VU
Pirre Warbler Basileuterus ignotus



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: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - D1

Red List history
Year Category Criteria
2021 Vulnerable D1
2016 Vulnerable D2
2012 Vulnerable D2
2008 Vulnerable D2
2007 Vulnerable
2004 Vulnerable
2000 Vulnerable
1994 Lower Risk/Near Threatened
1988 Near Threatened
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type continent
Average mass 11 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 1,600 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 650-6500 mature individuals poor estimated 2021
Population trend stable poor suspected -
Generation length 2.9 years - - -
Number of subpopulations 2 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The population size has not been quantified directly. Based on population density estimates of two closely related species with similar body size, similar habitat requirements and a similar altitudinal range, Myiothlypis nigrocristata and Myiothlypis luteoviridis, of 10-100 individuals/km2 in Andean forests in Ecuador (per Renjifo et al. 2016), and assuming that this species occurs at a similar density throughout suitable habitat (which is estimated at up to 100 km2; Wege 1996), the total population is estimated at 1,000-10,000 individuals. This roughly equates to 650-6,500 mature individuals.

The subpopulation structure has not been formally assessed, but it is tentatively assumed that there are two disjunct subpopulations on Cerro Pirre and on Cerro Tacarcuna. Under the assumption that the total population size is closer to the lower end of the estimate, both subpopulations may be very small.

Trend justification: The population is currently suspected to be stable in the absence of evidence for any declines or substantial threats.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Colombia extant native yes
Panama extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Panama Darién National Park

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 1200 - 1650 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
Future Majority (50-90%) Slow, Significant Declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Slow, Significant Declines Low Impact: 5
Stresses
Indirect ecosystem effects, Ecosystem degradation
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines Low Impact: 3
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines Low Impact: 3
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2024) Species factsheet: Pirre Warbler Basileuterus ignotus. Downloaded from https://datazone.birdlife.org/species/factsheet/pirre-warbler-basileuterus-ignotus on 23/12/2024.
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 23/12/2024.