Factors promoting bird mortality at wind turbine structures

Biodiversity related impacts at wind energy facilities have increasingly become a cause for serious conservation concern, the central issue being the slaughter of a large number of birds. We aim to identify the major factors that conver high fatality risks to birds at wind farms. For this purpose, we combine species distribution modeling with assessments of bird mortality data estimated by carcass searches around wind turbines and their linkage to the ecological conditions at the respective wind turbines located in the federal state of Brandenburg, Germany. We quantify mortality in relation to a sets of independent ecogeographical variables; climatic, topographic and habitat based variables, taking into account the environmental characteristics that might influence avian mortality at the wind turbine structures. For these analyses, we group the available bird carcass data exclusively for the "Birds of Prey: Raptors" owing to their higher number of fatalities, recorded from 2000 to 2011. Secondly, we develop predictive models to determine hotspot areas with higher risk of avian fatalities and assess the optimal set of ecological factors promoting it. The approach, not only provides valuable insights by ranking and also ultimately subsetting an optimal set of explanatories that best explain the variations of the mortality data, but also highlights important interactions among these explanatories, delineating the root cause of the conflict. Besides that, the subsequent results could even be used to direct future energy development with minimal biodiversity risks, by directing wind turbine installations based on both; energy potential benefits and such associated risk based assessments, thereby minimizing the conflict between renewable energy and biodiversity protection.