The tundra is a treeless biome characterized by extremely cold temperatures, low precipitation, and short growing seasons. It exists in two primary forms: the Arctic tundra, found in the Northern Hemisphere, and the alpine tundra, located on mountains worldwide at high altitudes. A defining feature of the Arctic tundra is permafrost, a layer of permanently frozen ground that prevents deep-rooted vegetation from growing. Despite these harsh conditions, both types of tundra support a variety of life forms with specialized adaptations for survival.
Animals of the Arctic Tundra
Arctic tundra animals have adaptations like thick insulation, camouflage, and unique behavioral strategies to cope with extreme cold and limited food.
The Arctic fox ( _Vulpes lagopus_ ) is well-suited to this environment. Its dense, woolly coat provides insulation, and its fur color changes seasonally from white to brownish-gray, providing camouflage. The fox’s compact body, short legs, small ears, and short muzzle minimize heat loss, while fur on its feet offers warmth and traction. Arctic foxes are opportunistic hunters, relying on hearing to locate prey like lemmings beneath the snow.
Caribou ( _Rangifer tarandus_ ), also known as reindeer, inhabit the Arctic tundra. They undertake annual migrations, sometimes traveling thousands of miles. Caribou have a double-layered coat with hollow guard hairs that trap air, providing insulation and buoyancy for swimming. Their large, crescent-shaped hooves act like snowshoes to distribute weight on snow or soft ground, and they dig for lichen, a primary winter food source. Their muzzles are covered with hair, and nasal passages warm incoming cold air.
Musk oxen ( _Ovibos moschatus_ ) are large, hoofed mammals known for their thick, shaggy coats. Their outer layer of long guard hairs covers a dense, woolly undercoat called qiviut, one of the warmest natural fibers. This fur, along with a compact body, short legs, and a thick layer of fat, helps them conserve heat in temperatures as low as -40°C. When threatened, musk oxen form a defensive circle around their young, presenting a barrier of horns to predators. They survive on sparse tundra plants, using their hooves to dig for food under the snow.
The snowy owl ( _Bubo scandiacus_ ) is a large, predominantly white raptor adapted for life in the open Arctic. Its thick plumage, including feathers on its feet, provides insulation against the cold. These owls have keen eyesight and hearing, allowing them to spot prey like lemmings from significant distances or under snow. Unlike most owls, snowy owls are diurnal, hunting during the extended daylight hours of the Arctic summer. Their silent flight, aided by a large wingspan, helps them surprise prey.
Animals of the Alpine Tundra
The alpine tundra, found at high elevations on mountains globally, presents unique challenges, including steep terrain, strong winds, and fluctuating temperatures. Animals here exhibit adaptations for climbing, burrowing, and efficient energy use.
The mountain goat ( _Oreamnos americanus_ ) is a sure-footed climber inhabiting rugged, rocky slopes. Its hooves are adapted for climbing, featuring inner pads for traction and cloven toes that spread for grip. Sharp dewclaws prevent slipping. Mountain goats have a thick, woolly double coat that protects them from cold, wind, and precipitation. Their strong legs and muscular shoulders enable them to navigate steep terrain and jump considerable distances.
Marmots ( _Marmota_ species), such as the alpine marmot, are large ground squirrels common in alpine regions. They spend significant portions of the year hibernating in underground burrows, a strategy to conserve energy during cold, food-scarce winters. These burrows, often passed down through generations, provide insulation. Alpine marmots are social animals, often hibernating in family groups, which helps them retain body heat through physical contact. They accumulate fat reserves during the summer to sustain them through their long hibernation period.
Pikas ( _Ochotona_ species) are small, rabbit-like mammals that do not hibernate. Instead, they collect and store large quantities of vegetation, known as “haypiles,” during the summer. These haypiles, cured by the sun, serve as their primary food source throughout the winter when fresh forage is unavailable. Pikas also utilize rocky crevices and boulder fields for shelter, where thick snowpack provides insulation against extreme cold. Their furry paws and thick coats offer additional protection.
The golden eagle ( _Aquila chrysaetos_ ) is a large raptor found in open and mountainous habitats, including alpine tundra. These birds have excellent eyesight, allowing them to spot prey from high altitudes over vast landscapes. Their broad wings and strong flight enable them to soar efficiently on air currents, covering large territories in search of food. Golden eagles hunt a variety of medium-sized mammals and birds. Their sharp talons and strong beaks are well-suited for capturing and dismembering prey in their mountainous environment.