Identifying global hotspots and conservation priorities for reptilian phylogenetic diversity

Abstract

As we face the current extinction crisis with extremely limited resources for conservation, it is important to consider how we can preserve as much of the tree of life as possible. To date, global assessments of phylogenetic conservation priorities have been conducted for amphibians, birds and mammals. However, a lack of data has previously precluded the incorporation of reptiles-which represent almost a third of terrestrial vertebrate diversity-into such analyses. Here, we present the first global analysis of reptilian phylogenetic conservation priorities. As reptiles are not comprehensively assessed by the IUCN Red List, we employ a combination of species-focused and spatial approaches to identify priorities at both scales. We use an EDGE approach to identify reptile lineages which represent a disproportionate amount of unique evolutionary history and are threatened with extinction. Using species range distributions and phylogenetic datasets for almost all described reptile species, we highlight global hotspots of imperilled reptilian Phylogenetic Diversity (PD) using a combination of established and novel approaches (e.g. Phylogenetic Endemism and Evolutionary Distinctness Rarity). We also introduce a method for prioritising regions for conservation of threatened PD which can account for both threats that affect all species in a geographic region (such as habitat destruction) and threats that affect a species in all regions (such as targeted hunting). Finally, we identify priority regions with imperilled reptilian PD and poor coverage of protected areas, which include Caribbean islands, Madagascar and the Philippines. Our work highlights the need for additional conservation actions to effectively conserve the reptilian tree of life into the future.