Harpy Eagle

*For the Papuan harpy eagle, click here*

## About

A harpy eagle perched on a tree branch.

The harpy eagle ***(Harpia harpyja)*** is a large eagle species which occurs throughout the rainforests of South and Central America. It is sometimes called the American harpy eagle to differentiate it from the Papuan harpy eagle ***(Harpyopsis novaeguinea)***. Harpy eagles are monotone in plumage, possessing a mostly dark grey body, a white underbelly, chest and underwing with black longitudinal markings, a grey head and a grey tail with black barred tail feathers and a white underside. The head is very particular in that the feathers create a disk-like shape around the harpy eagle's face and also stick out from the back of the bird's head, similarly to what has been described as a "crown". Harpy eagles have short hooked beaks, large dark eyes and yellow feet equipped with oversized talons which all aid in hunting prey. Harpy eagles are the largest eagle species in the world, reaching 89-102cm (35-40in) in length and possessing a wingspan of up to 2m (6.6ft). Males weigh 5-8kg (11-17lbs), while females are heavier on average, weighing up to 7-9kg (15-19lbs).

## Diet

Harpy eagles are excellent predators and hunt a variety of different species. They most frequently prey on primates in particular however, are known to also target birds -such as macaws and seriemas-, small terrestrial and arboreal mammals, lizards, rodents -such as the prehensile-tailed porcupine ***(Coendou prehensilis)*** and the Azara's agouti ***(Dasyprocta azarae)***- and even small deer and juvenile peccaries. Harpy eagles are apex predators and as such are known to hunt smaller secondary predators including the tayra ***(Eira barbara)***, the greater grison ***(Galictis vittata)*** and the margay ***(Leopardus weidii)***. The most common prey item taken by the harpy eagle is sloths and small to large monkeys, making up 79% and 37% of the species total diet respectively. The harpy eagle uses its 12.5cm (5in) talons (the largest talons of any eagle) to subdue prey, capturing prey and flying it to a tree to perch and eat. They use their sense of sight to initially locate prey through the canopy, a process which may take an eagle 23 hours to complete. This method is known as "sitting and waiting" and is common among forest-dwelling raptors. When sitting and waiting, a harpy eagle will perch near a water body or salt lick, as they are common places for prey items to gather. They are particularly adept flyers, swiftly moving thorough the underbrush and thick arboreal foliage to pursue prey in a hunting method known as "tail-chasing" most commonly exhibited in much smaller hawk species. Harpy eagles frequently lift prey which weighs just as much as themselves, though females are known to take larger prey than males.

## Conservation Status

Harpy eagles are classed as vulnerable via the IUCN and are primarily threatened by deforestation and land clearing which destroy the species' habitat. Illegal mining is a particularly threatening practice which disturbs valuable habitat and causes other adverse effects such as water contamination and pollution. Agricultural practices such as mismanaged land clearing causes detrimental habitat fragmentation and also allows the harpy eagle to come in closer contact with humans, leading to human-wildlife conflict. The construction of hydroelectric damns, development of infrastructure like roads and uncontrolled fires all also fragment available eagle habitat. Due to climate change and related factors, the harpy eagle's distribution is predicted to diminish by 7-14% by 2090. Selective logging also targets most of the harpy eagle's known nesting tree species, further threatening the eagle. Deforestation is particularly common in the southeast Amazon and the Brazilian Atlantic forest, where the harpy eagle species is put at risk of regional/local extinction. Deforestation and selective logging also destroy understory and canopy coverage, disturbing prey and leading to food availability issues for the species. Additionally, harpy eagles have faced near regional extinction in the Yucatan peninsula as a direct result of massive deforesting and though there has been reintroduction efforts in Belize and Panama, individuals did not survive long enough to establish a breeding population. The Peregrine Fund, -a conservation organisation that specialises in the preservation of raptor species- is responsible for these reintroductions and worked with multiple Latin American governments and national zoos and conservatories to breed and release the eagles. During this campaign (which began in 1989) the Peregrine Fund raised awareness for the species across its range and ensured that the harpy eagles could safely reintegrate. Despite rigorous efforts however, the 50 individuals reintroduced to Belize and Panama could not establish a breeding population. Through this experience the Peregrine Fund aims to better their knowledge of eagle breeding and continues to observe wild Panamanian populations closely.

## Range and Population

Thee harpy eagle is found throughout South and Central America, occurring as far north as southern Mexico and as far south as southeast Paraguay and northeast Argentina. The species inhabits dense lowland rainforests and occasionally tropical savannas in less ideal environments. The harpy eagle typically exists at around 900m (2,952ft) from sea level, -though they have been recorded at up to 2,000m (6,561ft)-, preferring canopies and emergents over understories as it allows them to better identify prey. It has been found that although harpy eagles usually depend on tree cover for food abundance, some populations can exist in disturbed areas with more encroachment-tolerant prey. The overall harpy eagle population has been estimated at 100,000-250,000 mature individuals and the species is still facing declines.

