wood frog

(Rana sylvatica)

Conservation Status

IUCN Red List

LC - Least Concern

wood frog


N5 - Secure

S5 - Secure


not listed




Moist wooded areas, ponds in woods and prairies.


3 to 4 years


1¼ to 2

Photo by Kirk Nelson


This is an easily recognized, medium-sized, terrestrial frog. It is 1½ to 3¼ long at maturity. Females are much larger than males.

The back (dorsal surface) is smooth to moderately rough. Prominent folds on each side of the back (dorsolateral) extend from the head to near the vent. The folds are light on top, dark on the sides. There are often additional short folds on the back between the dorsolateral folds.

The color varies. It is usually tan or brown, sometimes gray, reddish-brown, or yellowish-green. Females are usually more reddish than males. The back and sides may have dark mottling.

The belly (venter) is white, yellowish-white, or greenish-white and often has dark mottling on the throat and breast. There is a prominent dark mark on each side of the chest near the forelegs (pectoral region).

A prominent dark face mask extends from the snout to just behind the ear covering (tympanum). The tympanum is smaller than the eye. The upper lip is white.

The back legs have horizontal bands that may be dark or faint. The feet are webbed. On the fourth toe two or three joints are free of the webbing. Males have larger “thumbs” and stouter forelegs.


A short croak repeated several times. Often compared to the quacking of a duck.


The prominent dark face mask, often referred to as a robber’s mask, on a brown frog is a unique identifying characteristic. No other species is similar in overall appearance.

Tadpole Food

Algae, decaying organic matter, eggs and embryos of some salamanders

Adult Food

Spiders, beetles, bugs, moth larvae, slugs, snails, and other insects and small invertebrates.

Life Cycle

Breeding is explosive. It occurs from late March to late April after the first warm spring rains, often before ice is completely off the pond. Males do not defend territories at this time but frantically swim after and grab other individuals hoping to find a receptive female.

After breeding, the female will deposit 300 to 1,000 eggs in a mass (clutch) loosely attached to emergent vegetation usually near the clutches of other females. Communal egg laying is thought to raise the temperature of the of the communal mass promoting faster development and to protect the inner eggs from leeches and other predators. Metamorphosis occurs at 65 to 130 days. The tadpole is 2¾ to 2 long preceding metamorphosis.

Adults overwinter under the shelter of a log, rock, bark, or leaf litter. They are freeze tolerant and can survive multiple freeze-thaw cycles. Glycerine is produced preventing the formation of ice crystals in vital organs.

Males typically live 3 years, females 4 years.


Wood frogs are territorial. Territory size is usually about 100 square meters.

Summer months are spent in moist woods or wooded swamps, bogs or ravines. In late fall the frogs migrate to nearby upland areas to find a site to overwinter.

Distribution Distribution Map   Sources: 7, 11, 12, 13, 14, 24, 29, 73.


In 2006 most North American true frogs were transferred from the genus Rana to the genus Lithobates by Frost et al. The change was controversial and was not accepted by all authorities. In 2008 and 2009 the change was rejected by Stuart, Pauly et al., and other systematic reviews, and in 2009 North American true frogs were returned to their previous classification. Lithobates is once again a subgenus of Rana. ITIS37 and Amphibian Species of the World61 continue to use the 2006-08 classification. NCBI34 and UniProt33 use the new classification. AmphibiaWeb60 suggests using the original name followed by the subgenus name in parentheses. In this case, Rana sylvatica, the species is not classified into a subgenus.



Batrachia (amphibians)



Anura (frogs and toads)









Ranidae (true frogs)


Lithobates sylvaticus

Rana cantabrigensis

Rana cantabridgensis latiremis

Rana cantabrigensis evittata

Rana maslini

Rana sylvatica sylvatica

Rana sylvatica cantabrigensis


wood frog









The circular, disk-like membrane that covers the ear opening of some reptiles and amphibians.























Visitor Photos

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Kirk Nelson

  wood frog   wood frog

Dan W. Andree

Wood Frog...

Taken in the woods near a creek on a trail near Twin Valley, Mn. in Norman county on 5-26-19..neat frogs they are...

  wood frog    


  wood frog   wood frog

Jill H.

This frog has been helping with my landscaping and is happy we are done.

  wood frog    

Laurie Grimm

  wood frog    

Bill Reynolds

  wood frog    


MinnesotaSeasons.com Photos

  wood frog   wood frog
  wood frog    





  Wood Frog
Andree Reno Sanborn
  Wood Frog  

Rana sylvatica

  Wood Frog (Lithobates sylvaticus)
Bill Keim
  Wood Frog (Lithobates sylvaticus)  
  Rana sylvatica (Wood Frog)
Allen Chartier
  Rana sylvatica (Wood Frog)  
  Wood Frog
Nick Scobel
  Wood Frog  
  Wood Frog (Rana sylvatica)

Published on Apr 30, 2012

No description available.





Visitor Videos

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Other Videos

  Time-lapse video of a wood frog (Rana sylvatica) thawing.
The Company of Biologists

Published on Jun 26, 2013

Time-lapse video of a wood frog (Rana sylvatica) thawing at 4°C following an experimental freezing exposure to --2°C for 24 h.

The original Commentary paper is available at http://jeb.biologists.org/content/216/11/1961.abstract

  Mating Wood Frogs, Rana sylvatica

Uploaded on Apr 11, 2009

A collection of short video clips of calling and mating wood frogs (Rana sylvatica). Videos taken the first few days of April, 2009, on the University of Michigan's E.S. George Reserve.





Visitor Sightings

Report a sighting of this amphibian.

Kirk Nelson

Location: Lebanon Hills Regional Park, near the stream that flows into Schulze Lake

wood frog

Dan W. Andree

Location: near Twin Valley, Mn. in Norman county

Taken in the woods near a creek on a trail ... neat frogs they are...

wood frog


Location: Mound, MN

wood frog

Jill H.

Location: Vadnais Heights, MN

This frog has been helping with my landscaping and is happy we are done.

wood frog

Laurie Grimm

Location: Hemlock Ravine SNA

wood frog

Bill Reynolds

Location: Pennington Co Mn

wood frog


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