A dolphin nicknamed Kylie which has lived mainly alone in the Firth of Clyde for over 15 years, seems to like the company of harbour porpoises and research now suggests the dolphin appears to have learnt to produce sounds similar to those of the porpoises. Common dolphins have peak frequencies below 100 kilohertz (KHz) while for harbour porpoises it is around 130KHz.
University of Strathclyde PhD research student Mel Cosentino analysed endless audio recordings of Kylie’s vocalizations, (made by volunteers from the Clyde Porpoise group) both when the dolphin is alone and when he interacts with porpoises. The results, as yet unpublished, show Kylie regularly produces clicks with peak frequencies over 100KHz, in fact reaching over 130KHz, when accompanied by harbour porpoises, much more often than when he is alone – suggesting that he has learned to imitate his companions’ “language” in order to interact with them on a regular basis.
If validated by further research, it would be the first time a common dolphin, either in captivity or the wild, has demonstrated an ability for production learning, where it has learned to imitate another species. While some whales, dolphins and purposes have been observed to change their frequencies before, scientists have not been able to confirm that this was in order to communicate with each other.
