Conflicts hinder research into animal movements.

Satellite tracking has revolutionized our understanding of animal migration, yet its reliability increasingly depends on the geopolitical stability of the regions frequented by wildlife. Here, we show that military-induced interference with global navigation satellite systems (GNSS) during ongoing conflicts in Eastern Europe has severely compromised the accuracy of global positioning systems (GPS)-based tracking data for black-headed gulls (Chroicocephalus ridibundus). In 2024-2025, GPS trajectories revealed erratic, low-quality, and geographically implausible positions coinciding with known zones of electronic warfare. These inaccuracies hinder efforts to locate breeding colonies, identify key stopover habitats, and assess disease transmission risks posed by migratory birds, particularly for zoonoses such as highly pathogenic avian influenza (HPAI) H5N1. Our findings illustrate how modern conflicts now extend their impact into ecological research infrastructures, calling for systematic correction methods and international coordination to safeguard the robustness of movement ecology studies and One Health models in a geopolitically unstable world.