Lessons from GPS-tagged Eurasian Curlews: synthesising movement ecology to inform conservation

Remote tracking of animals complements traditional marking and recapture methods across ecological studies, improving estimates of demographic rates, migration connectivity, habitat selection, and social interactions. Its insights into how individual behaviour scales up to population dynamics are especially critical for effective transnational conservation, particularly for threatened migratory species. Here, we synthesise over two decades of GPS tracking data from 626 Eurasian curlews ( Numenius arquata ) to assess how movement ecology informs conservation and policy for this species of high conservation concern across Europe. We show how tracking has refined our understanding of migration connectivity, demography, and habitat selection, and how it can be translated into actionable insights for conservation. Tracking data provided unprecedented information confirming strong site fidelity among adult curlews and evidence of local recruitment. It highlights the importance of young birds' survival until they become reproductively mature and recruit for the population dynamics, and therefore the need for appropriate conservation measures. At the same time, this review shows how movement data contributes to or can contribute to characterize most of the threats to curlews, such as human disturbance or the development of human infrastructure. These findings translate into policy recommendations, including habitat protection, network-based conservation of migratory nodes, mitigation of anthropogenic threats, and the strategic use of population reinforcement. Overall, this synthesis highlights the critical role of individual-based tracking in bridging ecological knowledge and conservation action and provides guidance for the future use of tracking data to improve the conservation status of the Eurasian Curlew along its flyway.