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

Taxonomic note
Laniellus langbianis (del Hoyo and Collar 2016) was previously listed as Crocias langbianis.

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
-	B1ab(i,ii,iii,iv,v); C2a(ii)	B1ab(i,ii,iii,iv,v); C2a(ii); D2

Red List history

Year	Category	Criteria
2016	Endangered	B1ab(i,ii,iii,iv,v); C2a(ii)
2012	Endangered	B1ab(i,ii,iii,iv,v)
2008	Endangered	B1a+b(i,ii,iii,iv,v)
2004	Endangered
2000	Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	7,200	medium
Number of locations	2-5	-
Severely Fragmented		-

	Value	Data quality	Derivation	Year of estimate
No. of mature individuals	1500-7000	poor	estimated	2000
Population trend	Decreasing	poor	suspected	-
Decline (3 years/1 generation past)		-	-	-
Decline (5 years/1 generation past)		-	-	-
Decline (10 years/1 generation past)		-	-	-
Decline (10 years/3 generation future)	1-19	-	-	-
Decline (10 years/3 generation past and future)	1-19	-	-	-
Number of subpopulations	2-100	-	-	-
Percentage in largest subpopulation		-	-	-
Generation length (yrs)	4.4	-	-	-

Population justification: The population size is preliminarily estimated to fall into the band 2,500-9,999 individuals. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals. There is not sufficient evidence available to downlist the species.

Trend justification: Up-to-date information on population status is lacking, but various factors influencing habitats in the region are thought likely to be causing a population decline of 1-19% over ten years. The impact of these factors may increase in the near future with growing human population pressure.

Country/Territory	Occurrence status	Presence	Resident	Breeding	Non-breeding	Passage
Vietnam	N	Extant	Yes

Country/Territory	IBA Name
Vietnam	Chu Yang Sin
Vietnam	Tuyen Lam

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	900 - 1700 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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Shifting agriculture	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		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
Natural system modifications	Dams & water management/use - Large dams	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2021) Species factsheet: Laniellus langbianis. Downloaded from http://www.birdlife.org on 04/08/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/08/2021.