Snow petrel

Snow petrels (Pagodroma nivea) are an all white, small fulmarine petrel with conspicious dark eyes, small black bill and bluish gray feet. There are two subspecies of snow petrel that differ only in size.

Snow petrel breed on South Georgia, the South Sandwich Islands, South Orkney Islands, Bouvet, the Balleny Islands, and Scott Island and at numerous localities on the Antarctic Peninsula and Antarctic Continent.

Snow petrel are almost entirely restricted to cold antarctic waters and are associated with pack ice, icebergs and ice floes. Flocks are characteristically seen sitting on icebergs.

Snow petrel nest colonially in small to large colonies on cliffs, usually near the sea, but also inland. Some birds remain at the colony all year, but the main influx of birds to the colonies is from mid-September until early November.

The nest is a simple pebble-lined scrape usually in a deep rock crevice with overhanging protection. One white egg is laid in late November to mid-December . The egg is incubated for 41-49 days and the chick is brooded for 8 days. The chick then remains in the nest for an additional 7 weeks. Snow petrel chicks leave the nest in late February to mid-May.

At sea, snow petrel eat mainly fish, some cephalopods (squid), other molluscs, and euphausiids. They also feed on seal placenta and the carcasses of dead seals, whales and penguins, and occasionally eat refuse on land. The Snow petrel do not normally follow vessels. 

Snow petrel tend to fly low over the water but very high over land to avoid predators such as South Polar skuas.

Skuas are major predators, but severe weather conditions, especially heavy snow that blocks nest entrances, may cause adults to abandon their eggs or chicks to starve. Egg mortality is approximately 50% while chick mortality is typically 10-15%.

Links

Taxonomic information on the Snow petrel

Australian Antarctic Science (AAS) projects relating to petrel

Australian Antarctic Magazine - Heard Island's seabirds under scrutiny

Monitoring for long-term or cumulative impacts in Southern Ocean seabirds

See more information on the Australian Antarctic scientific research program