Shearwater, medium-sized, dark brown. flies with short, sharp beats and has slender, uneven wings. Depending on the illumination, its variable underwing pattern might be difficult to judge. It is often rather dark with a less pronounced silvery flash than Sooty Shearwater. Very much like the Sooty Shearwater. Look for a little shorter bill and a more rounded head in short-tailed birds, which are lighter and have more curved wings.