Bottlenose Dolphins Can "Name" Themselves And Call Out Names Of Others, Study Finds

A recent study on the whistles of bottlenose dolphins has found that the mammals might communicate in ways very similar to humans.

Previous research had concluded that bottlenose dolphins "name" themselves with a signature whistle that identifies them and contains other information. The results from a new study published in February suggest that dolphins also know the whistle "names" of other dolphins and use the whistles to call out to other dolphins they know. The findings suggest the mammals are capable of communicating in ways previously thought only to be done by humans.

While this has yet to be definitively proven, the results resemble a linguistic feat known as "referential communication with learned signals," which has always been thought to be a hallmark of humanity.

"This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defense of resources," the study's authors write, according to Mother Nature Network. This helps differentiate dolphins' vocal learning from that of birds, they add, which tend to address one another in a more 'aggressive context.'"

The study's authors believe the dolphins use the whistles affiliatively and copy another dolphin's whistle when they want to reunite with that specific individual.

"It is possible that signature whistle copying represents a rare case of referential communication with learned signals in a communication system other than human language," they write. "Future studies should look closely at the exact context, flexibility and role of copying in a wider selection of species to assess its significance as a potential stepping stone toward referential communication."

But the dolphins don't copy the whistles precisely, instead adding subtle variation that may also identify them as the one "speaking."

Heidi Harley, a professor of psychology at New College of Florida, is a leading expert on cognitive processes in dolphins, she told Discovery News that she agrees with the paper's conclusions.

"This study provides evidence that copies of signature whistles include elements that differ from the whistles of the original whistler, while still maintaining the changes in frequency over time that allow a listener to identify the original whistler."

The study was published  in the Proceedings of the Royal Society B.