LONDON, July 23 (Xinhua) -- Dolphins have long been recognized as a smart animal. A new study by British researchers have even found that bottlenose dolphins address each other by using signature whistles.
Researchers at the University of St Andrews reported on Tuesday that, they conducted sound playback experiments with wild bottlenose dolphins on the east coast of Scotland.
Their earlier work published this year showed that dolphins often copy the signature whistles of their close relatives and friends.
This new study tests whether animals that are addressed with copies of their signature whistles really react to them. Researchers followed groups of wild dolphins and recorded the dolphin unique 'signature' whistles using a novel signature identification method.
They then played back either a computer version of an animal's signature whistle, or control whistles of either an unfamiliar animal or a familiar animal from the same population. Each dolphin only reacted when hearing the computer version of its own signature whistle, but not to the other whistles played back to it.
Researchers said this showed that dolphins can be addressed in this way was the missing link to demonstrate that signature whistles function as names.
"In experimental work, parrots are also good at learning novel sounds and using them to label objects. " Dr Stephanie King, who participated this study, said: "Our results present the first case of naming in mammals, providing a clear parallel between dolphin and human communication."
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