Sure, call him Flipper, but he's probably already got a name among his own kind. Bottlenose dolphins appear to have individual identifying whistles, researchers in Scotland find. The scientists recorded the "signature whistles" of several of the animals in a group, along with other sounds they make. The team then played the sounds over underwater speakers. When a dolphin heard its own identifying sound, it would respond by singing it back, the BBC reports.
In other words, according to the scientists, they were answering to their own names. It makes sense that dolphins would have ways of referring to each other by sound: They "live in an environment where they need a very efficient system to stay in touch," says a researcher. "Most of the time they can't see each other, they can't use smell underwater ... and they also don't tend to hang out in one spot." Dolphins are the first animals to show such behavior, he adds. (Read more dolphins stories.)