Newell's shearwater or Hawaiian shearwater (ʻaʻo), (Puffinus newelli) is a seabird in the family Procellariidae. It belongs to a confusing group of shearwaters which are difficult to identify and whose classification is controversial. It was formerly treated as a subspecies of the Manx shearwater (Puffinus puffinus) and is now often placed in Townsend's shearwater (Puffinus auricularis). It is endemic to the Hawaiian Islands. It is a fairly small shearwater, the upperparts are black with a brown tinge while the underparts are white. The dark colouration on the face extends below the eye and is sharply separated from the white throat. There is a white patch on the flanks, extending onto the sides of the rump. The underwings are mainly white with a dark border. The undertail-coverts have a black and white pattern and appear white in the field. The bill is dark grey or brown and the legs and feet are mainly pale pink. The bird flies low over the water on stiff wings with a mixture of short glides and periods of rapid flapping. It utters a donkey-like braying call around the breeding areas. Townsend's shearwater (P. auricularis) is very similar but has dark undertail-coverts, a shorter tail and a less sharp boundary between the black and white on the face.