Immune defences are vital for resistance against infections, but are an overlooked component of disease dynamics in the wild. Using a uniquely powerful model system of long-term studied wild birds, this project will investigate causes of individual variation in innate immunity, the critical first-line-of-defence against new
infections. The results will show how immune dynamics are linked to disease, aging, reproduction and longevity and to what extent this is environmentally-determined or inherited (its adaptive potential). The outcomes will provide broadly generalizable insights into interactions between the immune system and the environment, and identify risk factors for vulnerability to novel infectious diseases.