|Scientific Name:||Sterna elegans|
|Species Authority:||Gambel, 1849|
|Taxonomic Notes:||The BirdLife Taxonomic Working Group is aware that phylogenetic analyses have been published which have proposed generic rearrangements which may affect this species, but prefers to wait until work by other taxonomists reveals how these changes affect the entire groups involved.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Keitt, B., Tershy, B. & Verlarde, E.|
This species is considered Near Threatened as it has a restricted breeding range, with more than 90% of the breeding population being restricted to a single island. It is also subject to large population fluctuations in response to climatic effects, and could be negatively affected by climate change, human intrusions and overfishing.
|Range Description:||Sterna elegans breeds along the Pacific coast from south California, USA, to Baja California and the Gulf of California, Mexico (Howell and Webb 1995a, AOU 1998). The estimated population is 51,000-90,000 individuals (J. A. Kushlan et al. 2002) with up to 95% breeding on Isla Rasa in the Gulf of California (Velarde and Anderson 1994). At least three other Mexican islands are used at least occasionally (Velarde and Anderson 1994). In addition, small populations breed on Bolsa Chica (50-4,000 pairs, first recorded in 1987) and in San Diego bay (500-800 pairs), California (Velarde and Anderson 1994, Gochfeld and Burger 1996, E. Verlarde in litt. 1998, B. Tershy and B. Keitt in litt. 1999). Non-breeding birds summer from California to Costa Rica (AOU 1998). Birds winter from Guatemala to El Salvador, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, Peru and Chile (AOU 1998). There are significant population fluctuations, probably caused by the effects of El Niño Southern Oscillation (compounded by over-fishing) on prey abundance and consequently breeding success (E. Verlarde in litt. 1998, B. Tershy and B. Keitt in litt. 1999). Only the Isla Rasa colony breeds every year (B. Tershy and B. Keitt in litt. 1999), but fluctuations are considerably less than one order of magnitude.|
Native:Chile; Colombia; Costa Rica; Ecuador; El Salvador; Mexico; Nicaragua; Panama; Peru; United States
Vagrant:Belgium; Denmark; Falkland Islands (Malvinas); France; Ireland; United States Minor Outlying Islands
Present - origin uncertain:Guatemala; Honduras
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Kushlan et al. (2002).|
|Habitat and Ecology:||This species breeds on flat rocky areas and is strongly tied to the coast. It forages in inshore waters, estuarine habitats, salt ponds and lagoons, with some individuals venturing further offshore in the non-breeding season.|
|Major Threat(s):||Population fluctuations may be related to El Niño Southern Oscillation events, but food supply may also be influenced by over-fishing. Nest robbery formerly reduced colony size on Isla Rasa, but this site now receives adequate protection.|
Conservation Actions Underway
Conservation Actions Proposed
Monitor population trends throughout the breeding range. Research links between climate, fisheries, prey availability and breeding success. Ensure continued effective protection of all breeding colonies.
Anderson, D. W. 1976. The Gulf of California, Mexico. Canadian Field-Naturalist 90: 270-271.
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Gochfeld, M.; Burger, J. 1996. Sternidae (Terns). In: del Hoyo, J.; Elliott, A.; Sargatal, J. (ed.), Handbook of the birds of the world, pp. 624-667. Lynx Edicions, Barcelona, Spain.
Howell, S. N. G.; Webb, S. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, Oxford.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Kushlan, J. A.; Steinkamp, M. J.; Parsons, K. C.; Capp, J.; Cruz, M. A.; Coulter, M.; Davidson, I.; Dickson, L.; Edelson, N.; Ellio, R.; Erwin, M.; Hatch, S.; Kress, S.; Milko, R.; Miller, S.; Mills, K.;…authors continued in notes. 2002. Waterbird conservation for the Americas. U.S. Fish & Wildlife Service National Publications Clearinghouse, Shepherdstown, U.S.A.
Sowls, A. L.; DeGange, A. R.; Nelson, J. W.; Lester, G. S. 1980. Catalogue of California seabird colonies. US Fish and Wildlife Service, US Department of the Interior, Washington, D.C.
Velarde, E.; Anderson, D. W. 1994. Conservation and management of seabird islands in the Gulf of California: setbacks and successes. In: Nettleship, D.N.; Burger, J.; Gochfeld, M. (ed.), Seabirds on islands: threats, case studies and action plans, pp. 229-243. BirdLife International, Cambridge, UK.
|Citation:||BirdLife International 2012. Sterna elegans. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 23 May 2013.|
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