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

Taxonomic note
Rhizothera longirostris and R. dulitensis (del Hoyo and Collar 2014) were previously lumped as R. longirostris following Sibley and Monroe (1990, 1993).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Data Deficient
2016	Vulnerable	C2a(i)
2014	Vulnerable	C2a(i)
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	unknown
Land-mass type		Average mass	-

	Estimate	Data quality
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	poor	unknown	-
Population trend	unknown	poor	-	-
Generation length	6.19 years	-	-	-

Population justification: Entirely unknown. Berryman and Boakes (2023) determined that the species has not been seen since 1902 (contra Orenstein et al. 2010, Eaton et al. 2021), despite moderate effort at localities from which was collected and/or is likely to occur; consequently, its population may be small. However, the same authors also identified that, if like R. longirostris, it is extremely elusive, it could simply have very low detectability and/or have strict habitat requirements that have not yet been identified. Given that a large area of suitable habitat remains, its population may, in fact, be very large. In the absence of even cursory data, qualitative and quantitative estimations of this species' abundance are not possible.

Trend justification: With no confirmed sightings for more than 120 years (see Berryman and Boakes 2023), there are no available data on population trends. Plausible threats for this species include logging and hunting, however whether these are causing ongoing declines is totally unknown.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	possible	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	900 - 1200 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		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Dulit Partridge Rhizothera dulitensis. Downloaded from https://datazone.birdlife.org/species/factsheet/dulit-partridge-rhizothera-dulitensis on 26/12/2024.
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 26/12/2024.