A Threat‐Scoring Framework Using Crowdsourced Data Indicates High Threat Levels in Fossorial Shieldtail Snakes

ABSTRACT Mapping species distributions with precision is fundamental to identifying their conservation needs. The International Union for Conservation of Nature (IUCN) predominantly uses geographic ranges to assign threat categories. Range maps for these assessments are often drawn from expert knowledge, but their accuracy is seldom evaluated for most taxa, particularly those that are rare and poorly studied. Using shieldtails, a group of small fossorial snakes, we demonstrate a framework for mapping distributions and evaluating threats in peninsular India. Of the 74 known shieldtail species, IUCN has evaluated only 56, with many categorised as ‘Data Deficient’. To address this gap, we initiated the Shieldtail Mapping Project, a citizen science project to collect data on Indian shieldtails. By integrating citizen science observations, published literature and field and museum records, we generated geographic ranges for 12 species. We compared them to those from IUCN and the Global Assessment of Reptile Distributions (GARD). We also assessed threat exposure using three indicators: the proportion of range outside protected areas, increases in built‐up areas and tree‐cover loss. Critically, we found both large differences in range sizes and low range overlap between our range polygons and expert‐drawn maps. Our threat exposure metric revealed high threat levels and increased risk for several shieldtail species. Overall, we demonstrate the utility of citizen science projects in effectively gathering distribution data on rare taxa and provide a framework for data‐driven approaches to assess species threats.