Rana sylvatica
Wood Frog
family: Ranidae
Taxonomic Notes: This species is placed in Lithobates by some authors, following Frost et al., 2006. This has been a controversial decision, because such well-known species as Rana catesbeiana, with an enormous literature, are made more obscure to many. What is not controversial is that Lithobates is the sister taxon of Rana, so the argument is simply one of Linnean ranks. AmphibiaWeb recommends treating Lithobates as a subgenus of Rana, with species names to be written as Rana (Lithobates) catesbeiana, as an example. This option preserves the maximal amount of phylogenetic information and preserves a long-standing taxonomy.

© 2010 Todd Pierson (1 of 86)

View distribution map using BerkeleyMapper.

Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
See IUCN account.
NatureServe Status Use NatureServe Explorer to see status.
Other International Status None
National Status None
Regional Status None


Adults are 37 to 83 mm in length, and females are larger. Prominent dorsolateral folds extend from the bead to near the vent. The lateral edge of each fold is darker than the medial edge. The smooth to moderately rough back often has short folds between the dorsolateral folds. Toes are webbed, with tow or three phalanges of the fourth toe free of the web. Dorsal coloring may be gray to tan to vivid reddish brown , and is coppery or golden in some individuals. Females are usually more reddish. Black or dark brown markings may be present on the back and sides, and many northern and western specimens have a middorsal white line. A conspicuous dark brown or blackish mask extends from the snout to just behind the tympanum. The white venter is sometimes darkly mottled on the throat and breast, and is smooth except for a granular region under the thighs. There also is a prominint dark marking in the pectoral region. The tympanum is smaller than the eye. Males have paired vocal sacs, stout forelegs, and a "thumb" and enlarged webbing between the toes during the breeding season.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Canada, United States

U.S. state distribution from AmphibiaWeb's database: Alaska, Alabama, Arkansas, Colorado, Connecticut, District of Columbia, Delaware, Georgia, Idaho, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Montana, North Carolina, North Dakota, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Virginia, Vermont, Wisconsin, West Virginia, Wyoming

Canadian province distribution from AmphibiaWeb's database: Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Northwest Territories, Nunavut, Ontario, Prince Edward Island, Quebec, Saskatchewan, Yukon

View distribution map using BerkeleyMapper.
R. sylvatica is the only cold-blooded tetrapod known to occur north of the Artic Circle in the Western Hemisphere. It is found over most of Alaska and Canada and over the northeastern part of the United States. Its northern limit lies along the treeline from Alaska to Labrador. Its range extends southward coastally to Maryland and in the Appalachian Mountains to northern Georgia and northeastern Tennessee. The southern edge of the range passes northward through southern Illinois and the norteastern corner of South Dakota, the noreastern half of North Dakota, northern Idoah and westward in Canada to near the Pacific coast. Isolated populations are found in souteastern Wyoming and northern Colorado, in eastern Kansas, in the Ozark Mountains of Arkansas and Missouri, and perhaps in areas north of the Artic tree line.
It is a terrestrial species, often found in or near moist wooded areas, sometimes considerable distances from open water.


Martof, B. S. (1963). ''Rana sylvatica (Le Conte). Wood Frog.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 86.1-86.4.

Written by Franziska Sandmeier (franturtle AT, UC Berkeley
First submitted 2001-02-21
Edited by Arie van der Meijden (28/2/2001) (2001-06-04)

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Citation: AmphibiaWeb: Information on amphibian biology and conservation. [web application]. 2016. Berkeley, California: AmphibiaWeb. Available: (Accessed: May 26, 2016).

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