Wedge-tailed eagle (Aquila audax)

loading
Wedge-tailed eagle
IUCN Red List species status – Least Concern LEAST
CONCERN

Top facts

  • The wedge-tailed eagle is the largest bird of prey in Australia, and one of the largest birds of prey in the world.
  • The wedge-tailed eagle is named for its long, diamond-shaped tail.
  • Wedge-tailed eagles sometimes hunt cooperatively, and are able to take prey several times their own weight.
  • The wedge-tailed eagle builds a massive stick nest that can be over two metres across and up to four metres deep.
loading
Loading more images and videos...

Wedge-tailed eagle fact file

Wedge-tailed eagle description

KingdomAnimalia
PhylumChordata
ClassAves
OrderFalconiformes
FamilyAccipitridae
GenusAquila (1)

The largest bird of prey in Australia (4), the wedge-tailed eagle (Aquilaaudax) is a huge, powerful eagle with a distinctively long, diamond-shaped tail. Its long, relatively narrow wings have deeply notched tips, and its shoulders appear prominent when the eagle is at rest. The wedge-tailed eagle has a relatively small, flat head with a massive, formidable beak, and its legs are covered in baggy feathering all the way to the feet (2) (4) (5).

The adult wedge-tailed eagle is largely dark brownish-black, except for reddish-brown hackles on the back of its neck and a narrow, mottled grey-brown band across the upper wing. The undertail-coverts are paler brown, while pale bases to the flight feathers are visible on the underside of the wings (2) (4) (5). The wedge-tailed eagle’s eyes are brown and its cere and feet are creamy white (2) (4).

The male and female wedge-tailed eagle are similar in appearance, but the female is usually slightly larger and heavier than the male (2) (4) (5). Juvenile wedge-tailed eagles are easily distinguishable from the adults, being mainly dark brown with reddish edges to the feathers and a light golden to reddish-brown nape, back and upperwing band. The wing band is much wider than in the adult, taking up more than half of the width of the wing (2) (4).

The head and chest of the juvenile wedge-tailed eagle are paler and streakier than in the adult, and its underwings and tail are barred. Occasionally, all-black juveniles also occur. The juvenile’s eyes are grey to light brown, and its cere and feet are yellowish to cream. Juvenile wedge-tailed eagles gradually become darker and more adult-like in plumage as they age, but do not reach full adult plumage until their seventh or eighth year of life (2) (4).

Two subspecies of wedge-tailed eagle are recognised. The Tasmanian wedge-tailed eagle, Aquila audax fleayi, differs from its mainland counterpart, Aquilaaudax audax, mainly by its whitish-buff or cream rather than golden or reddish-brown nape (2) (5). Adults of the Tasmanian subspecies rarely attain the near all-black plumage that can sometimes be seen in older birds on the mainland (5).

The wedge-tailed eagle is not usually very vocal, but may sometimes give whistles, yelps and squeals, which often have a rolling quality (2) (4). This species also gives a thin, high whistle followed by a short, weak-sounding ‘see-tyu(2).

Also known as
Australian wedge-tailed eagle, eaglehawk, mountain eagle, Tasmanian wedge-tailed eagle.
Size
Length: 85 - 106 cm (2)
Wingspan: 182 - 232 cm (2)
Male weight: 2 - 4 kg (2)
Female weight: 3.1 - 5.3 kg (2)
Top

Wedge-tailed eagle biology

The wedge-tailed eagle can often be seen perching conspicuously on a dead tree, telegraph pole or rocky prominence, or soaring majestically on slightly upswept wings. Territorial individuals often soar high for long periods in display, and may swoop at intruders, even being aggressive towards hang-gliders and aircraft (2) (4).

This powerful bird of prey hunts a variety of terrestrial mammals, as well as some reptiles and birds. Where they are common, rabbits make up most of the wedge-tailed eagle’s diet, but it will also take wallabies, kangaroos, hares, possums, cats, dogs, foxes and young goats and lambs (2) (4) (5). This species’ reptile prey includes large lizards and occasionally snakes, and it may take birds such as crows, parrots, ducks and even herons, cranes and bustards (2) (4).

Carrion is also an important food source for the wedge-tailed eagle, particularly during winter or for younger birds which lack hunting experience (2) (5). Groups of up to a dozen or more wedge-tailed eagles have been known to gather at large carcasses, and this species may also steal food from other birds of prey (2) (4).

