Northern Giant Petrel

The Northern Giant Petrel, Macronectes halli, also known as Hall's Giant Petrel, is a formidable seabird with a robust build. It boasts a wingspan stretching from 150 to 210 cm and an average body length of 90 cm. The plumage is predominantly grey-brown, with a paler hue gracing the forehead, face, and chin. This species exhibits sexual dimorphism, with males typically larger than females.

Identification Tips

Adult Northern Giant Petrels can be identified by their grey-brown plumage and lighter head. Their bill, measuring between 90 and 110 mm, is pinkish-yellow with a brown tip, and their eyes are a soft grey. Juveniles are darker, being almost entirely brown, and lighten with age. The Northern Giant Petrel can be distinguished from its southern counterpart by the bill's coloration; the Southern Giant Petrel has a greenish hue on the top of its bill.

Habitat

This pelagic bird is at home soaring over the vast Southern Ocean, often venturing north of the Antarctic Convergence Zone.

Distribution

The Northern Giant Petrel's range is extensive, encompassing the Southern Ocean and reaching northward to the coasts of Chile, Argentina, South Africa, New Zealand, and parts of Australia. Notable nesting sites include the South Georgia group, Chatham Islands, Kerguelen Islands, Crozet Islands, and Macquarie Island.

Behaviour

Northern Giant Petrels are aggressive foragers, known to consume carrion, fish, krill, squid, and other cephalopods. They are opportunistic, often trailing fishing boats for scraps and are known to engage in predation of other seabirds, including penguin chicks and injured adults.

Breeding

These birds commence breeding around the age of ten and establish colonies on islands, sometimes alongside Southern Giant Petrels. They initiate their breeding cycle six weeks earlier than their southern relatives.

Conservation status

The Northern Giant Petrel is currently classified as Least Concern by the IUCN. The population is on an upward trend, with estimates ranging from 17,000 to 21,000 mature individuals. Conservation efforts focus on continued population monitoring, research on movement and migration, and reducing bycatch in fisheries.

Diet and Feeding

The diet of the Northern Giant Petrel is varied, with a preference for carrion, including dead penguins and pinnipeds. They also consume pelagic organisms, with males favoring carrion and females more often foraging at sea. Their aggressive nature allows them to dominate other seabirds at food sources.

Similar Species

The Southern Giant Petrel (Macronectes giganteus) is the most similar species, with slight differences in bill color and size dimensions. The Northern Giant Petrel has a slightly longer bill and tarsus, while the Southern Giant Petrel has longer wings on average.