Sex, parasites and coevolution : improving forecasts for the distribution of the New Zealand mudsnail Potamopyrgus antipodarum.

For the fields of invasion biology and conservation science, the ability to predict the distribution of a species is crucial. Even more so, the ability to identify where a species distribution will expand to before it actually occurs can be imperative to mapping and controlling growing distributions. For these issues, Species Distribution Models (SDMs) are used to predict the distribution of the target species by relating the species presence or abundance to a variety of environmental or spatial characteristics. It has been suggested that SDMs are limited in their ability to predict species distributions because ecological theory is not fully integrated in the modelling process. This idea is realised through the lack of inclusion of biotic interactions into SDMs, as SDMs currently are unable to predict the changing range limits of a species that occur due to constantly changing biotic interactions such as competition, predation and dispersal limitation. This thesis was able to show through simulating population growth under different abiotic and biotic conditions that the coevolutionary interaction between Potamopyrgus antipodarum and its trematode parasites is important to include in SDMs if they are to accurately predict the distribution of P. antipodarum. The research presented in this thesis connects the already well-established field of ecological niche modelling with the complexity of modelling biotic interactions, opening the door for exciting advances in the field of distribution modelling and predicting invasive species ranges