Language has long been considered a uniquely human trait, with features that mark it out as distinct from the communication of all other species.

However, research published today in Science has uncovered the same statistical structure in humpback whale song that is a hallmark of human language.

Dr Jenny Allen is a leading expert in whale song structure from Griffith University’s Southern Ocean Persistent Organic Pollutants Program (SOPOPP) in the Centre for Planetary Health and Food Security.

Dr Allen worked with an international team, led by Professor Inbal Arnon of the Hebrew University, Dr Ellen Garland of the University of St Andrews, and Professor Simon Kirby of the University of Edinburgh, in collaboration with Dr Claire Garrigue (IRD New Caledonia), and Dr Emma Carroll (University of Auckland).

This work represented a unique collaboration between linguists, developmental scientists, marine biologists and behavioural ecologists.

The team applied innovative methods inspired by how babies discovered words in speech to eight years of humpback whale recordings collected in New Caledonia, uncovering the same statistical structures found in all human languages.

The findings also revealed previously undetected structures in whale song, illustrating a deep commonality between two unrelated species united by the fact their communication systems were culturally transmitted.

“Humpback whale song is culturally transmitted on a geographic scale not seen outside of humans, yet they are evolutionarily quite distinct from us," Dr Allen said.

“This is why it provides such an exciting comparison.”

“These results give us unique insight into the importance of cultural transmission in learning processes across species, particularly for learning complex systems of communication.”

“Rather than trying to fit animal communication into a ‘human language’ shaped hole, I think the more interesting question is “why did such different communication systems evolve such similarities?”

Human language, which is also culturally transmitted, has recurring parts whose frequency of use follows a particular pattern.

In humans, these properties help learning and may come about because they help language be passed from one generation to the next.

Prof Inbal Arnon from the Hebrew University said “using insights and methods from how babies learn language allowed us to discover previously undetected structure in whale song”.

“This work shows how learning and cultural transmission can shape the structure of communication systems: we may find similar statistical structure wherever complex sequential behaviour is transmitted culturally.

“It raises the intriguing possibility that humpback whales, like human babies, may learn their song by tracking transitional probabilities between sound elements, and using dips in those probabilities as a cue to segment the song.”

The study ‘Whale song shows language-like statistical structure’ has been published in Science.


From: University of Auckland 

Whale song and human language share same structure, research shows

Whale song and human language share the same structure according to a breakthrough study by an international team of marine biologists and language
experts.

The scientists analysed the groans, moans, whistles, barks, shrieks and squeaks in humpback whale song recordings collected over eight years in New Caledonia.

“We found something truly fascinating,” says Dr Emma Carroll, a marine biologist at Waipapa Taumata Rau, University of Auckland. “Their noises and our words share a common pattern.”

This doesn’t mean whales have language, but it could point to similarities in how two evolutionarily distant species’ communication systems have evolved and how they are learned.

Across human languages, the most used word appears about twice as often as the second most common word, three times as much as the third most common word and so on. This is called Zipf’s Law. The words used most frequently are very short, such as “the”, “of”, and “and”.

Dividing the whale song into segments, the researchers found the same rules of frequency and brevity apply.

In a paper published in the journal Science, the researchers argue that the structure may aid “learnability,” just as it would for humans.

The research was led by Professor Inbal Arnon of the Hebrew University in Israel who’s a specialist in language acquisition in children. The senior author was Dr Ellen Garland of the University of St Andrews in the UK, a humpback whale song expert.

Carroll, a co-author of the paper, is an expert in whale genetics who has worked with Garland on understanding the evolutionary basis of whale song.

Humpback whale song is one of the most complex acoustic displays in the animal kingdom, a striking example of a socially learned, culturally transmitted behaviour. Only performed by males, the song likely plays a role in the selection of mates.

A song can last for as long as twenty minutes and involves many sound types arranged into a pattern.

“Of course, there are many differences between whale song and human language,” the researchers write in the paper. “Most importantly, expressions in language have semantic content. The meaning of sentences is composed of the meanings of the parts and how they are put together. We make no such claim for whale song. We have little understanding of the ‘meaning’ of the songs, let alone the different units, for humpback whales.”

Once thought to be unique to humans, it may transpire that foundational aspects of human language are shared across species, the researchers say.

Professor Simon Kirby of the University of Edinburgh, an expert in the evolution of language, and Dr Claire Garrigue, a marine biologist who has studied humpback whales in New Caledonia for over 30 years, were also key contributors to the research.