NT
Seychelles Warbler Acrocephalus sechellensis



Taxonomy

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
- - -

Red List history
Year Category Criteria
2021 Near Threatened B1a+2a
2016 Near Threatened D2
2015 Near Threatened D2
2012 Vulnerable D2
2008 Vulnerable D2
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 1,200 km2 medium
Area of Occupancy (breeding/resident) 40 km2
Number of locations 5 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 3000 mature individuals good estimated 2014
Population trend increasing good estimated -
Generation length 7.5 years - - -
Number of subpopulations 5 - - -

Population justification: In 2007, the population probably numbered over 2,500 birds (G. Rocamora in litt. 2007), roughly equivalent to a minimum of 1,700 mature individuals. Since 2007 the population has increased strongly with c. 2,800 adults in 2014 (N. Shah in litt. 2014) and c. 3,000 adults in August 2016 (D. S. Richardson in litt. 2016).

Trend justification: A population of 58 birds translocated to Denis in May and June 2004 had increased to 75 by August 2005 (Richardson et al. 2006), whilst the number of birds on Cousin increased from 323 in 1997 (Komdeur et al. 1997) to 371 in September 2005 (Richardson et al. 2006). The species is increasing as a result of habitat management and translocations, with the population recently estimated to be c. 3,000 adults (D. S. Richardson in litt. 2015).


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Seychelles extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Seychelles Aride Island Special Reserve
Seychelles Cousin Island Special Reserve
Seychelles Cousine island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Mangrove Vegetation Above High Tide Level suitable resident
Forest Subtropical/Tropical Swamp suitable resident
Shrubland Subtropical/Tropical Moist major resident
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Past, Unlikely to Return Majority (50-90%) No decline Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Acridotheres tristis Timing Scope Severity Impact
Ongoing Majority (50-90%) No decline Low Impact: 5
Stresses
Skewed sex ratios, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Plasmodium relictum Timing Scope Severity Impact
Ongoing Majority (50-90%) No decline Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Foudia sechellarum Timing Scope Severity Impact
Ongoing Majority (50-90%) No decline Low Impact: 5
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Named species Timing Scope Severity Impact
Ongoing Majority (50-90%) No decline Low Impact: 5
Stresses
Reduced reproductive success

Recommended citation
BirdLife International (2024) Species factsheet: Acrocephalus sechellensis. Downloaded from https://datazone.birdlife.org/species/factsheet/seychelles-warbler-acrocephalus-sechellensis on 03/03/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 03/03/2024.