VU
Large-billed Blue-flycatcher Cyornis caerulatus



Taxonomy

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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2c+3c+4c

Red List history
Year Category Criteria
2016 Vulnerable A2c+3c+4c
2012 Vulnerable A2c+3c+4c
2008 Vulnerable A2c; A3c; A4c
2004 Vulnerable
2000 Vulnerable
1994 Lower Risk/Near Threatened
1988 Near Threatened
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 2,710,000 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 6000-15000 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) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations - - -

Population justification: The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification: A rapid and on-going population decline is suspected to be occurring, given that this species is restricted to lowland primary rainforest - a habitat that is being cleared at an alarming rate across the entire range.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Brunei N Extant Yes
Indonesia N Extant Yes
Malaysia N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Brunei Belait Swamp Forest
Brunei Southern Ladan Hills
Brunei Ulu Temburong
Indonesia Betung Kerihun
Indonesia Bukit Bahar - Tajau Pecah
Indonesia Bukit Baling
Indonesia Kerinci Seblat
Indonesia Malampah Alahan Panjang
Indonesia Meranti
Malaysia Bako-Buntal Bay
Malaysia Danum Valley Conservation Area
Malaysia Dulit Range
Malaysia Kabili-Sepilok
Malaysia Kelabit Highlands
Malaysia Kinabatangan floodplain
Malaysia Lambir Hills National Park
Malaysia Lanjak Entimau Wildlife Sanctuary
Malaysia Maliau Basin Conservation Area
Malaysia Mulu - Buda Protected Area
Malaysia Niah National Park
Malaysia Tabin Wildlife Reserve
Malaysia Tawau Hills Park

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops 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 Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation
Biological resource use Logging & wood harvesting Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation
Natural system modifications Fire & fire suppression Timing Scope Severity Impact
Ongoing Minority (<50%) Rapid Declines Medium Impact: 6
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2019) Species factsheet: Cyornis caerulatus. Downloaded from http://www.birdlife.org on 21/07/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/07/2019.