EN
Grey-crowned Crocias Laniellus langbianis



Taxonomy

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.

IUCN Red list criteria met and history
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
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Land-mass type - continent
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 7,200 medium
Number of locations 2-5 -
Fragmentation -
Population and trend
Estimate 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 - - -
Largest subpopulations - - -
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 distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Vietnam N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Vietnam Chu Yang Sin
Vietnam Tuyen Lam

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Montane major resident
Altitude 900 - 1700 m Occasional altitudinal limits  

Threats & impact
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

Recommended citation
BirdLife International (2019) Species factsheet: Laniellus langbianis. Downloaded from http://www.birdlife.org on 12/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 12/12/2019.