Spring nights come alive at a Laingsburg nature center as temperatures warm. That means frogs are waking up, and their chirps and croaks are reverberating through Mid-Michigan wetlands.
As the sun set on an April night, more than fifty people gathered in a barn at the Corey Marsh Ecological Research Center, wearing rubber rainboots and headlamps.
They were all preparing for the evening’s Frog Walk tour through the marsh. Researchers from Michigan State University would be leading the group of hikers to listen for the spring’s first frogs.
Fisheries and wildlife professor Alexa Warwick introduced herself and began telling the group what to expect for the evening.
“The frogs are already calling tonight. You probably heard that when you were coming in,” Warwick said. “We've got a great night ahead of us.”
Photos of the frogs and buttons mimicking their sounds lined a table at the front of the barn. Warwick explained which frogs were active now and which would later in the season, pressing each button and describing their calls. She pointed out one for the spring peeper.
“Most people have probably heard of them. You can hear them in a big chorus out there, very high pitched peeping noise.”
She then led the group through the winding, muddy marsh trails, while hikers—whose ages ranged from a four-year-old girl to an elderly couple—kept an ear out for those croaks and trills.
As the group wandered deeper into the wetland and further from roads and homes, the nature center became lively with frogs, sandhill cranes, crickets and other critters calling out into the night.
But one species’ song overpowered all the other animals: the spring peepers.
“They are making some very loud noises,” Warwick said. “I don't know if anyone heard any other species, but I was not able to hear any other species.”
Fifth-grader Aubrey Garber didn’t mind the ruckus.
“I liked listening to the frogs over in the way back,” she said after the hike.
Despite the almost deafening volume, Warwick says their racket is a good sign.
Frogs are bioindicators. That means if they’re not doing well, the greater ecosystem may be hurting. But Warwick said humans can help.
“Reducing the amount of pesticides and herbicides that are using in your landscaping or in areas that you're going really can help frogs and toads,” Warwick said.
Corey Marsh was a muck farm research center for MSU from 1941 until 2012, and people sprayed a lot of chemicals on the land to do that work. People also drained the wetland, so they could grow vegetables, which destroyed wildlife habitat.
The university was planning on selling the property to the Department of Natural Resources to become part of the state game area, but a professor named Jen Owen had a different idea.
When the university stopped draining the land, water levels began to rise, and animals came back. Warwick said Owen saw its potential for student and public engagement.
In 2018, the station became a wetland ecological research hub, where students and researchers are now studying the effects of spraying those chemicals during its muck farm days, along with the impacts of invasive species.
Warwick said invasives can disrupt bugs and other things frogs eat.
“Some invasive species can specifically secrete a chemical that hurts frog eggs,” Warwick said. “That's something else to keep in mind. It's not just the immediate impact on invertebrate communities that the frogs might be eating, but also the toxins that might get into the water because of those invasive species.”
Warwick said amphibians are sensitive to the environment, and climate change—inconsistent rain, drought and rising temperatures—is hurting frogs.
She recommended people to upkeep or restore wetland habitats, including temporary seasonal spots like vernal pools that could pop up in backyards.
Warwick, along with her partners at the university, will be hosting another Frog Walk on April 23 at the Michigan Wildlife Conservancy in Bath Township as part of the MSU Science Festival.
As for the marsh, its hiking trails are always open, and researchers often host tours for school groups and the rest of the public.
