Sandwich Tern Thalasseus sandvicensis


Taxonomic note
Thalasseus sandvicensis (del Hoyo and Collar 2014) was previously placed in the genus Sterna.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: # _the_WP15.xls#.
Cramp, S. and Simmons, K.E.L. (eds). 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2018 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass 192.0 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 85,000,000 medium
Extent of Occurrence non-breeding (km2) 126,000,000 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals poor estimated 2012
Population trend Stable suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Largest subpopulations - - -
Generation length (yrs) 10.8 - - -

Population justification: The global population is estimated at 490,000-640,000 individuals (Wetlands International 2015). Within this, the European population is estimated at 79,900-148,000 pairs, which equates to 160,000-295,000 mature individuals (BirdLife International 2015).

Trend justification: The overall population trend is fluctuating, although some populations are stable, others have unknown trends (Wetlands International 2015). This species has undergone a small or statistically insignificant increase over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). Note, however, that these surveys cover less than 50% of the species's range in North America. The European population is also estimated to be fluctuating (BirdLife International 2015).

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Albania N Extant Yes
Algeria N Extant
Angola N Extant
Anguilla (to UK) N Extant
Antigua and Barbuda N Extant
Argentina N Extant
Aruba (to Netherlands) N Extant
Azerbaijan N Extant Yes Yes
Bahamas N Extant
Bahrain N Extant Yes Yes
Barbados N Extant
Belgium N Extant Yes
Belize N Extant
Benin N Extant
Bermuda (to UK) V Extant
Bonaire, Sint Eustatius and Saba (to Netherlands) N Extant Yes
Bosnia and Herzegovina V Extant
Brazil N Extant
Bulgaria N Extant Yes
Cameroon N Extant
Cape Verde N Extant
Cayman Islands (to UK) N Extant
Chile N Extant
Colombia N Extant
Congo N Extant
Congo, The Democratic Republic of the N Extant
Costa Rica N Extant Yes
Côte d'Ivoire N Extant
Croatia N Extant Yes
Cuba N Extant
Curaçao (to Netherlands) N Extant Yes
Cyprus N Extant Yes
Czechia V Extant
Denmark N Extant Yes Yes
Djibouti V Extant
Dominica N Extant
Dominican Republic N Extant
Ecuador N Extant
Egypt N Extant
El Salvador N Extant
Equatorial Guinea N Extant Yes
Eritrea N Extant
Estonia N Extant Yes
Ethiopia V Extant
Falkland Islands (Malvinas) V Extant
Faroe Islands (to Denmark) V Extant
Finland V Extant
France N Extant Yes Yes
French Guiana N Extant
Gabon N Extant
Gambia N Extant
Germany N Extant Yes Yes
Ghana N Extant
Gibraltar (to UK) N Extant Yes
Greece N Extant Yes Yes
Grenada N Extant
Guadeloupe (to France) N Extant
Guatemala N Extant
Guinea N Extant
Guinea-Bissau N Extant
Guyana N Extant
Haiti N Extant
Honduras U Extant
Hungary V Extant
Iceland V Extant
India N Extant
Iran, Islamic Republic of N Extant Yes Yes
Iraq N Extant Yes
Ireland N Extant Yes
Israel N Extant
Italy N Extant Yes Yes
Jamaica N Extant
Jordan N Extant Yes
Kazakhstan N Extant Yes
Kenya N Extant
Kuwait N Extant Yes Yes
Latvia N Extant
Lebanon N Extant Yes Yes
Liberia N Extant
Libya N Extant
Malta N Extant Yes
Martinique (to France) N Extant
Mauritania N Extant
Mexico N Extant
Montenegro V Extant
Montserrat (to UK) N Extant
Morocco N Extant
Mozambique N Extant
Namibia N Extant
Netherlands N Extant Yes
Nicaragua N Extant
Nigeria N Extant
North Macedonia N Extant Yes
Norway N Extant Yes
Oman N Extant Yes Yes
Pakistan N Extant
Palestinian Authority Territories N Extant Yes Yes
Panama N Extant
Peru N Extant
Poland N Extant Yes Yes
