The behavior was observed in free-roaming dolphin populations as well
For quite some time now, scientists have been analyzing the language that dolphins use to greet and introduce themselves to one another, once they meet. A recent study demonstrated that the behavior occurs naturally, and is not a result of captivity.Until fairly recently, marine biologists had only heard signature whistles – the specific sounds that dolphins make when they meet – in specimens in captivity. What the research demonstrated was that the same signature whistles could be heard in populations living in the wild.
These intelligent creatures do have a language of their own, and we are currently only scratching the surface of what their high-pitch whistles, clicks and pulses mean. What is becoming increasingly obvious is that there are many patterns in the way these sounds are emitted.
One of the most interesting aspects of dolphin language is that each individual has its own unique call, sort of like a name. Whenever two “strangers” meet in the open sea, they greet each other by emitting their signature whistles.
A new research into how these unique calls are used was carried out by scientists at the University of St. Andrews, in the United Kingdom. Experts at the Sea Mammal Research Unit (SMRU) were led by marine biologists Vincent Janik and Nicola Quick.
“Dolphins are comparable to great apes in their cognitive skills, but all we know is what they do in a lab. We wanted to understand how dolphins use their intelligence outside of the tasks that humans set for them,” Janik explains, quoted by Science Now .
In a paper published in the February 28 online issue of the esteemed scientific journal Proceedings of the Royal Society B, the researchers explain how they tracked a group of dolphins known for swimming long distances up and down the eastern coast of Scotland.
The animals were tracked using underwater microphones, digital photography, GPS devices, and unique dorsal fin patterns. Scientists were amazed to see the creatures emit their signature whistles when meeting with another group of dolphins.
Even more interesting, it was found that only one dolphin in each group emitted the sounds. This could point at the existence of a social hierarchy, in which a leader or spokesdolphin exists. At this point, this is only speculation. Researchers say that they will continue their investigation for the foreseeable future.
“Dolphins live in groups that come together and break up, often ending up composed of different individuals. Exchanging signature whistles may be one way they manage these interactions,” says New College of Florida comparative cognitive psychologist Heidi Harley.