In summer, the tundra buzzes with energy and life, but in winter, conditions on the same northern landscape are daunting, and it appears quite desolate and bleak. Despite the harsh climate and long, frigid darkness of winter, a variety of animals from polar bears and Arctic fox to ptarmigan and snowy owls have adapted their behavior and instincts to subsisting in the region year-round. About 40 mammal species live in and around Churchill (half are marine mammals), and approximately 100 bird species breed here.
Click on the links below to navigate to each species.
Polar Bear | Caribou | Ringed Seal | Bearded Seal |
Arctic Fox | Willow Ptarmigan | Snowy Owl
The polar bear (Ursus maritimus) is the largest member of the bear family. Females grow until they are about four years old and attain a maximum weight of approximately 660 pounds. Males continue to grow until eight years of age, weighing on average from 1,100 to 1,300 pounds and measuring between eight and 11 feet from nose to tail. The largest recorded polar bear was a male measuring more than 12 feet tall and weighing a reported 2,210 pounds!
The polar bear’s stocky body has a longer neck and proportionately smaller head than other bears. Its powerful musculature is particularly well developed in the hind legs and neck. Its massive forepaws, up to 12 inches in diameter, are larger than the hind paws and are oar-like, with partially webbed toes for more efficient swimming. The soles of the feet are covered with dense pads of fur, offering better traction on ice. The bear’s short tail is inconspicuous, and its ears are small and furry.
A polar bear has excellent eyesight and hearing, and its nose is so incredibly sensitive that it can detect a seal more than 20 miles away! Researchers in Alaska have watched male polar bears march in a straight line, over the tops of pressure ridges of uplifted ice and through open leads, for up to 40 miles, in order to reach a prey animal they had detected. These bears can also sniff out seal dens covered by three feet of ice and snow.
An adult bear’s stomach is very large, with a capacity to hold more than 150 pounds of food. The polar bear’s liver is extremely rich in vitamin A, ranging between 15,000 and 30,000 units per gram, which makes it toxic to humans; there are accounts of Arctic explorers who became ill or even died from vitamin A poisoning after eating it.
The polar bear is the king carnivore of the Arctic. Eating almost exclusively meat, its diet is comprised primarily of sea mammals, particularly ringed seals—the most abundant mammal in the Arctic—which provides the high fat content polar bears need to thrive. They also prey on bearded seals and occasionally walrus, beluga whale and narwhal. They may supplement their diet with coastline carrion, including crabs, fish and marooned whales, as well as geese, bird eggs and small mammals.
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A polar bear’s hunting and eating patterns are completely dependent on sea ice. Sniffing out a seal breathing hole, the bear remains motionless, yards away, or along a lead edge waiting for a seal to surface. When the seal rises, the polar bear bites onto the head or upper body, then flips the entire seal onto the ice. They also stalk ringed seals sleeping on the ice, slowly crawling forward and freezing in place till they are ready to make an explosive pounce from 30-50 feet away, killing the seal before it can slip back into the sea.
During their time on the ice, polar bears survive off their fat reserves for long stretches after gorging on seals. Because of their giant stomachs, polar bears can devour a huge amount of food—up to 150 pounds—at one sitting. This allows them to take full advantage of any temporary windfall. They must, however, eat at least one seal every five to six days to preserve their body weight.
When the summer thaw occurs, polar bears must head ashore where they meander the coastline in search of food. They will consume anything edible, including eggs, reindeer, carrion, and even plants and berries. Even with the addition of this assortment of foods, polar bears lose weight in summer and early autumn as they subsist primarily on stockpiled fat. They are simply too large to receive much energy from small morsels like Arctic hare or fish. And as the seal-hunting season continues to shorten in a warming Arctic, with freeze-up happening later and pack ice melting earlier each summer, polar bears may struggle to retain enough fat stores through the long summer seal fast.
For eons, indigenous cultures have relied on the "deer of the North" for food and clothing. A wealth of caribou would bring celebrations and feasting, while a scarcity meant famine and hardship. An iconic symbol of the North, this social herd animal—equally comfortable in the boreal forest and on the open tundra—makes more extensive migrations and occurs in larger herd numbers than any other North American land mammal.
Though they often follow similar migration patterns and frequent the same seasonal ranges, caribou can be unpredictable and diverge from their traditional routes. During summer, however, they tend to head to the coast where tidal flats offer a respite from the ubiquitous black flies of the interior.
