Satin Bowerbird (Ptilonorhynchus
violaceus): The Bowerbirds are a remarkable family found
only in
Australia and New Guinea. They build bowers where displays and mating occur.
The bowers are not nests. They are usually shallow and saucer-like,
constructed of twigs.
There are two types of bower. Avenue-bowers are a double row of twigs and
grass constructed, at ground level, on a platform of sticks (see left hand
image). Maypole-bowers are single or double columns of sticks constructed
around saplings. Males build the bowers.
Of the seven Australian Bowerbirds only the Golden Bowerbird builds a
maypole-bower.
Male Bowerbirds collect natural or artificial objects and arrange them
around the bower. There appears to be a correlation between the colours of
the collected objects and the plumage of the bower-builder.
Satin Bowerbirds are between 280-320 millimetres in length. Males are a
striking glossy blue-black with a bluish-white bill, blue eyes and
greenish-yellow legs. Females are olive-green to blue-grey above and the
wings and tail tawny brown. The female bill is dark brown, eyes purplish
blue and legs dull greenish yellow.
Immature males, from the first to third years, resemble females. Four year
old males have a paler bill and blue feathers appear in the plumage. Males
gain full plumage when they are about seven years old.
In autumn and winter Satin Bowerbirds are often observed in large flocks
composed of females, immature males and a few blue males. They often raid
fruit trees and will pull seedlings out of the ground. This is an activity
that does not endear Satin Bowerbirds to gardeners.
Breeding season is usually between July and February. At this time immature
birds assist in the construction of “training” bowers. Adults are more
solitary and males build and maintain bowers and also displaying. They spend
a great deal of time collecting objects for display around the bower.
Females are left with the tasks of building nests and feeding young.
Satin Bowerbirds collect blue, greenish-blue or yellow objects. This ties in
with the colour of their plumage as mentioned above. Close to habitation
most collected objects are artificial. Blue clothes pegs and biro tops
figure prominently in Satin Bowerbird collections.
We have also observed bluish-green, exotic Cypress foliage displayed near a
bower in the Blue Mountains of New South Wales.
The bower illustrated was discovered in a rhododendron garden in the
Southern Highlands of New South Wales. All the objects collected were
man-made.
Satin Bowerbirds occur along the coast and nearby ranges in southern
Queensland, New South Wales and Victoria. There is also an isolated
occurrence in northern Queensland.
Wildlife