Southern giant petrel
Scientific name: Macronectes giganteus
Southern giant petrels have two distinct colour phases, white and dark.
Dark phase adults have a grey-brown body with white head, neck and brown speckled breast. Juveniles of dark phase birds have a dark brown body with a dark brown iris, which closely resemble northern giant petrel juveniles.
White phase birds are completely white except for a few scattered dark feathers. White phase birds generally constitute a maximum of 5% of a population.
Distribution and abundance
Southern giant petrels breed on the Antarctic continent, Antarctic Peninsula and on subantarctic islands including Heard Island, South Georgia, Marion, and Iles Crozet.
Southern giant petrels nest in ice-free coastal areas, rocky bluffs, open flats, edges of plateaux or offshore rocks. However, even though nests may be totally covered by snow, the parental birds often continue to sit on them to protect their eggs or chicks from the potentially fatal cold.
Conservation status: least concern but with populations decreasing
Both southern and northern giant petrels tend to return to the same nesting sites every breeding season. Some pairs have been observed returning to the same nest year after year.
Southern giant petrels will defend their eggs and small chicks.
Diet and feeding
Both southern and northern giant petrels feed on krill, squid, fish, other small seabirds, and carcasses of marine mammals. However, it has been shown that there is a significant dietary difference between the sexes. Females feed more on live prey at sea such as krill, squid, and fish, whereas males feed tend more toward carrion.
Both adult birds and chicks can regurgitate foods and oils to a distance of a metre or more if they are disturbed.