Southern boobook smallest owl on the Australian mainland, the southern boobook is long. The nominate subspecies is the largest. It has short, rounded wings and a short tail, with a compact silhouette in flight. Southern boobooks on the Australian mainland follow Bergmann's rule, in that birds from cooler and more southerly parts of the range tend to be larger. Thus, birds from the Canberra region weigh around while those from the Cape York Peninsula and Broome are around . Females tend to be a little larger and heavier than males, with males weighing and females . The southern boobook has generally dark
Southern boobook boobook" in 1801, writing about it in English, before giving it its scientific name, taking its species epithet from a local Dharug word for the bird. The species description was based on a painting by Thomas Watling of a bird—the holotype—in the Sydney district in the 1790s. John Gould described "Athene marmorata" in 1846 from a specimen in South Australia; this is regarded as a synonym. German naturalist Johann Jakob Kaup classified the two taxa into subgenus "Spiloglaux" of a new genus "Ieraglaux" in 1852, renaming "S. boobook" to "Ieraglaux (Spiloglaux) bubuk". In his 1865 "Handbook to the Birds of