Hen harrier are among species researchers believe affected
Some of Scotland's rarest birds are being displaced by wind turbine developments, a study has suggested.
Hen harriers and golden plovers were among the birds found to be breeding in fewer numbers close to wind farm sites.
RSPB Scotland, which part-funded the study, said the findings showed turbines should not be sited near vulnerable bird populations.
The research, newly published in the Journal of Applied Ecology, looked at 12 upland wind energy sites in the UK.
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 frequently than would be expected close to the turbines.
RSPB Scotland said breeding densities of these species were reduced by between 15% and 53%, within 500m of the turbines.
However, lead author James Pearce-Higgins, senior conservation scientist with RSPB Scotland, said the displacing of species could extend as far as 800m.
He 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."
Andy Douse, ornithological policy and advice manager with Scottish Natural Heritage, said it was an outstanding piece of research.
He said: "SNH welcome the publication of this important paper, 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."
The research was funded by RSPB Scotland, the Scottish government, Scottish Natural Heritage and the Scottish Mountaineering Trust.