"Chimps know how to throw forehand, but can't throw overhand, like a baseball. So usually the rocks they throw have a big arc and people have time to escape," he said.
Rather than covering the chimpanzee compound with rocky Jerusalem soil, it will be covered with a deep layer of fresh soil without the rocky weapons, he said.
"It's kind of embarrassing to be stoned by a chimp," Doron told The Jerusalem Post.
The chimpanzee rock-throwing draws large crowds even though it is a sign the animals are upset, he said. Visitors think it's funny "until they get a rock in the head," Noa Danen, head of the zoo's primate section, told the newspaper.
The money for the two-month refurbishment came from the zoo's endowment fund and was supplemented by a grant from the Tourism Ministry, the paper said.
