Winter weather has arrived in most parts of Michigan by now, bringing dread for some, and excitement for others. But have you ever wondered what’s happening under the snow? Many of Michigan’s reptiles and amphibians search for tunnels or other underground cavities to wait out the cold winter temperatures. Still others might remain underwater, remarkably surviving the long winter months with little to no oxygen!
Such is the case with the Green Frog (Lithobates clamitans), one of Michigan’s most abundant frog species. These semi-aquatic amphibians spend their winters hibernating at the bottom of permanent pools and rivers, “breathing” in oxygen through their skin, occasionally nestled among piles of leaf litter that give off some amount of heat as they decompose, and sometimes can be seen swimming before the water has frozen over, or through clear ice. *A common misconception of hibernating animals is that they spend the entire time ‘sleeping’, when in fact hibernation is rather a period of reduced activity.
So, why spend the winter underwater rather than on land? Other frogs in Michigan like the wood frog, spring peeper, as well as toads, hibernate in tunnels and under leaf piles. These frogs are able to survive the freezing temperatures because they produce excess glucose which helps prevent freezing of the cells in their bodies, acting as a sort of antifreeze. Green frogs on the other hand, are not able to function in this way, and so they must stay in above-freezing temperatures through the winter.
Adequate winter habitat for these species is a critical part of ensuring their survival to the next season, and threats to that habitat exist – even as the snow flies! For many of us, fall is a time for “cleaning up”, for raking up all the leaves that have fallen (and jumping in the pile), then bagging them up and shipping them off to a community dump site. But this practice robs our yards and natural areas of needed habitat, not only for the insects that overwinter in leaf piles like caterpillars and firefly larvae, but also for the many reptiles and amphibians that call our state home. The leaves provide a “blanket” between the ground and the snow, they provide heat as they decompose in place which also returns essential nutrients to the soil.
There are so many benefits for Michigan nature from leaving the leaves, so skip the fall “cleanup” and enjoy reap the rewards come springtime. Learn more about Michigan’s many reptiles and amphibians, and their conservation needs, with Herpetological Resource & Management at herprman.com, and learn more about the benefits of leaving leaves, visit healthyyards.org or leaveleavesalone.org
Michigan Nature Association 