Wood Frog
Photo: Brian Gratwicke
Wood frogs are easily identified by their loud duck-like quacking calls, the “white lipstick” line above their lips, and the dark “mask” across their eyes. Body color can vary between shades of brown, rust, gray, tan, and green, the tones of which provide camouflage in their woodland habitat. Wood frogs are about 2 ½ -3“ long, with the females being generally larger and lighter in color. The adults eat insects and small invertebrates, while the larvae eat algae and larvae of other amphibians.
During the winter, wood frogs hibernate under the leaf litter of the forest floor. They can literally freeze 65% of their body, becoming virtual frogsicles.
Wood frogs are one of our earliest frogs to breed in the spring. Stimulated by warm rains, they climb out of their frozen torpor and make their way to a nearby vernal pool. The males arrive first and sing to attract the females, creating a cacophony that sounds like a chorus of diminutive ducks. Once the females arrive, the breeding event has been described as “explosive”, with males frantically “hugging” other frogs to discern whether it’s a female (they can’t tell by sight or smell). The females lay up to 1000 eggs, which look like masses of tapioca suspended in the pool. Adults return to the same pool to breed during their 3-5 year lifespan; but the young often disperse in search of new pools.
Wood frogs are one of four indicator species for the designation of Maine’s significant significant vernal pools. If a pool has more than 40 wood frog egg masses, then it warrants protection under the Natural Resources Protection Act.
So keep your ears out next spring: if you think you’re hearing a misplaced flock of ducks in the woods, it’s more likely a frenzy of male wood frogs trying to call in some mates.