About Lithobates septentrionalis (Baird, 1854)
This species, commonly known as the mink frog, has the scientific name Lithobates septentrionalis (Baird, 1854). Adult mink frogs are small, reaching a length of 4.8 to 7.6 cm (1.9 to 3.0 in). Their back (dorsum) is typically green, marked with darker green and brown blotches, while their belly is cream, yellow, or white. Mink frogs display clear sexual dimorphism: males usually have a bright yellow throat, while females have a white throat. Male mink frogs have a tympanum (eardrum) larger than the eye, while the female tympanum is smaller than the eye or equal in size to it. All mink frogs have a pale underside and bright green lips. Mink frogs are distributed across North America: in the United States, they can be found in Minnesota, New Hampshire, Wisconsin, Michigan, Maine, Vermont, and New York. In Canada, they occur in Nova Scotia, New Brunswick, Newfoundland and Labrador, Quebec, Ontario, and Manitoba. This is a largely aquatic frog species whose entire southern range limit sits at the highest latitude of any North American frog. Evidence indicates that more southern populations of this frog have gone extinct within the past century. The mink frog is predominantly aquatic, living among vegetation (especially lily pads) in ponds, swamps, and wooded-area streams. It feeds on a wide variety of prey including spiders, snails, beetles, and other invertebrates. Mink frog tadpoles feed primarily on algae and decaying plant matter. Mating for mink frogs typically occurs in late spring and early summer. They prefer cold, well-oxygenated wetland breeding sites. At these sites, during late night hours (and occasionally during the day), males call to attract females while floating on the water surface or resting partially on floating vegetation. A single female can lay between 500 and 4000 eggs at a time, usually in deep water. Egg masses are typically found close to floating vegetation and hatch within just a few days after being laid. Tadpoles stay in the larval stage for approximately one year before undergoing metamorphosis into froglets. Male mink frogs reach maturity one year after metamorphosis, while females reach maturity in two years.
