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

Taxonomic note
Zosterops brunneus (del Hoyo and Collar 2016) was previously listed as Speirops brunneus.

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.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	D2

Red List history

Year	Category	Criteria
2016	Vulnerable	D2
2012	Vulnerable	D2
2008	Vulnerable	D2
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

Migratory status	not a migrant	Forest dependency	medium
Land-mass type	shelf island	Average mass	16 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	70 km2	medium
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	6000-15000 mature individuals	poor	estimated	2000
Population trend	stable	poor	suspected	1998-2008
Generation length	4.4 years	-	-	-

Population justification: The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification: The species's population is suspected to be stable because access to its habitat is restricted and no immediate threats are known.

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

Country/Territory	IBA Name
Equatorial Guinea	Basilé Peak National Park

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Montane	major	resident
Shrubland	Subtropical/Tropical High Altitude	major	resident
Altitude	1900 - 2800 m	Occasional altitudinal limits	(max) 3000 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Natural system modifications	Fire & fire suppression - Trend Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Bioko Speirops Zosterops brunneus. Downloaded from https://datazone.birdlife.org/species/factsheet/bioko-speirops-zosterops-brunneus 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.