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

Taxonomic note

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. 2006. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.
SACC. 2006. 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
-	B1ab(i,ii,iii,v)	B1ab(i,ii,iii,v)

Red List history

Year	Category	Criteria
2016	Endangered	B1ab(i,ii,iii,v)
2012	Endangered	B1ab(i,ii,iii,v)
2008	Endangered	B1a+b(i,ii,iii,v)
2004	Endangered
2000	Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	2,700 km2	medium
Number of locations	7	-
Severely fragmented?	yes	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1500-7000 mature individuals	poor	estimated	2000
Population trend	decreasing	poor	suspected	1998-2008
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	3.9 years	-	-	-

Population justification: The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification: Although the species can still be found in patches of suitable habitat, ecosystem conversion and degradation are continuing unabated within the region, suggesting that populations are likely to be in decline, perhaps at a rate of 10-19% over ten years. Although it can occasionally be found in degraded forest, secondary forest and areas that have been previously cleared, it shows a strong preference for undisturbed humid forest with an intact understorey and is unlikely to persist successfully in the absence of primary forest (Sharpe 2008, C. J. Sharpe in litt. 2011).

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

Country/Territory	IBA Name
Venezuela	Parque Nacional El Guácharo
Venezuela	Zona Protectora Macizo Montañoso del Turimiquire

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	1200 - 2440 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Livestock farming & ranching - Agro-industry grazing, ranching or farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Grey-headed Warbler Basileuterus griseiceps. Downloaded from https://datazone.birdlife.org/species/factsheet/grey-headed-warbler-basileuterus-griseiceps 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.