Dolphins name themselves with a whistle

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, its “signature whistle,” Stephanie King and Vincent Janik of the University of St. Andrews in Scotland report July 22 in the Proceedings of the National Academy of Sciences. 

The signature whistle, a distinct tune each dolphin develops for itself and broadcasts to others, may act as a sort of audible nametag.

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

When dolphins heard their own signature whistles, they whistled the tune back, the pair found. Aside from humans, dolphins may be the only other mammals to name individuals.