Birds bust a move to musical beats: studies suggest vocal mimics have a flair for moving in time.

Don't begrudge Snowball his hankering for boybands. The sulfur-crested cockatoo with a spiky haircut bobs his head, sways his body and stomps his feet in time to the beat of pop songs such as the Backstreet Boys' "Everybody."

Two new studies, published online April 30 and slated to appear in Current Biology, indicate that he and other parrots can synchronize rhythmic movements to musical beats. Until now, most researchers thought that only people align physical movements to timed sounds, a phenomenon known as entrainment.

"This is the first evidence that there could be an animal model of rhythm perception in music," says neuroscientist Aniruddh Patel of the Neurosciences Institute in San Diego, who directed one of the new investigations.

Patel proposes that brain circuitry for vocal learning gets co-opted to support musical-beat perception and synchronized movements to music: Animals that can imitate sounds can also move in rime to a beat, but animals that can't imitate sounds can't keep the beat.

Music's origins remain a mystery. Some regard music as a pleasurable by-product of other mental skills, such as language. Others suspect music arose as an evolutionary adaptation to Stone Age life, perhaps to promote social cohesion.

"Even if entrainment emerged as a by-product of vocal mimicry, other parts of music perception and cognition may easily be adaptive," says Harvard University's Adena Schachner, a psychology graduate student who directed the other new study.

Evidence of what amounts to a kind of dancing to music by at least some parrot species "comes as a big surprise," remarks W. Tecumseh Fitch of the University of St. Andrews in Fife, Scotland.

In experiments conducted by Patel and his team, Snowball listened to "Everybody." As the music sped up or slowed down across a range of tempos on different trials, Snowball frequently adjusted his dancing to stay synchronized to the beat, Patel says.

Schachner's group played familiar and unfamiliar musical pieces to Snowball, to an African gray parrot named Alex (before his death in 2007) and to 50 human volunteers. The birds synchronized their movements about as well as volunteers tapped a button. The researchers then analyzed thousands of YouTube videos showing hundreds of animal species moving to music. Signs of entrainment to a beat appeared only in vocal mimics, represented by 14 parrot species and Asian elephants that moved their trunks or legs in time with music.

Patel suspects that, as with people, some parrots have rhythm to spare and others can't pick up a beat with a forklift. Snowball's dancing, it seems, has more in common with boy band *NSYNC.