Landscapes of fear in anthropogenic environments: How landscapes of fear created by humans and wolves affect deer behavior and structure ecosystems

Despite significant global biodiversity losses, large carnivores and herbivores are recolonizing human-dominated environments in parts of the globe. These animals act as ecosystem engineers, profoundly influencing landscapes. However, human presence strongly affects wildlife behavior, potentially hampering their ecological roles. In human-dominated environments, prey species, such as deer and wild boar, face dual threats from humans and large carnivores, like wolves, necessitating novel behavioral adaptations that can impact ecosystems. Therefore, this research assessed how both humans and wolves affect ungulate behavior and how this impacts the ecosystem. Recreational activities were found to reduce ungulate space use in zones and near trails. This reduction led to cascading effects, including decreased browsing on vegetation, improved sapling performance, reduced tick densities, and lower carbon stocks in soil, litter, and vegetation near trails. Wolves introduced additional risk effects, with deer avoiding core wolf territories, indicating that wolves add new ecological processes even in human-dominated landscapes. These findings demonstrate that human presence significantly impacts ecosystems, altering landscape structure, disease vector dynamics, and carbon cycling—critical considerations in our rapidly changing world. Despite humans' substantial influence, the return of wolves may introduce additional effects on ungulate behavior, further shaping our ecosystems.