Seven ancient “clans” of sperm whales live in the vast Pacific Ocean, announcing their cultural identity through distinctive patterns of what happens within their song, according to a new study.
This is the first time cultural markers have been observed among whales, and they mimic markers of cultural identity among human groups, such as distinctive dialects or tattoos.
The discovery is also a step towards a scientific understanding of what whales say to each other in their underwater songs – something that remains a mystery despite years of research.
Bioacoustician Taylor Hersh, a postdoctoral researcher at the Max Planck Institute for Psycholinguistics in Nijmegen in the Netherlands and lead author of the study published this month in the Proceedings of the National Academy of Sciences, said that sperm whales frequently exchange streams of loud clicks with each other. others when they rest near the surface between dives into deeper waters – sometimes more than a mile down – for prey such as squid and fish.
The click streams are divided into what are called “codas” and the calls are known as sperm whale “songs” — although they are not very musical and can sound a bit like hammering and squeaking (sonar operators used the Fleets to call sperm whales. “carpenter fish” for this reason).
No one knows what sperm whale codas mean, but they can have specific rhythms and speeds, called “dialects,” Hersh said. And the new study shows that they include specific patterns – bursts of what happens every few seconds, like fragments of Morse code – that the whales use as “identification codes” to announce their membership of a particular clan.
“Identities are really unique to the different cultural groups of whales,” she said.
The study also shows that sperm whales emphasize their vocalizations when rival clans are nearby — a tell-tale behavior also seen in humans — and as a result whales from different clans don’t usually interact with each other when they are in the same waters, she. said.
The study analyzed more than 40 years of recordings of underwater sperm whale calls made at 23 locations across the Pacific Ocean, from Canada to New Zealand to Japan to South America. From these, the researchers extracted more than 23,000 click patterns, and then used an artificial intelligence system to determine which identity codes they contained.
They have now determined that there are at least seven “vocal clans” of sperm whales across the Pacific, each with its own identification code, Hersh said.
Each clan can contain thousands of individual sperm whales, and calls from members of the same clan have been recorded at the ends of the Pacific Ocean, sometimes more than 9,000 miles apart. It is not known how many sperm whales there are in the world’s oceans, but it is estimated that there may be as few as 360,000; about half of them could live in the Pacific Ocean.
And the sperm whale clans could be thousands of years old. Hersh said that mother and daughter sperm whales always share the same vocal clan. However, males often travel in groups and may be more flexible in their flock membership.
Since sperm whales live for about 70 to 90 years, the age of a grandmother and her granddaughter could be about 150 years. “So it seems that clans are hundreds of years old, and maybe much longer,” she said.
Sperm whales spend most of their lives far from humans and in a very different environment – diving in the deep ocean – little is known about their behaviour. Although researchers can’t yet tell how the identity codes in sperm whale songs reflect other distinctive aspects of their clan culture, there is evidence that different clans use different techniques to hunt for prey, Hersh said.
Gašper Beguš, an assistant professor of linguistics at the University of California Berkeley who was not involved in the study, compares the vocal clans of sperm whales to groups of dialects among humans.
A well-known linguistic study several years ago found that islanders on Martha’s Vineyard were more likely to emphasize their distinct island dialect when speaking to non-islanders, he said.
Similarly, the researchers in the latest study found that sperm whales were more likely to emphasize their clan dialects in regions where they were more likely to meet members of other clans, he said.
Beguš is part of the CETI Project — the Cetacean Transfer Initiative — established last year to understand the sounds of sperm whales. The project will combine linguistic studies and machine learning to discover what sperm whales are saying to each other, and possibly enable them to communicate interspecies.
“We are starting to collect data with microphones on whales and in the water,” he said. “We’re following their behavior, and we’re learning a lot about their environment and their social structure.”
While it was previously known that sperm whales exchange information in codes, this is the first time the identification codes of whale clans have been determined – a finding that will be key to deciphering all of their songs, he said. .
Dolphin and whale scientist Janet Mann, a professor of biology and psychology at Georgetown University who was also not involved in the latest study, agreed that the research could help to better understand the speech of sperm whales .
“As the authors note, we still understand very little about the function of sperm whale codas,” she said in an email. “This is an important step in determining not only the function and meaning of codas, but the forces that shape cultural evolution in animals.”
This article was originally published on NBCNews.com