Abstract
An exotic species can appear in a community unexpectedly. It may therefore be necessary to decide quickly whether measures are required to mitigate the impact of the newly arrived exotic species on the native community. Here, I develop a collection of theoretical models that are intended to provide insight into the effects of newly arrived exotic pollinators on pollination systems. The models address the effects of the presence of an exotic pollinator on plant reproduction, including the both the degree to which seed set is pollen-limited and the level of outcrossing, and on numerical responses by native pollinator species, including switching of flower preferences by economically motivated flower visitors. The models are simplistic, but the majority have the virtue that their solution is feasible by using data that is easy to collect. The models provide first approximations that could be useful to ecologists and conservationists when they must guess the potential impacts of exotic pollinators. The results from the models should be interpreted under appropriate caveats by those who must make do with them until better information becomes available.
