Conservation and distribution status of amphibian fauna in Sri Lanka

Abstract

Sri Lanka has an exceptionally rich amphibian biodiversity with high endemism. This paper describes 106 amphibian species, the majority confined to rainforests and many threatened with extinction. The key factors causing amphibian decline in Sri Lanka are of anthropogenic origins; habitat destruction and fragmentation, alien invasive species, wildlife diseases/pathogens, climate change and environmental pollution. Only 750 km2 of Sri Lanka are covered with tropical rainforests and this area is broken into 100 km2 fragments or less. It is difficult for amphibians to tolerate disturbances and to maintain a sustainable population size under these conditions. Alien and domestic species impose threats by direct predation, competition, disease contraction and habitat alteration. Parasites and pathogens, especially the chirtrid fungus, hamper the growth, reproductive success, and physical fitness of amphibians and can result in mortality. Climate change has reduced the distribution of amphibians by modifying vegetation and habitat structure rendering them unsuitable for some amphibians. Pollution, especially agro-chemicals, threaten amphibians causing anatomical malformations, physiological disorders and even mass mortalities. Furthermore, acid depositions causing diebacks in montane forests also destroy amphibian niches. This paper recommends a number of conservation initiatives including in-situ and ex-situ conservation, the establishment of buffer zones to protect core forests, promotion of research on biodiversity conservation, improvement of conservation policies and legal frameworks as well as community-based activities including raising public awareness, environmental education and the introduction of eco-friendly agricultural practices