Pale-throated Barbet Gymnobucco vernayi


Taxonomic note

Gymnobucco calvus and G. vernayi (del Hoyo and Collar 2014) were previously lumped as G. calvus following Sibley and Monroe (1990, 1993).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - C2a(ii)

Red List history
Year Category Criteria
2019 Vulnerable C2a(ii)
2016 Least Concern
2014 Least Concern
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 38,600 medium
Number of locations 11-15 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 2500-9999 poor inferred 2019
Population trend Decreasing inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 1-9 - - -
Decline (10 years/3 generation past and future) 1-9 - - -
Number of subpopulations 1 - - -
Largest subpopulations 100 - - -
Generation length (yrs) 8.5 - - -

Population justification: Current population size calculated based on local observations (M. Mills in litt. 2019) and an expected density of <c.1.3 mature individuals/km2. True figure could be considerably lower and a more robust population estimate is needed.

Trend justification: The population is suspected to be in decline owing to loss of suitable nesting and roosting trees (del Hoyo et al. 2002). Extrapolating data from Tracewski et al. (2016) suggests that the area of forest within the species’s range is declining at a rate of approximately 8.6% over three generations (25.5 years). Therefore, if we assume that population trends are proportional to habitat trends, we can suspect that the population is declining at a rate of 8.6% over three generations. here placed in the band 1-9%. Survey work has shown the species to have disappeared from or declined at some locations (M. Mills in litt. 2018), which further supports the view that the species is in decline.

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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Angola Chongoroi
Angola Gabela
Angola Mombolo (Missão da Namba)
Angola Mount Moco

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Plantations suitable resident
Artificial/Terrestrial Rural Gardens suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane suitable resident
Savanna Dry suitable resident
Altitude 0 - 1820 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Wood & pulp plantations - Agro-industry plantations Timing Scope Severity Impact
Ongoing Unknown Slow, Significant Declines Unknown
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Intentional use: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Unknown Slow, Significant Declines Unknown
Ecosystem degradation
Biological resource use Logging & wood harvesting - Motivation Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Unknown Unknown Unknown
Ecosystem degradation

Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2021) Species factsheet: Gymnobucco vernayi. Downloaded from on 25/01/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 25/01/2021.