Wisconsin Sea Grant Frogs: Field Guide

Wood Frog
(Rana sylvatica)

Call: A series of clucking croaks that resembles a quacking duck.

Size: 3.5-8.3 cm in length (1.4-3.3 inches)

Grayish brown, tan or bronze, with a dark "mask" extending from the eye through the shoulder region, and a white line along the upper lip; possible dark stripes on the hind legs.

Moist wooded habitats throughout the Great Lakes region.

Confusing Species:
The Striped Chorus Frog also has a brown mask-like patch on its face, but is smaller and lacks dorsolateral folds.

Breeding: Late March-April

FACT: In the winter, while many frogs hibernate in the mud at the bottom of lakes or ponds, the Wood Frog will hibernate on land beneath loose soil, leaves or decaying logs. They survive freezing temperatures by producing a natural "antifreeze" in their bodies.

Did you know?

This species gets its name because adults are rarely found in the water, instead preferring to live in the woods. They will venture out to watery areas only to breed, then they'll return to wooded areas. This habit presents a problem if a road is located between these frogs' forested homes and their breeding ponds.

Each spring, large numbers of adult Wood Frogs can be killed by automobiles while the frogs are crossing roads to get to and from their breeding grounds.



copyright 2001 University of Wisconsin Sea Grant Institute


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