One possible method to prevent birds colliding with a wind turbine is to increase the visibility of the rotating rotor blades. Experiments by Hodos (2003) showed that motion blur can be reduced by giving one of the blades a different colour.
This principle was recently studied by May et al. (2020) on the island of Smøla in Norway. That study revealed that painting one of the blades black reduced the number of collisions of white-tailed eagles by 70% (May et al., 2020)