The tundra is a unique biome characterized by treeless, level or rolling ground found in Earth’s cold regions. A defining feature is permafrost, a layer of permanently frozen subsoil that prevents deep root growth and water drainage, often leading to boggy conditions in summer. Despite these harsh conditions, the tundra supports a diverse array of specialized plant and animal life.
Understanding Canada’s Tundra Regions
Canada encompasses extensive tundra regions, primarily Arctic and Alpine Tundra. The Arctic Tundra stretches across northern Canada, including Yukon, the Northwest Territories, Nunavut, northeastern Manitoba, northern Ontario, northern Quebec, and northern Labrador. This vast treeless expanse north of the boreal forest has long, dark, cold winters averaging -34°C, and short, cool summers from 3°C to 12°C. Precipitation is low, typically 15 to 25 centimeters annually, comparable to a desert.
Alpine Tundra is found at high elevations on mountains, including in Canada. These areas are above the treeline where temperatures are too low and winds too strong for trees to grow. While Alpine Tundra shares characteristics with Arctic Tundra, such as low-growing vegetation, its soil is generally well-drained due to the lack of continuous permafrost and steep topography.
Key Mammals of the Canadian Tundra
The Canadian tundra is home to various mammals. Polar bears roam Arctic coastal areas and sea ice, relying on thick blubber and dense fur for insulation. These apex predators primarily hunt seals, which they detect through scent.
Caribou undertake some of the longest terrestrial migrations, moving between wintering grounds in the boreal forest and summer calving grounds on the tundra. This allows them to access abundant seasonal food like lichens, sedges, and grasses, and provides protection for their calves from predators. Both male and female caribou grow antlers, a unique characteristic among deer species.
Muskoxen are well-suited to the treeless Arctic tundra, particularly on Canadian Arctic islands and northern mainland. Their defense strategy involves forming a protective circle with calves in the center when threatened, relying on their formidable horns and shaggy coats. These herbivores consume willows, grasses, and sedges, often digging through snow for forage. They possess two layers of fur, including a fine insulating undercoat called qiviut, which provides exceptional warmth in temperatures below -40°C.
Arctic foxes, with dense, multi-layered fur that changes color seasonally, are well-camouflaged for hunting small prey like lemmings and voles. Their small, rounded ears and short muzzles minimize heat loss. Arctic wolves, larger predators, hunt in packs, preying on caribou and muskoxen. Their thick coats and endurance enable them to traverse vast distances across the frozen landscape.
Lemmings, small rodents, are a foundational prey species in the tundra ecosystem, experiencing population cycles that influence their predators. They burrow under the snow in winter, creating insulated tunnels for foraging on vegetation and nesting. These small herbivores play a role in nutrient cycling and soil aeration in the fragile tundra environment.
Birds of the Canadian Tundra
Many bird species seasonally inhabit or permanently reside in the Canadian tundra. Snowy owls, distinctive for their white plumage, are formidable predators that hunt lemmings and other small mammals. Their silent flight and keen eyesight allow them to effectively ambush prey in the open tundra landscape.
Ptarmigans, including Rock and Willow species, are ground-dwelling birds known for seasonal plumage changes. Their feathers transform from mottled brown in summer to pure white in winter, providing camouflage against predators and insulation from the cold. Their feathered feet act like snowshoes, helping them move across snow and ice.
Various geese and duck species, such as Snow Geese and Common Eiders, migrate to the Canadian tundra during the brief summer to breed and raise their young. These birds benefit from abundant insect life and vegetation that emerges during the warmer months, building nests on the ground in sheltered areas. Their migration patterns are timed to exploit seasonal food availability and avoid the harsh winter.
Arctic terns are renowned for their incredible migratory journey, traveling from the Arctic to the Antarctic and back each year. They breed in the Canadian tundra, feeding on small fish and crustaceans in coastal waters. Their long, pointed wings and forked tails are adapted for efficient long-distance flight.
Other Notable Tundra Wildlife
Beyond mammals and birds, the Canadian tundra hosts a variety of other unique wildlife, including aquatic species and insects. Arctic Char, a cold-water fish related to salmon and trout, is found in the lakes and coastal waters of the Canadian Arctic. These fish can be anadromous, migrating to the ocean to feed before returning to freshwater to spawn, or they can be landlocked in freshwater lakes.
Insects, despite their small size, are a significant component of the tundra ecosystem. Mosquitoes and black flies, notorious for their swarms during the short summer, serve as a food source for many birds and some mammals. Bumblebees, such as the Arctic bumblebee (Bombus polaris), demonstrate adaptations to the cold, including generating internal heat by shivering flight muscles and possessing thick, insulating body hair. These bees pollinate the tundra’s low-growing flowering plants. Other terrestrial invertebrates, including various beetles, spiders, and worms, also inhabit the tundra, often living beneath rocks or in the thin active layer of soil, feeding on decaying vegetation or other small organisms.