We have given names to many bottlenose dolphins, from Flipper to Darwin. But in the wild, these animals have their own badges of identity—signature whistles that they develop during their early years and that are unique to them.

These whistles seem a lot like human names. The comparison isn’t perfect, but it’s now stronger than ever after Stephanie King and Vincent Janik managed to address individual wild dolphins with recordings of their own signatures. The dolphins responded by calling back, but only when they heard their own whistle. “I think our results do present the first case of naming in mammals, providing a clear parallel between dolphin and human communication,” says King.

The evidence that dolphins use signature