Climate change drives migratory range shift via individual plasticity in shearwaters
Résumé
Significance We repeatedly tracked Balearic shearwaters, allowing us to investigate how changes in migratory behavior generate range-shift under climate change. Range-shifts are often viewed only as population-level phenomena but we show that, in this long-lived seabird, individuals flexibly respond to increasing temperatures throughout their lives by migrating further north. We link this plasticity to changes in migratory behavior and associated spatial cognition. In particular, shearwaters appear to regulate the speed of return migration by estimating the distance of the migratory route. Nonetheless, this increased speed is insufficient to avoid delayed return phenology. These findings contribute to our understanding of how individual flexibility in migratory behaviors and spatial cognition might allow animals to track shifting resources under climate change.