Spatially Replicated eDNA Metabarcoding Detects Conservation‐Priority Migratory Waterbirds and Reveals Zone‐Level Community Differentiation at Baima Lake, a Ramsar Wetland in Eastern China

ABSTRACT

Environmental DNA (eDNA) metabarcoding offers a non‐invasive approach to wetland bird community monitoring, yet its capacity to detect conservation‐priority migratory species at stopover wetlands with no prior systematic baseline remains largely untested. We conducted the first spatially replicated eDNA survey at Baima Lake Wetland (Huai'an, China), a Ramsar site designated in 2023 and an important stopover along the East Asian–Australasian Flyway. We sampled 24 sites across three habitat zones during spring migration (March 2024) and the post‐breeding period (September 2024) using the 12SV05 primer targeting the mitochondrial 12S rRNA gene. eDNA detected 49 bird species, including four absent from the published checklist of Baima Lake. Most notably, Baer's Pochard ( Aythya baeri ; CR, IUCN) and the Oriental Stork ( Ciconia boyciana ; EN, IUCN), both globally threatened migratory visitors, were detected exclusively in spring at 25% and 8% of sites respectively, illustrating the value of eDNA temporal persistence for capturing evidence of brief stopover events. Despite non‐significant alpha diversity differences among zones, community composition differed significantly (PERMANOVA: R ²  = 0.48–0.52, p  ≤ 0.03), with only 2 of 162 OTUs shared across all three lake zones. These findings establish the first molecular avian biodiversity baseline for Baima Lake and demonstrate that spring eDNA surveys can systematically document conservation‐priority migratory species and reveal fine‐scale zone‐level community differentiation at inland Ramsar wetlands, complementing traditional and camera‐based monitoring approaches where they are most limited.