A Ground Surface Rolling Method for Detecting Environmental DNA of Terrestrial Animals

Biodiversity monitoring is essential for conservation and ecosystem management, but current terrestrial survey methods, such as visual observation, trapping, and camera traps, are labor‐intensive and time‐consuming. Environmental DNA (eDNA) analysis offers a non‐invasive alternative and is well‐established in aquatic systems, yet terrestrial eDNA methods remain underdeveloped. Existing terrestrial approaches, such as water or soil sampling and air filtration, face limitations in target coverage, DNA persistence, and ease of deployment. Surface‐swabbing techniques show promise but often lack scalability for frequent, multisite sampling. We aimed to develop and evaluate a simple, power‐free, and scalable terrestrial eDNA collection method capable of sampling wide ground‐surface areas for biodiversity monitoring. We designed the Koro‐rin sampler, consisting of a rotating body with a single‐use nonwoven fabric collector. This device collects surface‐associated particles (soil, leaf litter, and fine debris) from diverse substrates without a power source. Over 14 months, we collected 90 ground‐surface samples and 29 water samples from a drinking site within the same secondary forest in Japan. Samples were analyzed using MiBird and MiMammal metabarcoding, and results were compared with concurrent camera trap and seasonal observation data. Metabarcoding detected 53 bird and mammal taxa from ground and surface samples. Of these, 92% were also recorded by camera traps in front of the sampling areas, validating detection sensitivity. Seasonal patterns in eDNA detections matched the arrival timing of migratory birds observed visually. The method enabled high‐frequency, wide area sampling with minimal labor. The Koro‐rin sampler is a practical, sensitive, and time‐resolved approach for terrestrial eDNA monitoring. Its portability and disposability make it suitable for large‐scale, long‐term surveys. Combined with aquatic eDNA monitoring, it enables integrated ecosystem assessments.