Petrel (Northern giant petrel (Macronectes halli)
Species: M. halli
Binomial name: Macronectes halli
Common name: Northern giant petrel, Hall's giant petrel, Pangurunguru, Nelly, stinkpot, stinker, Antarctic giant petrel. giant fulmar, stinkpot, sea vulture.
Macronectes halli (Northern giant petrel) is a large predatory seabird of the southern oceans. They are pelagic and fly throughout the Southern Oceans north of the Antarctic Convergence Zone, and north through Chile, Argentina, South Africa, and half of Australia. They nest on islands of South Georgia (Georgias del Sur), Prince Edward Islands (South Africa), Crozet and Kerguelen Islands (French Southern Territories), Macquarie Island (Australia), Auckland, Campbell, Antipodes and Chatham Islands and, historically, on islets off Stewart Island (New Zealand). Their overall occurrence range is 82,600,000 km2.
The northern giant petrel averages 90 cm in length, with a weight > 4.5 kg., and a wingspan of 150 to 210 cm. Size is somewhat variable and this species is broadly the same size as its southern sister species. It has a variable plumage from white to grey-brown; the Southern giant is separated from the Northern species by having a green, not brownish tip to their huge bill (90-105 mm).
The northern giant petrel feeds mainly on carrion from penguins and pinnipeds (seals), as well as krill, offal, cephalopods, and discarded fish and waste from ships.
Birds start breeding at an average age of ten years and breed on islands in colonies, which they share with the southern giant petrel. They breed six weeks earlier than their counterpart though.
The Northern giant petrel comes from the Procellariiformes order, which is referred to as tube-nosed seabirds, due to their unique nose structure. They have nasal passages that attach to the upper bill called naricorns. As a member of the Procellariiformes, the Northern giant petrel produces a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. The proventriculus is the narrow glandular first region of a bird's stomach between the crop and the gizzard. This oil is used against predators as well as an energy rich food source for chicks and for the adults during their long flights. Finally, they also have a salt gland that is situated above the nasal passage and helps desalinate their bodies, due to the high amount of ocean water that they imbibe. It excretes a high saline solution from their nose.