## Behaviour

Harpy eagles communicate through a variety of different means, most frequently through long "uuuuaaahaaau" calls which are used to establish and maintain territory, but also in miscellaneous whistles, croaks, clicks and mews. The protruding feathers which adhorn the harpy eagle's head with rise when startled or threatened and it is hypothesised that they also rise in correlation to thee volume of the environment around them. Monogamous breeding pairs are known to communicate in a tactile manner, clacking their bills together as a form of mutual bonding, they will also chirp and coo to each other during their shared nest-making process. In idyllic habitats, nests are never far from one another, ranging from 3-7.4km (1.8-4.6mi) apart in correlation to specific eagle populations. The territory of a single breeding pair can reach 4,300ha (11,000ac) in size. In disturbed ranges, these territories are much smaller as a result of habitat and population fragmentation, being an average of just 25km (16mi). Paired eagles will construct a large nest of twigs, sticks and branches in the fork of a high tree, typically a kapok ***(Ceiba pentandra)*** or Brazil nut tree ***(Bertholletia excelsa)***. The nest is typically 1.2m (3.9ft) deep and 1.5m (4.9ft) across. Harpy eagles have no mating ritual or display and will mate multiple times over a multiple-day period. Pairs rarely venture more than 180m (590ft) from their nest once it has been constructed. The female will lay up to two white eggs in this nest, raising 2-3 chicks yearly proceeding the first egg hatching. The second egg is usually neglected, falling from the nest or hatching only if the first egg perishes. The egg is incubated for 56 days and at 36 days of age, the chick begins to waddle. The chick will fledge at 6-7 months, becoming an eaglet and still being fed by the parents for 6-10 months. The parents alternate between incubating the egg/chick and feeding their partner and the eaglet. Sexual maturity is not reached until 4-6 years and the juvenile eagle will likely orbit their parents until completely independent, which may take up to one year. The nest used to raise this chick will then be reused for years to come.

### Relationship with Humans

The harpy eagle is becoming increasingly common in proximity to farmlands and settlements as a direct result of habitat fragmentation and so is often killed in defense of livestock. Harpy eagles are known to prey on chickens, lambs, goats and juvenile pigs, though they do this rarely, likely as a result of desperation in times of food scarcity. Harpy eagles are also infrequently sold at illegal live animal markets. Across their Amazonian range, the harpy eagle is hunted for food and ornamental purposes, where eagle feathers are used in traditional headdresses, arrow fledges and as a general souvenir item. During the 1980s-90s at least 45 harpy eagles were killed in Venezuela alone. The harpy eagle has been seen in a more favourable light in some circumstances, particularly when the species was denoted as the national animal of Panama, appearing on the country's coat of arms, or when the bird was featured on the 2,000 bolívar banknote in Venezuela. The 15th harpy eagle to be reintroduced to Belize, was named hope and was seen as a symbol of actions taken against climate change in honour of the 2009 UN Climate Change Conference. Another harpy eagle, Luigi, was significant to the awareness programs conducted by the Peregrine Fund as a symbol of the docile nature of the harpy eagle towards humans.

## In Captivity

The harpy eagle is notoriously hard to breed in captivity, only being successfully bred by the San Diego Zoo, Zoo Miami and the Peregrine Fund headquarters, where conditions have been made perfect for breeding. The San Diego Zoo has successfully bred 15 harpy eagles since 1998, with two of them being reintroduced to Panama in coordination with the peregrine Fund. The zoo continues to work with the fund to raise awareness of the harpy eagle and its threats. Zoo Miami has reared one chick born from a breeding pair from San Diego, becoming the second zoo in the United States to do so. Captive breeding may prove incredibly important for the harpy eagle moving forwards, as habitats shrink and eagles decrease in wild numbers.

## Sources

* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/22695998/197957213
* Harpy Eagle | Wikipedia - https://en.wikipedia.org/wiki/Harpy\_eagle
* Harpy Eagle | Animal Diversity Web, University of Michigan Museum of Zoology - https://animaldiversity.org/accounts/Harpia\_harpyja/
* Harpy Eagle | Peregrine Fund - https://peregrinefund.org/explore-raptors-species/eagles/harpy-eagle
* Harpy Eagle | San Diego Zoo - https://animals.sandiegozoo.org/animals/harpy-eagle
* Harpy Eagle | Mongabay - https://rainforests.mongabay.com/kids/animal-profiles/harpy-eagle.html