Dolphins are able to carry on multiple conversations simultaniously.
Dolphins apparently have a system of identifying themselves to each other similar to the way you and I use names.
Scientists have actually known since the 1960s that this system existed. Basically, each dolphin creates their own “signature” whistle when they’re very young. In studies of captive dolphins, they used this whistle mainly when they got separated from the rest of the group. It was like a way of saying, “Hey, I’m over here!” Or, given the environment, perhaps some version of “Marco! Polo!”
But at Not Exactly Rocket Science, Ed Yong writes about a new study of wild dolphins that has really increased our understanding of signature whistles and how dolphins use them…
Quick and Janik recorded the calls of swimming dolphin pods using underwater microphones. From 11 such recordings, they worked out that dolphin groups use their signature whistles in greeting rituals, when two groups meet and join. Only 10 per cent of such unions happen without any signature whistles. And the dolphins use their signatures nine times more often during these interactions than during normal social contact. The signature whistles clearly aren’t contact calls, because dolphins hardly ever use them within their own groups. Mothers and calves, for example, didn’t exchange signature whistles when travelling together. And they’re not confrontational claims over territory, because bottlenose dolphins don’t have territories.
Instead, Janik thinks that dolphins use the whistles to identify themselves, and to negotiate a new encounter. The human equivalent would be saying, “My name is Ed. I come in peace.”
Quick and Janik also found that the dolphins don’t mimic each other’s signatures when they meet up. Justin Gregg from the Dolphin Communication Project says, “In other words, dolphins are not shouting out “Hey there Jerry” to each other, they are saying “it’s me, Tim!” He adds, “We really have no idea when or why they use these whistles. This study has uncovered a brand new function for the signature whistle, which makes it rather exciting. They appear to be identifying themselves to social partners after a prolonged separation.”