Dolphin mothers pass tool use to daughters

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Andreas von Bubnoff


Bottlenose dolphins are known to be smart, but a study of tool use has emphasized just how clever these mammals can be. Female dolphins in an Australian bay seem to be learning from their mothers how to stick marine sponges on their noses to help them hunt for fish, researchers say.

"It is the first documented case of tool use in a marine mammal," says Michael Krützen of the University of Zurich, Switzerland, who led the study into how the trick is passed from one generation to the next. Rather than being an inherited trait, the tool use is probably being learned by daughter dolphins from their mothers, the researchers report in the Proceedings of the National Academy of Sciences1.

Sponge-using dolphins (Tursiops truncatus) were first described in 1997 in Shark Bay, 850 kilometres north of Perth, Australia2. Since then, all dolphins known to use this tool have come from the same bay, and the vast majority have been female. Direct observations have been rare, but researchers think the dolphins use the marine sponges to disturb the sandy sea bottom in their search for prey, while protecting their beaks from abrasion.

http://www.nature.com/news/2005/050606/full/050606-2.html