Distinctive spinetail found mainly in the Bolivian Andes, but it also reaches over the border into southern Peru. It has a chestnut back and tail, gray underparts, and a black eyebrow. Crown is tawny in central Bolivia, and white in western Bolivia and southern Peru; this race is similar to the white-capped race of Marcapata Spinetail, but note their different ranges. Inhabits high-elevation forest, especially where there is abundant bamboo. Gives sharp chips either in a descending burst or in a longer, more frenetic series.