Upland raptors and the assessment of wind farm impacts

Abstract

Government targets on renewable energy coupled with anthropogenic constraints on development have resulted in a surge in proposals to locate wind farms in upland areas, where they may conflict with the wellbeing of scarce or rare bird species including raptors. European and UK legislation demand that the effects of wind farm developments, both individually and in combination, be assessed to determine the level of impact on these species. The principle adverse effects of wind farms on raptors, as for other terrestrial birds, potentially involve disturbance (displacement or barrier impacts) or collision fatality. Few long-term studies on such effects of wind farms have been undertaken. We review available research results on displacement of raptors, which primarily involve foraging birds, and conclude that most studies indicate that displacement appears to be negligible, although some notable exceptions occur and more research is needed. There is also a need for better understanding of the numbers of birds likely to be killed through collision with turbine rotors at the site level in order to inform planning decisions, although models of bird distribution at several spatial scales can be used to circumvent potential difficulties when locating turbines. Modelling approaches have also been developed that attempt to quantify the theoretical risk of collision. One such approach, the Band model, is a valuable tool for impact assessment and its use is now widespread in the UK. However, there are practical problems associated with gathering the data required to run the model and numerous assumptions must be made concerning bird behaviour. This can lead to deficiencies in the input parameters which potentially have a large effect on the model outputs. Hence, we make recommendations for potential improvements, such as quantifying error in flight height estimation, training of observers in acuity skills, quantifying bird detection-distance functions, and research on factors influencing activity budgets and flight behaviour. In addition, the model outputs are usually adjusted to take account of turbine avoidance by birds and this aspect of birds' behaviour is poorly understood. As a result of these limitations, collision predictions are only indicative, and more reliable in some situations, and for some species, than others.

Census of migrating raptors at Breginjski Stol (NW Slovenia) - the first confirmed bottleneck site in Slovenia

“…Based on our experience and local topography, an observer using a spotting scope can cover distances of ca. 4 km from the main observation point Mali vrh, although for accurate determination most bird species have to be closer (Madders & Whitfield 2006). All raptors that crossed Breginjski Stol perpendicular to the ridge on locations farther from the observation point than 4 km were overlooked.…”

Future of biodiversity in the Barents Region

“…The best location for wind farms is dependent on many factors, such as wind supply, aviation, landscape visual concern, and ecology (Madders and Whitfield 2006). Wind farms tend to be situated at locations with strong winds and away from human population (Madders and Whitfield 2006). However golden eagles favour the same places (Moss 2011), which leads to some conservation issues (Madders and Whitfield 2006), especially since the golden eagle is classified as near threatened in Sweden (http://www.artfakta.se).…”

“…Wind farms tend to be situated at locations with strong winds and away from human population (Madders and Whitfield 2006). However golden eagles favour the same places (Moss 2011), which leads to some conservation issues (Madders and Whitfield 2006), especially since the golden eagle is classified as near threatened in Sweden (http://www.artfakta.se). In order to conserve the species, areas that need extra protection must be identified (Araújo et al 2011).…”

“…The potential range expansion of golden eagles calls for protection of potential nesting trees in areas where it is absent today. The best location for wind farms is dependent on many factors, such as wind supply, aviation, landscape visual concern, and ecology (Madders and Whitfield 2006). Wind farms tend to be situated at locations with strong winds and away from human population (Madders and Whitfield 2006).…”

A Net-Present Value Analysis for a Wind Turbine Purchase at a Small US College

“…One of the reasons for such a wide range is that there is not standardized survey methodology for measuring the mortality rate. For instance, scavengers may remove carcasses [33,34]. Mortality rates vary by both species and by season as well as by location [35].…”