It used to be thought that dancing was unique to humans. But two separate studies have now shown that parrots have the ability to bob their heads and tap their feet to a number of different beats. One of the birds studied even has a favorite song ("Everybody" by the Backstreet Boys.)
The scientists theorized that the ability to dance evolved as a by-product in animals that are capable of complex vocal learning -- the process of converting a sound that they have heard into a behavior aimed at reproducing that sound. This process requires a tight integration of motor and auditory circuits in the brain.
Only a handful of animals are vocal learners, including humans, parrots, dolphins, elephants and seals.
The ultimate goal of the studies is to get a better understanding of the brain mechanisms behind dancing, which may have practical applications in understanding movement disorders like Parkinson's.