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

Taxonomic note
Closely related to T. novaehollandiae, T. nigrobrunnea and T. inexspectata. Until recently, often considered conspecific with T. inexspectata. Monotypic.

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2024	Near Threatened	B1b(iii)
2016	Vulnerable	D1
2015	Vulnerable	D1
2012	Endangered	B1ab(ii,iii,v);C2a(ii)
2008	Endangered	B1a+b(ii,iii,v); C2a(ii)
2004	Endangered
2000	Endangered
1996	Vulnerable
1994	Vulnerable
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,500 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	unknown	-
Population trend	decreasing	poor	suspected	2017-2032
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Generation length	4.84 years	-	-	-
Number of subpopulations	1-2,1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Population size unknown, with no records between the collection of the type specimen in 1938 (White and Bruce 1986), and the first field observation in October 1991 (Stones et al. 1995). It has since been found by several visitors to the island (Rheindt 2010, Bruce et al. 2020, eBird 2024), and Eaton et al. (2016) considered it a ‘scarce’ species. As a nocturnal species it is assumed to have very low detectability, and likely to be overlooked. Taliabu is not a very small island (3,000 km²), hence the population size of this species, even if only a small percentage of the island is occupied, is unlikely to be very small given the species utilises forest edge as well as interior forests. If the species is found on other islands in the Sula archipelago, its population size will be even greater.

Trend justification:

A remote sensing analysis in this species’ range over the past three generations (2007-2022) indicates a decline in tree cover of 21.9 kha, equivalent to a 7.9% decrease in tree cover (Global Forest Watch (2024) based on data from Hansen et al. (2013) and methods therein). This decline in tree cover is suspected to be negatively impacting the population, given the species' presumed dependence on forest habitat. However, records show that this species has been found in dense secondary bamboo thickets at 90 m, heavily logged forest with no understory at 900 m, as well as selectively logged lowland forest (Rheindt, 2010, Davidson et al. 1995). It has also been observed in coconut plantations and occasionally in close proximity to human habitation (Bruce et al. 2020). This indicates both a broad elevational range and a tolerance for disturbed habitat.

Estimating the population trend of this species is challenging due to an absence of information. However it is concluded, somewhat precautionarily, that rates of forest cover loss are having a proportional impact on this species' population size. Accordingly, the species is suspected to have declined by 1-15% over the past three generations, with the same rate suspected to occur in the future, with no evidence that Taliabu's lowland forests are being adequately safeguarded from future clearance.

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

Country/Territory	IBA Name
Indonesia	Taliabu Utara

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	marginal	non-breeding
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 900 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	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 - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Taliabu Masked-owl Tyto nigrobrunnea. Downloaded from https://datazone.birdlife.org/species/factsheet/taliabu-masked-owl-tyto-nigrobrunnea on 22/11/2024.
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 22/11/2024.