Although considered one of the most intelligent animals and possessing the largest brain of any land animal, elephants haven't shown the problem-solving ability of other animals like chimps and ravens. But a recent study conducted at the National Zoo sheds new light on pachyderm problem solving ability, and suggests why previous studies didn't find evidence of elephant insight.
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Elephant's use their trunks as sensory devices. But many previous studies of tool use and problem solving relied on the elephants holding tools in their trunks, as if the trunk were a primate's hand. Putting a tool in its trunk may well have been hampering the elephant's sensory ability, suggested the research led by Preston Foerder and Diana Reiss of the City University of New York.
In the first phase of the experiment, the researchers gave bamboo sticks to three Asian elephants, named Kandula, Shanthi and Ambika. They also placed delicious fruit outside the elephants' cage beyond reach of their trunks. The elephants could have reached the fruit by brandishing the bamboo sticks in their trunks, but none of them did.
A second phase of the experiment involved stringing fruit on bamboo branches from the roof of the elephant's enclosure to a tree in their yard. The tusked test subjects were given both sticks and a large movable cube, which could potentially be used as a stool to reach the fruit.
Kandula, a 7-year-old male, moved the cube and successfully snagged a fruit treat with his trunk. The researchers moved the cube to different places in his yard, and even tried hiding it in a passageway. Kandula was able to find the cube and use it to get the fruit. Kandula had never been trained to move heavy objects like the cube.
Next, the researchers took away the cube and replaced it with a large tractor tire. Once again Kandula was able to move the tire and stand on it with his front feet in order to reach the fruit. In other sessions of the experiment, Kandula stood on a ball to reach the food. He had never been observed to stand on an unstable object like that before. He even tried stacking two small cubes to reach the fruit, but was a few inches shy of the fruit in this attempt.
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The researchers believe that Kandula's behavior may be evidence of an “aha” moment in an elephant. Kandula realized he could use the cube as a tool to enhance his reaching abilities, although he had never been taught to do so.
Elephants have been shown to make extensive use of tools before, but mostly for cleaning their skin. Holding a tool in the trunk causes the sensitive tip to be curled back, hindering the pachyderm's sense of smell and touch. This may well be the reason why only one study has ever observed an elephant using a tool held in the trunk to obtain food, speculate the researchers.
The research was published in the journal PloS One.
IMAGE: Kandula (Mehgan Murphy, Smithsonian’s National Zoo)
Tags: Animal Behavior, Animals, Mammals, Zoo Animals, Zoos and Aquariums
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