Morepork they conceded the two were easily distinguishable in appearance, so maintained the three as subspecies; the Tasmanian boobook only diverged by 2.7% from the other two, while the powerful and rufous owls diverged by 4.4% from each other. Leading from this, the southern boobook was split from the Tasmanian boobook and morepork in volume 5 of the "", however several authors, including Les Christidis and Walter Boles, contested that the data had been misinterpreted from the Norman study, which had not sampled any Australian mainland boobooks at all. They treated the three taxa (southern, Tasmanian boobooks, and moreporks) as a
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