31 October 2011

Wedge-tailed Eagle – Aquila audax subsp. audax

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Wedge-tailed Eagle – Aquila audax subsp. audax

Most Australians are familiar with the Wedge-tailed Eagle as it occurs throughout much of the country including Tasmania, although there it is subsp, fleayi, whilst all mainland ones are subsp. audax. The only bird that could be confused with this species is the White-bellied Sea-Eagle, which can be seen around all coastal waters. The adults are easy to distinguish, with the Sea-eagle having a white belly and the wedge-tail being dark brown or black. However the juvenile Sea-eagle also has a brown belly, but can be identified by the broader wings that are held stiffly upright in a wide V shape, whilst the Wedge-tail has a much flatter (almost horizontal) carriage when soaring.

In the Esperance region of Western Australia this bird is not uncommon, being widely distributed, but especially around large granite outcrops that are common around the coast and inland to the north and northeast of the town. Each inland outcrop would have at least one pair of birds who defend it against other wedge-tailed eagles, even if they do not actually nest on the rock, but probably do so in larger trees that often grow nearby. Their wingspan is to 2.3 metres (7’ 6”) so are impressive looking birds when they come to look you over.

The above young bird (perched on the rock) was very intrigued by my presence and had probably not seen a person before and certainly not on its rock, as we were situated in remote bush around 80 km from the closest road. However, I could not get closer than 30 metres before it would lift off and glide a little further away. The soaring one was photographed from the top of Mt Ney 75 km (45 miles) NE of Esperance, who had also come to check me out, but was not interested in getting closer.

Wedge-tailed Eagles do hunt, but will also scavenge dead animals and are a common sight along outback highways where they feed on roadkill and unfortunately often become causalities themselves, as they are slow to lift off and unless into a strong wind, can be hit by fast moving vehicles. Wedge-tailed Eagles are more often seen on clear but windy days, when they will glide effortlessly over large areas in search of food. The eagles generally pair for life and do not seek another mate unless one dies.