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
Anatomical terms of bone or Superior pubic ramus. Ramus may also be used to refer to nerves, such as the ramus communicans. A "facet" refers to a small, flattened articular surface. A "line" refers to a long, thin projection, often with a rough surface. "Ridge" and "crest" refer to a long, narrow line. Unlike many words used to describe anatomical terms, the word "ridge" is derived from Old English. A "spine", as well as referring to the spinal cord, may be used to describe a relatively long, thin projection or bump. These terms are used to describe bony protuberances in specific parts of the