Seven ancient “clans” of sperm whales live in the vast Pacific Ocean and proclaim their cultural identity through distinctive clicking patterns in their songs, according to a new study.
It is the first time cultural markers have been observed in 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.
Bioacoustics Taylor Hersh, a postdoctoral researcher at the Max Planck Institute for Psycholinguistics in Nijmegen and lead author of the study published this month in the Proceedings of the National Academy of Sciences, said sperm whales often exchange loud clicks with each other. others when resting on the surface between dives into deeper waters—sometimes more than a mile down—for prey like squid and fish.
The streams of clicks are divided into so-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 (Naval sonar operators used to call sperm whales “carpenter fish” for this reason).
No one knows what all the sperm whale codas mean, but they can have distinctive rhythms and tempos, known as “dialects,” Hersh said. And the new study shows they contain specific patterns — bursts of clicks lasting just a few seconds, like fragments of Morse code — that the whales use as “identity codas” to announce their membership in a particular clan.
“Identity codes are really unique to the different cultural groups of whales,” she said.
The study also shows that sperm whales emphasize their dialect when rival clans are nearby — a telltale behavior seen in humans as well — with the result that whales from different clans usually don’t interact with each other when occupying the same waters, she said. .
The study analyzed more than 40 years of recordings of underwater calls from sperm whales at 23 locations in the Pacific Ocean, from Canada to New Zealand and Japan to South America. From this, the researchers extracted more than 23,000 click patterns and then used an artificial intelligence system to determine which of them were distinctive identity codes.
They’ve now determined that there are at least seven different “vocal clans” of sperm whales across the Pacific, each with their own identity codes, Hersh said.
Each clan could consist of thousands of individual sperm whales, and calls from members of the same clan are 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 are only 360,000; about half of them could live in the Pacific Ocean.
And the sperm whale clans can be thousands of years old. Hersh said mother and daughter sperm whales always share the same vocal clan. However, males often travel between groups and can be more fluid in their clan membership.
Since sperm whales live about 70 to 90 years, the age of a grandmother and her granddaughter can be about 150 years. “So clans certainly seem to be 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 into the deep ocean — so little is known about their behavior. While researchers can’t yet say how the identity codas in sperm whale songs reflect other distinctive aspects of their clan culture, there’s evidence that different clans use different techniques to hunt 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 dialect groups among humans.
A well-known linguistic study from several decades ago found that islanders on Martha’s Vineyard were more likely to emphasize their signature island dialect when speaking to people who were not from the island, he said.
Similarly, in the latest study, the researchers found that sperm whales were more likely to emphasize their clan dialects of clicks in regions where they were more likely to encounter members of other clans, he said.
Beguš is part of Project CETI — the Cetacean Translation Initiative — created last year to decipher the sounds of sperm whales. The project combines linguistic studies and machine learning to find out what sperm whales say to each other, and perhaps to enable interspecies communication with them.
“We’re starting to collect data with microphones on whales and in the water,” he said. “We monitor their behavior and we learn a lot about their environment and their social structure.”
While sperm whales have been known to exchange information in codas, this marks the first time whale clan identity codes have been established — a finding that will be crucial to deciphering their full 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 research, agreed the study could help better understand sperm whale speech.
“As the authors note, we still understand 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 also the forces that shape cultural evolution in animals.”
This article was originally published on NBCNews.com