Dolphins name themselves

To call a dolphin, just whistle a squeaky shout-out.

Bottlenose dolphins answer to high-pitched bursts of sound. But each animal responds to only one specific trill. That trill is called its “signature whistle,” explain Stephanie King and Vincent Janik of the University of St. Andrews in Scotland. Their new finding appeared June 22 in the Proceedings of the National Academy of Sciences.

Each dolphin develops a signature whistle — a distinct tune — for itself. Dolphins broadcast their tunes to others. The tunes seem to act as a sort of audible nametag.

Scientists knew dolphins exchanged signature whistles when meeting at sea. No one knew, however, if the animals responded to these “names.” King and Janik recorded wild dolphins’ chirps and squeaks and then played the signature whistles back to the animals.

When a dolphin heard its own signature tune, it whistled the tune back, the scientists found. Aside from humans, dolphins may be the only other mammals to name individuals.