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).

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. 

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.