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

Taxonomic note

Acrocephalus caffer, A. musae and A. longirostris (del Hoyo and Collar 2016) were previously lumped as A. caffer following Sibley & Monroe (1990, 1993).

Taxonomic source(s)
Cibois, A.; Thibault, J.-C.; Pasquet, E. 2008. Systematics of the extinct reed warblers Acrocephalus of the Society Islands of eastern Polynesia. Ibis 150(2): 365-376.
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
D	D	D1+2

Red List history

Year	Category	Criteria
2019	Critically Endangered	D
2016	Critically Endangered	D
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	204 km2	medium
Area of Occupancy (breeding/resident)	204 km2
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1-49 mature individuals	poor	suspected	2016
Population trend	unknown	poor	-	1998-2008
Generation length	4.4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The lack of any confirmed recent reports suggests that the population size is likely very low (probably less than 50 mature individuals).

Trend justification: There is no evidence to indicate that the species's area of habitat is declining, but the lack of recent confirmed records and lack of knowledge about the reasons for the species's past decline prevent an assessment of the current population trend.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
French Polynesia	extant	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Plantations	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Shrubland	Subtropical/Tropical Moist	major	resident
Altitude	300 - 600 m	Occasional altitudinal limits	(max) 1700 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Marine & freshwater aquaculture - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Gathering terrestrial plants - Unintentional effects (species is not the target)	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species disturbance, Ecosystem degradation, Reduced reproductive success
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Ecosystem degradation, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Acridotheres tristis	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Miconia calvescens	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Pycnonotus cafer	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion, Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Moorea Reed-warbler Acrocephalus longirostris. Downloaded from https://datazone.birdlife.org/species/factsheet/moorea-reed-warbler-acrocephalus-longirostris on 20/12/2024.
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 20/12/2024.