An important area of interest in behavioural ecology is to understand the large variation in traits related to reproduction and one explanation is that this variation is adaptive and is shaped by natural selection. In wild populations, multiple selection pressures are likely to simultaneously shape trait evolution. While these multiple selection pressures can manifest through different ecological or demographic conditions, these conditions themselves could vary predictably over space or time, or in an unpredictable manner, a relatively less studied form of environmental variability.

In my thesis, I attempt to understand how oviposition site selection, a behaviour where multiple selection pressure regimes are rarely considered, is shaped by multiple factors in a variable environment. Using *Aedes aegypti* as a model system, I first measured fitness trade-offs associated with larval predation risk and conspecific competition risk at potential oviposition sites through experimental manipulation in the laboratory. I also quantified spatial and temporal variation in two risk factors, pool desiccation risk and larval predation risk, through an observational study under natural conditions. Considering these trade-offs, I predicted and tested female oviposition site selection response to these varying multiple risk factors in the field. My findings indicate that oviposition site selection responses are complex, sensitive to interactions between multiple risk factors and influenced by patterns in variability in some of these factors.