The Surprising Skill Dolphins Have in Common With Humans

Fact: Dolphins call each other by name. Question: What do they call Taiji fishermen?

A bottlenose dolphin blows underwater bubbles in the waters off Curacao. (Photo: Getty Images)

David Kirby has been a professional journalist for 25 years. His third book, 'Death at Seaworld,' was published in 2012.

If you were a dolphin, what would your name be?

It may sound like a pointless question from a Barbara Walters Oscar-night special, but it’s actually a serious line of inquiry explored by scientists. What they found was remarkable: Bottlenose dolphins not only have individual “names,” technically signature whistles they use to identify themselves, but they also copy the whistles of companions and family members likely as a means of calling out to those specific animals.

Scientists have long known that animals learn how to copy common sounds made by their own group, whether a flock of birds or a pod of whales. But the signature whistle of bottlenose dolphins “stands out from these examples in that it seems to be more individually specific,” writes lead author Stephanie L. King in a study published in the current issue of Proceedings of the Royal Society B.

Bottlenose dolphins possess an impressive repertoire of whistles and pulsating sounds they use to communicate with each other, although the question of whether they employ “words” and “language” is highly controversial.

Still, anyone who has studied and observed wild dolphins, including killer whales, knows how well they coordinate their movements, whether resting, foraging, playing or travelling.

Male bottlenose, for example, form their own little groups that band together for companionship, common defense and general pack-like marauding.

But how do they recognize one another, and how do they find each other if separated in the open sea? Dolphins have no sense of smell, and though their eyesight is good, I doubt they can visually identify every individual in their group from a distance, especially at night or in murky water.

That’s where the whistles come in: Bottlenose dolphins not only recognize the signature sounds of others, they can use them to call out to close associates as well.

“The signature whistle tends to be the most commonly used whistle in each individual’s repertoire accounting for around 50 per cent of all whistles produced by animals in the wild,” the study said. “Bottlenose dolphins are, however, able to learn new sounds throughout their lives, and [group members] occasionally imitate the signature whistles of others. Thus, one animal’s signature whistle can form a minor part of another animal’s vocal repertoire as a result of copying…allowing it to be a label for that particular individual when copied.”

Copying was almost always limited to close associates “such as mother–calf pairs and male alliances during separation,” the study said. The dolphins never called out to each other in aggression, nor did they employ the skill for deception.

“Deceptive signature whistle copying by male dolphins could allow them to gain access to females guarded by other males or to avoid directed aggression from a male alliance,” according to the paper.” However, “It appears that copies are sufficiently rare to allow for such a use without jeopardizing the reliability of signature whistles as identity signals.”

In other words, males in one pack don’t want to blow their cover around males in a rival pack.

The communication among associates was, instead, consistently friendly in nature. “This use of vocal copying is similar to its use in human language,” the study noted, “where the maintenance of social bonds appears to be more important than the immediate defense of resources.”

This discovery only deepens our understanding of and fascination with the uncanny intelligence of animals. Dolphins have large, highly evolved brains, they possess a deep sense of compassion, are capable of logical deduction, abstract understanding and tool use, and they can recognize themselves in the mirror—a feat that only elephants, great apes and people over the age of two can perform.

And now we know they call out to specific friends and family members, who answer them back by name.

To me, the more we learn about dolphin intelligence, the more unethical it becomes to hunt, kill and keep them in captivity. The horror of the dolphin drive, slaughter and abduction that goes on in Taiji, Japan, for example, comes into even more agonizing relief when you realize these animals are calling out to each other, individually, in pain, panic and desperation. Perhaps they are even saying “goodbye.”

Once in captivity, some dolphins copy the signature of others, but not as much as bonded wild dolphins.

But even so, if these captive, sentient animals can call out to each other by name, might they be exchanging other types of messages? Imagine what they might be “saying” about their predicament in a concrete pool surrounded by gawking tourists.

Somewhat ironically, this study, which provides even more evidence that captivity is just plain wrong for animals of such intellectual caliber, was conducted using captive and “briefly captured” dolphins, all of them in Florida.

Data in the field were collected over time from bottlenose dolphins taken from Sarasota Bay and then released. Captive dolphin data came from four males (Calvin, Khyber, Malabar and Ranier) held at Disney’s The Seas Aquarium in Lake Buena Vista.  

It’s not clear if other dolphin species can copy the signature whistle of close associates, though it wouldn’t surprise me at all. I have always wondered, for example, how Antarctic killer whales coordinate their attacks on seals resting atop ice floes. Apparently at the command of a single orca, likely the matriarch, they line up and charge the ice, creating a wave that sweeps the seal into the sea, where one killer whale is waiting, mouth agape, for lunch. 

I wondered how they decide who will catch the next seal, and how that information is transmitted to that member of the pod.

So just think about this: We humans are holding captive creatures who can address each other by individual name. In light of that knowledge, to me, cetacean captivity becomes as exotic and grotesque a proposition as aliens keeping people on display at a “humanarium” on some distant planet.

You don’t have to commit the scientific sin of anthropomorphism to understand that some animals are just too much like us to be put on display like storefront mannequins. The question then is, why do we still need captive dolphins to learn that they are too intelligent for captivity? 

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