Wood Frog

Description

A wood frog’s most distinct characteristic is the black marking across its eyes, which has been said to resemble a mask. The bodies of wood frogs can be varying shades of brown, red, green, or gray, with females tending to be more brightly colored than males. Adults of this amphibian species are 1.5 to 3.25 inches (3.8 to 8.2 centimeters) in length.

These frogs have adapted to cold climates by freezing over the winter. During this time, they stop breathing and their hearts stop beating. Their bodies produce a special antifreeze substance that prevents ice from freezing within their cells, which would be deadly. Ice does form, however, in the spaces between the cells. When the weather warms, the frogs thaw and begin feeding and mating again.

Range

Wood frogs are found in the United States throughout the forests of Alaska and the Northeast. They are found in smaller numbers as far south as Alabama and northwest into Idaho. Wood frogs are the only frogs that live north of the Arctic Circle. Adults usually live in woodlands and lay eggs in vernal pools. During winter, they take shelter in leaf litter. A variety of snakes eat adult wood frogs. The frogs also fall prey to snapping turtles, raccoons, skunks, coyotes, foxes, and birds. Tadpoles face a different set of predators, including beetles, salamanders, wood turtles, and other wood frogs.

Diet

Adults use their long, sticky tongues to catch insects, arachnids, worms, slugs, and snails. Tadpoles are mostly herbivorous and eat algae and decaying plant matter, though they have also been recorded eating eggs or larvae of other amphibians.

Life History

Wood frogs are one of the first frogs to begin the breeding season, usually in early March. During the breeding season, males can be heard making quack-like calls day and night. Females lay masses of 1,000 to 3,000 eggs, which hatch between 9 and 30 days later. Maturity may be reached in one to two years, depending on the sex and the population of frogs. A wood frog’s lifespan in the wild is usually no more than three years.

Conservation

The wood frog’s population is stable, but habitat loss due to farming and development may affect them in some areas.

Fun Fact

In the amphibian world, wood frogs may be the species best able to recognize their family. When many tadpoles are in the same place, siblings seek each other out and group together.

Sources

Animal Diversity Web, University of Michigan Museum of Zoology

eNature.com

Minnesota Department of Natural Resources

NatureServe Explorer

Virginia Herpetological Society