Abstract
Wind power generation plants are a worldwide concern because of their potential negative effects on bird populations. To reduce this impact, theoretical models that evaluate the risk of birds colliding with wind turbines have been implemented for wind farms as part of environmental impact assessments. However, collision risk evaluation models have various difficulties when predicting collision events for each wind turbine within a given wind farm due to different topological features and local weather conditions. Current collision risk models require species-specific avoidance rates to estimate collision risk, but there are no data on the avoidance rates of bird species in Japan. Moreover, few impact assessment practices have considered either the long-term impact of each wind power plant on bird population viability or the cumulative impact of multiple wind farms on bird populations, although both considerations are critical requirements for the conservation of endangered species in areas where many wind farms have been built. This paper reviews the data on the collision and avoidance rates of many bird species over various geographic ranges and the long-term and cumulative impacts on bird population viability, with the aim of implementing contrivance measures for the bird collision risks at operating and planned wind farms.
