Modelling risks posed by wind turbines and power lines to soaring birds: the black stork (Ciconia nigra) in Italy as a case study

Recent growth of investments in wind energy and power industries has increased concerns about the associated adverse impacts on wildlife. In particular, flying vertebrates are especially at risk, both directly, through an extra mortality rate due to collision with turbines and electrocution, and indirectly through habitat loss or fragmentation. In this study, we propose a modelling approach that combines species distribution models and data managed in geographic information systems to predict and quantify the effects of wind turbines and power lines on the breeding habitat of a soaring migratory bird, the black stork Ciconia nigra, in Italy. The species is recolonizing the country, where it had been driven to extinction in the Middle Age by human persecution. Today, infrastructures such as those considered in our study might in fact hamper this recolonization. Our results show a high probability of presence of the species in several areas in Italy. The most important variables in influencing habitat suitability for C. nigra are the mean temperature of May followed by the distance from urban areas, inland wetlands and hydrographic network. Exposure to wind turbine collision and electrocution resulted to be potentially high. In particular, in Northern Italy the main potential risk of mortality for C. nigra is posed by power lines, whereas in southern regions the species might be mostly threatened by wind turbines. Our approach makes it possible to detect suitable areas that, although not yet colonized by the species, would imply a high mortality risk should the species colonize them in the future. The tool we provide may therefore prove useful to conservationists and landscape planners in order to mitigate the impact of human infrastructures on this species and encourage a more sustainable planning.