The Australian boobook (Ninox boobook), which is known in some regions as the mopoke, is a species of owl native to mainland Australia, southern New Guinea, the island of Timor, and the Sunda Islands. Described by John Latham in 1801, it was generally considered to be the same species as the morepork of New Zealand until 1999. Its name is derived from its two-tone boo-book call. Eight subspecies of the Australian boobook are recognized, with three further subspecies being reclassified as separate species in 2019 due to their distinctive calls and genetics.
The smallest owl on the Australian mainland, the Australian boobook is 27 to 36 cm long, with predominantly dark-brown plumage with prominent pale spots. It has grey-green or yellow-green eyes. It is generally nocturnal, though sometimes it is active at dawn and dusk, retiring to roost in secluded spots in the foliage of trees. The Australian boobook feeds on insects and small vertebrates, hunting by pouncing on them from tree perches. Breeding takes place from late winter to early summer, using tree hollows as nesting sites. The International Union for Conservation of Nature has assessed the Australian boobook as being of least concern on account of its large range and apparently stable population.