There are hints our closest relatives may have some inkling of making musical percussion. Wild chimpanzees drum their feet on the buttress roots of trees to communicate over long distances, while a captive bonobo was able to hand-drum in time with a human experimenter. But the closest thing the animal kingdom has to a cymbal-bashing rock drummer is Australia’s palm cockatoo.
These smoke-grey birds are a dramatic sight: reaching 60 centimetres in length, they sport an expressive crest, bright red cheek patches, and a formidable, haughty bill that functions like a Swiss Army knife. Males use that curving beak to create drumsticks from sticks and seed pods, which they beat rhythmically against hollow trees during mating displays.
We know this because, for four years, University of Queensland ecologist Christina Zdenek devoted her life to the endangered cockatoos. For five months of the year, she was ensconced in their environment, camping out in Far North Queensland’s remote Cape York Peninsula. She lived in a “humpy”—two walls, a roof, no electricity, and at first, no running water.
Initially, Zdenek and her colleagues wanted to find a way to identify individual palm cockatoos without having to capture or disturb them. They thought the birds’ complex vocalisations might be unique enough to provide an auditory signature for each. But as Zdenek tracked the birds in the heat through head-high grasses, she realised the males weren’t just singing their own songs—they were also marching to the beat of their own drum.
She started trying to catch them in the act of drumming to females. On average, it took more than 100 hours of stalking for Zdenek to capture one two-and-a-half-minute drumming performance. “I’m not normally too emotional, but I would certainly shed some tears when I saw it,” she says. “It would only happen once every few weeks.”
The display unfolds like this: a male cockatoo calls to his female, bows, shows off his wingspan, erects his crest, stomps his feet, then gets to work on a drumstick. He selects a likely twig, carefully strips the leafy end and side-branches from it, snaps it from the tree with his powerful beak, then wields it with a foot. Sometimes, the cockatoo instead selects and shapes a round grevillea seed pod—Queenslanders call them “bushman’s clothes pegs” —and drums with that on the tree.
Every beak-made drumstick is unique, from short and stubby to long and tapering, and each cockatoo has his own musical approach. Some drum slowly, others quickly, and some accelerate their tempo. Musical style seems to be passed down from father to son; the birds don’t learn their rhythms from neighbouring birds, like humpback whales do their songs.
Eventually, Zdenek recorded 60 drumming events on video. From that hard-won data, she and her team were able to prove that male palm cockatoos do create a rhythmic pulse with their tapping—which makes the cockatoo the only animal known to do so. “It’s got the fundamentals of human music,” she says.
But why do they do it? Zdenek thinks the drumming displays take place mostly between cockatoo couples, helping to reinforce their bond, to coordinate breeding, and to lay claim to the rare tree hollows they use to incubate eggs.
Palm cockatoos are long-lived and mostly monogamous, tending to stay with the same partner for decades. A male’s drumming, then, might not be so much about attracting a new female as keeping the passion alive with his existing mate.