Current view: Data table and detailed info
Taxonomic note
Ninox squamipila, N. hypogramma, N. hantu and N. forbesi (del Hoyo and Collar 2014) were previously lumped as N. squamipila following Norman et al. (1998), and before then were also lumped with N. natalis as N. squamipila following Sibley and Monroe (1990, 1993).
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. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
IUCN Red List criteria met and history
Red List criteria met
Red List history
Migratory status |
not a migrant |
Forest dependency |
medium |
Land-mass type |
|
Average mass |
- |
Population justification: The population size of this species has not previously been quantified, although it is described as fairly common (Coates and Bishop 1997; Eaton et al. 2016, 2021). Within this species' range, c.3,000 km2 of forest remains (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Densities of congeners range widely. Based on territory size data, Jakosalem et al. (2013) thought N. rumseyi could occur at densities of up to 20 mature individuals/km2, but for the similarly sized N. boobook, Olsen et al. (2011) found territory sizes up to 10 times bigger. It is likely that N. forbesi occurs at densities closer to the former, with reports of four pairs recorded from a single point, including two within 100 m of one another in 2022 (J. Eaton in litt. 2023). Assuming an approximate density of 8-20 mature individuals/km2, and that 50-80% of suitable habitat is occupied, the population is inferred to number 12,000-48,000 mature individuals.
Trend justification: Data on population trends for this species are lacking. Although forest cover loss is ongoing (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein) at a rate of c.5% over the past three generations (15.6 years: 2006-2022), most losses have been along roads, and this species is noted as being very tolerant of degraded forest, even that with cleared undergrowth (J. Eaton in litt. 2023). In the absence of other threats, the population is suspected to be stable.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Tanimbar Boobook Ninox forbesi. Downloaded from
https://datazone.birdlife.org/species/factsheet/tanimbar-boobook-ninox-forbesi on 26/12/2024.
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 26/12/2024.