A simple, robust, and inexpensive design for creating thermal refugia to protect amphibians from Batrachochytrium dendrobatidis in the field

Abstract The emergence and spread of wildlife diseases requires innovative, practical solutions to help vulnerable species survive in the wild. One promising approach involves exploiting mismatches in environmental tolerances between pathogens and their hosts to reduce disease impacts. Recent work, targeting a thermal mismatch between the amphibian‐killing fungal pathogen Batrachochytrium dendrobatidis ( Bd ) and the endangered green and golden bell frog ( Ranoidea aurea ), highlights the potential of this approach. In mesocosm experiments, solar‐heated “hotspot” shelters allowed infected R. aurea to elevate their body temperatures beyond Bd 's thermal limits, and thereby clear infections. Building on this, we optimized the design of such “hotspots” for long‐term field deployment and evaluated its performance in a cool‐climate region where severe Bd ‐driven amphibian declines have occurred. The improved shelters are cost‐effective, easily assembled, durable under field conditions, and consistently reach temperatures harmful to Bd while suitable for R. aurea and other frog species, even during mid‐winter when ambient temperatures were often below 10°C. This design represents a practical tool with the potential to mitigate Bd impacts in the wild.