Bottlenose dolphins have been observed to use distinctive “signature whistles” towards each other, says new research published in the Proceedings of the Royal Society B. That is, dolphins actually call one another by name, a behaviour previously thought to only occur in humans.
Scientists have known that dolphins emit unique whistles that identify them to other dolphins. These can be heard up to 12.4 miles away, depending on the depth of the water and whistle frequency.
Stephanie King, a research fellow at University of St. Andrews, observed that the bottlenose dolphins actually copy the signature whistle of other dolphins when separated from them. This finding, she says in Discovery News, “supports our belief that dolphins copy another animal’s signature whistle when they want to reunite with that specific individual.”
King and her colleagues observed the copying of signature whistles both in wild dolphins around Sarasota Bay in Florida from 1984 to 2009 and in four adult male captive dolphins who live at Florida’s The Sea Aquarium. The keepers had given the latter four the names Calvin, Khyber, Malabar and Ranier but the dolphins were seen to have their own names for each other.
Notably, researchers found that the dolphins used the names for those they are close to, such as a mother to her calf or male dolphin “buddies” to each other. The signature whistles seem to be used to maintain social bonds — just as human language is used — and were not observed in aggressive contexts such as the “matching” of songs that songbirds use to “compete” with other.
Do Dolphins Have a “Language”?
Scientists have been hesitant to use the “l-word” — language — to refer to the sounds that animals other than humans make, says Discovery News. Clearly, the bottlenose dolphins studied by King have “a very complex and sophisticated communication system.”
Dolphins’ sounds include “high frequency echo-location or clicks; and pulse sounds, like noisy, pulsed squawks,” says Lori Marino, an evolutionary neuro-biologist at Emory University who has long studied cetaceans, to Forbes. Her analysis of dolphins’ sounds reveals that these do have “higher-order internal structure or organizational complexity” that is analogous to the grammar and syntax of human language. Marino also notes other aspects of dolphins’ intelligence: they process information and make decisions quickly; they have a ”fluidity” of movement in a group that suggests a highly developed “level of social cohesion” and sense of self; and they show altruism towards other dolphins.
These findings, along with the newfound realization that dolphins have names for each other, offer further evidence for why, as some scientists argue, they should be considered “non-human persons,” in the spirit of the Declaration of Rights for Cetaceans, drafted by a group in Helsinski, Finland.
It also makes one wonder, what do many captive dolphins think about having names like “Flipper” given to them — what if we called them by their names instead and attempted to learn their forms of communication?