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Upper Midwest Environmental Sciences Center

Farm ponds as critical habitats for native amphibians
A Field Guide to Amphibian Larvae and Eggs of Minnesota, Wisconsin, and Iowa
Field guide contents

Wood Frog Rana sylvatica

Status: Wisconsin – Common
Minnesota – Common
Wood Frog
4.2 - 4.8 cm total length

field mapAdult Wood Frogs have the same general shape as other members of their genus—but are brown instead of green—with a dark brown eye mask. They breed early in spring and their eggs are often the first ranid eggs laid in the year. The eggs (500–3,000) are laid in loose, round globular masses (5–12 cm diameter) attached to submerged vegetation, often near the surface. Many females lay their eggs in the same vicinity. Egg masses are rather flimsy (although less flimsy than Northern Leopard Frog egg masses) and lose their shape when lifted from the water. A large amount of clear jelly in the egg mass causes the eggs to be widely separated. Larval Wood Frogs have clear tail fins that end in a sharp point. The fins are higher than other ranid tadpoles. The musculature of the body and tail is colored uniformly brownish with a greenish sheen. The belly is usually cream-colored with a cream line along the edge of the mouth.

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Page Last Modified: December 29, 2010