The Wedge-tailed Eagle or Arrawa (Aquila audax) is a very large Australasian raptor and the most common large eagle to be found in the world. It has long, fairly broad wings, fully feathered legs, and a distinctive wedge-shaped tail. Both because of its size – it is one of the largest birds in the world – and because of the pointed tail, it can be identified at a glance as a “Wedgie” even by the non-expert.
As with many raptors, the female is larger than the male and averages around 4.2 kg, and sometimes as much as 5 kg. Males are typically around 3.2 kg. Length varies between 0.9 and 1.1 meters, wingspan from 1.8 to 2.5 meters.
Juvenile Wedge-tailed Eagles are mid-brown in color with slightly lighter, reddish-brown wings and heads and wings. As they near adulthood, they become gradually darker, reaching a dark blackish-brown shade after about ten years. Adult females tend to be slightly paler than males.
Wedge-tails are found throughout Australia and southern New Guinea in almost all habitats, though they tend to be more common in lightly timbered areas and open country in southern and eastern Australia.
They are expert fliers and can soar for hours on end without wingbeat or effort, regularly reaching 6000 feet (2000 m) and sometimes considerably higher. The purpose of this very high flight is unknown. It is however known that their keen eyesight extends into the infrared and ultraviolet bands. This helps them to easily spot prey and also 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. Convenience and opportunity are major factors in choice of prey: since the arrival of Europeans, the introduced rabbit and Brown Hare have become the mainstay 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 substantial 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.
Carrion is a major diet item also: Wedge-tails are able to spot the activity of ravens around a carcass from a great distance, and glide down to steal it.
The Tasmanian sub-species is currently considered threatened and was once subject to a bounty as it was believed to have predated on livestock.