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. Adult has forehead greyish olive, shading on crown to olive, all with faint dark scales; mantle and upper back olive with faint narrow dark... read more


Song a very high, thin, high-pitched “tit’tsu—tsuuuu-tsiiiiii” (third and... 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. (2020). 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 23 February 2020).