Bros Deiv Blog: ANIMAL LIFE IN THE ARCTIC REGION

The Arctic is often described as a region of snow and ice surrounding the North Pole. A large part of the Arctic is composed of forested tundra where a large number of plants and animals live. The Arctic Circle rings the globe at 66° 33" north latitude, Arctic lands and oceans lie within this circle. North of this imaginary line lie the frozen lands of the Arctic. Seven countries share the Arctic—Canada, Finland, Greenland, Norway, Sweden, Russia, and the United States (Serreze et al., 2007).

The Arctic is large, almost equal in size to the entire continent of North America. Ironically, though most of the Arctic is made up of water it is technically a desert. Since the water is frozen most of the year, it is not accessible to plants or animals. Because of the extreme cold, the atmosphere is unable to hold enough moisture for it to snow or rain very much. In the summer, when the ice melts, water does become available in the lower Arctic regions. Since there is no drainage, it collects and pools to form huge wetlands. The layer of permafrost beneath the surface stays permanently frozen and does not allow water to percolate through the soil (Serreze et al., 2007).

Climate of the Arctic

It’s cold in the Arctic. Ocean water temperatures often stay below the freezing point of fresh water (0°C or 32°F). Dissolved salts and constant movement of the water keep it from freezing solid. On land, air temperatures average only 15.5°C (60°F) during the warmest months. During the winter, weather can be severe, with the temperatures falling to -70°C (-94°F). Strong winds can drop temperatures more. The annual snowfall compares to the snowfall of Chicago; about 30 to 60 cm (12–24 in.). Trees are rare, and plants grow low to the ground. Because the Arctic is at the “top” of the world, the sun may never rise above the horizon on some winter days and may never set below the horizon on some summer days. For example, in December, some days may be 24 hours dark, but in June some days may be 24 hours light. Portage Glacier in the Kenai Peninsula slowly moves down the mountainside, releasing ice and snow decades old to the sea (Addison, 2002).

Biota of the Arctic

There are numerous species of plants and animals that live in the Arctic. South of the Arctic tree line lies the Boreal forest which is comprised primarily of coniferous trees such as spruce, fir and larch. To the north of the tree line, there are many low growing herbs, forbs and shrubs such as heath, lingonberries, bilberries, blueberries, arctic poppies, tundra grasses, lichens, mosses, birch and willow shrubs. There are also several different species of animals, including lemmings, Arctic hares, Arctic fox, polar bears, caribou, musk ox, ptarmigan, snowy owl, Arctic tern and many others (Grinberg, 2008).

Animals in the arctic region includes; Land Animals: Polar bear, wolf, musk ox, Arctic fox, snowshoe hare, wolverine, weasel, lemming, moose, elk, reindeer. Marine animals; walrus, seals, whales, sea otters. Birds; Raven, ptarmigan, geese, ducks, swans, phalarope, gulls, horned lark, snow bunting, Arctic tern, skua (Toledo Zoo, 2000). Shrimps, fishes, seals, walruses, and whales thrive in the cold, nutrient-rich waters of the Arctic Ocean. Caribou, moose, and musk oxen roam the tundra. Polar bears prowl the ice. Birds such as ptarmigans and snowy owls live year-round in the cold weather. Many other animals visit arctic lands to feast on summer plants and insects. Some birds, seals, and whales migrate south during the coldest arctic months. Others stay year-round, protected by thick layers of blubber or dense coats of fur. The arctic fox and grouse change colors; they are brown in summer, white in winter (Toledo Zoo, 2000).

