It swings in the treetops, but does that bird make music?

When a bird sings, you may think you hear music. But are the melodies it creates really music? Or is what we hear just a series of lilting calls that appeal to the human ear?

Birdsong has inspired musicians from Bob Marley to Mozart and perhaps as far back as the first hunter-gatherers to bust out a beat. And a growing body of research shows that the affinity human musicians feel for birdsong has a strong scientific basis. Scientists are understanding more about bird species’ ability to learn, interpret and produce songs much like ours.

Like humans, birds learn songs from each other and practice to perfect them. And just as human speech differs from human music, bird sounds, 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, do birds make music? That depends on what you mean.

“I’m not sure we can or want to define music,” he said Ofer Tchernichovskya zoologist and psychologist at the City University of New York who is studying bird song.

Where you draw the line between music and mere noise is arbitrary, he said Emily Doolittle, zoomusicologist and composer at the Royal Conservatoire of Scotland. The difference between a human baby’s babble and a toddler’s humming may seem more obvious than that of a boy’s cry for food and an adult bird’s practice of a melody, she added.

Wherever we draw the line, birdsong and human song have striking similarities.

How birds build songs

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 melodies that resemble our own melodies.

Other characteristics, such as cadence and tension, are also used in both birdsong and human music, he said Tina Roeske, a behavioral neurobiologist specializing in birdsong. Just like the famous tune “In the Hall of the Mountain Kinggradually builds speed on “accelerando” as composition notation is known, some birdsongs do as well, such as that of the nightingale.

While previous studies focused on syntax, or how notes were ordered, newer research also integrates rhythm by analyzing how notes are timed. In human music, rhythm is often seen as a steady beat, like the one that opensWe’ll rock youby Queen. But in birdsong, rhythm refers to note patterns, regardless of whether they are repeated.

To humans, birdsong appears to be “a random structure,” said Dr. Roeske. Because of the speed at which birds sing — up to four times faster than most human music — that rhythm is “hard for us to understand and appreciate,” she added.

Dr. Roeske and her co-author Dr. Tchernichovsky investigated the musical structure of birds and found that the rhythm of birdsong fell into three general categories. The first is isochronous, where intervals between notes are equally spaced.

Alternating, where one note is longer than the previous one.

And ornament, an exaggerated form of the alternating pattern.

Human music also contains these rhythmic patterns.

In their 2020 studycompared Dr. Roeske and Dr. Tchernikovski recordings of thrush nightingales across Europe with examples from music genres around the world, including western classical piano, Persian drumming And Tunisian stambeli. They found that birdsong and global music forms had the same types of timing components, integer ratios, that form the basis of most melodies.

In music, these ratios are the amount of time between notes. A 1-to-1 ratio means that the notes are spaced evenly, as in “Twinkle, Twinkle, Little Star”, but a 1-to-2 ratio means that the time from one note to the next is uneven, as in “Itsy Bitsy Spider,” Dr. Roeske explained.

As they charted entire proportions of birdsong and human music, the plots all produced a similar shape resembling a long-stemmed flower. This indicates that some birds build songs with patterns similar to those found in human music.

Other researchers gain insights by focusing on the rhythm of birdsong.

“We found that rhythm and syntax have a relationship that no one has thought about before,” he said Jeffrey Xinga psychology graduate student at the University of California, San Diego, and an author of a September 2022 paper analysis of the song structure of the Australian pied butcherbird.

Pied butcherbirds “seem to prefer some song rhythms over others,” such as isochronous rhythm, Mr. Xing said. In some ways, these rhythmic patterns follow rules like forms of strict meter poetry. A good example is a sonnet.

“It’s a very rigid rhythmic structure that you have to follow, and somehow the syntax of the words you use has to conform to that,” he said.

Human brain and bird brain

Holly Taylor has devoted her life’s work as a violinist and ornithologist to the pied butcher bird, a species she considers a fellow musician.

Ms. Taylor, who analyzed the bird’s rhythmic structures with Mr. Xing, records the birds’ song in the Australian deserts and savannas in the middle of the night. She then converts their notes into musical notation.

“The musician in me recognizes the musician in them,” Ms. Taylor said.

She has observed what appear to be warm-up sessions, rehearsals, and singing competitions. Other than humans, there is only a “small club” of species with a perceived ability to learn songs and voice patterns, Ms Taylor said, including songbirds, parrots, hummingbirds, bats, elephants and some marine mammals.

