Arctic Life/Arctic Animals/Arctic Amphibians
There have only been 5 amphibian species identified in the Arctic, none of which are circumpolar. The level of amphibian species richness in the Arctic is similar to that of deserts. Their limited presence in the North is largely due to the fact that amphibians' body temperature is determined by ambient conditions. Therefore, most of the world's 15,000 different amphibian species would freeze to death in these harsh, frigid conditions.
The Wood Frog, Rana sylvatica
The most northerly amphibian in North America, the wood frog has amazing freeze tolerance – it can survive even though much of its body fluids are frozen! Because of this adaptation, the wood frog has extended its range to the tree line, bordering on the Arctic. Perhaps climate is not what prevents this amazing animal from living even farther north, but simply the absence of its preferred habitat – damp, wooded areas. As its name suggests, the wood frog normally lives on the forest floor, stalking prey such as beetles or flies.
The wood frog is terrestrial most of the year, hibernating on land through the winter, and returning to ponds in the early spring while the ice is still present to mate. Males arrive first, and produce a feeble quacking call to attract mates. Several females lay their eggs together, forming a communal mass that attaches to vegetation at the water's surface.
Why Wood Frogs Shouldn't Wear Slippers
When hibernating, the wood frog's extremities slowly freeze solid, toes first. It is this freezing that triggers the physiological changes which protect the body core from freezing. Slippers would prevent the signal that changes are necessary. Without protection, freezing toes trigger the liver to pump glucose into the frog's body fluids. It is this sugar water that protects the frog by lowering the freezing point of its body fluids, pulling water out of its cells, protecting them from damage, and also providing an alternate source of energy.
Other arctic animals have different adaptations that allow them to survive the extreme conditions of this region. You can find out more about them by exploring the adaptation pages in each of the organism sections.
Why Are There No Arctic Reptiles?
Reptiles do not produce their own heat, but instead rely on heat sources in the environment. In frigid settings, "cold-blooded" animals like snakes and frogs simply never warm up. No reptile has evolved to survive the rigours of Arctic climate – but that is not to say that it is impossible! In fact, it is likely that at least a few reptile contemporaries of the dinosaurs managed to survive through conditions similar to that of the present day Arctic.
There is one snake, the common garter snake, Thamnophis sirtalis, whose distribution extends as far north as the southern border of tundra. This animal has an incredible ability to withstand low temperatures. It can tolerate temperatures of -5°C without freezing. When temperatures drop lower than this, it can survive with up to 40% of its body fluids turned to ice!
Although there are no true Arctic reptiles, there are many other kinds of animals that do inhabit the "top of the world", including a bat, bumblebees, and birds like the snowy owl. The waters are home to crustaceans, starfishes, anemones, jellyfishes, and a wide range of fishes. Many of these life forms are strikingly beautiful, unique, and often bizarre! An exploration of Canada's Polar Life is sure to reveal some surprises.
- "Amphibians and Reptiles". Conservation of Arctic Flora and Fauna (CAFF). Retrieved 26 August 2019.