The Wedge-tailed
Eagle, Aquila
audax,
is the biggest bird of prey
native to Australia, and is one of the
biggest Eagles in the world. In fact is one of the three types of
Eagle
I have heard being described at "The
biggest Eagle in the world".
The
other two were the Monkey
Eating
Eagle of the Philippines and the Golden Eagle of America. In fact, Wedge-tailed Eagle is
related to the Golden
Eagle
Female
Wedge-tailed Eagles are a little bigger than the males
and can weigh
over 11lb (5Kg), with a wing span of eight feet (2.3m). In captivity
this bird can live for fifty years although it is believed their
average life span in the wild is less than this.
The
Wedge-tailed Eagle is the most common of the world's eagles but not
nearly as common as it used to be.
There was a belief that the
Wedge-tailed Eagle killed a lot of lambs and a bounty was put on
them.
About Two
Million Eagles were killed before proper research was
finally done into the eating habits of the Wedge-tailed Eagle. It was
found that the Wedge-tailed Eagle rarely killed lambs. They do not even
like the taste much although they will often eat lambs killed be
other
things or which had died from other causes.
One
of the animals that does kill some lambs is the Fox. Foxes were found to
be part of the diet
of the Wedge-tailed Eagle.
Foxes are a major lamb killer. Killing the two million Wedge-tailed Eagles
may have actually allowed more Foxes to survive and kill more lambs
as
well as things like poultry.
A
major item of the diet of Wedge-tailed Eagles is Rabbits.
Possibly Australia
would have less Rabbits if the eagles
had been allowed to survive.
Eco
systems are complicated, and interference without proper knowledge
is
dangerous. It is sometimes
said that Australia's native animals cannot
compete with introduced animals.
While there is some truth in that, the
situation is often not quite so simple.
An example of where
introduced animal were able to eradicate a prolific introduced
species
was Rabbits on Kangaroo Island.
Some
early settlers deliberately
introduced Rabbits to Kangaroo
Island. Nowadays this would be
considered an act of extreme environmental vandalism, but ideas
have
changed. The native Goannas of the island found they liked the taste of
baby rabbits and they would go down the rabbit holes and eat the
babies. Now there are no
rabbits on Kangaroo
Island. Possibly if the
mainland native predators had not been deliberately killed, rabbits
would be in a better balance with the environment.
Wedge-tailed Eagles are now protected by law. Unfortunately not everyone obeys the law.
Other
things the Wedge-tailed Eagle eats are carrion, including animals
killed on the road, and sometimes larger prey. Dave Irwin related a
case of a large Kangaroo being killed by a Wedge-tailed Eagle
although
this is probably very rare.
A poultry Breeder I know, Norm Thomas, had one of his prized Rhode Island Red Roosters
taken by a Wedge-tailed Eagle.
Sources
for this article include: the extremely informative "Birds of Prey"
show by Dave Irwin on Kangaroo
Island. Dave Irwin is the man
in the
picture holding an eighteen year old female Wedge-tailed Eagle. I do
not know if he is any relation to the late Steve
Irwin.
See http://www.tourkangarooisland.com.au/wildlife/tours.aspx for more details
