All you can eat: Artificial feeding sites affect large herbivores and their predator in a human-dominated landscape

Abstract

The re-expansion of large mammals in European human-dominated landscapes poses new challenges for wildlife conservation and management practices. Supplementary feeding of ungulates is a widespread practice with several motivations, including hunting, yet the known effects on target and non-target species have yet to be disentangled. According to optimal foraging theory, such concentrated food sources may attract herbivores and carnivores in turn. As such, feeding sites may skew the spatial distribution of wildlife and alter intra-and interspecific interactions, including predator–prey dynamics. Here, we investigated the use of ungulate-specific feeding sites by target and non-target species in a human-dominated and touristic area of the Alps, using systematic camera trapping. We assessed potential temporal segregation between roe deer and red deer at feeding sites and whether these concentrated artificial food sources influenced the occurrence and site use intensity of ungulates and wolves at the broader scale. We found that feeding site frequentation by roe deer was influenced by the presence of red deer, with a higher crepuscular and diurnal activity and a longer time span between visits at feeding stations strongly used by red deer, indicating potential temporal niche partitioning between the two ungulates. We also found that ungulates occurred with a higher probability at shorter distances from feeding sites and used sites with high human outdoor activity less intensively than less disturbed ones. Wolves' site use intensity was higher closer to feeding sites, indicating a potential effect of supplemental feeding sites on both prey's and predators' space use. Our results reveal side effects of artificial feeding sites, thus contributing to a more informed and evidence-based management, with high relevance especially in light of the considerable recovery of large mammals across anthropized regions of Europe and the popularity of artificial feeding of ungulates for hunting or recreational purposes. We thus advise limiting this practice in areas where large herbivores, predators, and humans closely coexist.