Wood frog – Rana sylvatica
It’s a beautiful late winter day and the hills are alive with the sound of, well—hoarse ducks? If your late winter sojourns take you into wet areas, keep your ears open for the croaking or “quacking” of wood frogs, Rana sylvatica. These small woodland frogs are generally the first amphibians to breed in the Southern Appalachians—egg masses may be found as early as February.
The wood frog is three to four inches long and ranges in color from a coppery green to dark brown. They have two prominent ridges along their back and a black Lone Ranger mask covers the eye. They live in primarily forested habitat and converge at intermittent vernal pools and/or any low-lying area that will likely hold water for a couple of months to mate and deposit eggs before retreating back to their brushy refuge.
Wood frog facts
Wood frogs are the only North American frog found north of the Arctic Circle. They are the most widely distributed amphibians in North America found from the Appalachian mountains of North Georgia to northern Canada, western Alaska to the Upper Midwest of the U.S.
They make the perfect cryonics poster child. While other frogs hibernate by burrowing below the frost line, wood frogs simply crawl beneath the leaf litter. You can imagine what that means when it’s -30° F in northern Canada — yep, frog popsicle. These amazing creatures can freeze solid; up to 65-percent of their body-water can turn to ice, blood does not circulate and their heartbeat and breathing cease. When temperatures rise above freezing they thaw out, none the worse for wear.
Wood frogs can utilize vernal pools because the eggs can metamorphose from egg to tadpole to frog in as little as 45 days.
Frogs evolved during the Devonian Period, more than 300 million years ago. Fossils of frogs as we know them today date back 190 million years.
And one more cool thing — should you chance upon a vernal pool filled with tadpoles, pay attention as you approach. Scientists believe wood frog siblings can recognize each other and the tadpoles will clump together in familial groups.