Portugal N Extant Yes Yes
Puerto Rico (to USA) N Extant
Qatar N Extant Yes Yes
Romania N Extant Yes Yes
Russia N Extant Yes
Russia (European) N Extant Yes
São Tomé e Príncipe N Extant
Saudi Arabia N Extant Yes Yes
Senegal N Extant
Serbia V Extant
Seychelles V Extant
Sierra Leone N Extant
Sint Maarten (to Netherlands) U Extant
Slovakia V Extant
Slovenia N Extant Yes
Somalia V Extant
South Africa N Extant
Spain N Extant Yes Yes
Sri Lanka N Extant
St Barthelemy (to France) N Extant
St Kitts and Nevis N Extant
St Lucia N Extant
St Martin (to France) U Extant
St Pierre and Miquelon (to France) V Extant Yes
St Vincent and the Grenadines N Extant
Sudan N Extant Yes
Suriname N Extant
Svalbard and Jan Mayen Islands (to Norway) V Extant
Sweden N Extant Yes
Switzerland N Extant
Syria N Extant Yes
Tanzania N Extant
Togo N Extant
Trinidad and Tobago N Extant
Tunisia N Extant Yes
Turkey N Extant Yes
Turkmenistan N Extant Yes
Turks and Caicos Islands (to UK) N Extant Yes
Ukraine N Extant Yes Yes
United Arab Emirates N Extant Yes Yes
United Kingdom N Extant Yes
Uruguay N Extant Yes
USA N Extant Yes
Venezuela N Extant
Virgin Islands (to UK) N Extant Yes
Virgin Islands (to USA) N Extant Yes
Western Sahara N Extant
Yemen N Extant Yes Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Aruba (to Netherlands) Oranjestad Reef Islands
Aruba (to Netherlands) San Nicolas Bay Reef Islands
Azerbaijan Kura Delta
Azerbaijan Pirsagat Islands and Los Island
Azerbaijan Shahdidi spit
Azerbaijan Yashma Island
Bahamas Cay Sal Marine Managenent Area
Bahamas Great Inagua
Bahamas Guana Cays
Belgium Voorhaven Zeebrugge and Baai van Heist
Bonaire, Sint Eustatius and Saba (to Netherlands) Pelkermeer Saltworks, Bonaire
Bonaire, Sint Eustatius and Saba (to Netherlands) Washington-Slagbaai National Park, Bonaire
Brazil Ilhas Comprida e Cananéia
Brazil Ilhas do Litoral Sul do Espírito Santo
Bulgaria Atanasovsko Lake
Bulgaria Pomorie Lake
Croatia Kvarner Islands
Croatia NW Dalmatia and Pag Island
Croatia Western Istrian Maritime Zone
Cuba Cayería Centro - Oriental de Villa Clara
Denmark Eastern German Bight
Denmark Hirsholmene
Denmark Nissum Fjord
Denmark Odense Fjord
Denmark Ringkøbing Fjord
Denmark Skallingen and Langli
Dominican Republic Jaragua National Park
Estonia Pärnu bay (NEW)
Estonia Väinameri
France Archipel des Glénan
France Baie des Veys et Marais du Cotentin
France Baies de Morlaix et de Carantec
France Bassin d'Arcachon et Banc d'Arguin
France Camargue
France Cap Gris-nez
France Cordon lagunaire de Sète à Agde
France Estuaire et embouchure de la Seine
France Ile de Goulmedec
France Iles Chausey
France Iles de la Colombière, de la Nellière et des Haches
France Ilôts de Trévorc'h
France Littoral Augeron
France Petite Camargue laguno-marine
French Guiana Amana
French Guiana Amana - Marine
French Guiana Connétable
French Guiana Connétable - Marine
French Guiana Plaine Kaw et Pointe Béhague
Gambia Niumi National Park
Gambia Tanji River (Karinti) Bird Reserve
Germany Coast and lagoons of Western Pomerania
Germany Eastern part of German Bight (with Heligoland)
Germany Eastern part of Kiel Bight
Germany Greifswalder Bodden
Germany Großer and Kleiner Jasmunder Bodden with Schmachter See and Nonnensee
Germany Hamburg Wadden Sea National Park
Germany Lower Saxonian North Sea off the East Frisian Islands
Germany Lower Saxony Wadden Sea National Park
Germany Schleswig-Holstein Wadden Sea National Park (includes the Halligs, Kniepsand/Amrum, Lister Koog, Rantumbecken, Rickelsb
Germany Wagbach lowlands
Germany Wismar bay and Salzhaff
Ghana Densu Delta Ramsar Site and vicinity
Ghana Keta Lagoon Ramsar Site
Ghana Muni-Pomadze Ramsar Site
Ghana Sakumo Lagoon Ramsar Site and vicinity
Ghana Songor Ramsar Site
Greece Amvrakikos gulf
