• 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
-	-	-

Red List history

Year	Category	Criteria
2017	Least Concern
2016	Near Threatened	B1ab(i,ii,iii,v)
2012	Near Threatened	B1ab(i,ii,iii,v)
2008	Near Threatened	B1a+b(i,ii,iii,v)
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	65,300 km2	medium
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	suspected	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-25%	-	-	-
Generation length	4.8 years	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population size of this species has not been quantified, but it is described as locally common in general, being rare and local in Ecuador but locally fairly common in Peru.

Trend justification: This species is suspected to lose 3.5% of suitable habitat within its distribution over three generations (14 years) based on a model of Amazonian deforestation (Soares-Filho et al. 2006, Bird et al. 2011). Although susceptible to fragmentation and/or edge effects, it is therefore suspected to decline by <25% over three generations.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Ecuador	extant	native	yes
Peru	extant	native	yes

Country/Territory	IBA Name
Ecuador	Territorio Achuar
Peru	Cuenca Río Nanay
Peru	Morona

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Savanna	Dry	suitable	resident
Altitude	0 - 200 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
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid 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
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Ancient Antwren Herpsilochmus gentryi. Downloaded from https://datazone.birdlife.org/species/factsheet/ancient-antwren-herpsilochmus-gentryi 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.