The three key species of threatened forest owls that live in areas of Victorian State Forest that VicForests operate within are thePowerful Owl (Ninox strenua), Masked Owl (Tyto novaehollandiae novaehollandiae) and Sooty Owl (Tyto tenebricosa).
In order to protect these nocturnal birds, Owl Management Areas (OMAs) have been created across the forest landscape. These areas have been assessed as the most suitable habitat for each species and are excluded from harvesting.
In addition to these special owl conservation areas, if a threatened owl nest or roost site is detected in an area planned for harvest, VicForests ensures that these sites are protected in line with the appropriate legislative requirements.
During 2011-12, VicForests Pre-harvest Fauna surveys detected several threatened forest owls, including numerous breeding pairs of Powerful and Sooty Owls, and adaptive management plans were put into place to appropriately protect these special breeding pairs.
Powerful Owl (Ninox strenua)
Powerful Owls are the largest owls in Australia, with adults sized between 60cm to 65 cm (Birdlife Australia 2012). They can be distinguished by their large, forward facing, yellow eyes. Adults are distinguishable by mottled dark grey-brown feathers on their upper body, white below with bold grey brown chest barring, feathered legs up to the tarsus (shins) and dull yellow feet (DSE, 2004).
This nocturnal species is found in forested landscapes throughout Victoria, while they are also known to inhabit urban areas around Melbourne. Powerful Owls favour moist forests such as dense gullies, which are most likely to contain older trees with hollows that serve both as their nesting sites and home to most of their prey.
They tend to nest during winter (between June and July), and lay eggs (usually 2) which take between 35 to 38 days to hatch (Birdlife Australia, 2012).
Powerful owls feed on a range of different prey items including arboreal marsupials such as possums and gliders, as well as other bird species.
This species is listed as threatened under the Flora and Fauna Guarantee Act (1988), and there are a range of protective requirements for the management of this species in State Forest.
Masked Owl (Tyto novaehollandiae)
These nocturnal birds are very secretive in their behaviour, often making them hard to detect and study (Birdlife Australia, 2012). Masked Owls can be distinguished by their blackish-brown facial mask surrounding their predominately pale face.
Male Masked Owls are generally smaller in size than females, with average sizes of 37cm and 47cm respectively (DSE, 2003). Masked owls have a stocky, often crouched posture, strong heavy feet and feathered legs.
Masked Owls are known to inhabit a range of forested landscapes, while they prefer to nest in hollows that form in large old trees. This species are also known to prefer forests that are composed of a dense understorey or ecotones, with dense and sparse ground cover. They can roost in caves, sinkholes or crevices and cliffs in areas of little vegetation cover.
Their breeding period is from April to November and their diet depends mainly on the vegetation and climatic conditions they live in which determines the kinds of prey available (Birdlife Australia, 2012).
Sooty Owl (Tyto tenebricosa)
The Sooty Owl is a medium-large owl that is dark in colour. It has a round facial disk, short round wings, short tail and large black eyes. The upper body is sooty black colour while their breast is lighter in colour, with speckles throughout.
The female is known to be larger than the male, 44cm to 51cm for females and 37cm to 43cm for males. DSE (2003) reports that Sooty Owls are confined in the central eastern part of Victoria, stretching over to the far eastern coastal areas.
This species tends to breed in autumn to winter and with spring peaks. They nest mainly in large old tree hollows and sometimes in caves ledges or crevices on rock faces. Within the state their habitats ranges from rainforests to tall open forests and open forest of different ecological vegetation classes and trees species (DSE, 2003).
Department of Sustainability and Environment (2003) Masked Owl, Tyto novaehollandiae novaehollandiae, Action Statement, Flora and Fauna Guarantee Act 1988, Victoria, Australia
Department of Sustainability and Environment (2004) Powerful Owl, Ninox strenua, Action Statement, Flora and Fauna Guarantee Act 1988, Victoria, Australia.
Department of Sustainability and Environment (2003) Sooty Owl Tyto tenebricosa, Action Statement, Flora and Fauna Guarantee Act 1988, Victoria, Australia