A study published Wednesday in the Proceedings of the Royal Society B explains that bottlenose dolphins have been observed calling one another by name, in a groundbreaking discovery that extends a behavior previously only seen in humans to a member of the animal kingdom.
Researchers have known for some time that dolphins have unique, individual whistles that identify themselves to fellow dolphins nearby, but what caught the ear of researcher Stephanie King, a research fellow at University of St. Andrews, was entirely new.
“Animals produced copies [of the unique whistles] 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," she told Discovery News.
Supporting research included audio recordings of wild dolphins from Sarasota Bay, Florida, taken between 1984 and 2009. Four captive dolphins were also used as a focus group. Researchers discovered that all of the dolphins exhibited the same trait: each developed its own signature sound, and others called them by it.
They also learned a detail most endearing: dolphins copied the signature sounds of others who they spent the most time with, suggesting that when they copy the sounds, they're actually calling out to their friends.
"We found no evidence for the use of copying in aggression or deception," the study's authors explained. "This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defense of resources."
The growing body of scientific knowledge about the advanced social behavior exhibited by dolphins and whales is so great that some scientists believe cetaceans should be declared "non-human persons," endowed with certain rights. A group based out of Helsinki has even drafted a "Declaration of Rights for Cetaceans," emphasizing the creatures' right to be free from captivity and allowed to exist undisturbed in their natural environment.