The climate and vegetation of Sri Lanka are greatly influenced by the ranges of mountains which rise to 2,518 m in the south of the island. The south-western quarter of the island receives very heavy rainfall, and the natural vegetation below c.900 m is tropical lowland evergreen rain forest, although much of this has now been cleared. Tropical montane rain forest occurs above this altitude, with areas of wet temperate forest and montane grassland at the greatest heights. This part of the island is often referred to as the wet zone (including the montane habitats, which are sometimes described separately as the hill zone) and most of the remainder of the island as the dry zone. There is also an intermediate zone between the wet and dry zones, formed by a band of tropical semi-evergreen rain forest which bounds the tropical evergreen rain forest block in the south-west. The dry zone receives lower, more seasonal rainfall, and the vegetation here includes monsoon forest (principally tropical dry evergreen forest) and the savannas and grasslands which are derived from them by clearance and repeated burning (Champion and Seth 1968, Crusz 1984, Ratnapala 1984, Whitmore 1984).

Twenty-three restricted-range species are confined to this EBA, more than any other EBA in this region. All are forest birds, but they can be subdivided into several groups with distinct habitat requirements. Two species are confined to the lowland evergreen rain forests of the wet zone below c.900 m, and six to the montane habitats of the hill zone above this altitude. A further six species are confined to the rain forests of the wet zone (including the hill zone) in the lowlands and the mountains, although Garrulax cinereifrons is mainly found in the lowlands and Sturnus albofrontatus at intermediate altitudes in the foothills. The remaining nine species are more widespread, although only three of them occur widely in the dry zone. Outside the wet zone, the other six appear to range only into the semi-evergreen forests of the intermediate zone and riverine forests in the dry zone (S. Kotagama, p. xxxi in Legge 1983). The lowland rain forests and montane forests in the south-west of Sri Lanka are therefore by far the most important habitats of the EBA.

Sri Lanka has suffered rapid forest loss and degradation in the past 40 years, largely to meet the demands of an expanding population. The major causes of deforestation include the gathering of fuelwood, clearance of forest for permanent agriculture, shifting cultivation, replacement of natural forest by tree plantations, fire, urbanization and timber felling. Natural closed-canopy forest is estimated to have declined in extent from 29,000 km^>2 (44% of the island's land area) in 1956 to 12,260 km² in 1983, of which only 1,440 km² was rain forest (Collins et al. 1991). It is feared that the forest loss will continue, as the existing forest conservation laws have proved to be ineffective, and emergency regulations have had to be declared to halt illegal logging (Anon. 1992b).

Many of the island's restricted-range birds are adaptable to man-modified habitats and remain common. Six species, however, are listed as threatened because they appear to be confined to closed-canopy forests and are therefore vulnerable to forest loss within their small ranges. Another threatened restricted-range species, Kashmir Flycatcher Ficedula subrubra, breeds in the Western Himalayas (EBA 128) and winters in montane forest in Sri Lanka and the Western Ghats (EBA 123). More widespread threatened species which occur on Sri Lanka are Spot-billed Pelican Pelecanus philippensis and Lesser Adjutant Leptoptilos javanicus (both classified as Vulnerable), wetland birds which do not occur in the same habitats as the restricted-range species.

IUCN (1990, 1992c) lists 67 protected areas for Sri Lanka, but most of these are in the dry zone and only contain suitable habitat for a few of the restricted-range species. The most important reserves for the majority of them are Sinharaja National Heritage Wilderness Area, Peak Wilderness Sanctuary, Horton Plains National Park and Hakgala Strict Nature Reserve. Together, these areas include the largest remaining areas of lowland and montane rain forest in Sri Lanka's wet zone, although many remnant patches of forest are unprotected. Uda Walawe National Park in the intermediate zone also supports several of the restricted-range species (IUCN 1990). Green and Gunawardena (1993) describe a current project to evaluate the conservation importance of remaining natural forests, with the aim of identifying an optimum network of conservation areas to protect forest biodiversity and important watersheds.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Sri Lanka. Downloaded from https://datazone.birdlife.org/eba/factsheet/126 on 22/11/2024.