The Arctic Tundra Habitat
In this article, we will learn about some of the animals that live in the arctic tundra. The arctic tundra is a large area that lies between the north pole at the top of the world, and the coniferous forests that grow at lower latitudes. The arctic tundra includes the northern parts of Canada and Alaska, Scandinavia, and Siberia.
Survival is not easy in the arctic tundra. The tundra is usually very cold. The average annual temperature is -19 degrees Fahrenheit. It is also very dry, receiving less than ten inches of precipitation annually. Most tundra vegetation consists of low-growing plants such as mosses, lichens, and grasses. There are a few shrubs, but there are no trees because the ground is permanently frozen at or just below the surface. This frozen layer is called “permafrost.” The arctic tundra is cold and dark in the winter. During the summer season, which lasts only six to ten weeks, the snow and the top layer of the permafrost melt. Insects and migrating birds are attracted to the marshes, bogs, and streams that form when the surface ice melts.
The arctic tundra is home to 48 species of land mammals. Most animals that live in the tundra have special characteristics that allow them to survive in their harsh environment. For example, some animals migrate, while others hibernate. Each species generally occurs in large numbers. There are rodents, shrews, foxes, hares, bears, musk ox, wolves, and deer. Huge herds of caribou feed on lichens and other plants. Some of the migrating birds that spend their summers in the arctic tundra are harlequin ducks, arctic terns, snow geese, and tundra swans. During the summer, there are also swarms of flies, mosquitoes, and tiny biting midges called “no-see-ums.”
The caribou is a large member of the deer family. Both male and female caribou have antlers, but the male caribou’s antlers are much larger. The coat of the caribou is brown, becoming darker in the summer and lighter in the winter. The fur around the hooves and above the tail is nearly white. Caribou fur is very soft and warm; it sheds water and snow. The caribou’s hollow hairs and the thick layer of fat under its skin insulate its body, holding in heat and helping it survive cold temperatures.
Adult males can weigh as much as 700 pounds. Their large, wide hooves help support their weight on the snow in the winter and on the marshy ground in the summer. During the winter, caribou sweep the snow away with their antlers and feet to eat lichens, sedges, and small shrubs. During the summer, they eat willows, sedges, mushrooms and other plants.
Caribou live in large herds that can include thousands of individual animals. Caribou herds stay on the move to find food and to get away from biting insects. They will migrate as far as 500 miles to reach winter or summer feeding grounds, traveling up to fifty miles per day. Their breeding season begins in September and extends through October. Pregnant females lead the migration to the spring calving grounds in May, where the cows give birth to single calves.
Caribou and reindeer are the same species. Reindeer have been domesticated in Europe and Asia for centuries. Reindeer were released in Alaska in 1887, where they are now known as caribou.
The fur of the arctic fox is warmer than polar bear or wolf fur. Its long fur is usually white in the winter and brownish-grey in the summer. Some are a blue-grey color, but white is more common. Blue foxes stay dark-colored year round, although their fur does get a little lighter in the winter. The fox can wrap its long, bushy tail around itself to help keep warm during the winter. Its compact body, short legs and ears, and furry footpads also help keep the fox warm.
The arctic fox is about the size of a house cat, weighing from six to ten pounds. It hunts for small prey such as lemmings, but also finds food by scavenging. Sometimes it follows polar bears and other predators to eat the scraps they leave behind. It will eat almost anything, and sometimes buries extra food to eat later.
The arctic fox lives in small burrows where the ground is not frozen, usually in low mounds or rock piles. The mating season is in March and April. Litters average seven pups, but can include as many as fifteen. Life on the tundra is hard, and most of the pups do not reach adulthood. Those that survive may live to be fifteen years old.
Polar bears have fur that grows in two layers, which keeps them very warm. The individual hairs are actually clear, not white. The light reflected off of snow makes their fur appear white. They have black noses and eyes, and their skin is also black. Because of their unusual fur, most of the sun’s rays reach their black skin, which helps them keep warm. Their thick layer of blubber holds in heat as well, allowing them to swim comfortably in icy water. Their short ears and tails also help reduce heat loss.
Polar bears are the largest predators that live on land. In fact, they are some of the largest mammals on Earth. Adult male bears can weigh over 1,000 pounds, and can stand up to ten feet tall. Females are smaller, averaging less than 700 pounds. Polar bears usually live near open water with ice floes where they can hunt seals, their favorite food. Occasionally, they will also eat walruses or the carcasses of dead whales. In the summer they may also eat arctic foxes, lemmings, ducks, and even plants. Their sharp teeth and claws help them catch their prey.
Polar bears have dens where they will occasionally sleep, and where the females have their cubs, but they do not hibernate. A female bear will only produce cubs once every two or three years. Mating season is in the spring. In the winter, the females give birth to one or two cubs. The cubs stay with their mothers for more than two years. During that time, the mothers teach the cubs to hunt.
Musk oxen have fur with two layers that are specially adapted to help keep the animals warm. The outer layer consists of long, brown hairs up to two feet long. The inner layer, called “qiviut,” is a kind of wool. The muzzle is usually white. Their spreading hooves help them walk on the snow and soft ground without sinking. Their large, hard hooves also help them break ice so they can find water to drink.
Musk oxen can weigh up to 900 pounds, and may stand five feet high at the shoulder. They will eat most of the vegetation that is available in the tundra, including lichens, grasses, and shrubs.
Musk oxen live in herds averaging from ten to twenty animals, roaming their range in search of food and water. They may travel 50 miles between their summer and winter feeding grounds. Each herd has a dominant male that will mate with all the females during the late summer and early fall. The females give birth to single calves in the spring.
Both males and females have horns. Where the horns meet, near the center of the skull, males will also grow a heavy boss. Musk oxen live farther north than any other hoofed animal. At one time they were eradicated from Alaska, Norway, Sweden, and Russia, but they have been successfully reintroduced there. Musk oxen are named for the odor produced by a pair of glands that the males have beneath their eyes. When threatened, the adult musk oxen will form a protective ring around their young, facing their enemies on the outside of the ring.
Arctic hares have a coat that is white in winter, and gray or brown in summer. The tail remains white all year. Their ear tips are black, and relatively small to conserve heat. Their large hind feet help them move quickly across snow.
Arctic hares are about two feet long and weigh about ten pounds. They eat lichens, berries, twigs, moss, woody plants, and other vegetation. During the winter, their main food is willow. Their claws help them dig through the snow to find food.
Arctic hares mate in early spring. Females have their litters from June through early July. Litters average five babies, called “leverets.” The mother will line a small dent in the moss or grass with fur to make a nest for her leverets. By the time they are a month old, the babies are ready to be weaned. By the time they are two or three months old, they are as large as an adult.
Hares will sometimes live in large groups. Some act as lookouts while the others rest or eat. They can reach speeds of almost 40 miles per hour. They can also swim short distances.
As you can see, there are quite a few species of animals that live in the arctic tundra that are able to adapt themselves to the unusual weather conditions associated with this region. The biodiversity of the arctic tundra is truly amazing indeed.