Migratory herbivorous waterfowl track multiple resource waves during spring migration

East Asian herbivorous waterfowl intensively use farmland in spring, next to their natural habitat. Accordingly, they might have expanded their migration strategy from merely tracking the green wave of newly emerging vegetation to also incorporating the availability of post-harvest agricultural seeds (here dubbed the seed wave). However, if and how waterfowl use multiple food resources to time their seasonal migration is still unknown. We test this migration strategy using 167 spring migration tracks of five East Asian herbivorous waterfowl species and mixed-effect resource selection function models. We find all study species arrive at their core stopover sites in the Northeast China Plain after agricultural seeds become available, extend their stay after spring vegetation emerges, and arrive at breeding sites around the emergence of vegetation. At the core stopover sites, all study species use snowmelt as a cue to track seed availability, although smaller-bodied species tend to arrive later. At the breeding sites, swans track the onset of vegetation emergence and geese track the mid or end phrases of snowmelt. Our findings suggest that waterfowl track multiple resource waves to finetune their migration, highlighting new opportunities for conservation.