Wisconsin Sea Grant: Frog Field Guide

Mink Frog
(Rana septentrionalis)

Call: A series of soft, low-pitched croaks, similar to the sound of distant hammering ("tok, tok, tok, tok")

Size: 4.8-7.6 cm in length (1.8-3 inches)

Coloring:
Green, olive or brown with darker spots all over; undersides are whitish or yellow

Habitat:
This "north woods" frog species is found only in the northern Great Lakes region and likes streams, ponds, lakes where there are cool, permanent bodies of water with lots of lily pads and other water plants. They are found only in northern Wisconsin, northern Ontario, Canada, and Michigan's Upper Peninsula.

The Mink Frog likes hanging out on lily pads or clumps of floating weeds, where it hunts for meals of aquatic insects or other small invertebrates.

Confusing Species:
Young Bullfrogs tend to be green with only a few spots; Green Frogs look very similar to Mink Frogs, but Green Frogs have crossband markings on the hind legs and lack the musky odor of Mink Frogs.

Breeding: Late May-early August

Did you know?

Perhaps what makes the Mink Frog most unique is its smell. When handled, this frog will give off a musky odor said to resemble the smell of a mink. If you don't know what a mink smells like, other people have compared this frog's smell to rotting onions!

copyright 2001 University of Wisconsin Sea Grant Institute