Just two dolphins, probably talking smack about you. Photo: Flickr/Jason Pratt
When a bottlenose dolphin sees a shark is about to attack its friend, he or she probably says something like "Hey, Flipper, watch out for that shark." That's both because Flipper is probably an extremely common dolphin name and because scientists think dolphins are so smart that they give each other names.
According to the study, done by researchers at Scotland's University of St. Andrews and published in Proceedings of the National Academy of Sciences Monday, dolphins use "learned signals" to communicate with each other.
"Bottlenose dolphins develop their own unique identity signal, the signature whistle," the report states. "This whistle encodes individual identity independently of voice features."
But that's not all. When dolphins hear their whistle, or name, they respond by calling back, and the animals "did not respond to whistles that were not their own signature," so they know to politely ignore when their podmate talks to someone else.
Lots of animals communicate, of course, but most scientists believe that it's an innate feature built in as a defense mechanism, with the structure of those sounds "predetermined from birth." Other animals, such as elephants, songbirds, and bats, are believed to have more advanced signaling abilities, but "only parrots and dolphins [and humans] have been found capable of using arbitrary, learned signals to label objects in experimental studies."
We've long known that dolphins and whales are some of Earth's most intelligent creatures, using a series of whistles and clicks to communicate. There is even some evidence to suggest that dolphins in captivity are able to understand human sign language. Fringe researcher John C. Lilly tried to speak to them through a computerized human-to-dolphin translator and copious amounts of LSD. And, as a side note, who could ever forget this Simpsons Treehouse of Horror episode?
To test their hypothesis that wild dolphins would only respond to their own signature whistles, researchers recorded the whistles of wild dolphins off the coast of Scotland. They then played back those whistles, along with whistles of dolphins from other populations. The dolphins only responded to their own whistle being played back, and ignored those of unfamiliar dolphins.
"This result supports the hypothesis that signature whistle copies can be used to label or address speciﬁc individuals," they write.
The researchers note that, unlike songbirds, which are more likely to respond to the song of unfamiliar birds as a sort of evolutionary gene-mixing act or as a territorial defense, dolphins "use single whistles as social sounds in affiliative contexts."
There is still much scientists don't know about dolphin language, and we're still not good at interpreting what they're saying, but given their proclivites for casual sex and now this, we know there might be an underwater market for dolphin baby name books.