59. Herald Petrel
(Pterodroma arminjoniana heraldica)
Plate 21

Field Characters: 90/36. A large to medium sized gadfly petrel, slightly larger but very similar to the Kermadec Petrel (27). Differs from the latter primarily in its underwing pattern, in which the sub-terminal white wing flash extends on to the greater underwing coverts to form an irregular white line (cf. Fig. 27d, Plate 12, with Fig. 59, Plate 21). At close range the lack of the Kermadec Petrel's white primary shafts can be confirmed. This species also has light, dark and intermediate colour phases, making its distinction from the Kermadec Petrel difficult at sea.

Bill black; feet pale flesh-coloured with dark toes and webs.

Flight consists of the usual high arcing and swooping low to the sea's surface, accompanied with powerful wingbeats.

Widely distributed in the tropical Pacific. Not recorded from New Zealand. The nominate subspecies occurs in the Caribbean.