Data Zone
Justification of Red List category
This species has a small population size that is suspected to be declining at a rate exceeding 10% in three generations owing to ongoing forest loss within its range, with the largest subpopulation plausibly numbering less than 1,500 mature individuals. It is therefore classified as Near Threatened.
Population justification
Overall the species is poorly known. It is described as widespread but uncommon and sparsely distributed (Dutson 2011, Woxvold and Novera 2021). In a well-studied area at Tirotonga on Isabel, three nests were reportedly about 2 km apart in 1998, however it appeared to be unusually common in this area (G. Dutson pers. obs. 1998) and elsewhere there have been records only of singles or single pairs. Considering this along with the fact that the species has likely declined in line with forest loss within its range, the population size is estimated to fall in the band 2,500 - 10,000 mature individuals.
Trend justification
Forest loss and degradation are inferred to be causing this species to decline at a moderate rate. Remote sensing data (Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein) indicate that over the last three generations (22.29 years; Bird et al. 2020) forest loss in this species' range has been equivalent to c.10%, and based on losses in 2017-2021 forest loss has accelerated to an equivalent rate of c.15% within three generations. Three nests were reportedly about 2 km apart in 1998 at Tirotonga (G. Dutson pers. obs. 1998, M. Hafe verbally 1998) and the species appeared to be unusually common in this area (G. Dutson pers. obs. 1998). However, more recently there is seemingly only one pair in the vicinity of Tirotonga (J. Bergmark in litt. 2023), suggesting that the species has declined. There have been very few sightings of the species in the last decade (Woxvold and Novera 2021, J. Bergmark in litt. 2023). In addition to forest loss, the species is possibly also declining through loss of prey which is also hunted by humans (Dutson 2011). The species appears to be highly forest dependent and forest loss is considered to be causing declines at a rate at least equal to that of forest loss; population declines are here placed in the band 10-19% over three generations.
Nesasio solomonensis is endemic to Bougainville in Papua New Guinea and Choiseul and Santa Isabel in the Solomon Islands. There are also possible reports from Buka.
This large owl is the top predator along with Sanford's Fish-eagle Haliaeetus sanfordi and is reported to feed mostly on Northern Common Cuscus Phalanger orientalis (Diamond 1975, Webb 1992). Cuscus were introduced to these islands in prehistoric times; presumably the owl previously fed on the giant arboreal rats which are now very rare across their range (Flannery 1995). Its distribution may now mirror that of P. orientalis which is heavily hunted for food in some districts (Webb 1992). All records are from old-growth lowland and hill forest, usually in primary forest but also in adjacent secondary forest and forest edge to at least 2,000 m (Gardner 1987, Webb 1992, G. Dutson pers. obs. 1998, Dutson 2011). Three nests on Isabel were on ephiphyte-covered branches of huge fig trees, one was in primary forest, the other two in forest edge close to many gardens (H. Webb in litt. 1996, G. Dutson pers. obs. 1998).
This species is threatened by large-scale logging and deforestation in the lowlands, which has increased in intensity in recent years, and most of the lowlands of Choiseul and Santa Isabel have been logged or have logging concessions (Katovai et al. 2015). It may also be less common in areas where rural communities over-hunt prey species P. orientalis (Dutson 2011).
Conservation Actions Underway
CITES Appendix II. No conservation measures known.
38 cm. Massive forest owl. Golden eyes framed by prominent creamy eyebrows, otherwise warm brown. Streaked dark underparts and barred dark upperparts. Similar spp. West Solomons Boobook Ninox jacquinoti is much smaller (25-30 cm) with plainer facial mask, dark eyes and faintly patterned underparts. Voice Similar to clear human cry, increasing in volume and tone, given as series at 10 second intervals. Hints Rarely seen unless a local guide knows of regular roost or nest-sites.
Text account compilers
Vine, J.
Contributors
Bergmark, J., Dutson, G., Hafe, M. & Webb, H.P.
Recommended citation
BirdLife International (2024) Species factsheet: Fearful Owl Nesasio solomonensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/fearful-owl-nesasio-solomonensis on 24/11/2024.
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 24/11/2024.