The area forming this EBA is the high Andes of south-east Peru through to northern Argentina, together with the region's arid intermontane valleys which lie mainly in Bolivia. North to south, the EBA runs from Aricoma in the Cordillera de Carabay in Puno department of extreme south-east Peru, through Bolivia along the eastern side of the Andes east of Lake Titicaca, and along the Cordilleras Real and Cochabamba of the main Cordillera Oriental, then south along the Andes in northern Argentina through Jujuy, Tucumán, Salta, Catamarca, La Rioja, San Juan and Mendoza provinces. The EBA ranges in elevation from 1,100 m in the intermontane valleys to 4,600 m on the altiplano, and lies adjacent to the wet forests of the upper and lower yungas (EBAs 054, 055, 057). The Peruvian high Andes (EBA 051) to the north and west occupies similar altitude and climate zones.

The region tends to be dry at all altitudes and is cool and temperate in the high Andes (though there are occasional snowfalls and frosts) and warmer in the intermontane valleys. These differences result in a wide variety of vegetation types. Thus the high Andes part of the EBA conforms to the puna and pre-puna (transition) zones, the latter being between the puna and the humid temperate forest of the slopes. The puna zone is an open grassland without trees but with some low-lying scrub, and often including bare, rocky areas. The pre-puna zone is a complex mosaic of scrub dominated by tall columnar cacti with shrubs and small cacti forming the lower strata, areas of grassland with scattered trees, and open boggy grassland. Vegetation in the arid valleys consists mainly of arid scrub and columnar cacti. In semi-humid areas of the puna and pre-puna zones, and in the higher-altitude valleys, particularly along watercourses, there are patches of low-stature forest dominated by Polylepis.

Most of the restricted-range bird species are found in forested and scrub habitats within the puna and pre-puna zones, many of them occurring in Polylepis-dominated forest. A group of four restricted-range species (Ara rubrogenys, Upucerthia harterti, Lophospingus griseocristatus and Oreopsar bolivianus) is associated with the intermontane valleys: they occur mainly below 2,000 m, but-because their distributions vary and because other species from the higher Andes also range into these lower valleys, especially into the Polylepis forest-they are not considered to define a separate EBA; further information on the habitats and distributions of these species could, however, change this assessment in due course.

Recent surveys have recorded new locations and extended the known distributions of several restricted-range species such as Asthenes heterura, A. maculicauda, Idiopsar brachyurus and Saltator rufiventris in Tarija department of Bolivia (Fjeldså and Mayer 1996) and Oreotrochilus adela, A. heterura, Poospiza boliviana and Sicalis luteocephala in Argentina (Pearman 1989, Moschione and San Cristóbal 1993, Alvarez and Blendinger 1995). The Bolivian and Argentine parts of this EBA were treated separately in the original EBA analysis (ICBP 1992), but these Argentine records, new for the country, have meant that several of the species formerly believed to be restricted to the high Andes and intermontane valleys of Bolivia actually overlap with species endemic to northern Argentina's puna and pre-puna zones; these EBAs have thus now been combined.

Four species (Chalcostigma olivaceum, Cinclodes aricomae, Asthenes urubambensis and Anairetes alpinus) have only small parts of their ranges in the present EBA and are more widely distributed in the High Peruvian Andes (EBA 051). Three species (Metriopelia morenoi, Asthenes steinbachi and Poospiza baeri) are found only within the Argentine part of the EBA. Diglossa carbonaria is shared with the Bolivian and Peruvian upper yungas (EBA 055) because, as well as being found in arid montane scrub, it occurs in humid habitats such as the elfin forest which is associated with the yungas EBA.

The puna zone of Peru, Bolivia, Argentina, and Chile has been extensively altered for agriculture and is degraded in many areas through the grazing of domestic livestock, burning and the collection of firewood (Dinerstein et al. 1995). Settlement and agricultural conversion have already had dramatic effects on the EBA, and further expansion seriously threatens remaining fragments of habitat. The destruction of Polylepis forest through clearance for cultivation, firewood-collection and burning for pasture is a particularly serious threat to many of the restricted-range birds. Nine of them are considered threatened, and in the case of four (Cinclodes aricomae, Anairetes alpinus, Poospiza garleppi and Saltator rufiventris) this is because of destruction of their Polylepis forest habitat. A. berlepschi is threatened because of its tiny range (near Nevado Illampu). Ara rubrogenys, which is found in the arid foothills, has declined in its tiny range in Bolivia owing to capture for the cage-bird trade, persecution as a pest in peanut and maize fields, and loss of trees. Poospiza baeri is threatened because the grassland which surrounds its tiny range is susceptible to fire, which could in turn reach the species' specialized habitat in the ravines. Asthenes steinbachi appears to have been largely extirpated by habitat loss, remaining common only in a few scattered localities mainly in the southern part of its range, especially in Mendoza. Other more-widespread threatened species (all classified as Vulnerable) are found within the EBA, including Andean Flamingo Phoenicopterus andinus, Puna Flamingo P. jamesi, Horned Coot Fulica cornuta and White-tailed Shrike-tyrant Agriornis andicola.

Wege and Long (1995) list nine Key Areas in Bolivia for the threatened species found in this EBA, but only two of these have any protection: a small population of Ara rubrogenys occurred (at least formerly) on the edge of Amboró National Park (1,800 km²), and both Poospiza garleppi and Saltator rufiventris have been seen in Tunari National Park (60 km²). However, although none of the restricted-range species has yet been recorded from Bolivia's Madidi National Park and Integrated Management Area (19,000 km²), Remsen and Parker (1995) predict that eight will be found there when more biological surveys are carried out.

There are a number of key protected areas in Argentina overlapping with the EBA, several of which are known to hold the restricted-range species. These include El Leoncito Strict Nature Reserve (740 km²), Calilegua National Park (760 km²), Pozuelos Biosphere Reserve (3,640 km²) and Potrero de Yala Provincial Park (43 km²). Importantly, there is a proposal to gazette most of the Sierra de Aconquija within the Campo de los Alisos National Park (2,500 km²) (Halloy et al. 1994) which would secure protection for several of the restricted-range species found only in the Argentine part of this EBA (as well as most species in the adjacent Argentine and Bolivian yungas, EBA 057).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Bolivian and Argentine high Andes. Downloaded from https://datazone.birdlife.org/eba/factsheet/59 on 22/11/2024.