The wedge-tailed eagle typically seizes its prey from the ground, but it will also take it from the forest canopy, and sometimes even removes animals such as possums from tree hollows or takes young birds out of nests (2) (4). This powerful eagle is capable of taking prey several times its own weight, although most of its prey is much smaller than this. The wedge-tailed eagle sometimes hunts cooperatively in pairs or even in small groups (2) (4) (5).

Although immature wedge-tailed eagles are often gregarious, the adults are usually found alone or in pairs (2) (5), and are believed to mate for life (5). Breeding pairs of wedge-tailed eagles defend a territory (5), and often perform soaring displays that may culminate in rolling, touching talons, or steep dives followed by upwards swoops (2) (4). This species usually breeds between April and December, depending on the location (2). Populations in northern Australia have been recorded breeding in January and February (2), while those in Tasmania breed between August and September (5).

The wedge-tailed eagle builds a large stick nest, which after repeated use over many years may reach up to 2.5 metres across and nearly 4 metres in depth (2). The nest is typically built in a large tree, or sometimes on rocks, cliff edges, or even on the ground where trees are sparse. The adults often line the nest with green leaves and twigs (2) (4) (5). The pair’s territory may contain a number of nests, but usually one is favoured and is re-used each year. Wedge-tailed eagles often nest in traditional sites, with the same site being used for up to 50 years (5).

The female wedge-tailed eagle normally lays one to two eggs (2) (4), with one being more usual in the Tasmanian subspecies (5). The eggs are incubated by both adults for 42 to 48 days, and the young eagles fledge at about 70 to 95 days old (2). After leaving the nest, the juvenile wedge-tailed eagles remain dependent on the adults for a further three to six months (2) (4), after which the young birds disperse (4). The wedge-tailed eagle reaches sexual maturity at about three to five years old, but does not usually begin to breed for another year or two. This long-lived species may potentially reach 20 to 25 years old in the wild, and up to 40 years old in captivity (2) (5).

Top

Wedge-tailed eagle range

The wedge-tailed eagle is widespread across Australia, including Tasmania, and also occurs in parts of southern New Guinea (2) (4). In addition, it is found on a number of offshore islands, such as Flinders Island, Maria Island and Kangaroo Island (2) (5).

The subspecies A. a. audax occurs on mainland Australia and New Guinea, while A. a. fleayi occurs only in Tasmania and on nearby islands (2) (5).

Top

Wedge-tailed eagle habitat

This large eagle is found in a wide variety of habitats, from forest and woodland to savanna and treeless plains (2) (5). However, the wedge-tailed eagle is rarely found in intensively cultivated areas and is usually absent around human settlements (2) (4).

The wedge-tailed eagle often hunts in quite open country, but typically nests in dense forest (2) (5).

Top

Wedge-tailed eagle status

The wedge-tailed eagle is classified as Least Concern (LC) on the IUCN Red List (1) and is listed on Appendix II of CITES (3).

IUCN Red List species status – Least Concern

Top

Wedge-tailed eagle threats

The wedge-tailed eagle is abundant and widespread, and its overall population is believed to be increasing as a result of forest clearance, the introduction of rabbits to Australia, and abundant carrion due to roadkill (2) (4) (6). However, this species has been widely persecuted because of a mistaken belief that it has an impact on domestic livestock, and despite legal protection it is still illegally shot, trapped and poisoned in some areas (2) (4).

This large eagle is a shy nester, and human activity often leads it to abandon its nest. As a result, it may have been affected by disturbance in heavily settled and intensively farmed parts of its range (4), although it appears to be habituating to human activity in some areas (7). Deaths due to collisions with wind turbines have also been cited as a potential threat to the wedge-tailed eagle, but the impacts of this are not yet clear (4).

The Tasmanian subspecies of the wedge-tailed eagle, A. a. fleayi, has a restricted range and more specific habitat requirements than the mainland subspecies, A. a. audax (2) (4), needing undisturbed old-growth forest in which to nest (5). With an estimated population of under 1,000 individuals, of which only around 440 are mature adults, this subspecies is considered to be at risk of extinction. The main threats to the wedge-tailed eagle in Tasmania are forest clearance, illegal persecution, secondary poisoning from bait intended for other species, illegal hunting for mounted specimens, and collisions with fences, overhead wires and wind turbines (5) (8). This species is also very susceptible to disturbance at its nests, due to forestry operations, roads and recreation (5) (8) (9).

Top

Wedge-tailed eagle conservation

The Tasmanian subspecies of the wedge-tailed eagle is listed as Endangered under the Environment Protection and Biodiversity Act 1999 (5), as well as under the Tasmanian Threatened Species Protection Act 1995 (10). The mainland subspecies is also legally protected, for example by the National Parks and Wildlife Act 1974 in New South Wales, which makes it illegal to kill, trap, poison or capture this species (11). The wedge-tailed eagle is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species should be carefully controlled (3).

