Washington, Sep 29 (Inditop.com) Simians may outsmart spotted hyenas but when it comes to cooperation and problem solving, hyenas easily beat chimps hands down, says a new study.
Captive pairs of spotted hyenas that needed to tug two ropes in unison to earn a food reward, cooperated successfully and learned the manoeuvres quickly with no training. Assigned a similar task, chimps and other primates often require extensive training, said Christine Drea, evolutionary anthropologist at Duke University.
She performed these experiments in the mid-1990s but struggled to find a journal that was interested in non-primate social cognition. “No one wanted anything but primate cognition studies back then,” Drea said.
“But what this study shows is that spotted hyenas are more adept at these sorts of cooperation and problem-solving studies in the lab than chimps are. There is a natural parallel of working together for food in the laboratory and group hunting in the wild,” she said.
Drea and co-author Allisa N. Carter of the University of California at Berkeley (UC-B) designed a series of food-reward tasks that modelled group hunting strategies in order to single out the cognitive (intelligence) aspects of cooperative problem solving.
Spotted hyena pairs at the Field Station for the Study of Behaviour, Ecology and Reproduction in UC-B, were brought into a large pen where they were confronted with a choice between two identical platforms 10 feet above the ground.
Two ropes dangled from each platform. When both ropes on a platform were pulled down hard in unison — a similar action to bringing down large prey — a trap door opened and spilled bone chips and a sticky meatball.
The double-rope design prevented a hyena from solving the task alone, and the choice between two platforms ensured that a pair would not solve either task by chance, said a Duke release.
The first experiment sought to determine if three pairs of captive hyenas could solve the task without training. “The first pair walked in to the pen and figured it out in less than two minutes,” Drea said. “My jaw literally dropped.”
Drea and Carter studied the actions of 13 combinations of hyena pairs and found that they synchronised their timing on the ropes, revealing that the animals understood the ropes must be tugged in unison.
“Their non-verbal communication included matching gazes and following one another. In the wild, they use a vocalisation called a whoop when they are hunting together,” said Drea.
These findings are slated for publication in the October issue of Animal Behaviour.
