The golden eagle, one of the best-known birds of prey in the Northern Hemisphere, may be facing extinction in Japan as environmental change and low breeding success rates have caused their numbers in the wild to plummet. The Society for Research of Golden Eagle Japan warned Monday that the amount of the Japanese subspecies Aquila chrysaetos japonica have been declining since 1986 and only 500 or so are left living in the wild.
“The biggest issue is the reduced breeding success rate due to a lack of prey,” said Toshiki Ozawa, the research society’s head, according to Kyodo News. He added that poor forest management in areas where the eagles live has led to thick vegetation which made it hard for the birds to spot potential prey such as hares.
The society started monitoring the eagle numbers since 1981 and they reported that the number of breeding pairs have fallen by a third. There were an estimated 340 pairs over 30 years ago, and 99 of the monitored pairs have died or otherwise disappeared from their territories in 2013, according to the group. Of the 241 remaining, just one was found in Kyushu, Japan’s third largest main island in the south, and none were left in Shikoku, the country’s smallest main island also in the south.
Breeding success rates have been steadily declining, down to one in five eggs hatching in 2013, or 20.2 percent. This was a drop from the 50 percent success rates recorded in the 1980s. The birds are prone to abandoning their nests when disturbed.
The public and private sectors have aimed to slow the eagles’ decline by beginning a joint experiment to thin trees in parts of a government-owned forest this fall, according to Kyodo. The Nature Conservation Society of Japan, a non-governmental organization, has collaborated with the Ministry of Agriculture, Forestry and Fisheries to thin out parts of the Akaya Forest, which stretches across 10,000 hectares in Niigata and Gunma prefectures.
While the Japanese golden eagles are facing extinction, its American counterparts’ populations have been stable over the last few decades. Golden eagles are protected in North America by federal laws, and its conservation status is considered to be of “least concern,” according to the International Union for Conservation of Nature. Compared with Japanese numbers, there are some 30,000 golden eagles across the United States.
Other animals in Japan that are also endangered include the Iriomote cat, living exclusively on the island of Iriomote with only about 100 of them remaining, and the Japanese crane, one of the rarest cranes in the world and revered in Japan as a symbol of luck and longevity.