Scientists search for ways to battle deadly fungus devastating North America’s bats

The association between bats and Halloween dates back thousands of years, based on the superstition that the flying mammals are omens of death. But for nearly two decades, North American bats have been facing a deadly threat themselves: a fungal disease called white-nose syndrome. Ali Rogin speaks with New York Times columnist Carl Zimmer for more.
John Yang:
The association between bats and Halloween dates back thousands of years. It’s based on the superstition that they’re omens of death. And now, as Ali Rogin tells us, North American bats are facing a deadly threat themselves.
Ali Rogin:
For nearly two decades, bats across North America have been decimated by a deadly disease called White-Nose Syndrome. Patches of pale white fuzz caused by a fungus appear on infected bats. First observed in 2006, the pathogen quickly began spreading after appearing in New York State. It has since killed millions of bats across the country.
Yet according to recent reporting in the New York Times, for the first time in years, researchers are feeling hopeful in their fight against the disease. Carl Zimmer is a columnist for the New York Times and recently wrote about this. Thank you so much for joining us. So how did white nose syndrome begin and why did it spread so quickly?
Carl Zimmer, Columnist, The New York Times:
It originated in Europe, and in Europe, the bats there are able to fight it off. Somehow this fungus was able to get across the Atlantic. It’s possible a traveler was exploring a cave in Europe, got it on his boot, and then they traveled to New York and the spore was spread here. But once it got to the United States, the bats themselves started to spread it across the entire continent.
Ali Rogin:
You write about the shock that some researchers had when they came upon the first examples of this. Can you tell us a little bit about what it was like for those researchers who entered these caves in the United States and saw the toll that this disease had taken on the bat population?
Carl Zimmer:
The first biologists who discovered white-nose syndrome were just shocked because they would literally walk into a cave that they had been visiting for winters studying hibernating bats for years, and there would be a pile of dead bats on the cave floor. They would see caves that were completely empty.
And then this fungus made its way across North America and further west. Biologists knew it was coming. And then one winter, they’d come into their caves and they too would see these huge piles of bat bodies. Millions of bats have died as a result of this.
Ali Rogin:
And it’s run rampant for so many years. But why are researchers now hopeful that they might have made some progress in tackling this disease in North America?
Carl Zimmer:
We’re at a very dire point now because some species are down over 90 percent and over half of bat species in North America are at risk of extinction. And white-nose syndrome is part of that threat. But it does seem like there might be several different ways that wildlife biologists could actually help to restore the bats. And those projects are going on right now.
Ali Rogin:
And tell us about those projects. What sort of solutions have researchers found have been helpful?
Carl Zimmer:
One possibility is to use a non-toxic chemical that is sprayed on the walls of abandoned mines and other places where bats like to roost for the winter. And what happens is that this chemical spray basically arrests the fungus. The spores just can’t attack the bats. They’re just inert, basically.
And some preliminary studies have showed that this actually ends up allowing more bats to survive the winter and not get sick with white-nose syndrome. So that’s one solution.
Another is to actually bring in more cold air into these shelters where they hibernate. Because at colder temperatures, it seems that bats are able to go into a deeper state of hibernation and they can withstand the fungus attack. And in the spring, when they come out of hibernation, they can rebound.
Ali Rogin:
Let’s take a step back and talk about the importance of bats to the ecosystem and why it matters so much that this massive die off be stopped.
Carl Zimmer:
And a lot of people are scared of bats. They would rather not deal with bats near them. But you have to remember that bats are essential to many ecosystems. Some species of bats will pollinate flowers, so these flowers just totally depend on the bats to spread them around. And bats also eat vast amounts of insects.
And if you take bats away, those insects can explode. We’ve actually seen this in action where in counties where there’s high levels of white-nose syndrome. And so bats are disappearing. The insects are booming so much that farmers are actually having to put more insecticide on their farm fields. And that can actually lead to human health problems.
And so you can see how if you let bats disappear, there are going to be a whole bunch of problems, just not only for nature, but for us as well.
Ali Rogin:
You mentioned earlier how this disease likely started in Europe and traveled to North America. What does that say about the dangers of travel in terms of spreading these pathogens far and wide?
Carl Zimmer:
We have to recognize that we all live on the same planet. And as far away as Europe might seem from us or China or any other place on earth, diseases can get around. It can take just one fungal spore one boot to endanger all the species of bats on a new continent.
And, you know, we’ve seen that with human diseases as well. Just with COVID for example. COVID started in one place in China, and then it was soon all around the world. And so if we’re going to try to lessen the threat of all of these pathogens, we have to be thinking globally.
Ali Rogin:
Carl Zimmer with the New York Times with a hopeful story about an important species. Thank you so much.
Carl Zimmer:
Thank you.