The Sunday Herald can reveal a white-tailed sea eagle, reintroduced as part of a nature conservation programme, was found dead in February at Burnfoot Hill wind farm in the Ochil hills, near Tillicoultry in Clackmannanshire. A post-mortem examination by Government-approved scientists concluded a "likely cause of death" was collision with a wind turbine.
Eagles have been killed by wind farms in Germany and Norway before, but no deaths have previously been recorded in Scotland. Conservationists stress that many more eagles are killed by landowners, gamekeepers, power lines and trains, but evidence that a sea eagle has now died after crashing into a wind turbine is likely to trigger renewed questions about where wind farms should be sited.
Sea eagles were driven to extinction in Scotland early in the 20th century, and have been reintroduced from Norway in a series of Government-backed releases beginning in the 1980s. Bigger than golden eagles, they are the UK's largest bird of prey, with between 37 and 44 pairs now successfully breeding.
The dead sea eagle, known as Red T, was a male released in the east of Scotland in 2011. His body was found three months ago under a layer of snow beneath a wind turbine at Burnfoot Hill, which was developed by the Bristol-based company, Wind Prospect, and is owned and run by the French state enterprise, EDF Energy Renewables.
The RSPB commissioned vets from Scotland's Rural College, which also works for the Scottish Government, to conduct a post-mortem. Their investigation ruled out death by poisoning, and discovered that two bones in the bird's left leg were broken.
"Dark discolouration" around the head and neck suggested that the eagle had suffered trauma, the post-mortem report said. "Trauma consistent with, but not limited to, collision with a wind turbine has been recorded as the likely cause of death," it concluded.
The death was "very disappointing", said Aedán Smith, head of planning and development at RSPB Scotland. "This tragic incident serves as a stark reminder of the importance of ensuring wind farms are carefully planned to avoid our best places for wildlife."
He said the RSPB was increasingly concerned about the number of applications for wind turbines in areas that, unlike the Ochils, were known to be important for eagles.
However, Smith pointed out that white-tailed sea eagles, Scotland's biggest birds of prey, were far more likely to be killed by other causes. According to RSPB figures, since 2007, six had been killed by trains, eight by power lines and at least six illegally poisoned or shot.
The number which died because of illegal persecution may be much higher as cases can easily go undetected, the RSPB stressed.
Ron Macdonald, policy director with the government's wildlife agency, Scottish Natural Heritage, said: "Evidence has been growing from Europe that white-tailed eagles are fairly vulnerable to collision with wind turbines. Clearly we have to monitor the situation closely here."
EDF Energy Renewables confirmed that "regrettably" a white-tailed sea eagle had been found dead at Burnfoot Hill, which has 13 100-metre high turbines.
The company's head of asset management, Nick Bradford, said: "We take the utmost care in selecting potential sites and undertake extensive environmental studies including bird habitat and migration routes before constructing our wind farms.
"We will be working closely with RSPB and environmental consultants to determine what lessons can be learned and what might be done to prevent such incidents occurring in future."
A Scottish Government spokesperson said: "The loss of any sea eagle is extremely disappointing, when so many people have worked so hard to bring back the species to Scotland."