







| Kingdom | Phylum | Class | Order | Family |
|---|---|---|---|---|
| ANIMALIA | CHORDATA | AVES | CHARADRIIFORMES | LARIDAE |
| Scientific Name: | Larus audouinii | ||||||
| Species Authority: | Payraudeau, 1826 | ||||||
Common Name/s:
|
|||||||
| Red List Category & Criteria: | Near Threatened ver 3.1 | |||||||||
| Year Published: | 2010 | |||||||||
| Assessor/s: | BirdLife International | |||||||||
| Reviewer/s: | Calvert, R., Butchart, S., Bird, J. | |||||||||
| Contributor/s: | Oro, D., Eken, G., Omnus, O., Arcos, J., Papaconstantinou, C., Carboneras, C. | |||||||||
|
Justification: This species may undergo a moderately rapid population decline in future if current fishery practices change and as such it is precautionarily treated as Near Threatened. |
||||||||||
| History: |
|
|||||||||
| Range Description: | Larus audouinii breeds in (all data for pairs) Spain (20,3154), mainly the Chafarinas Islands and the Ebro Delta with the latter holding 65% of the global population9, Algeria (100-600), Greece (700-9003 in 65 colonies), and the Sardinia and Tuscan Archipelago, Italy (550-650), with smaller colonies in Portugal (40), Corsica, France (between 54-605 and 807), Cyprus (c. 3240), islets and rocks in the southern Adriatic Sea near Korcula and Peljesac Peninsula, Croatia (658 in 5 colonies), Turkey (60-902), Tunisia (70-115) and Morocco (50-300). It winters on the coast of North and West Africa from Libya west to Morocco and south to Mauritania, Gambia, Senegal and Gabon13 and there is a small wintering population in the east Mediterranean along the Aegean coast of Turkey. The global population has been estimated at c.21,500 pairs, and a recent assessment put the European population (including some Spanish islands and islets off Morocco) at 20,500-21,000 pairs (encompassing over 90% of the global population) and stable or increasing throughout. This represents a significant increase from an estimated population of 1,000 pairs in 1975 and is thought to be a result of the increased availability mainly of effectively protected areas during the 1980s, and secondly of discarded fish from the trawlers, particularly around the Ebro Delta1. The large expansion of Larus audouinii in the western Mediterranean has probably caused the breeding population in other parts of the Mediterranean to increase and new colonies have been found in Croatia and even out of the Mediterranean in southern Portugal10,12. Nevertheless more than 90% of the European breeding population occurs at just four sites and only a single site (the Ebro Delta) held 70% of the global breeding numbers in 2006. Recruitment can be extremely rapid when food availability is high, resulting in high population growth rates15,26. It is a long-lived species with high adult survival and relatively low fertility. Adult annual survival is estimated at 0.9515,19,25. |
| Countries: |
Native:
Algeria; Croatia; Cyprus; France; Gambia; Gibraltar; Greece; Italy; Libyan Arab Jamahiriya; Mauritania; Morocco; Portugal; Senegal; Spain; Tunisia; Turkey
Vagrant:
Bulgaria; Czech Republic; Egypt; Georgia; Germany; Israel; Jordan; Lebanon; Macedonia, the former Yugoslav Republic of; Malta; Palestinian Territory, Occupied; Switzerland; United Kingdom
Present - origin uncertain:
Albania; Bosnia and Herzegovina; Monaco; Montenegro; Slovenia; Syrian Arab Republic; Western Sahara
|
| Range Map: | Click here to open the map viewer and explore range. |
| Population: | The global population (excluding Europe) is estimated to be 19,200 pairs (Lambertini 1996), with 18,000-19,000 pairs in Europe (BirdLife International 2004), giving a total of 57,600 individuals. |
| Population Trend: |
Decreasing
|
| Habitat and Ecology: | Behaviour Audouin's Gull is a medium sized gull largely restricted to the Mediterranean. It is partially migratory and dispersive30. It breeds in large monospecific colonies ranging from 10 up to 10,000 pairs30 at a density of up to 1 nest/ sq. m30 . Egg-laying takes place in the second half of April until the beginning of May, and peak hatching occurs in late May30, with fledging mainly in the first two weeks of July. It has a large foraging range while breeding, and has been recorded up to 200 km from the colony27. After breeding the birds disperse widely around the Mediterranean coast13,30. Almost all juveniles and some adults migrate past Gibraltar during July-October31, to winter on the North African coast30. During the winter it roosts in flocks of several thousand31. It returns to its breeding sites between late February and mid April30. First year birds remain in the non-breeding range throughout the summer32. Very high colony-site