Description The word "bald" originally meant "white-headed." The scientific name, Haliaeetus leucocephalus, means "white-headed sea eagle" in Latin. Male and female bald eagles are identical in color. The distinctive white head and tail mark an adult, a sexually mature 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. With up to a 7-foot wingspan, the bald eagle is one of the largest birds of prey in the world. Adults are 3 to 3 1/2 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. 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! Immature bald eagles often are confused with golden eagles, which also are nearly solid brown. One characteristic that sets the two species apart is the legs. The bald eagles 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."