Harpy Eagle

The Harpy Eagle (Harpia harpyja), is a Neotropical species of eagle. It is sometimes known as the American Harpy Eagle to distinguish it from the Papuan Eagle which is sometimes known as the New Guinea Harpy Eagle or Papuan Harpy Eagle. It is the largest and most powerful^[quantify] raptor found in the Americas, and among the largest extant species of eagles in the world. It usually inhabits tropical lowland rainforests in the upper (emergent) canopy layer. Destruction of its natural habitat has seen it vanish from many parts of its former range, and it is nearly extirpated in Central America.

Popular culture

• The Harpy Eagle is the national bird of Panama and is depicted on the coat of arms of Panama.
• The Harpy Eagle is featured on the cover of the O'Reilly Media book, R in a Nutshell.
• The Harpy Eagle was the inspiration behind the design of Fawkes the Phoenix in the Harry Potter film series.
• A Harpy Eagle called Bubba features extensively in Garry Kilworth's novel "Frost Dancers" as the adversary of the hares that are the heroes of the book.
• The 15th Harpy Eagle, named "Hope" released in Belize, was dubbed, "Ambassador for Climate Change," in Belize, in light of the United Nations Climate Change Conference 2009

• Description

  
  

  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. Theplumage of male and female is identical. The tarsus is up to 13 cm (5.1 in) long.^[4][5]

  
  

  

  Upper body of an adult in captivity

  Female Harpy Eagles typically weigh 6 to 9 kg (13 to 20 lb).^[4][6] One source states that adult females can scale up to 10 kg (22 lb).^[7] An exceptionally large captive female, "Jezebel", weighed 12.3 kg (27 lb).^[8] Being captive, this large female may not be representative of the weight possible in wild Harpy Eagles due to differences in the food availability.^[9][10] The male, in comparison, is much smaller and weighs only about 4 to 4.8 kg (8.8 to 11 lb).^[4][6] Harpy Eagles are 86.5–107 cm (2 ft 10 in–3 ft 6 in) long^[5][6] and have a wingspan of 176 to 224 cm (5 ft 9 in to 7 ft 4 in).^[4][5] 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).^[4][11][12] It is sometimes cited as the largest eagle, however the Philippine Eagle is somewhat longer on average and theSteller's Sea Eagle is slightly heavier on average. 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.^[4] The extinct Haast's Eagle was significantly larger than all extant eagles, including the Harpy.^[13]

  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 Wheeeeeeeeee-wheeeeeee-wheeeeeeeee. 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 nestling have been described as uttering croaks, quacks and whistles.^[14]

  Behavior

  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. 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).^[17] 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.^[4] At several nest inGuyana, monkeys made up approximately 37% of the prey remains found at the nests.^[18] Similarly, cebid monkeys made up 35% of the remains found at 10 nest in Amazonian Ecuador.^[19] 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.^[4] In the Pantanal, a pair of nesting eagles preyed largely on the porcupine Coendou prehensilisand on the agouti Dasyprocta azarae.^[20] 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%.^[21] Other parrots, including the large Hyacinth Macaw, have also been predated, as well as cracids such as curassows andseriemas.^[4] Additional prey items reported include reptiles such as iguanas, tejus and snakes.^[4][22] 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.^[4] 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.^[4][23][24] 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.^[25][26] The Harpy have been recorded as taking domestic livestock, including chickens, lambs, goats and young pigs, but this is extremely rare under normal circumstances.^[4] 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.^[27]

  
  

  T  he Harpy Eagle routinely favors prey weighing over 7 kg (15 lb).^[4] The harpy eagle possess the largest talons of any living eagle, each exceeding the length of grizzly bear's claw at around 13 cm (5.1 in).^[23] The Harpy's feet are extremely powerful and assist with suppressing prey. A typical Harpy Eagle can exert a pressure of 42 kgf/cm² (4.1 MPa or 530lbf/in² or 400 N/cm²) with its talons.^[28] The Harpy Eagle has been recorded as lifting prey up to equal their own body weight.^[4] That allows the bird to snatch a live sloth from tree branches, as well as other huge prey items. Males have been shown to focus on 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.^[4] The larger females almost invariably take larger prey, with a minimum recorded prey weight of around 2.7 kg (6.0 lb). Adult female Harpys regularly grab large male howleror 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.^[4][23][29] 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).^[4] 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).^[14]

