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

Taxonomic source(s)
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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2018	Near Threatened	D1
2016	Near Threatened	D1
2012	Near Threatened	D1
2010	Near Threatened	D1
2008	Near Threatened	C1
2006	Near Threatened
2004	Near Threatened
2000	Lower Risk/Near Threatened
1996	Vulnerable
1994	Vulnerable
1988	Threatened

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)	398,000 km2	medium
Extent of Occurrence (non-breeding)	1,670,000 km2	medium
Area of Occupancy (breeding/resident)	7,700 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2300-4300 mature individuals	medium	estimated	1993
Population trend	stable	poor	suspected	-
Generation length	11 years	-	-	-

Population justification: The total population has been estimated at 3,500-6,500 individuals, roughly equivalent to 2,300-4,300 mature individuals (Jouventin et al. 1988).

Trend justification: The South African population is listed in the Regional Red Data Book as Critically Endangered (Taylor and Wanless 2015), due to the apparent loss of the population on Prince Edward Island. There are no recent counts from the main breeding area on Kerguelen (V. Bretagnolle in litt. 1999) and thus population trends are unknown, but it is assumed that the species is overall stable and not undergoing any significant decline.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
French Southern Territories	extant	native		yes
Heard Island and McDonald Islands (to Australia)	extant	uncertain
South Africa	extant	native		yes

Country/Territory	IBA Name
French Southern Territories	Baie Larose
French Southern Territories	Île de l'Est
French Southern Territories	Île de la Possession
French Southern Territories	Île des Pingouins
French Southern Territories	Île Foch, Île Sainte Lanne Gramont and Île Howe
French Southern Territories	Îles des Apôtres
French Southern Territories	Îles Nuageuses and Île Clugny
French Southern Territories	Islands of the Golfe du Morbihan
French Southern Territories	Northern part of Péninsule Loranchet
French Southern Territories	Péninsule Courbet
French Southern Territories	Péninsule Rallier du Baty
South Africa	Prince Edward Islands Special Nature Reserve

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Subantarctic	suitable	breeding
Marine Neritic	Macroalgal/Kelp	major	resident
Marine Neritic	Pelagic	marginal	resident
Marine Neritic	Seagrass (Submerged)	major	resident
Marine Neritic	Subtidal Loose Rock/pebble/gravel	major	resident
Marine Neritic	Subtidal Rock and Rocky Reefs	major	resident
Marine Neritic	Subtidal Sandy	major	resident
Marine Neritic	Subtidal Sandy-Mud	major	resident
Rocky areas (eg. inland cliffs, mountain peaks)		suitable	breeding
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Catharacta antarctica	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species disturbance, Reduced reproductive success, Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Kerguelen Tern Sterna virgata. Downloaded from https://datazone.birdlife.org/species/factsheet/kerguelen-tern-sterna-virgata on 22/11/2024.
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 22/11/2024.