Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern.
The population was previously (in 2003) estimated preliminarily to fall in the band 2,500-9,999 mature individuals, however no species-specific density is known, and the species is now known to be considerably more widespread than formerly thought. It is described as locally common (Berryman and Eaton 2020, Eaton et al. 2021) and four birds heard calling along a 1-km transect on a forest track in the Mekongga mountains in south-east Sulawesi indicate the species may, at least locally, be capable of occurring at a relatively high density (A. Berryman in litt. 2021). Consequently, although the population is unknown, it is not suspected to approach the thresholds for listing as threatened.
Given this species' occurrence in montane forests, encroachment by agriculture and timber extraction has been minimal in its range. Global Forest Watch (2021) data, using Hansen et al. (2013) methods and data disclosed therein, suggest that forest loss in its range has been minimal (c.2.5% over three generations: 12.7 years, Bird et al. 2020) and is not necessarily above the rate of natural flux. The population is therefore suspected to be stable, but may decline if forest loss begins to encroach on higher elevation forest.
Ninox ios is 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 2021, B. King and R. Hutchinson in litt. 2012); more recently it was found in the Mekongga Mountains in South-east Sulawesi (Berryman & Eaton 2020).
All records of this species are from montane forest above 1,100 m, to at least 1,800 m (Berryman and Eaton 2020, Eaton et al. 2021), where it assumed to replace the more lowland N. ochracea and N. punctulata (Hutchinson et al. 2006). Observations suggest 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 at lower elevations and these could encroach higher up in the future. The drivers behind on-going deforestation are thought to be rural development and encroachment of settlements, agricultural expansion and logging pressure. 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
Allinson, T, Benstead, P., Berryman, A., Bird, J., Bishop, K.D., Hutchinson, R., King, B., Taylor, J., Tobias, J. & Westrip, J.R.S.
BirdLife International (2023) Species factsheet: Ninox ios. Downloaded from http://datazone.birdlife.org/species/factsheet/cinnabar-boobook-ninox-ios on 28/05/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 28/05/2023.