NT
Choco Vireo Vireo masteri



Taxonomy

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.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2019 Near Threatened B2b(i,ii,iii)
2016 Endangered B1ab(i,ii,iii,v)
2012 Endangered B1ab(i,ii,iii,v)
2008 Endangered B1a+b(i,ii,iii,v)
2004 Endangered
2000 Endangered
1994 Vulnerable
1988 Not Recognised
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 34,500 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 14200-17000 poor estimated 2007
Population trend Decreasing poor 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) 10-19 - - -
Decline (10 years/3 generation past and future) 10-19 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations - - -
Generation length (yrs) 4.2 - - -

Population justification: Its potential global population was estimated to be as high as 78,000 ±7,000 mature individuals based on estimates of the area of forest cover within its range. However, the two occupied areas in Colombia are 520 km apart. Although the species may occur in appropriate habitat in between these sites (Salaman and Stiles 1996, P. Salaman in litt. 1999, 2000, Renjifo et al. 2002, P. Salaman in litt. 2003), searches of the intervening area have completely failed to find the species, despite excellent knowledge of its vocalizations and its reliable response to playback (P. Salaman in litt. 1999, 2000, 2003). Therefore, a precautionary population size estimate was made of 15,600 ±1,400 mature individuals based upon a figure of 20% occupancy within the Extent of Occurrence (Jahn et al. 2007). The total population is estimated to number 20,000-25,000 individuals, based on population density data from Ecuador extrapolated over the species's known range. Population size is thought to be declining owing to loss and fragmentation of its habitat.

Trend justification: The species is thought to be in decline, but the rate of decline has not been assessed directly. A recent analysis of the deforestation rate in the Chocó area of northwestern Ecuador found that on average, 61% of the original forest cover has been lost (Finer and Mamani 2019, M. Schaefer in litt. 2019). Forest loss has been most severe in the lowlands, with 68% of the original forest cover gone. In mid and upper elevations, where Chocó Vireo is found, about 50% of the original forest cover has disappeared (Finer and Mamani 2019, M. Schaefer in litt. 2019). Between 2000 and 2018, deforestation rates in the Ecuadorian Chocó amounted to 20% (Finer and Mamani 2019, M. Schaefer in litt. 2019). There are no detailed data available for the rate of forest loss in the Colombian part of the range. While forest cover in western Colombia was stable overall, or even increasing between 2001 and 2010 (Sanchez-Cuervo and Aide 2013), it is feared that deforestation rates have increased since (M. Schaefer in litt. 2019). Therefore precautionarily, it is assumed that the overall forest cover throughout the range has declined by 20% between 2000 and 2018. Assuming furthermore that deforestation continues at the same rate and that the population decline is proportional to the deforestation rate, it is suspected that Choco Vireo is declining at 14.5% over three generations (12.6 years). To account for local differences in the rate of population decline, it is here placed in the band 10-19% over three generations.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Colombia Alto de Pisones
Colombia Reserva Natural El Pangán
Colombia Reserva Natural Río Ñambí
Ecuador Mashpi-Pachijal
Ecuador Los Bancos - Milpe
Ecuador Territorio Étnico Awá y alrededores

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Subtropical/Tropical Heavily Degraded Former Forest suitable resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 800 - 1600 m Occasional altitudinal limits  

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
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Small-holder grazing, ranching or farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2020) Species factsheet: Vireo masteri. Downloaded from http://www.birdlife.org on 06/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/08/2020.