• 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
-	-	C2a(i)

Red List history

Year	Category	Criteria
2023	Vulnerable	C2a(i)
2016	Vulnerable	C2a(i)
2012	Vulnerable	C2a(i)
2008	Vulnerable	C2a(i)
2004	Vulnerable
2000	Endangered
1996	Vulnerable
1994	Vulnerable
1988	Near Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	104,000 km2	medium
Area of Occupancy (breeding/resident)	9,952 km2
Number of locations	15-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2500-9999 mature individuals	medium	estimated	2022
Population trend	decreasing	poor	inferred	2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	2.68 years	-	-	-
Number of subpopulations	15-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: Based on extensive surveys across the range, it is estimated that the population numbers less than 10,000 mature individuals (ICMBio 2018). It is here placed in the band 2,500-9,999 mature individuals.
The species is restricted to isolated forest fragments and observational records are scattered across the range (ICMBio 2018, eBird 2022). It appears sensitive to habitat disturbance and avoids early successional growth and therefore is likely unable to disperse between occupied forest patches. Based on its disjunct range, it is therefore assumed that it forms at least 15 separate, small subpopulations.

Trend justification: There are no data on the population trend. However, the species has become locally extinct in recent years in several areas (ICMBio 2018). It is estimated that the total area of occupancy declined by 25% over 15 years (ICMBio 2018). As the species is rare and confined to small, isolated subpopulations in disjunct patches of forest, it is inferred that the population declines are continuing on the basis of reductions in forest cover and increasing fragmentation between populations.
Within the range, 8% of tree cover is lost over ten years (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). As patches of suitable habitat are scattered and isolated, population declines may exceed the rate of tree cover loss due to the additional impact of habitat fragmentation. Tentatively, population declines are here placed in the band 10-19% over ten years. This value is confirmed by the reported declines in the area of occupancy, which correspond to 17% over ten years.

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

Country/Territory	IBA Name
Brazil	Estação Veracruz
Brazil	Ilhéus / Itabuna
Brazil	Parque Nacional do Pau Brasil / Trancoso
Brazil	Serras das Lontras e do Javi

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	resident
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Altitude	0 - 910 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		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder 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
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Band-tailed Antwren Myrmotherula urosticta. Downloaded from https://datazone.birdlife.org/species/factsheet/band-tailed-antwren-myrmotherula-urosticta 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.