Justification of Red List Category
Assessment of the status of this species is hampered by its considerable obscurity. Given its apparent rarity and the continuing loss and degradation of forest habitat on Sulawesi, it seems reasonable to surmise that its population is small and declining, qualifying it as Vulnerable.
The population size is preliminarily estimated to fall into the band 2,500-9,999 mature individuals. This equates to 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals.
Deforestation has occurred at lower elevations within the species's range. This on-going threat suggests that its population is declining, although the rate of decline is suspected to be moderate owing to limited impacts on montane forests.
Ninox ios is apparently restricted to the highlands of Sulawesi, Indonesia (BirdLife International 2001). Since the collection of the type specimen in Bogani Nani Wartabone National Park in 1985, there have been records from Gunung Ambang Strict Nature Reserve and from Lore Lindu National Park (Central Sulawesi), where it may be fairly common (Mauro 2001, King 2005, Hutchinson et al. 2006, eBird 2017, B. King and R. Hutchinson in litt. 2012); although elsewhere it could be sparsely distributed (K. D. Bishop in litt. 2012).
The known records (including that of the type specimen) are from forest between 1,120 m and 1,700 m, and it is assumed that the species is sympatric with, but probably at higher elevations than, the Ochre-bellied Hawk-owl N. ochracea (Hutchinson et al. 2006), and N. punctulata (in Lore Lindu [B. King in litt. 2012]). Observations and comparison with owlet-nightjars (Aegothelidae) suggests that the species feeds predominantly on flying insects by conducting short sallies from exposed branches (Hutchinson et al. 2006).
Forest at middle elevations on Sulawesi is relatively intact at present. However, deforestation is having a major impact in many areas, and until it is demonstrated that the species occurs more widely than its current three localities, it is precautionary to regard it as at risk simply on the basis of its potentially restricted population. The drivers behind on-going deforestation are thought to be rural development and encroachment of settlements, agricultural expansion and logging pressure. Oil palm plantations are a major cause of deforestation in many parts of Indonesia. As a species of montane areas, it is potentially at risk from the effects of projected climate change on the distribution and extent of its habitats.
Conservation Actions Underway
CITES Appendix II. The species occurs within three protected areas: Bogani Nani Wartabone National Park, Gunung Ambang Strict Nature Reserve and Lore Lindu National Park.
c.22 cm. Small, brightly coloured hawk-owl. Uniform rufous-chestnut but for whitish scapular spots, whitish feather shafts on underparts, indistinct darker scalloping to lower underparts, and narrow, darker bars on retrices. Lacks any facial patterning. Similar spp. Speckled Hawk-owl N. punctulata, Brown Hawk-owl N. scutulata and Ochre-bellied Hawk-owl N. ochracea are larger with more prominently patterned faces. N. punctulata is spotted white on upperparts and barred white on underparts, N. ochracea and N. scutulata are dark brown, the former with paler yellow-ochre lower underparts, the latter with brown-streaked white underparts.
Text account compilers
Tobias, J., Allinson, T, Benstead, P., Westrip, J., Taylor, J., Bird, J.
King, B., Hutchinson, R., Bishop, K.
BirdLife International (2020) Species factsheet: Ninox ios. Downloaded from http://www.birdlife.org on 04/07/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/07/2020.