These creatures use much more complex communication than we once thought.
“They’re all kind of using the same language, but phrasing things slightly differently,” said Mauricio Cantor, assistant professor in OSU’s Marine Mammal Institute and a co-author on the study. Cantor is referring to something called “identity codas” — unique sequences of Morse code-like clicks that serve as symbolic social markers. It’s a bit like an audio version of a football jersey: you tell someone you don’t know that you belong tos a particular tribe. “As symbolic markers, the identity codas would serve as a flag: an arbitrary but useful way to advertise membership of a particular group.”
The researchers led by Taylor Hersh of the Max Planck Institute for Psycholinguistics in the Netherlands, analyzed over 23,400 sperm whale codas recorded in 23 specific regions in the Pacific spanning from the Galapagos to Tonga, Japan, and Chile. The recordings came were gathered over a course of almost 40 years.
The codas are a tell-tale sign of culture, passed down from generation to generation through social learning. When they’re young, calves don’t know any specific codas but they learn them by mimicking the adults and then keep the codas consistent. It’s a whole new way of communicating belonging, one that’s completely different to how we humans communicate.
“The bigger picture here is this gigantic gap that we perceive (or insist on perceiving) between humans and everything else on Earth,” Cantor said. “One of the main things that used to separate us is the ability for humans to have culture. This notion is slowly being eroded over time with studies showing that animals do learn, and they pass that information on, which can become little traditions that are stable over time.”
Such cultural signs are very rare in the animal world, but it’s not surprising that sperm whales use them, given how smart and social these creatures are. Sperm whales have a surprisingly rich and deep culture, learning useful things from each other and communicating in a strikingly complex way.
“Culture, a pillar of the remarkable ecological success of humans, is increasingly recognized as a powerful force structuring nonhuman animal populations,” the researchers write in the study.
Whales use these codas differently in different situations. When they know they’re the only clan in a particular geographical area, they use the codas sparingly. But in a crowded area with multiple clans, where the whales don’t exactly know if the nearby whales are part of their clan, they use it more often to distinguish themselves.
Not only does this show us a new side of whale culture, but it also helps researchers delimitate the different whale clans and their geographic range. Using the data, the team identified one previously unknown clan and two lesser-known clans for the first time. Initially, the team thought they were dealing with four clans, but the coda data showed at least seven claims, and possibly more in less-studied regions. The team identified a “Regular” clan, that uses clicks are regular intervals, a “Plue One” clan, that has a slight pause before the last click, a “Short” clan, a “Rapid Increasing” clan, a “Four-Plus” and a “Slow increasing” clan, as well as a “Palindrome” clan — all with suggestive names. However, researchers emphasize that some areas were understudied and some clans may have evaded detection.
Ultimately, this goes to show just how complex and cultural non-human societies can be. As our society continues to develop and change, we’re also changing the world around us. It is perhaps important to keep in mind that we’re not the only intelligent species on this planet.
The study has been published in PNAS