Zoos play an increasingly important role in the preservation of wild animals, says Daisuke Kiryu, a keeper of reptiles at Yokohama's Nogeyama Zoo, which is known for successful artificial breeding of turtles designated as endangered species.

"We succeeded in breeding the radiated tortoise and Indian roof turtle for the first time in Japan," Kiryu, 43, said. "Though the spotted pond turtle was privately bred, we were the first to do so in a zoo."

Kiryu studies weather conditions in habitats of turtles, such as Madagascar for the radiated tortoise and India for the Indian roof turtle and spotted pond turtle, and re-creates similar environments for successful breeding.