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

Taxonomic source(s)
Brooks, T. 2000. Extinct species. In: BirdLife International (ed.), Threatened Birds of the World, pp. 701-708. Lynx Edicions and BirdLife International, Barcelona and Cambridge, U.K.
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

Red List history

Year	Category	Criteria
2024	Extinct
2016	Extinct
2012	Extinct
2008	Extinct
2004	Extinct
2000	Extinct
1996	Extinct
1994	Extinct
1988	Threatened

Migratory status	not a migrant	Forest dependency	low
Land-mass type		Average mass	19 g

	Estimate	Data quality
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	0 mature individuals	good	estimated	-
Population trend		-	-	-
Generation length	3 years	-	-	-

Population justification: None remain.

Trend justification: Little is known about the exact cause of this species' extinction. The species appears to have always had a severely restricted geographical range (Prŷs-Jones 1979 in Hume 2017,  Safford and Hawkins 2013) and consequentially has likely always occurred in low densities. Two individuals were collected in 1967 (Benson and Penny 1968), and another in 1974, with none seen until five were observed through surveys in 1974-76 (Prŷs-Jones 1979). Only two males were known definitively as of February 1977, with only one by October 1983 (Collar and Stuart 1985), which was the last record of the species (Safford and Hawkins 2013). The disappearance of the species was very likely caused by cats and Rattus rattus (Black Rats) which were present on middle island (Hume 2017). A speculated secondary factor was the presence of Aldabrachelys gigantea (Aldabra Giant Tortoise), which generally do not occur in the dense scrub that Nesillas aldabrana occupied (Prŷs-Jones 1979,  Safford and Hawkins 2013). However, as introduced goats altered habitat through grazing, the tortoises may have been allowed access to these habitats, and began grazing on leaf litter which N. aldabrana required for foraging (Prŷs-Jones 1979,  Safford and Hawkins 2013). Regardless, it appears this poorly known species became extinct sometime in the early 1980s.

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

Country/Territory	IBA Name
Seychelles	Aldabra Special Reserve

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Shrubland	Subtropical/Tropical Moist	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Capra hircus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Species disturbance, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Geochelone gigantea	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Aldabra Brush-warbler Nesillas aldabrana. Downloaded from https://datazone.birdlife.org/species/factsheet/aldabra-brush-warbler-nesillas-aldabrana 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.