Bird Migration Monitoring in the Saint Nikola Wind Farm Territory, Kaliakra Region in Autumn 2014, an Analysis of Potential Impact after Five Years of Operation

Report

Title: Bird Migration Monitoring in the Saint Nikola Wind Farm Territory, Kaliakra Region in Autumn 2014, an Analysis of Potential Impact after Five Years of Operation

Author:

Zehtindjiev, P.; Whitfield, D.

Publication Date:

January 1, 2014

Pages:

Affiliation

AES Geo Energy

Technology:

Wind Energy, Land-Based Wind

Receptor:

Birds

Document Access

Website:

External Link

Attachment:

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Citation

Zehtindjiev, P.; Whitfield, D. (2014). Bird Migration Monitoring in the Saint Nikola Wind Farm Territory, Kaliakra Region in Autumn 2014, an Analysis of Potential Impact after Five Years of Operation. Report by AES Geo Energy.

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Abstract

This report presents the results of 90 consecutive days of monitoring and mitigation at Saint Nikola Wind Farm (SNWF) in 2014, its 5th operational year. The Continued purpose is to investigate the possible impacts on migrating birds.
Spatial and temporal dynamics in the numbers of different species passing through the wind farm territory during autumn migration 2014 (15 August to 31 October) are presented. The data from the autumn monitoring in the years 2008 to 2014 are used to investigate the potential change in species composition, numbers altitudes or the flight direction of birds observed in these seven years at SNWF.
The variations in number 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.
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.
Results of trials in autumn 2014 for the efficiency of observers searching for collision victims and for carcass persistence rates were broadly similar to those in previous autumns (2009 and 2010) and continued to support the assumption that with a seven day inter-search interval under turbines approximately 50% of collision victims of target species should be found.
11 victims of collision were found including two bird species of conservation significance, during 777 searches under all 52 turbines for casualties at an interval 7 days or less. Additionally one old skeleton of a pelican as well as an injured white stork rescued by the field ornithologists are reported, but cannot be associated with collision from turbine blades.
The predicted mortality rates by species based on preconstruction data on numbers of migrating birds are not supported by the mortality observed during any of the 5 years of operation of SNWF. The levels of mortality predicted pre-construction have not been recorded during operation. This is largely because worst case predictions were based on BSPB data that substantially exaggerate the numbers of migrants passing through SNWF. The results to date indicate that mortality at 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.