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 ..., , , # Migratory herbivorous waterfowl track multiple resource waves during spring migration

This work analyzes satellite tracking data of five migratory herbivorous waterfowl species in East Asia to investigate if and how herbivorous waterfowl track multiple resource waves during spring migration.

### Description of data and file structure:

**R Scripts:**

* **01 - Analyzing migration parameters.R:** R script that reads in the output of identified sites (calculated in SaTScan) and calculates migration parameters.
* **02 - Investigating resource utilization in migration.R:** R script that analyses habitat use intensity on farmlands and natural habitats across time, and investigates habitat switch before and after the emergence of vegetation at core stopover sites in the Northeast China Plain.
* **R scripts 03-06:** **Determine the bird arrival and resource availability relationship.**
03 - Testing differences in resource and migration timing.R: R script that shows resource and migration...