fidelity is probably related to previous breeding success. However, in the Aegean Islands, birds return to the same "island group" but not necessarily to the same islet. At the Ebro Delta, Spain, c.1,400 breeders disperse to other colonies every year, generating marked fluctuations at those sites15. The Audouin's Gull is one of the few species of Larid to show nocturnal foraging patterns, which may be linked to fisheries activities; arrivals and departures from the Ebro Delta colony are in accordance with the trawling timetable27. The species scavenges around fishing vessels, and uses discards extensively and very efficiently27. The species's association with fisheries is more pronounced in the western than in the central and eastern Mediterranean34. A trawler moratorium off the Ebro Delta has caused decreased food availability to birds and has also negatively affected breeding success, possibly by necessitating increased foraging ranges36. Habitat Breeding Colonies are located on exposed rocky cliffs and on offshore islands or islets32, normally not more than 50 m above sea level32. The Ebro delta colony is located on saltmarsh and a sandy peninsula31. In the Aegean it breeds on uninhabited islands sloping gently to the sea and covered with large stones, eryngo Eryngium, grass and low bushes of Pistacia lentiscus32. Characteristics of habitats used differ from region to region and even within the same areas in different years: altitude ranges from close to sea-level to 100 m, vegetation cover from bare rocks to 85% bush cover, and slope from 0-90o. Medium vegetation cover is preferred, and this probably provides chicks with shelter from heat and predators. The concentration of breeding colonies in the western Mediterranean is possibly related to the lower water salinity and higher abundance of clupeids. Non-breeding During the non-breeding season the species prefers sheltered bays, either flat and shingly, sandy or with cliffed margins32. It sometimes visits seaside resorts and marinas lured by food, and it especially likes areas on beaches where freshwater occurs, such as stream mouths or floods32. It is a coastal species, rarely occurring inland and generally not travelling far offshore32. Diet This species was historically thought to feed far out to sea, but more recent observations show that it feeds regularly along the coast. The diet consists mostly of epipelagic fish, especially Clupeiformes, for which it sometimes forages at night, taking advantage of its prey's diel migration patterns27 and of commercial fishing by purse-seine netting34. It is also known to take some aquatic and terrestrial invertebrates, small birds and plant material such as the peanut Arachis, olive Olea, and grain32. The Ebro delta colony feeds largely on fish waste dumped by boats fishing nearby33. The species is also known to feed on food discarded at tourist beaches32, and during a moratorium on trawling, it was found to forage in marshes, rice fields and occasionally at refuse tips27,30. Diet during the breeding season has been found to vary between colonies due to fishing practices that target different species in the respective areas34. Breeding site The nests is a shallow scrape lined with available debris and vegetation32. It is placed among rocks and vegetation30. Foraging range During the non-breeding season, surveys in Morocco found birds no further than 46 km from the coast37, and generally <40 km from the colony seems to be the norm27. However, the maximum recorded foraging range from a colony was 160 km27. The species primarily forages in coastal and continental shelf areas between 5 and 15 nautical miles (nm) offshore. A radius of 15 nm from the Ebro Delta would ensure the protection of 30% of the birds (or 30% of the foraging area). A 30 nm radius would protect 80% of birds. These distances could be reduced in colonies where the surrounding continental shelf is narrower38. Juveniles tend to forage in upwelling zones, whereas subadults and adults are more independent of these sites39. |
| Systems: | Terrestrial; Marine |