Ms. Taylor has performed her birdsong-esque compositions with orchestras around the world. She is inspired by the French composer Oliver Messiaenwho also transcribed birdsong into musical notation.

Musicians’ fascination with birdsong has deep roots. mozart, historians tell, kept a European starling in his apartment in Vienna for three years. In a letter to his father, Mozart remarked on the “beautiful” and precise way in which the starling learned and repeated one of his concertos.

While there is no concrete evidence that Mozart’s starling influenced his compositions, the idea persists that birds influence composers’ work.

The French composer François-Bernard Mâche, founder of zoomusicology, speculates that birds may have influenced Igor Stravinsky’s compositions during summer sojourns in what is now Ukraine. According to dr. Doolittle research, the song patterns of Eurasian blackbirds found in that region resemble Stravinsky’s style of composition.

Neuroscientific research points to the idea that this affinity between birds and humans is not all that unusual. In terms of musical ability, we are more like birds than our primate or other mammal cousins, he said Johan Bolhuisa zoologist who specializes in the cognitive neurobiology of birds and humans.

Our brains and the brains of songbirds have a similar way of learning musicality. But the brains of monkeys and non-songbirds, such as gulls, are organized differently, said Dr Bolhuis. It could be a sign of shared creative abilities: Like humans, some songbird species seem to improvise based on the song patterns they’ve learned.

For example, both humans and birds can produce great hits that evoke feelings in their listeners, explains the psychologist Dr. Tchernichovsky out.

“When you hear music, what do you feel? Well, it depends on the music,” he said.

For example, listening to a funeral march can make you sad even when you’re on vacation at the beach, and a romantic song can fill you with love even when you’re working on your taxes. Birdsong can influence the behavior of other birds by luring in a mate or scaring off an unwanted enemy, similar to how we can turn up the volume when we hear our favorite song or move to the next song when the mood is off.

“This is the magic in music,” said Dr. Tchernichovsky. “Bird songs also seem to have some of this magic.”

But there’s no evidence that their songs have meaning, Dr Bolhuis said.

“In the mind of the great composers, they really meant something” with music, he said. “It’s not so much the case with birdsong.”

Birds also have a limited repertoire, while with only a limited number of items, the human mind “can be infinitely creative,” said Dr. Bolhuis.

However, researchers agree that birdsong can convey identity. “They can recognize individuals the way you and I can recognize each other by our voices,” said Mike Webster, director of the Cornell Lab of Ornithology’s Macaulay Library.

If birds from a certain area hear a familiar bird sing, he explains, it’s not a problem. But if the same bird moves to a new area, the birds there go “bananas” in a territorial ruckus. In that sense, singing is like a way for birds to identify themselves, but there could be more to it.

Why do birds sing?

While scientists have studied birdsong for decades, they know little about why and how birds select specific tunes and what counts as intentional communication versus meaningless singing.

Through brain imaging studies, neuroscientists have discovered that the human brain responds most strongly to music along a particular neural circuit which is activated when a person listens to a song that is perceived as pleasant. Studies have shown that birdsong elicits the same response in female birds, possibly as an evolutionary mechanism for mate attraction. But scientists still wonder if birds sing for entertainment in addition to mating.

“What happens in the bird’s head when it sings? Is it happy?” said Dr. Webster. People often sing when they’re emotional — both happy and heartbroken — but scientists don’t know if birds have such an emotional range.

Dr. Webster, who studies bird behavior and communication, added another unknown: If the main purpose of birdsong in some species is for males to attract females, why do some females also sing? “Female song actually arose very early in songbird evolution,” he said. “In species where females don’t sing, it’s because they’ve lost the ability to sing rather than they’ve gained it.” This indicates that singing was once evolutionarily beneficial to women – and scientists can’t say why.

There are other mysteries. Ornithologists have observed “bird chatter” in parrots, when two birds appear to be whispering to each other. There are also non-vocal sounds, said Dr. Webster: Some birds snap their wings, some drum on trees, and others rub their feathers together as if playing the violin. The purpose of these sounds – whether communicative, musical, or both – is on the next frontier of ornithological research.

“We’ve just scratched the surface,” said Dr. Webster. “Birds make noise all the time, and I think most of the time we don’t really know why, and we don’t really know what they’re saying to each other.”