Rana septentrionalis
mink frog

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).

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).

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).

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.

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).

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).