New Delhi: A new study by McGill University found that humans and birds have fundamentally similar speech and song patterns. Studying over 350 bird species and over 52 human languages, the researchers, in a paper published on 29 October, said that there are “universal” patterns of rhythm, pitch intervals and elongations in how humans and birds vocalise.
“Songbirds, hummingbirds and parrots are ‘vocal learners,’ just like humans, meaning that they learn their vocalisations by imitating others,” explained Jon Sakata, senior author of the study, in a press release.
This is the first-ever study which compares vocal patterns in all kinds of songbirds, those that learn by imitating and those that have innate songs, to both human speech and human songs, thus shedding light on the mechanisms of vocal production.
There are more than 4,000 species of songbirds in the world, which are defined as having a highly developed voice organ called the syrinx. However, certain bird species are not directly songbirds, but do have the trait of vocal learning, meaning they can listen and imitate noises and sounds from their surroundings. These include parrots, hummingbirds, and mockingbirds.
For the study, researchers from the Canadian university’s Centre for Research in Brain, Language and Music looked at four types of birds: hummingbirds, songbirds, suboscines, and nightjars.
Rather than recording bird voices manually, they used public recordings available on Xeno-Canto, a citizen science website. The researchers analysed over 70,000 units of bird song recordings for the study. Similarly, for human voices and songs, they analysed over 15,000 units across 52 languages.
Initially, the study had hypothesised that human speech and song would share similarities with vocal-learning birds such as hummingbirds. This is because they’re both learned or imitated styles. However, once they conducted the analysis, researchers did not find much evidence to support this theory.
Instead, they found that all vocalisations by bird species and human languages and songs shared some universal traits — they had short pitch intervals, they had regular and predictable rhythms, and phrase-final elongation, where the last word or phrase is said in a way that is longer than the other words.
Specifically, the study found that whether the songs were original, as many male songbirds produce, or learnt, produced by hummingbirds and parrots, they shared the same traits in common with human speech.
“For example, birds and humans are unlikely to dramatically change pitch from one note to the next (‘small pitch intervals’) because it is difficult to do. Phrase-final elongation in birds and humans could be due to breathing patterns when we vocalise,” said Logan James, first author of the study, in a press release.
The study stated that this could be used to better understand vocal production across species, not just in birds and humans. Also, given the wide variety of songbirds and vocal-learning birds globally, the study could also prompt deeper research into their behaviour.
(Edited by Insha Jalil Waziri)