London:
Hey Dolly, let's go swimming!
Dolphins have 'names' by which they call for each other just like humans do, a new study has found.
The marine mammals use a unique whistle to identify each other and respond when they hear their own call played back to them, researchers found.
"(Dolphins) live in this three-dimensional environment, offshore without any kind of landmarks and they need to stay together as a group," Dr Vincent Janik, from the University of St Andrews in Scotland, said.
"These animals live in an environment where they need a very efficient system to stay in touch," said Janik.
Scientists suspected for long that dolphins use distinctive whistles in much the same way that humans use names.
However, this is the first time that the animals response to being addressed by their "name" has been studied.
Researchers recorded a group of wild bottlenose dolphins, capturing each animal's signature sound. They then played these calls back using underwater speakers, BBC News reported.
They found that individuals only responded to their own calls, by sounding their whistle back.
The dolphins are acting like humans: when they hear their name, they answer, researchers said.
Janik said this skill probably came about to help the animals to stick together in a group in their vast underwater habitat.
"Most of the time they can't see each other, they can't use smell underwater, which is a very important sense in mammals for recognition, and they also don't tend to hang out in one spot, so they don't have nests or burrows that they return to," Janik said.
Understanding how this skill evolved in parallel very different groups of animals could tell the scientists more about how communication developed in humans, he said.