Editor’s note: Last month, the Department of Natural Resources reported 60 endangered and 60 threatened species in Michigan. This week, in honor of Earth Day, we will share the stories of some of these animals and the work being done to help save them.
GRAND RAPIDS, Mich. (WOOD) — They may not be the cuddliest creature or even the most pleasant to look at, but bats play a key role in our ecosystem and several bat species have been decimated by a major fungal outbreak.
White-nose syndrome is caused by a fungus called Pseudogymnoascus destructans. It was somehow carried over from Europe and first discovered in North America in 2006. Ever since, it has ravaged several bat populations.
Winifred Frick, the chief scientist for Bat Conservation International, says little brown bats and tricolored bats have been hit hard by white-nose syndrome, but the northern long-eared bat has been hit the hardest and is heading toward extinction.
“We’ve lost over 95% of the northern long-eared bats that we used to know would hibernate underground during the winter,” Frick told News 8. “They just disappear after several years of the fungus getting to where they hibernate.”
The northern long-eared bat lives all across Canada and from Wyoming all the way through the east coast. According to the DNR, white-nose syndrome was first confirmed in Michigan in 2014. It is now found in approximately 80% of the bat’s total range and is expected to completely cover the range by 2030.
Northern long-eared bats were added to the U.S. Endangered Species List at the end of 2022. Federal protections went into effect on April 1.
Frick admits that the outlook doesn’t look good.
“The numbers look really grim, to be honest,” she said. “Once they develop the fungus or get infected, it’s pretty much fatal. So really, it’s only a matter of time before it spreads to all of the colonies.”
The fungus is so effective because it affects bats when they are their most vulnerable — during hibernation.
“It is actually a cold-loving fungus. So, it can persist in the caves and mines where bats hibernate. Even though bats are mammals like we are, when they go into a true hibernation … they drop their temperature to just above freezing as a way of saving energy,” Frick said. “If they come into contact with the fungus, because it might be persisting on cave walls, the fungus will start to grow on their skin tissues, and it basically eats into their skin tissues.”
She continued: “And that causes a cascade of physiological responses where the bats basically start to arouse from hibernation too frequently and they burn up their fat stores because it takes a lot of energy to come out of hibernation. … Essentially, they starve to death before spring. So, places like Michigan where we have long, cold winters, are some of the places where we see the highest levels of mortality across these different species.”
Frick says losing major bat populations could have several ecological effects. Bats in warm climates are natural pollinators for plants and can also spread fruit seeds through their waste which helps regenerate forests. For Michigan and the United States, it’s all about the bugs.
“In the U.S., most of our bats are insectivorous, and insectivorous bats are important consumers of nocturnal insect pests, including agricultural insects,” Frick said. “There are studies that show the economic value that bats offer in the United States to the agricultural industry is in the billions every year. They help improve crop yields and reduce the amount of pesticides that farmers put on.”
There is a glimmer of hope for the northern long-eared bat. And it just so happens to be in Michigan. Despite exposure to the fungus for nearly a decade, tens of thousands of bats that hibernate at the Tippy Dam in Manistee County have shown no major issues. Researchers told Bridge Michigan that they don’t know exactly how these bats have managed to survive this epidemic.
Allen Kurta, a biology professor at Eastern Michigan University, has been studying bats for years. He said the Tippy Dam makes for an unconventional hibernating spot for bats. Those differences that make it a poor spot to spend the winter may be the key to saving these bats.
Typically, bats prefer to hibernate underground in places like caves, spending winter in total darkness and tucked away in rock crevices. But Tippy Dam is different. It has smooth, concrete walls instead of crevices and ventilation holes that let in light.
Haley Gmutza, a former EMU grad student who is now working on her Ph.D. at Ohio State University, told Bridge that she thinks the light is the factor. In pitch-black, bats will wake up at any given time, but the light exposure keeps them on a 24-hour rhythm. Gmutza hypothesized that if they all wake up at the same time, they can share body heat and burn less fat.
Kurta is working with the National Wildlife Health Center in Wisconsin to run some tests, comparing 30 bats collected from Tippy Dam to 30 from a different site. He hopes to determine if a generic difference between the bats or the fungus found at Tippy Dam plays a role.
“It’s a ray of hope,” Gmutza told Bridge. “Whenever you talk about white-nose, it’s just like everything is bad. The colony had died out. This mitigation method didn’t work. It’s a parade of bad news. But Tippy is not.”
This story is the third part of a five-part series. See the full series here.