Dolphins Use Unique Whistle to Call Each Other (VIDEOS)

Researchers from the University of St Andrews in Scotland discovered that marine mammals use a unique whistle to identify one another. The proof of this is that the animals responded when they heard their unique call - which is similar to the function of a human name - played back to them.

The researchers first recorded a group of wild bottlenose dolphins and captured each animal's unique sound. Using underwater speakers, the group played back the signature sound.

"We played signature whistles of animals in the group, we also played other whistles in their repertoire and then signature whistles of different populations - animals they had never seen in their lives," BBC quoted Dr Vincent Janik from the university's Sea Mammal Research Unit.

Based on their observation, the dolphins responded only to their unique calls which were done by sounding their whistle back.

Mr Janik theorised that the skill was developed to help the mammals stick together in a group in their very vast underwater world.

"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 sport, so they don't have nests or burrows they return to," he explained.

Prior research had found that the calls were used often, and dolphins in the same groups could learn and copy the unusual sound. But in the new study, published in the Proceedings of the National Academy of Sciences, it is the first time they respond to the unique whistle that serves as their name.

Mr Janik said understanding how the skilled evolved in different groups of animals could help humans understand better how communication developed in homo sapiens.

Stephanie King, a colleague of Mr Janik, said, "Animals have been found to use calls to label predators or food but these calls are inherited and not influenced by learning ... The use of new or learned sounds to label things is rare in the animal kingdom. However, it is ubiquitous in human society and at the heart of human language."