Amphibians of the Kayan Mentarang National Park (East Kalimantan, Indonesia): estimating overall and local species richness

On the basis of surveys since 1997 and an intensive survey at the World Wildlife Fund field station at Lalut Birai in 2001, we assessed the importance of the Kayan Mentarang National Park in East Kalimantan for the conservation of Borneo's amphibian fauna. Sixty-five frog species and one Caecilian species are currently known to occur in this region. We report their occurrence in 16 subareas. Most of the species were recorded at Upper Bahau (41) and at the Lalut Birai field station (33). Based on the results of opportunistic searches and transect censuses at Lalut Birai, we argue that the amphibian diversity of the national park is still greatly underestimated.