Small, long-tailed Curruca warbler, very similar to Spectacled and Subalpine Warblers. Males are distinctive with very deep rusty underparts, a rusty throat (sometimes paler mid-throat), rusty wings, and a hint of pale buff moustache. Females are pale brown and less distinctive with normally rather warm-toned underparts. Breeds on mountain slopes covered in dense, low bushes, tamarisk scrub, and vegetated desert wadis; non-breeding habitat is sometimes lower in elevation, but typically similarly open and scrubby. Song a scratchy whistle. Call a low "trrrrr."