High tunes: It rocks in the tree tops, but is that bird making music?

Marlowe Starling

When a bird sings, you may think you’re hearing music. But are the melodies it’s making really music? Or is what we’re hearing merely a string of lilting calls that appeals to the human ear?

Birdsong has inspired musicians from Bob Marley to Mozart and perhaps as far back as the first hunter-gatherers who banged out a beat. And a growing body of research is showing that the affinity human musicians feel toward birdsong has a strong scientific basis. Scientists are understanding more about avian species’ ability to learn, interpret and produce songs much like our own.

Just like humans, birds learn songs from each other and practice to perfect them. And just as human speech is distinct from human music, bird calls, which serve as warnings and other forms of direct communication, differ from birdsong.

While researchers are still debating the functions of birdsong, studies show that it is structurally similar to our own tunes. So, are birds making music? That depends on what you mean. “I’m not sure we can or want to define music,” said Ofer Tchernichovski, a zoologist and psychologist at the City University of New York who studies birdsong.

Where you draw the line between music and mere noise is arbitrary, said Emily Doolittle, a zoomusicologist and composer at the Royal Conservatoire of Scotland. The difference between a human baby’s babbling versus a toddler’s humming might seem more distinct than that of a hatchling’s cry for food and a maturing bird’s practicing of a melody, she added. Wherever we draw the line, birdsong and human song share striking similarities.

Existing research points to one main conclusion: Birdsong is structured like human music. Songbirds change their tempo (speed), pitch (how high or low they sing) and timbre (tone) to sing tunes that resemble our own melodies.

Other features, like cadence and tension, are also used in both birdsong and human music, said Tina Roeske, a behavioral neurobiologist who specializes in birdsong. Just as the familiar tune “In the Hall of the Mountain King” gradually builds speed “accelerando,” as the compositional notation is known, some birdsong does too, like that of the nightingale.

While earlier studies focused on syntax, or how notes were ordered, newer research is integrating rhythm, too, by analysing how notes are timed. In human music, rhythm is often thought of as a constant beat, like the one that opens “We Will Rock You” by Queen. But in birdsong, rhythm refers to patterns of notes, regardless of whether they are repeated.

To humans, birdsong may appear to have “a random structure,” Dr. Roeske said. Because of the speed at which birds sing — up to four times as fast as most human music — that rhythm is “hard for us to grasp and appreciate,” she added.

Dr. Roeske and her co-author Dr. Tchernichovski researched birds’ musical structure and found that birdsong rhythms fell into three general categories. The first is isochronous, in which intervals between notes are equidistant.

Human music contains these rhythmic patterns, too.