Endemic to the Andes of northern Ecuador to central Peru, where it occurs between 2800 and 3900 m, the Curve-billed Tinamou is found in both humid and semi-arid puna and páramo characterized by evergreen scrub such as bunch grasses, and is occasionally also found in slash-and-burn cultivation. Well named for its markedly curved bill, the upperparts are dark brown spotted with black and streaked buffy white, while the throat is white, grading to tawny rufous over the breast, and becoming marginally paler over the rest of the underparts. The sexes are basically alike in plumage. In some areas, the species overlaps with the Andean Tinamou (Nothoprocta pentlandii), which is marginally smaller, paler above, less heavily marked below, and lacks any reddish in the wings. Two subspecies are recognised, with the Ecuadorian race being slightly larger and darker, and the Peruvian form appearing paler and smaller. The Curve-billed Tinamou is generally common, but is not especially well known in terms of its life history, like the majority of tinamous. This reflects the fact that this tinamou is quite rarely seen, except when accidentally flushed. It breeds between January and August, and the eggs are chocolate brown, but very few other data are available concerning this high-altitude tinamou.