Snow petrel (Pagodroma nivea)

Description

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Snow petrel fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Snow petrel description

One of few birds that breed exclusively in the Antarctic, this bird is strongly associated with snow throughout its life, a feature alluded to by its beautiful, all-white, cryptic plumage and name, nivea, which means ‘snowy’ in Latin ^{(2) (3) (4)}. An unmistakable species, the snow petrel has a very small, black bill, dark, conspicuous eyes and lead-grey feet ⁽⁵⁾. The adults are much alike, although the female is typically slightly smaller, but the juvenile is distinguished by extensive black barring on its upperparts ^{(2) (5)}. This medium-sized petrel has long wings and a tail that is nearly square when folded, but appears fan-shaped in flight ⁽⁵⁾. The snow petrel is an extremely agile seabird that flies low over the water, using more rapid wingbeats and less gliding compared to other petrels, but may fly higher over land to avoid detection by predators ^{(3) (4) (5) (6)}. Another characteristic feature of the snow petrel is the great variability in size amongst individuals, with the largest birds around one and a half times bigger than the smallest ⁽³⁾.

There is some debate over the taxonomy of the snow petrel. Limited evidence suggests that populations breeding north of the pack ice may actually be a separate species. But in the absence of further evidence, this debate is currently unresolved ⁽⁷⁾.

Size

Length: 30 – 40 cm ⁽²⁾

Wingspan: 75 – 95 cm ⁽²⁾

Weight

240 – 460 g ⁽²⁾

Snow petrel biology

While solitary for much of the year, from late October to early November the snow petrel returns to breeding colonies to mate ^{(3) (6)}. Upon returning to the colony, the male snow petrel performs an unusual aerial display to attract its mate and the pair will subsequently descend to the nest and touch bills, reinforcing the pair bond ^{(3) (9)}. The nest is no more than a  simple pebble-lined scrape in a sheltered hollow or rocky crevice, with overhanging cover offering protection from the extreme elements ^{(2) (4)}. Competition for nesting sites is fierce and the birds are strongly territorial and aggressively repel intruders by grasping bills, screeching, flapping wings and spitting their waxy, yellowish stomach oil ^{(3) (4)}. A single large, white egg is laid and incubated for 41 to 49 days. After hatching the chicks are intensively cared for by the parents for around eight days, as at this time they are particularly vulnerable to attacks from predators, such as skuas. The young birds fledge from the nest after some 41 to 45 days, usually from late February to mid-May, and may live to reach 20 years of age ^{(2) (4)}.

The snow petrel feeds mainly on fish, krill, squid and carrion, such as seal, whale and bird carcasses. While foraging at sea, it typically seizes prey in its bill near the water’s surface, although it may also dive for its food ⁽²⁾.

Snow petrel range

Along with the South polar skua (Catharacta maccormicki), the snow petrel breeds further south than any other bird and has even been seen at the South Pole ⁽⁴⁾. It breeds primarily on the Antarctic continent and peri-Antarctic islands, as well as some islands lying north of the pack ice, including South Georgia, Bouvetøya, the South Sandwich Islands and South Orkney Islands, where it nests in colonies on cliffs ^{(3) (6)}. It is strongly associated with the cold Antarctic waters, rarely straying far from pack ice, and regularly rests on icebergs while at sea ^{(3) (5) (8)}.

Snow petrel habitat

Restricted to Antarctic waters, the snow petrel is most commonly found in areas with pack ice and icebergs. It breeds on cliffs and rock faces up to 440 kilometres inland and 2,400 metres above sea level ^{(2) (3)}.

Snow petrel status

Classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾.

Snow petrel threats

The snow petrel is one of the most abundant birds in the Antarctic region with a population possibly numbering as high as several million birds ^{(2) (3) (10)}.  As this bird inhabits inhospitable, remote areas, it has avoided human persecution and lacking any significant threats to its survival, its population may even be increasing ⁽²⁾. Climate change could, however, threaten this species in the future as Antarctic birds appear to be breeding later in response to a reduction in the extent of sea ice cover, causing decreases in prey species in some areas, or the increasing length of the sea ice season delaying access to breeding grounds ⁽¹¹⁾.

Snow petrel conservation

In the absence of any significant threats to its survival, the snow petrel has not been the target of any specific conservation measures. However, it has benefited from some conservation projects undertaken within its range, such as efforts to remove invasive predators from South Georgia and conserve natural habitats on the South Sandwich Islands ^{(12) (13)}.

ARKive is supported by OTEP, a joint programme of funding from the UK FCO and DFID which provides support to address priority environmental issues in the Overseas Territories, and Defra

Find out more

For more information on the snow petrel, see:

• The Polar Conservation Organisation:
  http://www.polarconservation.org/education/antarctic-animals/antarctic-birds/snowpetrel

To find out more about conservation on South Georgia, see:

• The South Georgia Heritage Trust:
  http://www.sght.org/
• Procter, D. and Fleming, L.V (1999) Biodiversity: the UK Overseas Territories. Joint Nature Conservation Committee, Peterborough, UK. Available at:
  http://www.jncc.gov.uk/page-3045%23download

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org

Authentication

Authenticated (22/09/2010) by Ross Wanless, Honorary Research Associate, Percy FritzPatrick Institute of African Ornithology, University of Cape Town, South Africa.
http://www.fitzpatrick.uct.ac.za/docs/ross.html

Glossary

Carrion

The flesh of a dead animal.

Cryptic colouration

Colouration that makes animals difficult to detect against their background. The colouration may provide camouflage against a background or break up the outline of the body.

Incubate

To keep eggs warm so that development is possible.

Pack ice

Sea ice that floats on the surface of the water. Often formed from large pieces of ice that consolidate into a single ice mass, pack ice typically moves with currents, tides and wind.

Taxonomy

The science of classifying organisms, grouping together animals which share common features and are thought to have a common ancestor.

Territorial

Describes an animal, a pair of animals or a colony that occupies and defends an area.

References

1. IUCN Red List (July, 2010)
   http://www.iucnredlist.org/
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
3. Brooke, M. (2004) Albatrosses and Petrels across the World. Oxford University Press, Oxford.
4. The Polar Conservation Organisation (July, 2010)
   http://www.polarconservation.org/education/antarctic-animals/antarctic-birds/snowpetrel
5. Harper, P.C. and Kinsky, F.C. (1978) Southern Albatrosses and Petrels. Victoria University Press, Wellington.
6. Australian Antarctic Division (July, 2010)
   http://www.aad.gov.au/default.asp?casid=1609
7. Wanless, R. (2010) Pers. comm.
8. BirdLife International (July, 2010)
   http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=3876&m=0
9. Perrins, C. (2009) The Encyclopedia of Birds. Oxford University Press, Oxford.
10. Croxall, J.P., Steele, W.K., McInnes, S.J. and Prince, P.A. (1995) Breeding distribution of the snow petrel Pagodroma nivea. Marine Ornithology, 23: 69-99.
11. Barbraud, C. and Weimerskirch, H. (2006) Antarctic birds breed later in response to climate change. Proceedings of the National Academy of Sciences USA, 103: 6248-6315.
12. The South Georgia Heritage Trust (July, 2010)
    http://www.sght.org/
13. Procter, D. and Fleming, L.V (1999) Biodiversity: the UK Overseas Territories. Joint Nature Conservation Committee, Peterborough, UK. Available at:
    http://www.jncc.gov.uk/page-3045%23download