Huge, Vulnerable, Resident Breeders… Powerful Owls

By Keith Hutton on September 6, 2011 in Other

Owls are among the most easily recognised birds. All are predators and most hunt at night. Relatively few people have actually seen an owl but the birds are familiar because of the folklore associated with them. For centuries they have been linked with wisdom, witchcraft and sorcery, and the recent popularity of the Harry Potter movies has enhanced their reputation and increased our fascination with them.

There are six species of owls that have been recorded over the years in the Sydney region but only two, Southern Boobook and Powerful Owl, are residents present throughout the year that breed regularly.

The Southern Boobook is moderately common in suitable habitat but not often seen; it is also known as a ‘Mopoke’ to many people because of its persistent call, which is often heard at night in late winter and spring. Powerful Owls are much less common and the status of Barn Owls in Sydney is uncertain.

Boobooks and Powerful Owls roost in the thick foliage of mature trees, whereas Barn Owls often roost in hollows, where they are much more difficult to detect. They are, however, irruptive nomads that respond to build-up of prey numbers by prolific breeding and dispersal, and consequently may occur in Sydney or anywhere in Australia from time to time.

Barking, Sooty and Masked Owls have all been recorded in the Sydney region too, but they are scarce even in suitable specialised habitat, and are highly unlikely to be encountered.

Powerful Owls are awesome birds; big males are over 65cm tall with a wingspan of around 1.4 metres. They are dark grey-brown above with pale mottling and bars, and their underparts are buff-white marked with bold dark chevrons. They roost singly, in pairs or in family groups high in a shady tree in the daytime, and often one of the birds has a partly eaten possum or flying fox held tightly in the heavy, powerful talons of one massive yellow foot. When approached they glare down menacingly with large yellow eyes at intruders.

They occur along the south and southeast coastal areas of Australia, mostly in forests and woodlands, but they are also seen roosting in parks and gardens in the Sydney region where there are believed to be somewhere between twenty and thirty pairs.
It is not known for sure where they are breeding, and there is a need to identify critical roosting and breeding requirements, as well as locations of important areas requiring protection. As a consequence of this, and their vulnerability in NSW, a monitoring program has been set up to study the lifestyle and habitat of Powerful Owls in the Sydney region.

Powerful Owls have been found roosting in the Botanic Gardens. In the Eastern Suburbs, Centennial Park and Bronte Gully would be worth a look for roosting activity, even though suitable nesting trees may not be present and preferred prey of Common Ringtail Possums are probably not in sufficient numbers to support breeding.

For further information or observations, email birdsinbackyards@birdsaustralia.com.au or feedback@thebeast.com.au.