Identification
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 Buru Bush Warbler and Seram 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 Sulawesi and Seram Bush Warblers, but ranges do not overlap. Calls include a sharp metallic “chit” and a drawn-out, wavering buzzy note, “tzeeoooreee.” There is some variation in songs, which usually comprise three high-pitched buzzing notes, “tzeeee-tzeee-tzeee,” higher-pitched on the final note. Song includes a high, liquid-sounding “tzi-tzee”, as well as a longer, more repetitive “tzi-tzee, tzi-tzee, tzi-tzee.”