Globally there are 250 species of owls; of this, 11 species are found in Australia. They are the Barn Owl, Barking Owl, Powerful Owl, Rufous Owl, Masked Owl, Morepork, Greater Sooty Owl, Lesser Sooty Owl, Eastern Grass Owl, Southern Boobook and Christmas Island Boobook.

Owls have long sparked our imaginations; their haunting night calls, silent flight, extraordinary hearing and deadly eyesight has seen them embedded in different cultures as symbols for magic, wisdom and mystery.

Bush Heritage

Characteristics

Owls are masters at silent flight. Their soft, uniquely structured feathers are serrated, affecting the movement of air over the wings. Additionally, the velvety surface of the feathers absorbs any sound made by flapping wings. Their silent flight allows them to pounce on prey with no warning. Owls have incredibly superior eyesight and hearing, and their forward-facing eyes grant them excellent depth perception, which is necessary for low-light hunting.

They can rotate their head 270 degrees, a vital asset when their eyes are fixed and cannot move within their sockets. In addition, their ears are asymmetrical on their head (at different heights on the side of their face), so the sounds reach each ear at different times, aiding them in identifying the exact location of their prey. Owls also have a facial disk around their eyes; this helps focus sounds to their ears, so they hear even the quietest sounds.

Behaviour

Owls are nocturnal (hunting only at night) though some are active at dawn and dusk. They are found in every state of Australia and vary significantly in size; they range from the smallest (Southern Boobook at 36cm tall and around 175g) to the largest (Powerful Owl at 60cm tall and 1.5kg). They live in various habitats, from snowy mountainous areas to deserts, from open wet forests to woodlands and grasslands. The Powerful Owl is territorial and has been known to attack humans, though most are solitary and shy.

Diet

Owls live on a diet of small to medium-sized mammals, birds and insects. Like most birds, they cannot chew and eat their prey whole or will tear off pieces with their powerful, sharp beaks if unable to do so. Some owls, such as the Sooty Owl, eat mainly tree-dwelling mammals such as sugar gliders and small possums. Others prefer land-dwelling lizards or mammals. Like other raptors, owls regurgitate the non-nutritious party of their prey. Several hours after eating, they will produce a pellet from their gizzards of fur and bone. They will then be ready to eat again.

Threats

Habit loss is the biggest threat to Australian owls as they rely on old-growth trees with hollows for nesting and breeding. These hollows take hundreds of years to form. Sadly, land clearing and bushfires are wiping out the hollows at an alarming rate. Another significant threat is secondary poisoning from eating prey such as foxes, feral cats, rabbits and rodents that have taken the bait. Poachers are also a concern, both as live specimens and eggs.

Status

No Australian owl species is on the national threatened species list. Some populations, however, such as the Powerful Owl in Victoria, are vulnerable, and the Masked owl is endangered in SA, Tasman and Victoria.