The deadly disease that wiped out 90% of the Upper Peninsula’s bats, and a new hope for one species

brown bats

Ninety percent of the Upper Peninsula’s bats have died. That includes little brown bats like the one above, northern long eared bats, big brown bats, tri-colored bats and Indiana bats. A new study shows a glimmer of hope for the little brown bat. (Shutterstock)

This article was originally published on Great Lakes Echo

Steve Smith has explored old caves ever since he was a kid — usually illegally.

Now he just does it legally.

“Listen to the water dripping, and bats, and you can smell the timbers and almost visualize what the miners were going through. I have a passion for this.”

In 1992, when Steve was 37, he stood above the abandoned Millie Mine in Iron Mountain.

It was rumored to be “bottomless,” so he took that as a challenge.

Armed with 200 feet of rope and a couple of old flashlights strapped to motorcycle helmets, he and a friend made their descent.

They found the bottom about a hundred feet down, and were greeted by a hissing sound — bats.

It was a hibernation spot for up to 250,000 of them. He knows because he helped count them.

“There were all these bats flying, like just dozens of bats, hundreds of bats would be flying by the time we were through.”

Later, he heard the city of Iron Mountain was planning to fill in the mine with the bats still inside.  So he called Bat Conservation International, an organization dedicated to protecting bats and their ecosystems. Together, they saved the mine and all the bats inside.

Soon afterward, Michigan’s Department of Natural Resources offered Steve a job as a mine inspector.

“What I had been doing since I was a little kid, illegally sneaking into mines, turned into a 26-year career.”

Steve worked closely with bat biologists throughout his career, so he grew fond of bats.  He even thought they were cute.

But then something happened that neither him nor biologists could protect bats from — white-nose syndrome.

White-nose arrived in New York from Europe in 2006.  It has since spread to 33 states and seven Canadian provinces.

Smith and his colleagues at the DNR were the first to discover white-nose in Michigan in 2014.

Six years later, 90% of the Upper Peninsula’s bats have died. That includes little brown bats, northern long eared bats, big brown bats, tri-colored bats and Indiana bats.

“That’s a lot of years of work putting into this, and then to have it all end because of a fungus, it’s just horrible,” Steve said.

White-nose syndrome grows on bats while they hibernate in the winter, but it doesn’t actually kill them. Rather, the fungus irritates their skin, causing them to wake up in the middle of winter and burn up their fat reserves.  As a result, bats either starve or freeze to death when they leave the cave in search of food.

Smith now owns his own mine in Norway, Michigan.

Bats don’t live in caves during the summer, but he took me inside his mine to show me where thousands of bats used to live in the winter.

Much of the fungus’s spread can be attributed to people visiting caves without protection. The spores of the fungus stick to everything from your boots to your nose hair, so things like disposable suits and gloves are important when entering a cave, Steve said.

Especially since once the fungus reaches an area, there’s really no getting rid of it.

In Wisconsin, bat biologists tried stopping the spread by stripping down, showering and leaving the site with new clothes after entering an infected mine, but it was no use.

“It didn’t matter because when a bat leaves carrying white-nose and goes to another mine, it dumps the spores in the mine.  The bats themselves are carrying it,” Steve said.

In 2000, before Steve owned his mine, pictures of it were used in an advertising campaign to promote protection of bat habitats.

“This mine had clusters of like 2,500 to 5,000, clusters that were five feet long, and those are gone.  We’ll never see them again, because the bats are decimated by this white-nose.”

He once found 5,000 bats floating dead in a pool of water in a mine.  He called it “The Death Chamber.”  He watched another mine drop from 18,000 bats to 100 bats in just two years.

“We were in another mine, and when we got down into it there was like wind blowing pine needles all over, like piles of pine needles,” Steve said.  “It turns out they were bat bones, thousands of bat bones in piles.  There were so many dead bats that you couldn’t walk anywhere without seeing carcasses.”

There is no known cure for white-nose syndrome.

