An endangered short-tailed albatross has laid an egg for the first time at Midway Atoll, the U.S. Fish and Wildlife Service has announced.

If the egg hatches in the middle of next month, the island might become the third breeding ground for the birds, joining Tokyo’s Torishima island, part of the Izu Islands, and the Senkaku Islands.

The nest is at Midway’s Eastern Island, about 1,370 miles northwest of Honolulu. Off-limits to the general public, it is administered by the wildlife service as a nature reserve.

The mother and father bird have been taking turns warming the egg. Their leg rings show both birds were born on Torishima and that the male left his birth nest in 1987 and the female left hers in 2003.

The Oceanic Wildlife Society, a Japanese nonprofit organization that protects mainly marine wildlife, and other entities placed 16 decoys on Midway Atoll in 2000 to encourage the birds to form a new colony.

Environmentalists have been playing bird cries recorded on Torishima.