The harpy eagle is a large bird of prey native to Central and South America. Harpia harpyja is the scientific name for the species. A large and distinctive crest on the bird's head, along with its extremely powerful build and long talons make it among the most striking species of eagles. It prefers unbroken stretches of rainforest where it lives above the canopy and hunts in the upper stories rather than on the ground. Monkeys and sloths, along with larger reptiles, are its most common prey.
A female harpy eagle may be twice as big as a male, weighing 14 to 20 pounds (about 6 to 9 kg) to the male's 8.5 to 12 pounds (about 4 to 5.5 kg.) Adults are usually 35 to 41 inches (about 89 to 104 cm) long and have a wingspan up to 7 feet (about 2.1 m.) The harpy eagle is powerfully built, with unusually thick legs and talons up to 5 inches (13 cm) long. Both sexes display their intimidating crest of dark feathers when alert or hostile.
The adult harpy eagle as a dark gray to black back and wings with a light gray to white lower body. Its neck and upper chest are also dark and the feathers on the head shade from dark on the back to white on the face. The bird has a facial disk of feathers that stand up around its eyes,as owls do, to help channel sound to its ears. Light-gray feathered legs end in large yellow feet.
A harpy eagle pair mates for life. They raise only one chick every two to three years. A pair often has two eggs, but after the first successfully hatches, they stop incubating the second. Breeding season is in April and May, and the parents incubate the eggs for 53 to 56 days.
The chick is fledged at 6 to 7 months but stays in the nest for as long as 10 months. It will remain in the parents' territory for as long as a year or more. During that time the parents gradually taper off feedings and it learns to hunt for itself.
Each harpy eagle pair needs a territory of about 11.5 square miles (about 30 square km) to hunt in. The birds are territorial and will chase other harpy eagles out of that area. Harpy eagles have been known to live as long as 25 to 35 years in the wild.