EN
Principe White-eye Zosterops ficedulinus



Taxonomy

Taxonomic note

Zosterops ficedulinus and Z. feae (del Hoyo and Collar 2016) were previously lumped as Z. ficedulinus following Dowsett & Forbes-Watson (1993) and Sibley & Monroe (1990, 1993).

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
- C2a(ii) C2a(i,ii); D1

Red List history
Year Category Criteria
2018 Endangered C2a(ii)
2016 Vulnerable D1
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 50 medium
Number of locations 11-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 250-999 poor estimated 2016
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 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 3.5 - - -

Population justification: The species was recently split from São Tomé White-eye (Zosterops feae) (del Hoyo and Collar 2016). The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals. The estimate is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. All individuals are thought to belong to the same subpopulation. Notably, given how restricted its range is, the population size could in fact be lower.

Trend justification: At the beginning of the 20th century, the species was considered quite common on the island (Hering et al. 2018). Declines were recorded from 1970 on, when primary and mature forests were increasingly cleared for agriculture and housing development. The species is likely intolerant of forest loss and degradation, and as such may be declining.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
São Tomé e Príncipe N Extant Yes

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

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 0 - 1600 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Scale Unknown/Unrecorded Timing Scope Severity Impact
Past, Unlikely to Return Majority (50-90%) Rapid Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Commercial & industrial areas Timing Scope Severity Impact
Future Minority (<50%) Negligible declines No/Negligible Impact: 2
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2021) Species factsheet: Zosterops ficedulinus. Downloaded from http://www.birdlife.org on 27/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/10/2021.