Proceedings of the Vertebrate Pest Conference

Heron streamers/droppings, which are electrical conductors, have caused power outages at electrical substations and transmission towers. It is necessary to understand the effectiveness of techniques for scaring herons to prevent electrical outages caused by their streamers. Here, we focused on bird-management techniques using visual deterrents and evaluated the deterrent effects of light-emitting diodes (LED), lasers, and a robotic approach. Grey herons were observed on the outdoor steel structure of the High Power Testing Laboratory of the Central Research Institute of the Electric Power Industry in Yokosuka, before and after dawn. LED lights were attached to the uppermost steel structure of the laboratory to evaluate the deterrent effects. A green laser was installed 60 m north of the steel structure. The lights and laser were fired manually when herons landed on the steel structure and we evaluated the response of the birds to the stimuli. We also installed a commercial mobile robot, which was programmed to move underneath the steel structure after dawn. To investigate the deterrent effect of the size of the robot, we put a scarecrow on the robot and compared the proportions of herons deterred by the robot with and without the scarecrow. Both the LED and laser were effective before dawn, but their deterrent effects decreased significantly as the ambient illuminance increased. In the robot experiment, more than 78% of the herons were deterred from the steel structure when the scarecrow was attached, while less than 6% of the herons were deterred when we used the robot without the scarecrow. Our findings suggest the effectiveness of visual scaring techniques for herons. Bird-management strategies combining LED, lasers, and robots may be useful for deterring herons during both the day and night.