Lack of evasive behaviour by a Martial Eagle Polemaetus bellicosus on impact with a turbine blade at a South African wind farm: causes and mitigations

We describe a collision of Africa’s largest raptor, the Martial Eagle Polemaetus bellicosus with a spinning blade at a South African wind farm in the Eastern Cape in July 2016, and the abandonment of the territory following a second fatal collision of an adult Martial Eagle at the same farm. Most evidence suggest that the eagle took no evasive action because she did not detect the blade due to the poor contrast abilities among raptors in general. Increasing blade visibility with black or “Signal Red” stripes is a simple and promising cost-effective mitigation action that should be further tested in South African wind farms.