Iran, Islamic Republic of Miankaleh Peninsula and Gorgan Bay
Ireland Connemara Islands
Ireland Greer's Island (Massmount), Mulroy Bay
Ireland Lady's Island Lake
Ireland Lough Swilly including Blanket Nook and Inch Lake
Italy Argentario, Laguna di Orbetello Lagoon e Lago di Burano
Italy Cagliari wetlands
Italy Circeo National Park and Pontine islands
Italy Pantani di Vendicari e di Capo Passero
Italy Po Delta
Italy Simeto mouth and middle course and Biviere di Lentini
Italy Tarquinia saltpans
Italy Uccellina mountains, Trappola marshes and Ombrone mouth
Italy Valle Bertuzzi and Goro lagoon
Italy Valli di Comacchio and Bonifica del Mezzano
Italy Venice lagoon
Jamaica Black River Great Morass
Kazakhstan Tyulen’i (Seal) Islands
Mauritania Banc d'Arguin National Park
Mauritania Cap Blanc
Mexico Humedales Costeros del Norte de la Península de Yucatán
Mexico Ría Lagartos
Morocco Dakhla area
Namibia Sandwich Harbour
Netherlands Grevelingen
Netherlands Griend
Netherlands Texel: Schorren and Zeeburg
Netherlands Westerschelde & Saeftinghe
Netherlands Westplaat
Oman Barr al Hikman
Oman Duqm
Oman Masirah island
Oman Ras al Hadd
Poland Puck Bay
Poland Vistula river mouth
Puerto Rico (to USA) Suroeste
Romania Black Sea
Romania Danube Delta
Russia (European) Delta of the Kuban' river
Russia (European) Khanskoye Lake
Russia (European) Kiziltash limans
Russia (European) Maly Zhemchuzhny island
Russia (European) Sulakskaya bay
Russia (European) Yeiski salt-lakes
Saudi Arabia Abu Ali
Senegal Cap Vert
Senegal Delta du Saloum
South Africa Berg River Estuary
South Africa False Bay Nature Reserve
Spain Albufera de Valencia marshes
Spain Cape Busto-Luanco
Spain Cape Candelaria-Ortigueira estuary-Cape Estaca de Bares
Spain Coast between Arinaga and Castillo del Romeral
Spain Costa da Morte
Spain Ebro delta
Spain Estrecho de Gibraltar
Spain Plataforma Marina del Delta del Ebro - Columbretes
Spain Sotavento beach
St Vincent and the Grenadines Mustique Island
Tunisia Îles Kneiss
Tunisia Salines de Thyna
Turkey Gediz Delta
Turks and Caicos Islands (to UK) Caicos Bank Southern Cays
Turks and Caicos Islands (to UK) Grand Turk Salinas and Shores
Turks and Caicos Islands (to UK) North, Middle and East Caicos Ramsar Site
Turks and Caicos Islands (to UK) Salt Cay Creek and Salinas
Ukraine Berdyans'ka peninsula
Ukraine Bilosarajs'ka peninsula
Ukraine Karkinits'ka and Dzharylgats'ka bays
Ukraine Kryva peninsula
Ukraine Kuyal'nyts'kyj lyman
Ukraine Obytichna peninsula
Ukraine Syvash Bay
Ukraine Yagorlyts'ka and Tendrivs'ka Bays
United Kingdom Carlingford Lough
United Kingdom Chichester and Langstone Harbours
United Kingdom Coquet Island
United Kingdom Dee Estuary
United Kingdom Duddon Estuary
United Kingdom Dungeness To Pett Levels
United Kingdom East Sanday
United Kingdom Farne Islands
United Kingdom Firth of Forth Islands
United Kingdom Larne Lough
United Kingdom Medway Estuary and Marshes
United Kingdom North Norfolk Coast
United Kingdom Poole Harbour
United Kingdom Solent Marshes and Southampton Water
United Kingdom Strangford Lough and islands
United Kingdom Ynys Feurig, Cemlyn Bay and the Skerries
United Kingdom Ythan Estuary, Sands of Forvie and Meikle Loch
USA Altamaha River Delta
USA Big Foot Island
USA Big Marco Pass Shoal
USA Bird Key Stono
USA Cape Romain National Wildlife Refuge
USA Chandeleur Islands (Breton National Wildlife Refuge)
USA Deveaux Bank
USA Ferry Slip Island
USA Isles Dernieres - Timbalier Islands
USA Jigsaw Islands
USA Sand Bag Island
USA Sundown Island
USA Tomkins Island
Venezuela Parque Nacional Archipiélago Los Roques
Venezuela Pedernales-Capure
Venezuela Pedernales-Capure - Marine
Virgin Islands (to UK) Anegada: Western salt ponds and coastal areas
Virgin Islands (to USA) Saba Island and Cays

