MELISSA BLOCK, HOST:
To the Netherlands now where something has traumatized a large group of baboons at a zoo. Last week, the normally gregarious troupe of 112 baboons at the Emmen Zoo suddenly stopped eating. They sat motionless and turned their backs on zoo visitors.
Wijbren Landman is a biologist and a spokesman at the Emmen Zoo. He said the first sign that something was wrong came at night when the baboons are supposed to head indoors.
WIJBREN LANDMAN: In our zoo, all the animals are in night enclosures, and the baboons would normally go to that night and closure without any problem. And we open the door, and within 30 seconds, 112 balloons are inside. But that evening, it took us about one hour to get them inside. So there was certainly something strange going on.
BLOCK: And were they vocalizing in any way?
LANDMAN: No. It was rather silent, which is not normal for a baboon. They - it is a very social group, and they are constantly communicating with each other. And, well, they didn't.
BLOCK: And at some point, as we say, they turned their backs on zoo visitors, which I would say might be a completely understandable behavior, but I guess would be a little unusual, right?
LANDMAN: Yes. That is not what they normally do. Normally, let's say, a baboon mother carrying a just-born baby has her back between the baby and the visitors. But they did it all, and that is not normal.
BLOCK: Well, are there any explanations for what caused this trauma or this panic among the baboons?
LANDMAN: Well, we had almost 300 explanations of all different kinds.
BLOCK: What were some of those ideas that you did field?
LANDMAN: Well, we had some suggestions about real bad weather we had on Sunday with extremely many lightnings and thunders. Some suggestions were earthquakes, escaped snakes, big predators. Well, we are near in the city center, so there are no big predators coming here. We even had the reason that there were aliens or unidentified flying objects coming on so - but we didn't see them, so maybe the baboons saw them.
BLOCK: Mm. So nothing that makes sense.
LANDMAN: No. No.
BLOCK: Well, this has happened before, is that right...
BLOCK: ...among the baboon population at the zoo, that they've shown this behavior before.
LANDMAN: Yes, they did this in 1994, in '97, and in 2007.
BLOCK: Well, Mr. Landman, how are the baboons doing now? Are they back to normal?
LANDMAN: Yes. The whole strange behavior took about a week. And at this moment, we don't see any strange behavior anymore. Now, they are strolling around in harem groups, which is normal by baboons. A male with, you know, depending on his social position, he has two to six females around him, and they are grooming each other within a harem. Males fight for their social position. Young baboons are punished for being disobedient. They mate, which is a very important behavior in baboons. So they are back to normal.
BLOCK: Oh, so the mystery remains.
LANDMAN: It's still a mystery, yes.
BLOCK: Well, Mr. Landman, thanks for talking to us about it. And glad to hear the baboons are - seem to be happier now.
LANDMAN: Thank you.
BLOCK: That's Wijbren Landman. He's a biologist and spokesman at the Emmen Zoo in the Netherlands. What's the word for baboon in Dutch, by the way?
BLOCK: Baviaan? Baviaan?
LANDMAN: Yeah, baviaan.
BLOCK: Baviaan. I learned a bit of Dutch today.
LANDMAN: It's a good word to know in the (unintelligible).
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