Distribution pattern, zoogeographic similarities and affinities of montane herpetofauna of Southern Eastern Ghats, peninsular India

We examined the distribution pattern, across-site similarities and zoogeographic affinities of amphibians and reptiles in the montane zones (> 900 m a.s.l.) of the Southern Eastern Ghats mountains in peninsular India. We deployed long-term field surveys in four select massifs namely Jawadi, Shevaroys, Kolli and Sirumalai and generated herpetofaunal species lists. Based solely on our species occurrence data, we identified taxa that characterise sites, site-pairs and site-clusters. We quantified the number of the various target taxa characterising each such Operational Geographic Unit. To infer faunal similarities, we performed cluster analysis using Jaccard’s similarity index. Our cluster diagram tree topologies differed between the various target taxa. The pooled data (amphibians, lizards and snakes) tree topology was similar to that of the lizard trees but the amphibianand snake-similarity trees were similar in their topologies. Our observations and analyses indicate that physical separation distance and intervening rivers between massifs decreased herpetofaunal similarity. To identify the zoogeographic affinities of range-restricted taxa, we segregated the species into classes, based on decreasing extent of their geographic ranges. Our analyses reveal that widespread species were predominant in this community even at high elevations, followed by Western Ghats dispersers, Eastern Ghats endemics (both presumed and confirmed), and lastly peninsular Indian and Sri Lankan elements.