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
Arripis commensal relationship between the Australian salmon and the birds is noted to be especially strong in such species as the white-fronted tern, ("Sterna striata"), fluttering shearwater, ("Puffinus gavia"), and Buller's shearwater, ("Puffinus bulleri"). The baitfish made available by the Australian salmon's herding behaviour may also be important to the reproductive success of winter-nesting birds; the decline of the Australians salmon stocks has evoked concern for these bird species, some of which – such as the fairy tern, ("Sterna nereis") – are endangered Aside from seabirds, the Australian salmon are also important in the diets of cetaceans, such as killer whales