White-chinned Petrel Procellaria aequinoctialis

Common, rather large dark petrel of the Southern Ocean; regular migrant north into Humboldt Current. Usually looks wholly blackish with a pale, ivory-colored bill—the white chin is often just a few feathers and frequently is difficult to see in the field, although it can be more extensive, especially on Atlantic and Indian Ocean birds. White-chinned is obviously larger than dark-billed Sooty Shearwater and much smaller than giant-petrels, which have huge pale bills. Pale bill tip distinguishes White-chinned from similar Westland and Parkinson’s Petrels, which have dark bill tip.