Data from: 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.