Could Heating Caves Save The Bats? Tens of thousands of bats have been dropping dead in the Northeast, all exhibiting symptoms of the poorly understood "white-nose syndrome." Ecologist Justin Boyles explains how installing heated boxes in caves could help hibernating bats with white-nose syndrome survive the winter.
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Could Heating Caves Save The Bats?

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Could Heating Caves Save The Bats?

Could Heating Caves Save The Bats?

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You're listening to SCIENCE FRIDAY on NPR News. I'm Ira Flatow. We have been following this really unusual story. We've covered it a couple of times in the last couple of years, where scientists have noticed droves of dead bats. In Upstate New York, the creatures were reduced to skin and bones. And they had this one strange marking that they all - bats -they all shared. It was a mold-like, white substance on their noses and wings. These symptoms are the calling card of what scientists are calling white-nose syndrome. But they still don't know if it's a white fungus that causes the death, or is merely an opportunistic infection because the bats are so weak from something else.

And since those first sightings, hundreds of thousands of bats have died. The syndrome has spread to caves all over the Northeast. And just recently, scientists spotted it as far down as West Virginia. And soon, it could hit big bat caves that bat experts say are crucial harbors for endangered bats.

But my next guest has a creative idea on how we might be able to turn this epidemic around and keep white-nose syndrome bats alive. And this is in research out this week in the journal "Frontiers in Ecology and the Environment." Justin Boyles is a graduate student at the Center for North American Bat Research and Conservation in the Department of Biology at Indiana State University in Terre Haute, Indiana. He joins us by phone there. Welcome to SCIENCE FRIDAY.

Mr. JUSTIN BOYLES (Grad Student, Center for North American Bat Research and Conservation, Indiana State University): Thank you for having me.

FLATOW: How far have these bats - how far has this illness spread now?

Mr. BOYLES: You covered it pretty well. So it's being found from maybe New Hampshire in the North, down to West Virginia and even Virginia, it looks like now, in the South.

FLATOW: And the bats just don't go into the caves like we think all winter, do they, and hibernate the whole winter there?

Mr. BOYLES: Well, yeah. So hibernation isn't a static state. It does involve another phase, which we call an arousal phase. So during these, the bats actually, they warm up, bring their body temperatures back to the normal level. So it's not just a, you know - it's not just hibernation for six months straight.

FLATOW: And you created a computer model of how they hibernate.

Mr. BOYLES: We did. Basically it's a video game, you could think of it, without the cool graphics. So we simulate bats burning energy throughout the winter.

FLATOW: And do the bats arouse for any particular reason during the winter?

Mr. BOYLES: This is a question that goes way back in the literature. We don't actually know why they arouse. We know what they do while they're aroused. So they can do lots of things. They can mate, urinate. There's even some evidence now that they have to sleep. They have to come out of hibernation, oddly enough, to fall asleep. So there are lots of things they do during these arousals, but we don't really know what causes them yet.

FLATOW: So take us through what happens once they are in an aroused state.

Mr. BOYLES: I'm not sure what you mean by that.

FLATOW: Well, let's - well, you say they're aroused. Do they get up and move to a different part of the cave? Do they leave the cave? What happens?

Mr. BOYLES: Sure. Well, besides all those things I've already mentioned, there is one thing that's sort of pertinent to the discussion that we noticed here in the Midwest, and that is that these bats, when they do warm up, they tend to move to a warmer spot in the cave. So we call this an active area. And it make sense. If you're trying to stay warm, it's a lot easier to do that where it's warm than where it's cold. So it could save them a lot of energy to move to these warm spots.

FLATOW: Yet there are bats, and the ones that we've talked about over the years here, there are bats that move out of the cave and they die of starvation or freezing to death.

Mr. BOYLES: Sure. So that appears to be the response of these affected bats. So when they get to their end of their life or the end of their fat and they just have no other option, they pick up, leave the cave and go look for food - which, obviously, in New England in you know January there isn't lot foot out there. That's the response at the end.

FLATOW: And you're saying that you have come up with an interesting idea to keep these kinds of bats alive.

Mr. BOYLES: We hope so. What we've actually suggested is that we take this idea that I was talking about a second ago, these warm spots that are in the caves where the bats normally go, and build artificial versions of that, and build them to the extreme. So in normal caves in the Mid-West, we might see these warm spots at 50 degrees Fahrenheit, give or take. We're talking about putting artificial spots that are closer to 80 degrees Fahrenheit. So we're just sort of mimicking what we see in nature, but extenuating it, doing it to an extreme.

FLATOW: So you want to bring room heaters, so to speak, into the bat cave.

Mr. BOYLES: Sort of, yeah. We're talking about probably little boxes. The prototypes we're building are in bat boxes. So these are the same thing a lot of people put on the side of their houses for bats to use during the summer, using one of those insulating it very well and putting a heater in it.

FLATOW: And hopefully you'll heat up the bat caves so that the bats don't fly out.

Mr. BOYLES: Well, no. We have to be very careful here. We don't want to heat up the entire cave.

FLATOW: Right.

Mr. BOYLES: The cave has to stay cold enough for the bats to hibernate. We want these to be really small spots, very localized. So it doesn't affect the entire cave micro climate. But it just gives them this option when they are in these arousals.

FLATOW: And have you tried to pilot test of this at all?

Mr. BOYLES: We are actually working on it right now. Fish and Wildlife Service funded a pilot study for us. We have the prototypes, and they're being deployed hopefully very shortly in a little cave system in Manitoba.

FLATOW: And how will the bats know that the boxes are there, and will the feel the warmth coming out of them?

