This large, slender shearwater (4), with dark grey-brown plumage (5), flies effortlessly over the ocean with its long, narrow wings (4). The wings have a silvery lining (5), and a patchy white underside which may be conspicuous as it flies over the sea (4). Indeed, shearwaters are named for they way in which the wings, held stiff and motionless, skim the water's surface as they glide fast and low over the waves (7). Its long, blackish-grey bill has (4), like other shearwaters, a hooked tip and sharp blades, enabling it to efficiently handle slippery fish prey (6). Two tubular nostrils are situated on the upper bill, a unique feature of the Procellariiformes, a group of birds which includes the shearwaters, albatrosses and petrels (6). Infrequently heard in flight, the sooty shearwater is a noisy bird when ashore; its most common calls are a der-rer-ah or coo-roo-ah (3).