Dal piede di porco al Companion Cube

lowenz · **Inviato:** ven ago 19, 2011 9:39 am

Piccoli (?) Freeman evolvono :trollface:

http://news.sciencemag.org/sciencenow/2 ... html?rss=1

Highly social and clever and cooperative with tools, elephants are often near the top of the brainiest creatures list. Now, scientists have added a new talent to elephants' mental repertoire: The ability to solve a problem using insight—that aha! moment when your internal light bulb switches on and you figure out the solution to a puzzle. Previously, only a limited number of species, including certain primates, crows, and parrots were known to have this ability.

Elephants had failed other tests for insightful problem solving because they were asked to use their trunks as we do our hands, says Preston Foerder, the lead author of the new study and a graduate student in comparative psychology at the City University of New York. For example, Foerder first tested whether three Asian elephants (two females and one male) at the Smithsonian National Zoological Park in Washington, D.C., would use sticks placed just outside their enclosure to retrieve food that was out of reach of their trunks. "They didn't have any trouble getting or using the sticks," Foerder says. "They hit them on walls and toys; one even stuck her stick into the opening of her cage door," as if using a crowbar, "but they never used any of these methods to try to get food."

That's when Foerder had an aha! moment of his own. Elephants don't use sticks to get food because they must hold the stick with their trunk, which, despite being able to grasp things, is really an appendage for smelling and eating. When an elephant is asked to hold a stick with its trunk to get food, the trunk loses its primary olfactory function, which is also needed to locate food. "It would be like having an eye in the palm of your hand," Foerder says, "and then being asked to hold a tool and find food. You wouldn't be able to do it."

So instead of asking the elephants to use sticks to reach the food, Foerder and colleagues provided the same three elephants with sturdy, movable objects—a plastic cube and an aluminum tub—that could support their two front feet. All three had been trained to stand on the tub (but not to get food while doing so), and the two females had been trained to push large objects.

The male elephant, a 7-year-old named Kandula, proved to be a boy genius. In the initial six sessions, he made not attempts to get the food. But in the seventh, he suddenly rolled the cube from the middle of the yard to a spot beneath the suspended treat, stood on the cube, and grabbed the prize with his trunk (see video). On his own, he later rolled the cube about 15 meters down a hill and used it to reach flower blossoms hanging from a tree. He also showed that he could generalize his newfound concept, positioning and standing on a tire and a large ball to get the food when the cube wasn't available, Foerder and colleagues report 'today in PLoS One.

The two females (ages 33 and 61) never solved the problem. The 33-year-old, however, who is Kandula's mother, had moved and stood on objects to reach items overhead when she was an adolescent, the zookeepers told Foerder. Foerder says he has no hypothesis to offer for why the females did not figure out the test, saying that it could be due to "sex, age, or just chance."

The study shows that "elephants are right up there with other large-brained animals when it comes to cause-and-effect understanding and mental problem solving," says Frans de Waal, a primatologist at Emory University in Atlanta. "It's not just trial and error, which is what many animals show [in similar tests]," he says, because "the elephant needs to imagine what he needs and then move away from the goal [the hanging treat] to find the tool."

Kandula's talent comes as no surprise to scientists studying elephants in the field. They can "turn on spigots to get water and find their way around human-created barriers" such as electrified fences, says George Wittemyer, a wildlife biologist at Colorado State University, Fort Collins. "Such behaviors must require insight," he says, but these are only observations and not controlled experiments. "It's gratifying to finally have someone carry out the necessary experiments to prove that elephants have the capability of insight," adds elephant expert Joyce Poole, director of ElephantVoices, a nonprofit organization based in Sandefjord, Norway.

Wittemyer and others also regularly see elephants knock down (but not move) trees and stand on them to reach food overhead. "This study makes the first important shift of allowing elephants to use their primary sense of smell without hindrance, and the results are an exciting demonstration of their problem-solving abilities," he says.