  Sometimes, Harpy Eagles will still-hunt, a common hunting strategy in other forest-dwelling raptors.^[4] In Harpys, this consists of looking and listening for long periods of time from a high perch near an opening, a river or salt-lick (where many mammals go to feed for nutrients).^[4] 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.^[4] When prey is spotted, a fast swoop or snatch occurs, after which the talons often kill the prey in seconds.^[4] On occasion, Harpy Eagles may also hunt by flying adjacent to or right over the canopy.^[4] They have also been observed tail-chasing, a predation style common to the bird-hunting Accipiter hawks.^[4] While tail-chasing, they pursue a bird closely in flight while twisting between trees, vines and branches, a skill that requires both considerable speed and great agility

  Breeding

  
  

  In ideal habitats, nests can be found fairly close to one another. In some parts of Panama and Guyana, active nests were located 3 km (1.9 mi) away from one another, while were within 5 km (3.1 mi) of each other in Venezuela. In Peru, the average distance between nests was 7.4 km (4.6 mi) and the average area occupied by each breeding pairs was estimated at 4,300 ha (11,000 acres). In less ideal areas, with fragemented forest, breeding territories were estimated at 25 km (16 mi).^[22] The female Harpy Eagle lays two white eggs in a large stick nest, which commonly measures 1.2 m (3.9 ft) deep and 1.5 m (4.9 ft) across and may be used over several years. Nests are located high up in a tree, usually in the main fork, at 16 to 43 m (52 to 141 ft), depending on the stature of the local trees. 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 safeguard the habitat of this stately eagle.^[30] The bird also uses other huge trees to build its nest on, such as the Brazil nut tree.^[31] A nesting site found in the Brazilian Pantanal was built on a Cambará tree (Vochysia divergens).^[32]

  There is no known display between pairs of eagles and they are believed to mate for life. A pair of Harpy Eagles usually only raise one chick every 2–3 years. After the first chick hatches, the second egg is ignored and normally fails to hatch unless the first egg perishes. The egg is incubated for around 56 days. When the chick is 36 days old, it can stand and walk awkwardly. The chick fledges at the age of 6 months, but the parents continue to feed it for another 6 to 10 months. The male captures much of the food for the incubating female and later the eaglet, but will also take an incubating shift while the female forages and also brings prey back to the nest. Breeding maturity is not reached until birds are 4 to 6 years of age.^[4][14][16] Adults can be aggressive toward humans who disturb the nesting site or appear to be a threat to its young.

  In ideal habitats, nests can be found fairly close to one another. In some parts of Panama and Guyana, active nests were located 3 km (1.9 mi) away from one another, while were within 5 km (3.1 mi) of each other in Venezuela. In Peru, the average distance between nests was 7.4 km (4.6 mi) and the average area occupied by each breeding pairs was estimated at 4,300 ha (11,000 acres). In less ideal areas, with fragemented forest, breeding territories were estimated at 25 km (16 mi).^[22] The female Harpy Eagle lays two white eggs in a large stick nest, which commonly measures 1.2 m (3.9 ft) deep and 1.5 m (4.9 ft) across and may be used over several years. Nests are located high up in a tree, usually in the main fork, at 16 to 43 m (52 to 141 ft), depending on the stature of the local trees. 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 safeguard the habitat of this stately eagle.^[30] The bird also uses other huge trees to build its nest on, such as the Brazil nut tree.^[31] A nesting site found in the Brazilian Pantanal was built on a Cambará tree (Vochysia divergens).^[32]

  There is no known display between pairs of eagles and they are believed to mate for life. A pair of Harpy Eagles usually only raise one chick every 2–3 years. After the first chick hatches, the second egg is ignored and normally fails to hatch unless the first egg perishes. The egg is incubated for around 56 days. When the chick is 36 days old, it can stand and walk awkwardly. The chick fledges at the age of 6 months, but the parents continue to feed it for another 6 to 10 months. The male captures much of the food for the incubating female and later the eaglet, but will also take an incubating shift while the female forages and also brings prey back to the nest. Breeding maturity is not reached until birds are 4 to 6 years of age.^[4][14][16] Adults can be aggressive toward humans who disturb the nesting site or appear to be a threat to its young.^[