Bald Eagle - Falconiformes Accipitridae Haliaeetus leucocephalus
Identification & Description:
• Very large raptor.
• Adults unmistakable with brown body and white head and tail.
• Sexes similar
• Very large, broad-winged, broad-tailed hawk
• Rounded long broad wings held flat while soaring.
• Bill large and hooked.
• Plucks fish from water with talons
• Size: 71-96 cm (28-38 in)
• Wingspan: 204 cm (80 in)
• Weight: 3000-6300 g (105.9-222.39 ounces)
• White head and upper neck
• White tail
• Dark brown body plumage
• Yellow bill
• Dark bill and dark cere
• Dark brown body plumage, including head and tail
• Variable amounts of white on underwing coverts, belly, and back
• White head and tail, and dark underwings are gradually acquired in four years
Life History Groupings
• Migration Status: Short distance migrant
• Breeding Habitat: Wetland-open water
• Length of Incubation: 34-36 days
• Days to Fledge:70-98
• Number of Broods:1
Lesser Quantities of: Small Mammals & Birds
• Humans are the most important source of mortality for this threatened species.
• The Bald Eagle isn't bald. The use of "bald" in its name is actually a shortening of the word "piebald," which describes something that is spotted or patchy, especially in black and white. Because the Bald Eagle has a dark brown body and a white head and tail, piebald is an apt description.
• Bald Eagles occasionally hunt cooperatively, with one individual flushing prey towards another.
• The immature Bald Eagle has a prolonged period of exploration lasting for four years. Some young from Florida have wandered north to Michigan, and birds from California have reached Alaska.
Pygargue à tête blanche (French)
Águila cabeza blanca (Spanish)
Male Bald Eagles generally measure a full 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 of sticks in the tops of large trees near rivers, lakes, marshes, or other wetland areas. Nests are often re-used 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.
Bald Eagles normally lay two to three eggs once a year. 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.
Bald Eagles have few natural enemies. But in general they need an environment of quiet isolation; tall, mature trees; and clean waters. Those conditions have unfortunately changed over much of the Bald Eagle's former habitat.
Meanwhile, these birds of prey became prey themselves. Although primarily fish and carrion eaters, Bald Eagles and other raptors were seen as marauders that killed chickens, lambs, and other domestic livestock. As a consequence, large numbers were shot by farmers, ranchers, and others.
The greatest threat to the Bald Eagle's existence arose from the widespread use of DDT and other pesticides after World War II. DDT was sprayed on croplands throughout the country and its residues washed into lakes and streams. There, they were absorbed by aquatic plants and small animals that were eaten by fish. The contaminated fish, in turn, were consumed by Bald Eagles.
The chemical interfered with the Bald Eagle's ability to develop strong shells for its eggs. As a result, Bald Eagles and many other bird species began laying eggs with shells so thin they often broke during incubation or otherwise failed to hatch. Their reproduction disrupted, Bald Eagle populations plummeted. As the dangers of DDT became known, in large part due to Rachel Carson's famous book Silent Spring, this chemical was banned for most uses in the U.S. and Canada in 1972.
In addition to the adverse effects of DDT, Bald Eagles also died from lead poisoning as a result of feeding on hunter-killed or crippled waterfowl containing lead shot and from lead shot that was inadvertently ingested by the waterfowl. (In 1991, a 5- year program to phase out the use of lead shot for waterfowl hunting was completed by the U.S. Fish and Wildlife Service.)