• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of_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: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Least Concern
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

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	136,000,000 km2	medium
Extent of Occurrence (non-breeding)	86,300,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	16000 - 30000 mature individuals	medium	suspected	2019
Population trend	decreasing	-	suspected	-
Generation length	10.1 years	-	-	-

Population justification: The largest colonies with several thousand pairs are found on the Galápagos Islands (Ecuador) and in the Caribbean (del Hoyo et al. 1992, Orta et al. 2019), followed by approximately 1,000 pairs along the Pacific coast of Mexico (Hernández-Vázquez et al. 2018, Piña-Ortiz et al. 2018). The population in the southern Atlantic Ocean numbers less than 3,000 pairs, and those on Cape Verde and around the Arabian Peninsula contain a few hundred pairs (del Hoyo et al. 1992, Orta et al. 2019). The population size is therefore preliminarily estimated at 8,000-15,000 pairs, equating to 16,000-30,000 mature individuals.

Trend justification: The species’s current population trend is not very clear. It is suspected to be undergoing a decline, mainly due to the severe consequences of predation by cats and rats. So far, however, this threat was assumed to only affect a minority of the global population. New evidence suggests that predation is particularly severe in Caribbean breeding colonies, where a large part of the global population occurs (B. Denneman in litt. 2014, Orta et al. 2019). Unfortunately, in most cases, there is not much information available about the decline. For some breeding colonies, we know the direction of the population change, but have no data on its intensity or rate. For many other colonies, we have no information about the trend. The current trend in most of the colonies is thus unknown. Whilst it is therefore not possible to confidently determine the overall population trend for this species, it is precautionarily suspected to be undergoing a small decline.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Angola	extant	vagrant
Anguilla (to UK)	extant	native
Antigua and Barbuda	extant	native
Bahamas	extant	native
Bahrain	extant	uncertain
Barbados	extant	native
Belize	extant	uncertain
Benin	extant	uncertain
Bermuda (to UK)	extant	vagrant
Bonaire, Sint Eustatius and Saba (to Netherlands)	extant	native
Brazil	extant	native
Cameroon	extant	uncertain
Cape Verde	extant	native		yes
Cayman Islands (to UK)	extant	native
Chile	extant	native
China (mainland)	extant	native		yes
Colombia	extant	native
Congo	extant	uncertain
Congo, The Democratic Republic of the	extant	uncertain
Costa Rica	extant	vagrant
Côte d'Ivoire	extant	uncertain
Cuba	extant	native
Curaçao (to Netherlands)	extant	native
Djibouti	extant	native
Dominica	extant	native
Dominican Republic	extant	native
Ecuador	extant	native
Egypt	extant	native
El Salvador	extant	native
Equatorial Guinea	extant	uncertain
Eritrea	extant	native
French Guiana	extant	native
French Polynesia	extant	vagrant
Gabon	extant	vagrant
Gambia	extant	vagrant
Ghana	extant	uncertain
Grenada	extant	native		yes
Guadeloupe (to France)	extant	native
Guatemala	extant	uncertain
Guinea	extant	native
Guinea-Bissau	extant	native
Guyana	extant	uncertain
Haiti	extant	native
Honduras	extant	uncertain
India	extant	vagrant
Iran, Islamic Republic of	extant	native	yes
Iraq	extant	uncertain
Israel	extant	vagrant
Jamaica	extant	vagrant
Jordan	extant	vagrant
Kuwait	extant	vagrant			yes
Liberia	extant	uncertain
Madagascar	extant	vagrant
Malaysia	extant	vagrant
Maldives	extant	native
Martinique (to France)	extant	native
Mauritania	extant	vagrant
Mexico	extant	native
Montserrat (to UK)	extant	native
Myanmar	extant	vagrant
Netherlands	extant	vagrant
Nicaragua	extant	uncertain
Nigeria	extant	uncertain
Oman	extant	native	yes
Pakistan	extant	native
Panama	extant	native
Peru	extant	native
Portugal	extant	native		yes
Puerto Rico (to USA)	extant	native
Qatar	extant	native	yes
São Tomé e Príncipe	extant	uncertain
Saudi Arabia	extant	native	yes
Senegal	extant	native		yes
Seychelles	extant	vagrant
Sint Maarten (to Netherlands)	extant	native
Somalia	extant	native
South Africa	extant	vagrant
Spain	extant	vagrant
Sri Lanka	extant	vagrant
St Helena (to UK)	extant	native		yes
St Kitts and Nevis	extant	native
St Lucia	extant	native
St Martin (to France)	extant	native
St Vincent and the Grenadines	extant	native
Sudan	extant	vagrant			yes
Suriname	extant	uncertain
Togo	extant	uncertain
Trinidad and Tobago	extant	native
Turks and Caicos Islands (to UK)	extant	native
United Arab Emirates	extant	native		yes
United Kingdom	extant	vagrant
USA	extant	vagrant
Venezuela	extant	native
Vietnam	extant	vagrant
Virgin Islands (to UK)	extant	native	yes
Virgin Islands (to USA)	extant	native	yes
Western Sahara	extant	uncertain
Yemen	extant	native	yes

