Bat Gadgetry: High-Tech Solutions to a Deadly Problem
Since white-nose syndrome was first detected in the early 2000s, it’s spread to caves across the continent. Now, the fungal infection is threatening the extinction of several bat species. But high-tech solutions are in the works.
Audio equipment helps scientists monitor bat populations by listening to them. Artificial light is being used to draw in bugs around caves, making an easy meal for bats weakened by disease.
White-nose syndrome is devastating. But it's driving research that could advance human’s understanding of bats, and of wildlife disease as a whole.
Host: Morgan Springer
Producer: Patrick Shea
Editor: Morgan Springer
Additional Editing: Dan Wanschura
Music: Gillicuddy and One Man Book
MORGAN SPRINGER, HOST: In the early 2000s, bat biologists in upstate New York headed deep into a cave where they found an unpleasant surprise.
TINA CHENG: Instead of seeing, you know, tens of thousands of these bats roosting over the ceiling, they discovered heaps of dead bats on the floor.
SPRINGER: That’s Tina Cheng, a data scientist with Bat Conservation International. She says those biologists had stumbled upon the first known case of a disease that’s now called “white-nose syndrome.”
CHENG: It’s a fungus that grows on the skin of bats. So it actually digs into their epidermal tissue. And so when they’re really highly infected they actually have these little white fuzzy patches of fungal growth on their noses. Hence the name white-nose syndrome.
SPRINGER: That early case in New York killed off almost an entire colony of an endangered bat species. Today, the fungus has spread to caves all across North America. And Tina says when a cave gets infected, that spells disaster for the bats inside.
CHENG: The mortality can be greater than 90 percent on average at a site. And so when you have a colony that can get into the tens of thousands, that is just unprecedented carnage.
SPRINGER: This is Points North: a show about the land, water and inhabitants of the Upper Great Lakes. I’m Morgan Springer.
Right now, the U.S. Fish and Wildlife Service is deciding whether to put another bat on the endangered species list: the northern-long eared bat. Here in the Upper Great Lakes, it used to be abundant. But its population has collapsed in recent years because of white-nose syndrome.
PATRICK SHEA, BY-LINE: To try and prevent its extinction — and the extinction of other bat species — scientists first need to learn more about the problem and test some solutions.
SPRINGER: That’s Patrick Shea. Hey Patrick.
SHEA: Hi Morgan.
SPRINGER: Today, we’ll check out technology being used to track the spread of this disease — and see if it gives bats a boost.
SHEA: To get a first hand look, I took a trip about as far north as you can go in Michigan: the Keweenaw Peninsula.
BREANNA GUSICK: So just be careful, the steps will be a little slippery where the water is.
SHEA: I’m walking down a steep, soggy staircase into total darkness - and I’m following Breanna Gusick, a biologist with Bat Conservation International.
SHEA: We’re about a half mile deep in the Delaware mine: one of many abandoned mine shafts in the region. A hundred years ago, people came down here in search of copper. But we’re looking for something else.
BREANNA GUSICK: There’s a bat right above your head.
SHEA: Oh yeah.
SHEA: It’s late May, and most of the bats hibernating here have already left the mine. But there are still a few here and there, hanging from the ceiling, bundled up in their own wings.
Some of them stir and twitch – Breanna says that means they’ll wake up soon.
GUSICK: He’s not even shivering so he’s not trying to wake up. He is sleeping.
SHEA: Wow he is so motionless. He/She.
GUSICK: Yeah they don’t move, it’s crazy.
SHEA: That is nuts.
This little brown bat is still as a statue — it doesn’t even seem like a living creature. Until…
GUSICK: Looks like he’s starting to go to the bathroom. Now if this one did have white-nose, we’d see it up front like around the mouth area.
SHEA: The way white-nose syndrome kills a bat is by interrupting this stoic sleep. Because when fungus grows all over your face and up into your nostrils, you can imagine that’s a little uncomfortable.
When a bat wakes from hibernation, it needs to get its body temperature back up. That burns energy it needs later in the spring. Infected bats usually die of exhaustion and hunger - either right there in the cave, or shortly after leaving it.
