Southern boobook their upperparts. The tips of their feathers are white and fluffy, remnants of the nestlings' down. These are worn away over time, persisting longest on the head. The feathers of the head, neck and underparts are fluffier overall. Immatures in their second and third year have plumage more like adults, though their crowns are paler and more heavily streaked. On mainland Australia, it could be confused with the barking owl or the brown hawk-owl ("Ninox scutulata"), a rare vagrant to the northwest, although the southern boobook is easily distinguished by its squat posture and distinctive pale border to its face
Australasian gannet with white overall. They have dark brown bills, bare facial skin and eyes, and dark grey legs and feet. Australasian gannets take 2-5 years to gain adult plumage. Over this period, the upperparts and underparts gradually whiten and the crown and nape become buff-coloured. However, there is great variation in the age that mature plumage is seen. This species is distinctive, and only likely to be confused with species that do not generally share its range. The Cape gannet is a rare vagrant to Australasian waters and has an all-black tail, while the masked and red-footed boobies are generally restricted