In behavior previously only attributed to humans, bottlenose dolphins have been found to use distinct sounds to call out for companions, the equivalent of using names to identify each other.
The dolphins use specific whistles to identify one another, according to a study in the
Proceedings of the Royal Society.
Researchers have known that bottlenose dolphins use unique sounds to identify themselves, and they have found the noises and whistles are encoded with information that let other dolphins know who they are, as if to say, “Hey everybody! I’m an adult healthy male named George, and I mean you no harm!” according to
Discovery News.
The new study said dolphins are able to reproduce the "signature noises" of their companions, particularly when separated from one another.
“Animals produced copies when they were separated from a close associate and this supports our belief that dolphins copy another animal’s signature whistle when they want to reunite with that specific individual,” said Stephanie King of the University of St. Andrews Sea Mammal Research Unit, the main author of the PRSB study.
King and her team collected data from wild dolphins between 1984 and 2009. They also studied four captive dolphins, and determined they could refer to objects using signals.
The study found that dolphins imitated their peers within a few degrees of frequency, adding their own "tone of voice."
“A dolphin emits its signature whistle to broadcast its identity and announce its presence, allowing animals to identify one another over large distances and for animals to recognize one another and to join up with each other,” King said. “Dolphin whistles can be detected up to 20 km away (12.4 miles) depending on water depth and whistle frequency.”
Dolphins have been known to show other unique behaviors. Mother dolphins can teach their young to use tools. A 2005 report showed dolphins in western Australia used marine sponges as protection on their snouts while foraging for food.
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