• 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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Near Threatened	C2a(i)
2016	Near Threatened	B1ab(ii,iii,v)
2015	Near Threatened	B1ab(ii,iii,v)
2012	Vulnerable	B1ab(ii,iii,v)
2010	Vulnerable	B1a+b(ii,iii,v)
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	47,000 km2	medium
Number of locations	11-15	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	suspected	-
Generation length	5.5 years	-	-	-

Population justification: The global population size has not been quantified. It has been described as uncommon, although it may be more common than suggested by field observations owing to its secretive habits (del Hoyo et al. 2007). It is likely that the species numbers below 10,000 mature individuals and given the separation of suitable habitat the largest subpopulation may be as few as 1,000 mature individuals, assuming that this are separate subpopulations due to the likelihood that there is little regular interchange of individuals between the widely separate occupied areas.

Trend justification: There are no adequate data to quantify trends for this species, although it is suspected to be declining owing to habitat destruction (del Hoyo et al. 2007).

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Forest	Subtropical/Tropical Moist Montane	suitable	resident
Rocky areas (eg. inland cliffs, mountain peaks)		suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Altitude	0 - 1000 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: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Bicol Ground-warbler Robsonius sorsogonensis. Downloaded from https://datazone.birdlife.org/species/factsheet/bicol-ground-warbler-robsonius-sorsogonensis on 22/11/2024.
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 22/11/2024.