Robsonius sorsogonensis


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Robsonius sorsogonensis
Species Authority: (Rand & Rabor, 1967)
Common Name(s):
English Grey-banded 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).

Assessment Information [top]

Red List Category & Criteria: Vulnerable B1ab(ii,iii,v) ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Hosner, P. & Allen, D.
Facilitator/Compiler(s): Calvert, R., Taylor, J., Allinson, T
This species is listed as Vulnerable as it has a small range, within 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. However, recent data suggest that it may be present at more localities than previously thought.

Geographic Range [top]

Range Description: Robsonius sorsogonensis is found in southern Luzon in the Philippines. It is considered uncommon, although numbers may be higher than is suggested by field observations owing to its secretive habits. The population is suspected to be declining owing to habitat destruction (del Hoyo et al. 2007).

Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population size has not been quantified. It has been described as uncommon, although it may be more common than suggested by field observations owing to its secretive habits (del Hoyo et al. 2007).
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: This species inhabits broadleaf evergreen forest, forest edge, secondary growth, and can be found in the vicinity of limestone rocks and outcrops and amongst moss-covered rocks and boulders. It ranges from the lowlands to 1,000 m, presumably feeding upon many types of invertebrates by foraging in the leaf litter. Breeding occurs from February to August, laying a clutch of two eggs (del Hoyo et al. 2007).

Systems: Terrestrial

Threats [top]

Major Threat(s): Habitat loss within its range has been, and continues to be extensive (del Hoyo et al. 2007), presumably driven primarily by agricultural expansion and timber extraction.

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
It is present in the Quezon and Mount Isarog National Parks (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 Quezon and Mount Isarog National Parks are effectively protected.

Citation: BirdLife International 2012. Robsonius sorsogonensis. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 01 September 2015.
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