Papuan Harpy Eagle

*For the American harpy eagle, click here*

## About

A Papuan harpy eagle in captivity.

The Papuan harpy eagle ***(Harpyopsis novaeguinea)*** is a large eagle native to the Island of New Guinea. They can be separated by the closely related American harpy eagle ***(Harpia harpjya)*** by their morphology and geographic range. Papuan harpy eagles have mostly tan plumage, which is noticeably light on their chest, breast and underbelly as well as on their underwings. The primary and secondary feathers of the underwings are striped with progressively thicker brown bars as they reach the tip. The back, tail feathers and head are a dusty grey-brown colour and the beak is a grey-black. The legs and feet are similar to the harpy eagle's in that they are a contrasting yellow. The eyes are commonly represented as a deep amber, though they darken with age to an almost red colour. The Papuan harpy eagle is also equipped with capable talons. Papuan harpy eagles are large eagles and overall very large in comparison to other raptors. Adult eagles grow to 75-90cm (30-35in) in length, can weigh up to 1.6-2.4kg (3.5-5.3lbs and have a wide yet broad wingspan of 1.21-1.57m (4-5.2ft). Females are 34% larger than males on average.

## Diet

The Papuan harpy eagle is a powerful predator that preys mostly upon arboreal marsupials, mostly belonging to the family phalangeridae. The colloquial term for arboreal marsupials (mostly possums) in New Guinea is '*kapul*' and so the species is sometimes referred to as the kapul eagle or the kapul-eating eagle. Specifically, the Papuan harpy eagle preys on rodents, spotted cuscus ***(Spilocuscus maculatus)***, dorcopsises ***(Dorcopsis)***, dorcopsuluses ***(Dorcopsulus)***, various bird species including cockatoos and and hornbills, reptiles, insects and even monitor lizards. Incidents of predation on Matschie's tree kangaroo ***(Dendrolagus matchiei)***, and even juvenile cassowaries have been recorded. Papuan harpy eagles ambush their prey from above before they clean their prey of their innards and fur before carrying the corpse to a perch to eat. In some birds of prey, weight gain has been observed to detriment flight as a result of the consumption of large prey however, due to the Papuan harpy eagle's short flight patterns, this may not be an issue for the species. It is likely the apex predator of the entire Island.

## Conservation Status

Papuan harpy eagles are classed as vulnerable by the IUCN and is mostly threatened by hunting across its range. The species is most prolifically hunted for the use of its feathers as traditional accessories like headdresses by the indigenous peoples of Papua New Guinea. Papuan harpy eagles seem to be hunted less in higher altitude environments where it is harder for hunters to locate them. They have persisted in areas of their distribution despite hunting pressures, particularly in the heavily hunted Ok Tedi area, where hunting seems to have lessened, with only three casualties occurring over the past four years (as of mid 2022). Infrastructural developments and general logging for the practice of palm oil farming and mining have also destroyed valuable habitat and in turn brought the species into closer contact with humans, increasing hunting. There are no current actions being taken to limit threats to the species.

## Range and Population

The Papuan harpy eagle is endemic to the Island of New Guinea and lives predominantly in montane/cloud rainforests and tropical grasslands at elevations of at least 3,200m (10,498ft). Papuan harpy eagles are widely distributed throughout the Island however, they are uncommon and low in population density. It is thought that the population density of the species has always been low though, due to likely restricted breeding periods however, the Papuan harpy eagle population has never faced such an adverse decline as it is currently. There are likely just 3,200-4,000 mature individuals remaining in the wild due to hunting pressures discussed previously however, as much as 15,000 Mature eagles may exist in remote areas of their distribution. It is likely that 1,600-2,000 breeding pairs exist within the initial estimate.

## Behaviour

Due to the enigmatic nature of the Papuan harpy eagle, little is known about its behavioural characteristics and the breeding habits of the species are even more obscure. According to the University of Papua New Guinea, the Papuan harpy eagle exhibits to main calls, the first being a low twangy hooting "*uuhm*" associated with matured eagles and the second being a repeated hiccup-like "*ukh-ukh*" or "*bungh-bungh*" croak most commonly associated with juveniles. The latter can sometimes sound like a creak or poignant groan, sounding similar to an "*urkh*" or "*erhm*". When producing this call, the juvenile will tilt its head, aligning it with its tail before sounding off in a harsh gulping motion, producing the low call. When repeating this call, the juvenile may turn its head in an alternating cycle per note it produces, calling in one direction then the next. Duets between breeding pairs seem to be a combination of the two calls. It is believed that Papuan harpy eagles mate during the dry season from April-November. This theory is supported by the discovery of a breeding-ready individual during June, who built a nest in April-May and had reared large nestlings by August. Large emergents seem to be the Papuan harpy eagle's preferred nesting sites , typically ranging 30m (98ft) off ground-level. Desirable trees are an average of 8.7m (29ft) taller than the surrounding canopy, occur on a slope and have less low-hanging limbs than others. Nests are constructed from branches and other woody materials, the interiors of nests are finished with grasses, sprigs, feathers and furs. and are typically placed atop mosses and epiphytes. The nests are massive, ranging 3m (9.8ft) in both height and diameter. One egg is likely laid, with evidence of larger clutches being undocumented. Egg-laying and feeding behaviours as well as the fledging process are all currently undocumented. It has been suggested that breeding is postponed until the current offspring has reached maturity, resulting in more infrequent breeding season ranging from 2-3 year differences. Young birds have been seen in proximity to their parents, in similarity to the American harpy eagle, suggesting possible monogamous behaviour among adults. Breeding pairs will also reuse nests per breeding season, further supporting this theory. Among fledged juveniles, short flights between common roosting trees was recorded, with one study published in 2005 conducted by Leo. A. Toweyasali Legra finding that very few flights were made by birds exceeding a distance of 100m (329ft). It is hypothesised that these shorter flight patterns may suggest hunting behaviour, as during flights eagles survey the surrounding land thoroughly. They likely only fly long distances when clearing large areas of land or pursuing avian prey, even opting sometimes to just climb trees and search cavities for prey rather than flying.

### Relationship with Humans

The Papuan harpy eagle is hunted for the use of its feathers in traditional headdresses and other accessories. They are hunted incredibly frequently throughout almost every forest they occur in. Papuan harpy eagles also face competition for food with humans, who often hunt the same or similar species to the eagles. The eagle itself may also be hunted as bushmeat by indigenous people.

## In Captivity

Papuan harpy eagles can be found in some aviaries in Papua New Guinea, but are not established to be housed in any major zoos, limiting available captive conservation breeding programs.

## Sources

* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/22696007/217864181
* Papuan Eagle | Wikipedia - https://en.wikipedia.org/wiki/Papuan\_eagle
* Nest-site selection and Behavioural Biology of the New Guinea Harpy Eagle | The University of Papua New Guinea School of Natural and Physical Sciences Department of Biology, Harpyopsis novaeguinea - https://assets.peregrinefund.org/docs/pdf/research-library/2005/2005-Legra-New-Guinea-Harpy-Eagle.pdf
* Papuan Eagle | Encyclopedia of Life - https://eol.org/pages/914592/articles
* New Guinea Eagle, Audio | eBird - https://media.ebird.org/catalog?taxonCode=negeag1&mediaType=audio
* Papuan Eagle | Palm Oil Detectives - https://palmoildetectives.com/2022/09/28/papuan-eagle-harpyopsis-novaeguineae-2/