Researchers at the University of St Andrews have found that dolphins call each other by a signature whistle that functions much like a human name, a rare linguistic feat among nonhuman animals.
Humans are not the only animals to give each other names, suggests new research on dolphin communication.
Researchers have found that wild bottlenose dolphins call back to a recorded copy of their own signature whistle, in effect answering to their own names. This finding joins accumulating and compelling evidence that humans might not have a monopoly on learned vocal labeling, the ability to pair acoustic signals with specific objects.
“Our results present the first case of naming in mammals, providing a clear parallel between dolphin and human communication,” said Stephanie King, a marine biologist at University of St Andrews and co-author on the study, published in Proceedings of the National Academy of Sciences. “It’s now clear that signature whistles have meaning in that they are labels for particular individuals and can be used by animals to address a social companion.
Last year, King and colleagues at St Andrews had found that captive dolphins whistled to close relatives when separated. To signal to their friends, the dolphins copied their relatives’ signature whistles, much as human friends might call each other’s names from across a pool.
But researchers had been unsure if that language was unique to dolphins in captivity – did dolphins have names in the wild?
To find out, researchers first recorded the signatures whistles of pods of wild dolphins off the coast of Scotland, in St. Andrews Bay. The scientists then modified the “voice” of the whistles, to ensure that the dolphins would be reacting to the whistle itself, and not just employing voice recognition. Using underwater speakers, they then played the recordings to the dolphins – and waited, and listened.