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

Taxonomic note
Phylloscopus presbytes has been split into Timor Leaf-warbler P. presbytes and Rote Leaf-warbler P. rotiensis after Ng et al. (2018). 

The previously undescribed taxon, in comparison with P. presbytes, differs by its; greater bill length, possibly related to a bark-gleaning habit unusual in leaf-warblers (16.3 [n=1] vs 13.4 [n=2] (allow 3); much stronger pale yellow median crown-stripe (2); wholly yellow-orange vs mostly dark lower mandible (1); richer yellow underparts, supercilium and ear-coverts (2); brighter olive-brown upperparts (ns[1]).

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2019. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 4. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v4_Dec19.zip.
Ng, N. S., Prawiradilaga, D. M., Ng, E. Y., Ashari, H., Trainor, C., Verbelen, P., & Rheindt, F. E. 2018. A striking new species of leaf warbler from the Lesser Sundas as uncovered through morphology and genomics. Scientific reports 8(1): 15646.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Near Threatened	B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v); C2a(ii)
2016	Not Recognised
2012	Not Recognised
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		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,900 km2
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2500-9999 mature individuals	poor	suspected	2019
Population trend	decreasing	-	suspected	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population size of this species has not been quantified. However, a preliminary population estimate can be derived from a congener, the Island Leaf-warbler (Phylloscopus poliocephalus), which occurs from the Indonesian Archipelago through Papua New Guinea to the Solomon Islands. This species occurs at a density of c. 180 individuals/km² in intact forest (Marsden 1998). Only an area of 244 km² offer suitable forested habitat for Rote Leaf-warbler throughout its range (Ng et al. 2018). Assuming that Rote Leaf-warbler occurs at a similar density throughout suitable habitat, and that only about 20% of suitable habitat is occupied, the population may number c. 8,800 individuals, which roughly equates to 5,900 mature individuals. As this estimate is highly preliminary and requires confirmation, the species is tentatively placed in the band 2,500-9,999 mature individuals.

Trend justification: The population trend has not been quantified, but the species is threatened by habitat loss and deforestation. Although the species is currently predominantly found on the Tapuafu Peninsula, where large areas of intact forest persist (Ng et al. 2018, eBird 2019), the species's restricted range and specific habitat requirements make it vulnerable to habitat degradation and loss. As a result, and given the degree of disturbance and fragmentation already within its range, the species is precautionarily suggested to be undergoing a slow decline (Ng et al. 2018).

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

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 Dry	major	resident
Altitude	0 - 420 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Shifting agriculture	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, Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Rote Leaf-warbler Phylloscopus rotiensis. Downloaded from https://datazone.birdlife.org/species/factsheet/rote-leaf-warbler-phylloscopus-rotiensis 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.