• 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
2024	Least Concern
2016	Least Concern
2013	Least Concern
2012	Least Concern
2008	Near Threatened	B1a+b(i,ii,iii,v)
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	186,000 km2	medium
Number of locations	24	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	46000-54000 mature individuals	poor	estimated	2003
Population trend	decreasing	poor	suspected	1998-2008
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-25%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Generation length	2.66 years	-	-	-
Number of subpopulations	2-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: Herzog et al. (2008) estimated the population to be 70,000-80,000 individuals. This species is considered to have a high dependency on forest habitat, and tree cover is estimated to have declined by 3.8% within its mapped range over the past 10 years (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). It is therefore tentatively suspected that this rate of cover loss may have led to a decline of between 1-19% in the species' population size over the same time frame, with a best estimate of reduction being less than 5%.

Trend justification:   .

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

Country/Territory	IBA Name
Bolivia	Serranía Bella Vista
Bolivia	Yungas Inferiores de Amboró
Bolivia	Yungas Inferiores de Carrasco
Bolivia	Yungas Inferiores de Isiboro-Sécure / Altamachi
Bolivia	Yungas Inferiores de Madidi
Bolivia	Yungas Inferiores de Pilón Lajas
Bolivia	Yungas Superiores de Apolobamba
Bolivia	Yungas Superiores de Mosetenes y Cocapata

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	330 - 1650 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
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
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Unknown		Unknown
		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

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Recommended citation
BirdLife International (2024) Species factsheet: Ashy Antwren Myrmotherula grisea. Downloaded from https://datazone.birdlife.org/species/factsheet/ashy-antwren-myrmotherula-grisea 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.