|New Evidence Reveals Use of Dolphins' 'Signature Whistles'|
|By JON M. CHANG||Jul 23, 2013, 3:31 PM|
They escape from aquarium tanks. They locate underwater mines. Now, a new paper published in the journal Proceedings of the National Academy of Science claims that dolphins recognized their own name when called.
Vincent Janik, one of the authors of the study and a biology researcher at the University of St. Andrews in Scotland, said that the name is actually a specific type of dolphin vocalization that the animals respond to.
"They're these high pitched whistles that have a little bit of a melody," he told ABC News. These sounds are referred to as "signature whistles."
Janik and his colleague, Stephanie King, cruised along the east coast of Scotland looking for bottlenose dolphins. Though it's a far cry from swimming with animals in warm tropical waters, Janik says that wild dolphins aren't impossible to find in the United Kingdom. "There's maybe about 150-180 of them out here," he said.
After spotting and identifying a dolphin in the wild, the researchers would play one of three different sounds: a modified sound clip of that dolphin's signature whistle, a signature whistle of one of its podmates, or the signature whistle of a completely foreign dolphin.
They played the dolphin's own signature whistle and the animal would come up and approach the boat and whistle back. However, the dolphin didn't respond to the other two types of whistles and mostly kept about its business.
It may seem odd that the dolphins don't react much to the whistles of their fellow herdmates, but Janik says that copying a dolphin's signature whistle just right is part of their social group.
"This copying only occurs between closely associated animals, like between mothers and their calves," he said. Dolphins only need to respond to their own signature whistles, since any socially relevant animal will have learned how to copy it. "It says to them, 'I know that this [whistle] is a friend.'"