Wind energy has experienced a very rapid growth in the last few years and the majority of predictions speculate a similar scenario also for the near future. Despite the fact that wind energy is carbon free, and thus does not contribute to global warming, wind farms are not free from impacting the environment in which they are built, particularly bird and bat populations - impacts that, at least in some cases, could be remarkable and thus need to be studied and monitored. In this paper, we present the results after the first year of monitoring, aiming to understand impacts of a wind farm on birds, particularly on raptors, both residents and migrators. The study area, located in central Tuscany, hosts a very rich raptor community with some species of conservation concern. Comparing data gathered before and after the wind farm construction, we note a dramatic decrease in the number of raptor observations, even though no species have definitely left the area. Significant differences arise also considering habitat use and bird behaviour, with raptors flying higher and away from turbines, stressing an avoidance effect.