Northern giant petrel

Appearance

The northern giant petrel averages 90 cm in length, with a range of 80 to 95 cm , possessing a wingspan of 150 to 210 cm . Size is somewhat variable and this species is broadly the same size as its southern sister species. The largest-bodied colony is in the South Georgia Islands, where 56 males averaged 4.9 kg and 43 females average 3.72 kg . The smallest-bodied are on the Chatham Islands, where 19 males averaged 3.66 kg and 21 females averaged 2.83 kg . Overall, weight for the species can range from 2.5 to 5.8 kg . Its plumage consists of grey-brown body with lighter coloured forehead, sides of face, and chin. Its bill is between 90 and 110 mm long, being slightly longer on average than the southern giant petrel, and is pinkish yellow with a brown tip, and its eyes are grey. The tarsus of the northern giant petrel is slightly longer on average than the southern species as well, but the southern has longer wings on average. The juvenile of this species is completely dark brown and lightens as it ages. It can be differentiated from the similar coloured southern giant petrel by the top of the bill, which on the southern is green.

Naming

''Macronectes giganteus'' can be broken down as ''makros'' a Greek word meaning "long" or "large" and ''nēktēs'' meaning "swimmer". Northern giant petrel starts with "northern" referring to their habitat being further north than their counterpart the southern giant petrel, and "petrel" refers to Saint Peter and from the story of him walking on water, which refers to how they run on top of the water as they are getting airborne.

Status

Overall, their population stands between 17,000 and 21,000 mature birds, based on a 2001 estimate. This number has been increasing over the last two decades, though it was forecasted to decrease. This increase has allowed the IUCN to downgrade them from near threatened to least concern. Recent surveys have shown that most locations are increasing in numbers except for the Crozet Islands. This is probably due to increases in fish waste, better control on longline fishing, and more carrion from fur seals.

Currently, this bird is listed on CMS Appendix II and ACAP Annex 1. Future plans are to maintain the surveys and counting of individuals, researching movement and migrations, continuing the trend of lowering the bycatch deaths by current means and if needed newer measures through CCAMLR, CMS, and FAO.

Habitat

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 with the South Georgia group with 4,500 pairs. They also nest on some of the Chatham Islands, Kerguelen Islands, Crozet Islands, Macquarie Island and others. Their overall occurrence range is 82,600,000 km2 .

Reproduction

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.

Food

The northern giant petrel feeds mainly on carrion from penguins and pinnipeds, as well as krill, offal, cephalopods, and discarded fish and waste from ships. During the breeding season, males eat more carrion than females with the females feeding on pelagic sources.