Gelochelidon nilotica -- (Gmelin, 1789)ANIMALIA -- CHORDATA -- AVES -- CHARADRIIFORMES -- LARIDAECommon names: Common Gull-billed Tern;

European Red List AssessmentEuropean Red List Status

LC -- Least Concern, (IUCN version 3.1)

Assessment InformationYear published: 2015Date assessed: 2015-03-31Assessor(s): BirdLife InternationalReviewer(s): Symes, A.Compiler(s): Ashpole, J., Burfield, I., Ieronymidou, C., Pople, R., Wheatley, H. & Wright, L.Assessment RationaleEuropean regional assessment: Least Concern (LC)EU27 regional assessment: Least Concern (LC)

At both European and EU27 scales this species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (30% decline over ten years or three generations).

For these reasons the species is evaluated as Least Concern within both Europe and the EU27.

OccurrenceCountries/Territories of OccurrenceNative:Armenia; Azerbaijan; Bulgaria; Denmark; France; Germany; Greece; Italy; Portugal; Romania; Russian Federation; Spain; Turkey; UkraineVagrant:Belgium; Bosnia and Herzegovina; Croatia; Finland; Hungary; Ireland, Rep. of; Luxembourg; Montenegro; Norway; Poland; Serbia; Slovakia; Slovenia; Sweden; United Kingdom

PopulationThe European population is estimated at 16,600-21,200 pairs, which equates to 33,200-42,400 mature individuals. The population in the EU27 is estimated at 8,000-9,200 pairs, which equates to 16,100-18,300 mature individuals. For details of national estimates, see Supplementary PDF.

TrendIn Europe and the EU27 the population size is estimated to be increasing. For details of national estimates, see Supplementary PDF.

Habitats and EcologyIt breeds in a variety of locations with bare or sparsely vegetated islands, banks, flats, or spits of dry mud and sand (Higgins and Davies 1996) including barrier beaches (shoals), dunes, saltmarshes, saltpans, freshwater lagoons (Gochfield and Burger 1996), estuaries, deltas, inland lakes, rivers and marshes (Snow and Perrins 1998). During this season it may also feed on emerging insects over lakes, agricultural fields, grasslands and even over semi-desert regions (Gochfield and Burger 1996). On passage the species typically forages over saltpans, coastal lagoons, mudflats, marshes and wet fields, overwintering on estuaries, saltpans (Gochfield and Burger 1996), lagoons (Snow and Perrins 1998) and saltmarshes (Higgins and Davies 1996) or in more inland sites such as large rivers, lakes (Snow and Perrins 1998), sewage ponds, reservoirs, saltpans and irrigation canals (Higgins and Davies 1996). The species is loosely colonial; usually 5–50 pairs found together. It will often nest in the colonies of other terns or Larus ridibundus. Egg-laying occurs in May and June. The nest is a scrape in dry mud, sand or gravel (Richards 1990) on beaches, dry mudflats, dykes, sea-

wrack on the tideline or on floating vegetation (Gochfield and Burger 1996). It is an opportunistic feeder and is largely insectivorous taking adult and larval terrestrial and aquatic insects (Richards 1990, Gochfield and Burger 1996) as well as spiders, earthworms, small reptiles, frogs, small fish (6–9 cm long), aquatic invertebrates and rarely voles and small birds. Northern breeding populations of this species are migratory and European birds disperse in all directions after breeding, then migrate across to Spain, Italy and northern Africa to western Africa, the Rift Valley and coastal eastern Africa; others travel east to India, and occasionally Indonesia (Gochfield and Burger 1996).Habitats & Altitude

Habitat (level 1 - level 2) Importance OccurrenceArtificial/Aquatic - Irrigated Land (includes irrigation channels) suitable breedingArtificial/Aquatic - Water Storage Areas (over ha) major breedingMarine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes suitable breedingMarine Coastal/Supratidal - Coastal Freshwater Lakes suitable breedingMarine Coastal/Supratidal - Coastal Sand Dunes major breedingMarine Intertidal - Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc major breedingMarine Neritic - Estuaries suitable breedingWetlands (inland) - Permanent Freshwater Lakes (over ha) suitable breedingWetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls) suitable breedingWetlands (inland) - Seasonal/Intermittent Freshwater Lakes (over ha) suitable breedingAltitude max. 100 m Occasional altitudinal limits

ThreatsThe species is threatened by the deterioration and loss of habitat, e.g. through wetland drainage, agricultural intensification, pesticide pollution, fluctuating water levels (Gochfeld and Burger 1996), beach erosion and the development or modification of foraging sites (Molina and Erwin 2006). It also suffers from reduced reproductive success as a result of human disturbance at breeding colonies (Gochfeld and Burger 1996, Molina and Erwin 2006).Threats & Impacts

Threat (level 1) Threat (level 2) Impact and StressesAgriculture & aquaculture

Agro-industry farming

Timing Scope Severity ImpactOngoing Whole (>90%) Slow, Significant

DeclinesMedium Impact

StressesEcosystem conversion; Ecosystem degradation

Biological resource use

Hunting & trapping terrestrial animals (intentional use - species is the target)

Timing Scope Severity ImpactOngoing Majority (50-90%) Negligible declines Low Impact

StressesSpecies mortality

Human intrusions & disturbance

Work & other activities

Timing Scope Severity ImpactOngoing Majority (50-90%) Negligible declines Low Impact

StressesReduced reproductive success

Natural system modifications

Abstraction of surface water (unknown use)

Timing Scope Severity ImpactOngoing Whole (>90%) Negligible declines Medium Impact

StressesEcosystem conversion; Ecosystem degradation

Pollution Herbicides and pesticides

Timing Scope Severity ImpactPast, Unlikely to Return

Majority (50-90%) Slow, Significant Declines

Past Impact

StressesEcosystem conversion; Ecosystem degradation

ConservationConservation Actions UnderwayCMS Appendix II. EU Birds Directive Annex I. Bern Convention Appendix II. There are currently no known conservation measures for this species.

Conservation Actions ProposedIdentify important breeding areas for the species and ensure site protection from disturbance, development and modification. Develop and implement suitable site management plans. Studies should be conducted to investigate the species's population ecology and potential threats and impacts, in order to inform conservation measures.

BibliographyGochfeld, M. & Burger, J. (1996). Common Gull-billed Tern (Gelochelidon nilotica). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/54012 on 22 January 2015).Molina, K. C.; Erwin, R. M. 2006. The Distribution and Conservation Status of the Gull-billed Tern (Gelochelidon nilotica) in North America. Waterbirds 29(3): 271-295.Richards, A. 1990. Seabirds of the northern hemisphere. Dragon's World Ltd, Limpsfield, U.K.Snow, D. W.; Perrins, C. M. 1998. The Birds of the Western Palearctic vol. 1: Non-Passerines. Oxford University Press, Oxford.

Map (see overleaf)