Scientists intrigued at gorilla’s use of tools

AN infant gorilla in a Congo sanctuary is smashing palm nuts between two rocks to extract oil, surprising and intriguing scientists who say they have much to learn about what gorillas can do - and about what that says about evolution.

It had been thought that premeditated use of stones and sticks to accomplish a task like cracking nuts was restricted to humans and the smaller, more agile chimpanzees. Then in late September, keepers at a Dian Fossey Gorilla Fund International sanctuary saw 2½-year-old female gorilla Itebero smashing palm nuts between rocks in the “hammer and anvil” technique, considered among the most complex tool use behaviours.

“This is a surprising finding, given what we know about tool use in gorillas,” Dian Fossey Gorilla Fund primatologist Patrick Mehlman said earlier this month at his Goma office.

Mehlman said the finding indicates complex tool use may not be a trait developed only by humans and chimpanzees, and could have its origins earlier in the evolutionary chain, among ancestors common to both humans and the great apes.

Gottfried Hohmann, an expert on primates at the Max Planck Institute in Leipzig, Germany, told The Associated Press Itebero’s behaviour “means that gorillas have a higher level of understanding of their environment than we thought”.

Itebero has been in the sanctuary for a year, since she was confiscated by local authorities from poachers who had been trying to sell her. Mehlman said he believed Itebero, named for a place near where she was found, started cracking nuts spontaneously and had not been influenced by her time among humans.

Alecia Lilly, a primatologist in Rwanda who has seen Itebero at work, said most learning among gorillas occurs through imitation. But Itebero had no instructor, alone in her sanctuary with her keeper.

“Itebero is remarkably proficient at cracking nuts,” Lilly said. “It takes most chimpanzees many years to reach similar levels of proficiency.”