Masked Owl

The Masked Owl is Australia's largest Tyto owl.

Identification

The Masked Owl has three basic plumage forms: pale, intermediate and dark. The plumage pattern remains similar in each case. The facial disc is chestnut to white, edged with a darker ring and darker around the bill and below the eyes. The upper parts vary from blackish-brown to grey-white and are liberally spotted with grey and white. The underparts are rufous to white, speckled with dark brown. Sexes are similar in plumage, but the females are markedly larger and generally darker than the males. Young Masked Owls are white to cream in colour when first fledged. After the first year, they closely resemble the adults but may be more heavily streaked. Tasmanian birds are larger than those on the mainland. This species is the largest Tyto owl and the second largest of the nocturnal birds (night birds) in Australia (the largest is the Powerful Owl, Ninox strenua ).

Habitat

The Masked Owl inhabits forests, woodlands, timbered waterways and open country on the fringe of these areas. The main requirements are tall trees with suitable hollows for nesting and roosting and adjacent areas for foraging. Masked Owls are territorial, and pairs remain in or near the territory all year round.

Distribution

The range of the Masked Owl is a broad coastal band around most of mainland Australia and throughout Tasmania, and for the most part is less than 300 km from the coast. Population numbers are low on the mainland and several states give this species special conservation status. This owl was previously widespread in Tasmania.

Feeding and diet

Masked Owls feed mainly on small mammals, such as rodents, rabbits and bandicoots. Other prey animals include possums, reptiles, birds and insects, with hunting taking place in the early hours of night. The birds sit on low perches listening for prey which, once detected, is taken from the ground or from the tree branches.

Communication

A deep, rasping screech.

Breeding behaviours

Masked Owls breed when conditions are favourable and food items are plentiful. The nest is a bare chamber located deep in a tree hollow, which is lined with soil, sand or soft wood mulch. The eggs are incubated solely by the female, while the male provides the food. The female also tears up the food for the chicks. The young birds remain in the vicinity of the nest and are fed by the parent birds for a further month after fledging.

• Breeding season: Any time of the year
• Clutch size: 2 to 3
• Time in nest: 84 days

Conservation status

The Tasmanian subspecies of the Masked Owl, T. n. castenops, is listed as endangered in Tasmania, as a result of habitat loss. It is also included in the Federal Action Plan for Australian Birds 2000, with a recovery outline available as a PDF. Federally, two other subspecies are listed as vulnerable: the northern subspecies, T. n. kimberlii, and the Tiwi Islands' subspecies, T. n. melvillensis, while the southern subspecies, T. n. novaehollandiae, is listed as near threatened. The reasons for population declines vary and need further investigation, as many of the subspecies have not been abundant in the past and may require closer monitoring. These reasons may include: a possible decline in the availability of small mammals as prey, competition with other nocturnal birds of prey, decline in nest site availability, fire regime changes, land-clearing and forestry practices.

References

• Pizzey, G. and Knight, F. 1997. Field Guide to the Birds of Australia. Angus and Robertson, Sydney.
• Schodde, R. and Tideman, S.C. (eds) 1990. Reader's Digest Complete Book of Australian Birds (2nd Edition). Reader's Digest (Australia) Pty Ltd, Sydney.
• Strahan, R. (ed) 1994. Cuckoos, Nightbirds and Kingfishers of Australia. Angus and Robertson/Australian Photographic Index of Australian Wildlife, Sydney.