Chilean skua
Chilean skua | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Stercorariidae |
Genus: | Stercorarius |
Species: | S. chilensis
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Binomial name | |
Stercorarius chilensis Bonaparte, 1857
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Synonyms | |
Catharacta chilensis |
The Chilean skua, also called the cinnamon skua (Stercorarius chilensis), is a large predatory
Chilean skuas feed on fish and other seabirds, as well as scraps, and carrion. They breed in colonies during the Southern Hemisphere summer.
Overall, little is known about this South American species and what is known largely comes from descriptive studies scattered through time and concentrated at a few select breeding colonies.
Taxonomy
The Chilean skua is part of
There are some reports of hybridization between the Chilean and Falkland skuas where their breeding ranges overlap.[5]
Description
Chilean skuas tend to be dark on their back, flanks, and cheeks, and uniformly light underneath. The dark colour usually extends from their back across the upper chest to form a pectoral collar. The underside of their wings is characteristically cinnamon-coloured, but this colour can be rather dull in some individuals. All adults have a distinctive dark cap and prominent pale gold streaking on the face and neck. They have black legs, brown irises, and a small, bluish bill with a dark tip.[5][6] Their wingspan is 130 to 138 cm.[7]
Juveniles tend to be brighter-colored than the adults, with no light streaking. They are also strongly capped but often lack the pectoral collar found in older birds.[5]
The Chilean skua could be confused with the Falkland skua, but it appears much more slender and compact in flight, with distinctive red coloration and white crescents on the wings.[5][6]
Habitat and distribution
The Chilean skua is endemic to South America, occupying coastal habitats from central Peru to northern Argentina. It nests between southern Chile and Cape Horn, Argentina, but its wintering range extends into Brazil, where it exploits the tropical coastal waters.[8][9] In 2009, one individual was exceptionally sighted on Inaccessible Island, which is part of the African region of the southern Atlantic.[6]
Breeding adults show a preference for sandy coastline with beached kelp and freshwater streams.[10] This species is also known for its association with southern hake fisheries in the fjords and channels of southern Chile.[11]
Behaviour
Vocalizations
Very little information is available on the vocalizations of the Chilean skua. At the breeding colony, it performs a long-call which consists of ten to twelve short nasal barks.[7] This call is seemingly unrelated to chick-rearing and has been described as almost goose-like due to its distinctly deep and hoarse nature.[6][10] Other calls may include short guttural grunts.[7]
Diet
The diet of the Chilean skua is not well described, but they appear to mainly be
Reproduction
From November to February or March,
There are usually two eggs in a clutch, and these are incubated for 28 to 32 days.[7]
In the absence of their parents, chicks will remain motionless at their nest site and camouflage themselves in the sand among patches of
Notes
External links
Furness, R. W., & Busby, J. (2010). The Skuas. Bloomsbury Publishing.
Olsen, K. M., & Larsson, H. (2013). Skuas and Jaegers: A guide to the Skuas and Jaegers of the world. Yale University Press.
Erize, F. & Rumboll, M. (2006). Birds of South America non passerines: Rheas to woodpeckers. Princeton University Press.
References
- ^ BirdLife International (2012). "Catharacta chilensis". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.
- ^ (n.d.). Stercorarius chilensis Bonaparte, 1857. Retrieved October 12, 2023, from Integrated Taxonomic Information System (ITIS) on-line database. https://www.1.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=660060#null
- ^ a b c d e f Devillers, P. (1978). Distribution and relationships of South American skuas. Gerfaut, 68, 374-417. https://sora.unm.edu/sites/default/files/4-1978.pdf
- ^ doi:10.5962/p.309920
- ^
- ^ Tavares, D. C., de Moura, J. F., Amorim, C. E., Boldrini, M. A., & Siciliano, S. (2012). Aves, Stercorariidae, Chilean kkua Stercorarius chilensis Bonaparte, 1857: First documented record for the state of Espírito Santo, southeastern Brazil. Check List, 8(3), 560-562. https://checklist.pensoft.net/lib/ajax_srv/article_elements_srv.php?action=download_pdf&item_id=18446
- ^ Silva, R., Olmos, F., & Lima, P. (2002). Catharacta chilensis (Bonaparte, 1857) no Brasil. Ararajuba, 10, 275-277. https://www.researchgate.net/publication/299515072_Catharacta_chilensis_Bonaparte_1857_no_Brasil
- ^ a b c d e Suezo, C., Arriagada Castro, A., Baessolo, L., Casas, M., & Salas, M. (2012). Notes on breeding biology and ecology of Chilean skua (Stercorarius chilensis) in sub-Antarctic archipelagos of western Patagonia. Ornitología Neotropical, 23, 235-242. https://www.researchgate.net/publication/262965025_Notes_on_breeding_biology_and_ecology_of_Chilean_Skua_Stercorarius_chilensis_in_sub-Antarctic_archipelagos_of_western_Patagonia
- .
- ^ a b c Reinhardt, K., Hahn, S., Peter, H.-U., & Wemhoff, H. (2000). A review of the diets of Southern Hemisphere skuas. Marine Ornithology, 28, 7-19. https://www.researchgate.net/publication/266140033_A_review_of_the_diets_of_Southern_Hemisphere_Skuas
- ^ Clark, G., Cowan, A., Harrison, P., & Bourne, W. (1992). Notes on the seabirds of the Cape Horn Islands. Notornis, 39, 133-144. https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=aef34b4309b947bff876e7c735f7e4d9b4219aad