Scientists say dolphins call out to each other 'by name'

LOS ANGELES, CA (Catholic Online): Researchers at the University of St. Andrews in Scotland says they have discovered that when the dolphins hear their own call played back to them, they respond.

According to a study published in the Proceedings of the National Academy of Sciences, Dr. Vincent Janik, from the university's Sea Mammal Research Unit, says "(Dolphins) live in this three-dimensional environment, offshore without any kind of landmarks and they need to stay together as a group."

It's long been theorized that dolphins use distinctive whistles in much the same way that humans use names. Previous studies found that these calls were used frequently. Dolphins in the same groups were able to learn and copy the unusual sounds.

The recent study was 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 and then played these calls back using underwater speakers.

"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," Janik explains.

Individual dolphins only responded to their own calls, by sounding their whistle back.

The team believes the dolphins are displaying human-like behavior, i.e., when they hear their name, they answer.

Janik says that this skill probably came about in order 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.

The researchers believe this is the first time this has been seen in an animal, although other studies have suggested some species of parrot may use sounds to label others in their group.

Janik notes that understanding how this skill evolved in parallel in very different groups of animals could tell us more about how communication developed in humans.