The Indirect Impacts of Wind Farms on Terrestrial Mammals: Insights from the Disturbance and Exclusion Effects on Wolves ( Canis lupus )

Due to the technical and functional characteristics of wind turbines, impact assessment studies have focused mainly on flying vertebrates. Nevertheless, evidence from the little available knowledge indicates potential impacts on large terrestrial mammals resulting from habitat fragmentation and increasing human disturbance. Over the last 15 years, more than 900 wind turbines were built inside the range of the Portuguese wolf. Due to the endangered status of this large carnivore in Portugal, several monitoring plans were conducted, resulting in a reasonable amount of information being collected on the effects of wind farms on wolves. We reviewed the methodological approaches, compiled major findings and summarised the mitigation/compensation measures used in Portuguese wind farms. The overall outcomes show increasing human disturbance in wind farm areas, resulting in lower wolf reproduction rates during construction and the first years of operation, as well as shifts in denning site locations of more than 2.5 km away from the wind farm. These findings are of major concern in humanised landscapes, where suitable wolf breeding habitats are reduced. As precautionary measure, new wind farm projects should be restricted in areas that are closer than 2 km from known wolf denning locations.