Immune function as physiological mechanism of carry-over effects, current vs. future reproduction and predation

In an animal’s life, different stages of a year are tightly connected. Events during one stage can influence the performance of individuals in subsequent stages. So-called ‘carry-over effects’ can strongly impact reproduction and survival, two central parameters in ecology, evolution and conservation. The physiological mechanisms underlying carry-over effects are poorly understood. Immune function, i.e. resistance to diseases or infections, is hypothesised as one important mediator. We are using current advances in the ability to measure physiological parameters of wild birds and cutting-edge tracking-technology to quantify the role of immune function as a physiological mechanism of carry-over effects. By combining experimental and correlative approaches in different study set-ups will we generate a new understanding of how immune function mediates carry-over effects.
Aspects of this research field can be found in most of my projects. Two examples where we focus on vary-over effects include:
1) The trade-off between current and future reproduction. What determines investment in self-maintenance and reproduction? The immune system is a main physiological system promoting survival and hence the possibility for future reproduction.
2) Predation. Next to diseases, predation is probably the most important cause for mortality in most species. Predators are expected to prefer prey that is easiest to catch. This could be for example small individuals or sick individuals expressing sickness-induced lethargy. Hence, predation might only be a consequence of disease-related sickness or insufficient investment into immune function.