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Intertidal Mud Flats and Salt Flats suitable breeding
Marine Intertidal Rocky Shoreline major non-breeding
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc major non-breeding
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc major breeding
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches major breeding
Marine Neritic Coral Reef - Back Slope suitable breeding
Marine Neritic Coral Reef - Foreslope (Outer Reef Slope) suitable breeding
Marine Neritic Coral Reef - Inter-Reef Rubble Substrate suitable breeding
Marine Neritic Coral Reef - Inter-Reef Soft Substrate suitable breeding
Marine Neritic Coral Reef - Lagoon suitable breeding
Marine Neritic Coral Reef - Outer Reef Channel suitable breeding
Marine Neritic Estuaries suitable non-breeding
Marine Neritic Estuaries suitable breeding
Marine Neritic Macroalgal/Kelp major non-breeding
Marine Neritic Macroalgal/Kelp major breeding
Marine Neritic Pelagic suitable non-breeding
Marine Neritic Pelagic suitable breeding
Marine Neritic Seagrass (Submerged) major non-breeding
Marine Neritic Seagrass (Submerged) major breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major non-breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major breeding
Marine Neritic Subtidal Rock and Rocky Reefs major non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs major breeding
Marine Neritic Subtidal Sandy major non-breeding
Marine Neritic Subtidal Sandy major breeding
Marine Neritic Subtidal Sandy-Mud major non-breeding
Marine Neritic Subtidal Sandy-Mud major breeding
Marine Oceanic Epipelagic (0-200m) marginal resident
Marine Oceanic Mesopelagic (200-1000m) marginal resident
Altitude 0 - 50 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Species disturbance, Reduced reproductive success, Species mortality
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Species disturbance, Reduced reproductive success

Purpose Primary form used Life stage used Source Scale Level Timing
Food (human) Whole Adults and juveniles Wild Non-trivial Recent
Food (human) Whole Eggs Wild Non-trivial Recent
Food - human - - - Non-trivial Recent
Food - human - - Non-trivial Recent
Sport Whole Adults and juveniles Wild Non-trivial Recent
Sport hunting/specimen collecting - - - Non-trivial Recent
Sport hunting/specimen collecting - - Non-trivial Recent

Recommended citation
BirdLife International (2019) Species factsheet: Thalasseus sandvicensis. Downloaded from on 19/10/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from on 19/10/2019.