A Dolphin by Any Other Name
You probably know that dolphins use sounds like whistles and clicks to hunt and communicate, but you might not know that every dolphin has what’s called a “signature whistle”. From four to six months old, young dolphins develop a unique whistle, and they use this distinctive vocal pattern consistently throughout their lives.
For a while, researchers were unsure about its purpose, but work by biologists Stephanie King and Vincent Janik of Scotland’s University of St. Andrews confirmed that these whistles are used as identity markers. Following groups of bottlenose dolphins off the east coast of Scotland, they used hydrophones to detect their sounds and to record signature whistles. As control, King and Janik broadcasted unfamiliar whistles to the dolphins, which they ignored—but when their own signature whistles were played, modified slightly so it sounded like a different dolphin was calling, they whistled back and even began to swim towards the sound.
This suggests that they use them to address or identify each other—as King said, these results “present the first case of naming in mammals, providing a clear parallel between dolphin and human communication.” Sometimes upon hearing their own whistles, the dolphins just repeated it as if to say ‘I’m here!’, and other times they responded with a string of other whistles.
According to King, “The next step is to look into the function of non-signature whistles to gain an even greater insight into their complex communication system.”