Both sexes of caribou have antlers, a fact that differentiates them from all other deer species. The shape of each animal’s antlers varies significantly, and many believe that no two pairs of antlers look the same. Adult bulls shed their large antlers early in winter, but cows retain theirs until June when calving time arrives. This way, pregnant females can claim and protect optimal feeding areas through the winter when getting food of the highest quality is imperative to nurturing their quickly developing fetuses.
Numerous critical adaptations enable caribou to endure,
and even prosper, during lengthy, frigid winters. The caribou maintains two different internal temperatures to avoid dangerous loss of heat from its lanky legs. While its core temperature stays near 105°F, its legs stay at least 50 degrees colder because
the arteries and veins of the caribou run right next to each other, meaning that the out-flowing arterial blood transmits its warmth to the chilled, venous blood returning from the limbs. The blood vessels in the caribou’s extremities allow just enough blood to flow so they lose very little valuable body heat to the chilly, ambient air, and their legs do not succumb to frost damage.
The caribou’s coat, made of dense, hollow club-shaped hair, shields the animal, including its feet, tail
and muzzle, from extreme temperatures. These hairs, which have thicker tips than bases, create a coat with a thin, curly underwool and a thickly packed outside layer that has countless small spaces of air. With this extremely warm coat, caribou become
practically invincible to even the nastiest Arctic weather. Because of all the adaptations that have made caribou able to thrive in the Arctic, some scientists refer to them as chionophiles, or "snow lovers."
Giant feet that act as snowshoes allow caribou to stay on top of soft snow, another necessary adaptation for this environment. Their wide, sharp hooves also allow them to effortlessly break and clear snow when they dig craters in search of food.
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Reaching population levels near 6 or 7 million, the ringed seal is the most plentiful, pervasive and common seal of the Arctic. It is the most significant seal supporting the diet of indigenous peoples who inhabit the Northwest Territories. Living in the Northern Hemisphere’s circumpolar regions, the ringed seal gravitates to habitats comprised of pressure ridges, leads
and polynyas in the Arctic Ocean’s land-fast ice, which is sea ice that forms in shallow water off the coast.
Compared to other seals, ringed seals are small. Males typically weigh between 145 and 200 pounds and measure slightly more than 4 feet long, while females average 100 to 110 pounds. Rigid guard hairs comprise their light gray coats, which can display varied patterns, but always have black spots surrounded by lighter ring markings (giving them their name). Spots on their backsides often merge with each other so they appear like a stripe instead of a spot. Their undercoat is lighter and their bellies are usually clear, silvery-white to creamy yellow, and scattered with black spots.
Using their well-honed sense of smell, hearing
and vision, curious ringed seals often investigate unknown sounds and sights. Lounging seals continuously alternate between lying flat and lifting their heads skyward for a few moments. They utilize a variety of vocalizations including moans, whines, and growls, and they frequently heed cautions sent by other seals.
Though they periodically group up at haul-out areas or move in groups that are loosely organized, ringed seals are chiefly solitary beings. During winter, they separate according to age; adults stay in preferred breeding habitats, under stable ice in bays and fjords, while non-breeders remain at the edge of the floe where they move based on availability
of food and population pressures.
In the water, seals utilize holes within the ice for breathing; they keep these holes open by using their fore flippers to claw the ice. Cone-shaped and covered with an ice dome perforated by a tiny vent, seals can hollow out the breathing hole if snow blows over it. Prior to surfacing, seals may blow bubbles through the hole to check for predators.
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The bearded seal is a primary food source for polar bears and for the Inuit of the Arctic coast. Holding a place of esteem in the area, the native name for the seal is ugyuk
, and its skin is used to cover the traditional wood-frame boats known as an umiak
. The bearded seal gets its generic name, Erignathus barbatus
, from two Greek words that refer to its heavy jaw. In addition, the seal’s name refers to its most characteristic feature: conspicuous and very abundant whiskers.
Entirely gray, with a darker back and dappled in tiny, dark spots, bearded seals are big animals; males and females measure more than 7 feet long and weigh approximately 570 pounds. As their name indicates, bearded seals have elongated whiskers covering their chin and nose. Bearded seals share some characteristics with monk seals. Most seals have beaded whiskers, but both bearded and monk seals have smooth whiskers. And, while other seals have two nipples, bearded and monk seals both have four.
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The Arctic is a harsh environment in which few species can survive. The Arctic fox, a specialist at adapting to circumpolar regions, is an exception. Only as big as a large domesticated cat, this canine is one of the tiniest mammals to actively spend the long Arctic winter above the surface of the snow.
