Humans respond to a rhythmic beat. While most animals do not, there are some, we’re learning, that do. In The Musical Animal, a documentary from The Nature of Things, we meet researchers, scientists and musicologists who share their findings in this relatively new field that studies which species are affected by and respond to music.
Here are six things they’ve learned:
A cockatoo that can keep time
For nearly 15 years, Snowball, a male sulphur-crested cockatoo, has been an online celebrity due to his incredible dance moves. His ability to hear music and synchronize his movements to a beat has made him a star.
Aniruddh Patel, a cognitive neuroscientist at Tufts University, wanted to know more about Snowball’s moves, and conducted an experiment. He took one of the bird’s favourite songs and played it back to him at different speeds, looking to see if Snowball would move to different tempos. Not only was Snowball able to move in sync with music played at different speeds, he displayed no fewer than 14 distinctive dance moves while bopping to the music. And it seems like he’s dancing because he just loves to bust a move!
Chimpanzees sway to the rhythm
At the Kyoto University Primate Research Institute in Japan, primatologist Yuko Hattori studies chimpanzees. Through a series of experiments, she’s found that they have a tendency to spontaneously move in response to auditory rhythms. “They swayed rhythmically and also displayed a variety of kinds of rhythmic movement, like clapping, bobbing heads and foot tapping,” said Hattori.
One male chimpanzee, Akira, would sway in response to a beat. So when he heard a fast tempo, he would sway faster than when he heard a slower tempo. Even though Akira did not synchronize his swaying, his ability to alter his movements in relation to tempo changes is significant. According to Hattori, the experiments found that chimpanzees exhibited “several different aspects from human response to auditory beats,” as well as some aspects that were similar.
Harbour seal pups adjust their calls to be heard
Harbour seals belong to a family known as pinnipeds — one of the few mammalian groups capable of vocal learning. At the Max Planck Institute for Psycholinguistics in the Netherlands, cognitive biologist Andrea Ravignani has been studying the vocalization of harbour seals.
Around four hundred seals are rehabilitated annually at Sealcentre Pieterburen, on the country’s north coast, before being returned to the wild. This gives Ravignani’s team a rare opportunity to study wild harbour seal pups in a controlled environment.
When playing back seal pup calls to the study’s pup — a one-month-old female — in rhythmic intervals, she responded vocally. Instead of synchronizing with the sounds she was hearing, however, the pup would desynchronize. “The seal we were testing started making calls at a very specific point in time when there was silence,” Ravignani explained. This suggests that pups learn to adjust their own calls to fit in between those of other pups, he said. That way, they can be heard over the din of a seal colony, perhaps so their mother can find them.
Zebra finches teach their young songs like nursery rhymes
At McGill University, neuroscientist Jon Sakata has been looking at whether there are shared biological roots between birdsong and human speech or music.
Studying the vocal patterns of the zebra finch, Sakata discovered young males learn their species’ own songs the same way humans learn to speak: they listen to adults around them and mimic the sounds they hear. Young finches will practice repeatedly until they have pinned down the song accurately.
This takes a lot of hard work. As each young male tries to learn his own song, he keeps attempting to mimic the adult male’s sounds, over and over until he gets it right. It takes about 90 days, Sakata said, but once the young songbird masters his performance, the newly learned song is his for the rest of his life.
Humpback whales create song patterns and repeat them for hours
The patterns of sound that can be heard in whale song seem to have precise rhythms, according to Alex South, a bass clarinetist, who is carrying out doctoral research at the Royal Conservatoire of Scotland on humpback whale songs.
“You’ll have a stretch of humpback song where each phrase, which lasts 10 or 20 seconds, will be repeated for up to a few minutes,” South said. At that point, the whale will switch to a new theme, which could be strikingly different from the previous theme. Once it groups together several different themes, it will go back to the start and repeat them — for a long time. According to South, whales have been documented repeating the same song for as long as 22 hours.
And each song is not created by a single whale. “All the male whales in a particular population are singing the same song,” South said. “They are singing the same themes in the same sequence and using the same song units and phrases. This tells us the whales are listening to each other and learning from each other. And this is actually very rare amongst mammals.”
Can a dog adjust its pitch when it howls the way humans can?
When humans sing in a group, we tend to align our voices with others so we meet the same pitch and don’t sound terrible.
When wolves howl, they produce long, pitched vocalizations, and it’s thought, Patel said, that they are actually listening and adjusting the pitch of their howls to each other’s. Amazingly, they may also be “detuning” from each other, so they sound like a larger pack.
For a current study, Patel is asking dog owners to record their pets howling to any song that sets them off. By shifting the music’s pitch up or down and playing it back for the dogs, Patel’s team can measure their howling response to determine if they’ve changed their pitches to match.
“If they do [adjust their pitch], that suggests they are not just unleashing some innate behaviour, they are listening and adjusting their voice pitch in response to other pitches happening at the same time,” saidys Patel. “Which is the first step toward what we do when we sing.”
Watch The Musical Animal on The Nature of Things.