Harpy Eagle

COMMON NAME: Harpy Eagle

SCIENTIFIC NAME: Harpia harpyja

TYPE: Bird

DIET: Carnivore

GROUP NAME: Convocation

AVERAGE LIFE SPAN IN THE WILD: 25-35 years

SIZE: Wingspan up to 7 feet; Height: 35- 41 inches (females are larger)

WEIGHT: 14-20 lbs (female) 8.5-12 lbs (male)

The harpy eagle is legendary, although few people have seen one in the wild. Early South American explorers named these great birds after harpies, the predatory “frightful, flying creatures with hooked beak and claws” of Greek mythology. This dark gray bird of prey has a very distinctive look, with feathers atop its head that fan into a bold crest when the bird feels threatened. Some smaller gray feathers create a facial disk that may focus sound waves to improve the bird’s hearing, similar to owls. 

Like most eagle species, the female “harpy” is almost twice as large as the male. The harpy eagle's legs can be as thick as a small child's wrist, and its curved, back talons are larger than grizzly bear claws at 5 inches (13 centimeters) long! The harpy may not be the largest bird of prey (that title belongs to the Andean condor), but this extraordinary creature is definitely the heaviest and most powerful of birds.

The deadly talons of a harpy eagle can exert several hundred pounds of pressure (over 50 kilograms), crushing the bones of its prey and instantly killing its victim. A harpy also feeds on opossums, porcupines, young deer, snakes, and iguanas. Heavier prey is taken to a stump or low branch and partially eaten, since it is too heavy to be carried whole to the nest. Most of the harpy’s food is found in the rain forest canopy and understory instead of on the forest floor. The larger females tend to take sloths and monkeys; the smaller, more agile and faster males tend to take more quantities of smaller food items. This increases the pair's odds of eating on a regular basis. 

As parents, they fiercely defend their eggs and young. The mother lays one or two eggs in a clutch, and she only reproduces every two to three years. Both parents incubate eggs, with the female taking most of the responsibility. The first eaglet to hatch gets all the attention and is more likely to survive, while the other egg dies from lack of incubation. So why does the female lay two eggs? The second egg acts as an insurance policy just in case there is something wrong with the first egg. If the first egg fails to hatch, the second egg has a decent chance of hatching, saving the parents the need to start over with a new egg!

The newly hatched chick is all white and doesn’t attain its full adult coloring until its third year. Both parents feed the chick for about 10 months. Harpy eagle chicks are ready to fledge at about five to six months of age, but they usually hang around the nest for over a year, begging a meal from its parents. Maybe returning once in 10 days, the parents provide less and less food, forcing Junior to fend for him or herself. 

Once mature, it is not unusual for chicks to return to nest in their "home tree." Harpies can breed from 5 to 30 years of age and beyond. Given their years of dedicated parenting, a pair may not raise many offspring in a lifetime.

Information on the Harpy Eagle is courtesy of the Sandiego Zoo