Amphibians

The subarctic is a tough terrain for cold-blooded creatures like amphibians where they rely on their environment to regulate body temperature. For this reason, we see few of these animals in Wapusk National Park. Just two amphibians have become specially adapted to make the subarctic their home: the wood frog (Lithobates sylvaticus) and boreal chorus frog (Pseudacris triseriata maculata). These two frogs share one of the most unique adaptations in the world, a special cellular mechanism that allows them to survive the extreme cold of subarctic winters. When the winter season comes, these frogs burrow into the abundant peat moss of Wapusk National Park and in their winter home they freeze completely solid. A special process that involves flooding their cells with glucose allows these frogs to survive the freezing process and enter a winter hibernation. Come spring, the frog thaws out with the active layer of the ground and finishes its hibernation.

In Wapusk National Park, both of these frogs can be quickly identified by their distinct calls. The boreal chorus frog is sometimes said to make a sound similar to the one that is produced when you run your fingers over a comb, while a wood frog sounds close to a duck’s quack. If you are able to see these two up close, identifying which is which can be tricky. Both frogs are small and come in a range of shades from green to brown. If you’re able to get a close look, the wood frog can be distinguished by a black mask surrounding each eye, while the boreal chorus frog has a dark stripe that starts at the snout but extends down its side. Both these frogs live in similar habitats in Wapusk National Park, frequenting the many ponds that cover the park. These ponds are hotspots for various species of bugs that both frogs prey on, and provide an excellent spot of standing water where the frogs lay their eggs and the hatched tadpoles are able to live largely undisturbed.

As a part of the largest wetland network in North America, Wapusk National Park offers prime habitat and food sources for both the wood frog and boreal chorus frog. It is because of these frogs’ special adaptation to survive the winter that they have found their niche in the subarctic ecosystem.