real active living took place—hunting for seals. When I saw my first bear out on the ice, I realized that my cup was most definitely not full. There was still a lifetime of bears worth seeing.

Polar bears are what everyone hopes to see on an Arctic trip. But seeing bears on small-ship expeditions through the North is unlike seeing them on land in Churchill, where their presence is reasonably predictable, they are accustomed to people in tundra buggies, and they are simply waiting until the sea ice forms again. It’s important to know what types of sightings you might get based on what type of trip you choose.

An Eye-Opening Sight

I was in Jones Sound, between Ellesmere and Devon Islands, on a High Arctic Adventure Canada expedition, when I saw my first bear doing what it was meant to do—the result of over a million years of evolution. It was August 24, 2007, about 10:30 p.m. The light was muted, but visibility was still good—after all, it was late summer well above the Arctic Circle.

The bridge officers first spotted the bear perhaps two kilometres away, so they slowed the ship to a crawl and manoeuvred quietly through the loose ice towards the distant speck. The bear seemed preoccupied, taking almost no notice of our hulking ship. As we got closer, we could see why it was so unconcerned about us: it had a freshly killed ringed seal. Rare ivory gulls, a marvellous sighting in themselves, flitted about waiting for the bear to have its fill. It made me wonder how, in such a vast, open space, animals could know that—right here, right now—this was the place to be.

A small, quiet throng of people had gathered on the uppermost deck. Margaret Atwood and the late Graeme Gibson were beside me. No one spoke. Graeme looked at me wide-eyed, grinning from ear to ear. We knew what a rare privilege it was to witness this slice of a bear’s life—this pure, wild moment. The bear looked up from time to time, its muzzle scarlet with blood. Time froze as we quietly floated there while the bear fed contentedly, and the pure white gulls flapped and waited. Red blood on white ice. This was bear spirit. This was the heart of Arctic wildness.

Bears on the sea ice are few, far between, and often distant. But they are in their element—skilled predators perfectly at home on the ice and in the water, even in the winter when the sun sets in October and doesn’t rise again until late February. The air temperature can plunge to minus fifty degrees Celsius and stay that low for weeks. A warm-blooded Arctic animal must maintain a temperature gradient of almost one hundred degrees between its body core and the outside air. So, how do they do it?

“The awe one feels in an encounter with a polar bear is, in part, simple admiration for the mechanisms of survival it routinely employs to go on living in an environment that would defeat us in a few days.” — Barry Lopez, author of “Arctic Dreams”

Cold-Hardy Specialists

Going from outside in, polar bears have two layers of fur: a layer of long guard hair and an inner layer of underfur. The guard hair sheds water and seals the underfur like a neoprene dry suit when the bear is immersed. Water does not reach the skin except in areas where the fur is thin or absent. Each guard hair is hollow with an insulating air chamber, which aids with both heat conservation and buoyancy. In contrast, the underfur is dense, soft, and air-filled like the very best home insulation. Beneath that is a thick layer of skin, followed by a much thicker layer of fat that varies throughout the year, but can be up to eleven centimetres thick. The fur maintains the body heat in air, while the fat layer works better in water.

Compared to other bears, polar bears have small ears and tails and a larger body, which gives them a surface area to body mass ratio that conserves heat. When they sleep in the cold, they will burrow into a snowbank and ball up, reducing their exposure and surface area even further.

However, they do have a long nose compared to other bears, which is densely packed with olfactory sensors to give them a highly tuned sense of smell. It also helps conserve heat. Inside the nasal area is a sophisticated heat exchange system that warms incoming air and cools outgoing, so cold air does not enter the lungs and reach the body core, while warm air and water vapour is not lost to the environment. They would have no trouble passing a home inspection heat-loss test.

But what about their feet? There is little insulation between their soles and the frigid snow and ice. Like many other cold climate mammals and birds, their bodies simply allow their feet to cool to near freezing, through another countercurrent heat exchange system in the legs. Bears also use vasoconstriction to reduce the flow of blood to peripheral parts of the body in preference for keeping the core warm.

It must be said that polar bears are not unique in their cold coping capabilities. Many other Arctic animals have similar adaptions, but, in nanuq (Inuktitut for polar bear), these adaptations reach their pinnacle of perfection.

A High-Fat Diet

Staying warm requires fuel, and that comes from seal fat. While black and brown bears munch on berries, polar bears go straight for the high-octane stuff. An adult bear needs two kilograms of fat per day—18,000 calories, or the equivalent of seventy Big Mac burgers. An adult ringed seal, weighing in at about seventy kilograms of fat and protein, will provide a bear with sufficient food to maintain its weight for about eleven days. However, bears always face a lean fasting period during the summer on land, so they need to pack on the pounds whenever the hunting is good.

