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Mink Frog

Lithobates septentrionalis

What do they look like?

Adult length: 4.8 to 7.6 cm

Their backs are green, olive, or brown with irregular blotches. The dorsolateral folds are poorly developed or sometimes even absent in this species. Webbing extends to its fifth digit on its hind feet. Their undersides are whitish or yellowish. They have round spots or stripes on the upper parts of their hind legs. There is some sexual dimorphism. Male Mink frogs have larger tympanums than females. Males also often have a bright yellow throat compared to the white or pale yellow throat of the female. The tadpoles prior to metamorphosis have a dorsal coloration that is green, olive, or brown with scattered spots. Tadpoles also have a yellowish underside with a long pointy tail (Harding 1997).

Where do they live?

The Mink frog is found in Minnesota, Wisconsin, northern Michigan, and in northern New York. They are also found in Canada ranging from Quebec to the southeastern portions of Manitoba (Mossman et al 1999).

What kind of habitat do they need?

They enjoy permanent wetlands since they are primarily aquatic creatures, but they will move on the land if the conditions are damp and covered in heavy forest (Reptiles & Amphibians of Minnesota 1999).

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

How do they grow?

How do they reproduce?

Mink frogs do not begin to breed until late May and usually end in August. Males vocalize while floating on the water (Reptiles & Amphibians of Minnesota 1999). In the Great Lakes area the eggs are deposited in June and July. An average female will lay between 500 and 4,000 eggs in one cluster. The cluster may be laid up to a meter under the water and will eventually sink to the bottom before hatching. The tadpoles are in the larvae stage for about a year before metamorphosing into froglets. It takes the female about two years to become sexually mature whereas it takes the males only about a year to become mature (Harding 1997).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    730 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    547 days
    AnAge

How long do they live?

  • Range lifespan
    Status: wild
    6 (high) years
    AnAge

How do they behave?

Mink frogs are usually found where there are a lot of water lilies. They use these lilies as a way of protection from predators (Mossman et al 1999). The Mink frog produces an odor when handled.

What do they eat?

Mink frogs have a largely aquatic diet. They feed mainly on spiders, snails, dragonflies, whirligig, and beetles, all of which can be found on the surface of the water or on lily pads. Mink frog tadpoles feed mainly on algae (Harding 1997).

Are they endangered?

Reports have stated that Mink frog populations are declining, but they are not in serious trouble yet. The decline might be due to competition from the green frog, a larger, ubiquitous species (Harding 1997).

Contributors

Karri Kauzlarich (author), Michigan State University, James Harding (editor), Michigan State University.

References

Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. MI: The University of Michigan Press.

LeClerc, J. "Reptiles & Amphibians of Minnesota: Mink Frog" (On-line). Accessed November 17, 1999 at http://earthvision.asu.edu/~joe/Minnesota-Herpetology/frogs_toads/Mink_frog.html.

Mossman, M., J. Sauer, G. Gough, L. Hartman, R. Hay. 1998. "The Wisconsin Frog and Toad Survey home page" (On-line). Accessed November 17, 1999 at http://www.mbr-pwrc.usgs.gov/wifrog/from.htm.

Think Quest, "Mink Frogs" (On-line). Accessed November 17, 1999 at http://library.advanced.org/11034/index.htm.

 
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Kauzlarich, K. 2000. "Lithobates septentrionalis" (On-line), Animal Diversity Web. Accessed August 24, 2019 at http://www.biokids.umich.edu/accounts/Lithobates_septentrionalis/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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