We found a dead blackbird in the front garden, no obvious sign of injury, so it could have been anything. Then a week later we found a pigeon in the back garden, directly below the turbine, with a slightly more obvious means of death - its head was missing. Blood splatters on the nearby fence indicated that the pigeon was bleeding as it was falling, which pins the blame squarely on the turbine.
We took the pictures of the pigeon after relocating it to the compost heap. We should bury it, really.