Darling, it’s better down where it’s wetter; take it from me. Photo: Reinhard Dirscherl/Corbis

Whales might not have opposable thumbs or manipulative digits, but they do rival human beings when it comes to brainpower. Multiple studies on various species of whale have determined that they’re incredibly intelligent — perhaps even smarter than we are — and one hallmark of their genius is the way they communicate. Whales talk to each other using patterns of clicks called codas, and a new study suggests those codas vary significantly depending on which ocean a whale is from. In other words, patterns of communication between whales vary depending on what region they inhabit: Just like people, whales have accents.

The study, published in Royal Society Open Science, specifically looked at communication between groups of sperm whales living in the Caribbean off the island of Dominica. Since male sperm whales are fairly solitary and therefore don’t constitute the best source material for a study about communication, Dr. Shane Gero, the study’s lead author and a researcher at Aarhus University in Denmark, only examined calls among pods of female whales and their young offspring. (Gero had already spent eight years studying this particular group of whales, so he was about as familiar with their social groupings as possible — he recorded their calls for six of those years, amassing one of the largest samples of whale calls to date.)

Gero and his team analyzed those calls by categorizing them according to the number of clicks and the time interval between each click. They identified a total of 21 call types, but two of those types made up 65 percent of all calls recorded. Apparently every whale, no matter its social group, performed these two types of calls so identically that researchers couldn’t tell them apart, even using computers. What’s more, these two types of calls have “dominated repertoires in this population for at least 30 years.” They concluded that the persistence of these two types of calls — which aren’t evident in, say, Pacific whale populations — mean they’ve been culturally transmitted over generations. Their data also showed that juveniles and calves produced a wider variety of coda types, which supports the theory that a standardized coda is something they learn over time.

Gero contrasts the sperm whales’ regional coda with other calls they make: variable individual calls and shared family calls. The fact that there are so many layers of complexity in sperm-whale communication jibes with something called the social complexity hypothesis, which predicts that species with more complex social structures will also have more complex methods of communication.

Whether or not whale communication is as complex and varied as human communication is impossible to say. No matter how much time people like Gero spend studying whales (and he spends a lot of time studying whales), the truth is that unless we learn to speak whale, their rich inner lives will remain a mystery to those of us stuck on dry land.