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Sumba Boobook Ninox rudolfi

Justification
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.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

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.

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).

Ecology
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.

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

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.

References
BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

del Hoyo, J.; Elliott, A.; Sargatal, J. 1999. Handbook of the Birds of the World, vol. 5: Barn-owls to Hummingbirds. Lynx Edicions, Barcelona, Spain.

Olsen, J.; Trost, S.; Myers, S. D. 2009. Owls on the island of Sumba, Indonesia. Australian Field Ornithology 26(1-2): 2-14.

Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

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

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Ninox rudolfi. Downloaded from http://www.birdlife.org on 20/09/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/09/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Near Threatened
Family Strigidae (Typical Owls)
Species name author Meyer, 1882
Population size 6000-15000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 10,700 km2
Country endemic? Yes
Links to further information
- Additional Information on this species