Sumba Boobook Ninox rudolfi


Justification of Red List Category
This species may have a small to moderately small population within its small range, and numbers are declining owing to on-going forest conversion. However, the range is not yet severely fragmented or restricted to few locations, thus the species is classified as Near Threatened.

Population justification
The species was reportedly relatively common and widespread in 1998, but may have declined since. Hence, the current population estimate of 10,000-19,999 individuals is very preliminary and requires clarification. This estimate equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification
The population is suspected to be in decline owing to on-going habitat destruction and degradation through burning and over-grazing (del Hoyo et al. 1999).

Distribution and population

Ninox rudolfi is restricted to Sumba, Indonesia. Although characterised as uncommon or rare, recent observations have revealed that the species is widespread and moderately common on Sumba, despite forest cover being reduced to just 10% on the island.


It occurs up to 1,000 m in primary, disturbed primary and secondary forest and forest edge, in both deciduous and evergreen formations, and mangroves (Olsen et al. 2009). It is typically found occurring singly, in pairs or small dispersed groups of up to four birds. Its diet is not known but probably consists mainly of insects.


Forest cover is threatened by extensive clearing and repeated burning for grazing and agriculture.

Conservation actions

Conservation Actions Underway
CITES Appendix II.

Conservation Actions Proposed
Clarify the species's abundance outside of forest habitats and generate a global population estimate. Determine the impact of forest clearance on the population. As a precaution, protect significant areas of suitable forest, in both strictly protected areas and community led multiple use areas.


Text account compilers
Benstead, P., Bird, J., Khwaja, N., Taylor, J.

Recommended citation
BirdLife International (2022) Species factsheet: Ninox rudolfi. Downloaded from http://www.birdlife.org on 29/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 29/11/2022.