In winter, the Arctic fox looks bulky and rounded due to its long, thick, soft fur coat. Underneath their fur is a rather skinny body, and they typically weigh just 10 pounds. Despite living in temperatures that reach –20°F and lower, Arctic foxes are able to maintain their core temperature due to adaptations that include a short muzzle, legs and ears, and densely furred footpads. Using its keen hearing and profound
sense of smell, the Arctic fox can detect lemmings, an important food source, scurrying under the snow’s surface. Living on the coast and offshore ice, the Arctic fox is a more skilled swimmer than other canines. Its shrill bark is easily identifiable, but the Arctic fox also periodically purrs in a cat-like manner.
Arctic foxes are dimorphic, which means they can exhibit one of two phases—brown or white. They are the lone canine to undergo a change in coat color from summer to winter. The white Arctic fox begins molting in early July to expose its summer fur, which is fawn-colored and brown. After approximately eight weeks, they begin to regrow their white coat for winter. Blue phase foxes have a pale grey coat in winter and a dark bluish one in summer. Though the reasons aren’t totally clear, the coastal populations of Jan Mayen Island, West Greenland, the Commander Islands and the Pribilof Islands are usually blue, while 99 percent of the continental foxes living on the mainland of Canada are
During winter months, Arctic foxes do not hibernate. They exhibit a combination of nomadic and communal behavior, typically establishing small groups to search for food. These foxes usually construct dens in a rock mound at a cliff base or in stumpy knolls, 3 to 13 feet high, on the tundra. Some of these complex dens—with between four and eight entrances and a tunnel system that can reach over 300 square feet—have provided shelter for multiple generations of foxes, since they are used over and over for centuries. Each den, usually built in cliffs a minimum of a mile apart, houses a family—a social group comprised of the litter, a male adult, and two vixens. Born the previous year, one of these females is non-breeding but remains to assist in caring for the new litter.
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With squat, rounded wings and a slight black bill, this stout bird resembles a chicken. Reaching 15 to 17 inches long, the willow ptarmigan is the biggest of the three species of ptarmigan. Males weigh in at just over one pound and females weigh a little less. The red comb above their eyes and the square tail that remains black all year distinguish this bird from other ptarmigan. Females, which are more gray-brown, display heavy breast and flank barring while mature males have brilliant red "eyebrows."
Thick feathers cover the willow ptarmigan’s legs and hide its nostrils to prevent snow from getting in. In autumn, ptarmigan also grow a solid clump of rigid feathers over their toes. These feather-covered feet act like snowshoes in winter, while their sharp, elongated claws assist the bird with crossing icy slopes. The snowy owl is the only other bird that is as well suited to survive unforgiving winters in the Arctic.
The ptarmigan’s plumage is in harmony with the colors dominating the landscape. In winter, ptarmigan are snowy white, but in late spring, they morph to piebald, a combination of summer brown and winter white. In summer, they turn deep tones of gray and brown, blending in with the ground. In fall, they turn speckled brown, white and gray before returning to a dazzling white in time for snow to cover the earth again.
Apparently conscious of their camouflage, they tend to gravitate toward surroundings that match their color so they can remain unnoticed by predators. For instance, white ptarmigan are extremely unwilling to travel across dark
ground. Likewise, birds dressed in summer brown do their best to cross dark ground while circumventing snow patches. This strategy helps ptarmigan remain inconspicuous year-round, with the exception of spring when males fervently court females.
Though willow ptarmigan spend the majority of time on the ground, if they are startled, they burst into strong, swift flight and can cover a mile prior to landing. Because snow provides excellent insulation from the cold and offers a place to hide from predators, ptarmigan prefer to sleep under the snow. For this reason, you may see a ptarmigan flying straight into a snow bank; if it were to walk, a predator, such as a fox, may be able to trace its tracks.
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Weighing a little more than 3 pounds, measuring between 24 and 29 inches long, and boasting a 5.5-foot wingspan on average, this powerful bird is the largest Arctic bird species. In this sexually dimorphic species, females are heavier and larger than males. Snowy owls are chiefly white, but they have dusky flecks and bands of dark brown cutting across their plumage. More predominant in immature birds, these bands are barely noticeable on males, and many older males are totally white. Snowy owls have yellow eyes and white feathers, which offer protection from the frigid Arctic weather, enveloping their feet and legs.
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