Many animals use sounds to convey information. [Sound of wolf howl] Humans use particular vocal labels for objects and for people. We call these words, and names. A few creatures, such as parrots and dolphins, can learn specific vocal labels. And wild dolphins are known to have particular, individual signature whistles. Scientists at Scotland’s St. Andrews University wanted to know: can these whistles be used as labels? The researchers analyzed sounds from dolphins off Scotland’s east coast, and extracted these signature whistles. [Dolphin whistle sound] Then they altered the sounds so the calls wouldn’t sound exactly like the originating dolphin. [Altered dolphin whistle]
They played those sounds back to the dolphins, along with whistles from dolphins familiar to the animals and whistles from strangers. When the dolphins heard their own signature whistle [Altered dolphin whistle] they routinely responded with that same sound. [Dolphin whistle sound] That reaction only happened twice when they heard sounds from their pals and not at all when they heard the alien dolphin. The research is in the Proceedings of the National Academy of Sciences. [Stephanie L. King and Vincent M. Janik, Bottlenose dolphins can use learned vocal labels to address each other] The researchers think dolphin signature whistles serve as self-identification, and maybe even as a label for addressing each other—just like a name. —Cynthia Graber [The above text is a transcript of this podcast.] [Dolphin sounds courtesy of Stephanie L. King and Vincent M. Janik, Saint Andrews University] Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news.
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