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 treated Australian and New Zealand boobooks, along with several taxa from Indonesia and Papua New Guinea, as one species—"Ninox novaeseelandiae"—with 16 subspecies. In his 1968 book "Nightwatchmen of the Bush and Plain", Australian naturalist David Fleay observed that the boobooks from Tasmania more closely resembled those of New Zealand than those from mainland Australia, though he followed Mees in treating them as a single species. The southern boobook was split from the Tasmanian boobook and morepork in volume 5 of the "" in 1999, though several authors, including Australian ornithologists Les Christidis and Walter Boles, continued to treat the three