Abstract
Environments differ and constantly change, due to natural processes and human impact. How animals adjust their immune system - central to protection against pathogens and diseases - to environmental change is not well understood. Because immune function is costly, animals should match their immune system to the threats they face. However, it is unknown what these threats are, how pathogen diversity and abundance differ among environments and seasons, and which pathogens are most important. Yet, this knowledge is crucial to place immune defenses in an ecological and evolutionary context. It is also imperative for biodiversity conservation and vital for human and animal health care. Over the past decade Immuno-Ecology has advanced rapidly, thanks to development and application of field-friendly and ecologically relevant immunological indices. The next breakthrough will come from transforming pathogens from highly threatening but anonymous players to central characters in the foreground of research. Applying state-of-the-art techniques from Microbial Ecology can achieve this. I exploit an elegantly simple and widespread avian model, the 'egg-nest' dyad, to fully elucidate the association between antimicrobial defenses of eggs and microbial communities in their environment. Specifically, I investigate evolved responses in a comparative field study of closely-related larks spanning a wide variety of environments, individual responses in a novel tropical system with large climatic variation at small spatial and temporal scales, and phenotypic flexibility of antimicrobial defenses of captive birds in response to experimental manipulations of microbial communities. My team's complementary work in these systems allows integration of results with physiology, behavior and life-history, including adult immune function. This first attempt to map microbial and pathogen landscapes and concurrent avian responses, opens up important new avenues to understand selection pressures on vertebrate immune function, individual traits related to disease resistance, and their relationships with distributions and numbers of animals in a changing world.
Netherlands