| Major Threat(s): | The trawling fishery off the Ebro Delta is regarded as unsustainable and its collapse would probably result in a decline in the breeding population due to the increase in density-dependence15,25. A similar outcome would arise if waste from the trawlers were used industrially to produce food for domestic animals, as occurs in other areas, rather than being dumped near the Ebro colony.More important could be the reduction of small-pelagic fish stocks, the main natural prey for Audouin's Gull, due to increasingly high fishing pressure around the breeding grounds, owing partly to high demand by tuna-farming28. Other important threats include coastal tourism developments, regulation of the river Ebro, mortality due to entanglement in fishing gear (mainly longlines and sporting lines)17,18, and predation by terrestrial predators, such as red fox Vulpes vulpes, badger Meles meles and domestic dogs15,19. Predation by sympatric Yellow-legged Gull L. michahellis can be high at some breeding colonies, especially when densities of Audouin's Gulls are low6,11,16. Predation on chicks by black rats Rattus rattus has a negative impact at some breeding colonies35. Nevertheless Audouin's Gull shows a very nomadic breeding site selection and high dispersal rates from year to year, probably avoiding large densities of Yellow-legged Gulls20,21,22. Peregrines Falco peregrinus, other raptors, some herons and snakes can also prey on adults and nests but only accidentally and locally23,24. Very high levels of mercury and other pollutants are found in this species13, partly due to the consumption of discards 29, thus posing a potential threat, although no negative effects have been demonstrated. Current marine wind-farm projects, particularly around the main breeding colony (Ebro Delta), could also represent a serious threat. Overgrazing of some islets by goats in the east of its breeding range may reduce breeding success. Natal and breeding dispersal are extremely high ensuring genetic mixing and buffering against bad local environmental conditions through emigration and colonisation9,25. |
| Conservation Actions: |
Conservation Actions Underway CMS Appendix I and II. A European action plan was published in 1996. The ecology of this species, particularly its breeding and foraging behaviour and demography and population dynamics, has been extensively studied. Lebanon prepared an action plan to restore the breeding population back to Palm Islands Nature reserve. Several LIFE Nature projects have been implemented between 1992 and 2006 in Spain and Italy, contributing to successful recolonisation of breeding islands and development of safe line-fishing techniques. Control of invasive black rats Rattus rattus has been effective at some colonies35. Conservation Actions Proposed Continue to monitor breeding colonies. Identify appropriate actions to mitigate against the key threats. Implement strict fishery management policies in the species's range. Increase the area of suitable coastal habitat that is protected from development and degradation. Enforce laws designed to minimise marine pollution. Implement measures to reduce mortality in fishing gear, perhaps facilitated by legislation. Ensure regulation of the river Ebro benefits the species. |
|
Arcos, J.M. and Oro, D. 1996. Changes in foraging range of Audouin's gulls Larus audouinii in relation to a trawler moratorium in the western Mediterranean. Colonial Waterbirds 19: 128-131. Arcos, J. M.; Louzao, M.; Oro, D. 2008. Fishery ccosystem impacts and management in the Mediterranean: seabirds point of view. In: Nielsen, J.; Dodson, J.; Friedland, K.; Hamon, T.; Hughes, N.; Musick, J.; Verspoor, E. (ed.), Proceedings of the Fourth World Fisheries Congress: Reconciling Fisheries with Conservation, pp. 587-596. American Fisheries Society, Symposium 49, Bethesda, MD, USA. Arcos, J. M.; Ruiz, X.; Bearhop, S.; Furness, R. W. 2002. Mercury levels in seabirds and their fish prey at the Ebro Delta (NW Mediterranean): the role of trawler discards as a source of contamination. Marine Ecology Progress Series 232: 281-290. Belda, E. J.; Sanchez, A. 2001. Seabird mortality on longline fisheries in the western mediterranean: factors affecting bycatch and proposed mitigating measures. Biological Conservation 98: 357-363. BirdLife International. 2004. Birds in Europe: population estimates, trends and conservation status. BirdLife International, Cambridge, U.K. Bonaccorsi, G. 2003. Le Goéland D'audouin Larus audouinii dans le Golfe D'ajaccio: approche éthologique et écologique de 1980 à 2002. Alauda 71: 84-87. Charalambidou, I.; Gücel, S. 2008. First survey of Audouin's Gull, Larus audouinii (Payraudeau, 1826), colonies at Kleidhes Islands, Cyprus. Zoology in the Middle East 45: 29-34. Cooper, J.; Baccetti, N.; Belda, E. J.; Borg, J. J.; Oro, D.; Papaconstantinou, C.; Sánchez, A. 2003. Seabird mortality from longline fishing in the Mediterranean Sea and Macaronesian waters: a review and a way forward. Scientia Marina 67: 57-64. Cramp, S.; Simmons, K. E. L. 1983. