In 1980s, many wetlands in China have been transformed into farmlands. In response, East Asian waterfowl populations have taken advantage of spilled seeds left after harvest and now intensively use farmlands during migration. Accordingly, waterfowl might have expanded their migration strategy from merely surfing the green wave of newly emerging vegetation to also incorporating post-harvest agricultural seeds for refueling en route. However, how migratory birds use the phenology of multiple food resources to time their seasonal migration is yet to be explored. Here, we use 166 spring migration tracks of five East Asian herbivorous waterfowl species with a mixed-effect resource selection function model to test how waterfowl use the newly emerging vegetation (the green wave) and the post-harvest agricultural seeds (the seed wave) during spring migration. We find waterfowl arrive at their core stopover sites in the Northeast China Plain after agricultural seeds become available and extend their stay after spring vegetation emerges. Smaller-bodied species tend to arrive at this area later to better use the newly emerged vegetation. Regarding the breeding site, four geese species arrive after the emergence of vegetation, while tundra swans are slightly earlier. Our findings suggest that a strategy of resource coupling has allowed waterfowl to cope with the environmental change that has occurred along their migration routes: they time their migration to exploit both natural and anthropogenic food resources. Management initiatives that combine the preservation of natural habitats with adaptive agricultural practices could safeguard these threatened, long-distance migratory bird species.