Sulu Boobook Ninox reyi


Justification of Red List Category
This recently-split hawk-owl is known from just six small islands, on which habitat loss and degradation have been extensive, owing to a variety of threats including clearance for agriculture, orchards and grazing livestock. The total population is likely to be very small, with all subpopulations containing fewer than 1,000 mature individuals and in continuing decline. It is therefore listed as Vulnerable.

Population justification
A preliminary global population estimate is of 1,000-2,499 mature individuals, with the largest of the six island subpopulations (probably on Tawi-Tawi) thought to number 250-1,000 mature individuals.

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, and logging.

Distribution and population

Ninox reyi is found on Sulu, Siasi, Tawi-Tawi, Sanga Sanga, Bongao and Sibutu in the Sulu islands, Philippines (Rasmussen et al. 2012).


In the absence of specific information, this species's ecological requirements are assumed to be similar to N. philippensis, which inhabits primary and tall secondary forest, from the lowlands to c.1,000 m, locally to 1,800 m (König and Weick 2008). On Tawi-Tawi the species is also found in forest edge, mature mangroves and large trees in the vicinity of villages (Rasmussen et al. 2012).


Satellite images of Siasi appear to show that almost the entire island’s forest has been replaced by orchards, while Sulu (Jolo) has apparently also been largely converted except around the volcanic cones, Sanga-Sanga’s last forest patch was cleared in 1992-1993, and Bongao retains only a small patch of forest on its sacred mountain (Rasmussen et al. 2012). Sibutu may have significant areas of secondary forest, although maybe largely of low stature (Rasmussen et al. 2012). The main island of Tawi-Tawi still had much secondary and some primary forest in the mid 1990s (Dutson et al. 1996) but remaining habitat is under pressure from conversion for oil palm plantations. However, on Tawi-Tawi N. reyi it may be able to tolerate some habitat degradation as it can be found in forest edge, mature mangroves and large trees in the vicinity of villages (Rasmussen et al. 2012).

Conservation actions

Conservation and research actions underway
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. Initiate education and awareness campaigns to raise the species's profile and instil pride in local people. Lobby for protection of remaining forest.


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

Hutchinson, R.

Recommended citation
BirdLife International (2021) Species factsheet: Ninox reyi. Downloaded from on 26/11/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 26/11/2021.