Data Zone
Justification of Red List category
This recently-split hawk-owl is only known to occur on a single island, where its population is relatively small and is inferred to be undergoing continuing declines as its forest habitat is converted for small-scale agriculture and human settlements. It has therefore been classified as Near Threatened, pending better data on the exact population size.
Population justification
The species is only known from a single island of c.5,300 km2, on which its forest habitat is still relatively intact but suffering some losses and degradation. The known home ranges of the intensively-studied Morepork N. novaeseelandiae in New Zealand varies between 3.5 ha (Imboden 1975) and 307 ha (Pryde and Green 2016) depending on habitat productivity, with a representative home range of about 40 ha (M. Pryde in litt. 2016 per G. Dutson in litt. 2016); and similarly Southern Boobook N. boobook in Australia varies from 18 - 206 ha (Olsen et al. 2011). N. granti is heard calling at approximately similar frequencies to these two species in more productive forests (G. Dutson in litt. 2016), suggesting that there might be a handful of pairs per km2 of forest. Assuming that over half of Guadalcanal is suitable habitat (see e.g. Katovai et al. 2015, G. Dutson in litt. 2016), the population size of N. granti is precautionarily estimated to be 10,000-19,999 mature individuals (G. Dutson in litt. 2016).
Trend justification
Much of the lowland and hill forests of Guadalcanal have been logged or are under logging concessions. Although the species shows some tolerance of habitat degradation and fragmentation, it is undoubtedly undergoing slow ongoing declines owing to habitat conversion and degradation.
Ninox granti is endemic to the island of Guadalcanal in the Solomon Islands, where it has been described as fairly common (Dutson 2011).
It inhabits forest, including edges and patches of forest, up to 1,500 m, with some roosting in thickets (Dutson 2011).
There is a slow ongoing rate of forest loss for subsistence gardens and, very locally, for oil palm plantations (G. Dutson in litt. 2016). There is extensive logging but the species appears to tolerate degraded forest, albeit at unknown population densities (G. Dutson in litt. 2016). Forest at higher altitudes and on steep slopes is more secure (G. Dutson in litt. 2016).
Conservation and research actions underway
No targeted actions are known.
Conservation and research actions proposed
Carry out surveys to assess the population size and trends. Monitor population trends. Monitor the extent and condition of suitable habitat. Further research its tolerance of degraded forest across an altitudinal gradient. Work with local land-owning communities to protect significant areas of remaining primary forest.
Text account compilers
Wheatley, H., Symes, A., Dutson, G., Ekstrom, J., Taylor, J., Butchart, S.
Contributors
Dutson, G., Pryde, M.
Recommended citation
BirdLife International (2024) Species factsheet: Guadalcanal Owl Athene granti. Downloaded from
https://datazone.birdlife.org/species/factsheet/guadalcanal-owl-athene-granti on 23/11/2024.
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 23/11/2024.