Herpetofaunal diversity of West Bali National Park, Indonesia with identification of indicator species for long-term monitoring

We report on the results of a survey of the herpetofauna of West Bali National Park (Taman Nasional Bali Barat in Indonesian, hereafter TNBB) that was carried out in 2015. The survey also included other taxa and the motivation for it was to identify a species or group of species that could be used as indicators of management success for Protected Area Credits (PAC) under the Rainforest Standards (RFS™) system. Four major ecosystems, moist forest, deciduous monsoon forest, savanna and an abandoned Teak plantation, were sampled over a period of 10 days, using belt transects and pitfall traps. We measured species richness, abundance and density, herpetofaunal diversity (Simpson’s Index of Dominance and the Shannon Weiner Index) and community similarity. We also estimated the indicator value to determine which species, if any, might be suitable as indicators of environmental conditions. The survey yielded 30 species, 12 frogs and toads, 7 snakes and 11 lizards. Out of them there is an endangered gecko, Cyrtodactylus jatnai, a vulnerable frog, Microhyla orientalis, and a vulnerable tree-skink, Cryptoblepharus baliensis. Diversity was highest in the moist forest, followed closely by both the deciduous forest and the savanna. The greatest abundance was found in the savanna, followed by the moist forest and then the deciduous forest. Both diversity and abundance were extremely low in the abandoned teak plantation. Eleven species were identified as potential indicators of environmental deterioration if their numbers were to decrease. Frogs and toads were the best indicators in the moist forest, while lizards were the most suitable indicators for savanna and deciduous forest. No snakes were identified as indicators. It is concluded that herpetofauna can be useful and cost-effective indicators of environmental change.