The Great-winged Petrel or Grey-faced Petrel, Pterodroma macroptera, is a petrel. In New Zealand it is also known by its M?ori name oi and as a muttonbird.
There are two recognized subspecies of P. macroptera - P. m. macroptera and P. m. gouldi, the latter of which is endemic to New Zealand, and is often called the Grey-faced Petrel.
It breeds in the Southern Hemisphere between 30 and 50 degrees South with colonies on Tristan da Cunha, Gough Island, the Crozet Islands, the Prince Edward Islands, the Kerguelen Islands and on the coasts of southern Australia and northern New Zealand. It is a rare vagrant to the Pacific Ocean off the coast of California, United States.
The bird is completely dark brown except for a variable patch of white near the base of the bill, which is black. The petrel breeds on islands throughout the southern oceans. It is separated from Sooty Shearwater and Short-tailed Shearwater by the all-dark underwing, the thick, stubby bill, and different jizz. Also, the similar Flesh-footed Shearwater has a light, pinkish bill. Petrels in the genus Procellaria are larger and have a less bounding flight.