A dolphin living alone in the Firth of Clyde has learned to communicate with local harbour porpoises, a marine expert has claimed.

The short-beaked common dolphin, nicknamed Kylie by locals, has made his home around a navigational buoy between Fairlie and the Isle of Cumbrae, after he is thought to have got lost from his group.

The area is not commonly visited by dolphins and Kylie has mostly been exposed to sounds produced by other species, particularly the harbour porpoise.

Now audio testing suggests the dolphin has altered the frequency of the clicking he makes so as to be understood by the porpoises.

If validated by further research, the findings would mark the first time a common dolphin has shown it can imitate other species in order to communicate.

University of Strathclyde PhD research student Mel Cosentino studied underwater audio recordings and found that Kylie has learned to increase the frequency of the clicking sounds made to navigate and hunt to match that of the porpoises.