Researchers have found that part of the bottled dolphins living in the Shakbe area in western Australia have a particular skill: to eat with a sponge on their kisses in order to prevent them from being scratched by seafloor rubble.
The Associated Press quoted an article published in the British magazine Open Science of the Royal Society, which found that some of the bottled dolphins hunted with a sponge, big as a melon, small as a softball. These sponges can protect dolphins from injuries when they “paw” under the water for food.
Researchers say that this skill belongs to the “ancestral” skills of bottlenose dolphins, often taught by mothers to future generations. They observed, however, that only 5 per cent, or about 30 dolphins, were skilled in the Shakbe area, as the sponges were not as easy to operate as they seemed. The marine biologist Ellen Rosse Jacobs of the University of Aarhus, Denmark, who participated in the study, said that dolphins were navigating by echo, and that kisses affected the echo and interfered with its precise positioning of objects.
According to oceanographers, hunting with sponges is like “hunting with eyes blinded, hunters need to be very good and trained to do so”.
Dolphins usually live with their mothers for three or four years after birth and learn survival skills. The marine ecologist Boris Volm of the University of Dalhousie, Canada, who was not involved in the study, said: “It will take years to acquire this particular skill, and not every dolphin will last.