|Scientific Name:||Sternula albifrons (Pallas, 1764)|
Sterna albifrons Pallas, 1764
Sternula albifrons Christidis and Boles (2008)
Sternula albifrons AOU checklist (1998 + supplements)
|Taxonomic Source(s):||Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.|
|Taxonomic Notes:||Sternula albifrons (del Hoyo and Collar 2014) was previously placed in the genus Sterna.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Facilitator/Compiler(s):||Ashpole, J, Butchart, S., Calvert, R., Ekstrom, J., Hatchett, J., Malpas, L.|
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
|Previously published Red List assessments:|
|Range Description:||Breeding populations of this species can be found through much of Europe, scattered along the coast and inland in parts of Africa, in much of western, central and the extreme east and south of Asia, and in northern parts of Australasia. Migratory individuals expand the range to include most of the coast of Africa, the Arabian Peninsula, the western coast of India and most of the waters of south-east Asia and Australasia, including New Zealand. One seasonally breeding colony is also present on Hawaii (del Hoyo et al. 1996).|
Native:Afghanistan; Albania; Algeria; Armenia; Australia; Austria; Azerbaijan; Bahrain; Bangladesh; Belarus; Belgium; Benin; Bosnia and Herzegovina; British Indian Ocean Territory; Brunei Darussalam; Bulgaria; Burundi; Cambodia; Cameroon; Chad; China; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Croatia; Cyprus; Czech Republic; Denmark; Djibouti; Egypt; Equatorial Guinea; Eritrea; Estonia; Finland; France; Gabon; Gambia; Georgia; Germany; Ghana; Gibraltar; Greece; Guam; Guinea; Guinea-Bissau; Hong Kong; Hungary; India; Indonesia; Iran, Islamic Republic of; Iraq; Ireland; Israel; Italy; Japan; Jordan; Kazakhstan; Kenya; Korea, Democratic People's Republic of; Korea, Republic of; Kuwait; Kyrgyzstan; Lao People's Democratic Republic; Latvia; Liberia; Libya; Lithuania; Macedonia, the former Yugoslav Republic of; Malaysia; Mali; Marshall Islands; Mauritania; Mauritius; Micronesia, Federated States of ; Moldova; Mongolia; Montenegro; Morocco; Mozambique; Myanmar; Nepal; Netherlands; New Zealand; Niger; Nigeria; Northern Mariana Islands; Norway; Oman; Pakistan; Palau; Palestinian Territory, Occupied; Papua New Guinea; Philippines; Poland; Portugal; Qatar; Romania; Russian Federation (Central Asian Russia, Eastern Asian Russia, European Russia); Saudi Arabia; Senegal; Serbia; Singapore; Slovakia; Slovenia; Solomon Islands; Somalia; South Africa; Spain; Sri Lanka; Sweden; Switzerland; Syrian Arab Republic; Taiwan, Province of China; Tajikistan; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tunisia; Turkey; Turkmenistan; Ukraine; United Arab Emirates; United Kingdom; Uzbekistan; Viet Nam; Western Sahara
Vagrant:Angola; Burkina Faso; Cape Verde; Colombia; Faroe Islands; Fiji; Kiribati; Lebanon; Luxembourg; Maldives; Malta; Namibia; New Caledonia; Samoa; Seychelles; Sierra Leone; United States; Yemen
Present - origin uncertain:Sudan
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The global population is estimated to number c.190,000-410,000 individuals (Wetlands International 2015). The European population is estimated at 36,000-53,000 pairs, which equates to 71,900-106,000 mature individuals (BirdLife International 2015). National population estimates include: c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in China; c.100-10,000 breeding pairs, c.50-1,000 individuals on migration and c.50-1,000 wintering individuals in Taiwan; c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Korea and c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Japan (Brazil 2009).|
Trend Justification: The overall population trend is decreasing, although some populations have unknown or increasing trends (Wetlands International 2015). In Europe the population size trend is unknown (BirdLife International 2015).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Behaviour This is a strongly migratory (del Hoyo et al. 1996) coastal seabird which usually fishes in very shallow water only a few centimetres deep, often over the advancing tideline or in brackish lagoons and saltmarsh creeks. It has the most inshore distribution of all terns. It breeds between May and July (Richards 1990) in solitary pairs (Flint et al. 1984) or small monospecific groups (del Hoyo et al. 1996) usually of 1-15 pairs (del Hoyo et al. 1996, Snow and Perrins 1998) (rarely over 40 pairs) (del Hoyo et al. 1996) occasionally amidst colonies of other terns (Flint et al. 1984). Breeding may be timed to coincide with peak fish abundance (Perrow et al 2006). Northern breeders depart the breeding grounds from late-July onwards (Richards 1990, del Hoyo et al. 1996), travelling first to moulting sites where they form large roosts before continuing southwards (Tavecchia et al. 2006). The species is gregarious throughout the year (Snow and Perrins 1998) and usually feeds singly, in small groups or larger scattered flocks (Snow and Perrins 1998) and congregating in many thousands on passage in small wetlands where fish fry are abundant (del Hoyo et al. 1996). Habitat Breeding The species breeds on barren or sparsely vegetated beaches, islands and spits of sand, shingle (del Hoyo et al. 1996), shell fragments, pebbles (Flint et al. 1984), rocks or coral fragments (del Hoyo et al. 1996) on seashores (Flint et al. 1984) or in estuaries, saltmarshes, saltpans, offshore coral reefs (del Hoyo et al. 1996), rivers, lakes (Flint et al. 1984, del Hoyo et al. 1996) and reservoirs (de Silva 1991). It may also nest on dry mudflats in grassy areas (de Silva 1991, del Hoyo et al. 1996) but shows a preference for islets surrounded by saline or fresh water where small fish can be caught without the need for extensive foraging flights (Snow and Perrins 1998). Non-breeding Outside of the breeding season the species frequents tidal creeks, coastal lagoons and saltpans and may foraging at sea (del Hoyo et al. 