Bolivian and Argentine yungas

Country/Territory Argentina; Bolivia
Area 60,000 km2
Altitude 800 - 3400 m
Priority urgent
Habitat loss moderate
Knowledge incomplete

General characteristics

The yungas region essentially refers to the eastern slope of the Andes of extreme south-east Peru, Bolivia and Argentina. This particular EBA extends from Chuquisaca department of Bolivia, south through Tarija and the Argentine provinces of Jujuy, Salta, Tucumán, Catamarca and La Rioja. The altitude ranges from 800 m in the foothills up to 2,500 m, but sometimes reaches as high as 3,100 m. The northern end of the EBA is on the southern slope of the Cordillera Oriental of Bolivia, which branches out from the main Andean range running west to east. The northern slope of the Cordillera Oriental abuts the southern end of the Bolivian and Peruvian lower yungas (EBA 054). Adjacent to this EBA is the bottom end of the southern High Andes of Bolivia and Argentina (EBA 056 in part).

The climate is wet and humid with over 2,500 mm of rain annually brought along northerly trade winds. Correspondingly the vegetation consists of various evergreen forest formations, all of them with canopy heights not usually over 15 m. At higher altitudes, mainly between 1,200 m and 2,500 m, the forest is dominated by Andean alder Alnus acuminata, Podocarpus or pines. At lower altitudes these species are admixed with other trees, especially from the families Lauraceae and Myrtaceae.

Restricted-range species

The restricted-range bird species occur largely in the humid forests of the EBA, of which alder forest is especially important for Amazona tucumana and Cinclus schulzi, the latter being found always along fast-flowing streams in these forests. Atlapetes citrinellus shows the broadest habitat requirements, being found in hedgerows in agricultural areas, dense scrub and burnt forest as well as in coniferous and humid forests. C. schulzi winters at lower altitudes (to 800 m), and A. tucamana in other forests as low as 300 m. Elaenia strepera is an austral migrant, breeding only in this EBA and apparently wintering 3,000 km to the north in Venezuela (Marantz and Remsen 1991).

Species IUCN Red List category
Red-faced Guan (Penelope dabbenei) LC
Rothschild's Swift (Cypseloides rothschildi) LC
Blue-capped Puffleg (Eriocnemis glaucopoides) LC
Tucuman Amazon (Amazona tucumana) VU
White-throated Antpitta (Grallaria albigula) LC
Zimmer's Tapaculo (Scytalopus zimmeri) LC
White-browed Tapaculo (Scytalopus superciliaris) LC
Slaty Elaenia (Elaenia strepera) LC
Rufous-throated Dipper (Cinclus schulzii) VU
Yellow-striped Brush-finch (Atlapetes citrinellus) LC

Important Bird & Biodiversity Areas (IBAs)
Country IBA Name IBA Book Code
Argentina Abra Grande AR038
Argentina Acambuco AR027
Argentina Alto Calilegua AR011
Argentina Cerro Negro de San Antonio AR025
Argentina Cuesta de las Higuerillas AR078
Argentina Cuesta del Clavillo AR094
Argentina Cuesta del Obispo AR050
Argentina Cuesta del Totoral AR080
Argentina El Fuerte y Santa Clara AR024
Argentina Fincas Santiago y San Andrés AR037
Argentina Itiyuro-Tuyunti AR028
Argentina La Cornisa AR026
Argentina Lagunas San Miguel y El Sauce AR018
Argentina Palomitas y Ebro AR046
Argentina Pampichuela AR012
Argentina Parque Nacional Baritú AR033
Argentina Parque Nacional Calilegua AR015
Argentina Parque Nacional Campo de los Alisos AR093
Argentina Parque Nacional El Rey AR045
Argentina Parque Provincial La Florida AR092
Argentina Parque Provincial Laguna Pintascayoc AR034
Argentina Parque Provincial Los Ñuñorcos y Reserva Natural Quebrada del Portugués AR090
Argentina Reserva Natural Las Lancitas AR021
Argentina Reserva Provincial Santa Ana AR095
Argentina Río Los Sosa AR091
Argentina Río Santa María AR039
Argentina Río Seco AR031
Argentina San Francisco-Río Jordan AR014
Argentina Santa Victoria, Cañani y Cayotal AR030
Argentina Sierra de San Javier AR087
Argentina Sierra de Zapla AR023
Argentina Tiraxi y Las Capillas AR020
Argentina Trancas AR083
Argentina Yala AR022
Argentina Yuto y Vinalito AR016
Bolivia Reserva Biológica Cordillera de Sama BO021
Bolivia Reserva Nacional de Flora y Fauna Tariquía BO042
Bolivia Serranía de Aguarague BO046

Threat and conservation

It has been estimated that as much as 60% of the forest in the yungas of Argentina has disappeared (Vervoorst 1979). There are no estimates for the Bolivian part of the EBA, but recent ornithological surveys (e.g. Fjeldså and Mayer 1996, Tyler and Tyler 1996) have noted large areas of degraded land within the humid yungas-though there are also extensive forests remaining such as a 1,300 km2 tract between the Pilcamayo and Pilaya rivers in Montes Chapeados. Natural forests in Argentina have disappeared mainly through logging of valuable woods, conversion for agriculture, and plantations of exotic pines Pinus; road-building, human colonization and uncontrolled tourism have further increased habitat destruction (WWF/IUCN 1997).

The alder forest zone is especially important for the threatened Cinclus schulzi; its riverine habitat is endangered by reservoir construction, hydroelectric and irrigation schemes, eutrophication, deforestation and stock-grazing (Tyler and Tyler 1996).

There are a number of protected areas overlapping with the EBA, several of which are known to hold the restricted-range birds. These include Tariquía National Reserve (2,469 km2) in Bolivia, and Calilegua National Park (760 km<+>), Baritú National Park (724 km2), El Rey National Park (442 km2) and Potrero de Yala Provincial Park (43 km2) in Argentina. Importantly, there is a proposal currently being considered by Tucumán provincial government in Argentina to create the Campo de los Alisos National Park (2,500 km2), which would cover much of the Sierra de Aconquija (Halloy et al. 1994). This national park would secure protection for populations of all the restricted-range species of this EBA (as well as several species from the High Andes of Bolivia and Argentina, EBA 056).

Recommended citation
BirdLife International (2024) Endemic Bird Areas factsheet: Bolivian and Argentine yungas. Downloaded from https://datazone.birdlife.org/eba/factsheet/75 on 24/02/2024.