Spotted hyenas grunt and growl. But you know what they're famous for. [Hyena sounds.] So what's all the laughing about?
Well, field researchers have noticed that groups of hyenas tend to giggle around a kill, while they're waiting for their hunk of meat. Now a study in the journal BMC Ecology [See http://bit.ly/cGTzkn] says the chuckles may communicate things like age, identity and social status. Which is important stuff for figuring out who gets the tastiest cut of zebra.
Researchers [Nicolas Mathevon et al.] studied a clan of spotted hyenas living in a sanctuary behind the U.C. Berkeley campus. They enticed 17 hungry hyenas with bones or pieces of meat, and recorded about 250 bouts of giggling. Then they ran those sound bites through various computer algorithms, running statistical analyses and drawing up spectrograms.
The result? They say a giggle's pitch and timbre establish a hyena's identity, and that pitch indicates age. But the giggle also tells you who's boss. A relatively monotone giggle [hyena sound] and you're first to the meat. A more erratic, variable giggle? [Hyena sound] Get back in line.
The researchers next plan to study hyenas in the wild. Just for laughs.
[The above text is an exact transcript of this podcast, which is not an April Fool's joke, despite all the giggling.]