1996) up to 15 km offshore (Urban et al. 1986). Diet Its diet consists predominantly of small fish (e.g. Ammodytes spp., roach Rutilus rutilus, rudd Scardinius erythrophthalmus, carp Cyprinus carpio and perch Perca fluviatilis) and crustaceans 3-6 cm long as well as insects, annelid worms and molluscs (del Hoyo et al. 1996). In Scotland, Little Terns feed mainly on small fish and invertebrates, including herring, sandeel, and shrimps (Crangon vulgaris) (BirdLife International 2000). In Portugal, birds were found to feed mainly on sand-smelts (Atherina spp.) and gobies (Pomatoschistus spp.), which were the most abundant fish species in the study areas (Catry et al 2006). On Rigby Island, Australia, chicks were fed entirely on juvenile fish of the families Clupeidae, Engraulidae, Pomatomidae and Carangidae, including pilchard, southern anchovy and blue sprat (Taylor and Roe 2004). Breeding site The nest is a bare scrape (Richards 1990) positioned on the ground in less than 15 % vegetation cover (del Hoyo et al. 1996) on beaches of sand, pebbles, shingle, shell fragments, coral fragments or rock (Flint et al. 1984, del Hoyo et al. 1996) above the high tide-line and often only a few metres away from shallow clear water (Snow and Perrins 1998). Alternatively in more marshy habitats (e.g. coastal saltmarshes) the species may build a nest of shells or vegetation (del Hoyo et al. 1996). The species nests in small loose colonies, with neighbouring nests usually placed more than 2 m apart (del Hoyo et al. 1996). Foraging range In Spain, 95% of foraging terns were observed less than 4 km away from the nearest colony (Bertolero et al 2005). However, the foraging range of individuals varies according to whether they are currently breeding. In Norfolk, UK, birds with an active nest occupied a range of <6.3 km2 with a range span of up to 4.6 km (Perrow et al 2006), whereas failed birds ranged widely, travelling up to 27 km in a single foraging bout (Perrow et al 2006). In Portugal, ranges were found to be significantly greater during incubation (April-May) than during chick rearing (June-July) (Paiva et al 2007). Little Terns prefer channels and lagoons for foraging, rather than deeper marine habitats (Bertolero et al 2005, Paiva et al 2007). They also prefer areas with abundant resources, entrance channels and main lagoon channels with strong currents, and areas with alternative feeding resources nearby (Paiva et al 2007). Areas subjected to strong human pressure (Paiva et al 2007) and salt marshes (Bertolero et al 2005) are avoided. The species tends to forage preferentially at low tide (Paiva et al 2007).|
|Systems:||Terrestrial; Freshwater; Marine|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Generation Length (years):||10.9|
|Movement patterns:||Full Migrant|
|Congregatory:||Congregatory (and dispersive)|
|Major Threat(s):||The species is threatened by habitat destruction (Barcena et al. 1984) such as the development and industrial reclamation of coastal breeding habitats (Barcena et al. 1984, del Hoyo et al. 1996) (e.g. for the development of new harbour facilities) (Barcena et al. 1984). It is also highly vulnerable to human disturbance (including birdwatchers) at coastal and inland nesting sites which can lead to nest failures (Barcena et al. 1984, del Hoyo et al. 1996). Pesticide pollution (e.g. organochlorine pollutants, mercury and DDT) (Barcena et al. 1984, Thyen et al. 2000, Choi et al. 2001) and artificially induced water-level fluctuations in saltmarshes (Barcena et al. 1984) may also pose a threat to the species's reproductive success (Barcena et al. 1984, Thyen et al. 2000, Choi et al. 2001). The species also suffers from local egg collecting (Barcena et al. 1984) and is susceptible to avian influenza so may be threatened by future outbreaks of the virus (Melville and Shortridge 2006).|
Conservation Actions Underway
The species is listed in Appendix II of the Convention on Migratory Species and is covered under the African Eurasian Waterbird Agreement. It is on Annex II of the Bern Convention. Within the EU it is listed on Annex I of the Birds Directive. Protective measures such as fencing-off sensitive nesting areas, erecting warning signs and wardening are effective measures of increasing the breeding success of this species on sandy beaches (Richards 1990, Medeiros et al. 2007). There is also evidence that earlier breeders benefit more (i.e. have higher reproductive success) from protective measures, suggesting that conservation efforts can be maximised if concentrated earlier in the season (Medeiros et al. 2007). Breeding pairs are also known to be attracted to coastal locations where artificial nesting sites have been constructed (e.g. beaches of bare shingle and islands or rafts covered with sparse vegetation) (Burgess and Hirons 1992). A conservation scheme for the protection of gull and tern breeding colonies in coastal lagoons and deltas (e.g. Po Delta, Italy) involves protection from human disturbance, prevention of erosion of islet complexes, habitat maintenance and the creation of new islets for nest sites (Fasola and Canova 1996). The scheme particularly specifies that small bare islets of 0.1-0.8 ha with very reduced vegetation cover (less than 30 %) and sward heights less than 20 cm should be maintained or created as additional nesting sites for this species (Fasola and Canova 1996). Within Europe there are 258 Important Bird Areas identified across the European region. Within the EU there are 648 Special Protection Areas which include this species.
Conservation Actions Proposed
The following information refers to the species's European range only: Management of existing Special Protection Areas, including continuing measures to reduce human disturbance to breeding sites.
|Citation:||BirdLife International. 2016. Sternula albifrons. The IUCN Red List of Threatened Species 2016: e.T22694656A86737634.Downloaded on 22 October 2017.|
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