Decoding The Hyena's Laugh

LINDA WERTHEIMER, host:

Welcome back to ALL THINGS CONSIDERED. I'm Linda Wertheimer.

Now, even if you've never heard a laughing hyena in the wild, you might recognize this hyena.

(Soundbite of movie, "The Lion King")

(Soundbite of hyena laughing)

Mr. CHEECH MARIN (Actor): (as Banzai) It's not funny, Ed.

(Soundbite of hyena laughing)

WERTHEIMER: That is Ed, the hyena from Disney's "Lion King." Well, the real hyena laugh actually sounds a lot like that.

(Soundbite of hyena laughing)

WERTHEIMER: And new research from the University of California in Berkeley suggests that the hyena's giggle is really as expressive as it sounds. The hyena is telling us who she is, how old she is.

Frederic Theunissen is one of the researchers who studied the hyena's laugh. He joins us from Berkeley.

Welcome.

Professor FREDERIC THEUNISSEN (Psychology, University of California, Berkeley): Thank you.

WERTHEIMER: So, where do you find hyenas to study in Berkeley?

Prof. THEUNISSEN: We have a very special situation here on the Berkeley campus. We have a colony of captive hyenas that were brought on the Berkeley campus in 1985. They don't live really on campus but up in the Berkeley hills.

WERTHEIMER: Are they what we used to call, when I was a kid, laughing hyenas?

Prof. THEUNISSEN: Correct, yeah. So this is a colony of spotted hyenas and the spotted hyena is the laughing hyena. It's actually the only hyena among the three living hyenas that produces the giggle sound or the laugh.

WERTHEIMER: How do you get hyenas to make these noises?

Prof. THEUNISSEN: Yes, so this is a noise that the hyenas make when they want something they don't really have access to it. So, it's a call of frustration with, you know, some amount of tension. So, in the field, these calls often happen at kills where there's competition for food and where there's going to be some dominant hyenas, let's say, displacing subordinate hyenas, in which case, the subordinate hyenas will giggle.

And we tried to reproduce a very similar situation with our captive hyenas by showing them a nice piece of meat that they really want but denying access to this meat.

WERTHEIMER: And what do you learn from that?

Prof. THEUNISSEN: So, each hyena has its own individual giggle or laugh, just like in humans, we each have our own voice. But what did kind of struck me in terms of the individual recognition is that if you took just a single giggle note, so you heard the succession heh, heh, heh, heh, heh; just take one of those heh, there's enough information to basically get some information about the identity of the animal.

WERTHEIMER: One of the sounds you sent us is something that you call a slow woo.

(Soundbite of hyena)

WERTHEIMER: Professor Theunissen, I have to say that that is a very scary noise. That's not anything like that little giggly thing. Why do they make that noise?

Prof. THEUNISSEN: This is their contact call. So, they produce this sound when, you know, they have been kind of isolated from the rest of the pack and they want to touch bases again with the rest of the group. It's a call to other hyenas that doesn't quite have the urgency of the giggle in terms of, you know, come here now. It's more of, you know, this is where I am and where are you.

WERTHEIMER: You also sent us something you call a groan. Let's listen to that.

(Soundbite of hyena)

WERTHEIMER: These animals have such a lot of range. I mean, there's that little high-pitched giggly thing and then these incredibly deep, dark groans.

Prof. THEUNISSEN: This rhythmic groan is something that they make in meeting ceremonies. So, this is a softer sound that they make when they're meeting again after a time when they were separated. It sounds kind of, you know, low and scary to us, but I think it's not the case for the hyenas.

WERTHEIMER: Now, you're a professor of psychology, Professor Theunissen. Could it be that you're anthropomorphizing these noises? You're assigning human qualities to them?

Prof. THEUNISSEN: I'm kind of describing kind of my emotional responses to these sounds. And, you're right, we have to be very careful about not projecting that. You know, the fact that there is information about status, let's say, in the giggle, and that status is so important for this animal, I think, you know, it wouldn't be going on a limb saying, okay, the information is there to be used by other hyenas, because this is such an important thing for them to do.

WERTHEIMER: Uh-huh. Well, now, to continue in the vein of anthropomorphizing, did you find that you liked them?

Prof. THEUNISSEN: Oh, absolutely. I think any researcher who starts working with these animals falls in love with them. They're unusual and they're smart and they're interested in you and very interested in each other. It's just remarkable to see them interact.

WERTHEIMER: Frederic Theunissen is a professor of psychology at UC Berkeley. His paper on the meaning of the hyena's giggle was just published in the open access journal BMC Ecology.

Professor Theunissen, thank you very much for being with us.

Prof. THEUNISSEN: Thank you, Linda. It was my pleasure to be here. Transcript provided by NPR, Copyright NPR.