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 cm to 110 cm wingspan, and an average mass of 675 g.
Distribution and abundance
Antarctic petrels are found near the pack ice, icebergs, ice floes, Antarctic seas and the Antarctic continent. Flocks are often 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. They roost on icebergs in flocks that have thousands of birds. Breeding colonies range from just 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. Incubation lasts 45 to 48 days, and the nestling period is 42 to 47 days.
Fledglings from the same colony may remain together in flocks. 2 chicks banded in the same colony were recovered 6 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 freezing. Eggs are also eaten by south polar skuas.
Diet and feeding
The diet of Antarctic petrel consists of krill and other crustaceans, euphausiids, pteropods, amphipods, cephalopods and small fish.