Scientists have been fascinated for years by the complex repertoire of high-pitched calls of these highly social and intelligent animals. But Mr Janik has proved that these mammals actively engage in conversation, according to an article in Science magazine. He recorded wild bottlenose dolphins during seven summer days in Scotland's Moray Firth in the mid-1990s. His team picked up 1,719 whistles from groups of up to 14 dolphins, with 179 involving interactions between individuals. The dolphins tended to be about 179 metres apart when they greeted each other, though at least one pair were 579 metres apart.
Dolphins develop their own unique signature whistle in the first few months of their life.
But they can also imitate new sounds accurately at the first attempt - and retain this ability throughout their lives. This means that many dolphins may include other individuals' calls in their range of whistles because they learn to imitate each other's call signs. The character of such addressing might be either aggressive or affiliative. However, matching could also signal alliance membership to third parties, or be used to prevent deception of third parties by a whistle-copying dolphin. He says this is important because the ability to match recognitions signals is thought to be a vital step in the evolution of human languages.