Wind power is a promising renewable source of energy and wind farms are becoming increasingly more common. However, there is a concern for their impact on wildlife, in particular as collisions with them cause the deaths of thousands of bats and birds every year.

Based on previous work, a team of researchers led by Roel May from the Norwegian Institute for Nature Research set out to test whether painting one of the blades of the turbines would increase their visibility and reduce avian fatalities. They tested their prediction at a wind-power plant in the Smøla archipelago in Norway, an area designated to be Important Bird Area by Birdlife International, where researchers have collected avian fatality data since 2006.

Out of four turbines, one was painted black and the other three were left unpainted. Fatality data from searches at the base of the turbines over three-and-a-half years showed that black paint reduced the annual rotor blade fatality rate by 70 percent.

Birds of prey, such as the white-tailed eagle, benefited the most and accounted for the largest observed decline in death. The authors attribute this to the species' excellent vision.

Their data does not indicate that birds became familiar with the painted turbines. They say this is a good thing, as fatalities could increase if birds habituate to the changes.

These findings still need to be replicated in other studies. However, the authors suggest that such a strategy could be more easily put in practice before building the turbines, because painting blades with the turbines already set in place was a demanding task. As wind-power plants become more common, their impact should be reduced as much as possible. Painting their blades may be one way to go.