Antarctic Petrel

The Antarctic petrel (Thalassoica antarctica) is a striking seabird with a contrasting pattern of dark brown and white plumage. It possesses a brown head, sides, throat, and back, with the underparts, tail, and secondary wing feathers being predominantly white, tipped with brown. This medium-sized petrel has a wingspan ranging from 100 to 110 cm (39–43 in), a body length of 40–45 cm (16–18 in), and an average weight of 675 g (23.8 oz).

Identification Tips

When identifying the Antarctic petrel, look for its dark brown bill and grey feet, which complement its brown and white coloration. The large white spots on the wings are distinctive, as is the white belly and rump. In flight, the petrel's white tail and secondary wing feathers with brown tips are particularly noticeable.

Habitat

The Antarctic petrel is found in the Southern Ocean and on Antarctic islands, where it nests on snow-free cliffs and rock faces, both along the coast and on offshore islands. They have also been known to roost on icebergs and can be found up to 250 km inland.

Distribution

This species is most commonly seen in the Ross and Weddell Seas of Antarctica. During the late winter, some individuals may migrate to Australia or New Zealand, often due to being caught in severe storms.

Behaviour

Antarctic petrels are known to feed while swimming but are also capable of diving from both the surface and the air to depths of up to 1.5 m (4 ft 11 in) to capture their prey.

Breeding

Breeding occurs during October and November, with colonies sometimes exceeding 200,000 pairs. Each pair lays a single egg, incubated for 45–48 days, followed by a nestling period of 42-47 days. Both parents share incubation duties, and in some cases, female-female pairs have been observed. The hatching success rate ranges from 70-90%, with predation by South polar skuas and accidental egg loss being the main threats.

Diet and Feeding

The Antarctic petrel's diet primarily consists of Antarctic krill, fish, and small squid. They are adept at seizing food from the surface and can also perform plunge-dives to capture their prey.

Conservation status

With an estimated range of 77,500,000 km2 (29,922,917 sq mi) and a population of between 10 and 20 million adult birds, the Antarctic petrel is classified by the International Union for Conservation of Nature (IUCN) as a species of Least Concern.