CR
Rimatara Reed-warbler Acrocephalus rimitarae



Taxonomy

Taxonomic note

Acrocephalus rimitarae (del Hoyo and Collar 2016) was previously listed as A. rimatarae.

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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
B1ab(iii,v) B1ab(iii,v); C2a(ii) B1ab(iii,v); C2a(i,ii); D1+2

Red List history
Year Category Criteria
2018 Critically Endangered B1ab(iii,v)
2017 Critically Endangered B1ab(iii,v)
2016 Vulnerable D1+2
2012 Vulnerable D1+2
2008 Vulnerable D1; D2
2006 Vulnerable
2004 Vulnerable
2000 Vulnerable
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 7 medium
Number of locations 1 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 600-2600 poor estimated 2017
Population trend Decreasing poor estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 1 - - -
Largest subpopulations 100 - - -
Generation length (yrs) 4.4 - - -

Population justification: Various population estimates have been made which differ widely depending on methods used. Point count observations in 2002 gave a population estimate of 5,000 birds (Blanvillain 2002). Territory mapping techniques used by Thibault and Cibois (2006a) gave estimates of 1,777-2,567 breeding birds in 2004 (roughly 2,665-3,850 individuals), and transects gave estimates of 740 (Raust and Sanford 2002), 675 (Gouini 2004) and 670 (Albar et al. 2009), though applying a correction to account for differences in methodology would lead to higher estimates from these (Blanvillain et al. 2015). The most recent estimate generated is 1,780-2,781 individuals (C. Blanvillain in litt. 2017). Taking into account corrections (see Blanvillain et al. 2015), the range of estimates fall into the range of approximately 900-3,850 individuals, which roughly equates to 600-2,600 mature individuals (G. Dutson in litt. 2016).

Trend justification: Given the threats the species may be facing, and the continuing degradation of its habitat, it is considered to be undergoing a slow ongoing decline (C. Blanvillain in litt. 2016 per G. Dutson in litt. 2016). Population estimates made using similar methodologies in 2006 and 2017 suggest a reduction (Thibault and Cibois 2006a; C. Blanvillain in litt. 2017).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
French Polynesia N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
French Polynesia Rimatara

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands major resident
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Acridotheres tristis Timing Scope Severity Impact
Future Majority (50-90%) Rapid Declines Low Impact: 5
Stresses
Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus exulans Timing Scope Severity Impact
Ongoing Whole (>90%) Negligible declines Medium Impact: 6
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus norvegicus Timing Scope Severity Impact
Ongoing Whole (>90%) Negligible declines Medium Impact: 6
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus rattus Timing Scope Severity Impact
Future Whole (>90%) Rapid Declines Medium Impact: 6
Stresses
Reduced reproductive success
Residential & commercial development Tourism & recreation areas Timing Scope Severity Impact
Ongoing Minority (<50%) Rapid Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2020) Species factsheet: Acrocephalus rimitarae. Downloaded from http://www.birdlife.org on 24/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/09/2020.