The Antarctic petrel nests in dense colonies (6). One of the largest known is located inland at Svarthamaren in Queen Maud Land, Antarctica where up to 255,000 breeding pairs have been observed. There are 35 known breeding colonies, mostly in East Antarctica, but there are probably more to be discovered (7).
Although generally considered to be monogamous, female Antarctic petrels will sometimes mate with a neighbouring male. Due to the high proportion of females in some populations, not every female is able to breed each season. Occasionally a breeding female will be joined by an unsuccessful female providing the opportunity to improve its parenting skills (8).
The female Antarctic petrel lays one egg (9) in the last ten days of November (10) and the egg hatches in early January (6) (10). After hatching, the adults take turns to remain at the nest while the other forages for food (3).These foraging trips may cover large distances of up to 3000 kilometres (11). Chicks fledge in late February to early March (10).
Plunging into the water to grab its prey or seizing it from the surface of the water, the Antarctic petrel feeds on fish, Antarctic krill (Euphausia superba) and occasionally squid (5). Inland colonies feed mostly on crustaceans, whereas birds living on pack ice feed mainly on fish (11). In some colonies, chicks may eat proportionally more fish than their parents, because fish provide slightly more energy and protein than krill and considerably more calcium, which is required for growth (12).
Adult Antarctic petrels generally have high survival rates (9). Although there are no available data concerning hatching or fledgling success in this species, it is known that south polar skuas (Stercorarius maccormicki) predate eggs and chicks, targeting nests that are less sheltered (13).