AI Representation: An owl decoy and a sound-emitting speaker near wind turbines. Image credits: Chatgpt
A 2019 pilot study by Dorey, Dickey and Walker tested whether an artificial owl and recorded predator and alarm calls could deter birds from the area around turbines at a wind farm in Nova Scotia, Canada. Its fieldwork took place in August and September 2016, and the authors reported no statistically significant deterrent effect on birds at the site compared with control sites. Walker published Testing Efficacy of Bird Deterrents at Wind Turbine Facilities: A Pilot Study in Nova Scotia, Canada, in the Proceedings of the Nova Scotian Institute of Science in 2019. The visual deterrent was a Bird-X Prowler Owl, an owl model with moving wings, perched within 50 metres of a turbine. The pilot study took place from 22 August to 16 September 2016 at a 5-turbine wind farm about 20 km northwest of Halifax. Across 12 sampling events, the authors note, low bird abundance and limited statistical power constrained the pilot.
This comparison was essential since birds could vary their usage of the habitat due to factors not associated with the deterrents at all. There was no statistically significant decrease in the activity of the birds due to the use of the deterrents when compared to the control. Because a deterrent can change where birds fly or how they behave near a turbine without reducing collisions or deaths, for wind farm operators the difference matters,. Because there is a feasible mechanism there is necessarily a benefit, wildlife protection requires stronger evidence The Nova Scotia studies are part of the larger problem in wind energy development of finding solutions to minimize any impact on wildlife while not assuming that. Because what works for one species at one location may not work for another, the studies should consider the differences in species and locations,.
Katherine Dorey, Scott Dickey and Tony R. The researchers tested two kinds of deterrents. The audio deterrent was playback of a Red-tailed Hawk call mixed with alarm calls from Ovenbirds and White-throated Sparrows, used to find out whether warning signals affect bird activity. The bird activity in the presence of the deterrents was compared with that in the absence of the deterrents. The authors compared four trial types: an owl model, the owl model plus predator and alarm call playback, a rotating control turbine, and a stationary control turbine. Thus, the research did not confirm that the owl models or recordings prevented the birds from approaching the areas where the turbines were located. Such a conclusion should be taken into account properly. The lack of statistical significance does not mean that the deterrent cannot work. However, the experiment did not show that the deterrents were effective. The result also cannot show whether differently designed decoys, other sound recordings, or other combinations of the two would perform differently. Moreover, it is worth mentioning that the experiment did not confirm that the methods reduce the number of collisions and thus mortality of birds. Such changes are two different outcomes, and evidence of one of them cannot confirm the other. The Canadian Impact Assessment Agency’s review , Strategies for Mitigating Impacts to Aerofauna from Offshore Wind Energy Development: Available Evidence and Data Gaps , examines a range of mitigation strategies for offshore wind development and identifies gaps in the available evidence. Further studies could investigate the effect that different decoys, sounds, playback times, and methods have on the birds.
