Abstract
1. This report presents the comparative results of six autumn seasons of birds studies at the Saint Nikola Wind Farm (SNWF), with a focus on the impacts on migrating birds
2. Spatial and temporal dynamics in the numbers of different species passing through the wind farm territory during autumn migration 2013 (15 August to 31 October) are presented.
3. Data gathered from visual observations are analyzed.
4. The data from the autumn monitoring in the years 2008 to 2013 are used to investigate the potential change in species composition, numbers, altitude or the flight direction of birds observed in these 6 years at SNWF.
5. The variations in numbers of species, absolute number of birds, overall altitudes of flight and migratory direction of birds most sensitive to wind turbines do not indicate an adverse effect of the wind farm on diurnal migrating birds.
6. The Turbine Shutdown System probably contributed to a reduced risk of collision during all years of operation within infrequent periods of intensive soaring bird migration and provided a safety mechanism to reduce collision risk for single birds and flocks of endangered bird species.
7. The low number of victims of collision found during systematic searches for casualties under every turbine at an interval of 7 days or less in four autumn seasons does not provide evidence for additional mortality caused by SNWF that could be problematic to populations of any bird species migrating through the territory.
8. The results to date indicate that SNWF does not constitute a significant obstacle or threat, either physically or demographically to any of the populations of diurnal autumn migrants observed in this study.