Despite inhabiting northern areas, the mink frog cannot survive freezing temperatures, and so escapes the cold by spending the winter hibernating underwater in the bottom mud (1) (3) (4) (9). It usually enters hibernation by late September, and remains inactive until May (3).
After emerging from hibernation, the male mink frog begins calling from the water to attract a mate, either alone or in a group chorus (3) (4). The breeding season runs from late May or June to early August (3) (4) (5) (9), and most breeding activity occurs at night (10). The female mink frog lays a globular mass of 500 to 4,000 brownish eggs, which are attached to submerged plant stems. The eggs may be laid at depths of a metre or more (3) (4) (9), helping to protect them if the surface water freezes, and the egg mass may sometimes sink to the bottom before the eggs hatch (3) (9).
The length of time needed for the mink frog’s eggs to hatch is not well known (9), but once hatched the tadpoles normally take a year to fully develop, with metamorphosis occurring the following July or August (9) (10) (11), when the tadpoles are about 2.5 to 4.2 centimetres long (9) (11). However, some mink frog tadpoles take two years to metamorphose, and may grow to a larger size before transforming into the adult (3) (4) (9) (11). Northern populations in particular may have a longer tadpole stage and metamorphose at a larger size (6) (9).
The adult mink frog reaches sexual maturity around one to two years after metamorphosis, with the female tending to mature later and at a slightly larger size than the male (3) (9) (10). Individuals in northern populations mature later than those in the south (6) (9). Most mink frogs only live for between one and four years after metamorphosis, but some survive for up to five or six years (9).
The tadpole of this species feeds on algae (3) (9) (12), but the adult mink frog is an opportunistic predator and eats a range of insects and other small animals, including dragonflies, beetles, aphids, spiders, snails and even small fish (3) (4) (9) (12) (13). The diet may vary depending on the available prey, and most food is taken at the water surface, with the mink frog typically sitting on floating vegetation and waiting for prey to come close (3) (9) (12). Although the mink frog has been found to eat some plant material, this is thought to be ingested accidentally when prey is captured (9) (12) (13).
The mink frog and its tadpoles may be predated by American bullfrogs (Lithobates catesbeianus) and other amphibians, as well as by raccoons, herons, snakes and fish. However, its musky skin secretions are likely to discourage some predators (3) (4) (9). When threatened, the mink frog usually dives into the water and hides in mud or vegetation (3) (9).