Robsonius rabori 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Timaliidae

Scientific Name: Robsonius rabori
Species Authority: (Rand, 1960)
Common Name(s):
English Rusty-faced Babbler
Taxonomic Notes: Napothera rabori (Sibley and Monroe 1990, 1993) has been moved into the new genus Robsonius and split into R. rabori and R. sorsogonensis following Collar (2006).
Identification information: 20-22 cm. Rather long-billed and long-legged ground-haunting babbler. Brownish above with dull rusty-chestnut head, grey below with black markings and white streaks, and bold white spots on wings. Crown is rusty rufous with narrow black scales, and plainer and rustier on very fluffy lower upperparts and tail. Median and greater upperwing-coverrts rufescent olive with black subterminal marks and bold white tips, outer primaries also tipped white. Lores white, face plain rusty chestnut, broad submoustachial strip white, narrow malar line black but broadening distally and breaking up into black spots on side of throat. Chin and throat white, lower throat with scattered black spots. Voice Song a variable, extremely high, wispy, slurred insect-like "tsui-ts'siiuu'ee", rising at end, lasting 1.7-1.9 seconds.

Assessment Information [top]

Red List Category & Criteria: Vulnerable B1ab(ii,iii,v) ver 3.1
Year Published: 2014
Date Assessed: 2014-07-24
Assessor(s): BirdLife International
Reviewer(s): Butchart, S.
Contributor(s): Allen, D., Gonzalez, J., Hosner, P. & Hutchinson, R.
Facilitator/Compiler(s): Allinson, T, Calvert, R., Symes, A. & Taylor, J.
This species is listed as Vulnerable as it has a small range, in which it is found at a limited number of locations, and its habitat is declining both in area and quality as a result of deforestation. Recent data, however, suggest that it may be present at more localities than previously thought. The taxonomic treatment of this species is under review and may change in the near future.

Previously published Red List assessments:
2012 Vulnerable (VU)
2010 Vulnerable (VU)
2008 Not Recognized (NR)
2004 Not Recognized (NR)
2000 Not Recognized (NR)
1994 Not Recognized (NR)
1988 Not Recognized (NR)

Geographic Range [top]

Range Description: Robsonius rabori is found in northern Luzon, Philippines. It is considered uncommon, although tape playback indicates it may be widely overlooked (del Hoyo et al. 2007), and it has been described as fairly common around Adams in north-western Luzon and at Mt. Cagua in north-eastern Luzon (P. Hosner in litt. 2012). The population is thought to be declining owing to habitat destruction (del Hoyo et al. 2007, R. Hutchinson in litt. 2010).

Countries occurrence:
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 15200
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 6-10
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 global population size has not been quantified, although it has been described as uncommon. However, it may be more common than suggested by field observations, owing to its secretive habits (del Hoyo et al. 2007).

Trend Justification:  This species is suspected to be declining at an unquantified rate owing to habitat destruction (del Hoyo et al. 2007, R. Hutchinson in litt. 2010).

Current Population Trend: Decreasing
Additional data:
Number of mature individuals: Unknown Continuing decline of mature individuals: Yes
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 found in lowland forest and secondary growth from sea-level to 1,300 m. It presumably feeds on invertebrates, and has been observed walking across the forest floor searching for prey in the leaf litter, sometimes in pairs (del Hoyo et al. 2007, J. C. Gonzalez in litt. 2010). It is often encountered in the vicinity of small streams (D. Allen in litt. 2012). Very little is known about its breeding habitats. Its nest is a large dome made of dry sticks, branches and leaves (Sánchez-González et al. 2010).

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 5.5
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Logging within its elevational range has been described as extensive (del Hoyo et al. 2007).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
It is present in the Northern Sierra Madre Natural Park (del Hoyo et al. 2007).

Conservation Actions Proposed
Assess the population size and establish a monitoring programme to establish trends. Establish its ability to persist in degraded habitats. Identify and assess threats. Ensure that the Northern Sierra Madre Natural Park is effectively protected

Citation: BirdLife International. 2014. Robsonius rabori. The IUCN Red List of Threatened Species 2014: e.T22735840A61675120. . Downloaded on 29 November 2015.
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