You might think we humans are the only species to call one another by specific names, and for a long time, the scientific community agreed. Now a new study shows that bottlenose dolphins use specific calls to identify one another, crying out for loved ones when they lose sight of one another. While the calls are whistling noises instead of the words we humans form, they are significant nevertheless. Let’s take a closer look at this intriguing natural phenomenon.
How Dolphins Keep in Touch
The University of St. Andrews Sea Mammal Research Unit conducted a lengthy study on dolphin communications between 1984 and 2009, collecting acoustic data from various bottlenose dolphin populations including those around Sarasota Bay, Florida. They also conducted intense studies on four captive adult dolphins which are housed at The Seas Aquarium, which is also located in Florida.
Earlier studies found that bottlenose dolphins have signature whistles they use to announce or name themselves. They use these whistles to introduce themselves to others. The new study’s findings show that these dolphins also whistle the names of other dolphins they are familiar with - particularly when those dolphins are close companions.
“Animals produced copies (of the 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,” said lead researcher Stephanie King.
Dolphins are highly social and have complex interactions with one another. They depend on close interactions for mating, hunting, and defending themselves as well as their pods. Most experts agree that when dolphins form social relationships, those friendships and partnerships are long-lasting, much like those we humans often experience and tend to prefer. And while individuals know and greet each other, large groups of dolphins often meet up and engage in complex greeting ceremonies that seem to suggest the renewal of old relationships.
Besides whistling and squeaking to one another, dolphins engage in close body contact; they often swim along next to one another, touching fins in a way that seems to mimic humans or other primates holding hands. Dolphins have also been seen rubbing their pectoral fins together in a way that looks a lot like a handshake.
While the animals must be at close range to engage in these behaviors, they can hear audible communications for distances as far as about 20 kilometers (12.4 miles) depending on various factors such as water depth and whistle pitch or frequency.
This intriguing study on dolphin communication has not yet come to a close. Now, King and her colleagues are using sound experiments to see how free-ranging dolphins in the wild react when they hear a copy of their own signature whistle. While researchers are hesitant to use the word “language” to refer to non-human communications, it is clear that bottlenose dolphins have complex and highly sophisticated methods for communicating; and it’s likely that once other dolphin species are studied closely, similar findings will emerge. We look forward to hearing about and sharing the results of future studies on cetacean communications.