Tuatara: Volume 21, Issues 1 and 2 (New Zealand Albatrosses and Petrels: an Identification Guide)
39. Mottled Petrel — (Pterodroma inexpectata) — Plate 16
39. Mottled Petrel
Field Characters: 74/33. A medium-sized gadfly petrel with conspicuously patterned undersurface. Upperparts frosty grey with darker open ‘M’ marking across wings and back. The dark grey crown and dark areas around eye contrast with the mottled forehead and white face. Chin, throat, upper breast and undertail coverts white, lower breast and belly dark grey. Underwing white with conspicuous broad black leading margin, extending diagonally over the inner underwing coverts.
Bill short, black. Feet flesh-coloured with dark outer parts and webs.
Differs from the Black-winged Petrel (38) and other smaller gadfly petrels with conspicuously patterned underwings, by the dark grey patch on lower breast and belly.
A solitary species with typical gadfly petrel flight. consisting of fast, high arcing and sustained gliding. Does not follow ships.
Summer breeder on islands in Foveaux Strait, off Stewart Island and at the Snares. Migrates to North Pacific for southern winter.