During migration, birds cross considerable geographical barriers, experience changing weather conditions, and face unfamiliar environments with unpredictable resource availability and predation pressure. Consequently, most aspects of long-distance bird migration are expected to be under optimization pressure, given the high costs resulting from non-optimized behavior (Alerstam and Lindström, 1990). In addition to evolutionary adaptations and innate programs, migration requires behavioral flexibility (Åkesson and Helm, 2020), where individuals need to make decisions about landing, departing, flight directions, altitudes, general route, stopover choices, and predator and pathogen avoidance (Klinner et al., 2020; Sabal et al., 2021). Although some aspects of optimal migration have been criticized (e.g., Chernetsov, 2012), the theory serves as an essential framework for understanding the ecology and evolution of bird migration. Naturally, a large set of tools and methods is required for addressing the many aspects of migration. Powerful tools such as radar tracking, radio tagging, studies of flight mechanics and energetic in wind tunnels, light-level geolocators, ringing data analysis, stable isotopes, and DNA sampling are widely used to discover patterns of migration (Kelly and Finch, 1998; Wink, 2006; Fiedler, 2009; Bauer et al., 2019). Using these tools, the articles in this topic cover various aspects of migration and stopover ecology, providing interesting insights about mass movements, spatial distribution, fuel deposition rate, the timing of migration, and social interactions during migration.