It is counterintuitive that a dolphin can sound like a porpoise, but actually isn’t communicating with it. It is known that dolphins and porpoises and very similar looking marine animals. One similarity is that they both make clicking noises to communicate, but dolphins use a frequency of about 100 KHz and porpoises at about 130 KHz. Researcher and PhD student Mel Cosentino of the University of Strathclyde in Scotland studied the clicking of a dolphin named Kylie that lived with at group of porpoises in western Scotland. Cosentino records and analyzed the clickings of Kylie when he is alone and when he is with the porpoises for a couple of months. After months of Kylie the dolphin living with porpoises, research from the University of Strathclyde found that Kylie’s clicking became higher than normal, and closer to that of his porpoise companions.
Although Kylie’s may mean that she is communicating with porpoises, it is unclear whether she is actually speaking to them or just imitating them, like when we bark back at dogs. Cosentino should know soon whether Kylie really is communicating or merely imitating. If further analysis showed the Kylie is imitating the porpoises, it would be the first time a common dolphin has demonstrated an ability for production learning, which is when it has learned to imitate another species.