Powerful owl - Ninox strenua

[OldGreenVulture]

Powerful Owl
Scientific name: Ninox strenua
Similar species:
Rufous Owl


The Powerful Owl is Australia's largest owl.

Identification
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-shaped 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. Powerful Owls are the largest of the Australian nocturnal birds (night birds).

Habitat
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. Will sometimes be found in open areas near forests such as farmland, parks and suburban areas, as well as in remnant bushland patches. Needs old growth trees to nest.

Distribution
The Powerful Owl is endemic to eastern and south-eastern Australia, mainly on the eastern side of the Great Dividing Range, from south-eastern Queensland to Victoria.

Satellite View
Seasonality
Sedentary.

Feeding and diet
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.

Communication
Deep, double hoot: 'woo-hoo', with male's generally deeper than female's.

Breeding behaviours
The Powerful Owl mates for life (over 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 over a year.

Breeding season: April to September
Clutch size: 2, rarely 1
Incubation: 38 days
Time in nest: 55 days
Conservation status
The Powerful Owl is adversely affected by land clearing, but can live in fragmented habitats such as farms or suburban areas. Sometimes killed by cars. Young birds are sometimes killed by foxes, cats or dogs.

References
Higgins, P.J. (ed) 1999. Handbook of Australian, New Zealand and Antarctic Birds, Volume 4 (Parrots to Dollarbird). Oxford University Press, Melbourne.
Morcombe, M. 2000. Field guide to Australian Birds. Steve Parish Publishing.
Simpson, K and Day, N. 1999. Field guide to the birds of Australia, 6th Edition. Penguin Books, Australia.

australianmuseum.net.au/learn/animals/birds/powerful-owl/?gclid=EAIaIQobChMIw5itkufQ5QIVFR4rCh3n3gUfEAAYASAAEgLGIPD_BwE

[Eaglehawk]

Citizen scientists to help look for secretive powerful owls in southern Queensland

By Shelley Lloyd
Updated Friday at 09:17
First posted Friday at 06:13


A powerful owl sits on a branch in the Mount Coot-tha Reserve in Brisbane in 2018.  (Supplied: Rodney Weidland)

Citizen scientists will soon take to bushland around southern Queensland looking for Australia's largest and most elusive owl.

Key points:

• The $100k government funding allows Birdlife Australia to buy acoustic monitors and engage volunteers to do surveys to find where the owls are living
• Despite their size, powerful owls are very hard to spot as the birds inhabit dense vegetation
• The money funds three years of research and the first acoustic monitors will be deployed in March at the start of the owl breeding season

They will be armed with acoustic monitors to try and record the secretive powerful owl to help find and protect its threatened habitat.

Birdlife Australia has been given almost $100,000 by the State Government to find where the threatened owl is breeding to protect it from rapid development in south-east Queensland.
Powerful owl project officer Dr Robert Clemens said despite their size, the owls were very hard to spot.
"Powerful owls are ridiculously hard to find because they're very quiet and very secretive," Dr Clemens said.


 Powerful owl - Credit: Nick Bradsworth, Deakin University

"They hang out in really dense vegetation, so they're really hard to spot despite being this really huge owl.
"The easiest way to find these owls in your area is to listen for their distinctive calls, particularly just after dusk or in the wee hours of the morning."
Dr Clemens said powerful owls had a slow, double-note "whoo-hoo" call that was soft, but very strong and resonant.
"It takes of lot of patience before you actually hear or see them — we hope to overcome this problem by having lots of ears and eyes looking for them," he said.


The first acoustic monitors will be deployed in March next year at the start of the owl breeding season.  (Supplied: Nick Bradsworth)

Volunteers to help do surveys

Dr Clemens said the state funding will allow Birdlife Australia to buy acoustic monitors and engage volunteers to do surveys to find where the owls are living.
"They're a very small device, not much bigger than a deck of cards, with a little microphone and you can program them to listen at specific times of day," Dr Clemens said.
"You just strap this device to a tree and you come back in a couple of months and take out all that data.
"We're just starting to unpack where the owls are in the greater Brisbane area.
"When we started this project last year we thought there might be around 30 pairs of powerful owls and now we think there might be upwards of 150 [in the greater Brisbane area]."


Despite their size, the owls are very hard to spot.  (Audience submitted: Antonia Hayler)

Protected habitat needed

Dr Clemens said they would use the information to lobby the State Government and local councils to set aside protected habitat for the owl.
"Because they're so secretive, often [land] clearing and other things will happen and you just won't be aware that you're also taking out powerful owl habitat because we don't know where they are in the landscape," he said.
"We're really trying to work with planners and managers how we can conserve these birds, so in future you can take your grandkids to see powerful owls out at Mt Coot-tha or wherever they may be.
"Every month we get about 1,000 people moving to south-east Queensland, so we're making a lot of decisions about how we change the landscape to make room for more of us, and we just want the powerful owl to be thought about in that process."


Volunteers will do surveys to find where the owls are living.  (Supplied: Nick Bradsworth)

Dr Clemens said the money would fund three years of research and the first acoustic monitors would be deployed in March next year at the start of the owl breeding season.
Queensland Environment Minister Leeanne Enoch said she had seen the powerful owl project first-hand and the funding will ensure threatened species were protected.
Ms Enoch said this funding was part of the Queensland Government's $18 million Community Sustainability Action Grants Program.
"The Palaszczuk Government is committed to ensuring our threatened species are protected, and this funding will fund on-the-ground projects that help restore important habitat and conduct important research into some of Queensland's most vulnerable flora and fauna," Ms Enoch said.


Powerful owls have a slow, double-note 'whoo-hoo' call that is soft, but very strong and resonant. (Supplied: Nick Bradsworth)

www.abc.net.au/news/2019-10-18/powerful-owl-citizen-scientist-acoustic-monitors/11611526?section=science&sf221719693=1