Upland birds face displacement threat from poorly sited wind turbines
26 September 2009
A new study across 12 operating upland wind farms in the UK suggests that numbers of several breeding birds of high conservation concern are reduced close to wind turbines. If wind farms are sited inappropriately in areas where these vulnerable birds breed at high densities, then those populations may subsequently decline.
The new study should help developers planning renewable energy projects by offering greater certainty as to likely impacts so that they can quickly progress acceptable proposals in appropriate locations by avoiding important areas for birds.
Wind farms are regarded as having two major impacts on bird populations. The first, collision, has received most attention, and has been shown to result in bird strike mortality, notably of raptors, at some sites. The second, disturbance displacement, describes the fact that birds may use areas close to the turbines less often than would be expected, potentially reducing the carrying capacity of an area. It is this second mechanism which probably accounts for most of the effects observed in this paper.
The scientific study, "The distribution of breeding birds around upland wind farms", published in the Journal of Applied Ecology this week, was funded by RSPB Scotland, Scottish Government, Scottish Natural Heritage, and the Scottish Mountaineering Trust. Twelve major upland wind farms were surveyed six times during the breeding season for a dozen common species including waders and gamebirds (golden plover, lapwing, curlew, snipe, red grouse), raptors (buzzard, hen harrier, kestrel), and songbirds (skylark, meadow pipit, stonechat and wheatear).
The distribution of birds across each wind farm was compared with that on similar nearby sites without turbines. Seven species - buzzard, hen harrier, golden plover, snipe, curlew, wheatear and meadow pipit - were found less often than would be expected close to the turbines, indicating that breeding densities of these species are reduced by 15-53% within 500 m of the turbines. Amongst these, hen harrier and golden plover are protected under European law, and curlew is a high priority species under the UK Biodiversity Action Plan due to its population decline, so the loss of large areas of suitable breeding habitat is unacceptable.
Lead author James Pearce-Higgins, Senior conservation scientist with RSPB Scotland said:
"There is an urgent need to combat climate change, and renewable energy sources, such as wind farms, will play an important part in this. However, it is also important to fully understand the consequences of such development, to ensure that they are properly planned and sited. That is why we conducted this research which to our knowledge is the first multi-site assessment of the effect of wind farms on a wide range of upland bird species."
"What we've found is that a variety of bird species are indeed displaced with the impact extending up to 800 m from the wind turbines. This is a huge improvement in the evidence base that allows us now to better assess the likely impacts of future developments. Our results emphasise the need for wind farms to avoid areas with high densities of potentially vulnerable species such as curlews and golden plover, and help offer a way forward by informing the likely extent of positive habitat management which may help to offset the impacts of development. In conjunction with the Scottish wind farm sensitivity map which we produced three years ago, these findings will aid planners and responsible developers in enabling Scotland to meet its renewable energy targets and avoid the most sensitive sites for birds."
Andy Douse, Ornithological policy and advice manager with Scottish Natural Heritage said:
"SNH welcome the publication of this important paper, as it provides us with unequivocal evidence of both the nature and scale of bird displacement at operational wind farms. It will allow us to make better, more informed assessments of proposed wind farms in future and so reduce some of the uncertainty that has existed about potential impacts. It's an outstanding piece of careful research, and the authors are to be congratulated on the contribution that they have made to furthering our understanding of this contentious issue."
The full study is available for download here http://www.journalofappliedecology.org/view/0/upcomingIssue.html
More information on RSPB Scotland policy on wind farms, and the wind farm sensitivity map, are available here http://www.rspb.org.uk/ourwork/policy/windfarms/map.asp
RSPB Scotland believes that Scotland's energy needs can and should be met by renewable energy. For more information, see the Power of Scotland renewed report produced by RSPB Scotland along with Friends of the Earth Scotland, WWF Scotland and the World Development Movement here http://www.rspb.org.uk/Images/PowerofScotlandRenewed_tcm9-222405.pdf
Hen harrier and and golden plover are Annex I species under the EU Birds Directive, and thus have Special Protection Areas (SPA's) designated for them.