Island‐restricted reptiles are more threatened but less studied than their mainland counterparts

Abstract Island ecosystems are disproportionately impacted by the ongoing Anthropocene defaunation. Although reptiles are unusually diverse on islands, and many require urgent conservation information, no overview of island‐restricted reptiles (IRRs) distribution, threat status, and research effort has been carried out. Here, we assessed the research allocation to IRRs, contrasted these patterns with their mainland counterparts, and evaluated the impact of morphological, geographical, and socioeconomic predictors on research effort. Furthermore, we identified species‐based research priorities based on the research outputs, threat status, and taxonomic distinctiveness. We found that although nearly one quarter of the planet's reptiles are IRRs and 30.1% are threatened, only 6.7% of the literature is devoted to IRRs and is biased towards a subset of few species. The Indo‐Malayan realm harbors the greatest diversity of IRRs. Larger and more widely distributed species attracted more studies. In contrast, more recently described species located at higher altitudes were less studied. Most top‐ranking reptile species in terms of research priority were IRRs. Overall, our findings suggest that current research levels are insufficient to inform evidence‐based conservation and emphasize the critical need to target research towards less known species and geographic regions.