Morigenos researchers have discovered that individual dolphins can be identified by their faces, “inventing” a novel method of dolphin identification. They presented their findings in a study, published today in Marine Mammal Science, the central scientific journal for studies of marine mammals: http://onlinelibrary.wiley.com/doi/10.1111/mms.12451/full
It has long been known that individual dolphins can be identified by natural markings on dorsal fins. Thanks to these markings, we know that about 150 dolphins live in the Gulf of Trieste, studied by Morigenos researchers since 2002. But markings on fins can change, and calves are usually not sufficiently marked to allow identification at all. Therefore, additional means of telling dolphins apart can be very useful. A few years ago, Morigenos researchers discovered that dolphins can also be identified by their faces, which was not known previously. This was first discovered by Tilen Genov, Morigenos president and the first author of the study, while studying dolphins in Slovenian waters and the Gulf of Trieste. Together with an international team of scientists, he designed a study in which participants both experienced and inexperienced in dolphin fin identification were asked to match photographs of dolphin faces. Results showed that both groups of participants can tell individual dolphins apart based on their faces, even when comparing the left side of the face to the right one. The study also showed that facial features in dolphins are consistent over time and can be used over the long term.
This new method cannot replace the identification based on dorsal fins, but it can complement it. Unlike dorsal fins, faces are not subject to the same level of change due to external influences, and may therefore be more reliable over long periods. This new method is also very applicable to calves, which usually do not carry sufficient dorsal fin markings to be recognisable after they leave their mothers, and can therefore help increase cross-generational knowledge. It may be particularly suited to species that do not carry many markings on dorsal fins, or those that lack dorsal fins altogether.