Audubon's shearwater underparts are white, as is the head below eye level. The iris is dark, the feet are dull pink with a black wash and black toenails, and the bill is grey, darker towards the tip, and with a pinkish hue. Males and females look alike. Immature birds do not have a distinct plumage, while the nestlings are covered with down feathers, grey above and whitish on the belly. It can be confused with the Manx shearwater ("P. puffinus"), which has white undertail coverts and in direct comparison a longer bill. Other similar-looking species are usually completely allopatric, though the largely
Buller's shearwater blackish also; the two black areas do not meet at the hand however; the area between them is a rather light grey, under bright light it may appear almost white. With the bird facing upwards, the pattern gives the impression of a broken black "M", with light grey interspersing areas. The underside is bright white; on the head the upperside's grey extends town to eye height and the white cheeks may shine up conspicuously, as in the smaller shearwaters of "Puffinus sensu stricto". The rectrices are blackish and the tail is wedge-shaped; bill and iris are dark. Fledged juveniles already