CR
Siau Scops-owl Otus siaoensis



Taxonomy

Taxonomic note
Otus magicus and O. tempestatis (del Hoyo and Collar 2014) were previously lumped as O. magicus, and O. alfredi, O. siaoensis, O. enganensis, O. insularis and O. beccarii (del Hoyo and Collar 2014) were split from O. magicus following Widodo et al. (1999), Lambert and Rasmussen (1998), Andrew (1992) and Holt et al. (1999). Prior to that all these taxa were lumped in O. magicus 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.
Lambert, F. R.; Rasmussen, P. C. 1998. A new scops owl from Sangihe Island, Indonesia. Bulletin of the British Ornithologists' Club 118: 204-217.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
D D D1+2

Red List history
Year Category Criteria
2018 Critically Endangered D
2016 Critically Endangered D
2012 Critically Endangered D
2009 Critically Endangered D1
2008 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 160 km2 medium
Number of locations 1 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 1-49 mature individuals poor estimated 2000
Population trend stable - suspected -
Generation length 3.7 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: The population is estimated to number fewer than 50 individuals and mature individuals, based on analyses of recent searches and reports, the extent of habitat destruction within its range, and the conclusion that it seems likely that any surviving population will prove minute.

Trend justification: The population is suspected to be stable in the absence of evidence for any declines or substantial threats.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Indonesia Pulau Siau

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Subtropical/Tropical Heavily Degraded Former Forest possible unknown
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 1500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Scale Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Majority (50-90%) Unknown Unknown
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Unknown Unknown
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2024) Species factsheet: Siau Scops-owl Otus siaoensis. Downloaded from https://datazone.birdlife.org/species/factsheet/siau-scops-owl-otus-siaoensis on 25/12/2024.
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 25/12/2024.