Conservation efforts for the wedge-tailed eagle have focused on the endangered Tasmanian subspecies, and a recovery plan has been published that aims to improve its conservation status, reduce mortality and increase its breeding success (8). Surveys have been conducted and a number of measures have been recommended for the protection and conservation of the wedge-tailed eagle’s nest sites. Public education materials have also been produced, to help reduce persecution (5) (8).

A large proportion of Tasmanian wedge-tailed eagle nests occur on private land or State Forests, and the recovery plan recommends that these be located and protected, as they are particularly vulnerable to human disturbance. The subspecies’ breeding success should also be monitored, and its conservation should be promoted among land owners and land managers (5) (8). Important requirements for the protection of wedge-tailed eagle nests include having an undisturbed ‘buffer zone’ around the nest site and reducing disturbance in the area during the breeding season (4) (9). The protection of wedge-tailed eagle nests will also benefit other species that rely on old-growth forest habitats (8).

Top

Find out more

Find out more about the wedge-tailed eagle and its conservation:

More information on conservation in Australia:

Top

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Top

Glossary

Carrion
The flesh of a dead animal.
Cere
In birds, an area of skin at the base of the upper mandible of the beak, surrounding the nostrils.
Coverts
Small feathers concealing the bases of larger flight feathers, usually on the wings or tail.
Flight feathers
The feathers at the end of the wing, involved in flight.
Incubate
To keep eggs warm so that development is possible.
Nape
The back of the neck.
Subspecies
A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
Territorial
Describes an animal, a pair of animals or a colony that occupies and defends an area.
Territory
An area occupied and defended by an animal, a pair of animals or a colony.
Top

References

  1. IUCN Red List (October, 2012)
    http://www.iucnredlist.org/
  2. Ferguson-Lees, J. and Christie, D.A. (2001) Raptors of the World. Helm Identification Guides, A&C Black Publishers, London.
  3. CITES (October, 2012)
    http://www.cites.org/
  4. Debus, S. (2012) Birds of Prey of Australia: A Field Guide. Second Edition. CSIRO Publishing, Collingwood, Australia.
  5. Department of Sustainability, Environment, Water, Population and Communities (2012) Aquilaaudax fleayi. In: Species Profile and Threats Database. Department of Sustainability, Environment, Water, Population and Communities, Canberra. Available at:
    http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=64435
  6. BirdLife International - Wedge-tailed eagle (October, 2012)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=3538
  7. Debus, S.J.S., Hatfield, T.S., Ley, A.J. and Rose, A.B. (2007) Breeding biology and diet of the wedge-tailed eagle Aquila audax in the New England region of New South Wales. Australian Field Ornithology, 24: 93-120.
  8. Bell, P.J. and Mooney, N.J. (1998) Wedge-tailed Eagle Recovery Plan 1998-2003. Department of Primary Industries, Water and Environment, Hobart. Available at:
    http://www.environment.gov.au/biodiversity/threatened/publications/recovery/wedge-tail/index.html
  9. Mooney, N. and Holdsworth, M. (1991) The effects of disturbance on nesting wedge-tailed eagles (Aquila audax fleayi) in Tasmania. Tasforests, 3: 15-31.
  10. Tasmania - Threatened Species Protection Act 1995 (October, 2012)
    http://www.dpiw.tas.gov.au/inter.nsf/webpages/sjon-58k8wk?open
  11. New South Wales Government: NSW legislation - National Parks and Wildlife Act 1974 (October, 2012)
    http://www.legislation.nsw.gov.au/maintop/view/inforce/act+80+1974+cd+0+N
X
Close

Image credit

Wedge-tailed eagle  
Wedge-tailed eagle

© Martin B Withers / www.flpa-images.co.uk

FLPA - images of nature
Pages Green House
Wetheringsett
Stowmarket
Suffolk IP14 5QA
United Kingdom
Tel: +44 (0) 1728 861 113
Fax: +44 (0) 1728 860 222
pictures@flpa-images.co.uk
http://www.flpa-images.co.uk

X
Close

Link to this photo

ARKive species - Wedge-tailed eagle (Aquila audax) Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

Conservation in Action

Which species are on the road to recovery? Find out now »

This species is featured in:

This species is found in Barrow Island. Visit our Barrow Island topic page to find out more.

Help us share the wonders of the natural world. Donate today!

Blog