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 southern boobook is a mainly nocturnal species, though may be active at dawn and dusk. It is heard much more commonly than seen, being particularly vocal in breeding season. The characteristic two-note "boo-book" call or hoot can be heard up to away, the second note generally lower in pitch than the first. Calling takes place from sunset through till dawn, generally with a peak in the two hours after dusk and just before dawn. It can continue for several hours. The male's hooting is higher pitched and of shorter duration, and is heard much more commonly than that of the