Effect of plumage wear on field identification of White-naped Petrels, Pterodroma cervicalis

Abstract

White-naped Petrels, Pterodroma cervicalis, are all but confined to Macauley Island, Kermadec Islands, for breeding. Observations of adults and fledglings in the hand and at sea in May revealed consistent and dramatic differences in the appearance of birds in fresh (fledgling) and worn (adult) plumage. The very dark dorsal plumage of adult White-naped Petrels in worn plumage has not previously been described.