Predator-prey interactions through the lens of coevolution and ecological context

University of Technology Sydney. Faculty of Science.The red fox (Vulpes vulpes) is one of the world’s most widely distributed mesopredators. They influence ecosystems primarily through the predation of prey species, driving cascading effects on plant and animal communities. In modern times, red foxes have been introduced to new locales, forming part of native and non-native conglomerates. The resulting amalgamation of native and non-native predator communities have been described as producing novel trophic cascades. While some acknowledge the important rewiring of lost functions due to extinction, there remains widespread concern about the negative role introduced species might play as they lack coevolved traits and relationships with native prey. To that end, the introduction of novel predators, like foxes, has been suggested to be a leading cause of decline and extinction of small mammal prey, especially in Australia. Rather than detailed consideration of the niche that introduced predators fit into, and their functional similarities with lost species, foxes and other introduced mesopredators like cats (Felis catus) are maligned by conservation values that promote native prey and the prevention of extinction. Negative connotations around alien and invasive species frequently override sound ecological assessment and cloud the establishment of evidence-based environmental policy. Rather than absorbing narratives of harm, what happens when we suspend our assumptions that introduced species are ecologically damaging? Is it possible that the role of introduced mesopredators in driving extinctions is overstated? Is it also possible that long histories of coevolution are less important than the contextual and functional roles predators play in trophic cascades? Asking these questions is vital if we are to find transparent and peaceful ecological solutions to improve nature conservation and prevent extinction and harm. Within this thesis, I explore these questions with a desire to understand how the red fox shapes the behaviour and ecology of their prey and how this compares to the foxes native range. Further, I explore how the fox fits into Australian novel ecosystems but exploring their interactions with dingoes and how these are shaped by human hunting. Red foxes, like any other predator, play important ecological roles, however, assumptions of their harm, have prevented us from fully exploring their ecologies within novel ecosystems. By dropping assumptions that foxes are inherently harmful, I show that the foxes biotic nativeness has very little to do with their ecological interactions, the foxes ecology and behaviour may, instead be better predicted by ecological context