|Scientific Name:||Robsonius sorsogonensis|
|Species Authority:||(Rand & Rabor, 1967)|
|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. Forehead greyish-olive, shading on crown to olive, all with faint dark scales. Mantle and upper back olive with faint narrow dark scales, becoming uniform brown on lower back, paler on rump, where white tips of feathers form semi-concealed bar, uppertail-coverts dark rufescent brown, tail dark brown. Flight-feathers broadly edged brown with bold white tips on outer two and indistinct tip on third. Lores and narrow supercilium to above eye white, cheek and ear-coverts grey, finely streaked white, submoustachial stripe white, narrow malar streak blackish. Chin to upper breast white, neck and breast sides and middle to lower breast grey. Bill blackish-brown. Voice Song a very high-pitched, thin "tit'tsu-tsuuuu-tsiiiii".|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Contributor(s):||Hosner, P., Gonzalez, J.C., Hutchinson, R. & Allen, D.|
|Facilitator/Compiler(s):||Calvert, R., Taylor, J., Allinson, T & Ashpole, J|
This species is listed as Near Threatened. It has a small range, within which it is found at a relatively limited number of locations and its habitat is declining both in area and quality as a result of deforestation; hence it almost meets the requirements for listing as threatened under criterion B1ab(ii,iii,v). If new data shows that it is found at fewer than 10 locations it would warrant uplisting to Vulnerable.
|Previously published Red List assessments:||
|Range Description:||This species is found in southern Luzon in the Philippines. P. Hosner in litt. (2012) gathered information on this species’s locality and reported that it is found at more than ten locations, including Sorsogon and Camarines Sur. 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).|
|Continuing decline in area of occupancy (AOO):||Yes|
|Extreme fluctuations in area of occupancy (AOO):||No|
|Estimated extent of occurrence (EOO) - km2:||5228|
|Continuing decline in extent of occurrence (EOO):||Unknown|
|Extreme fluctuations in extent of occurrence (EOO):||No|
|Number of Locations:||11-15|
|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:||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).
Trend Justification: There are no adequate data to quantify trends for this species, although it is suspected to be declining owing to habitat destruction (del Hoyo et al. 2007).
|Current Population Trend:||Decreasing|
|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 has been suggested that habitat quality may not be important for this species and it may actually prefer scrubby forest, especially where there is a high proportion of bamboo (R. Hutchinson in litt. 2012). 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).|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||5.5|
|Movement patterns:||Not a Migrant|
|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 and Research Actions Underway
It is present in the Quezon and Mount Isarog National Parks (del Hoyo et al. 2007).
Conservation and Research 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. 2015. Robsonius sorsogonensis. The IUCN Red List of Threatened Species 2015: e.T22735664A83679652. . Downloaded on 04 May 2016.|