When a flightless bird was caught on June 28, 1981, researchers who had set the trap were delighted to find it held just what they had been looking for.

The discovery of a new species of bird, the Okinawa rail, took place 40 years ago in June. It remains an endangered species.

Named the Okinawa rail, the bird was described as a new species in a paper published later that year.

Four decades later, researchers involved have looked back on the excitement of the time, still vividly recalling the emotions they felt when the bird was captured.

“When I saw the bird in the trap, I felt a sense of relief and accomplishment,” said Kiyoaki Ozaki, deputy director of the Yamashina Institute for Ornithology in Chiba Prefecture, who conducted the research back in 1981. “I was surprised it was living so close to human settlements but had never been identified.

“Even after 40 years, there are still many unknown aspects of its habits, and further research is needed.”

Before it was named the Okinawa rail, the flightless bird was known as yamadui (mountain bird) and agachi (flustered fellow) among local residents in the local dialect. Those who caught the bird now highlight the need to protect its natural environment in the northern part of Okinawa’s main island.

“I often saw the birds in the mountains; I didn’t realize that it was a new species,” Morio Oshiro, 84, a forestry worker in Kunigami village, said with a laugh.

In the early 1970s, Tetsuo Tomori, 88, who conducted wildlife research as a biology teacher at Nago High School at the time, received a report that there was a Japanese pheasant in the mountains of Kunigami.

As Tomori continued his research, he learned of the existence of the yamadui, and visualized what it looked like. A few years later, he saw the bird in the village with his own eyes, running in front of him.

In 1975, researchers at the Yamashina Institute for Ornithology, which was conducting annual surveys of migratory birds in Okinawa, also heard rumors of the bird. Ozaki recalled that he was skeptical at first, wondering if it really existed in a place like Okinawa, which was not uncharted land.

However, during a survey conducted over a few days in 1980, he confirmed the existence of an unknown species of rail at Mount Yonaha in Kunigami. Ozaki immediately drew sketches of the bird and, in 1981, embarked on a long-term survey to capture it.

The base camp for the survey team was a shed on the farm of Koji Onishi, 70, in Kunigami. The team set traps and checked them every few hours. Ten days later on the morning of June 28, a young bird the team had been chasing was finally caught in a trap he had set halfway up a mountain.

Shortly before that, Tomori had obtained the carcass of another Okinawa rail from an acquaintance.

“I still remember the excitement I felt when I opened the package wrapped in newspaper,” he recalled. “I was convinced that it was definitely a new species.”

Tomori stuffed the carcass and offered it to the institute so that it could be used in an announcement of the new species.

One week after they captured the young Okinawa rail, researchers also succeeded in capturing an adult bird. Ozaki and the other team members brought the adult bird to the Okuma Elementary School gymnasium to see if it could fly. The bird ran quickly for about 10 minutes, but never once tried to get airborne.

After that, the research team went to Onishi’s shed to come up with a name for the bird. Over glasses of awamori liquor, some suggested, “How about ‘Okinawa fumiru‘ because it looks like a fumiru (the local name for waterhen)?”

But Onishi suggested that they add “yambaru,” which refers to the northern area of Okinawa thick with mountains and forests, to the name. Yambaru kuina is the Japanese word for the Okinawa rail.

“I couldn’t really sense the importance of the moment when I captured it. But now it’s a bird of the world,” he said with a smile.

“The number of Okinawa rails has decreased significantly due to mongooses and cats,” Ozaki stressed. “Conservation measures have been taken and their numbers are now recovering, but they are still in danger of extinction. Protecting the earthworms and snails that feed them, as well as the entire forest ecosystem, will help protect the Okinawa rail, a symbol of biodiversity.”