Family Grasshopper-warblers and Grassbirds (Locustellidae)

Near Threatened

Bicol Ground-warbler (Robsonius sorsogonensis)


French: Robsonie du Sorsogon German: Braungesicht-Grundsänger Spanish: Ratina de Rand
Other common names: Grey-banded Babbler

Napothera sorsogonensis

Rand and Rabor

, 1967,

Mount Bulusan, San Roque, Bulusan, Sorsogon Province, southern Luzon, Philippines


Formerly regarded as conspecific with R. rabori (and the then undescribed R. thompsoni); the remark that these three taxa, and in particular the present form, are “PSC species”#R misrepresents the degree of differentiation involved. Name mesoluzonica given to birds in N of range, shown to be a synonym#R. Monotypic.


C & S Luzon and Catanduanes, in NC Philippine Is.

Descriptive notes

20–22 cm; 57–65 g. Nominate race has forehead greyish olive, shading on crown to olive, all with faint dark scales; mantle and upper back olive with faint narrow... read more


Song a very high, thin, high-pitched “tit’tsu—tsuuuu-tsiiiiii” (third and fourth notes higher,... read more


Broadleaf evergreen forest, forest edge, secondary growth, vicinity of limestone rocks and outcrops... read more

Food and feeding

Stomach of one specimen held insects; presumably many types of invertebrate taken. Forages on ground, walking slowly across forest floor,... read more


Feb–Aug, with a dependent fledgling observed in late Feb. Nest a large ball with large front entrance, placed 0·6–0... read more



Status and conservation

Not globally threatened. Currently considered Near Threatened. Restricted-range species: present in Luzon EBA. Status difficult to determine owing to secretive habits.... read more

Recommended citation

Collar, N., Robson, C. & Sharpe, C.J. (2018). Bicol Ground-warbler (Robsonius sorsogonensis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 24 September 2018).