Powerful Owl in Boronia Park


Powerful OwlClick to enlarge image

Powerful Owl Image: Arthur Chapman
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Fast Facts

  • Classification
    Species
    strenua
    Genus
    Ninox
    Family
    Strigidae
    Order
    Strigiformes
    Class
    Aves
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    50 – 60 cm

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.

Baby Powerful Owls

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.

Powerful owls’ unlikely home in city suburbs leads to call for citizen scientists to track activity

Posted 

Australia’s largest owl, the majestic and endangered powerful owl, is finding an unlikely home in the green areas of our city suburbs, and the Australian public is being called on to help track the nocturnal birds.

Birdlife Australia has launched the Powerful Owl Project (POP), with a raft of information about the owl, including audio of its call and an app to help citizen scientists map the general location and movement of individuals in metropolitan areas.

Identifying the powerful owl may be easier than assumed — it’s the only owl in south-eastern Australia with a classic double ‘hoo-hoo’ call.

The predatory bird stands up to 60cm tall, and has piercing yellow eyes, reddish white plumage, and long yellow legs with big talons, making it especially attractive to bird watchers and photographers.

While its ability to adapt to an urban environment appears encouraging, the stark reality is that there are only around 5,000 known individuals in the wild.

The majority are found in New South Wales but they have also been identified in Victoria, South Australia, and Queensland.

Making a home in the suburbs

Powerful Owl Project manager Dr Beth Mott can be found most days in the urban field, binoculars in hand, on the lookout for newly-reported powerful owl nesting and roosting locations.

“Powerful owls are undergoing a real resurgence at the moment and unlike many threatened species, they actually do very well in urban spaces, and particularly the greater Sydney basin,” Dr Mott said.

“Data we’ve collected from our citizen scientists shows us that most powerful owl breeding in urban spaces is going on within 50 metres of the urban boundary.

“[They] really love to be in those small green fingers that project into the suburbs: gullies, creek lines, parks.

“They need large trees with hollows for their nests that you tend to find standing proudly around suburban streets.”

Dr Mott said the birds also found the suburbs to be great hunting grounds, more so than the forest.

“They’re moving into our own backyards, and catching possums on the power lines, and sometimes sitting on the guinea pig pen and looking for a bit of dinner,” she said.

Studies in urban areas have shown that there has been an average breeding success rate of 76 per cent over the past three years, offset by high rates of mortality in young chicks.

In addition, an increasing loss of breeding adult birds through car strikes means a natural upswing in the powerful owl population could be followed by a future crash, Dr Mott said.

Magpie with talons?

The powerful owl in the urban environment has recently received attention due to the proposed Mt Coot-tha Botanic Gardens zipline project in Brisbane.

Owls have been nesting in the Mt Coot-tha Reserve for the past 30 years and following concerns the owls could potentially swoop patrons, the proposed zipline has been shifted 100 metres from the owls’ nesting tree.

Dr Beth believes the zipline’s location would have posed a greater threat to owls than patrons, and downplays the risk of birds attacking.

“They are a large bird [and] there’s been some talk that they could be dangerous to people,” she said.

“We’ve found that less than 1 per cent of the population does the swooping behaviour, and that’s just for 6 weeks during nesting season.”

She said that behaviour was associated with stress that birds faced within the urban area, such as encroachment.

“Because people love to see them, the powerful owl is exposed to a high frequency of photography, for example, and have been known to abandon their nest when disturbed too much,” Dr Mott said.

Umbrella species

The urban green spaces being used by the powerful owl typically exist outside of protected spaces like national parks and reserves, so managing disturbances like fire, urban expansion, and bush regeneration is regarded as essential in supporting powerful owl breeding in the suburbs.

Regarded an umbrella species, when protected the powerful owl will in turn protect a suite of other wildlife, including small birds, frogs, echidnas and threatened nocturnal birds like sooty and masked owl.