Adult has gray crown, back, wings, and tail, with dark, M-shaped pattern on upperwings. Tail has a dark tip. Underparts are distinctive, with a white throat and breast, contrasting with a medium gray belly and vent. Bold black bars mark the leading edge of the mostly white underwings. At rest, gray flanks show above waterline. The face is characterized by a white supercilium, dark smudge around eye, and thick black bill. Cook's Petrel has mostly white underparts. Stejneger's Petrel has darker hood, contrasting with gray back. Also compare Buller's Shearwater.

Length: 36 (cm) Wingspan: 32 (cm)

Habitat:

Open ocean, rarely seen from shore.

Behavior:

Nests in burrows on islands, returning to nest site after dark. Strong flier over water.

Feeding:

Picks food from ocean's surface. Eats mostly fish, squid, and crustaceans.