Southern giant petrel
Scientific name: Macronectes giganteus
Appearance: Southern giant petrels have two distinct colour phases, which are 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.
Wingspan: Approximately 1.8 to 2.1m
Mass: 3.8 to 5kg, females lighter
Length: Up to 1m
Breeding age: Age at first breeding between 4 and 8 years
Breeding frequency: Annual
Breeding season: Breeding birds arrive in September. Egg laying commences in late October, with eggs hatching in late December and chicks fledging in May
Longevity: Banded birds have lived for more than 30 years
What do I eat? 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 more on carrion.
What eats me? There are no known predators
Range trip time: Unknown for birds at Heard Island.
Range trip length: Foraging trips by breeding birds have been recorded up to around 15,000 km.
Distribution & abundance
Distribution: Breeds on the Antarctic continent, Antarctic Peninsula and on subantarctic islands including Heard Island, South Georgia, Marion, and Îles Crozet. During non-breeding season, can migrate and disperse great distances over the Southern Ocean. 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.
Abundance: There are approximately 3000 breeding pairs on Heard Island.
The species is a listed threatened (endangered), marine and migratory species under the Environment Protection and Biodiversity Conservation Act 1999 and is listed under international conservation agreements, including the:
- Agreement on the Conservation of Albatrosses and Petrels (ACAP)
- Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention) and,
- Agreement between the Government of Australia and the Government of Japan (JAMBA)
The species is also covered by a number of conservation plans, including the:
- National Recovery Plan for Albatrosses and Giant Petrels
- Threat Abatement Plan for the Incidental Catch (or By-catch) of Seabirds During Oceanic Longline Fishing Operations and,
- Action Plan for Australian Birds 2000
Southern 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.