Integrative multi-method survey for terrestrial vertebrate inventories

Biodiversity monitoring is critical for detecting environmental change, protecting threatened species, and guiding evidence-based conservation decisions. However, traditional approaches, such as direct observations, are often constrained by high labor demands, extended survey durations, and limited spatial coverage. To address these limitations, a large-scale, non-invasive assessment of terrestrial vertebrates was implemented in the Gaoligongshan National Nature Reserve, a biodiversity hotspot in southwestern China. This assessment integrated three independent detection techniques, including camera trapping, leech-derived invertebrate DNA (iDNA), and aquatic environmental DNA (eDNA) profiling, to maximize species detection and reduce method-specific biases. Collectively, the combined framework identified 102 wild terrestrial vertebrate species, including 60 mammals, 27 birds, 14 amphibians, and one reptile. Water eDNA achieved the broadest coverage, identifying 71 species (70% of the total), whereas both camera traps and leech iDNA each recorded 32 species. Only eight taxa were detected across all three platforms, reflecting their strong complementarity in capturing species assemblages. This multi-modal framework illustrates the effectiveness of integrating molecular and imaging-based approaches to produce high-resolution biodiversity inventories, thereby reinforcing the scientific basis for evaluating conservation outcomes and guiding the development of adaptive management strategies in complex ecosystems.