Safe, Simple, and Rapid: A Minimally Invasive Coding Technique for Identifying Individuals of the Endangered...

Individual identification is essential for wildlife population research but commonly relies on invasive methods that may negatively affect animal welfare. This study proposes a safe, simple, and rapid non-invasive identification method for the endangered Mongolian racerunner (Eremias argus) based on coding dorsal spot patterns. We documented 175 individuals using photographic data and assigned unique identification codes derived from two central longitudinal spot lines and overlapping spots, which capture individual-specific traits. No individuals were found to share identical codes during identification. Recaptured individuals showed stable spot patterns without any code changes, confirming the method's reliability for long-term monitoring. This approach requires only standard cameras or smartphones and is thus practical for field surveys and citizen science initiatives. The proposed method minimizes impacts on target species while maintaining high accuracy, offering a valuable alternative for ethical conservation and population studies.