A small gray-and-white petrel with a dark hood, a bold dark “M” pattern across the upperwings, and a distinctive bold black underwing pattern. Very variable. A pale morph resembles Gould’s Petrel, while a distinctive sooty-brown dark morph shows exceptionally bold underwing markings. Pale morph separated from Gould’s Petrel by its much bolder underwing pattern and its hood, which often meets below the neck, creating a full collar. Silent at sea.