Turbine searches were carried out between February 2007 and March 2012. Thus, without avoidance, the model predicted there would be 165.68 collisions per year. During this period a total of 11.6 hours of red kite activity was observed (c.5 % of total observation time) within 500 m of the proposed turbine envelope.īased on a layout of 36 turbines, which operate 87 % of the time, the Band CRM, populated by the empirical flight data, predicted there was 1518 red kite transits through the rotor swept area per year. The initial collision risk modelling was based on flight activity data gathered by Natural Research (Projects) Ltd during vantage point observations totalling 199.1 hours between September 2004 and May 2006, i.e. This is the only known study of avoidance rate, incorporating both pre- and post- construction data, to have been completed in the UK, and possibly in Europe. Coupled with this analysis, correction factors for searcher detection error, carcass persistence and the proportion of carcasses that may have fallen outside the turbine search area were derived, allowing adjusted estimates of collision mortality to be made. Our approach therefore also followed the SNH recommended procedure by which avoidance rates should preferentially be derived.Īnalysis of pre-construction flight activity of red kite and post-construction turbine searches was undertaken at the Braes of Doune wind farm in central Scotland. Our approach mimicked the most common usage of the Band CRM: the model is primarily, and in origin, a predictive tool (applied pre-construction and in assessment of proposed wind farms). The objective of the present NRIN 7 was to evaluate the most suitable value for an avoidance rate for red kites under the Band CRM, using empirical data derived before and after the construction of a wind farm. There has been much recent interest in the possible consequences of collision mortality at wind farms for this European endemic species. This recommendation is based on a simplistic comparator argument presented by a previous NRIN 3 (Whitfield & Madders 2006). Stage 3 is a heavily influential aspect of the CRM process despite it not being formally part of the CRM process, and is termed the “avoidance rate”.Ĭurrently, according to Scottish Natural Heritage (SNH 2016) guidance the recommended avoidance rate for red kite Milvus milvus under the Band CRM is 98 %. The Band CRM is essentially a ‘no avoidance’ model, and to bring predictions towards a semblance of reality a correction factor must be applied as a final element in the calculations (‘Stage 3’).

(2007) attempts to estimate the number of fatalities at an operational wind farm that will result from birds colliding with rotating turbine blades due to given levels of flight activity (Stage 1) and the probability of a bird passing through spinning rotor blades actually being hit by the blades (Stage 2). The Band Collision Risk Model (CRM) described by Band et al.

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