Southern giant petrel (Macronectes giganteus) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Southern Giant Petrel Macronectes giganteus (Gmelin 1789), as an ENDANGERED SPECIES on Part 1 of Schedule 1 of the Act. Listing of Endangered Species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee found that:

1. The Southern Giant Petrel Macronectes giganteus, is a large seabird of length 85-100cm and wingspan 150-210cm. The species is sexually dimorphic, with males larger than females. Within populations, two colour morphs occur: the most common is the dark morph with a white head and neck, and a dark grey-brown body; and a white morph with scattered black feathers. The species is listed as Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.

2. The Southern Giant Petrel has a circumpolar pelagic range from Antarctica to approximately 20° S and is a common visitor off the entire length of the New South Wales coast (H. Battam, pers. comm.; Blakers et al. 1984). Over summer, the species nests in small colonies amongst open vegetation on Antarctic and subantarctic islands, including Macquarie and Heard Islands and in Australian Antarctic territory. A single chick is raised and although breeding occurs annually, approximately 30% of the potential breeding population does not nest (Voisin 1988).

3. The Southern Giant Petrel is an opportunistic scavenger and predator. The species regularly attends fishing vessels and scavenges animal carcasses on land. Southern Giant Petrels are also an active predator of cephalopods and euphausiids, as well as smaller birds (particularly penguins) both at land and at sea. Although representing a small proportion of its total foraging area, potential forage in NSW waters during the winter is nonetheless considered significant for the species.

4. The current global population of Southern Giant Petrels was recently estimated to be 31,358 breeding pairs (Patterson et al., in press). This estimate represents a population reduction of approximately 17% from a previous estimate of 38 000 pairs (Hunter 1985). Further, the estimated 5,000 breeding pairs in Australian territory represents a reduction of approximately 50% since the middle of the last century (Marchant and Higgins 1990).

5. A significant threat to Southern Giant Petrels is mortality via longline fishing. 'Incidental catch (or bycatch) of seabirds during oceanic longline fishing operations' is a Commonwealth listed Key Threatening Process under the Environment Protection and Biodiversity Conservation Act 1999. Among other pelagic bird species, the listing identifies Southern Giant Petrels to be adversely affected by longline fishing.

6. On their breeding islands, Southern Giant Petrels are threatened by predation from Feral Cats and Black Rats, and by habitat degradation from introduced Caribou, Sheep and Rabbits. On some breeding islands, e.g. on the Falkland Islands, hunting has caused substantial decreases or local extinctions, (Elliot 1957; Williams 1984).

7. Within NSW waters, potential threats are the loss of the southern cuttlefish populations, illegal longline fishing and oil spills.

8. Environmental changes potentially exacerbate the impact of threats to the Southern Giant Petrel. A recent southerly shift in the Antarctic Polar Frontal Zone has resulted in increased sea and air temperatures and may have altered upwelling patterns and hence marine prey availability (Patterson et al., in press.).

9. In view of the above points, the Scientific Committee is of the opinion that the Southern Giant Petrel Macronectes giganteus, is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival or evolutionary development cease to operate.

Proposed Gazettal date: 05/10/01
Exhibition period: 05/10/01 - 0911/01

References:

Blakers, M., Davies, S.J.J.F. and Reilly, P.N. (1984). 'The Atlas of Australian Birds'. Melbourne University Press: Melbourne.

Elliot, H.F.I. (1957). A contribution to the ornithology of the Tristan da Cunha group. Ibis 99, 545-586.

Hunter, S. (1985). The role of the Giant Petrels in the Southern Ocean ecosystem. In 'Antarctic Nutrient Cycles and Food Webs'. (Eds W.R. Siegfried, P.R. Condy and R.M. Laws.) pp. 534-542. Springer-Verlag: Berlin.

Marchant, S. and Higgins, P.J. (1990). 'Handbook of Australian, New Zealand and Antarctic Birds'. Vol.1. Oxford University Press: Melbourne.

Patterson, D.L., Woehler, E.J., Croxall, J.P., Poncet, S. and Fraser, W.R. (in press). Breeding distribution and population status of the Northern Giant Petrel (Macronectes halli) and the Southern Giant Petrel (M. giganteus). Marine Ornithology.

Voisin, J.-F. (1988). Breeding biology of the Northern Giant Petrel Macronectes halli and the Southern Giant Petrel M. giganteus at Ile de la Possession, Iles Crozet, 1966-1980. Cormorant 16, 65-97.

Williams, A.J. (1984).The status and conservation of seabirds on some islands in the African sector of the Southern Ocean. In 'Status and Conservation of the World's Seabirds'. (Eds J.P. Croxall, P.G.H. Evans and R.W. Schrieber.) pp. 627-634. International Council for Bird Conservation: Cambridge.