Onychognathus frater 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Sturnidae

Scientific Name: Onychognathus frater
Species Authority: (Sclater & Hartlaub, 1881)
Common Name(s):
English Socotra Starling, Socotra Chestnut-winged Starling
French Etourneau de Socotra
Identification information:

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Ekstrom, J., Butchart, S., Harding, M., Fisher, S.
Although this species may have a small range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1996 Vulnerable (VU)
1994 Vulnerable (VU)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: This species is restricted to Socotra, Yemen.
Countries occurrence:
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 3600
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): 1100
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population size has not been quantified, but surveys in 1993, 1999 and 2000 have found it widespread and locally frequent all over the island (up to 1,500 m), with a mean population density (based on transects) of c.7 birds/km2 in the post-breeding season (Davidson 1996, Kirwan et al. 1996).

Trend Justification:  The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Current Population Trend: Stable
Additional data:
Number of mature individuals: Unknown Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: This species is social, highly mobile and apparently adaptable, being recorded from a broad range of habitats, although it appears to prefer methodical foraging in trees rather than on the ground (Porter and Martins 1996). The diet consists of fruit, seeds and insects (Porter and Martins 1996, Ripley and Bond 1966). It is often seen together with the more abundant Somali Starling O. blythii, which is a more conspicuous generalist and reasonably assumed to be a more recent colonist (Ripley and Bond 1966), but the possibility that the two species may be competing, to the detriment of O. frater, remains unproven speculation (Forbes-Watson 1964).
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 4.1
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Extreme overgrazing and browsing might possibly have an impact on populations, but this seems unlikely to occur in the foreseeable future.

Citation: BirdLife International. 2012. Onychognathus frater. The IUCN Red List of Threatened Species 2012: e.T22710619A39713693. . Downloaded on 27 November 2015.
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