Distribution

This species ranges along the Andes from extreme southern Ecuador, through Peru and Bolivia, and into northeast Chile and northwest Argentina. In Ecuador it is known only from a single site, in the Cordillera Las Lagunillas in southern Loja (Ridgely and Greenfield 2001); this is the northern known locality for subspecies stolzmanni. In Peru stolzmanni occurs south to Huánuco, northern Lima, and Pasco; the distribution is very local in the eastern Andes, and in the northern portions of the western Andes, but is continuous from southern Cajamarca south.

The distribution of Andean Hillstar is interrupted in central Peru by Black-breasted Hillstar (Oreotrochilus melanogaster). Black-breasted Hillstar is locally syntopic with stolzmanni (Zimmer 1951) in Pasco, central Peru. Black-breasted Hillstar is not known to meet the population of Andean Hillstar in south central Peru (nominate estella), but the potential contact zone also has not been surveyed intensively. The distribution of estella commences again, south of the known range of Black-breasted Hillstar, in Ayacucho, Apurímac, and Cuzco; and the distribution of the species continues south through Bolivia to northern Chile and northwestern Argentina (Fjeldså and Krabbe 1990, Jaramillo 2003).

The elevational distribution of Andean Hillstar in Peru is 3400–4600 m (locally as low as 3000 m) (Schulenberg et al. 2010); in Bolivia, it occurs at 2400-4800 m (Hennessey et al. 2003). Nonbreeding birds may descend at least as low as 2400 m (Fjeldså and Krabbe 1990), or perhaps even to 1800 m in Argentina (Johnson 1967).

Endemic to South America.

Restricted to the high Andes, Andean Hillstar is found in the arid temperate zone, on rocky slopes of watered, intermontane valleys, and in areas with isolated Polylepis forest. When nonbreeding, may descend to scrub or open woodlands of Andean valleys (Fjeldså and Krabbe 1990). Andean Hillstars frequently are observed in and around caves and mining tunnels, where they seek shelter from wind and cold temperatures. The high proportion of caves occupied by nesting hillstars (each of four "sea caves" at Lake Titicaca had a nest, and high proportions elsewhere) suggests that the number and distribution of these caves may be factors limiting local population sizes (Pearson 1953; also see Territorialty).

None described.

No information available.