• 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
2023	Least Concern
2016	Near Threatened	A3c
2012	Near Threatened	A3c
2009	Least Concern
2008	Least Concern
2004	Least Concern
2000	Lower Risk/Least Concern
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	28 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,600,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	suspected	2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Generation length	3.2 years	-	-	-

Population justification: The global population size has not been quantified, but this species is described as uncommon to fairly common (Stotz et al. 1996, Schulenberg and Rosenberg 2020).

Trend justification: There are no data on the population trend, but declines are suspected on the basis of accelerating rates of deforestation along large rivers in the Amazon basin.
Within the range, 5% of tree cover is lost over ten years (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Even though the species appears to show some tolerance of low levels of human disturbance (Schulenberg and Rosenberg 2020), the population may be disproportionately affected as its riverine habitat is easily accessible and thus highly susceptible to forest loss and degradation. Precautionarily, population declines are therefore here placed in the band 1-19% over ten years.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Swamp	major	resident
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	resident
Altitude	0 - 400 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%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Other impacts	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Natural system modifications	Dams & water management/use - Large dams	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Castelnau's Antshrike Thamnophilus cryptoleucus. Downloaded from https://datazone.birdlife.org/species/factsheet/castelnaus-antshrike-thamnophilus-cryptoleucus on 24/11/2024.
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 24/11/2024.