The True Harpy

The Harpy Eagle (Harpia harpyja) is a true beast of the sky 

that only a handful of people will ever see in the wild. 

South American explorers named these great birds after 

harpies, the predatory “frightful, flying creatures with 

hooked beak and claws,” of Greek mythology.

Head shot of an adult Harpy Eagle (photo: wikipedia)

This mostly dark gray bird of prey has an extremely distinctive look, 

having feathers atop its head that fan into a bold crest when the bird 

feels threatened.  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 Eagle can be almost twice 

as large as the male.  Female’s can average in weight from 13-20 lbs., 

whereas the average weight for a female Bald Eagle is approximately 

12 lbs.   The Harpy Eagle's leg could be as thick as a man's wrist, and 

its back talons are larger than bear claws at 5 inches long.  The Harpy 

Eagle is one of the world’s 2 or 3 largest raptors, and is a true apex 

predator.

Harpy Eagle in flight (photo: wikipedia)

Harpy Eagles range from Mexico to Argentina and live in forests. 

Not having a massive wingspan (but it still can reach 6 feet across), 

Harpies fly through their forest home with great agility.

For nesting, Harpies favor silk-cotton trees and usually build nests 

90 to 140 feet above the ground.  They like to use trees that have 

widely spaced branches for a clear flight path to and from the nest. 

Harpies use large sticks to create the nest’s huge frame and line it 

with softer greens, seedpods, and animal fur to make it warm and 

comfortable.  A Harpy nest measures about 4 feet thick and 5 feet 

across--big enough for a person to lie across.  Once built, an eagle 

pair may reuse and remodel the same nest for many years.

Harpies are great at saving needed energy.  You will rarely see a 

Harpy Eagle flying over the top of rain forests.  Instead, the powerful 

Harpy flies below the forest canopy and uses its great talons to snatch 

up monkeys and sloths that can weigh up to about 17 pounds.  A 

Harpy is capable, in a serious chase, of reaching speeds around 50 

miles per hour.  It dives down at its prey and snatches it with 

outstretched feet.  Its short, broad wings help the Harpy fly almost 

straight up, so it can attack prey from below and above.

Harpies are ambush predators—perching in a tree waiting for prey like this 

male Harpy (photo: wikipedia)

The Harpy Eagle can turn its head to get a better look at its prey. 

The bird perches silently up to 23 hours in a tree, waiting to catch 

unsuspecting prey.  It has amazing vision and can see something 

smaller than 1 inch in size from almost 220 yards away.

A Harpy's feet are massive. This photo does not do them justice.... 

(photo: wikipedia….

….the back talons are longer than this bear’s claws 

(photo: Gay Schroer)

The deadly talons of a Harpy Eagle can exert several hundred 

pounds of pressure, crushing the bones of its prey and instantly 

ending its victim.  A Harpy also feeds on opossums, porcupines, 

small deer, snakes, and lizards.  Larger prey is taken to a stump or 

low branch and partially eaten, because many times prey is too 

heavy to carry whole to the nest.  A lot of the Harpy’s food is found 

in the rain forest canopy and understory instead of on the forest 

floor.  The bigger females tend to take sloths and monkeys; the 

smaller, more agile and faster males tend to take more quantities 

of smaller food.  This increases the pair’s odds of eating on a regular 

basis.

All in all, the Harpy Eagle has to be one of the most powerful and 

impressive creatures in the sky.

Submitted by Ian Wright, World Bird Sanctuary Naturalist