And when bat populations started declining around here, people noticed the difference.
KYLE SEPPANEN: I remember as a kid seeing bats, because we used to have one of those flood lights outside.
SHEA: That’s Kyle Seppanen. He’s the wildlife coordinator for the Keweenaw Bay Indian Community.
SEPPANEN: And we’d see bats swarming. And you’re like, ‘oh, the bugs ain’t too bad.’ But it feels like the past couple of summers, especially, you’re walking out there and you’re just hitting them left and right.
SHEA: Kyle says white-nose syndrome is to blame for this – the disease started killing bats around here in 2014. And there’s evidence that fewer bats means more bugs. One little brown bat alone can easily eat up to 1,000 mosquitos in just an hour.
I’m riding along with Kyle as he monitors bats on the reservation, something he’s been doing for the past six years. And he’s not alone in noticing the buggier summers since then.
AUSTIN AYRES: Last year was the first time I ever put a mosquito net on my head because I was just so overwhelmed by it.
SHEA: Austin Ayres is a wildlife technician with the tribe.
AYRES: It almost felt like it was raining, just the amount of mosquitoes that were dropping on me – landing on my hands, my shoulders, my face. It was pretty overwhelming and that’s the first time I ever thought ‘wow, we’re having a problem with bugs right now aren’t we?’
SHEA: Austin and Kyle both agree that bugs can be a major nuisance. But they say the problem is a lot bigger than their own discomfort.
AYRES: You know, one of our relatives is suffering. And as Anishinaabe it’s one of our teachings that we are the caretakers of this land and the animals that inhabit it…
SHEA: Bats, specifically, are at the center of one traditional story that ties into the work Kyle and Austin do now.
It starts with the sun getting caught in a tree, stalling the sunrise. Then, a squirrel chews the tree’s branches, and frees the sun. But it comes at a cost.
AYRES: It got so burnt up that it couldn’t see anymore. And after it got burnt up and it couldn’t see anymore, Creator granted them echolocation and said ‘you’re going to fly just as good as the other birds. You’ll stay out at night because the sun will be too bright for you.’
SHEA: The squirrel had transformed into a bat.
SHEA: The really interesting thing about that to me is that the concept of echolocation is in that story.
AYRES: Yeah. We call it traditional ecological knowledge. The reality of it is that our people are so old and we’ve lived for so long that we’ve watched evolution occur. And so when we tell stories, especially traditional stories, it’s got that tied into it.
SHEA: Bats are really hard to count. They’re only out at night, many species live deep in caves during the winter; they’re pretty mysterious creatures. In the past, researchers would walk into caves during hibernation to try and get a rough count of the bats on the ceiling. But how can you be sure you don’t count the same bat twice? It’s tricky.
So Kyle uses sound to track bat populations – audio recordings of bat calls. That doesn’t give him an exact number of bats. But it does indicate when there’s an increase or decrease in bat activity. It also shows him where the most popular bat hangouts are. We walk to the edge of a wetland, with a small creek winding through it.
SEPPANEN: So this spot is actually part of the Kelsey Creek system. It’s like a natural flyway all the way from Lake Superior, all the way inland.
SHEA: Like a corridor the bats use?
SEPPANEN: Right, yeah. So this spot’s been heavily impacted by beaver use, so there are lots of dams, lots of open pockets of water for bats to come and take a drink out of. There’s insects all over the place here. So I have a detector sitting over next to that dead tree that’s standing right there.
SHEA: That detector looks pretty simple: just a long pole with a microphone on top. But what it does is very high-tech, and it’s the best way to track the spread of white-nose syndrome.
SHEA: As the Anishinaabe have known for thousands of years, bats get around using echolocation. They make sounds that bounce off of objects and back to their ears. That tells them where not to fly, and where the bugs are. But those are sounds our ears can’t pick up. These acoustic monitors record echolocation calls, and represent them visually.
Back at his office, Kyle shows me how the shape of the sound tells him which species of bat is making it.
