The topic of dolphin intelligence is a never-ending source of wonder, and, according to recent studies, the animals appear to know more and remember more than we thought.
A new study from the Dolphin Research Center in Grass Keys, Fla., appears to indicate that dolphins are smart enough to problem solve in much the same way as humans.
Working with a bottlenose dolphin named Tanner, researchers found he was able to imitate behaviors, even when one of his senses was blocked.
“We already knew dolphins imitate other dolphins, but this time we blindfolded Tanner and used humans instead of dolphins to make the movements in the water,” said Dr. Kelly Jaakkola, research director. “What we found is that he imitated the human movements even when he couldn’t see them.
“The news is that he made a choice,” she said. “When imitating another dolphin he could recognize the sound of the behavior, but when we put a person in the water the sound is different and that’s when he would echolocate.”
Echolocation, or bio sonar, involves sending out sounds and then listening to the echoes that return from nearby objects.
“When we tried to mess him up by blindfolding him and putting a human in the water we saw a whole lot more echolocation going on than when he imitated another dolphin. That is evidence to me of problem solving. This is exciting because Tanner could imitate the human without any learning at all, and that is the first time that has been shown in an animal outside of humans.”
While previous research has shown dolphin intelligence, this one indicates reasoning ability, Jaakkola said.
“People are fascinated by dolphins, and the more we can showcase their intelligence, the more people will get excited about taking care of them,” she said. “This type of study gives us more of a window into their minds, which are not like ours. They’re very different from humans and we’re trying to find out how they are intelligent, and what they are good at and not good at doing.”
Dolphins Never Forget a Whistle
People are also fascinated by the concept of dolphins communicating with one another. Another recent study conducted by a graduate student at the University of Chicago, shows not only do they “talk” to each other, but they remember each other for long periods of time.
It has been known since the mid-1960s that dolphins have individual signature whistles, but now researcher Jason Bruck has demonstrated that dolphins can remember each other’s whistles, even when they have been separated for decades.
“I recorded the whistles from 43 animals in the study,” said Bruck, who recently earned his doctorate in comparative human development. “I then played them back to their former tank mates. I also played unfamiliar whistles for them. For the most part they responded by approaching and whistling to the familiar whistles, but not to the unfamiliar whistles.”
In some cases dolphins even whistled back at the recording, signaling their recognition of the source, Bruck said.
Perhaps most fascinating in Ruck’s study were the dolphins’ abilities to remember each other’s signature whistles after long separations, the longest being 20 years and six months. This is the longest social memory ever recorded for a non-human species, according to the study.
“Their individual whistles are sort of like a hybrid of a name and a face would be to us,” Bruck said. “They don’t see each other as well in the water, and because they work at such distances and in murkier environment, they need these individualized whistles to identify each other.”