VU
Bioko Speirops Zosterops brunneus



Taxonomy

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.

IUCN Red list criteria met and history
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
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 70 medium
Number of locations 1 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 6000-15000 poor estimated 2000
Population trend Stable poor suspected -
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 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 4.4 - - -

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 distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Equatorial Guinea N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Equatorial Guinea Basilé Peak National Park

Habitats & altitude
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

Threats & impact
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

Recommended citation
BirdLife International (2022) Species factsheet: Zosterops brunneus. Downloaded from http://www.birdlife.org on 28/09/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/09/2022.