Snowball, the dancing sulphur-crested cockatoo, is a big hit on YouTube--and now he's also a scientific sensation. Researchers have shown that the bird, who bobs his head and lifts his legs to the Backstreet Boys' song Everybody, is in fact listening to and following the beat. The findings--detailed in a pair of articles--challenge the notion that only humans have the neural wiring for dancing in time to music. "These are pathbreaking studies," says Bruno Repp, a cognitive psychologist at Haskins Laboratories in New Haven, Connecticut.
Aniruddh Patel remembers the first time he saw Snowball on the Internet. A neurobiologist at the Neurosciences Institute in San Diego, California, Patel had argued in an earlier study that our talent for moving synchronously to a rhythmic beat is tied to our ability to learn and mimic sounds. "It seems to be a byproduct of a link between the auditory and motor parts of the brain," he says. That seemed to rule out most animals except humans and parrots. Nevertheless, Patel was stunned to see Snowball's video. "My jaw hit the floor," he says.
To see if the cockatoo was actually in the groove and not simply trained, Patel visited Snowball at his Indiana home. He put the bird through the paces of a controlled experiment, speeding up and slowing down the music's tempo. Snowball wasn't fazed. "He adjusted the tempo of his dancing to stay synchronized to the beat," says Patel. To do so, he "must be monitoring the sounds" and changing his bobbing and kicking as the musical beat speeds up or slows down. The same neural abilities are required to imitate sounds, explains Patel, whose team reports its findings online today in Current Biology.
In a companion paper, another team revealed a similar talent in 14 species of parrot and in Asian elephants. This time, the star was an African gray parrot named Alex (now deceased). Although well-known for his ability to mimic sounds and English, Alex had never been tested for musical ability. When Adena Schachner, a graduate student in cognition at Harvard University, played a tune for him, the parrot began rhythmically bobbing. Like Snowball, Alex also changed his beat as the music changed.
That spurred the authors to look for other musically talented animals. They analyzed more than 1000 YouTube videos of dancing animals, including dogs, cats, chimpanzees, elephants, and birds, to see which individuals were actually moving synchronously with the beat and responding correctly if the beat changed. Only vocal mimics--primarily parrots, as well as one Asian elephant--could do so, the team discovered. (One elephant has been shown to imitate truck noises (ScienceNOW, 23 March 2005), a sign of vocal mimicry.) "It does seem that vocal mimicry and keeping a beat rely on the same neural mechanisms," says Schachner.
Now, "for the first time, we have animal models for investigating the neurobiology and evolution of human music," says Patel. But he also notes that parrots haven't been shown to dance to a beat in the wild, even to the songs of their courtship displays.
Perhaps they just need to be inspired by the Backstreet Boys.