Wedge-Tailed Eagle

## Description

The wedge-tailed eagle (Aquila audax ) is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. This very large but fairly lanky eagle has long, fairly broad wings, fully feathered legs, and an unmistakable wedge-shaped tail, with very elongated, strong beak and quite powerful feet. The wedge-tailed eagle is one of 12 species of large, predominantly dark-coloured booted eagles in the genus Aquila found worldwide. Genetic research has clearly indicated that the wedge-tailed eagle is fairly closely-related to other, generally quite large members of the Aquila genus. A large brown-to-black bird of prey, it has a maximum reported wingspan of 2.84 m (9 ft 4 in) and a length of up to 1.06 m (3 ft 6 in).

The wedge-tailed eagle is one of its native continent's most generalized birds of prey. They reside in most habitats present in Australia, ranging from desert and semi-desert to plains to mountainous areas to forest, even sometimes tropical rainforests. Preferred habitats, however, tend towards those that have a fairly varied topography including rocky areas, some open terrain and native woodlots such as Eucalyptus stands.

The wedge-tailed eagle is one of the world's most powerful avian predators. Although a true generalist which hunts a wide range of prey, including birds, reptiles and, rarely, other taxa, this species is by and large a mammal predator. The introduction of the European rabbit (Oryctolagus cuniculus ) has been a boon to the wedge-tailed eagle and they hunt these and other invasive species in large volume, although the wedge-tailed eagle otherwise generally lives off of marsupials, including many surprisingly large macropods. Additionally, wedge-tailed eagles often eat not inconsiderable amounts of carrion, especially while young. Wedge-tailed eagles tend to pair for several years, possibly mating for life.

This species generally constructs a large stick nest in an ample tree, normally the largest in a stand, and lays typically two, although sometimes 1 to 4, eggs. Usually breeding efforts manage to produce one or two fledglings, which after a few months more tend to disperse widely. Nesting failures are usually attributable to human interference such as logging activity and other alterations, which both degrade habitats and cause disturbances. This species is known to be highly sensitive to human disturbance at the nest, which may lead to abandonment of the young. Although historically heavily persecuted by humans via poisonings and shootings, mostly for alleged predation on sheep, wedge-tailed eagles have proved to be exceptionally resilient and have quickly rebounded to similar or even higher than pre-colonization numbers, thanks in part to humans inadvertently providing several food sources such as rabbits and large volumes of roadkills.

## Appearance

The Wedge-tailed eagle is the largest and most powerful Australian raptor. It has long, fairly broad wings, fully feathered legs, and an unmistakable wedge-shaped tail. Young eagles are mid-brown in color with slightly lighter and reddish-brown wings and head. As they grow older, their color becomes darker, reaching a dark blackish-brown shade after about 10 years. Adult females tend to be slightly paler than males.

## Distribution

Wedge-tailed eagles are resident throughout Australia, including Tasmania, in part of Papua New Guinea, and in Indonesia. They inhabit open woodland, savanna, heathland, grasslands, desert edge and semi-desert, subalpine forests, montane grasslands and mountain peaks, not-too-dense tropical rainforests, monsoon forests, dwarf conifer forests, some wetlands and coastal areas, though normally along the coasts they occur around plains somewhat away from the water. These birds favor remote or rough country, at least partially wooded and not uncommonly varied with some rocky spots as well as in shrubland. Wedge-tailed eagle may also be seen near towns and villages in suburban areas, in pasture areas, forestry clearings, and rolling farmland areas.

## Behavior

These impressive birds of prey spend much of the day perching in trees or on rocks or similar exposed lookout sites such as cliffs from which they have a good view of their surroundings. Now and then, they take off from their perch to fly low over their territory. During the intense midday heat, they often soar high in the air, circling up on the thermal currents that rise from the ground below. Each pair occupies a home range in which boundary they patrol and advertise their ownership with high-altitude soaring and gliding flights. They may defend their territory by diving into intruders. Wedge-tailed eagles may hunt singly, in pairs, or in small groups. Most prey is captured on the ground in gliding attacks or (less frequently) in the air. Wedge-tailed eagles are generally silent birds. Their commonest calls are high, rather thin whistles, sometimes transcribed as ‘I-see, I-see’ followed by a short descending ‘see-tya’. During the breeding season, they make various other whistles, yelps, squeals, and often rolling series.

## Diet

Wedge-tailed eagles are carnivores and scavengers. Most of their diet consists of rabbits and brown hares but they also feed on larger mammals such as foxes, feral cats, wallabies, small kangaroos, possums, wombats, koalas, and bandicoots. In some areas, Wedge-tailed eagles prey on birds such as cockatoos, Australian brushturkeys, ducks, crows, ibises, and even young emus. Reptiles are less frequently taken but can include frill-necked lizards, goannas, and brown snakes.

## Reproduction

Wedge-tailed eagles are monogamous and mate for years and even for life. They breed from July to December through much of their range, in New Guinea apparently from May on. As the breeding season approaches, pairs perch close to each other and preen one another. They also perform dramatic aerobatic display flights together over their territory. Sometimes, the male dives down at breakneck speed towards his partner. As he pulls out of his dive and rises just above her; she either ignores him or turns over to fly upside down, stretching out her talons. The pair may then perform a loop-the-loop flight. Wedge-tailed eagles usually nest in the fork of a tree between 1-30 m above the ground, but if no suitable sites are available, they will nest on a cliff edge. Before the female lays eggs, both birds either build the large stick nest or add new sticks and leaf lining to an old nest. Nests can be 2-5 m deep and 2-5 m wide. The female usually lays 2 eggs, which are incubated by both parents. After about 45 days, the chicks hatch. They are covered in white down up at first and are expectedly semi-altricial. At first, the male does all the hunting. When the chicks are about 30 days old, the female stops brooding them and joins her mate to hunt for food. Eaglets depend on their parents for food up to 6 months after hatching and leave only when the next breeding season approaches. First breeding is typically at 6 or 7 years old.

## Population

### Population threats

The main threat to Wedge-tailed eagles is habitat loss through extensive clearing and deforestation. Other important threats to these powerful birds include illegal persecution and collisions with powerlines.

### Population number

The IUCN Red List and other sources don’t provide the number of the Wedge-tailed eagle total population size. According to the Australian Government (Department of the Environment and Energy) resource, the total population size of the Wedge-tailed eagle in Tasmania is estimated at less than 1 000 birds. This includes less than 440 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.

### Ecological niche

Wedge-tailed eagles are top predators in their ecosystem; due to their diet habits, they control populations of introduced brown rabbits which make up a large part of these birds' diet.

## Fun Facts for Kids

Wedge-tailed eagles are one of the largest eagles in the world. They have the largest wingspan ever verified for an eagle.

Wedge-tailed eagles are highly aerial and soar for hours on end without wingbeat and seemingly without effort; they regularly reach 1,800 m (5,900 ft) and sometimes considerably higher.

The Wedge-tailed eagle is the only bird that has a reputation for attacking hang gliders and paragliders (presumably defending its territory). The birds are known to damage the fabric of these gliders with their talons and have also been reported to attack and destroy unmanned aerial vehicles used for mining survey operations in Australia.

The presence of a Wedge-tailed eagle often causes panic among smaller birds, and as a result, aggressive species such as magpies, butcherbirds, masked lapwings, and noisy miners aggressively mob eagles.

This beautiful bird is an emblem of Australia’s Northern Territory.

The West Coast Eagles AFL football club from Western Australia uses a stylized Wedge-tailed eagle as their club emblem. In recent years, they have had a real-life Wedge-tailed eagle named "Auzzie" perform tricks before matches.