Multi-modal, interrelated navigation in migratory birds: a data mining study

Understanding how long-distance migratory birds navigate remains challenging, particularly in how they integrate multiple environmental cues. Traditional studies, primarily based on laboratory experiments and displacement studies, may not capture the complexity of navigation in the wild. In this study, we applied a data mining approach to investigate the navigational strategies of greater white-fronted geese (Anser albifrons) during their annual migrations between the Arctic and central Europe. We integrated a decade of tracking data from 117 individuals with high-resolution geomagnetic data (including solar-wind–induced variations), wind conditions, and a potential visual cue. Hierarchical cluster analysis revealed multi-modal and interrelated navigation strategies that flexibly adapted to environmental conditions such as wind, diurnal cycles, and flock-specific dynamics. Under favourable tailwinds, geese maintained stable headings with minimal changes in geomagnetic heading and apparent angle of geomagnetic inclination, consistent with both geomagnetic loxodrome and magnetoclinic routes, enabling efficient flights towards stopovers or simultaneously towards stopovers and final destinations. Geese also appeared to combine visual landmarks with geomagnetic information, adjusting their reliance on landmarks between day and night. Our findings highlight the complexity and adaptability of avian navigation and emphasise the role of multi-modal sensory integration and environmental context in shaping migratory decisions.