Abstract
Seasonal migration is a fascinating phenomenon that enables animals to exploit seasonal peaks of resource abundance. To do so, they have to make the right decisions when to migrate and where to. Changes in any of the sites that migratory animals use during their annual cycle will affect the optimality of these decisions. Perhaps not surprisingly, in the current era of rapid and global environmental changes, migratory animals are among the most rapidly declining species in the world. To understand limits to the capacity of migratory animals to respond to changes in their annual cycle, we need to understand the mechanisms that lead to their migratory decisions. While many studies addressed the inadequate adjustments of timing of breeding in response to the advancement of spring, the ability of migratory animals to adjust migration routes in response to environmental changes at non-breeding sites and how this affects population dynamics remains largely unexplored. This project will contribute to this knowledge gap. While some aspects are shown to have a genetic basis, it is increasingly recognized that also the (social) environment plays an important role in shaping migration routes in the wild. In this study, I will perform a continental-scale common-garden experiment to investigate (1) the interplay between inherited and environmental information in shaping migration routes of the socially migrating Eurasian spoonbill, in combination with state-of-the-art tracking techniques and citizen science data to investigate (2) the importance of social and non-social environmental factors in shaping migration routes and individual-based modelling techniques to investigate (3) how social learning of migratory routes affects the adaptability of migratory animals to environmental change. With this unique combination of descriptive, experimental and theoretical work, this project will contribute to a better understanding of the ontogeny of migration, which is urgent for effective conservation of migratory species.
Netherlands