Bears are more efficient at processing fat (97% conversion) than protein (84% conversion), so if hunting is good, bears will feast on the blubber but then leave the rest of the seal carcasses behind, much to the delight of ravens, ivory gulls, and Arctic foxes. A bear can eat 10% of its bodyweight in a half hour, and its stomach can hold 20% of its bodyweight. Polar bears are fat-processing machines with no cholesterol problems.

I once heard a story of a female bear with cubs that was caught in a trap near Churchill as part of a scientific study. She was so gaunt that the biologists thought she would not survive. Nine months later, after her cubs were weaned, she was trapped again and had gained over four hundred kilograms (nine hundred pounds)! She was no slouch when it came to hunting seals.

The Nose Knows

A polar bear’s visual acuity is about the same as ours, but their night vision is better. The real key to a polar bear’s hunting success is its nose. It has the largest olfactory area of any land mammal. An ecology professor who studied polar bears told me once of following bear tracks over the snow-covered ice by helicopter, to a point where the bear suddenly made a ninety degree turn and proceeded another sixteen kilometres in a straight line to the ice edge and a seal carcass. Now that’s a keen nose!

A bear uses its nose to find seals beneath the ice, especially in spring when ringed seals create lairs within the ice pack to deliver and raise their pups. A bear can smell the seal through the thick snow, break through the roof of the den with its powerful forepaws, and snatch the pup—a polar bear version of fast-food take-out. Similarly, it can smell a ringed seal’s breathing hole in the ice and will wait silently until the seal rises headfirst to take a breath, only to be killed instantly by the bear’s strike. On average the bear succeeds at this about once in every five attempts.

A Sleek Hunter

Polar bears are highly accomplished stalkers. A bear might see or smell a seal resting on an ice floe from some distance away. It uses whatever cover it can to stay hidden as it creeps closer to its potential prey. If it needs to enter the water, it takes note of the seal’s position and slithers in silently. Submerged, or using floating ice pans as cover, it quietly paddles closer, raising its head from time to time to recheck the seal’s location. When the bear is close enough to the seal, it explodes out of the water and onto the ice in one movement to grab the seal before it escapes. In the water, the bear does not have much of a chance to catch a seal, because its prey is faster and more agile.

At Coningham Bay, off Shartoo (Prince of Wales Island), Nunavut, there is a shallow lagoon where belugas congregate from time to time. The only entry is through a narrow inlet. Polar bears don’t hunt many belugas, but they are intelligent opportunists, so this is an exception. The dozens of whale skeletons all around the lagoon’s perimeter are evidence. It was here that I watched as a bear entered the water from land and convincingly imitated floating ice pans. It lay still in the water with just the top of its head and back showing. Its neck was submerged so that it looked like two small pans. Only the black eyes and nose that rose from time to time reminded me that it was a bear. Had I not seen the bear enter the water, I would not have known the difference.

As marine mammals, polar bears are such competent swimmers that they have been found hundreds of kilometres out to sea. A bear in the Beaufort Sea set the record for a long-distance swim of 687 kilometres in nine days. This is indeed exceptional, but bears will routinely cross open bays and wide leads, probably for the same reasons that chickens cross the road. Each spring we get reports of polar bears on the northeast coast of Newfoundland having arrived on the drifting pack ice. This is the southern extent of their world-wide distribution. When the ice melts, they no doubt go north again, swimming and following the land.

A Changing World

So how are polar bears doing in these changing times? Truth is, we don’t have good data from the entire Arctic to know for sure. Scientists divide the total polar bear population into nineteen subpopulations, some of which we know far more about than others. As of 2019, four of the subpopulations were declining, five were stable, two were increasing, and, for the rest, there was insufficient data. The total estimate for all areas is between 22,000 to 31,000 bears, with Canada having between 60% to 80% of that population. The Committee on the Status of Endangered Wildlife in Canada consider polar bears to be a species of special concern that face an uncertain future due to threats posed by climate change.

Nunavut, part of Inuit Nunangat (the Inuit homelands in Canada) and one of Canada’s three northern territories, is home to twelve of the nineteen polar bear subpopulations. As my friend James Raffan says, bears are sacred and spiritual beings bound to the northernmost people in so many ways.

Nunavut’s Polar Bear Management Plan states: “Harvesting polar bears for meat, tradition, and economic benefit is still very important, and the harvest of one’s first bear is a significant milestone in a hunter’s life.” This management plan integrates Inuit societal values and traditional knowledge—collectively known as Inuit Qaujimajatuqangit—with ecological data. It acknowledges that bear distribution is shifting in response to changing ice conditions, which has forced bears to spend more time on land where they are more likely to interact with communities. Therefore, public safety is also an increasing concern.

Given what we know about how bears use the ice to hunt and live, and the rapid changes that are happening in the Arctic due to climate change, there is one thing I can say with some certainty about the future of polar bears: change is afoot. If you are planning a trip during which you hope to see polar bears, whether on land or at sea, sooner is probably better than later.