Small black-and-white seabird with snappy wingbeats. Much smaller than most gulls. Prefers cold ocean waters; rarely seen from land. Typically found in more northerly latitudes, rarer further south. Contrastingly blackish above and white below, with white curling up behind eye. Underwing mostly white, sometimes with dark marks. Found singly or in small flocks, sometimes with other shearwaters. Flies low to the water, rarely arcing up high unless wind is strong. In Caribbean and western Atlantic, most similar to Audubon's Shearwater but shorter-tailed and darker-faced, with white under the tail.