Avian collisions with overhead power lines are a global conservation concern. Collisions are mitigated primarily through marking power lines to increase their visibility. Line marking is typically accomplished via an expensive and potentially dangerous process of hovering a helicopter within 1 m of a wire and installing line markers by hand. Unmanned Aerial Vehicles (UAVs) may offer a less dangerous, less costly alternative that is also less disturbing to wildlife. Herein we describe equipping a commercially available UAV with an installation arm designed in collaboration with the Colorado State University Department of Mechanical Engineering to install line markers on a power line. The UAV installed line markers within a 30 cm target window on a model power line. The proof of concept described here demonstrates the potential utility of UAVs in mitigating avian collision with overhead power lines.