Mapping the Missing: Assessing Amphibian Sampling Completeness and Overlap With Global Protected Areas

The aim of the study was to assess amphibian sampling completeness and the overlap of sampling completeness categories with natural protected areas (NPAs) and key biodiversity areas (KBAs) at global scale. We evaluated amphibian sampling completeness across six of the earth's eight biogeographic realms to identify well-sampled, under-sampled, and data-gap areas in the context of global amphibian distribution. Additionally, we examined the spatial overlap of each sampling category with NPAs and KBAs. The Nearctic and Australasian realms had the highest number of records and well-sampled areas. Significant data gaps were identified, particularly in the Afrotropical, Indo-Malayan, Neotropical, and Palearctic realms. We found low levels of spatial match (< 35%) between classified areas and NPAs/KBAs. Amphibian distribution data are largely incomplete, with the most extensive gaps in the most species-rich realms: Neotropic, Indo-Malayan, and Afrotropical. The low overlap between under-sampled and data-gap areas with NPAs and KBAs suggests that these regions, critical for amphibian diversity, are insufficiently represented within established conservation priorities. Given the urgent threats to biodiversity from global change, rapid responses are essential to enhance our understanding of species distributions and community structures in amphibians. This study provides spatial insights to help identify key data-gap areas for amphibian research and conservation prioritization.