The American Bald Eagle is truly an all-American bird — it is the only eagle unique to North America. It ranges over most of the continent, from the northern reaches of Alaska and Canada down to northern Mexico. The bald eagle, our national symbol, is listed as endangered under the Endangered Species Act in 43 of the lower 48 states and listed as threatened in Michigan, Minnesota, Oregon, Washington, and Wisconsin. (There are about 40,000 bald eagles in Alaska and none in Hawaii.) However, bald eagles have improved greatly in numbers, productivity, and security in recent years.
Male bald eagles generally measure 3 feet from head to tail, weigh 7 to 10 pounds, and have a wingspan of about 6 1/2 feet. Females are larger, some reaching 14 pounds and having a wingspan of up to 8 feet. This striking raptor has large, pale eyes; a powerful yellow beak; and great, black talons. The distinctive white head and tail feathers appear only after the bird is 4 to 5 years old.
Bald eagles are believed to live 30 years or longer in the wild, and even longer in captivity. They mate for life and build huge nests in the tops of large trees near rivers, lakes, marshes, or other wetland areas. American Bald Eagle nests are often reused year after year. With additions to the nests made annually, some may reach 10 feet across and weigh as much as 2,000 pounds. Although bald eagles may range over great distances, they usually return to nest within 100 miles of where they were raised.
American Bald Eagles normally lay two to three eggs once a year and the eggs hatch after about 35 days. The young eagles are flying within 3 months and are on their own about a month later. However, disease, lack of food, bad weather, or human interference can kill many eaglets; sometimes only about half will survive their first year.
The staple of most bald eagle diets is fish, but they will feed on almost anything they can catch, including ducks, rodents, snakes, and carrion. In winter, northern birds migrate south and gather in large numbers near open water areas where fish or other prey are plentiful.