In superb fairywrens, all individuals learn to sing complex melodies. — Photo: pen_ash / Unsplash, via ETX Daily Up
Just like us, birds have their own character. Some are bold, others more aggressive, while some are extremely cautious. What is surprising is that their personality is reflected in their song. This is what a study conducted by Australian researchers has revealed.
For birds, singing is much more than just a pretty melody: it is used to attract a partner, to mark out territory, or even to assert their presence.
While it was previously established that certain birdsongs can reflect certain characteristics of an individual, the link between "personality" and complexity of birdsong has been little explored. And even less when it comes to females.
To fill this gap, researchers at Flinders University in Adelaide, Australia looked at the superb fairy-wren (Malurus cyaneus), a small Australasian passerine with flamboyant colors. In this species, all individuals – males, females, young and adults – learn to sing complex melodies, composed of many types of elements and syllables.
But how does the personality of each bird shape its song? To find out, scientists captured several superb fairywrens in order to evaluate two key behavioral traits: exploratory behavior (using a test in an unfamiliar environment) and aggressiveness (measured using a mirror test).
These birds were then released back into the wild and observed for several months. Their songs were recorded and carefully analyzed.
It turns out that the more adventurous fairy-wrens produce richer and more varied songs, regardless of their sex or age.
"(This) may be explained by the possibility that more exploratory birds approach and learn from a wider variety of tutors compared to less exploratory birds,” explains Dr. Diane Colombelli-Négrel, senior lecturer at BirdLab at Flinders University and co-author of the study, in a press release.
Singing is much more than simple chirping
Another surprise: the most aggressive birds sing in a simpler way, a phenomenon even more marked in juveniles. While one might expect increased complexity in the dominant birds, the opposite effect is produced.
This study, published in the journal Royal Society Open Science, sheds light on a little-known aspect of birdsong: its direct link to personality. A determining factor in seducing a mate or defending territory. Our study supports the idea that both male and female birds can advertise their personality when singing, which may be important for mate choice.
"Our results support the idea that birds, both male and female, can reveal their temperament through their song. The latter could even become a criterion of choice in the selection of a partner,” emphasizes Dr. Colombelli-Négrel.
Behind the aerial acrobatics and the feathered flight, each bird shapes a real sound ID: a unique vocal signature that reflects its way of being in the world.
The song of birds goes beyond the simple framework of melody. It results from a complex alchemy between social learning, brain plasticity, adaptation to the environment... and even dream activity!
That's right, a study coming out of Argentina, published in 2024 in the journal Chaos, revealed a fascinating phenomenon: some birds also "sing” in their sleep. By recording the micro-contractions of the syrinx – the vocal organ of birds – during sleep, the researchers were able to reconstruct the silent melodies emitted in dreams.
In short, the neural circuits of song remain active at night, as if the birds were rehearsing their concerts in their dreams. This is an unprecedented discovery among vertebrates, which is now captivating neuroscientists, ethologists and ecologists.
These singularities of the animal world offer an unsettling reflection of our own language and open an unprecedented window onto the richness of sound interactions in nature. – AFP Relaxnews
