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
Bannerman's shearwater Bannerman's shearwater Bannerman's shearwater ("Puffinus bannermani") is a seabird in the Procellariidae family formerly considered conspecific with Audubon's shearwater ("Puffinus lherminieri"). Little is known of this species other than that it breeds in the Volcano Islands in the Ogasawara Group to the southwest of Japan and doesn't seem to range far from this area. The species population size has not been estimated but is assessed to be decreasing. Not much is known about this species and more research is required to obtain an understanding of its ecology. Based on the ecology of closely related species, "P. bannermani" is thought likely