Кобилочочка серамська Locustella musculus

A sparrow-sized dark warbler with an often scruffy-looking, graduated tail. Has dark chestnut-brown upperparts, a whitish eyebrow, a distinct white throat, and dull grayish underparts. Formerly grouped with Sulawesi Bush Warbler and Buru Bush Warbler under the name “Chestnut-backed Bush Warbler.” A secretive inhabitant of montane and foothill forest, often creeping around on or near the ground. Darker above and dingier below than Gray’s and Middendorff's Grasshopper-Warblers, and also has a clean-cut white throat; almost identical to Buru and Sulawesi Bush Warblers, but ranges do not overlap. Song is a dry, buzzy series of notes: “tzit-tzit-tzeet.”