11. Giant Petrel
(Macronectes giganteus)
Plate 6

Two subspecies:

Northern Giant Petrel (M. giganteus halli)

Southern Giant Petrel (M. giganteus giganteus)

The northern subspecies (halli) cannot easily be distinguished at sea from dark phased individuals of the southern race (giganteus), and the two subspecies are therefore discussed together.

Field Characters: 213/91. A large, dark brown, albatross-like bird, equivalent in size to a mollymawk. Its comparatively short, wedge-shaped tail, pale horn bill and bulky wide-winged appearance distinguish it from the Light-mantled Sooty Albatross (10). page 25

Fig. 8: Light-mantled Sooty Albatross (Phoebetria palpebrata) off the Antipodes Islands. Note the long pointed tail.
—Photo: Mannering and Associates

Fig. 9: A group of Giant Petrels (Macronectes giganteus) quarrelling over food.
—Photo: F. C. Kinsky

page 26 Individuals of the northern subspecies (halli) are generally all dark brown or greyish brown with individually varying amounts of paleness on the face and head. In the southern subspecies (giganteus) two colour phases occur—a dark phase, similar to the northern race, but with a conspicuously pale head and neck, and a white phase with only a few scattered, dark feathers (cf. Figs. 11a-11c, Pl. 6). The iris of adult birds in both races is pale grey. Juvenile birds of both races appear uniformly sooty brown and have dark eyes.

Bill pale greenish horn colour, or light buff with a conspicuous, long nasal tube. Feet greyish black.

Differs from juvenile Wandering Albatross (1) by its dark underwing and smaller size, and from Light-mantled Sooty Albatross (10) by its dark back, shorter and broader wings, wedge-shaped tail as well as its more bulky appearance.

The stiff-winged soaring flight is not as sustained as with the mollymawks and is often interspersed with slow, flapping wingbeats. Giant Petrels follow ships for offal and congregate around fishing vessels. They also readily enter harbours and assemble at outfalls from freezing works and sewer outlets.

Circumpolar in distribution. The northern race breeds locally at Chatham, Stewart, Antipodes, Auckland, Campbell and Macquarie Islands, whereas the southern race breeds locally only at Macquarie Island. Widespread and abundant in New Zealand waters throughout the year.