Romblon Boobook Ninox spilonotus


Justification of Red List Category
This recently-split hawk-owl is known with certainty from just two islands, on which habitat loss and degradation have been extensive, owing to a variety of threats including clearance for agriculture and grazing, gold mining and logging. The total population is likely to be very small, with both sub-populations containing fewer than 250 mature individuals and in continuing decline. It is therefore listed as Endangered.

Population justification
The global population estimate was previously estimated at 1,000-2,499 mature individuals, however it has been suggested that each island may only contain 100-200 mature individuals given the amount of cover on the islands (R. Hutchinson in litt. 2016). Congeners have been reported to have range sizes up to 206 or even 307 ha (Olsen et al. 2011, Pryde and Green 2016), and bird density can be low on Sibuyan (D. Allen in litt. 2013). Therefore, it is plausible that sub-population sizes may be this low. As such, the overall population size would be <500 mature individuals, and so would fall into the range of 250-999 mature individuals, with <250 mature individuals per sub-population.

Trend justification
This species's population is suspected to be in decline owing to continued deforestation, driven by the expansion of agriculture, clearance for livestock, logging and mining.

Distribution and population

Ninox spilonotus is endemic to the islands of Sibuyan and Tablas (with unconfirmed reports of a Ninox taxon on Romblon) in the Philippines (Rasmussen et al. 2012).


Inhabits primary and tall secondary forest, from the lowlands to c.1,000 m (Allen 2006, König and Weick 2008).


Extensive forest clearance has taken place on Tablas since the beginning of the 20th century, with a substantial proportion of the island now used for cultivation and livestock-rearing (del Hoyo et al. 2009). Rice fields are common in lowland areas, while rough pasture and coconut plantations are found in the hills. Satellite images taken in the late 1980s suggested Tablas then held two forest parcels together covering under 0.5 km2 (Goodman & Ingle 1993) and more recent visits confirm that the amount of habitat there is tiny, although the species occurs in tall secondary as well as primary forest on the island (Allen 2006). Small-scale logging is reported to still be a threat (del Hoyo et al. 2009), implying that suitable habitat continues to be lost, but the rate of loss is probably no longer rapid (D. Allen in litt. 2011). Meanwhile, although forest covered over half of Sibuyan’s 233 km2 land surface at the start of the 1990s, logging was proceeding apace and, in the absence of intervention, all lowland areas were predicted to be cleared within a few years (Goodman & Ingle 1993); illegal logging inside Mt Guiting-guiting Natural Park continues (M. Wallbank verbally 2009 to D. Allen, in Rasmussen et al. 2012), and there is extensive habitat destruction for gold-mining (D. Allen in litt. 2013).

Conservation actions

Conservation and research actions underway
Forest on Mt Palaupau is protected as a watershed (del Hoyo et al. 2009). No targeted actions are known for this species.

Conservation and research actions proposed
Carry out surveys to assess the population size. Study the species's ecology and life history. Monitor population trends. Monitor the extent and condition of suitable habitat. Increase the area of remaining forest that is afforded protection. Assess the feasibility and effectiveness of forest restoration, especially in the south of the island. Initiate education and awareness campaigns to raise the species's profile and instil pride in local people.


Text account compilers
Taylor, J., Westrip, J., Ekstrom, J., Butchart, S., Symes, A.

Allen, D., Hutchinson, R.

Recommended citation
BirdLife International (2021) Species factsheet: Ninox spilonotus. Downloaded from http://www.birdlife.org on 05/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/12/2021.