YOKOHAMA – 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.
He also pays keen attention to feed, noting that the way of feeding needs to take seasonal factors into account. If, for example, a habitat has rainy and dry seasons, feed is in short supply during the dry season, and is abundant and highly nutritious in the rainy season, he said.
If the volume and content of feeding are matched to conditional changes in the seasons, reproductive activities are stimulated, according to Kiryu.
Asked if the preservation of endangered animals at a zoo can prevent them from going extinct, Kiryu said visitors to a zoo, who see a newborn turtle and ask if it belongs to an endangered species, would consider what to do to save it.
Zoos and aquariums engaged in the preservation of certain species can heighten their technological levels by exchanging information with each other, Kiryu added, stressing that such attitudes among ordinary people and experts will contribute to the protection of wild animals.
Born in Tokyo, Kiryu moved to Tokorozawa, Saitama Prefecture, when he was a fourth-grader and lived in the city until he graduated from Nippon Veterinary and Zootechnical College, which is now called Nippon Veterinary and Life Science University. He became fond of raising beetles and other insects when he was a child.
Unable to find a job at a zoo after graduating from the university, Kiryu worked at a pony park in Tokyo for five years. He was then hired by the city of Yokohama as a staff member at the city-run Nogeyama Zoo and was assigned to care for the kagu, an endangered bird species in New Caledonia.
“I learned the ABC’s of breeding animals with the kagu,” Kiryu recalled. “It’s important to re-create a natural cycle for them.”
Kiryu raised a turtle at his home as practice before he took charge of reptiles. He now keeps six species of turtle in a special room.
As his next target, Kiryu hopes to breed the angonoka tortoise endemic to Madagascar, and Japan’s Ryukyu black-breasted leaf turtle.
“There are only 100 to 400 angonoka tortoises in the wild,” Kiryu said. “The one in Nogeyama was brought by police after busting an illegal import.”
“While Nogeyama keeps some 110 turtles and tortoises, half of them came from police,” he added.
Endangered species will become extinct if people seek to obtain them, according to Kiryu.