The East Andes run almost the length of Colombia, taking in the Sierra de Perijá which sits astride the border with Venezuela, the Páramo de Tamá which extends just into Venezuela where the East Andes abuts the Cordillera de Mérida (EBA 034; the two being separated by the Táchira depression, i.e. the Torbes and Quinimari valleys), and the main Andean chain to just north of Neiva near the head of the Magdalena valley. The head of the Magdalena valley and the southernmost end of the East Andes south of Neiva form part of the Colombian inter-Andean slopes (EBA 040).

Covering a wide altitudinal range, this EBA supports diverse vegetation including large expanses of páramo, dry temperate scrub and woodland, humid elfin forest and humid subtropical forest typical of lower mountain slopes. The western slope, between 1,500 and 2,500 m, historically supported humid subtropical and temperate oak-Lauraceae forest, with oak-dominated forest characteristic of higher altitudes. Also on the western slope are areas of upper tropical, dense, dry Acacia scrub and numerous bushy canyons (Wege and Long 1995). The Bogotá and Ubaté savannas (at 2,600 m), Laguna de Tota and a number of other high-altitude lakes once supported a diverse range of wetland and marsh habitats that have now all but been destroyed (see 'Threats and conservation', below).

The restricted-range birds occupy the full range of habitat-types from the upper tropical to temperate and páramo zones: the lakes and marshland of the central plateau (and páramo fens) are inhabited by the threatened Rallus semiplumbeus and Cistothorus apolinari, and were home to Podiceps andinus before its recent extinction (Collar et al. 1992); the páramo zone (and the ecotone with elfin forest) is inhabited by Chalcostigma heteropogon, Oxypogon guerinii and Schizoeaca perijana; and the majority of the remaining species can be found in humid forest or open/secondary habitats. The lakes and marshland of the central plateau (and páramo fens) form a severely threatened ecosystem and a well-defined smaller area of endemism; as well as its wetland specialists, it harbours endemic subspecies such as Yellow-billed Pintail Anas georgica nicefori, Ruddy Duck Oxyura jamaicensis andina, Spot-flanked Gallinule Gallinula melanops bogotensis, Bearded Tachuri Polystictus pectoralis bogotensis and Yellow-hooded Blackbird Agelaius icterocephalus bogotensis (Fjeldså and Krabbe 1990, Collar and Wege 1995).

The most interesting distributional patterns shown by species in this EBA belong to the suite of species known only from the Páramo de Tamá massif on the Colombia-Venezuela border: Grallaria chthonia is known only from Hacienda La Providencia near the source of the Chiquita river on the Venezuelan side of this massif; Grallaricula cucullata is found in the Colombian inter-Andean slopes (EBA 040), but within the East Andes is known only from the Páramo de Tamá in Venezuela, as a distinct subspecies venezuelana; and Odontophorus columbianus is primarily confined to the Cordillera de la Costa Central (EBA 033), with a disjunct population known from the Chiquita river in the present EBA (Meyer de Schauensee and Phelps 1978, Collar et al. 1992). The area either side of the Táchira depression warrants further research, as the distributions of species in this region where the East Andes and Cordillera de Mérida (EBA 034) meet are poorly understood; Táchira Emerald Amazilia distans, for example, is known from just five (apparent) observations since its discovery in 1954, in an area which in places is just c.30 km distant from the Páramo de Tamá (and therefore perhaps occurring in this EBA too). Both Metallura iracunda and Schizoeaca perijana are endemic to the Sierra de Perijá at the northernmost end of the EBA, and Clytoctantes alixii and Grallaria excelsa are present only in the sierra and adjacent EBAs. Grallaria kaestneri and Thryothorus nicefori are presently known from just one locality each, on opposite slopes of the East Andes. Distributions at the south-westernmost end of the EBA (where the East Andes join the Central Andean chain) are poorly known, and restricted-range species from this EBA (e.g. Chlorostilbon poortmani) at times overlap with those from the inter-Andean slopes (EBA 040).

Amethyst-throated Sunangel Heliangelus amethysticollis clarissae, which has sometimes been considered a separate species, is confined to this EBA and the Cordillera de Mérida (EBA 034) (Fjeldså and Krabbe 1990, J. Fjeldså in litt. 1993).

The forests and marshlands of the Colombian East Andes have been subjected to extensive degradation (Forero 1989, Collar et al. 1992), with progressive deforestation on the lower slopes, i.e. the lower montane humid forest (Wege and Long 1995). On the western slopes, the humid subtropical and temperate (primarily oak) forest at 1,500-2,500 m has been largely cleared for intensive crop cultivation and pastureland, although important fragments do still remain (see below). Even the dense, dry Acacia scrub that was the dominant vegetation along the Fonce river in the upper tropical zone on the western slope has been lost to widespread agriculture such as coffee plantations, pasture and arable. On the eastern side, the forest that once surrounded Laguna de Tota (at c.3,000 m) is now almost totally gone, and the fringing wetland habitat is extensively reduced. Introduced fish, intensive agriculture, pollution and sediment run-off have caused serious problems to the lake community. Most of the lakes on the Bogotá and Ubaté savannas have been subjected to similar problems. The potential exploitation of coal concessions threatens the subtropical forest in a portion of Venezuela's El Tamá National Park. The Sierra de Perijá is being rapidly deforested on the Venezuelan side: from the bottom up for cattle-ranching, and from the top down for narcotics cultivation. There is no active management of Sierra de Perijá National Park and its future is uncertain, particularly as there are Venezuelan government proposals for coal-mining within its boundaries (C. J. Sharpe in litt. 1997).

Fourteen of the restricted-range birds in this area are threatened (and a further seven are Near Threatened), primarily due to the extensive loss of forest cover and the destruction of wetland habitats throughout the mountain chain. The severe degradation of the marshes and lake ecosystems is shown by the fact that Podiceps andinus is now considered extinct (300 individuals were reported on Laguna de Tota as recently as 1968), with the endemic subspecies of Yellow-billed Pintail Anas georgica nicefori almost certainly gone (Fjeldså and Krabbe 1990). A number of the threatened birds are very poorly known, with three species (see 'Restricted-range species', above) recorded from just one locality (these include Grallaria chthonia, which has not been recorded since 1956) and Amazilia castaneiventris known from only five localities and just one record since the 1960s (Collar et al. 1992). The widespread but threatened Yellow-eared Parrot Ognorhynchus icterotis and Red Siskin Carduelis cucullata also occur in this EBA, and similarly are threatened due to loss of their forest habitat - and also, in the case of C. cucullata, by the cage-bird trade.

Nine of the 24 Key Areas for the threatened birds in this EBA (Wege and Long 1995) currently have some form of protected status. In Venezuela, two important protected areas (which correspond to the two Key Areas in that country) are the Sierra de Perijá and El Tamá National Parks, the latter being contiguous with Tamá National Park in Colombia. Other important protected areas in Colombia (which are primarily centred on the higher-altitude sites) include: Chingaza National Park (and the adjacent Río Blanco-Olivares Forest Reserve and Carpanta Biological Reserve), El Cocuy National Park, Pisba National Park and Sumapaz National Park (Hernández Camacho et al. undated). The Guanentá-Alto Río Fonce Fauna and Flora Sanctuary on the western slope of the East Andes protects the only sizeable forest tract remaining in the area (humid subtropical and temperate oak forest).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Colombian East Andes. Downloaded from https://datazone.birdlife.org/eba/factsheet/38 on 22/11/2024.