|Habitat and Ecology:
Behaviour Breeding populations in the southern part of this species's range are migratory, post-breeding flocks migrating long distances to winter off the southern coasts of South America and South Africa (del Hoyo et al. 1996). Those populations that winter in South America arrive from mid April and depart again from mid-October, during which time the adults moult their flight feathers (del Hoyo et al. 1996). Some populations around Antarctica remain close to their breeding grounds all year round however and moult on ice-floes or icebergs on open water (del Hoyo et al. 1996). The species breeds between November and December although the exact timing varies depending on climate and food availability (del Hoyo et al. 1996). It usually nests in small loose colonies of 5-20 pairs although it may often nest singly and has been known to nest in larger colonies of up to 1,000 pairs (del Hoyo et al. 1996). It forages in inshore waters singly or in small flocks (Urban et al. 1986, del Hoyo et al. 1996) and in the winter communal roosts of 10-1,200 individuals often form (Urban et al. 1986). Habitat Breeding The species breeds on rocky areas very near the coast or a short distance inland (Higgins and Davies 1996), showing a strong preference for nesting sites that are inaccessible to ground predators (del Hoyo et al. 1996). Suitable nesting habitats include vegetated or unvegetated rocky islets, offshore stacks, coastal cliffs, gravel, rocky and sandy beaches and sparse scrubland (del Hoyo et al. 1996). The species forages in inshore waters up to 200 m from the shore and in coves, bays, inlets, harbours and off estuaries, especially where there are large forests of kelp (Higgins and Davies 1996). Non-breeding Outside of the breeding season the species moves to the nearest area of open water or to pelagic zones far from land (Higgins and Davies 1996) where it forms communal roosts on ice-floes and icebergs (Higgins and Davies 1996) and forages in patches of unfrozen inshore water or in open water along the edge of ice. More migratory populations also winter off the temperate southern coasts of South America and South Africa with adjacent cold water currents (Higgins and Davies 1996), inhabiting rocky headlands and beaches (del Hoyo et al. 1996). Diet Its diet consists predominantly of small fish although it also takes polychaetes (del Hoyo et al. 1996), molluscs (Higgins and Davies 1996) (e.g. limpets) (del Hoyo et al. 1996), crustaceans (e.g. euphausiids and amphipods), insects (del Hoyo et al. 1996) and algae (Higgins and Davies 1996). Breeding site The species nests in natural depressions in rock or in shallow scrapes in soil, sand or vegetation (del Hoyo et al. 1996) that may be positioned on ledges or crevices of sheer cliffs, boulders at the base of cliffs, headlands, stacks, rocky islets, ridges, spits and peninsulas, rock fields by freshwater, and beaches of gravel, coarse shingle and sand (Higgins and Davies 1996).