Biologists recently announcedthat they have detected a fungus lethal to bats in Yellowstone National Park. Commonly called white-nose syndrome, the disease has already killed millions of bats in North America. The little winged creatures may not seem like a big part of ecological health. But as KHOL-Jackson’s Sophia Boyd-Fliegel learned from University of Wyoming bat researcher Riley Bernard, they’re a bigger part of the ecosystem than one may know. Bernard was in the field this summer.
This conversation has been edited for length and clarity. – Ed.
Sophia Boyd-Fliegel (KHOL): Describe what it was like to be there. I know you were expecting to find evidence of the disease, but what was that like for you? Someone who’s worked with bats for 20 years.
Riley Bernard: I think that kind of ecological trauma has definitely been present where, when I started my work in Tennessee, which was in 2011 for my PhD, the fungus and disease hadn’t quite made it there yet. And in a matter of just two seasons, I went from capturing 150-plus northern long-eared bats. At a couple of sites, to nothing and just seeing complete devastation, seeing bats trying to do something to get away from this fungus and coming out to the outside of a cave wall and freezing to death. Like it’s definitely the stuff of nightmares.
SBF: This disease was first found in New York in 2006 in North America. And then it spread super quickly and now it’s in almost all counties in Wyoming. Why should the general population of humans be worried about that quick spread?
RB: All the bats in Wyoming eat insects. We’re finding some really cool indicators of bats eating agricultural pests and livestock pests in and around Wyoming. A lot of our ag is for livestock production, but those bats are eating the pests. That would be a big issue for farmers and ranchers. And so you can imagine that if, by 2012, we had the estimate of 6 million bats lost [and] if that estimate is still true and it’s just doubling, we’ve lost over 10 million bats to this disease. And if bats are insect predators, that means that they’re gonna eat things like mosquitoes, various ag pests. We think of fall armyworm, which is a huge one for our crops. That means they’re going to have an increase in pest insects, which then means that it affects us as humans, whether it’s mosquitoes and getting diseases from those mosquito bites, or our livestock getting diseases, or it’s us having to consume fruits and vegetables that have a higher amount of pesticides on them. So just having bats on the landscape is really critical for functioning ecosystems, for lowering our disease burden, as well as our pocketbook
SBF: And, and are you actually seeing that? Like, are farmers actually talking to each other and, for lack of a better word, freaking out about the bat population?
RB: Yeah, I would say there’s a lot of folks, especially in the Southeast, that have been ramping up the production of putting bat boxes in orchards just so that they can be more productive. So there’s a lot of pecan orchards, as example, in Georgia and other places in the South with organic farmers, so they want to make sure that they have bats on the landscape so they don’t have to have lower product yields.
SBF: So white-nose syndrome is from this fungus [Pseudogymnoascus destructans], commonly called PD. What does that actually do to bats?
RB: This fungus does really well on mammalian tissue, and it starts eating away at that tissue. And when the bats are becoming distressed and they’re in hibernation, they’ll come out of torpor more often. So they’ll burn through those fat stores that they’ve perfectly planned to survive winter. So in Wyoming, that’s November till classically maybe the end of March, early April. That leads to them starving or leaving the cave to find food or to do these kinds of sickness behaviors. They don’t do very well and that’s what leads to decline.
SBF: What does your research tell you about how national park populations might fare into the future?
RB: We have several lines of evidence that suggest that our Western populations of some species are likely to get hit just as hard as what we’ve seen in the Eastern portion of the range. But there’s some element of species ecology that might help them out. Our little brown bats, which are the species that are in Yellowstone and in the Tetons, have been identified to have the fungus on them [but] may be able to withstand the disease a bit better because they’re not overwintering in these large congregations at these sites that we’ve seen in the Southeast or in the East. So that might be a saving grace, but we don’t know. We’re in what’s called the invasion zone and we’re starting to turn into endemic or established areas, but it’s still pretty new, even though it’s been in the state for almost 10 years now. For little browns, they are the ones that are getting hit really hard. They’re the ones that we’ve done a lot of proactive intervention on with vaccine trials and things like that. But in the Eastern portion of the range, so like in Vermont, New York, Ontario, they’re fighting populations that are persisting. So they’ve had big losses. But they’re starting to slowly creep up again, which is really hopeful.
SBF: Is there anything that tourists can do in these landscapes to help with that population?
RB:. Just being aware, making sure that when you’re going from one place to someplace else, clean your shoes, clean your clothes, make sure that you’re not potentially an individual that’s moving what are called fomites is the scientific term of little things that can hitch a ride on humans or pets or animals. There’s also just reporting if tourists see something weird that’s happening. That’s a huge one. When I was working in Great Smoky Mountains National Park, that was kind of how we started seeing and finding out that white-nose syndrome was having a huge effect on the populations because bats were flying around during the daytime, doing things they shouldn’t do. Tourists were reporting that to the wildlife biologists. Because I’ve been doing bat work now, as you said, for 20 years, I’ve seen amazing work and research that have come out to try to solve this problem as well as other problems that bats face. There are things like cleaning them or treating bats directly, whether it’s UVing their wings because that does tend to kill the pathogen, doing vaccines like what we’re working on now in the Tetons, even doing things like putting up bat boxes and making habitat to try and help those individuals that do survive the winter to be able to have a great place to raise their young.
SBF: Thank you, Dr. Bernard, for taking us through that. I’ll be interested to see what happens next.
RB: Thank you so much for the invitation to share about bats and white-nose syndrome.
