Behaviour and Diet
They are highly aerial, soaring for hours on end without wingbeat or effort, regularly reaching 1,800 metres (5,900 ft) and sometimes considerably higher. The purpose of this very high flight is unknown. Their keen eyesight extends into the infrared and ultraviolet bands. This helps them spot prey and allows them to see rising thermals, which they can use to gain altitude while expending little energy.
Most prey is captured on the ground in gliding attacks or (less frequently) in the air. Choice of prey is very much a matter of convenience and opportunity: since the arrival of Europeans, the introduced rabbit and Brown Hare have become the primary items of the eagle's diet in many areas. The Wedge-tails can eat almost anything of a suitable size, live-caught or as carrion.
They display considerable adaptability, and have sometimes been known to team up to hunt animals as large as the Red Kangaroo, to cause goats to fall off steep hillsides and injure themselves, or to drive flocks of sheep or kangaroos to isolate a weaker animal. Wedge-tailed Eagles may also kill young calves.
Carrion is a major diet item also: Wedge-tails can spot the activity of Australian Ravens (sometimes known as crows) around a carcass from a great distance, and glide down to appropriate it. Wedge-tailed Eagles are often seen by the roadside in rural Australia, feeding on animals that have been killed in collisions with vehicles.
This impressive bird of prey spends much of the day perching in trees or on rocks or similar exposed lookout sites such as cliffs from which it has a good view of its surroundings. Now and then, it takes off from its perch to fly low over its territory. During the intense heat of the middle part of the day, it often soars high in the air, circling up on the thermal air currents that drift up from the baking ground below. Each pair occupies a home range, which may extend as little as 9 square kilometres to more than 100 square kilometres. Within this home range lies a breeding territory around the nest. The eagle patrols the boundary of this home range and advertises its ownership with high-altitude soaring and gliding flights. It may defend its territory by diving on intruders. Adults are avian apex predators and have no natural predators but must defend their eggs and nestlings against nest predators such as corvids, currawongs, or other Wedge-tailed Eagles and in Tasmania there is often conflict with the white-bellied sea eagle over nest sites .
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