Integrated spatially-explicit models predict pervasive risks to recolonizing wolves in Scandinavia from human-driven mortality

Abstract

Human-driven wildlife mortality is caused by both indirect causes and direct persecution due to conflicts of interests. The wolf, a predator frequently at risk from human-wildlife conflict, is returning to areas where it was historically extirpated in Scandinavia (Sweden and Norway). The wolf is expanding via a management strategy that allows wolves to reproduce exclusively in a wolf breeding range (WBR) in the south-central region. We modelled wolf territory occurrence in the WBR and all of Scandinavia, accounting for biotic and anthropogenic variables, and we also modelled the occurrence of human-driven mortality (traffic collisions, culling and illegal killing). We integrated territory distribution and mortality models in a two-dimensional model estimating habitat suitability and mortality risk for wolves. Forest was the main variable driving territory occurrence, and mortality was a consequence of variables associated with traffic infrastructure, human population, prey densities, and wolf management levels. Only <0.1% of the WBR was not characterized by these risks. Our results confirm that human-related conflicts resulting in wolf mortality occur wherever the species is present, which leads to actions to control the population expansion. Considering the adaptability of wolves and the presence of potential suitable habitat in Scandinavia, their survival and expansion will be dependent on changes in public attitudes about illegal killing, and a review of policies and management actions. Our framework can be used to assist management of human-wildlife conflicts of recolonizing wolves elsewhere, or of other species at high risk from human-induced mortality.