Powerful Owls (Ninox strenua) are the largest of the
Australian nocturnal birds (night birds) and are listed as vulnerable under the
NSW Threatened Species Conservation Act 1995.
The Powerful Owl is a large owl with a relatively small head
and a rounded tail. It is dark grey to dark grey-brown above, with white
barring, and off-white below, with distinctive dark V-shape chevrons.
The eyes are yellow, set in a dark grey/brown facial mask.
The legs are feathered and the yellow to orange feet are massive, with sharp
talons. The sexes are alike but the female is smaller, with a narrower head.
Juvenile birds are downy white on the head and underparts. The underparts are
sparsely streaked and they have much shorter tails than the adults.
The Powerful Owl is found in open forests and woodlands, as
well as along sheltered gullies in wet forests with dense understoreys,
especially along watercourses. They will sometimes be found in open areas near
forests such as farmland, parks and suburban areas, as well as in remnant
bushland patches. Powerful Owls need old growth trees to nest.
The Powerful Owl has been sighted in a few locations
in lower Prospect Creek and Cabramatta Creek, where there are still remnant
mature trees remaining available for them in which to roost.
The Powerful Owl is a carnivore, eating mainly medium to
large tree-dwelling mammals, particularly the Common Ringtail Possum (Pseudocheirus peregrinus)
and the Great Glider. It will also take roosting birds and sometimes small
ground-dwelling mammals such as rabbits or small marsupials. It forages mainly
in trees, swooping down on prey and taking prey with its feet.
The Powerful Owl mates for life (more than 30 years in some
cases) and pairs defend an all-purpose territory year-round. The male prepares
the nest, which is usually a vertical hollow in a large old tree, and provides
the female and young with a constant supply of food during the early part of
the nesting period. The female incubates the eggs and broods the young,
emerging later in the nesting period to hunt for food as well. Young birds
remain with the parents for several months after fledging and may stay within
their parents' territory for more than a year.
The Powerful Owl is adversely affected by land clearing, but
can live in fragmented habitats such as farms or suburban areas. Sometimes they
are killed by cars. Young birds are sometimes killed by foxes, cats or dogs.
This video shows a few different behaviours of the Powerful
Owl. One favourite is the chick nonchalantly sitting on the brick wall while it
gets dive bombed by a Noisy Myna.
Again we see how mature trees that have developed hollows
for habitat are so important for conserving our native wildlife.
Keep in mind if you have a mature tree that you see as a
safety risk, you can have work done to reduce the canopy and deadwood pieces
and leave the tree ‘totem’ in place with hollows intact. See a picture below of
a tree ‘totem’ that was created in Council’s Community Nursery. Some local
ducks have taken a liking to it!
Council is going to start installing wildlife habitat signs
on trees that have been preserved in this way to educate the wider community on
why we need to keep as many hollows as we can.
