With a wingspan reaching more than two metres, the Wedge-tailed Eagle is Australia’s largest bird of prey and one of the biggest eagles in the world.
The Wedge-tailed Eagle is one of 24 diurnal (day-active) raptor species in Australia. Like other birds of prey, it has a hooked bill and large talons. It can weigh 4kg, measure 1m from head to tail-tip and has a wingspan of up to 2.3 m (females are larger than males).
Young birds have brown feathers that become progressively darker as the bird ages; mature adults are dark brown to black with white and bronze feathers on their neck and wings. The bird’s long powerful legs are feathered to the base of the toe.
Have you seen a Wedge-tail Eagle take off from the ground? You might remember the bird’s heavy flight, its slow, powerful wing beats. Once on the wing, the bird soars with ease, circling at great heights, to altitudes of 2,000m! From below you can see its flight feathers, stretched like fingers, and the wedge-shaped tail that gives the species its common name.
Wedge-tailed Eagles feature in many dreaming stories for Aboriginal Australians: for example, the eagle Bunjil is an important creator being for the Kulin people of central Victoria. For the Kaurna People of the Adelaide Plains, the eagle’s claw takes the form of a constellation known as Wilto (the Southern Cross). The name Aquila audax, means bold eagle in Latin.
Where do Wedge-tailed Eagles live?
The Wedge-tailed Eagle has an extremely large range: it’s found throughout mainland Australia, Tasmania and southern Papua New Guinea.1 It prefers wooded areas and open forests, but can be found in coastal and alpine regions. It’s seldom seen in rainforests or coastal heaths.
The species is considered the most common of the world's large eagles.2 While it’s of Least Concern under the International Union of Nature (IUCN) Red List of Threatened Ecosystems, it’s fully protected in all Australian states and territories. The Tasmanian subspecies (Aquila audax fleayi) is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999.3
Wedge-tailed Eagles are monogamous: they mate for life. Breeding pairs are territorial, and will defend their hunting ground and their large, impressive nests. Built of sticks and lined with leaves, their nests can measure 2m across, 3m deep and weigh more than 400kg!
The nests are so large that smaller birds, like finches, can nest in the underside, benefiting from the protection from predators offered by the eagles! Nests are usually built in the tallest tree in the vicinity, commanding an impressive view of their territory. In parts of Australia where there are no large trees available, the eagles will create nests in shrubs, on telegraph poles, on cliff faces and even on the ground. A pair may have up to 10 different nests within their territory, and will often use a different nest in different years.
Eggs are laid in response to local food availability. After 45 days of incubation, the chicks emerge, covered in white down. While two to three eggs may be laid, the parents typically rear only one young per clutch. When food is scarce, the larger chick may kill and eat its smaller sibling.
The bulk of the Wedge-tailed Eagles’ diet is made up of mammals – predominantly rabbits (which can make up to 92% of their diet), hares, kangaroos and wallabies – but they may also consume large birds (e.g. waterfowl) and lizards.
Eagles sometimes kill lambs, but this is only a small percentage of their total prey. A large source of their diet is carrion: they scavenge on road kill and carcasses. They will hunt live prey and can work in pairs or in groups, especially when hunting large prey like adult kangaroos. One bird can lift 50% of its body weight!
In the early to mid 1900s, farmers believed that Wedge-tailed Eagles killed sheep and lambs. A bounty was paid for their destruction, leading to the death of tens of thousands of eagles. It’s now understood that eagles only attack sick or dead lambs, and have little real effect on the sheep industry.4 However, illegal killing and persecution does remain a threat in some areas from time to time.
Now, the main threats to Wedge-tailed Eagles are tree-clearing and the loss of nesting sites; indirect poisoning from Dingo baits; secondary poisoning (eating rabbits laced with pindone, for instance); collision with overhead wires, fences, and with vehicles while eating road kill. The Tasmanian subspecies is endangered due to the disturbance and lost of nesting sites: at least 40% of forests and dry woodlands have been cleared in Tasmania since settlement.5
What's Bush Heritage doing?
Wedge-tailed Eagles are often seen soaring majestically above virtually all of our reserves and partnership properties. Most reserves also contain suitable nesting habitat and a visit to a "wedgie nest” is always a highlight.
Importantly, most of our Tasmanian reserves (e.g. Liffey Valley Reserves: Coalmine Creek, Drys Bluff, Liffey River, Oura Oura) provide habitat for the endangered Tasmanian subspecies of the Wedge-tailed Eagle.
We're looking after the species by protecting their habitat, ensuring these impressive eagles have ample nesting sites… and plenty of space to spread their wings!
1. IUCN Red List
2. Australian Museum
3. Australian Government Dept of Environment & Energy: Species Profile
4. Australian Government Dept of Environment & Energy: Species Profile
5. Australian Government Dept of Environment & Energy: Species threats