Warming of Arctic regions has generally resulted in an earlier snowmelt and a phenological advancement in the outburst of arthropods. Shorebirds that migrate to Arctic regions to breed and capitalize on this rich, but temporarily available, resource are thus expected to show a corresponding advance in their breeding phenology. However, many species show a lack of a phenological advance in laying dates, which could thus lead to a temporally mismatched reproduction with negative effects on chick growth and survival. However, long-term data on the extent and the consequences of phenological mismatches between avian predators and arthropod prey in Arctic regions are scarce. During this project, the PhD student investigates whether the growth and survival of chicks of Sanderlings (Calidris alba), an Arctic breeding shorebird, is hampered depending on the degree of phenological asynchrony with their arthropod prey. Moreover, it is investigated whether Sanderlings might be able to mitigate negative fitness consequences of a phenological mismatch by exploiting the spatiotemporal heterogeneity of arthropod abundance on the tundra and/or by altering their diet composition. The PhD student will track precocial Sanderling chicks on the Arctic tundra to assess their spatial habitat use, diet composition, growth and survival in relation to their phenological timing relative to that to that of their arthropod prey. Moreover, the collected empirical data will be integrated in a quantitative population model to predict the relative effect of chick survival on local Sanderling population dynamics.