An environmental group in Japan says that U.S. Air Force test flights are disturbing Golden Eagle nests in northern Japan. The Committee to Protect Akita’s Environment registered the complaint with regional officials on Monday.

The eagles have wingspans up to six and a half feet and are classified as endangered because they are estimated to number fewer than 500. No studies have been done in the Shirakami mountains 280 miles north of Tokyo, but a spokesman for the environmental group and local outdoor guide says that he has seen fewer eagles since jets began flying over the region five years ago.

It is suspected that the jets come from the U.S. base in nearby Misawa. Koichi Kamata, group spokesman for the environmental group, thinks that low flying jets surprise the nesting birds and scare them from their hatchlings, leaving the young to starve.

News compiled by Eric Hansen, Nate Hoogeveen, Jane Maguire, and Mary Catherine O'Connor of Outside magazine.