Why It Might Not Be A Good Idea To Wipe Out Vampire Bats

Jun 6, 2017
Originally published on June 9, 2017 1:56 pm

The overwhelming majority of bats are friends of humanity. They gobble up the insects that bite us and ruin our crops. They pollinate flowers and they replant forests by spreading seeds around. But as agriculture overtakes rain forests and jungles, humans have come into conflict with one bat species: the common vampire bat.

In Latin America, vampire bats drink the blood of livestock. Very rarely, these bats contract rabies. Before they die, they can spread the deadly virus to pigs, chickens, cows — and even humans. The disease costs farmers in Latin America $30 million every year and kills dozens of people. In March of this year, a man in Brazil reportedly died of rabies after being bitten by a vampire bat.

Ranchers, whose livelihoods are threatened, want the government to wipe out this threat. But is extermination the best course of action? Would the world be better without vampire bats? Is there anything that makes them worth saving?

NPR's science YouTube channel Skunk Bear is all about tackling tricky questions. So we headed down to Panama to try and better understand the problem and this seemingly sinister species.

In a winding limestone cavern, we encountered wild vampire bats. They have amazing powers — not just razor-sharp fangs, but a nose with infrared heat sensors that can detect the warmth of flowing blood beneath the skin. They don't just fly, they use their wings to execute an awkward but effective gallop on the ground.

In the small town just outside the mouth of the bat cave, we met the people and animals they prey upon.

And in a shed on the campus of the Smithsonian Tropical Research Institute, we saw another side of the bats. Scientist Gerry Carter has spent years documenting how they treat each other in a very human way — hugs are a big thing. These little monsters regularly save the lives of their friends by sharing food.

Watch our video to learn more about this surprising species. And submit your own science questions to Skunk Bear here.

Copyright 2017 NPR. To see more, visit http://www.npr.org/.

ROBERT SIEGEL, HOST:

Bats give a lot of people the creeps, even though most bats are harmless. And they do important work like eating mosquitoes and pollinating flowers. But there is one species that does cause problems - the vampire bat. And, yes, it has earned its name because it drinks blood. NPR's Adam Cole is just back from Panama, where some ranchers want to wipe these animals out. Adam got to know vampire bats better - the good, the bad and I'd say, Adam, that the ugly includes all of them as far as I'm concerned. I imagine that some of this will get a little disgusting.

ADAM COLE, BYLINE: That's right. It will get a little bloody, at least.

SIEGEL: You got to spend some time with these vampire bats. And I saw some of the video that you made. I want you to describe what the vampire bats look like and what their unique features are.

COLE: Well, they're ugly little animals. They're a lot like other bats, but they have all these superpowers that help them find and drink blood. They've got these wrinkly noses that have infrared heat sensors so they can detect warm blood flowing beneath the skin. They've got ears that can pick up the sound of low frequencies. That's the sound of big animals breathing. And they have super sharp teeth. So when you're bitten by one of these bats, you don't even feel it.

SIEGEL: They're rodents, aren't they? Are they flying rodents? Or...

COLE: They're actually not. They're...

SIEGEL: They're marsupials or - what are they?

COLE: They're actually - the closest relative to them is the camel. So we're much more closely related to mice than bats are, as it turns out. But they do look kind of like flying hamsters or something.

SIEGEL: Flying mice is what they always...

COLE: Yeah. That's right.

SIEGEL: ...Got the bad rap of being, just flying mice.

COLE: That's right. And that's one of the many misconceptions.

SIEGEL: They also have amazing skills when it comes to mobility. They can fly, but they can also run with their wings.

COLE: That's right. They push off with their folded-up wings kind of like a - it looks like a gorilla running or something like that.

SIEGEL: How and when do vampire bats cross paths with humans? Are they in the U.S., for example?

COLE: No. They're mostly found in Latin America. That's why we had to go down to Panama to see them. And they mainly interact with humans who are raising livestock. So they'll drink the blood of cows and pigs and chickens. I visited this little town where I met a lot of cowboys who are struggling to get by. And they showed me their newborn cows with bites from vampire bats, chicken coops that were covered in drips of blood. And one rancher actually told us about how his grandchildren would regularly wake up with vampire bat bites on their feet.

SIEGEL: The bats - you're saying they come in and they bite people at night.

COLE: That's right. And that might give you the heebie-jeebies, but actually, the bites aren't that big of a health problem. The main problem is that very rarely these bats are sick with rabies. And they can spread this fatal disease to cattle and people.

SIEGEL: So the ranchers you met in Panama want their government to get rid of the vampire bats. Is there an argument for keeping the vampire bats around?

COLE: Well, I did talk to someone who made a case for the vampire bats, Gerry Carter. He's a scientist at the Smithsonian Tropical Research Institute in Panama. And he keeps a colony of the vampire bats in this big shed. Gerry does these experiments where he keeps one of the bats away from food for a night. And that's something that actually happens in the wild all the time. The bat will go out and it can't find prey. And if that happens two nights in a row, the bat could actually starve to death.

But what happens is another bat will come in and they'll rescue that hungry bat. They'll burp up a little blood to feed it. And this behavior is seen between mothers and their children and between siblings. But surprisingly, it's also seen between bats that aren't related at all. Here's a piece of tape from Gerry Carter.

GERALD CARTER: They have something that's like human friendship. They're interested in each other. They sort of, you know, are snuggling and sniffing and grooming each other all the time. I think if people knew all the things that I know about vampire bats, you would look at them differently as beautiful, intelligent animals.

COLE: And the thing is as humans keep pushing into the wilderness, we're just going to keep running into this same kind of dilemma.

SIEGEL: And would you admit to being have won over to their camp in this brush you had with vampire bats?

COLE: Well, I still have a little trouble looking at them, but I can see their value.

SIEGEL: It's the ugly thing again.

COLE: Yeah, it really is hard to get past.

SIEGEL: That NPR's science reporter, Adam Cole. Thanks for spending time with the vampire bats so that we didn't have to.

COLE: It's my pleasure.

SIEGEL: You can get to know vampire bats better, perhaps come to love them as well. You can head over to NPR's science YouTube channel, Skunk Bear, to watch Adam's latest video. Transcript provided by NPR, Copyright NPR.