Amphibian Breeding / Hydroperiod
Frogs, toads and salamanders reproduce at different times from late March to June, depending on the species. Early breeders (such as spring peepers, wood frogs, chorus frogs, salamanders) typically reproduce in shallow, seasonal wetlands. Green frogs and mink frogs reproduce in larger more permanent wetlands.
For breeding to be successful, the wetland must remain inundated long enough for the larval stages to metamorphose into adults. This period varies depending on the species, but a rough guide is that the wetland should remain inundated at least through June 1 in southern Minnesota. This period of inundation will not accommodate all species, but is reasonably likely to ensure that the wetland is suitable for breeding by some amphibians.
Optimal amphibian breeding habitat is characterized by a lack of predatory fish. These habitats are wetlands that winterkill, dry periodically, are periodically anoxic, and are not connected to waters bearing predatory fish. The wetland should not be used to rear bait or game fish.
Wetlands that are deep and well oxygenated provide over-wintering habitat for leopard, green and mink frogs, as well as turtles. Evidence of over-wintering would be observations of migrations of frogs to the wetland in fall and away from the wetland in spring and basking turtles in the spring.
Source: Minnesota Routine Assessment Method (MnRAM), Version 3.4, Minnesota Board of Water and Soil Resources