SEPPANEN: So big brown bats, you can tell they’ve got that big steep slope on it. And at the very end of it, they always come down. The pitch always comes down.
SHEA: Kyle plays an amplified version from his computer.
SHEA: Ok, yeah, let it rip.
SHEA: That weird, tapping, laser-beam sound: that’s the call of the big brown bat.
SEPPANEN: Here’s a slowed down version of it.
SHEA: The tribe’s acoustic monitors show a decline in these calls, as well as calls from little brown, tri-colored and northern long-eared bats. Those species are all highly susceptible to white-nose syndrome.
Kyle uploads these bat calls to an international database so biologists can see the big picture. They can go search for white-nose syndrome in areas that seem to show a decline. And odds are, they’ll find it.
But this acoustic monitoring is really valuable on a local level, too, because it shows where the most popular spots for bats are around the reservation. That will hopefully help in the future. If some sort of cure is discovered, Kyle will know the best places to find and treat bats.
Bat Conservation International is trying out one treatment. Back at the Delaware mine, Breanna Gusick takes me to her study site.
GUSICK: I’m going to actually go and check all my equipment. But we can’t actually go up to it from here, we’ve got to go up above ground and walk to get to it.
SHEA: We begin the climb out of the mine shaft. The project we’re about to see is part of a nationwide experiment. Tina Cheng, who you heard from the intro to this episode, was involved in starting what she calls the “fat bat program.”
CHENG: This came about from something we call the fat bat hypothesis. So there was a researcher in Pennsylvania who noticed that some of the bats that were actually surviving and persisting through the disease wave, he noticed that they were really fat. Like much fatter than he had noticed previous to the disease wave.
SHEA: So Tina and her colleagues wondered if maybe that was the key. Get the bats fat enough to make it through the winter, even if they’re infected with the fungus.
We come out of the dark cave into the wind and sun. I follow Breanna to another entrance to the mine. There are solar panels and high-tech research gear, set up right in the midst of antique mining equipment. You can still see the wooden platform where trains used to load copper. So it’s this strange mix of historic artifacts and futuristic gadgets.
GUSICK: I’m going to check the light first since it’s almost nine o’ clock. I want to make sure it’s set up.
SHEA: An ultraviolet light bulb is programmed to attract swarms of bugs each night. Breanna calls it a “bug buffet.” When bats emerge weakened from white-nose syndrome, the hope is that this cache of insects will build up their strength.
The light flicks on, as planned. It’s a small, halo-shaped bulb. The previous winter, biologists inserted tiny microchips into the backs of about 300 bats here. When the bats fly through a hoop-shaped scanner near the bulb, it detects those microchips and identifies individual bats.
GUSICK: If the bats keep coming back to the same places to hibernate and they’re tagged, we see when they come back and leave and hopefully can see their survival too.
SHEA: Breanna shares the data from the scanner with her colleagues. People like Tina Cheng, who sifts through data from bug buffets in seven different states.
CHENG: And so we’re really trying to expand geographically to first test the concept of ‘if you build it, will they come?’ If you build it, will the bugs come? Will the bats come? And will the bats actually use these bug buffets to forage?
SHEA: I asked if the bug buffets seem to be increasing bat survival. But they’ve only been trying this for three seasons, and Tina, like a good data scientist, says it’s too early to tell. Plus, she doesn’t want to give too much away.
CHENG: We’re actually working on publishing our initial results. But spoiler alert that we have found that bats do indeed come. We have evidence that bats are actually using these bug buffets.
SHEA: White-nose syndrome is by no means a good thing, but Tina says there’s a bright side. Scientists are gaining a lot of critical knowledge as they respond to this disease.
CHENG: Oh, one hundred percent. This has driven a ton of research to help us understand bat natural history, bat immunology, and I will say that even beyond bats, wildlife disease is a discipline that is gaining a lot of attention, not only because it often links up with human health but because it’s actually placing a lot of pressures on global biodiversity.
SHEA: There’s other research looking into vaccines and fumigation to treat the fungus directly. But in the meantime, Tina’s hopeful that these bug buffets will lead to fatter bats and less carnage in caves.