Seasonal Differences in Migration Routes and Stopover Use of Greater Sand Plovers Between Mongolia and the Beibu Gulf Revealed by GPS Tracking

ABSTRACT

Seasonal migration strategies can vary with life history demands and environmental context, yet such contrasts remain poorly documented for many shorebirds along the East Asian–Australasian Flyway (EAAF). We used high‐resolution GPS‐GSM tracking of 11 adult Greater Sand Plovers ( Charadrius leschenaultii ) tagged in the Beibu Gulf, China, during 2021–2022 to quantify and compare their spring (northbound; 12 tracks) and autumn (southbound; 8 tracks) migrations between nonbreeding areas in the northern South China Sea and breeding grounds in Mongolia. Spring movements followed predominantly inland corridors and were relatively direct, with journeys of approximately 3300 km completed in about 2 weeks. During spring migration, birds spent just over half of the total migration period at generally short but more frequent stopovers. In contrast, autumn movements occurred mainly along coastal pathways and covered around 4100 km over nearly 4 weeks. Across seasons, tracked individuals converged on the Beibu Gulf, which functioned both as an important stopover bottleneck and as a nonbreeding endpoint for part of the tracked population. These tracking data indicate seasonal differences in route use, stopover allocation, and habitat use, with spring movements showing a higher travel‐to‐stopover ratio and autumn movements involving a greater proportion of time at stopovers, suggesting greater refueling investment. Given the limited sample size and number of complete annual tracks, these inferences should be treated as preliminary. Nevertheless, the results highlight the potential importance of conserving both inland wetlands and coastal intertidal habitats along the EAAF.