Eagle populations also drop every winter when migrating birds head north to mature or to inland rivers to eat spawning salmon. Resident eagles usually live in the islands from October through mid-July, when their young are old enough to fly to salmon spawning rivers. Eagles hatch in late spring and begin to fly at 12 weeks old. Young eagles mature at five or six years old, when their mottled brown feathers are replaced with the familiar brilliant white ones. Eagles mate for life and produce two to three eggs per year.
Couples usually have two nests.
When one nest gets uninhabitable because of vermin and bugs, the eagles move to the other until the old nest airs out. Female eagles are larger than males. An adult female bald eagle can weigh eight or nine pounds and have a wing span of six or seven feet. A female golden eagle can weigh up to 13 pounds. Golden eagles are also popular in the islands.