A new study has discovered that that bottlenose dolphins call out to each other by names, just like human beings, suggesting that the concept of naming individuals is not exclusive to our species.
According to the study by researchers from University of St. Andrews in Scotland, dolphins call out to each other by using "signature whistles."
While it was already known to science closely related dolphins do copy each other's whistles, it wasn't clear if there were any sort of signature whistles.
For the study, the researchers followed different groups of wild dolphins off the east coast of Scotland and closely monitored each of their signature whistles for a span of four months. They checked if there were any repetitive styles of whistle.
With the help of an onboard computer, the scientists then created synthetic versions of the dolphin's signature whistles without their vocal characteristics to check if the dolphins responded to the whistle pattern itself without recognizing their own voices.
The researchers also recorded and created synthetic versions of non-signature whistles.
When the synthetic versions of signature whistles were played from an underwater speaker, it was found that dolphins responded. While some of them responded by whistling back immediately, others approached the boat soon after responding. This suggested that the signature whistles may be helping lost animals reunite with their group, lead author of the study, marine biologist Stephanie King said according to a report in Los Angeles Times.
Laela Sayigh, a marine biologist at Woods Hole Oceanographic Institute in Massachussetts said that all signature whistles are different from each other. She added that females especially have very distinctive whistles which may aid calves recognize their mothers more easily.
However, Sayigh said it is not clear as to how dolphins come up with their signature whistles.
Though there is a theory that there is learning involved in the process, it is not confirmed.
"We don't really have an exact answer," Sayigh said.
Sayigh further said that the study may help answer larger questions.
"There's a big question looming as to whether dolphins use whistles in the way we use words," Sayigh said.
"We can say 'chair' and visualize 'chair' without having to see one at the same time," Sayigh said. The question if dolphins can do the same with whistles.
King said that the research team now plans to study other whistle types.
"I think we can really open the door now and look at this in more animals," she added.
The study was published on Monday in the Proceedings of the National Academy of Sciences.