CR
Rück's Blue-flycatcher Cyornis ruckii



Taxonomy

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
D D D1

Red List history
Year Category Criteria
2021 Critically Endangered D
2016 Critically Endangered D
2013 Critically Endangered D
2012 Critically Endangered D
2010 Critically Endangered D1
2009 Critically Endangered D1
2008 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status unknown Forest dependency Unknown
Land mass type Land-mass type - shelf island
Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 6,600 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 1-49 poor estimated 2000
Population trend Unknown not applicable -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -

Population justification: The population is assumed to be tiny (fewer than 50 individuals and mature individuals) based on a lack of records, despite searches, since two specimens were collected in 1917-1918.

Trend justification: Population trends are unknown and are thus not quantified.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Indonesia Tuntungan
Indonesia Gunung Leuser

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland possible resident
Altitude 150 - 200 m Occasional altitudinal limits (min) 0 m

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 Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Small-holder grazing, ranching or farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2022) Species factsheet: Cyornis ruckii. Downloaded from http://www.birdlife.org on 27/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/11/2022.