Saving Bambi from the mower? Using a drone with thermal camera to evaluate a low‐tech scaring technique to reduce roe deer fawn mortality during grass harvest

Roe deer is a species that hides their neonates as an anti‐predator strategy. This may prove efficient against mammalian predators, such as the red fox; however, it might be an ecological trap as large numbers of fawns are killed by tractors with harvesters each year during grass harvest. Here, we evaluate a low‐tech, low‐cost method, using scaring flags placed in the field the evening before grass harvest, intended to stimulate the roe deer doe to remove any fawns from the field. We evaluate the effects of the scaring flags by counting the number of fawns in the fields using a multi‐rotor drone equipped with a thermal camera. The drone proved to be an efficient tool for detecting roe deer fawns. However, contrary to other studies, we found limited or no effect of placing the scaring flags in the field. This discrepancy highlights the fallacy of generalizing based on single case studies. There is still a need to develop low‐cost, easily applicable tools to reduce roe deer fawn mortality during grass harvest. However, with the increasing technological development, drones with thermal cameras are a promising tool for wildlife management and monitoring in the future.