ProjectLink between immune response and environment in tree swallows (Tachycineta bicolor)
Recent studies have shown that the environment affects the immune response differently between distinct populations of the same species but also within the same population. This new approach called ecoimmunology is useful to investigate the trade-offs between defenses strategies and different fitness components of the host. These trade-offs are important as they play a key role in the evolution of resistance mechanisms of organisms against their parasites. My project aims to investigate these trade-offs by studying the effects of the variations in time and space of parasite distribution on their host immune system as well as the effects of environmental variations within the same population. My study system will be the tree swallow, a group of insectivorous birds which the population is recently declining partly due to agricultural intensification. I will use a data base composed of 100 nests followed since 2007 and I will follow up data collection for 3 years between 2013 and 2015. These nests are located in two different areas: intensive agricultural zones and extensive ones both constitute two distinct environments that have been shown to have an impact on the immune response in this tree swallow species. I will add new variables such as pathogen infection indices and ectoparasite indices.