The Marcapata Spinetail is a Cranioleuca spinetail endemic to central and southern Peru. It inhabits the undergrowth of montane forest, especially bamboo, between 2700 and 3400 meters in elevation. There are two distinct subspecies of Marcapata Spinetail. Both are rufous above with a gray face, neck, and supercilium, separated from the crown by a thin black line, and both have gray underparts with a white throat. The two subspecies differ dramatically, however in the color of the crown. The crown is rufous, like the back, in the nominate subspecies of eastern Cuzco, but is white in the northern subspecies weskei of Junín; this gives weskei a striking similarity to the Light-crowned Spinetail (Cranioleuca albiceps) of Bolivia and extreme southeastern Peru. Marcapata Spinetail frequently associates with mixed-species flocks of understory insectivores. The song is a descending series of staccato notes.