Cold-blooded in a cold climate
As the forest comes alive in the spring, we often stop to enjoy the sound of birds calling in the trees. The ponds and lakes melt out, and the ducks are aggressively quacking. But wait … Those aren’t ducks; that quacking you hear is from wood frogs.
The Yukon is technically home to three species of frog and one toad. But, realistically, you’ll only ever come across the wood frog. The other three species of Yukon amphibian—the boreal chorus frog, the Columbia spotted frog and the western toad—have ranges that barely dip into the Yukon’s southernmost regions. If you’re exploring along the Yukon-B.C. border, keep an eye out for these other species.
However, wood frogs range as far north as the Old Crow Flats. They are found all over the Yukon in a variety of habitats, from ponds to lakes and forests. They’re highly adaptable and it’s not unusual to find them a kilometre away from water. As adults, wood frogs are carnivorous—hunting insects, worms, snails and fish with their long tongues. But as tadpoles, they are strictly herbivorous, eating only aquatic plants.
Cold-blooded in a cold climate
Wood frogs thrive in the North because they grow quickly and can tolerate the cold. They survive our long winters by burrowing underground or under leaf litter that is then protected by an insulating layer of snow.
While most amphibians would freeze to death when the temperature drops below 0˚C, wood frogs can survive temperatures down to –12˚C. Their blood contains glucose that prevents the cells from bursting when they freeze, thus preserving their structure. When the temperature warms, the frogs thaw out and emerge from hibernation alive and well.
Quack like a frog
Even with ice still on the water, the male wood frogs start croaking, calling to find a mate. They breed in clear, shallow water across the Yukon, well before you would think a cold-blooded animal would be active. Wood frog eggs are laid in tennis-ball-sized globular masses attached to sticks or plants underwater. You can often see the eggs close to shore.
Frog-viewing tips
Wood frogs can be spotted at any time of year (except winter) in any wetland or moist forest. It’s not unusual to find them in your garden or on your front lawn. Put on some rubber boots and walk slowly around the edge of a pond. Watch for frogs jumping in front of you, and then follow where they go. Their camouflage is so effective you may only spot them when they move.
Rainy days are some of the best times to hit the trails. Like all amphibians, wood frogs need moisture, so you’re more likely to find them in the forest when it rains. Slowly paddling along the edge of a lake or pond is another great way to look for them.
If you do see a frog, try to take a picture of it rather than pick it up. Our hands contain oils and chemicals that can be harmful to the frog’s sensitive skin. Binoculars or a telephoto lens is a great way to get a closer look without disturbing them.In early May, the Yukon government’s Wildlife Viewing Program hosts a walk to a local pond, to listen and look for wood frogs. You’ll learn about the difference between frogs and toads, the importance of frogs in our ecosystem and what to listen for when you’re out exploring on your own. Check out Yukon.ca/wildlife-viewing for this year’s event details.
