Skua
Skuas | |
---|---|
Pomarine jaeger | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Suborder: | Lari |
Family: | Stercorariidae Gray, 1871 |
Genus: | Stercorarius Brisson, 1760 |
Type species | |
Larus parasiticus Linnaeus, 1758
| |
Species | |
See text. |
The skuas
The English word "skua" comes from the Faroese name for the great skua, skúgvur [ˈskɪkvʊɹ], with the island of Skúvoy renowned for its colony of that bird. The general Faroese term for skuas is kjógvi [ˈtʃɛkvɪ]. The word "jaeger" or Jäger is German for "hunter".[1][2] The genus name Stercorarius is Latin and means "of dung";[note 1] the food disgorged by other birds when pursued by skuas was once thought to be excrement.[3]
Skuas nest on the ground in
Biology and habits
Outside the breeding season, skuas take fish, offal, and carrion. Many practice kleptoparasitism, which comprises up to 95% of the feeding methods of wintering skuas, by chasing gulls, terns and other seabirds to steal their catches, regardless of the size of the species attacked (up to three times heavier than the attacking skua). The larger species, such as the great skua, also regularly kill and eat adult birds, such as puffins and gulls, and have been seen killing birds as large as a grey heron.[5] On the breeding grounds, the three, more slender northern breeding species commonly eat lemmings. Those species that breed in the southern oceans largely feed on fish that can be caught near their colonies. The eggs and chicks of other seabirds, primarily penguins, are an important food source for most skua species during the nesting season.[6]
In the southern oceans and Antarctica region, some skua species (especially the south polar skua) will readily scavenge carcasses at breeding colonies of both penguins and pinnipeds. Skuas will also kill live penguin chicks. In these areas, the skuas will often forfeit their catches to the considerably larger and very aggressive giant petrels. Skuas have also been observed to directly pilfer milk from the elephant seal's teat.[7]
They are medium to large
The skuas are strong, acrobatic fliers. They are generally aggressive in disposition. Potential predators approaching their nests will be quickly attacked by the parent birds, which usually target the heads of intruders – a practice known as 'divebombing'.[8]
Taxonomy
The genus Stercorarius was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the parasitic jaeger (Stercorarius parasiticus) as the type species.[9][10]
Skuas are related to
Species
The genus contains seven species:[13]
Common name | Scientific name and subspecies | Range | Size and ecology | IUCN status and estimated population |
---|---|---|---|---|
Chilean skua | Stercorarius chilensis Bonaparte, 1857 |
Breeds along the coasts of southern Chile and southern Argentina, winters along the Pacific coasts of Peru and Chile as well as the Atlantic coast of Argentina |
Size: Habitat: Diet: |
LC
|
South polar skua | Stercorarius maccormicki Saunders, 1893 |
Breeds along the coast on Antarctica, winters in the north Atlantic and north Pacific |
Size: Habitat: Diet: |
LC
|
Brown skua | Stercorarius antarcticus (Lesson, 1831) |
Southern Ocean |
Size: Habitat: Diet: |
LC
|
Great skua | Stercorarius skua (Brünnich, 1764) |
Breeds along the coastline of the northeast Atlantic, winters in the north Atlantic |
Size: Habitat: Diet: |
LC
|
Pomarine jaeger or pomarine skua | Stercorarius pomarinus (Temminck, 1815) |
Breeds along the Arctic coastline, winters in tropical and subtropical oceans |
Size: Habitat: Diet: |
LC
|
Parasitic jaeger or Arctic skua | Stercorarius parasiticus (Linnaeus, 1758) |
Breeds along the Arctic coastline, winters in the southern hemisphere |
Size: Habitat: Diet: |
LC
|
Long-tailed jaeger or long-tailed skua | Stercorarius longicaudus Vieillot, 1819 Two subspecies
|
Breeds in the Arctic, winters in the Southern Ocean |
Size: Habitat: Diet: |
LC
|
References
- , etc.
- ^ "Jaeger". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ^ "Skua". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ISBN 978-1-4081-2501-4.
- ^ Mark Sabbatini, "Non-human life form seen at Pole", The Antarctic Sun, 5 January 2003.
- ^ Scottish Ornithologists' Club Archived 2011-07-16 at the Wayback Machine
- ^ ISBN 1-85391-186-0.
- ^ "Antarctica's Milk-Stealing, Grudge-Holding Seabirds". Boston NPR. 2016.
- ^ "Scottish Wildlife Trust builds £50,000 loo on Handa". BBC News. 12 March 2012.
- ^ Brisson, Mathurin Jacques (1760). Ornithologie, ou, Méthode Contenant la Division des Oiseaux en Ordres, Sections, Genres, Especes & leurs Variétés (in French and Latin). Paris: Jean-Baptiste Bauche. Vol. 1, p. 56, Vol. 6, p. 149.
- ^ Peters, James Lee, ed. (1934). Check-list of Birds of the World. Vol. 2. Cambridge, Massachusetts: Harvard University Press. p. 311.
- ^ American Ornithologists' Union (2000). Forty-second supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 117(3):847–858.
- ^ Cohen, Baker, Belchschmidt, Dittmann, Furness, Gerwin, Helbig, de Korte, Marshall, Palma, Peter, Ramli, Siebold, Willcox, Wilson and Zink (1997). Enigmatic phylogeny of skuas. Proc. Biol. Sci. 264(1379):181–190.
- ^ Gill, Frank; Donsker, David, eds. (2019). "Noddies, gulls, terns, auks". World Bird List Version 9.2. International Ornithologists' Union. Retrieved 24 June 2019.
External links
- Encyclopædia Britannica. Vol. 25 (11th ed.). 1911. .
- Great Skua videos on the Internet Bird Collection