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

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

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
C2a(i,ii); D	B2ab(iii,v); C2a(i,ii); D	B2ab(iii,v); C2a(i,ii); D1+2

Red List history

Year	Category	Criteria
2018	Critically Endangered	C2a(i,ii); D
2016	Critically Endangered	C2a(i,ii); D
2015	Critically Endangered	C2a(i,ii); D
2013	Critically Endangered	C2a(i,ii); D
2012	Critically Endangered	C2a(i,ii);D
2010	Critically Endangered	C2a(ii); D1
2009	Critically Endangered	B1a+b(iii); C2a(ii); D1
2008	Critically Endangered
2004	Critically Endangered
2000	Critically Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

Migratory status	full migrant	Forest dependency	does not normally occur in forest
Land-mass type	continent	Average mass	284 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	114,000 km2	medium
Extent of Occurrence (non-breeding)	4,370,000 km2	medium
Area of Occupancy (breeding/resident)	60 km2
Area of Occupancy (non-breeding)	6 km2
Number of locations	4	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	30-49 mature individuals	poor	estimated	2013
Population trend	decreasing	poor	suspected	-
Generation length	11 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The number of breeding adults varies each year, ranging from 12 in 2012 to at least 43 in 2014. Given this the total number of mature individuals is likely to number fewer than 50, and perhaps most likely 30-49 (S. Chan in litt. 2013).

Trend justification: Repeat surveys at the two known breeding sites since 2003 have shown an overall decrease in the number of breeding pairs.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
China (mainland)	extant	native		yes
Indonesia	extant	native			yes
Malaysia	extant	native			yes
Philippines	extant	native			yes
South Korea	extant	native		yes
Taiwan, China	extant	native		yes
Thailand	extant	native			yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Coastal/Supratidal	Coastal Brackish/Saline Lagoons/Marine Lakes	major	non-breeding
Marine Intertidal	Mud Flats and Salt Flats	major	resident
Marine Intertidal	Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc	major	resident
Marine Intertidal	Shingle and/or Pebble Shoreline and/or Beaches	major	resident
Marine Neritic	Pelagic	major	non-breeding
Marine Neritic	Subtidal Sandy-Mud	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Fishing & harvesting aquatic resources - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Species disturbance
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Rapid Declines		High Impact: 8
		Stresses Reduced reproductive success
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Reduced reproductive success
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Elaphe carinata	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species disturbance, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Named species	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Thalasseus bergii	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance
Pollution	Industrial & military effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Indirect ecosystem effects
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Food - human	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Chinese Crested Tern Thalasseus bernsteini. Downloaded from https://datazone.birdlife.org/species/factsheet/chinese-crested-tern-thalasseus-bernsteini on 18/12/2024.
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 18/12/2024.