Experts have tried everything from an oral vaccine to installing air conditioning in mines to slow down the growth of the fungus.  They’ve even gassed mines to kill the fungus, but ended up killing everything else in the mine too.

But no matter what, bats always reintroduce the fungus when they return in the winter.

Even if by some miracle, a white-nose vaccine were given to all bats tomorrow, Steve says there’s no way to reverse the fact that 90% of them are gone.

And he says it may get worse for bats.

They’re expected to reach a 93-95% mortality rate before the population stabilizes.  And some species will likely be killed off entirely.

“The northern long-eared bat, it’s rare that we even find one, so they’re on the verge of extinction right now,” Steve said.  “And then the tri-colored bat, they’re almost gone too.”

But a new study by Giorgia Auteri, from the University of Michigan, shows a glimmer of hope for one species.

She found that the little brown bat has begun to show a genetic immunity to white-nose.

“It means that the ones that are surviving the disease seem to have genes that make them less susceptible to the disease,” Auteri said.  “And they’re probably going to pass some of those genes on to their offspring, so their offspring will also be less susceptible to the disease.”

This means little brown bats should eventually repopulate.  But with most bats only having one or two babies per year, Steve isn’t optimistic.

“It’s going to be a long-term thing, this isn’t going to happen like next year or next decade,” Steve said.  “I think we’re looking at a long term thing, like centuries.”

In the meantime, Steve says Michiganders should prepare for life without bats, because their loss will have a negative impact on both the environment and us.

“They’re extremely beneficial.  They consume insects, especially pest insects including mosquitoes, gypsy moths, forest tent caterpillars and corn borers,” he said.  “And all that stuff isn’t necessarily up here, but the more bats eat these insects, the less insecticides we have to use.”

According to a study done in 2011, bats contributed about $22.9 billion to the agricultural industry annually before white-nose syndrome.  The total economic loss since white-nose has not yet been calculated.

 Bats also eat disease-spreading insects and some even pollinate.

“I just don’t see where you can eradicate one entire population and not have drastic effects across the board, to all the animals,” he said.

Steve plans to retire this year and spend some time travelling around the country exploring caves — for fun.  But he’ll never stop advocating for bats.

“The biggest thing is to not attack bats.  If they’re in your house, don’t kill them,” he said.  “If you kill a bat and it’s a mother and it’s pregnant, we’ve just lost another chance to repopulate.”

This story was produced by a partnership of Michigan State University's Knight Center for Environmental Journalism and Interlochen Public Radio.

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Tue, 09/08/2020 - 9:24am

When I walk my dog in the evening, I always see bats flying around in Oakland county. Is this just a UP thing?

George Hagenauer
Tue, 09/08/2020 - 10:21am

How do urban Bats winter? Bat boxes provide some protection against white nose since they contain a small number of bats but do bats winter in the boxes? Should they have a different design or insulation? In the early 20th century huge bat houses were created in many cities to combat the mosquitos and other problems (most were sadly removed when the large scale DDT praying occurred) Maybe we should be looking at local solutions-small scale bat habitats to maintain a healthy bat population in urban areas and maybe also on rural farms.

Wed, 09/09/2020 - 9:23am

Who cares. Bats spread disease.

Fri, 09/25/2020 - 9:41am

All animals can spread disease - including humans. Bats are beneficial by eating a lot of insects like beetles, mosquitoes, midges, etc. that can harm us or damage crops. Some bats are also pollinators in other parts of the country and world. Your comment is ignorant of knowledge about a whole group of animals that have been around a lot longer than humans. You should read up on facts before commenting. Humans are by far more damaging to the environment - and ourselves - than other mammals. Bats are just one of many potential disease vectors for human transmission in nature. Disease is a way of natural selection and population control, and unfortunately, humans are one of the most overpopulated species on the planet.

Garry Willer
Wed, 09/09/2020 - 9:59am

Sulfur burning is very effective for killing molds and fungus lot of growers use it in their greenhouses and buildings. When you burn sulfur it puts a protective coating on everything with a very high pH . It might be worth a shot to try in the caves and mines.