A study which was carried out between 2006 and 2016 examined bird death data at a 152MW windfarm on the island of Smøla off the west coast of Norway. The study found that bird deaths due to collision with turbine blades could be reduced significantly when one of the three blades on each turbine was painted black.
Birds use a narrow ‘binocular vision’ when in flight and it is taught that the rotating blades of wind turbines is seen as a motion smear, therefore not seen as a moving object. The painting of one turbine blade gives the birds a motion que which enables them to detect the turbine blades as a moving object and therefore as danger, prompting them to avoid the obstacle in due time.
In this latest study, a 72% reduction in annual fatalities was recorded when compared to control or unpainted turbines. The results were seen across a range of species, most notably the White-tailed Eagle which is red listed and recently re-introduced in Ireland.
Despite these positive results, the authors of the study have stressed that the number of deaths fluctuated considerably from year to year and the need for a more long-term study. The study also recommends a repeat of this research in other areas to ensure that the outcomes are generic and repeatable across various landscapes.
If proven over a longer period with a larger data set, this approach of contrast painting could have positive implications for the provision of renewable energy projects in areas that would otherwise have been too susceptible to bird collision risk.