Having an efficient immune system is highly beneficial in a world teeming with parasites. The maintenance of such a system is, however, costly because it requires resources that could be used for other purposes. Investing resources in reproduction or molt could lower the optimal level of immune defence. On the other hand, a high level of defence might be a prerequisite for successful breeding and molting. So it is not obvious how the optimal level of immunity should vary over the year. Here we use an optimal annual routine model of the behavior of non-migratory birds to investigate the optimal level of immune defence over the annual cycle. In our model, decisions depend on the time of year and a set of state variables that include energy reserves, breeding status, experience, quality of the primary flight feathers and condition of the immune system; explicit density dependence in the food supply is also incorporated. We use the model to investigate how the optimal level of immune defence should change over the year, and how seasonality in the chance of parasite infection influences the optimal level and annual behavior.
Bibliographical notePublisher: Springer
Name and Venue of Conference: XXIV International Ornithological Congress, Hamburg
Medium/genre: Meeting abstract
Other identifier: IDS number 081JF