• 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., 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
-	-	-

Red List history

Year	Category	Criteria
2022	Least Concern
2017	Data Deficient
2016	Data Deficient
2012	Data Deficient
2008	Data Deficient
2004	Data Deficient
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	46,100 km2	medium
Extent of Occurrence (non-breeding)	798,000 km2	medium

	Estimate	Data quality	Derivation	Year of estimate
Population size	1500-4999 mature individuals	poor	suspected	2020
Population trend	unknown	-	-	-
Generation length	3.1 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The species has been described as relatively common at sites where it is known to breed (Timmins et al. 2009, Ayé et al. 2010, Kvartalnov et al. 2013). Recent information from the Wakhan District of Northeastern Afghanistan suggests that the species is found across 450 hectares of suitable habitat that is dispersed across many patches (S. Ostrowski via L. Svensson in litt. 2020). All patches were thought to be occupied, with c. 2-4 breeding pairs per hectare, roughly equating to 900-1,800 breeding pairs across the suitable range in Wakhan (S. Ostrowski via L. Svensson in litt. 2020), converted here to 1,800-3,600 mature individuals. Similarly the species is common in suitable breeding habitat in the Panj, Ghund and lower Pamir valley in Tajikistan (Kvartalnov et al. 2013), suggesting that overall the population is likely to be at least moderately large and likely much greater than 1,000 mature individuals. It is however unknown if the overall breeding range contains similarly high levels of species density (the total breeding range equates to approximately 18,000 km²). Upper limits to the population size are highly uncertain. On a precautionary basis, it is suspected that there are fewer than 10,000 mature individuals, given the relatively restricted breeding area and that only a small fraction of this is suitable habitat. Should further areas with similar densities to those described above exist the true population could well be higher still. Provisionally though the population is placed in a band of 1,000 to 10,000 mature individuals.
Genetic sampling appears to indicate evidence of past barriers within the population but that these have been eroded in relatively recent times, suggesting that there is a level of dispersal sufficient to consider that there is a single population (Svensson et al. 2008, Koblik et al. 2011).
The current population trend is uncertain, but there appear few significant threats to the breeding habitat.

Trend justification: The current trend is unknown, although genetic analysis has demonstrated considerable intra-specific variation from across the range, suggesting declining or stable populations (Svensson et al. 2008).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Afghanistan	extant	native		yes
Bangladesh	extant	native			yes
China (mainland)	presence uncertain	native
India	extant	native			yes	yes
Kazakhstan	extant	native
Kyrgyzstan	presence uncertain	native
Myanmar	extant	native			yes
Pakistan	extant	native
Tajikistan	extant	native		yes
Thailand	extant	native			yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Aquatic & Marine	Artificial/Aquatic - Ponds (below 8ha)	suitable	non-breeding
Artificial/Aquatic & Marine	Artificial/Aquatic - Wastewater Treatment Areas	suitable	passage
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	possible	non-breeding
Grassland	Subtropical/Tropical Seasonally Wet/Flooded	suitable	non-breeding
Shrubland	Mediterranean-type Shrubby Vegetation	major	breeding
Shrubland	Subtropical/Tropical Dry	major	breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	non-breeding
Altitude	900 - 3200 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Livestock farming & ranching - Small-holder grazing, ranching or farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Marine & freshwater aquaculture - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Causing/Could cause fluctuations		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		No decline		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Food - human	subsistence

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Recommended citation
BirdLife International (2024) Species factsheet: Large-billed Reed-warbler Acrocephalus orinus. Downloaded from https://datazone.birdlife.org/species/factsheet/large-billed-reed-warbler-acrocephalus-orinus on 22/12/2024.
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 22/12/2024.