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

Taxonomic source(s)
Alström, P.; Olsson, U.; Round, P. D. 1991. The taxonomic status of Acrocephalus agricola tangorum. Forktail: 3-13.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	C2a(ii)

Red List history

Year	Category	Criteria
2016	Vulnerable	C2a(ii)
2012	Vulnerable	C2a(ii)
2008	Vulnerable	C2a(ii)
2007	Vulnerable
2004	Vulnerable
2000	Vulnerable
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	757,000 km2	medium
Extent of Occurrence (non-breeding)	303,000 km2	medium
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2500-9999 mature individuals	poor	estimated	2000
Population trend	decreasing	poor	suspected	2010-2023
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	4.4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The global population estimate of 2,500-9,999 mature individuals is based on a detailed analysis of records by BirdLife International (2001), where it was concluded that the species must have a fairly small world population (i.e. fewer than 10,000).  This estimate equates to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.  All individuals are considered to belong to a single population on the basis of the migratory nature of the species and the lack of clear division within the known breeding range of the species.

Trend justification: Although perhaps more common than it was thought to be in the 1990s, this species is suspected to be continuing to decline at a moderate rate, owing to the conversion of many natural systems.  While it may be tolerant of some modified habitats, the species is unlikely to cope with heavily intensified agricultural and urban environments.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Cambodia	extant	native			yes
China (mainland)	extant	native		yes
Hong Kong (China)	extant	vagrant
Laos	extant	native			yes
Malaysia	extant	native			yes
Myanmar	extant	native
Russia	extant	native		yes
Russia (Asian)	extant	native		yes
South Korea	extant	vagrant
Thailand	extant	native			yes
Vietnam	extant	native				yes

Country/Territory	IBA Name
Cambodia	Chhep
Cambodia	Stung / Chi Kreng / Kampong Svay
Cambodia	Stung Sen / Santuk / Baray
Cambodia	Veal Srongae
China (mainland)	Mudanfeng Nature Reserve
Laos	Dong Khanthung
Thailand	Khao Sam Roi Yot
Thailand	Lower Central Basin

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Subtropical/Tropical Seasonally Wet/Flooded	suitable	non-breeding
Grassland	Subtropical/Tropical Seasonally Wet/Flooded	suitable	non-breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	major	breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	major	breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	suitable	breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	suitable	breeding
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	suitable	breeding
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	suitable	breeding
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Marine & freshwater aquaculture - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Marine & freshwater aquaculture - Subsistence/artisinal aquaculture	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Wood & pulp plantations - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Natural system modifications	Dams & water management/use - Abstraction of surface water (agricultural use)	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Natural system modifications	Dams & water management/use - Small dams	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: White-browed Reed-warbler Acrocephalus tangorum. Downloaded from https://datazone.birdlife.org/species/factsheet/white-browed-reed-warbler-acrocephalus-tangorum on 23/11/2024.
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 23/11/2024.