Southern giant petrels are largely scavengers, and feed mainly on seal and penguin carcasses, offal, refuse from ships and discarded fish (2) (5). They often feed close to trawlers and vessels fishing with longlines (2). They also prey upon penguins and other birds, krill and amphipod crustaceans, fish and squid. During chick rearing, they depend heavily on penguins and seal colonies, as a food resource (5).
During the breeding season, loose colonies form at the breeding sites (2). During October or November, pairs lay a single large egg into a low cup-shaped nest made of grass, moss and gravel. The eggs are incubated for 55 to 66 days (6). The chick remains in the nest until it fledges towards the end of March. Giant petrels are very susceptible to disturbance during the breeding season, and tend to abandon the nest if they are threatened (4). Petrels are able to regurgitate foul-smelling oil which they spit at intruders; this habit earned the southern giant petrel the alternative name of ‘stinker’ (7).
After fledging, juvenile birds spend their first two or three years of life at sea on an extensive migration, in which they circumnavigate the Southern Ocean. Although this species may begin to breed at four years, most individuals begin to breed between six and ten years of age (5).