Northern Prairie Wildlife Research Center
Size: With a 6.5- to 7-foot wingspan, the bald eagle is one of the largest birds of prey in the world. Adults are 3-3.5 feet tall and weigh 8 to 15 pounds. Like many predatory birds, the female is larger than the male, but size cannot be used conclusively for identification.
Color: Male and female bald eagles are identical in color. The distinctive white head and tail mark an adult, a sexually nature bird that is at least 4 to 5 years old. Younger individuals are almost solid brown, although a general mottling in the body feathers and a light coloration in the head and tail develop in older immatures. Both young and adult bald eagles have yellow legs. The young birds have a dark beak and black eyes, both of which turn bright yellow as they become adults.
Similar Species: Immature bald eagles often are confused with golden eagles, which are also nearly solid brown. One characteristic that sets the two species apart is the leg. The bald eagle's legs are naked, while golden eagles have feathers all the way down to the talons. In flight, bald eagles soar with flat wings while golden eagles soar with their wings raised in a slight "V."
Foods: Fish comprise the bulk of the bald eagle's diet. In midwinter, dead or crippled waterfowl and other wildlife become important food sources.
Prey Size: The weight of prey items varies from tiny fish to larger carrion. An eagle would have difficulty carrying anything greater than its own weight, and eagle prey are most frequently within the 3- to 5-pound range.
Nest: Nests usually are built near the top of a large tree. Enlarged annually, a bald eagle nest can become the largest of any North American bird. The record nest measured 20 feet deep, 10 feet wide and weighed two tons!
Eggs: Bald eagles lay two (rarely three) white eggs each year. Both parents incubate the eggs for a 35-day period. Young: At 10 to 12 weeks of age, eaglets are fully feathered, nearly full grown and can fly from the nest.
Longevity: Although the life expectancy of wild eagles may 30 years, some have lived 50 years in captivity.
Eyesight: The bald eagle's eyesight is 5 to 6 times sharper an a human's.
Speed: Eagles fly 20 to 60 miles per hour in normal flight and dive at more than 100 miles an hour.