The tundra ecosystems of the world can be found in the Arctic, Antarctic and alpine regions. These barren, desolate landscapes challenge life to find a foot hold and survive each day. One might expect the animals that have evolved to live on the tundra to have great difficulty in finding food. However these animals have adapted to life in the tundra so well that find food, especially when the weather is favorable, is not as difficult as one might expect. Let’s take a look at some of the more common animals to be found in the tundra regions and what their diets consist of.
Polar bears, with their thick white fur, sharp teeth and claws and powerful bodies are the ultimate tundra predators. They can be found in Alaska, Canada, Greenland, Russia and Norway. A polar bear’s diet consists largely of the birds, seals and walrus. From these animals the polar bear is able to extract valuable fats and oils to help it insulate it’s body and survive the long cold winters. A polar bear’s stomach can hold an estimated 15% to 20% of its body weight. A polar bear generally eats this much only when its energy demands are high. A bear can assimilate 84% of the protein and 97% of the fat it eats.
Penguins live in the Antarctic regions ( Southern Hemisphere ). The hunt in open seas or oceans eating fish, squid, krill or shrimp. The skin of a penguin is particularly thick and covers a layer of fat. This is an adaptation, much like that of the polar bear to help them survive the extreme cold climate of the antarctic tundra. The smaller penguin species of the Antarctic and the sub-antarctic primarily feed on krill and squids. Species found farther north tend to eat fishes. Penguins primarily rely on their vision while hunting. It is not known how penguins locate prey in the darkness, at night, or at great depths, Some scientists hypothesize that penguins are helped by the bio luminescence (light producing) capabilities of many oceanic squids, crustaceans, and fishes.
Musk Oxen are found in Canada, Greenland, Alaska and Ellesmere Island. Their diet is made up of grasses, lichens, sedges, woody plants, leaves and mosses. The fur of the musk oxen is around 3-4 inches thick and provides excellent heath insulation. Musk oxen are ruminants, animals with four-chambered stomachs. The rumen, the stomach’s first chamber, partially digests the food, which is then regurgitated, chewed further and then swallowed. The rumen is home to bacteria that ferment food, which releases additional caloric energy from the food source.
With their pure white winter coats and cute facial features, Arctic foxes are certainly one of the favorite Tundra based animals on the planet. The lives in dry and cold places such as Canada, Greenland and Alaska. Their diet comprises small mammals, lemmings, tundra voles, seabirds, and puffins. Their coats come in two ‘phases’ – a blue phase and a white phase. The Arctic fox is not endangered world wide and it is estimated that there are several thousand arctic foxes left in the wild. Two arctic fox populations are endangered, however. One in Russia has been reduced to around 90 animals because of a mange caused by ear ticks introduced by dogs. The second in Fennoscandia (Norway, Sweden, Finland, and Kola Peninsula) was caused by over hunting around the turn of the century. The total number of breeding pairs there is about 140.
Arctic hares can be found living in the tundra of Canada, on the Arctic island and also in Greenland. Being a vegetarian animal, Arctic hares survive on a diet of plants, mosses, lichens, buds, berries, leaves, seaweed, bark, willow twigs and roots. Arctic hares are sometimes loners but they can also be found in groups of dozens, hundreds, or even thousands of individuals. Unlike many mammals, arctic hare groups disperse rather than form during mating season. Animals pair off and define mating territories, though a male may take more than one female partner.
A predator, the arctic wolf will gladly prey on arctic hares, birds,caribou, musk oxen, lemmings, seals and sometimes try their hand ( paw ? ) at a spot of fishing too. Surprise attacks are almost impossible on the open tundra; by the time the pack approaches, its prey is in a defensive stance. Musk oxen, for example, will form a circle with their calves safely on the inside. The wolf pack must then try to disrupt the herd. The wolves circle the herd and prowl around, forcing the oxen to shift their ground to face them. If the wolves are successful, the oxen scatter. Once the herd has scatter, the wolves give chase, trying to isolate a young or weak animal. If one wolf catches a victim, the other will aid in killing it. A musk ox provides enough food to last the wolves for several days.
Snowy owls can be found in the Arctic tundra of North America and Eurasia. Theie habitat consists of open grasslands and fields and sometimes frozen expanses of water. They are also known to be found around the lake shores, marshes, and roost on buildings in cities and towns. In the Arctic regions, snowy owls usually nest on pingaluks (small , circular rises in the tundra grass-beds). Their diet includes mice, rats, hares, moles and other mammals;including rabbits. They also eats various birds (dove, grouse, quail) and water foul (ducks, grebes and medium sized geese). The Snowy can locate prey strictly audibly and may plunge in the snow for visibly hidden rodents like lemmings. It usually hunts from an elevated position that can vary from a raised knoll to a treetop or telephone pole along the edge of a field. It often makes long low flights to capture prey on the ground or birds from the water’s surface or pursues them in the air. It can hover and pounce on prey from the air or while on the ground. The Snowy is even said to catch fish, amphibians, and crustaceans.
Lemmings eat mostly plants such as mosses, grasses, herbs, shoots, and lichen. In summer, collared lemmings occupy the high, dry, and rocky areas of the tundra, where they shelter in shallow underground burrows or under rocks. Nesting chambers are often lined with dry grasses, feathers, and muskox fur. In the winter, lemmings may move to the lower meadow where the “blanket” of snow is thicker and remains for a longer period of time. Winter nests typically are built on the tundra surface, under the snow, and sometimes even in the middle of snow-banks.
Walruses are found in the region of Arctic seas from Alaska, Canada and Greenland to Russia. Their habitat is on open water, near to shore or on ice flows. Walruses primarily eat species that dwell on the sea bottom, such as mollusks, octopus, crabs, shrimp, salt worms, other crustaceans, shrimps, worms, some fish, clamps, mussels, other pinnipeds such as spotted seals. Because visibility is poor in deep and murky waters, walruses rely on their vibrissae to locate food. A walrus moves its snout along the bottom, rooting through the sediment. Abrasion patterns of the tusks show that they are dragged through the sediment, but are not used to dig up prey.Researchers have found numerous pebbles and small stones in the stomachs of walruses. They are thought to be ingested while feeding.
Caribou mostly eat ground and tree lichens. They also eat shrubs, grasses and willows. It takes 80 to 150 years for a forest to grow enough lichens for caribou. Like other deer and cattle, caribou have a four-chambered stomach capable of digesting the tough, fibrous plant and lichen materials containing cellulose that comprise most of their diet. Caribou ruminate, which means they re-chew forage that has previously fermented in the fore-pouches of their stomach.