Nesasio solomonensis 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Strigiformes Strigidae

Scientific Name: Nesasio solomonensis
Species Authority: (Hartert, 1901)
Common Name(s):
English Fearful Owl
Spanish Búho de las Salomón
Nesasio solomensis solomensis Collar and Andrew (1988)
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: 38 cm. Massive forest owl. Golden eyes framed by prominent creamy eyebrows, otherwise warm brown. Streaked dark underparts and barred dark upperparts. Similar spp. Solomons Islands Hawk-owl 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.

Assessment Information [top]

Red List Category & Criteria: Vulnerable C2a(i) ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Symes, A. & Butchart, S.
Contributor(s): Dutson, G., Hafe, M. & Webb, H.
Facilitator/Compiler(s): Derhé, M., Dutson, G., Mahood, S., O'Brien, A., Stattersfield, A.
This enigmatic species is classified as Vulnerable on the basis of a small population which is declining through habitat loss and is likely to be fragmented into very small subpopulations across three islands. However, its total population size, habitat requirements, and rate of decline are very poorly known.

Previously published Red List assessments:
2008 Vulnerable (VU)
2004 Vulnerable (VU)
2000 Vulnerable (VU)
1996 Vulnerable (VU)
1994 Vulnerable (VU)
1988 Near Threatened (NT)

Geographic Range [top]

Range Description: 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. It is presumed to be a species of low population density as it is rarely seen and no more than one bird has been heard calling from any location. In a well-studied area at Tirotonga on Isabel, three nests were about 2 km apart (G. Dutson pers. obs. 1998, M. Hafe verbally 1998), which would extrapolate to an approximate total population of c.3,000 pairs, but it appears to be unusually common in this area (G. Dutson pers. obs. 1998).

Countries occurrence:
Papua New Guinea; Solomon Islands
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 13200
Continuing decline in extent of occurrence (EOO): Yes
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 11-100
Continuing decline in number of locations: Yes
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 700
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The population is estimated to number at least 6,000 individuals, equivalent to 4,000 mature individuals (G. Dutson pers. obs. 1998, M. Hafe verbally 1998).

Trend Justification:  Forest loss and degradation are suspected to be causing this species to decline at a moderate rate.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 4000 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 2-100 Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: 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 1975a, Webb 1992). Phalangers 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 (Webb in litt. 1996, G. Dutson pers. obs. 1998).

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 5.4
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): This species is threatened by large-scale logging and deforestation in the lowlands, which has increased in intensity in recent years (G. Dutson in litt. 2007). It may also be less common in areas where rural communities over-hunt prey species P. orientalis (Dutson 2011).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CITES Appendix II. No conservation measures known.

Conservation Actions Proposed
Survey to determine population densities in primary and logged forest, hunted and unhunted areas and at various altitudes. Monitor population trends around Tirotonga. Research diet and breeding success at Tirotonga. Lobby for tighter controls of commercial logging, especially on Choiseul. Discuss possibilities of large-scale community-based conservation areas on all three islands. Promote this species as a figurehead species for community-based conservation and ecotourism initiatives.

Citation: BirdLife International. 2012. Nesasio solomonensis. The IUCN Red List of Threatened Species 2012: e.T22689539A38249363. . Downloaded on 26 November 2015.
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