Distribution in the Americas
Darwin’s Nothura occurs from the highlands of central and southern Peru south through the Andes of Bolivia to northwestern and west central Argentina, south to Río Negro and northern Chubut.
In Peru Darwin's Nothura primarily occurs above 3800 m, but there is an isolated population at ca 1000 m in the arid central Urubamba Valley in Cuzco. The elevational range in Bolivia is 1500-4300 m (Hennessey et al. 2003).
Darwin’s Nothura occupies semiarid grasslands, savannas and open brushy country in central and western Argentina. Compared to its congener Spotted Nothura (Nothura maculosa), Darwin's Nothura occurs in areas with somewhat lower temperatures and rainfall, rougher topography, and sandier, less fertile soils (Bump and Bump 1969). In Peru and Bolivia, occurs in puna grassland.
Darwin's Nothura prefers areas rich in grass and forbs (Bump and Bump 1969). At one site in Argentina, Darwin’s Nothura occupied both natural grasslands and fields of alfalfa (Mosa 2004).