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic vol. III: waders to gulls. Oxford University Press, Oxford. Criado, J. Ed. 1997. Revision of the International Action Plan for the Audouin's Gull Larus audouinii. del Hoyo, J.; Elliott, A.; Sargatal, J. 1996. Handbook of the Birds of the World, vol. 3: Hoatzin to Auks. Lynx Edicions, Barcelona, Spain. Genovart, M.; Oro, D.; Bonhomme, F. 2003. Genetic and morphological differentiation between the two largest breeding colonies of Audouin's Gull Larus audouinii. Ibis 145: 448-456. Hoogendoorm, W. and Mackrill, E.J. 1987. Audouin's gull in southwestern Palearctic. Dutch Birding 9(4): 99-107. Jones, H.P., Tershy, B.R., Zavaleta, E.S., Croll, D.A., Keitt, B.S., Finkelstein, M.E. and Howald, G.R. 2008. Severity of the effects of invasive rats on seabirds: a global review. Conservation Biology 22(1): 16-26. Lambertini, M. 1996. International action plan for Audouin's Gull (Larus audouinii). In: Heredia, B.; Rose, L.; Painter, M. (ed.), Globally threatened birds in Europe: action plans, pp. 289-301. Council of Europe and BirdLife International, Strasbourg. Mañosa, S.; Oro, D.; Ruiz, X. 2004. Activity patterns and foraging behaviour of Audouin’s gulls at the Ebro Delta, NW Mediterranean. Scientia Marina 68: 605-614. Martínez-Abraín, A., Oro, D., Forero, M. G. & Conesa, D. 2003. Modeling temporal and spatial colony-site dynamics in a long-lived seabird. Population Ecology 45: 133-139. Olsen, K. M.; Larsson, H. 2004. Gulls of Europe, Asia and North America. Christopher Helm, London. Onmus, O. 2006. Current status of the Audouin´s gull Larus audouinii Eastern Population. Oro, D. 1996. Are migrating peregrine Falcons Falco peregrinus a threat to breeding Audouin's Gull Larus audouinii at the Ebro Delta? Colonial Waterbirds 19: 270-272. Oro, D. 1997. Montpellier Snakes Malpolon monspessulanus as predators of Audouin's Gull Larus audouinii chicks. Butlletí del Grup Català d'Anellament 14: 65-67. Oro, D.; Baccetti, N.; Boukhalfa, D.; Eken, G.; El Hili, A.; Goutner, V.; Karauz, S.; Papaconstantinou, C.; Recorbet, B.; Ruiz, X. 2000. Current breeding distribution and status of Audouin's gulls Larus audouinii in the Mediterranean. In: Sultana, J.; Yésou, P. (ed.), Monitoring and Conservation of Birds, Mammals and Sea Turtles of the Mediterranean and Black Seas, pp. 69-80. BirdLife Malta. Oro, D.; Cam, E.; Pradel, R.; Martínez-Abrain, A. 2004. Influence of food availability on demography and local population dynamics in a long-lived seabird. Proceedings of the Royal Society of London Series B 271: 387-396. Oro, D.; Martínez-Abraín, A. 2007. Deconstructing myths on large gulls and their impact on threatened species. Animal Conservation 10: 117-126. Oro, D.; Martínez-Abraín, A.; Paracuellos, M.; Nevado, J.C.; Genovart, M. 2006. Influence of density-dependence on predator-prey seabird interactions at large spatio-temporal scales. Proceedings of the Royal Society of London Series B 273: 379-383. Oro, D.; Pradel, R. 2000. Determinants of local recruitment in a growing colony of Audouin's gull. Journal of Animal Ecology 69: 119-132. Oro, D.; Pradel, R.; Lebreton, J.-D. 1999. Food availability and nest predation influence life history traits in Audouin's gull, Larus audouinii. Oecologia 118: 438-445. Oro, D.; Ruxton, G. D. 2001. The formation and growth of seabird colonies: Audouin's gull as a case study. Journal of Animal Ecology 70: 527-535. Pedrocchi, V. Oro, D., Gonzalez-Solis, J., Ruiz, X., Jover, L. 2002. Differences in diet between the two largest breeding colonies of Andouin's gulls: the effects of fishery activities. Scientia Marina 66(3): 313-320. Recorbet, B.; Le Dru, A. 2002. Le Goéland d'Audouin Larus audouinii à Aspretto-Ajaccio (Corse): gestion pour une pérennisation de l'espèce sur un site artificiel. Alauda 70: 483-488. Rubinic, B.; Vrezec, A. 2001. Audouin's Gull Larus audouinii, a new breeding gull species in the Adriatic sea (Croatia). Acrocephalus 21: 219-222. Sanpera, C.; Ruiz, X.; Moreno, R.; Jover, L.; Waldron, S. 2007. Mercury and stable isotopes in feathers of Audouin's Gulls as indicators of feeding habits and migratory connectivity. Condor 109(2): 268-275. Sériot, J. 1996-1998. Following numbers of rare and endangered breeding birds in France 1995, 1996 and 1997. Tavecchia, G., Pradel, R., Genovart, M., Oro, D., 2007. Density-dependent parameters and demographic equilibrium in open populations. Oikos 116: 1481–1492. Travichon, S. 2004. Cycle de reproduction du Goéland d'Audouin Larus audouinii sur un site artificiel en Corse (France). Alauda 72: 227-233. |
| Citation: | BirdLife International 2010. Larus audouinii. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 21 May 2012. |
| Disclaimer: | To make use of this information, please check the <Terms of Use>. |
| Feedback: | If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided |