Southern boobook age. Brushtail possums ("Trichosurus" spp.) and introduced cats and rats raid the nests for nestlings and eggs, and raptors such as the brown goshawk ("Accipiter fasciatus"), grey goshawk ("Accipiter novaehollandiae"), Australian masked owl ("Tyto novaehollandiae"), and probably powerful owl ("Ninox strenua") seize young birds. Juvenile southern boobooks are at greater risk after bushfires and have perished after being tangled up in dodder ("Cassytha") or bidgee-widgee ("Acaena novae-zelandiae"). The southern boobook generally preys on mice, insects, particularly nocturnal beetles and moths, and birds the size of a house sparrow ("Passer domesticus"). A higher proportion of its diet is invertebrates compared with
Southern boobook August to October in Queensland, from September to November in New South Wales and southern Western Australia, July to September in central and northern Western Australia, in October and November in Victoria, and in September to December in South Australia. The southern boobook nests in holes in trees between 1 and 20 m (3–70 ft) above the ground. The holes are generally vertical, and mostly in eucalypts, though other trees such as coast banksia ("Banksia integrifolia") have been recorded. Some sites are reused by the species for up to 20 years, especially if broods have been successfully raised in them