Michigan’s Winter Wonders: Green Frog

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.

a green frog sits on a rock in the water
A green frog rests on a rock at MNA’s Joan Rodman Memorial Nature Sanctuary. Photo by Jodi Louth.

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

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A Milestone Year

The Michigan Nature Association is celebrating its 70th Anniversary throughout 2022. MNA’s spirited founding generation pioneered the protection of critical habitat for rare, threatened and endangered species, establishing Michigan’s oldest land conservancy and the only one
that serves the entire state. They also laid the foundation for our remarkable sanctuary network, and thanks to supporters past and present, it now includes over 180 sanctuaries in 60 counties. For some plants and animals MNA protects the finest—and sometimes the only—remaining habitat. We protect Michigan nature, we protect it for everyone, and we strive to protect it forever.

Join the celebration by learning more about some of our historical milestones below, and watching our 70th Anniversary video!

Image showing timeline of events in Michigan Nature Association history.
Top to bottom: What started as a bird watching group in 1951 signs articles of incorporation in 1952. In the 1960s, the organization acquires its first 10 properties, including its first Upper Peninsula property. In the 1970s, MNA joins the “Save the Pines” campaign and acquires one of its crown jewels: the Estivant Pines Nature Sanctuary. In the 1980s, Twin Waterfalls Memorial Plant Preserve becomes the 100th property protected by MNA. In the 1990s, MNA creates nearly 40 new nature sanctuaries that will become the most frequently visited. In the 2000s, MNA partners with the Michigan Karst Conservancy to protect the Mystery Valley Karst Preserve and Nature Sanctuary. In the 2010s, MNA is awarded accreditation by the Land Trust Accreditation Commission, and earned its first renewal in 2019. In the 2020s, MNA joins the “Keep the U.P. Wild” Coalition, seeking wilderness designation for more than 40,000 acres of land in the Upper Peninsula. Today, MNA celebrates 70 years of protecting Michigan’s natural heritage.

Celebrating Michigan’s Wilderness on World Rewilding Day

Today, March 20th, Michiganders across the state are celebrating the start of spring. We, too, look forward to all that this season brings including wildflowers, bird migration, and more. But today, we are especially excited about World Rewilding Day—established in 2021, World Rewilding Day raises awareness of the need for large, ‘wild’ habitat in the fight against climate change-driven extinctions.

An aerial photograph showing the Ottawa National Forest. Photo by Jason Whalen | Fauna Creative

Our recently-released video “Keep the U.P. Wild” explores one such effort in Michigan’s Upper Peninsula. The Keep the U.P. Wild Coalition last year began a campaign to add federal Wilderness designation to more than 40,000 acres of land in the western U.P., and has since grown to include more than 300 organizations.

Designation requires congressional action, which would provide the highest level of federal land protection for the four areas within the one-million-acre Ottawa National Forest in the western Upper Peninsula: The Trap Hills, Ehlco Area, Norwich Plains, and Sturgeon River Gorge Wilderness Addition.

If successful, wilderness designation would protect these areas for biological diversity, not resource extraction, while still providing opportunities for their respectful use, enjoyment, and economic benefit.

 “The scientific community has learned … that connections and scale really play an important role in the ability of many species to exist over time,” said MNA Conservation Director, Andrew Bacon. Wilderness designation at this scale would most certainly benefit the flora and fauna and provide for the natural processes that help reduce the effects of carbon in the atmosphere—one of the leading drivers of climate change.

Watch our video today, and learn more about this campaign and the coalition members at keeptheupwild.com.

Michigan’s Landscape Architects – Beavers

The Michigan Nature Association prides itself on protecting habitat for many different species, through the conservation and stewardship at our more than 180 Nature Sanctuaries. But there are times when the needs of one species are counterproductive to the needs of another.

Historically, the American beaver was hunted—nearly to extinction—by fur trading Europeans. Their resurgence across the Midwest has been thanks to conservation efforts, not only for them but also for other species as well.

A beaver swims through a pond. Photo by Lauren Ross.

Beavers are incredible builders, able to construct lodges up to 8 feet wide and 3 feet high, using only their teeth to cut branches and logs, which must then be transported over land and water to the construction site. They are also incredibly effective dam builders—significantly affecting the flow of rivers and streams, which can then flood hundreds of acres of land, creating the ponds and lakes that they require for survival. 

Beaver dam at an MNA Nature Sanctuary. Photo by Andrew Bacon.

This keystone species are the architects of wetlands and pools in riparian ecosystems—the area between land and rivers and streams. Their damming and wetland creation is invaluable for a wide diversity of wetland birds, herptiles, and insects. Where beavers are allowed to operate in their natural capacity, there are tremendous benefits for wildlife and water quality within the riparian corridor.

However, in sensitive habitats like the prairie fens, found at a particular MNA Nature Sanctuary in Oakland County, these habitat architects can actually have a destructive effect by flooding and killing these rare plant communities and the rare species which occur within them. One of the two creeks that flow through the sanctuary has been dammed by beavers for over a decade and has enlarged the lake on the eastern side of the sanctuary. If left alone, the dams could eventually flood the fen and create an emergent marsh habitat comprised primarily of cattail, pond-lilies, and other wetland species. And though this type of habitat is common across the state, the transition in this particular location is not ideal.

Prairie fen (left) photo by Dave Cuthrell, Emergent marsh (right) photo by Joshua Cohen courtesy MNFI.

The prairie fen at this sanctuary is one of the last places on earth where the federally endangered Poweshiek skipperling makes its home. The loss of occupied prairie fen habitat at this sanctuary would have a catastrophic effect on the global population of these tiny butterflies.

After consulting with several conservation scientists about the issue, MNA conservation staff determined that the beaver activity constitutes a grave threat to the rare species found within the prairie fen, and that sanctuary management would include curtailing the flooding in order to maintain access to the sanctuary. This approach—prioritizing the needs of more rare species over more abundant ones—is commonly taken by conservation organizations at both the local and national levels.

Humans, like beavers, are capable of altering their surroundings in ways that most other species are not. Like the beaver and the butterfly which cannot know that in this place is nearly all that remains of the Poweshiek skipperling, humans too have a limited amount of knowledge to guide our activities. It is, however, with conscientious and scientific thought. Nature forces us to make some very difficult decisions at times—so as we work to protect Michigan nature for everyone, we must also recognize when one species requires more of our efforts than another.