Abstract
The project objective is to investigate how large predators impact the composition of mammal communities. Large predators have been heavily persecuted and many populations have declined or gone extinct. Some declines were followed by increased abundances of medium-sized (meso) predators, which in turn may affect the abundance and diversity of prey. The mesopredator release hypothesis suggests that reduced levels of competition and predation from larger predators caused the increased mesopredator densities. Thus, large predators may have substantial effects on the structure of ecological communities. However, the hypothesis has not been experimentally or theoretically tested and alternative explanations for the observed patterns are possible. Spatially explicit and individually based modelling offers a route to analyse the impact of both predation and competition on community dynamics. This is a new approach within theoretical ecology, which I will use to test the hypothesis that reductions in wolf (Canis lupus) and lynx (Lynx lynx) populations caused a mesopredator release of red foxes (Vulpes vulpes) in Sweden. Specifically, I will test if known species interactions are a sufficient explanation for observed changes in species abundances and community structure. The results are generally important for scientific theories on mesopredator release and the use of spatially explicit population models. Further, they may have implications for wildlife management.
Sweden