• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

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

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,600 km2	medium
Severely fragmented?	no	-

	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	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Colombia	extant	native	yes
Panama	extant	native	yes

Country/Territory	IBA Name
Panama	Darién National Park

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	1200 - 1650 m	Occasional altitudinal limits

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

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Recommended citation
BirdLife International (2024) Species factsheet: Pirre Warbler Basileuterus ignotus. Downloaded from https://datazone.birdlife.org/species/factsheet/pirre-warbler-basileuterus-ignotus on 23/11/2024.
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 23/11/2024.