Country/Territory	IBA Name
Anguilla (to UK)	Dog Island
Anguilla (to UK)	Prickly Pear (East and West)
Bonaire, Sint Eustatius and Saba (to Netherlands)	Boven, Sint Eustatius
Bonaire, Sint Eustatius and Saba (to Netherlands)	Saba
Cape Verde	Coastal cliffs between Porto Mosquito and Baia do Inferno
Cape Verde	Coastal cliffs between Porto Mosquito and Baia do Inferno - Marine
Cape Verde	Ilhéus do Rombo
Cape Verde	Ponta do Sol Natural Reserve
Cape Verde	Raso / São Nicolau - marine
Cape Verde	Raso Islet Integral Natural Reserve
Cape Verde	Serra Negra
Ecuador	Áreas costeras de Fernandina y del occidente de Isabela
Ecuador	Isla Española
Ecuador	Isla Floreana
Ecuador	Isla San Cristóbal
Guadeloupe (to France)	Falaises du Nord Grande-Terre
Guadeloupe (to France)	Falaises Nord et Îlet de Vieux-Fort de Marie-Galante
Guadeloupe (to France)	Pointe des Châteaux
Mexico	Islas Revillagigedo
Oman	Halaaniyaat Islands
Oman	Khor Mughsayl
Oman	Musandam islands
Senegal	Parc National des Iles de la Madeleine
St Helena (to UK)	Boatswainbird Island
St Helena (to UK)	Great Stone Top and Shore Island
St Helena (to UK)	Ladder Hill
St Lucia	Iyanola and Grande Anses, Esperance and Fond D'ors
St Lucia	Point Sables
St Martin (to France)	Tintamarre
Trinidad and Tobago	Little Tobago Island
Trinidad and Tobago	St Giles Islands
United Arab Emirates	Qarnain Island
Virgin Islands (to USA)	North-west Cays
Yemen	Abd al-Kuri (Socotra)
Yemen	Darsa
Yemen	Falang - Momi coast and cliffs (Socotra)
Yemen	Islands north of Al-Hudaydah
Yemen	Jaza'ir al-Hanish
Yemen	Kal Farun (Socotra)
Yemen	Sabuniya (Socotra)
Yemen	Samha

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Coastal/Supratidal	Sea Cliffs and Rocky Offshore Islands	major	breeding
Marine Neritic	Macroalgal/Kelp	major	breeding
Marine Neritic	Macroalgal/Kelp	major	non-breeding
Marine Neritic	Pelagic	major	breeding
Marine Neritic	Pelagic	major	non-breeding
Marine Neritic	Seagrass (Submerged)	major	breeding
Marine Neritic	Seagrass (Submerged)	major	non-breeding
Marine Neritic	Subtidal Loose Rock/pebble/gravel	major	breeding
Marine Neritic	Subtidal Loose Rock/pebble/gravel	major	non-breeding
Marine Neritic	Subtidal Rock and Rocky Reefs	major	breeding
Marine Neritic	Subtidal Rock and Rocky Reefs	major	non-breeding
Marine Neritic	Subtidal Sandy	major	breeding
Marine Neritic	Subtidal Sandy	major	non-breeding
Marine Neritic	Subtidal Sandy-Mud	major	breeding
Marine Neritic	Subtidal Sandy-Mud	major	non-breeding
Marine Oceanic	Epipelagic (0-200m)	major	breeding
Marine Oceanic	Epipelagic (0-200m)	major	non-breeding
Marine Oceanic	Mesopelagic (200-1000m)	major	breeding
Marine Oceanic	Mesopelagic (200-1000m)	major	non-breeding
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus norvegicus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Reduced reproductive success
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation

Purpose	Scale
Food - human	subsistence, national
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Red-billed Tropicbird Phaethon aethereus. Downloaded from https://datazone.birdlife.org/species/factsheet/red-billed-tropicbird-phaethon-aethereus on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.