Polar Bear Adaptation and Survival in the Arctic

The polar bear is the most carnivorous member of the bear family, and most of its diet consists of ringed and bearded seals. The Arctic is home to millions of seals, which become prey when they surface in holes in the ice in order to breathe, or when they haul out on the ice to rest. Polar bears hunt primarily at the interface between ice, water, and air; they only rarely catch seals on land or in open water. The polar bear's most common hunting method is called still-hunting. The bear uses its excellent sense of smell to locate a seal breathing hole, and crouches nearby in silence for a seal to appear. When the seal exhales, the bear smells its breath, reaches into the hole with a forepaw, and drags it out onto the ice. The polar bear kills the seal by biting its head to crush its skull. The polar bear also hunts by stalking seals resting on the ice: Upon spotting a seal, it walks to within 90 m (100 yd), and then crouches. If the seal does not notice, the bear creeps to within 9 to 12 m (30 to 40 ft) of the seal and then suddenly rushes forth to attack. A third hunting method is to raid the birth lairs that female seals create in the snow.

Polar bears are uniquely adapted to the harsh Arctic environment. It may be one of the toughest places on Earth to survive but to a polar bear, its home. And since the sun never sets during summer in the Arctic, bedtime is anytime.

With the exception of pregnant females, polar bears are active year-round, although they have a vestigial hibernation induction trigger in their blood. Unlike brown and black bears, polar bears are capable of fasting for up to several months during late summer and early fall, when they cannot hunt for seals because the sea is unfrozen. When sea ice is unavailable during summer and early autumn, some populations live off fat reserves for months at a time. Polar bears have also been observed to eat a wide variety of other wild foods, including musk ox, reindeer, birds, eggs, rodents, shellfish, crabs, and other polar bears. They may also eat plants, including berries, roots, and kelp, however none of these are a significant part of their diet. The polar bear's biology is specialized to require large amounts of fat from marine mammals, and it cannot derive sufficient caloric intake from terrestrial food (Eliasson, 2004).

Being both curious animals and scavengers, polar bears investigate and consume garbage where they come into contact with humans. Polar bears may attempt to consume almost anything they can find, including hazardous substances such as Styrofoam, plastic, car batteries, ethylene glycol, hydraulic fluid, and motor oil (Eliasson, 2004).

Other Land mammals in the Arctic

Moose, unlike most Arctic animals, have long legs. These are helping for stepping in the snow, but could cause it to lose a lot of body heat.

Caribou often migrate long distances to avoid the cold and search for food and shelter. They have broad hooves that splay out and help them walk across the snow. The hooves also help them swim and to dig in the snow to find plants buried below.

Many small mammals, particularly rodents like the ground squirrel, hibernate during the winter. Hibernation means they rest- almost like sleeping- for many weeks or months without eating, drinking or even waking up! Their body temperature drops and they live off of stored fat. Many people think of bears when they think about hibernation, but most bears don’t really hibernate. They get up several times throughout the winter to forage for food, and some females give birth during this time.

Arctic hares have very short ears and legs to prevent heat loss. They also have large padded feet that act like snowshoes to help them hop across the snow. In spring, hares are brown with black flecks, but in winter, they change to all white. The color change serves as camouflage to protect it from predators.

Ptarmigans remain in the Arctic year round. They change color from brown in the spring to solid white during the winter. The color change helps to protect them from hungry predators. To keep warm, they have water-repellent outer feathers in addition to inner feathers. They even grow feathers on the soles of their feet to keep their feet warm and serve as snowshoes to prevent them from sinking in the snow! Another solution to staying warm is to take flight and dive into drifts of snow. The snow acts like a blanket and traps heat from the ground (Ulfur et al., 2006).

Other birds deal with the cold winters by avoiding the situation all together. As winter approaches, birds like the Red throated Loon and Arctic Tern migrate south to warmer regions.

The Arctic Tern is an amazing bird in that every year it migrates all the way from the Arctic to the Antarctic. That’s over 22,000 miles (Jeff et al., 2007).

Unlike seals and other mammals, fish do not keep their body temperature much higher than the water around them. The important thing is for the fish to keep ice crystals from forming inside their body, because ice builds quickly once it starts. Therefore, some fish have a protein in their blood that acts like antifreeze in a car. It binds to ice crystals, isolating them from each other so they can’t grow (Ulfur et al., 2006).