The powerful owl (Ninox strenua) is Australia’s largest owl. With big yellow eyes and an impressive wingspan of up to 140cm, they’re a fabulous sight if you’re lucky enough to see one. However, getting a glimpse at these birds is no easy task; despite their size, the powerful owl is quite the hide-and-seek expert.
The Powerful Owl citizen science project is changing that by enlisting the public to help researchers keep eyes and ears on them. The observational data is then used to track down hollows and monitor breeding populations to inform conservation initiatives.
“Despite being a really big bird with a really obvious call, it’s really hard to find them,” explains Rob Clemens, powerful owl project coordinator.
“They’ve got a huge home range. It varies from 50 km2 to only a few kilometres. You might have one on your hills hoist one night, and then never see it again.”
That’s where citizen science comes into the picture.
“In New South Wales over the last 10 years, we’ve been able to find a couple hundred pairs,” says Beth Mott, Powerful Owl project officer in NSW. “From that we monitor their breeding success and are then able to communicate with land managers about what kinds of things they can do to protect their local pairs.”
The species’ range covers south-eastern Queensland to South Australia (excluding Tasmania), mostly in large patches of forest. However, the powerful owl has been reported to be moving into the suburb and cities of Sydney, Melbourne and Brisbane.
With large swathes of their habitat destroyed by last summer’s bushfires, Clemens says now is the time to get involved.
“Fires often have devastating impacts on trees that are 100 to 500 years old — the trees that forest owls nest in,” he says. “[It’s] now more important than ever to identify remaining owl breeding hollows.”
Like a good game of hide and seek, certain clues can give away an owl’s location, all of which are useful for researchers.
“With the observational data, we can start searching for hollows,” Clemens says. “Once we’ve got these hollows located, we can start monitoring breeding success, we can get a good handle on breeding density and how they’re travelling.
“We can also look at the kind of characteristics of forests that are associated with successful breeding. Often though, land managers are not aware that powerful owls are in their forests, so it helps to simply let them know ‘hey, you actually have powerful owls in this forest’.”
The first key thing to look for is the remains of prey. Things like bones and fur aren’t easily digestible and will be coughed up as pellets. Juveniles also tend to drop their prey, so there will be even more mess around. You can also keep an eye out for large patches of whitewash left behind. The main giveaway, Clemens says, is their calls.
“During the early breeding season between March and April, they’re much more vocal as they’re setting up territories. In August and September though, chicks are emerging from their hollows.
“The chicks are absurdly cute. It’s a great time to go out at dusk and listen for them as they make a very distinctive call.”
Getting started is as easy as getting outside around sunset. While walking, keep an eye out for any of the signs of the powerful owl, and if you see or hear one, log the details using the BirdData app, or by visiting the Powerful Owl website.
“Learning where powerful owl populations are found is the first step to conserving them,” Clemens says.