Tuatara: Volume 21, Issues 1 and 2 (New Zealand Albatrosses and Petrels: an Identification Guide)
Pterodroma Leucoptera
Pterodroma Leucoptera
Two subspecies:
Gould's Petrel (P. leucoptera leucoptera)
Collared Petrel (P. leucoptera brevipes)
The two subspecies can be distinguished from each other at sea and are therefore dealt with separately. For Collared Petrel see 58.