People aren't the only ones who've got rhythm. Two recent reports published in Current Biology, an online Cell Press publication, reveal that birds, and parrots in particular, can also bob their heads, tap their feet, and sway their bodies along to a musical beat.

The findings show that a basic aspect of the human response to music is shared with other species, according to the researchers.

"We've discovered a cockatoo [named Snowball] that dances to the beat of human music," said Aniruddh Patel of the Neurosciences Institute in San Diego, lead author of one of the studies. "Using a controlled experiment, we've shown that if the music speeds up or slows down across a wide range, he adjusts the tempo of his dancing to stay synchronized to the beat."

One of Snowball's favorite dancing tunes is none other than the Backstreet Boys' "Everybody."

"For a long time, people have thought that the ability to move to a beat was unique to humans," added Adena Schachner of Harvard University, who led the other study.

"After all, there is no convincing evidence that our closest relatives, chimpanzees and other apes, can keep a beat, and there is similarly no evidence that our pet dogs and cats can line up their actions with a musical beat, in spite of extensive experience with humans. In this work, however, we found that entrainment [to music] is not uniquely human; we find strong evidence for it in birds, specifically in parrots."

Before this discovery, "scientists who studied music and the brain thought that moving to a musical beat might be a uniquely human ability because we don't commonly see other animals moving rhythmically to music," Patel agreed.

In fact, as far as they know, birds in the wild don't move in time with sounds, leaving many scientists to think that this ability might be an evolutionary specialization of the human brain for music cognition.

But that may not be so, the new studies suggest. They now suspect that the parrots' ability can be traced to another capacity they share with people: vocal learning or mimicry.

Indeed, Schachner's group searched YouTube for videos of dancing animals. Of more than 1,000 videos that turned up, only those of vocal mimics, representing 14 parrot species and one species of elephant, showed evidence that they could really get into the groove. That result is in keeping with the notion, first proposed by Patel, that entrainment to a musical beat relies on the neural circuitry for complex vocal learning, which requires a tight link between auditory and motor circuits in the brain, they said.

"A natural question about these results is whether they generalize to other parrots, or more broadly, to other vocal-learning species," including songbirds, dolphins, elephants, and pinnipeds, a group including walruses and seals, Patel said.

The findings in birds also offer new insight into humans' relationship to music.

"Why humans produce and enjoy music is an evolutionary puzzle," Schachner's team wrote. "Although many theories have been proposed, little empirical evidence speaks to the issue. In particular, debate continues over the idea that the human music capacity was not selected for directly, but arose as the byproduct of other cognitive mechanisms."

"By supporting the idea that entrainment emerged as a byproduct of vocal mimicry in avian species, the current findings lend plausibility to the idea that the human entrainment capacity evolved as a byproduct of our capacity for vocal mimicry."

Professor John Hildebrand, a blue whale expert at Scripps Institution of Oceanography at UCSD, has studied recordings of whales “singing” since the 1960s. He says the whales’ rhythmic underwater moaning, which often sounds musical, is becoming lower and deeper.

“This is giving us an insight into the culture of blue whales, as they are clearly listening to each other’s songs and changing them,” he told the UK’s Sunday Telegraph. “It takes a conscious decision to make the calls deeper, so it is a reflection of what is going on in the population.”

According to Hildebrand, whale calls used to average 22Hz, whereas today the frequency is around 15Hz. “These animals have a finite lung capacity, so their songs are a trade off between frequency and volume. They can either make the song really loud, or really deep.” Most researchers think whale songs are intended to attract mates, or to communicate to others during the mating season.

The world’s largest animals, whales are enjoying a population growth, thanks to protections put in place after many species were nearly wiped out. It’s estimated that there are currently around 4,500 blue whales.

“As their numbers have slowly increased after the devastation caused by whaling,” says Hildebrand, “they are having to communicate over smaller distances. So their songs don't need to be as loud, and they can make them deeper."

Those interested in hearing songs of the blue whale can find hundreds of recordings at the UCSD Sound Library.

Professor David Rothernberg, of the New Jersey Institute of Technology, says he communicates with whales through musical instruments mic’d to hydrophones. His book Thousand Mile Song describes underwater “jam sessions” he’s enjoyed with humpback whales.

“For me,” he told telegraph.co.uk, “I felt like they could recognise the music I was making and were responding to that. There was a very special interaction with a humpback, and he seemed to change his song so that, by the end, it was hard to tell which was the clarinet and which was the whale.”

The whales apparently respect and respond to musical innovation, being enraptured by and then mimicking any Beatles-like whales among them who come up with a new tune AND a new way of “singing” and performing it.

“These are incredibly social animals, and they seem to change their songs regularly. When one of them innovates, this gets picked up by the rest of the population, and then they all start singing in the same way.”