January 14, 2011

Dolphins Are Masters Of Imitation

According to Florida researchers, dolphins are able to imitate each other, even blindfolded.

The researchers at the Dolphin Research Center in the Florida Keys said in a study published in the International Journal of Comparative Psychology that their blindfolded dolphin used other senses to figure out what the other dolphin was doing and copy it.

The dolphin is a 7-year-old bottlenose dolphin named Tanner.

The researchers said they hope to conduct further studies to "map the dolphin mind" in order to learn more about the evolution of human cognition.

"Looking at an animal (which is) so far removed from us and yet shares some cognitive abilities, tells us something about us," Dr. Kelly Jaakkola, the center's research director, wrote.

Jaakkola, one of the study's authors, said that primates like chimpanzees can sometimes do it but only humans and dolphins are proficient.

"Most people think, 'Monkey see, monkey do.' It's a complete myth. Dolphins are really good at it. Aside from humans, they're the best at it," Jaakkola wrote.

Tanner had been trained to do a list of tricks like sinking underwater and blowing bubbles, retrieving an object from the lagoon, making a noise like a seagull, and rising and offering a fin to "shake hands" with a person kneeling on the dock.

The researchers gave Tanner a familiar hand signal during their test, asking him to imitate another dolphin.  They then covered his eyes with soft latex eyecups to block his sight.  They used hand signals to ask the other dolphin to do a specific trick, and Tanner imitated the other dolphin within seconds.

They tested him repeatedly on 31 different behaviors in sessions spread over 11 weeks.  He was blindfolded in some sessions and was able to see in others. 

The researchers said that in both cases, he was able to imitate the other dolphin's behavior far more often than would be expected by chance.

He imitated the vocal behavior with 75 percent accuracy, motor behavior with 41 percent accuracy and combined behavior with 50 percent accuracy when he was blindfolded.

Researchers were uncertain whether Tanner figured out what the other dolphin was doing because he recognized the sound that action made or whether he used echolocation, a sensory system bats and dolphins use to determine the direction and distance of objects by how long it takes an echo to return.

"In either case ... he's problem solving," Jaakkola said. "That level of flexibility in imitation has never been seen in a non-human animal."

Jaakkola said that Tanner was chosen for the study because he "really loves playing games" and was comfortable with the eyecups.  He was partnered in the tests with two other males who live in the same lagoon.

Dolphins in the wild are known to imitate each other, with male dolphins doing synchronized displays around females.

Dolphins also copy each other's whistles, which act as names.  Jaakkola said that they call out their own to announce their presence and imitate another's whistle to call to that animal.

They make a variety of other whistles and clicks.  Jaakkola seemed skeptical when asked if perhaps the other dolphins had simply told Tanner which trick to perform.

"Nobody's been able to find any sort of meaning in (their sounds). That doesn't mean it doesn't exist," she wrote.

The Florida researchers want to conduct further studies to see if dolphins can learn new tricks while blindfolded.  Jaakkola said that they hope that by demonstrating dolphins' intelligence, they will give humans more incentive to conserve them.


Image Caption: Tanner is able to copy Kibby's splash without using his eyesight.


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