Bald eagles are sexually mature at age 4 or 5, and capable of breeding for about 20 years. Bald eagles often put on elaborate displays during courtship, chasing each other and diving dramatically. They even do cartwheels! Bald eagles will lock their talons together in a freefall from high in the air, "cartwheeling" downward, only to release each other before hitting the ground. Once mated, bald eagles are paired up for life, though a surviving bird will seek a new partner if the original partner dies. The bald eagle lays up to three dull white eggs annually, incubating them for about 35 days. Eggs are laid and hatched a few days apart to give the first chick an opportunity to grow without competition for food. Subsequent chicks are at a disadvantage, as the older, larger chicks will eat first. Younger chicks sometimes die for lack of food, or are occasionally killed by older siblings. Newly hatched chicks, or eaglets, are covered in gray down, which is replaced by feathers between the fourth and fifth week. The eaglets raised in the Vermont hacking project arrive just after the "downy" stage. The first two birds weighed about 6 and 8 pounds! The male provides most of the food during the brooding period, while the female protects the nest and eaglets from predators, wind, rain, and sun. During the hacking process, volunteers provide food for the eaglets without being seen, so the birds donšt associate food with humans. Nests are made from sticks and twigs, with a center lined with moss, feathers and other soft materials, and built in large, live trees. Most often, the nests are built high up in the tree, but at least several feet from the top. The hack boxes are designed to mimic a natural nest while simultaneously providing protection from adverse weather and predators. There is a nest inside the hack box. The nests are the biggest of any bird in the United States - generally up to 6 or 7 feet across and 3 feet tall. They are used year after year. Bald eagles will sometimes evict other birds from their nests and move in. Bald eagles are sensitive to human disturbance, especially during the breeding season. People should stay at least a quarter-mile away from any nesting bald eagle. To learn more about the characteristics of the bald eagle, click on any of the photos or links below. Gender differences || Eyesight || Wings, flight & migration Life stages || Why "bald" eagles? || Nesting & breeding Habitat & Threats || Predators & Predation Terms of Use - Copyright 2009 Central Vermont Public Service Copyright photos CVPS, Floyd Scholz U.S. Fish & Wildlife Service and Vermont Department of Fish & Wildlife Web related issues