SCIENCE LAB SCENES : GIBBON GYRATIONS

It's not tweaking, salsa or breaking. Maybe it's somewhere between voguing and the robot. Whatever you call it, the performance style of a female gibbon is a dance, researchers say.

Kai Caspar, a zoologist in Germany, and colleagues analyzed the stylized movements of gibbons. They found that key characteristics of human dance are also present in the gibbons' moves.

Dr. Caspar became interested in the dancing of gibbons when he was trying to learn how gibbons in zoos respond to mirrors.

The apes didn't recognize their reflections, but they did show off their moves. Earlier research had described dances by four wild gibbons in China.

To study dances in more gibbon species, Dr. Caspar teamed up with Camille Coye, a primatologist in Paris, and Pritty Patel-Grosz, a linguistics professor at the University of Oslo.

They defined dance as an intentional movement that's rhythmic and doesn't serve a physical purpose, like walking or scratching an itch does.

They surveyed people who worked with crested gibbons about whether they had seen the animals dancing and analyzed videos from zoos.

All the ape dancers were adult females, and usually performed with their backs to the viewers. The apes swayed, dipped and posed bizarrely. Often an ape looked over her shoulder to make sure her viewer was watching. [ Elizabeth Preston ]