Sunlight in summer
Arctic land temperatures in winter
Age of some Arctic willow forests
Summer temperature in the Arctic
Animals found in the Arctic include ringed, harbour, harp, hooded and northern fur seals, walruses, polar bears, bowhead whales, belugas, narwhals, Greenland sharks and about 100 species of fish. Many bird, insect and non-marine mammal species also live in the Arctic.
Most whales and other marine mammals avoid the harsh winters and migrate to warmer waters. However, seals remain in the ice-covered waters. In the fall, while the ice is rubbery, the seals push up against the ice with their heads to form a shallow dome filled with air. During the winter, they will return to these domes to breathe—keeping it clear of new-forming ice. In spring, these domes are enlarged by the female seals to create a safe place for giving birth to pups.
Trees do not thrive in the Arctic because the permafrost prevents their roots from extending into the soil. Without a firm anchor, the harsh, icy Arctic winds can topple large trees. The permafrost also limits the amount of nutrients that are available to the trees. To make matters worse, the Arctic has a very short growing season, preventing large trees from storing enough nourishment to survive the long winter. In spite of these harsh conditions, some parts of the Arctic are home to willow forests. These forests, found in Arctic Alaska, can reach a height of five to seven meters and some are 400 years old.
Belugas as a species are not endangered, but COSEWIC (Committee on the Status of Endangered Wildlife in Canada) has listed the St. Lawrence beluga population as being endangered. There are currently fewer than 500 individuals and their numbers continue to drop. This may be caused by high levels of pollution and boat traffic in Quebec’s St. Lawrence River. Toxins dumped into the water end up concentrated in the beluga’s fat. Fat is the main ingredient of the beluga mother’s milk that feeds the calves so this further concentrates the toxins in the next generation. Boat traffic is another factor contributing to the decline of belugas because their noise masks out the sounds belugas use to find food, breathing holes in the ice (in the Arctic region), and each other.
Heat loss happens 25 times faster in water than in air, so you get cold much more quickly. Belugas, seals and other marine mammals have thick layers of fat (blubber) to help them keep warm. This blubber insulates the animals and keeps them warm in the near 0°C temperatures. It also provides an energy reserve. Seal blubber can be 5-7.5 cm thick and the blubber of a bowhead whale can be up to 60 cm thick. Other Arctic marine animals and fish have a substance similar to “antifreeze” in their blood (glyco-protein) that keeps them from freezing.
Fur and fat are common among other Arctic residents. Musk oxen and Arctic foxes both have dense winter coats, and the musk ox has insulating fat. The Arctic foxes' short legs, ears and muzzle help to limit heat loss. Polar bears have blubber, thick fur and an outer coat of porous hairs to keep them warm. The porous hairs trap air, which is then heated by the bear’s body, insulating the bear from the cold. The ptarmigan has feathers that increase in density during the winter when they burrow into the snow to reduce heat loss.