Boobook owls: St Kilda’s silent assassins

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By Fam Charko 

‘Silent death’ may not be the first phrase that comes to mind while watching an unassuming boobook owl sitting on a tree branch in the St Kilda Botanic Gardens.

They do not have attention grabbing features like some other owl species that may have protruding ears, immaculately snow-white plumage, and/or an impressive size.

So, one would think they can’t do much damage.  In fact, Southern boobooks are the smallest owl species on mainland Australia.

Tiny as they are, these little owls are quite wicked; they are known to eat beetles, moths, mice – the usual owl fare but also surprisingly bush rats, bats, house sparrows, parrots, and even bigger animals like possums and rabbits.  Subspecies of this predator live just about everywhere, including in densely populated areas like St Kilda.  

Every winter for at least the last three years, a boobook has been taking up seasonal residence in the gum tree next to Elwood Primary School’s garden, in its own Hotel Elster Creek.

Every night during its stay, it enjoys Melbourne’s famous gastronomic delights in its favourite restaurant, the compost heap. One by one, the local mice and rats fall victim to this connoisseur of Victorian vermin.  

Boobooks in Ripponlea Estate, the local parks and in many of the backyards in Port Phillip do the same. 

Many fly all the way from Tasmania to stay the winter, feasting on the abundant mainland prey.

The Tasmanian boobooks are slightly smaller than their Victorian counterparts, have golden eyes, and lighter marks on their face.

Bird watchers have seen them gather in great numbers at Cape Liptrap in Gippsland at the end of winter, waiting for favourable weather conditions to safely make the crossing back to the island en masse. 

Rather than the charismatic Hedwig, the big snowy owl owned by the famous wizard-in-training Harry Potter, boobooks look more like Errol, Ron Weasley’s small family owl: a mottled white and brown, wearing an expression of perpetual surprise in its yellow eyes. 

We tend to forget that among our local wild neighbours, these owls are the most feared predators of the night sky.  

If you are a mouse, moth, or sizable beetle that likes to hang out at night, then you face their carnal prowess. 

They are arboreal stalkers, hiding in leafy shadows, always watching with large eyes perfectly adapted to seeing movement in the dark.

When they spot their prey, they swoop down fast and utterly soundless.  

Like other owls, boobooks can fly silently because of their unique feather adaptations: where other birds create sounds when they fly (think of a pigeon’s high-pitched ‘woop-woop-woop’sound as it takes off), these owls have flight feathers that are serrated like a comb.

These serrations reduce noisy turbulence by breaking up and re-angling the air currents around their wings, directing them through the soft, downy underside of the wings, where any remaining sound frequencies are absorbed.

That’s why that ringtail possum on your backyard fence never stood a chance.

Boobooks nest in hollow trees and with a distinct lack of those in Port Phillip, local bird watchers have not seen them breed in our area. 

But if we provide the owls with suitable nesting spaces, by preserving large trees and hollowed out dead trees, maybe some visitors won’t feel the need to fly back to Tasmania every spring.

Think of it, we may benefit from their expert pest control for free!  

Youth Wildlife Ambassador Gio Fitzpatrick’s guide to watching boobooks

  • Best time to see boobook owls in St Kilda and surrounds: February to August, with July being the peak month.
  • Best time of day: early night, or just before sunrise.
  • Best places to spot owls: around Elwood Primary School, the Elster Creek foreshore reserve and the start of St Kilda Pier
  • Best weather: still, dry winter nights. You won’t see them when it’s windy.
  • Best way to spot them: look for their silhouettes flying silently against the night sky, or spot them sitting in trees on dead branches without leaf cover.
  • Best way to help boobooks: do not use poison to kill vermin around your house; rather use mechanical traps. Also, hang an owl nesting box in your garden (call the EcoCentre for more information)

 With Gio Fitzpatrick

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