I found the full article about the research, here are some snipits

NEW YORK - They wouldn’t blow away the competition on “Dancing with the Stars,” but it turns out that some birds got rhythm. ... The results support a theory for why the human brain is wired for dancing.
The verdict: Some parrots did, and maybe an occasional elephant. But researchers found no evidence of that for dogs and cats, despite long exposure to people and music, nor for chimps, our closest living relatives.

Why? The truly boppin’ animals shared with people some ability to mimic sounds they hear, the researchers say. (Even elephants can do that). The brain circuitry for that ability lets people learn to talk, and evidently also to dance or tap their toes to music, suggests Aniruddh Patel of The Neurosciences Institute in San Diego. He proposed the music connection in 2006.
So he collaborated with Snowball’s owner in Indiana for a more formal test. That showed Snowball wasn’t just mimicking the movements of somebody off-camera. And Snowball’s movements followed the beat of his favorite Backstreet Boys song, “Everybody (Backstreet’s Back)” even when researchers sped up the tune and slowed it down.

Actually, Snowball drifted in and out of following the beat, just as a child does, Patel said. But statistical analysis of his head bobs showed they really were related to the tempo.
http://www.msnbc.msn.com/id/30499458/