Nearly extinct seabird confirmed to be breeding on Japanese island
Endangered Bryan’s shearwater seabirds have been seen breeding on one of the Ogasawara Islands in Tokyo, the Forestry and Forest Products Research Institute (FFPRI) has announced.
“The area may be the sole habitat (in the world) for the species,” said Kazuto Kawakami, a senior researcher at the Tsukuba, Ibaraki Prefecture-based FFPRI.
The discovery is expected to help reveal the life of the birds, which has been shrouded in mystery. Only eight Bryan’s shearwater have been seen alive.
Bryan’s shearwater are about 27 centimeters to 30 centimeters long, and weigh about 130 to 150 grams. The upper half of their body is black, except for around the eyes. The bird’s lower half is white and its legs are blue.
The species was believed to have become extinct after sightings of a single bird on the Midway Islands in 1963 and 1991, respectively.
In 2012, the Tsukuba institute and other research organizations announced they had confirmed six live Bryan’s shearwater on the Ogasawara Islands from 1997 to 2011, giving the species the Japanese name Ogasawara himemizunagidori.
After that, however, there were no new reports of the bird, which is listed as an endangered species on the red lists of the Environment Ministry and the International Union for the Conservation of Nature and Natural Resources.
This year, the FFPRI and the Institute of Boninology in the village of Ogasawara conducted research in a three-hectare area of the uninhabited Higashijima island from the night of Feb. 25 to the morning of Feb. 26.
Searching for the bird’s highpitched chirp sound, the research team found 10 Bryan’s shearwaters and captured four, measuring their length and other physical sizes. The birds were released immediately afterward.
One of the 10 birds was sitting on eggs in an underground nest in a state-owned forest, home to such indigenous plants as Ogasawara susuki silver grass and takonoki screw pine.
The Forestry Agency plans to start work in the area to remove ginnemu white pontiac — an alien plant that could make lands unsuitable for the endangered bird’s reproduction — as it has been causing environmental destruction on the island.
“We should say Bryan’s shearwater is on the verge of extinction, as we could find only 10 in the three-hectare area,” Kawakami said. “We want to conduct research (on the species) on other islands, too.”