Consequences of animal migration in an era of global change

Abstract

Due to the importance of migration as an adaptation to environmental variation for many animals, it is clear that migration mediates the consequences of environmental change for migratory populations. Migration also clearly mediates the consequences of environmental change for broader ecosystems whenever changes to migratory strategies and migratory population sizes affect the ecological role of migrants. However, because both migration and environmental change are complex phenomena, it is less clear how migration mediate the consequences of environmental change. In this thesis I develop ecological theory to elucidate ways in which migration might mediate the consequences of climate change for migratory populations (Theme 1, Chapters 1 and 2) and the consequences of environmental change for disease dynamics (Theme 2, Chapter 3). In Chapter 1, I build a model to understand the role of migratory cues in determining the severity of phenological mismatch experienced by migrants following phenological change. In Chapter 2, I explore how spatial aggregation of populations mediates the effect of spatially restricted disturbances, like extreme climate events. In Chapter 3, I determine how two traits associated with migration, tolerance to infection and pace of life, affect pathogen trait evolution and the impact of disease on populations following spillover events. Together, these projects advance our understanding of how migration mediates the consequences of environmental change. This in turn improves our ability to make predictions and design effective conservation strategies in our current era of rapid environmental change.