Navigating time and space: The evolutionary movement ecology of a polygamous partial migrant

• Applicant: Dr. Luke Eberhart-Hertel, Ph.D.
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Evolution, Anthropology
• Term: from 2018 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 415037502

Why do animals leave their familiar settings and venture into the unknown? In animal ecology, dispersal describes the movement of individuals from one breeding site to another with the intent to maximise fecundity, whereas migration encapsulates individual movements between breeding and non-breeding sites with the intent to maximise survival until the next reproductive period. Despite the risks associated with moving into a novel environment, dispersal and migration remain fundamental components of animal life-history. The exchange of individuals across time and space has important knock-on effects on ecosystem processes, such as predator-prey, plant-pollinator, and host-parasite dynamics. Although much research has focused on documenting the physiological adaptations associated with migration and the population genetic consequences of dispersal, our knowledge about the evolutionary ecology of animal movement still has prominent gaps. Here, I propose to investigate the social and ecological drivers of individual- and population-level heterogeneity in dispersal and migration of a polygamous and partially migratory shorebird breeding across a 4,500 km latitudinal gradient. Taken together, studying individual heterogeneity in dispersal and migration behaviour concurrently allows for a comprehensive assessment of the selective factors shaping the evolutionary ecology of animal movement across time and space that may help to explain variation in fecundity and survival: the two fitness components at the crux of life-history evolution. Although the evolutionary mechanisms explaining dispersal and migration strategies are well established in theory, empirical evidence remains scarce due to the difficulty of following individual movements across vast landscapes over the full annual cycle. Fortunately, recent advances in satellite-based tracking now offer biologists the enticing opportunity to explore previously uncharted aspects of animal movement ecology.My proposed project will fully integrate concepts developed in behavioural ecology, population biology, and movement ecology by studying breeding dispersal and migration in the context of individual-level variation and population-level dynamics, thus addressing the unresolved questions of i) whether breeding behaviour during courtship, mating, and parental care regulate the movement schedules of males and females, ii) whether movement propensity is driven by local social or ecological factors, and iii) whether movements are related to reproductive success or survival. To accomplish these objectives, I propose to combine state-of-the-art animal tracking technology with detailed long-term demographic data to understand the feedbacks between individual-level variation in movement and spatially-structured population-level dynamics in a model shorebird species, the snowy plover (Charadrius nivosus) – a polygamous, partial migrant spanning the west coast of North America.

• DFG Programme: Research Grants