Ninox rudolfi 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Strigiformes Strigidae

Scientific Name: Ninox rudolfi
Species Authority: Meyer, 1882
Common Name(s):
English Sumba Boobook
Spanish Nínox de Sumba
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. Lynx Edicions BirdLife International.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Benstead, P., Bird, J., Khwaja, N., Taylor, J.
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.

Previously published Red List assessments:
2008 Near Threatened (NT)
2004 Near Threatened (NT)
2000 Lower Risk/near threatened (LR/nt)
1996 Vulnerable (VU)
1994 Vulnerable (VU)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: 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.

Countries occurrence:
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 10700
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 1000
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: 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).
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 6000-15000 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 1 Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: Yes
No. of individuals in largest subpopulation: 100

Habitat and Ecology [top]

Habitat and 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.

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 4.1
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Forest cover is threatened by extensive clearing and repeated burning for grazing and agriculture.

Conservation Actions [top]

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.

Citation: BirdLife International. 2012. Ninox rudolfi. The IUCN Red List of Threatened Species 2012: e.T22689398A40413892. . Downloaded on 29 November 2015.
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