Hen Harrier Circus cyaneus population trends in relation to wind farms

ABSTRACTCapsule: The data presented here demonstrate a considerable spatial overlap between wind farms and the breeding distribution of Hen Harriers in Ireland, but evidence for a negative impact of wind farms on their population is weak.Aims: To assess the extent of the overlap between wind farms and breeding Hen Harriers and to investigate their potential impact on Hen Harrier population trends.Methods: Data on Hen Harrier breeding distribution in 10 km × 10 km survey squares from national surveys were used in conjunction with information on the location of wind farms to examine whether, and to what extent, changes in Hen Harrier distribution and abundance between 2000 and 2010 were related to wind energy development.Results: Of the 69 survey squares holding Hen Harriers during the 2010 breeding season, 28% also overlapped with one or more wind farms. Data from 36 of the squares with breeding Hen Harriers during the 2000 survey revealed a marginally non-significant negative relationship between wind far...