Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Strigiformes Tytonidae

Scientific Name: Tyto nigrobrunnea
Species Authority: Neumann, 1939
Common Name(s):
English Taliabu Masked-owl, Taliabu Masked-Owl, Taliabu Masked Owl, Sula Barn-owl, Taliabu Owl
Spanish Lechuza de la Taliabu
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. Lynx Edicions BirdLife International.
Identification information: 31-32 cm. Medium-sized, forest-dwelling owl. Female has dark brown upperparts with lines of small white spots. Dark and unbarred wings, secondaries with whitish tips, brown tail with three dark bars. Golden-brown underparts, spotted and vermiculated black. Black iris. Male presumably similar but undescribed. Similar spp. Brown Hawk-owl Ninox scutulata is smaller with yellow irides, streaked underparts and barred tail. Voice a hissing sound typical of the genus (Rheindt 2010).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(ii,iii,v);C2a(ii) ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Rheindt, F.
Facilitator/Compiler(s): Benstead, P., Bird, J., Davidson, P., Taylor, J., Tobias, J., Allinson, T
This inconspicuous and extremely poorly known forest owl is judged to qualify for Endangered because it has a very small range, and hence presumably a very small population, both of which are undergoing continuing declines on the single island it is known to inhabit. The primary factor underlying this trend is extensive logging, a threat that is set to intensify as most remaining lowland forest on the island is under timber concession.

Previously published Red List assessments:
2008 Endangered (EN)
2004 Endangered (EN)
2000 Endangered (EN)
1996 Vulnerable (VU)
1994 Vulnerable (VU)
1988 Threatened (T)

Geographic Range [top]

Range Description: Tyto nigrobrunnea is endemic to the Sula Islands, Maluku, Indonesia, where it is known from just one specimen (collected in 1938) and a handful of subsequent sight records, all from the largest island in the group, Taliabu (Davidson et al. 1991, Rheindt 2010). It is possible, however, that future surveys will reveal its presence on the neighbouring island of Mangole and perhaps Sanana (Rheindt 2010). There is no information on its population size, but the paucity of records (even taking into account its inconspicuous nature and the fact that it could easily be overlooked) indicate that it is likely to be very scarce. However, it appears to be well-known to villagers at Binadesa and recent records suggest it can occupy secondary growth and bamboo thickets in the vicinity of habitation.

Countries occurrence:
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 2900
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 1
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 800
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend Justification:  This species is suspected to be in decline as a result of extensive logging and some clear-felling on the island of Taliabu, although the likely rate of decline has not been estimated.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 250-999 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 1 Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: Yes
No. of individuals in largest subpopulation: 100

Habitat and Ecology [top]

Habitat and Ecology: Little is known of its ecology. The only specimen was collected in lowland forest, however, recent sightings have been made in heavily logged forest and dense secondary bamboo thickets suggesting that it can tolerance habitat degradation (Rheindt 2010). Unlike on other islands in the region, there is no open-country congener on Taliabu, which may have allowed it to adapt to disturbed habitats (Rheindt 2010). It apparently occurs within a broad elevational range (Rheindt 2010).

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 6.1
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Large-scale logging of lowland forest has taken place, and some areas have been clear-felled for industrial timber production. Most of Taliabu's lowland forest, below 800 m, is designated for logging concessions. Selective logging has already produced a mosaic of different-aged forest stands, with few, if any, extensive tracts of primary lowland forest remaining, except perhaps in the central south-west of the island. The effects of habitat degradation on this species remain unknown, but in combination the processes driving forest loss are thought to represent considerable threats.

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CITES Appendix II. A seven week avifaunal survey was conducted on Taliabu in 1991. A strict nature reserve has been proposed for the island, but only c.18% encompasses lowland forest, and it remains to be confirmed that this site is appropriate for the conservation of this rare owl.

Conservation Actions Proposed
Conduct widespread searches for the species (including the neighbouring islands of Mangole and Sanana), questioning local people about its possible presence and clarifying its range, distribution, status and ecological requirements. Reassess its threat status and conservation needs, recommending further areas for protection where appropriate. Ensure effective management of any forthcoming protected area on Taliabu.

Citation: BirdLife International. 2012. Tyto nigrobrunnea. The IUCN Red List of Threatened Species 2012: e.T22688449A38005330. . Downloaded on 09 October 2015.
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