• 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.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	C2a(ii)

Red List history

Year	Category	Criteria
2016	Vulnerable	C2a(ii)
2012	Vulnerable	C2a(ii)
2008	Vulnerable	C1; C2a(ii)
2007	Vulnerable
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Lower Risk/Least Concern

Migratory status	full migrant	Forest dependency	medium
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	133,000 km2	medium
Extent of Occurrence (non-breeding)	2,260,000 km2	medium
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2500-9999 mature individuals	poor	estimated	2000
Population trend	decreasing	poor	suspected	2011-2022
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	3.6 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The global population is estimated to number a few thousand based on an analysis by BirdLife International (2001). It is estimated to number 2,500-9,999 mature individuals, equating to 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals. National population sizes have been estimated at c.50 individuals on migration and c.50 wintering individuals in Taiwan, and c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Japan.

Trend justification: A moderate and on-going population decline is suspected owing to habitat change within the breeding grounds, as well as the low number of recent records.

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

Country/Territory	IBA Name
Japan	Aogashima island
Japan	Hachijojima island
Japan	Kozushima island
Japan	Mikurajima island
Japan	Miyakejima island
Japan	Niijima and Shikinejima Islands
Japan	Oshima island
Japan	Tokara islands
Japan	Toshima island
Philippines	Mariveles mountains

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	non-breeding
Forest	Subtropical/Tropical Dry	major	breeding
Forest	Subtropical/Tropical Moist Lowland	major	non-breeding
Forest	Subtropical/Tropical Moist Lowland	major	breeding
Shrubland	Subtropical/Tropical Moist	suitable	breeding
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Pollution	Agricultural & forestry effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Reduced reproductive success, Species mortality
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Slow, Significant Declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Roads & railroads	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: Ijima's Leaf-warbler Phylloscopus ijimae. Downloaded from https://datazone.birdlife.org/species/factsheet/ijimas-leaf-warbler-phylloscopus-ijimae 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.