Snowball fight

Snowball is probably the worlds most famous living parrot,with a Wikipedia entry to prove it. One clip of him on YouTube,a video-sharing website,has had over 2m hits....

Snowball is probably the worlds most famous living parrot,with a Wikipedia entry to prove it. One clip of him on YouTube,a video-sharing website,has had over 2m hits. The sulphur-crested cockatoos claim to stardom is his ability to perform what looks decidedly like dancing to the Backstreet Boys hit,Everybody. It is an intriguing display but an aberrant one,as parrots have never been seen to dance in the wild. Nevertheless it may,according to Aniruddh Patel of the Neurosciences Institute in San Diego,shed light on the evolutionary origins of song and dance in people,too.

There are three main theories of the origins of singing and dancing. Two suggest they are functional 8211; either serving to attract mates or fostering social cohesion and thus collaboration. The third,put forward recently by Dr Patel,says the whole thing is a glorious accident 8211; the by-product of an evolved capacity for mimicking vocal cues,which humans have because that is how they learn to speak. This is a plausible explanation of singing,but how it might then lead to dancing ie,a rhythmic movement of various parts of the body in time to the music is obscure. Nevertheless,one possible test of Dr Patels hypothesis is to see if anything resembling dancing emerges in animals known to be vocal mimics,who are exposed to the rhythms of human music.

Dr Patel and his team have thus taken a close interest in Snowball,who has been residing at the Bird Lovers Only Rescue Service in Schererville,Indiana,since he was left there by his previous owners in 2007,along with a CD of his favourite music. The results of their research have just been published in Current Biology.

Their conclusion,after sophisticated statistical analysis to exclude the possibility of coincidence,is that Snowball really is dancing. If a songs tempo is changed without changing its pitch,his head-bobbing and leg-lifting change time to match. And they are not alone in this conclusion. Adena Schachner of Harvard University and her colleagues have also been studying this psittacine prodigy and they,too,have just published their findings in Current Biology.

Broadly,they endorse Dr Patels conclusion that Snowball is jiving to the beat. They have also found a similarly talented African grey parrot,and conducted the same experiments on that. But they went further than Dr Patel by trying to persuade cotton-top tamarins,a species of monkey,to learn to dance as well. They failed,as Dr Patels theory predicted they would,because tamarins 8211; although very vocal 8211; are not mimics.

Further investigation on YouTube,by Dr Schachner,has turned up 33 video clips of animals with Snowball-like talents. All told,there are 14 types of parrot in these video clips,all species well-known for vocal mimicry,and one elephant. That elephants are vocal mimics is less widely known,but it has recently been established scientifically.

Whether any of this truly endorses Dr Patels hypothesis is moot. Since none of the species looked at is known to dance in the wild,and all are known vocal mimics,it does suggest that vocal mimicry somehow provokes dance-like behaviour when an individual is exposed to a rhythmic sound. But,though there is no disputing Snowballs talent,that is not proof.

The Economist Newspaper Limited 2009