for National Geographic News
Dolphins give themselves "names"distinctive whistles that they use to identify each other, new research shows.
Scientists say it's the first time wild animals have been shown to call out their own names.
What's more, the marine mammals can recognize individual names even when the sound is produced by an unfamiliar voice.
Bottlenose dolphins appear to develop so-called signature whistles as infants (just for kids: bottlenose dolphin fun facts).
The idea that they use these whistles to identify each other was first proposed in 1991 after individuals were heard to make their own unique sounds.
"The challenge was to show experimentally that the animals can use these independent voice features as signature whistles," said Vincent Janik of the Sea Mammal Research Unit at the University of St. Andrews in Scotland.
Janik is the lead author of a study on the dolphin whistles to be published tomorrow in the journal Proceedings of the National Academy of Sciences.
He says the idea that dolphins use names "was fairly hypothetical, and some researchers regarded it as not possible."
The research focused on wild bottlenose dolphins living in Sarasota Bay, Florida (map of Florida).
Acoustic recordings have been made of most of these dolphins, which have been studied for more than 30 years.
For the new study each dolphin's signature whistle was isolated from the recordings and then played back to the animals through underwater loudspeakers.
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