The powerful owl is Australia's largest owl species reaching a body length of up to 65cm (2ft) long and having a wingspan up to 140cm (4.6ft) across. An average weight for the species would be 1050-1700g (37-60oz). Females tend to be smaller than males.
Despite having a large body the head of the powerful owl is relatively small. At the end of the body is a rounded tail.
Across their back the powerful owl is colored dark grey or dark grey-brown. On the underside they are colored off-white and have dark v-shaped chevrons running across it. Their patterning allows them to blend in with the forest.
Their eyes are colored yellow with a large black, circular pupil. These give them good vision at night when they are most active. Around the eyes are dark patches of feathers.
Powerful owls have yellow or orange feet with large talons to help catch prey. The feathers cover the legs to the feet.
The powerful owl is a carnivore. Their large size gives them the ability to eat large prey items such as flying foxes, possums, greater gliders, smaller birds and land dwelling mammals such as marsupials.
Introduced species such as rabbits have increased the prey available to them.
Prey is caught by swooping down and grabbing it with the powerful talons.
Often large prey items are not eaten till the night after they are captured and the owl will be seen roosting with one foot holding the prey item for a whole day.
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Australia is the native home of the powerful owl. Here they can be found along the east coast from Queensland down through New South Wales, the ACT and in to Victoria.
These birds are found in eucalypt forests, open forest and woodland. They will be found in sheltered gullies and along watercourses.
They require an old growth tree to nest in.
As possums are able to live alongside humans and represent the main food source for the powerful owl this species is increasingly seen in cities.
Breeding takes place from late March to September. Males seeking a mate for the season will begin to call in late February.
A pair of powerful owls will mate for life. This pair will defend their territory year round.
Males are responsible for preparing the nest. This is created in a vertical hollow inside of a large hollow log.
Once the male completes the preparations the female will enter the nest and deposit her clutch of eggs. Two eggs are typically laid though one may be laid. These eggs are close to being spherical and are colored white.
The male will provide a supply of food to the female and the chicks while she incubates them. This incubation period will last for 38 days. The female will provide almost constant brooding of the chicks for the first four weeks.
By 7 to 8 weeks old the chicks are ready to take their first flight.
Young birds may remain within their territory for as long as a year.
The powerful owl is active by night. During the day they will roost in a tree in an area which provides ample shade.
Males and females each have a unique call with his being deeper. The call sounds like 'whoo-hoo.'
Predators and Threats
Introduced predators such as the red fox, dog and cat have reduced the numbers of powerful owls.
Large parts of the former range of the powerful owl has been made uninhabitable due to clearing for agriculture.
The removal of old growth forests and large trees has reduced the availability of nest hollows. Hollows which are suitable for a powerful owl pair to nest in will take hundreds of years to form.
Poisoning, vehicle strike and disturbance are other threats to the survival of the powerful owl.
Greg Sharkey, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Aviceda, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
CSIRO, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons
Morcombe, M., 2003. Field Guide To Australian Birds. Archerfield, Qld.: Steve Parish Pub.
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Lewis, D., 2020. Powerful Owl (Ninox strenua) – Information, Pictures, Sounds – The Owl Pages. [online] The Owl Pages. Available at: <https://www.owlpages.com/owls/species.php?s=3080> [Accessed 17 April 2021].
The Australian Museum. 2021. Powerful Owl. [online] Available at: <https://australian.museum/learn/animals/birds/powerful-owl/> [Accessed 17 April 2021].