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

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.
Holt, D. W.; Berkley, R.; Deppe, C.; Enriquez Rocha, P. L.; Olsen, P. D.; Petersen, J. L.; Rangel Salazar, J. L.; Segars, K. P.; Wood, K. L. 1999. Strigidae (typical owls). In: del Hoyo, J.; Elliott, A.; Sargatal, J. (ed.), Handbook of the birds of the world, pp. 76-242. Lynx Edicions, Barcelona, Spain.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Near Threatened	B1b(iii)
2016	Vulnerable	B1ab(ii,iii,v); C2a(ii)
2014	Vulnerable	B1ab(ii,iii,v); C2a(ii)
2012	Endangered	B1ab(ii,iii,v)
2008	Endangered	B1a+b(ii,iii,v)
2004	Endangered
2000	Endangered
1994	Not Evaluated
1988	Near Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,600 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	15000-45000, 15000-20000 mature individuals	poor	suspected	2022
Population trend	decreasing	poor	suspected	2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Generation length	3.04 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population size of this species has not previously been directly quantified. The densities of other Otus species is also surprisingly poorly known. Otus rufescens occurs at densities of c. 20 birds/km² in Sarawak (Fogden 1976), but the applicability of those data to the present species is wholly unknown. Using the global landcover 2 estimate of forest cover for the island (closed to open broadleaved evergreen or semi-deciduous forest) and excluding fragments smaller than 1 km² results in an area classified as forest habitat of 1,572 km². If a density of 10-30 birds/km² is applied to this area (a range centred on the density of O. rufescens, but acknowledging uncertainty on the appropriateness of this), a population size of c.15,000-45,000 mature individuals is yielded. Qualitative descriptions of the species' abundance of the species vary from 'fairly common and widespread' (Beehler and Pratt 2016) to 'rare' (Gregory 2017), while eBird data suggest it is indeed widespread, but is rarely encountered in large numbers. The lower bound of this estimate (15,000-20,000 mature individuals) is precautionarily considered the best, although this requires confirmation.

Trend justification: No direct assessment of rate of population change has been made for the species. It is considered to be forest dependent and there has been a slow rate of forest cover loss, up to 4% in the ten years to 2022 (data from Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein) and this is suspected to be causing broadly equivalent reductions in population size of this species. These rates are suspected to occur in the future. An accelerated rate of decline is considered unlikely given the impenetrability of Supiori's forests.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Swamp	major	resident
Altitude	0 - 1000 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder 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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Biak Scops-owl Otus beccarii. Downloaded from https://datazone.birdlife.org/species/factsheet/biak-scops-owl-otus-beccarii on 22/12/2024.
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 22/12/2024.