Bio Facts: Eagle, Harpy
Mexico to northern Argentina and southern Brazil.
Tropical lowland rainforests in the upper (emergent) canopy layer.
The upper side is covered with slate black feathers and the underside with white; a black band extends across the chest up to the neck. The head is pale grey, and is crowned with a double crest. The plumage of male and female is identical. The talons are up to 5 in. (13 cm) long. Females typically weigh 14 – 20 lbs. (6.5 - 9 kg). Males weigh about 8.5 – 12 lbs. (3.8 - 5.4 kg). Height ranges 2.94 – 3.43 ft (89-105 cm) and wingspans approximately 6’7” (200 cm).
In the wild, they eat tree-dwelling mammals such as monkeys, coatis, opossums and sloths and occasionally birds; in the Zoo they are fed a variety of prey items such as rats, rabbits, and chicken as well as a nutritionally balanced meat product.
IUCN – Lower Risk, Near Threatened; CITES – Appendix I and II
This species is an actively hunting carnivore. This bird prefers large expanses of uninterrupted forest, but will hunt in open areas adjacent to forest patches. Its main prey is tree-dwelling mammals such as monkeys, coatis, and sloths; it may also attack other bird species such as macaws. The talons are extremely powerful and assist with suppressing prey. The Harpy Eagle can exert a pressure of 530lbf/sq in. (42 kgf/cm² or 4.1 MPa) with its talons. It can also lift more than three-quarters of its body weight.
When in pursuit of prey, harpy eagles can reach speeds of up to 50 miles per hour. This powerful hunter only eats freshly caught meat, and it brings its catch back to the nest to share with its mate and offspring. If the catch is too big to carry back to the nest, a harpy will eat what it can at the capture spot and bring home the more manageable leftovers. Harpy eagles are known to hunt creatures as large as themselves, and sometimes even larger.
They prefer to roost in prominent trees, especially silk-cotton trees, and they make their nests 90 -140 ft above the forest floor. Nests, which can measure up to five feet across, are built from sticks and lined with softer materials like green leaves and seedpods. Some offspring return as adults to the same trees in which they were reared to build their own nests.
Pairs are monogamous and lay two white eggs in a large stick nest high in a tree, raising one chick every 2–3 years. After the first chick hatches, the second egg is ignored and fails to hatch. The chick fledges in 6 months, but the parents continue to feed it for another 6 to 10 months. It can be aggressive toward humans who disturb its nesting sites or appear to be a threat to its young. The harpy often builds its nest in the crown of the kapok tree, one of the tallest trees in South America. In many South American cultures it is considered bad luck to cut down the kapok tree, which may help safe guard the habitat of this stately eagle.
Like all eagles, the harpy has evolved extraordinary eyesight. Eagle eyes are enormous, taking up a large portion of their skull. They are almost too large to move side-to-side with only their eye muscles, so instead the eagle rotates its head (up to 270°) as it scans the horizon for prey. This frequent head movement may seem like a burden, but its fixed eyes actually allow the eagle’s vision to be more precise. Because their eye muscles barely move, eagles can focus on small and far away objects.
For a larger bird, the wingspan of the harpy eagle is relatively small, an adaptation that increases maneuverability in forested habitats.
Harpy eagles are considered to be one of the world’s largest and most powerful eagles. Although this eagle has hind talons up to the size of grizzly bear claws, they typically can only fly with prey weighing up to approximately one half of their body weight.
Harpy eagles, like many other birds of prey, bring fresh green twigs and branches to the nest. Some researchers think this helps to fumigate the nest against insects and parasites, and provide a cooler environment for the nestling.
Its name references the harpies from Ancient Greek mythology. These were wind spirits that took the dead to Hades, and were said to have a body like an eagle and the face of a human.
The Harpy Eagle is the national bird of Panama and is depicted on the coat of arms of Panama.
The harpy eagle is sparsely distributed and generally rare throughout its extensive range in south Mexico, Guatemala, Belize (recently confirmed), Honduras, Nicaragua, Costa Rica, Panama (including four birds introduced in 1998), Colombia, Venezuela, Guyana, Suriname, French Guiana (perhaps 200-400 pairs), Ecuador, Peru, Bolivia, Brazil, Paraguay and north-east Argentina (Misiones, but formerly Formosa, Salta and Jujuy). It is thought to be locally or regionally extinct in large parts of its former range, notably most of central and north Central America and possibly Rio Grande do Sul, Brazil, but recent records suggest that the population in the southern Atlantic forests may be migratory.
Although still reasonably common in the Amazonian forests of Brazil and Peru, it will only survive in the long term if the escalating rate of forest destruction in the region is brought under control and a network of inviolate reserves established. Low overall population densities and slow reproductive rates make shooting the most significant threat over its entire range. It could perhaps survive in disturbed forests or even forest mosaics if its large size and boldness in the face of humans did not make it an irresistible target for hunters. It presumably also suffers from competition with humans for prey.
Conservation actions underway: CITES Appendix I and II. Reintroductions have taken place in Belize and Panama. Conservation actions proposed: Work with local communities to reduce hunting. Strengthen network of protected areas to include core remaining areas of habitat. Clarify its precise ecological requirements and its ability to persist in fragmented and altered habitats.
Jacksonville Zoo History:
Harpy eagles have been on the Jacksonville Zoo inventory since at least 1969, although during most of that time (1976-2004) the inventory listing was only represented by an eagle on loan to the Fort Worth Zoo.