For a bird named after a horrid beast from Greek mythology, this raptor of unmatched power and majesty is pretty incredible. The “harpy eagle” was so named because of its resemblance to the chimerical harpy—storm spirits with the face of a woman and body of a bird who carried dead souls to the underworld, Hades.
The harpy eagle is the most powerful bird on Earth. Its first known documentation was in the 10th edition of “Systema Naturae” by Carl Linnaeus in 1758, who dubbed the bird “vultur harpyja” after the mythical beast. As we shall see, its moniker is well deserved.
This bird is big. Bearing slate-black feathers on its upper body and white feathers almost entirely covering its lower half, this avian has been measured at total lengths of 2 feet, 10 inches, to 3 feet, 6 inches; with wingspans from 5 foot, 9 inches, to 7 foot, 4 inches—that’s wider than most NBA players are tall! The raptor has a grip so strong it can crush bone and kill its prey in an instant. It shows no fear around humans and certainly commands our respect.
One of two varieties, the American harpy eagle (the other variety is the New Guinea harpy eagle) inhabits from as far north as Mexico, down through Central and South America, and as far south as Argentina. It is mostly extinct in Central America today and is most commonly found in Brazil where it exists across the nation’s territory.
These impressive eagles inhabit tropical lowland rainforests below elevations of 3,000 feet but have been recorded as high as 6,600 feet, nesting in the upper canopy, the emergent layer of the jungle. They typically do not soar high over the canopy in search of subsistence but usually find their food below. Although they sometimes hunt animals on the ground, it is tree-dwelling mammals that comprise the bulk of this fearsome raptor’s prey.
Harpy eagles typically hunt under forest canopies where dense vegetation casts shadows and creates obstacles for maneuvering. They are great conservers of energy and exhibit patience while hunting; perched high up, they typically scan openings in the brush for prey periodically amid short flights between trees. Occasionally, harpy eagles will fly through the forest to scout for food.
With eyes much larger for their size than other birds, harpy eagles are able to spot their prey from great distances and can observe details as small as 1 inch (2 or 3 centimeters) from nearly 220 yards (200 meters) away. They also use their characteristic facial disk feathers to focus sound waves to their ears, located on the sides of their head, while hunting—much as how we cup our hand to our ear to hear sounds more clearly. Patient hunters, they typically wait for their prey to come to them before performing dive attacks at speeds as fast as 50 miles (80 kilometers) per hour.
As far as prey goes, these raptors like to pick off sloths mostly, but small primates—such as howler monkeys, capuchin monkeys, or saki monkeys—also make up a large portion of their diet. These humongous eagles can carry prey as heavy as their own body weight, sometimes snatching animals as heavy as 18 pounds.
They may swoop in on a sloth or howler monkey and pounce on the animal with great force from above. Their flight muscles are so robust they are known to grab their prey in mid-flight and carry it off without landing—a herculean feat of strength! Moreover, their short, broad wings facilitate the acrobatic capability of flying almost straight up to strike prey from below as well as from above.
Female harpy eagles are much larger than their male counterparts and likewise seek out much larger game. While adult females may weigh between 17 to 18 pounds (7.3 to 8.3 kilograms), adult males are about half that size weighing between 9.7 to 10.6 pounds (4.4 to 4.8 kilograms).
The hearty legs of harpy eagles can be as thick as a child’s wrist, while their curved black talons are long and deadly, with males possessing ones as long as 3.3 inches (8.6 centimeters), and females’ talons measuring a jaw-dropping 4.8 inches (12.3 centimeters)—longer than the claws of a grizzly bear! Moreover, their bone-crushing grip is so forceful, they can exert several hundred pounds of pressure, killing their prey almost instantaneously upon taking hold.
These raptors may be the largest extant eagle in the world today. But with their relatively narrow wingspan, they aren’t the largest bird of prey on Earth—the Andean condor holds that title. Yet the shorter, broader wingspans of harpy eagles serve a particular purpose: increasing their maneuverability in their more confined habitat among the trees. But what they “lack” in size they compensate for in sheer power.
Harpy eagles often nest high in a tree, often in the main fork, as high as between 140 feet (43 meters) to nearly 200 feet (60 meters) above the ground. The kapok tree, one of the tallest trees in South America, is a highly favored nesting choice for these birds, as is the Brazil nut tree.
These eagles construct huge nests, large enough for a man to lay across fully extended. Consisting of a frame made of large sticks and a lining of softer organic material, these nests typically measure four feet deep and five feet wide. Harpy eagles may use a nest for several years, while constantly bringing in fresh twigs to keep the place clean and free of insects and parasites.
Harpy eagle couples mate for life and might have one chick every two to three years. A female lays two eggs, with one serving as a sort of “insurance policy” in case the other fails to hatch or perishes. If that happens, the male will fertilize the second egg giving the couple a fighting chance at hatching an eaglet. The female will incubate the egg, but the male also takes shifts incubating. As one stays, the other leaves to hunt. The female tends to return with larger prey, the male with smaller items but with greater frequency.
Silent hunters usually, the parents call out when in their nest, managing something like a “weak scream.” When the eaglet hatches, the parents chirp rapidly on returning home; the chick becomes increasingly vocal as it matures, releasing “chi, chi, chi, chi” sounds. It will have fledged by 6 months, while the parents may continue feeding it for another 6 to 10 months. The parent eagles make themselves ever scarcer as it grows until it “gets the picture” and forges out to fend for itself. Harpy eagles become mature for breeding at between 4 to 6 years.
It is believed the harpy eagle garnered its mythological moniker because of its signature “facial disk,” comprised of small grey feathers encircling its head, which is said to contribute to a womanly visage. Hence the chimeric female reference. This formidable eagle also possesses a very distinctive crest crowning its head that can fan out when it encounters threats. This feature aptly suits the name given to it by Brazilians: royal hawk.
Although they are not known to prey on humans—yet show no fear of humans either—harpy eagles are said to pick off livestock on rare occasions. It is advised to pay them considerable respect, as one reportedly almost knocked a BBC cameraman unconscious on one occasion. Moreover, with harpy eagle populations diminishing due to hunting and logging, they are considered critically endangered in Mexico and Central America making them all the more worthy of our respect.
Conjuring creatures from Greek mythology, while likewise inspiring Mayan civilization and even a “Harry Potter” character, the harpy eagle is a true wonder of our world. And for now, its awesome beauty continues to live on, inspire, and amaze us.
