Biodiversity in Sri Lanka and the Western Ghats.

WE READ WITH INTEREST THE REPORT “LOCAL endemism within the Western Ghats–Sri Lanka biodiversity hotspot” by F. Bossuyt et al. (15 Oct. 2004, p. 479), which documents patterns of diversification in selected vertebrate and invertebrate lineages from Sri Lanka and the Western Ghats region of western India. Although these two areas have long been united as a single biogeographic unit (1), and more recently as a biodiversity “hotspot” (2), Bossuyt et al. highlight the distinctive faunal histories of the two regions and caution against treating them as a single unit for conservation purposes. We would like to add two comments, which support and extend their results. First, the respective bird and mammal faunas of Sri Lanka and the Western Ghats are distinct in many ways: There are marked differences in the regions’ restricted-range mammal assemblages [the Western Ghats support at least 15 endemic mammal species; Sri Lanka supports at least 13 endemic species, and because they share few restricted-range birds, they are treated as separate “Endemic Bird Areas” (3)]. This is significant because it is birds and mammals that tend to act as “flagship species” for conservation. Second, trenchant faunal differentiation is evident within both areas, especially in different climatic zones within Sri Lanka (4, 5), and the two regions can be subdivided into multiple “ecoregions” (6). There may sometimes be stronger faunal differentiation between wet, dry, and cloud forest zones within Sri Lanka than between that island’s dry zone and the dry country of South India [e.g., (4)]. Lists of mammals restricted to Sri Lanka, the Western Ghats, or the hotspot as a whole are given in (7–10). Those apparently restricted to high-altitude cloud forest zones (marked with an asterisk) comprise all endemic genera, half of Sri Lankan endemics, one-third of Western Ghats endemics, and about one-third of mammal species endemic to the hotspot as a whole. KRISTOFER M. HELGEN1 AND COLIN P. GROVES2 1School of Earth and Environmental Sciences, University of Adelaide,Adelaide, SA 5005,Australia. E-mail: [email protected]. 2School of Archaeology and Anthropology, Australian National University, Canberra, ACT 0200, Australia. E-mail: [email protected]