Post by Runic on May 26, 2013 3:09:20 GMT 5
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Falconiformes (or Accipitriformes, q.v.)
Family: Accipitridae
Genus: Harpia
Species: H.harpyja
The upper side of the Harpy Eagle is covered with slate black feathers, and the underside is mostly white, except for the feathered tarsi, which are striped black. There is a broad black band across the upper breast, separating the gray head from the white belly. The head is pale grey, and is crowned with a double crest. The upperside of the tail is black with three gray bands, while the underside of it is black with three white bands. The iris is gray or brown or red, the cere and bill are black or blackish and the tarsi and toes are yellow. The plumage of male and female is identical. The tarsus is up to 13 cm (5.1 in) long.[7][8]
Female Harpy Eagles typically weigh 6 to 9 kg (13 to 20 lb).[7][9] One source states that adult females can scale up to 10 kg (22 lb).[10] An exceptionally large captive female, "Jezebel", weighed 12.3 kg (27 lb).[11] Being captive, this large female may not be representative of the weight possible in wild Harpy Eagles due to differences in the food availability.[12][13] The male, in comparison, is much smaller and weighs only about 4 to 4.8 kg (8.8 to 11 lb).[7][9] Harpy Eagles are 86.5–107 cm (2 ft 10 in–3 ft 6 in) long[8][9] and have a wingspan of 176 to 224 cm (5 ft 9 in to 7 ft 4 in).[7][8] Among the standard measurements, the wing chord measures 54–63 cm (1 ft 9 in–2 ft 1 in), the tail measures 37–42 cm (1 ft 3 in–1 ft 5 in), the tarsus is 11.4–13 cm (4.5–5.1 in) long and the exposed culmen from the cere is 4.2 to 6.5 cm (1.7 to 2.6 in).[7][14][15]
It is sometimes cited as the largest eagle alongside the Philippine Eagle, that is somewhat longer on average and the Steller's Sea Eagle, that is slightly heavier on average.[6] The wingspan of the Harpy Eagle is relatively small, an adaptation that increases maneuverability in forested habitats and is shared by other raptors in similar habitats. The wingspan of the Harpy Eagle is surpassed by several large eagles who live in more open habitats, such as those in the Haliaeetus and Aquila genera.[7] The extinct Haast's Eagle was significantly larger than all extant eagles, including the Harpy.[16]
This species is largely silent away from the nest. There, the adults give a penetrating, weak, melancholy scream, with the incubating male's call described as "whispy screaming or wailing".[17] The females calls while incubating are similar but are lower pitched. While approaching the nest with food, the male calls out "rapid chirps, goose-like calls, and occasional sharp screams". Vocalization in both parents decreases as the nestlings age, while the nestlings become more vocal. The nestlings call Chi-chi-chi...chi-chi-chi-chi, seemingly in alarm in respond to rain or direct sunlight. When humans approach the nest, the nestlings have been described as uttering croaks, quacks and whistles.[18]
The Harpy Eagle is an actively hunting carnivore and is an apex predator, meaning that adults are at the top of a food chain and have no natural predators.[21] Its main prey are tree-dwelling mammals and a majority of the diet has been shown to focus on sloths and monkeys. Research conducted by Aguiar-Silva between 2003 and 2005 in a nesting site in Parintins, Amazonas, Brazil, collected remains from prey offered to the nestling and after sorting them, concluded that, in terms of individuals preyed upon, the harpy's prey basis was composed in 79% by sloths from two species: Bradypus variegatus amounting to 39% of the individual prey base, and Choloepus didactylus to 40%; various monkeys amounted to 11.6% of the same prey base. In a similar research venture in Panama, where a couple of captive-bred subadults was released, 52% of the male's captures and 54% of the female's were of two sloth species (Bradypus variegatus and Choloepus hoffmanni).[22] At one Venezuelan nest, all remains found around the nest site were comprised by sloths. Monkeys regularly taken can include capuchin monkeys, saki monkeys, howler monkeys, titi monkeys, squirrel monkeys and spider monkeys. Smaller monkeys, such as tamarins and marmosets, are seemingly ignored as prey by this species.[7] At several nest in Guyana, monkeys made up approximately 37% of the prey remains found at the nests.[23] Similarly, cebid monkeys made up 35% of the remains found at 10 nest in Amazonian Ecuador.[24] Other partially arboreal mammals are also predated given the opportunity, including porcupines, squirrels, opossums, anteaters, and even relatively large carnivores such as kinkajous, coatis and tayras.[7] In the Pantanal, a pair of nesting eagles preyed largely on the porcupine Coendou prehensilis and on the agouti Dasyprocta azarae.[25] The eagle may also attack bird species such as macaws: At the Parintins research site, the Red-and-green Macaw made up for 0.4% of the prey base, with other birds amounting to 4.6%.