Frogs and Toads Surviving the Winter
Frogs and toads create winter homes called hibernaculums. While in their retreats, their metabolisms slow down to the bare minimum so they can survive the winter with stored energy only. There are three main strategies that frogs and toads use to survive freezing winter temperatures:
- An Underground Shelter – Around here the ground temperature below the frost line is a toasty 55 to 60 degrees. All the toads and a few frogs spend the winter in an underground burrow where there is no chance that they will freeze. Their bodily functions slow down considerably, but don’t stop. Frogs that use this strategy include the Crawfish Frog.
- A Watery Deep Sleep – Did you know that water density increases as it gets colder – that is, down to a point. The most dense water occurs at about 39 degrees fahrenheit. Colder than that water becomes less dense. So during the winter, the water at the bottom of a pond will be no colder than 39 degrees because the less dense, colder water will not sink as low. That bottom water is just right for a long winter nap for the aquatic frogs – Bullfrog, Leopard Frog, Pickerel Frog, and Green Frog. They lay on the bottom (not under the mud) in a state of torpor and absorb oxygen through their skin from the water.
- Roughing it Topside – Frogs can get out of the wind, but can’t avoid the cold if they stay topside during the winter. All the tree frogs find crevices in rocks and tree trunks and under leaf piles to stay protected. They are particularly cold-hardy by shutting down almost completely. If you found one of them during the winter, you would think they were dead. Spring Peepers create a kind of internal “anti-freeze” that keeps them from freezing. Wood Frogs do the same thing and are the only frogs that can survive north of the Arctic Circle.
What can you do to help frogs and toads in the winter?
- During your Fall yard cleanup, leave a few leaf piles in the corners. They will not only help over-wintering tree frogs, but lots of other creatures will also appreciate it.
- If you have a pond on your property or intend to build one, try to make it deep enough so that it doesn’t freeze solid during the winter (18″ or more in the middle).
- Do a search online for toad houses, abodes, or hibernaculums. It can be as simple as a two-foot long piece of 4″ plastic pipe sunk into the ground on a 30 degree angle and filled with sand and composted leaves. The opening should be about 1/2 exposed.