Michigan Nature Monday: Vernal Pools

This week’s Michigan Nature Monday features the amazing natural habitat of vernal pools. The Michigan Nature Association has been a lead partner in the Michigan Vernal Pools Partnership for several years, and we are proud to have added to that commitment this year with a dedicated staff member – our Michigan Vernal Pools Partnership Coordinator–and the production of the Ephemeral video, produced in partnership with the award-winning videography team of Fauna Creative.

If you have spent time exploring Michigan’s forests in the spring, you may have come across small, shallow pools of water scattered throughout the landscape. These small wetlands are called vernal pools because they are typically filled with water in the spring (“vernal” means spring) but they usually dry up and “disappear” during the summer. Vernal pools are special types of wetlands– because they regularly dry up and are usually isolated from other wetlands and waterbodies, vernal pools cannot support permanent fish populations. Due to the lack of fish predators, vernal pools provide critical habitat for certain animal species that rely on these fishless habitats for their survival and/or reproduction. These include a number of invertebrate and amphibian species, such as fairy shrimp, wood frogs, spotted salamanders, and blue-spotted salamanders. Vernal pools also provide habitat for many other animal and plant species, including rare, threatened, and endangered species. 

Vernal pools play an important role in maintaining healthy forest ecosystems. Because they provide habitat for diverse and unique animal species and provide other important ecological functions, some have referred to vernal pools as the “coral reefs of Northeastern forests.” However, these vernal pools are vulnerable to a number of threats and are not well-protected under current wetland laws and regulations.

If you are interested in learning more about vernal pools and efforts to protect them, visit mivernalpools.com

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 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

Celebrating Michigan’s Many Bats

Michigan is home to nine different bat species, nearly one-fifth of the total number of species in all of North America. There are many reasons to appreciate bats, from the essential pollination and pest control services that they provide, to the fact that they are the ONLY flying mammal on earth. During Bat Week, October 24-31, 2022, you can help Michigan bats by dispelling some common misconceptions about bats.

• Common Misconceptions:
• “Blind as a Bat” – although most bats have small eyes, they can actually see just fine. And with the aid of echolocation, they are able to find fast-moving insect targets at night!
• Disease carriers – Not only does the U.S. Center for Disease Control and Prevention note that fewer than 6 percent of bats tested were carriers of rabies, the fungal disease known as white-nose syndrome, which is the leading cause of population decline among many North American bats, is much more likely to be transmitted to bats from human interference with their habitat.
• They ‘vant’ to suck your blood – only one species of bat (found in Mexico and South and Central America) has been known to bite humans, rarely, as they primarily feed on cattle.

Northern Long-eared bat photo courtesy Jill Utrup, USFWS.

Northern Long-eared Bat

Learn more about the critical role that bats play in the ecosystem, and share with your friends and family all the ways that bats are beneficial, by learning more about some of Michigan’s bat species below, and at batweek.org!

The northern long-eared bat is a federally threatened bat with a wide range. Found in 37 states in the U.S., these bats live in boreal forests for summer foraging and roosting, and caves for hibernation.

Although there are many threats to the species including habitat loss due to logging, the predominant threat by far is white-nose syndrome. According to the U.S. Fish & Wildlife Service (USFWS), if this disease had not emerged, it is unlikely the northern long-eared bat would be experiencing such a dramatic population decline. Numbers of northern long-eared bats, gathered from hibernacula counts, have declined by 97 to 100% across the species’ range. The USFWS is currently considering reclassifying these bats as endangered because of the threat of white-nose syndrome. Learn more about this classification process by clicking the link here.

Tricolored bat photo courtesy USFWS.

Tricolored Bat

Michigan’s eastern pipistrelle, also known as the tricolored bat, is so named for the multi-colored individual hairs of its fur, tricolored bats appear uniquely yellow-orange in contrast to other more brown-looking bats. Their “fluttery” flight pattern means that these small bats can be easily mistaken for large moths, according to the University of Michigan.

However, as one of the state’s primarily cave-hibernating species of bat, the tricolored bat has experienced significant population decline over the last 15 years, due primarily to the spread of white-nose syndrome. The fungal disease interrupts the bats hibernation cycle, causing them to become active and deplete their energy before there are available food sources in the spring. Once common across its range, estimates suggest that these bats have seen up to a 90% decrease in population since white-nose syndrome was first detected in 2006. Because of this, the U.S. Fish and Wildlife Service has proposed to list the tricolored bat as endangered under protection of the Endangered Species Act. Learn more about the process for classification by clicking this link.

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!

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.