The Bald Eagle is a large bird, with a body length of 70–102 centimeters, but the females are about 25 percent larger than males.
The adult Bald Eagle has a brown body with a white head and tail, bright yellow irises, and golden taloned feet and hooked beak; juveniles are completely brown except for the yellow feet.
The Bald Eagle is a powerful flier, and soars on thermal convection current. It reaches speeds of 56–70 kilometers per hour when gliding and flapping, and about 48 kilometers per hour while carrying fish.
The Bald Eagle is extremely sensitive to human activity, and is found most commonly in areas free of human trouble.
Its diet consists mainly of fish, but it is an opportunistic feeder. It hunts fish by swooping down and snatching the fish out of the water with its talons (claws on its feet).
They prefer habitats near seacoasts, rivers, large lakes, oceans, and other large bodies of open water with an abundance of fish.
The Bald Eagle builds the largest nest of any North American bird, up to 4 meters deep, 2.5 meters wide, and one tonne in weight.
Their call consists of weak chirping whistles, harsher and shriller from young birds than adults.
Bald Eagles are sexually mature at four or five years of age. When they are old enough to breed, they often return to the area where they were born. It is thought that Bald Eagles mate for life. However, if one member of a pair dies or disappears, the other will choose a new mate.
The average lifespan of Bald Eagles in the wild is around 20 years, with the oldest living to be about 30 years. In captivity, they often live somewhat longer.
In one instance, a captive individual in New York lived for nearly 50 years. As with size, the average lifespan of an eagle population appears to be influenced by its location.