Adog may be man’s best friend, but dolphins can imitate human actions, and even how they solve problems.
When a dolphin has one of its senses blocked, it can use other senses to mimic a human’s movements, according to a recent study.
A bottlenose dolphin named Tanner was blindfolded and instructed to copy the actions of a trainer in the water with him. When Tanner wasn’t able to use sight to figure out the movement, he switched to another technique: He would emit sounds, listen to the echo and interpret the resulting sound waves. This process — known as echolocation — allowed Tanner to mimic movements by the trainer, such as spinning in the water.
The study, conducted at the Dolphin Research Center in the Florida Keys, expands on earlier studies looking at how dolphins are able to imitate other dolphins while blindfolded. To see whether a change in sound would affect their imitation, researchers used humans instead of dolphins to make the movements in the water.
Kelly Jaakkola, research director of the marine mammal center, said researchers were surprised by Tanner’s use of echolocation.
“He outsmarted us,” Jaakkola said.
She explained that dolphins must decide when to use echolocation, “and that’s problem-solving.”
Janet Mann, a professor of biology and psychology at Georgetown University in Washington who was not involved in the study, said the results were not surprising because that’s how dolphins act in the ocean.
“Of course they would use their echolocation to get more information. Dolphins have to solve problems all the time in the wild,” she said.
During a recent demonstration in a Florida lagoon, trainer Emily Guarino got Tanner’s attention by asking, “Are you ready to play? Let’s play the research game.”
Guarino indicated to Tanner that he was supposed to imitate, and she placed latex eyecups over each of the dolphin’s eyes. Another trainer in the water was then shown a clipboard with a written behavior to perform. That trainer began to spin in the water with his arms wrapped across his shoulders. Tanner then did a similar spin.
For the study, researchers tested a dozen behaviors that Tanner already knew, including bobbing up and down, blowing bubbles underwater and swimming like a shark with the tail — or feet — moving side to side. Each behavior was tested twice, with and without the blindfold, as researchers recorded echolocation sounds underwater.
Tanner was just as accurate at imitating a human — blindfolded or not — as he was at imitating another dolphin, researchers found.
That kind of flexibility with imitation is more commonly associated with humans. But humans and dolphins are separated by about 90 million years of evolution, and the sets of imitation skills probably evolved separately. So exploring imitation in those species “has the potential to give us clues into why imitation ever evolved at all,” Jaakkola said.
Further testing is needed to see if other dolphins can imitate as well as Tanner.
“But we have no reason to believe that this dolphin was just an Einstein dolphin that did this,” she said.