With 90 recognized species, kukri snakes in the genus Oligodon Fitzinger constitute the second largest snake radiation in the world. Oligodon species are collectively distributed across the Asian continent and possess several ecological and morphological attributes that are unique amongst other snakes. Despite their high levels of species richness, evolutionary relationships within Oligodon are poorly understood due to a limited number of samples and genetic markers available in earlier phylogenies. In this study, we assembled the largest molecular dataset of Oligodon to date, which we use to assess the systematics and biogeography of the entire genus. Based on a combination of maximum likelihood and Bayesian phylogenies using fragments of three mitochondrial genes (12 s, 16 s, CytB) and three nuclear genes (Rag1, C-mos, BDNF), we identify eight deeply divergent clades within Oligodon, of which only two correspond with species groupings that were recognized by previous morphological classifications. Four species delimitation methods employed on the mitochondrial portion of the dataset resulted in dramatically divergent estimations of molecular operational taxonomic units (mOTUs). When combined, all four methods support the existence of unrecognized species-level lineages, but also indicate that several other Oligodon species are poorly differentiated genetically and require additional integrative taxonomic research to properly resolve. Based on divergence dating, we demonstrate that Oligodon began to diversify during the early Neogene and hypothesize that the most recent common ancestor of the genus originated in mainland Southeast Asia. We conclude by recognizing eight phylogenetically defined species groups and identify sampling gaps that require further investigation once new data becomes available. This study contributes to a greater understanding of snake evolution on the Asian continent and acts as a baseline for future studies of this speciose genus.
Protected Areas (PAs) are the cornerstone of biodiversity conservation. Here, we collated distributional data for >14,000 (~70% of) species of amphibians and reptiles (herpetofauna) to perform a global assessment of the conservation effectiveness of PAs using species distribution models. Our analyses reveal that >91% of herpetofauna species are currently distributed in PAs, and that this proportion will remain unaltered under future climate change. Indeed, loss of species' distributional ranges will be lower inside PAs than outside them. Therefore, the proportion of effectively protected species is predicted to increase. However, over 7.8% of species currently occur outside PAs, and large spatial conservation gaps remain, mainly across tropical and subtropical moist broadleaf forests, and across non-high-income countries. We also predict that more than 300 amphibian and 500 reptile species may go extinct under climate change over the course of the ongoing century. Our study highlights the importance of PAs in providing herpetofauna with refuge from climate change, and suggests ways to optimize PAs to better conserve biodiversity worldwide.