Spring has arrived in Eberwhite Woods!

The wood frogs and spring peepers are out! The sounds of the spring peepers is deafening in the woods right now. There are also wood frogs calling (they sound like ducks). Here are three videos taken April 13th - one of mating wood frogs (it's called amplexus when they mate), one of a male spring peeper calling (check out his vocal sac expanding), and one of swimming wood frogs. Be sure to head into the woods to listen and look for the wood frogs out before they are gone - they have the shortest window of breeding time for any Michigan toad or frog (this is why they are known as explosive breeders).

Here is a little more information about wood frogs: Species Spotlight by Jenny Jacobs

Very soon, spring will come to our northern woods and ponds will come alive with frog songs. These early spring frogs seem to suddenly appear out of nowhere, which leads to the question, “where do these frogs go in the winter?”. While many amphibians and reptiles burrow deep down in the mud under ponds or on land below the frost line, a group of small forest frogs have a different way of surviving the winter – they freeze! This group includes common species one might find in Eberwhite Woods, like chorus frogs, spring peepers, gray treefrogs, and wood frogs. 

Wood frogs might just be the superheroes of this group, and the entire amphibian world, be-cause they can freeze up to 2/3 of their body water and survive in a “frozen” state for approxi-mately seven months in temperatures down to zero Fahrenheit! As temperatures start to drop with the onset of winter, wood frogs produce natural antifreeze, in the form of glucose, that they pump into their cells. They also begin to store urea (pee) that helps prevent too much ice from forming in their body. As the watery parts of their body begin to freeze, creating a hard, icy block, their individual cells remain unfrozen. And as the winter temperatures plunge, a wood frog’s heart eventually stops beating, the lungs stop working, and individual cells, though frozen, stop communicating with each other. They become frogsicles, and for all practical purposes, are dead. But they are alive... 

As soon as the temperature warms sufficiently, the frogs begin to thaw. Depending on where they live, a wood frog may thaw and leave hibernation from early March – mid May. Their hearts start beating even before their entire body has thawed. It takes about one day for a wood frog to thaw and one more day for them to migrate to a pond to breed. In parts of the wood frog’s range where winter temperatures fluctuate, like Eberwhite Woods, the frogs may go through various freezing and thawing cycles. However, they don’t completely leave the hibernating state until early spring. Wood frogs are considered “explosive breeders” because they migrate in masse to bodies of water to breed. Here, the males call females with a duck-like quacking sound. After breeding occurs, females lay egg masses in the water and tadpoles develop over a couple of months. New adult frogs eventually migrate away from the water and start their terrestrial lives, often returning to the same ponds year after year. 

Wood frogs are the only frog species able to live in extreme northern latitudes above the Arctic Circle. Wood frogs can be found in Alaska and across most of Canada and inhabit the northern Mid-west and northeast regions of the United States. They can be found in a variety of habitats within their range that include tundra, woodlands, bogs, wet meadows, and different types of forests. They require bodies of water, without fish, to reproduce. When they are not breeding, they migrate away from water and live under logs, and in leaf litter or low vegetation. 

References:: https://en.wikipedia.org/wiki/Wood_frog 

http://www.biokids.umich.edu/critters/Lithobates_sylvaticus/ 

https://owlcation.com/stem/Frozen-Wood-Frogs-and-Adaptations-for-Survival 

https://www.a2gov.org/departments/Parks-Recreation/NAP/Pages/Natural-Area-Preservation-News-Winter-2017.aspx#frogsinwinter