[26] Other parrots, including the large Hyacinth Macaw, have also been predated, as well as cracids such as curassows and seriemas.[7] Additional prey items reported include reptiles such as iguanas, tejus and snakes.[7][27] Snakes of up to 5 cm (2.0 in) in diameter have been observed to be cut in half, then the pieces are swallowed whole.[7] On occasion, larger prey such as capybaras, peccaries and deer are taken and they are usually taken to a stump or low branch and partially eaten, since they are too heavy to be carried whole to the nest.[7][28][29] Red brocket deer, a species commonly weighing over 30 kg (66 lb), have been reportedly predated and, in such cases, the eagle may have to tear it into pieces or feed on at the killing site rather than fly with as it would be too heavy.[30] The Harpy have been recorded as taking domestic livestock, including chickens, lambs, goats and young pigs, but this is extremely rare under normal circumstances.[7] They control population of mesopredators such as capuchin monkeys which prey extensively on bird's eggs and which (if not naturally controlled) may cause local extinctions of sensitive species.[31]
The Harpy Eagle routinely takes prey weighing more than 7 kg (15 lb).[7] The harpy eagle possess the largest talons of any living eagle. The Harpy's feet are extremely powerful and can exert a pressure of 42 kgf/cm² (4.1 MPa or 530 lbf/in2 or 400 N/cm2) with its talons.[32] The Harpy Eagle has been recorded as lifting prey up to equal their own body weight.[7] That allows the bird to snatch a live sloth from tree branches, as well as other huge prey items. Males usually take relatively smaller prey, with a typical range of 0.5 to 2.5 kg (1.1 to 5.5 lb) or about half their own weight.[7] The larger females take larger prey, with a minimum recorded prey weight of around 2.7 kg (6.0 lb). Adult female Harpys regularly grab large male howler or spider monkeys or mature sloths weighing 6 to 9 kg (13 to 20 lb) in flight and fly off without landing, an enormous feat of strength.[7][28][33] Prey items taken to the nest by the parents are normally medium-sized, having been recorded from 1 to 4 kg (2.2 to 8.8 lb).[7] The prey brought to the nest by males averaged 1.5 kg (3.3 lb), while the prey brought to the nest by females averaged 3.2 kg (7.1 lb).[18]
Sometimes, Harpy Eagles are "sit-and-wait" predators (common in forest-dwelling raptors).[7] In Harpies, this consists of perching and watching for long time intervals from a high perch near an opening, a river or salt-lick (where many mammals go to feed for nutrients).[7] The more common hunting technique of the species is perch-hunting, which consists of scanning around for prey activity while briefly perched between short flights from tree to tree.[7] When prey is spotted, the eagle quickly dives and grabs the prey.[7] On occasion, Harpy Eagles may also hunt by flying within or above the canopy.[7] They have also been observed tail-chasing, a predation style common to hawks that hunt birds, the Accipiters.[7] This comprises the eagle pursuing another bird in flight, rapidly dodging among trees and branches, which requires both speed and agility.[7]
It's Name: The scientific and common names come from the Greek word, harpe, referring to a bird of prey mentioned by Aristotle, Pliny, and other Greek scholars, and may be from the mythological harpies who were winged creatures with sharp claws, a womanÂ’s face, and a vultureÂ’s body.
Interesting Facts: 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.
Strength & Hunting Technique
" Although other eagles are almost as heavy and some have larger wingspans, the harpy eagle of South America is without doubt the world's most powerful eagle. A female harpy eagle may weigh nearly 20 pounds (9 kg). Her legs may be as big around as a child's wrist; her feet tipped with 1.5-inch-long (3.75-cm-long) talons may span 9 inches (22.5 cm). With those legs and talons, the harpy is able to snatch large arboreal prey, including sloths and howler monkeys, from the branches where they live. It required slow motion footage shot in Guyana to reveal the technique employed by the harpy to take a sloth hanging from a branch. Deftly rolling in flight to pass under the branch, the eagle grabbed the sloth, wrenched it loose, and carried it off with hardly a break in its flight.A harpy eagle swooping down at 20 miles per hour (32 kph) generates approximately 13,500 foot-pounds (18,300 Newton-meters) of energy-- that's more than twice the muzzle energy of a bullet shot from a heavy rifle. Recent research has indicated that even the harpy eagle cannot carry the biggest animals it kills back to its nest. Adult harpy eagles probably feed on a carcass for a day or two before they eventually carry the more manageable maggoty remains to their chicks."
