One of the major considerations any wind farm application must overcome is the Environmental Impact Assessment (EIA). The effect the development might have on local and migratory birds is a key part of this process, and similar concerns can also hamper the expansion of an established wind farm, as happened recently with the London Array. (The second phase of the project has been scrapped due to uncertainty about its impact on the local red-throated diver population, a decision which will greatly reduce the array’s proposed capacity.)
However, a recent radar study of a group of wind farms off the coast of Lincolnshire in eastern England found little evidence that the turbines have harmed the tens of thousands of pink-footed geese that migrate past them each year, giving hope to developers that this stage of the wind farm consenting process could become easier to navigate in future.
“The study has implications for geese species in general and the way that they avoid wind farms”, says Ian Simms of engineering services company AMEC, which carried out the latest year of study for Centrica Energy in autumn 2013. “But it also has implications for bird monitoring and the effects of wind farms in general.”
The pre-construction EIA for the Lincolnshire wind farms listed 78 bird species in the area, of which the migratory pink-footed goose is the one of the most sensitive: it is protected under UK and EU law. Almost 90% of the world’s population overwinter in the UK from breeding grounds in Iceland and Greenland. In 2007, a year before the first two of the three wind farms came into operation, researchers began to study their migratory patterns.
Radar tracks from the first four years of the study show the main migration route for the geese has moved to one side of the turbines. The birds then continue south to their overwintering site in Norfolk.
“They tend to fly either around the wind farms or over the top”, says Simms, who believes that the study is unlikely to alter the siting of wind farms, but feels “it might make the consenting process easier”.
The study is now in what is likely to be its final year, making it the longest project of its kind, generating an unprecedented amount of detail about the behaviour of birds around wind farms. Past studies of migrating birds have relied on a combination of military data, which is less sensitive, or weather radar, which can only pick up general information on flock height and direction, backed up by visual identification during daylight hours – but migration often takes place at night.
Eagles have been hit by wind turbines in the US and Norway, generating considerable publicity in the process. However, Simms says: “Our empirical evidence shows that while that might happen, we have 80,000 birds that are migrating each year and avoiding the turbines. This study is putting a knowledge base out there that birds do avoid wind farms without changing their migratory route.”
UK bird charity and lobbying group the Royal Society for the Protection of Birds (RSPB), which initially opposed most onshore wind farm planning applications, has become more selective in recent years, focusing on the need to identify appropriate sites for turbine arrays, so that they don’t damage wildlife.
“We don’t know enough yet about bird behaviour and wind farms”, says Nik Shelton, a spokesperson for the RSPB. “But we are gathering evidence, and studies like this one sound like exactly the sort of thing we need.” For Simms, another potential upshot from the study could be the ability to monitor the longer-term effects of climate change on migratory patterns in all weathers and at all times of day.
“The use of radar to add to empirical evidence of sightings can be a useful additional tool to help develop an understanding of how bird migration timings, patterns and even routes are being affected by climate change”, he says. “If the radar study was carried out for another 20 years, we would be able to see the detailed changes that are going on.” – Jeremy Lovell
AMEC is a Forum for the Future partner. www.amec.com
Photo credit: Richard Taylor Jones