Scientific name: Thalassoica antarctica
Antarctic petrels have chocolate-brown and white wings with broad white trailing edges. The tail is white with a brownish-black tip. They are a medium-sized petrel with a 100–110 cm wing span, with an average mass of 675 g.
Distribution & abundance
Antarctic petrels are mainly confined to the vicinity of the pack-ice, icebergs, ice floes, Antarctic seas and the Antarctic continent. Flocks are characteristically seen sitting on the ridges of icebergs. In late winter, they are occasionally recorded from Australia and New Zealand.
Antarctic petrels are gregarious at sea and roost on icebergs in flocks comprising thousands of birds. Breeding colonies range from a few nests to more than 200 000 pairs.
The population is believed to be stable and unaffected by human activities.
Conservation status: least concern
Antarctic petrels return to their nest in October to November and lay one elongated ovoid egg. They usually nest in clefts, crevices and on ledges on sloping rocky cliffs in snow-free areas. The incubation and nestling periods are 45-48 days and 42-47 days respectively.
Fledglings from the same colony may remain together in flocks. Two chicks banded in the same colony were recovered six years later, 780 km from the colony.
Hatching success ranges between 70 and 90% at colonies studied at the Haswell Islands and the Windmill Islands. Egg loss was mainly due to eggs rolling out of nests and subsequently freezing. Egg predation by south polar skuas also occurs.
Diet and feeding
The diet of Antarctic petrel consists of krill and other crustaceans, euphausiids, pteropods, amphipods, cephalopods and small fish.