Mr. BOYLES: Well, eventually. We think they will find them that way. What I sort of envision happening is, is if a few individuals find them - you can find a warm bat in a cave fairly easily. They're - tend to be fairly noisy. So if a few individuals find it, it won't be that hard for the other bats to find them. And if they notice a lot of bats are going to this one spot. They probably will learn where these warm spots are at.

FLATOW: Do you envision giving them food while they are there?

Mr. BOYLES: Well, no, we actually don't. This has been a suggestion, to give these animals food. But there are really two problems. For the most part, they don't eat during the winter. So, you know, during hibernation, bats normally don't do this. So that's not a behavior that they really have evolved. So we would be teaching them something new there. We've also - there's been some discussion of taking the bats out of the caves and feeding them, but that could just be a logistical nightmare to maintain enough bats that way, though probably no food.

FLATOW: You talk about in your paper and - about some possible problem with the idea that it might keep whatever the vector is, whatever is causing the death of these bats, instead of allowing the bats to be killed off, they might be able to survive, and infect other bats.

Mr. BOYLES: Sure, sure. So if we increase the survival and the bats make it through the winter, they could then transfer whatever it is - if it's the fungus or it's something else - to their colony mates during the summer. It looks like, or there's at least been a suggestion that this fungus, if it does turn out to be the fungus, doesn't grow very well above about 70 degrees Fahrenheit, give or take. And the bats experience temperatures much, much warmer than that during the summer. So the fungus might die back or not grow as well, which might mean it's not transmissible. So if that's the case, if it can't be transmitted during the summer, we really don't have to worry about that. That side effect isn't as big a deal.

FLATOW: What kind of reaction have you gotten from the science community about this?


FLATOW: Not good, huh?

Mr. BOYLES: Well, well let's say mixed. No, there are actually a lot of people that are on board with this. It's fairly controversial, or it's fairly unconventional maybe is a better word. So we're doing - you know, we're sort of going against a long-standing paradigm. And it is has been mixed. We do have a lot of support on this, and there are lot of people that are really interested in trying it because white-nose syndrome is such a huge issue in the Northeast right now that unconventional ideas -especially unconventional ideas that have support like this one does, (unintelligible) - are worth trying them. So we're working on it. We're slowly explaining this to a lot of people to try to build support for it.

FLATOW: Bob in Indian Head, Maryland. Hi. Welcome to SCIENCE FRIDAY.

BOB (Caller): Yeah. Bats chose their hibernation locations because they like that temperature and humidity. If it's too warm, their metabolism is too high and their fat reserves don't last out the winter. If the temperature is too high, is too low, they'll desiccate. I really don't see why warming the cave would help. There are caves - some caves are colder and some caves are warmer. And the bats chose their colder caves because that gives them the best survival.

FLATOW: All right, Bob. Let me get an answer.

Mr. BOYLES: Well, he knows his hibernation literature. I would say that he hit on this paradigm I'm talking about. And the recent literature is actually sort of moving away from that in the last three or four years, where we're getting away from this idea that colder is always better. But that's sort of a different argument. This goes back to, look, why would we only want to heat localized areas? The cold spots where they hibernate, we're not going to change. Those will still stay the same. We're talking about giving them additional warm spots that aren't affecting their hibernation temperatures.

FLATOW: Are we pretty sure or closing in on the idea that it's the fungus that is the cause and not just - it's an opportunistic infection?

Mr. BOYLES: It really looks like the smoking gun, but we can't say that. There are some experiments going on right now, David Blehert and his group at the National Wildlife Health Center are doing these experiments, and hopefully they'll have any for us at the end of the hibernation season. We'll know one way or the other.

FLATOW: He was on our program in October.

Mr. BOYLES: Sure.

FLATOW: Here's the question for you, if that's true, from Candis Looming(ph) in Second Life who says: Why don't you spray the cave with a fungicide?

Mr. BOYLES: This has actually come up a lot. There has been some talk about it, like I said, but it's probably logistically difficult. In some of these caves we're talking about and mines we're talking about are huge. They're massive. And I've been in a few of them, and it's hard to explain how large these things are. So that would be difficult, not to mention that in natural environments - and especially in the caves -there are lots of other things in there that we don't want to kill. You know, there are lots of natural cave species that a fungicide would be very bad for.

FLATOW: Mm-hmm. And how many bats are in some of these caves?

Mr. BOYLES: Well, not as many anymore, and I - right off the top of my head, I don't know the numbers. There were many of those that were many, many, tens of thousands in some of these sites to begin with.

FLATOW: Mm-hmm. And so what's your next step?

Mr. BOYLES: Well, the next step for us personally, for my co-author and I, is to test this. Like I said, we're going to try this get out in this cave in Manitoba shortly. We will see, at least this year, if they will use these, if the bats can actually learn to move to these sites. So that's the goal. If we find out over the summer that this stuff can't be transmitted during the summer, there's, you know, possibilities of testing this in different ways next winter, then.

FLATOW: We're talking about bats this hour on SCIENCE FRIDAY from NPR News. I'm Ira Flatow with Justin Boyles. This has very - you know, this has gained traction, has it not, this topic? You started out with no one really knew anything much about it, and it's sort of spread an interest.

BOYLES: With white nose in general?


BOYLES: It has. The research group is growing immensely. So, more and more scientists and agency folks are coming on board. There are people, at this point, all over the world that are offering their expertise to try to figure out what this is. So it's getting of traction. It's true.

FLATOW: Well, good luck to you, Justin.

BOYLES: All right. Thank you very much.

FLATOW: You're welcome. Justin Boyles is a graduate student at the Center for North American Bat Research and Conservation. That's at Indiana State University in Terre Haute.

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