JUDY WOODRUFF: Finally, we stay in the Halloween spirit for our “NewsHour” Shares, something that caught our eye that we thought would be of interest to you, too.
It turns out the vampire bat is hardly the agent of evil its association with Dracula would suggest. We asked Smithsonian researcher and vampire bat expert Gerry Carter to clear up some of the myths.
GERRY CARTER: I’m Gerry Carter, and I study food-sharing relationships in vampire bats.
Vampire bats are small, neotropical bats. They weigh about 30 grams, and they drink nothing but blood. The legend of the vampire actually came first before the bat was discovered by Europeans. So, the bat is actually named after the monster, and not the other way around.
One idea about vampire bats that’s very common, especially in Latin America, is that most bats are vampire bats. And that’s certainly not true. There are only three species of vampire bats, and there are roughly 1,300 species of bats.
The common vampire bat usually feeds on mammals and livestock. The white-winged vampire bat will often climb along the underside of a branch to feed on the toes of a bird. And the hairy-legged vampire bat will actually land on a bird like a chicken and hide in the feathers. So, it’s like a giant tick.
Vampire bats have these razor-sharp teeth that they use to make a small cut, and then they lick the wound. And they have an anticoagulant in their saliva which keeps the blood flowing, and they will take about a tablespoon of blood. And if they’re successful, then the animal is none the wiser, never finds out that the bat was there until the next morning maybe.
And one of the interesting things about the biology of vampire bats is that they’re very susceptible to starvation. So they don’t put on fat, they don’t store energy, and they can starve if they miss more than two meals.
But other bats in their roosts will often regurgitate a portion of their blood meals to feed them. So, you can fast an individual, and then another individual will go and save that individual’s life, essentially.
And that’s one of the things that makes the vampire case so interesting in terms of an example of cooperation in nature. These vampire bats, they’re like these alien life forms, and yet there are so many things that they do that seem very convergent with what people do, with what primates do.
Vampire bats do things like they groom each other. They seem to have these friendship-like relationships. And yet everything else about them is so strange.
I don’t think people should be scared of vampire bats. Even within bats, I think vampire bats are probably the most hated and feared of all of the bats. But I think, the more you learn about vampire bats, the more you realize just how incredible they are.
JUDY WOODRUFF: I just saw one fly through the studio.
That’s the “NewsHour” for tonight. I’m Judy Woodruff. Join us online and again right here tomorrow evening.
For all of us at the “PBS NewsHour,” happy Halloween, and good night.
In our NewsHour Shares series, we show you things that caught our eye recently on the web. What about you? Leave your suggestions in the comments below, or tweet to @NewsHour using #NewsHourShares. We might share it on air.