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Mink frog © Scott Gillingwater

This frog has a pungent, musky odour, like that of a mink.


The mink frog (Lithobates septentrionalis) is medium sized, olive to brown in colour and may have dark spots or mottling on the sides and hind legs, which have no dark bands. The belly is yellowish and the dorsolateral folds (folds of skin running down each side of the back) may be prominent, partial or absent. This species has large tympani (eardrums) and slightly upturned eyes. The webbing on the hind feet reaches the last joint of the longest toe. Adult mink frogs can reach seven centimetres in length. The call of this species consists of a rapid series of three or more croaks, which sound like the tapping of a metal hammer on wood. A large chorus of mink frogs sounds like popcorn popping. Listen to the call of the mink frog (courtesy of Adopt-A-Pond Wetland Conservation Programme).

Mink frog © John Urquhart

Similar Species

The green frog is nearly identical in appearance to the mink frog, and both species exhibit substantial variation in colour. The green frog has a white belly with darker lines or spots and occasionally a yellowish tinge, and dark banding on the hind limbs. It is important that observations of mink frogs submitted to the Herps of Ontario iNaturalist project include photographs to help in verifying identification. If possible, photographs should show the whole body and hind legs.

Mink frog © Jason King


Mink frogs are highly aquatic and rarely found on land. They inhabit large, cold, permanent ponds, lakes and slow-moving rivers with abundant vegetation, as well as sphagnum bogs. The eggs and tadpoles develop in permanent lakes and ponds. Both tadpoles and adults hibernate underwater.

View an interactive map of the known ranges of mink frogs in Ontario.


Mink frogs breed from late spring through midsummer. Choruses increase in intensity through the night and peak before dawn. The female deposits a globular mass of 500 to 2,000 eggs, usually attached to submerged vegetation up to a metre below the surface. The tadpole stage lasts one to two years and, after transforming into frogs, individuals reach sexual maturity in another year or two. Mink frogs may live up to six years.

Mink frogs eat various small invertebrates obtained mostly among aquatic plants in open water. The adults seem to be more skittish than adult green frogs and bullfrogs.

Other names: Rana septentrionalis

Mink frog © Peter Ferguson

Threats and Trends

Mink frogs, like many fauna, are threatened by habitat loss and degradation. The highly aquatic nature of this species probably means that it is less at risk of being killed on roads than more migratory species. Mink frog populations are believed to be stable, but little data is available to support this assumption. Data on the current distribution of mink frogs in northern Ontario is also lacking.

Mink frog © Scott Gillingwater

Current Status and Protection

Neither the Committee on the Status of Species at Risk in Ontario nor the Committee on the Status of Endangered Wildlife in Canada has assessed the status of the mink frog. The species has no protection under the Ontario Fish and Wildlife Conservation Act. The International Union for Conservation of Nature lists the global status of the mink frog as Least Concern. The species’ status was confirmed in December 2020.

Learn more about reptile and amphibian conservation and what you can do to help these species on our Reptile and Amphibian Stewardship page.

Mink frog © Ken Morrison

What You Can Do

  • Report a sighting
  • Get involved in reptile and amphibian conservation on your property, on the road and in your community
  • Donate to support reptile and amphibian conservation
  • Watch for reptiles and amphibians on the road
  • Don’t release pet reptiles and amphibians into the wild
  • Read more about the mink frog in the Ontario Reptile and Amphibians Atlas publication.
Mink frog © David Seburn