In you hear an odd “knocking” sound on summer nights—a little like a hammer striking a piece of wood—it could be a male mink frog, staking out territory and calling to its potential mates. Mink frogs have a long, leisurely breeding period, beginning in June and lasting well into August. (The frogs hibernate during the winter, but, in Canada, are active as early as April and as late as October.)
The mink frog gets its name for stinky reasons. When predators (or people) touch it, it releases a foul, musky stench that smells a little like rotting onions. (Minks—the mammals—also use their stink in defense; they send out a liquid that reeks almost as badly as skunk spray.) But because mink frogs are almost entirely aquatic, most cottagers won’t have as many opportunities to spot them, never mind pick them up. Mink frogs require water—wetlands, ponds, slow-moving rivers—for breeding. They also hibernate in the water; adults dig into the soft bottoms of water bodies and hunker down, covered for the cold season.
The wood frog can survive winter by freezing solid!
The mink frog is easy to confuse with another North American species, the green frog. But the former is smaller (on average, five to seven centimetres long instead of six to nine) and has dark spots or blotches, not bands, on its hind legs. (Also, only the mink frog stinks.)
One female mink frog can lay up to 4,000 eggs in one clutch, attached to submerged vegetation. Even though the eggs hatch in a couple of weeks, mink frogs spend up to two years as tadpoles before developing into wee, inch-long froglets. An adult frog can live up to six years after metamorphosis. Because they spend so much time in the water—especially cold, northern water—mink frogs happily don’t have to deal with some of the threats that harm other amphibians.