Effects of UAV overflight height, UAV type, and season on the behaviour of emperor penguin adults and chicks

The use of unmanned aerial vehicles (UAVs) increased during the last decade worldwide and in the pristine wilderness of the Antarctic continent. They are used by scientists from diverse fields, television and film crews, tourists, and station personnel. To protect Antarctic wildlife from potential disturbance, policy makers and national authorities require scientific information on the vulnerability of such species. Our study provides knowledge on the behavioural reaction to UAV overflights of emperor penguins (Aptenodytes forsteri) during crèche and fledge phase. We investigated three main questions: what is the influence of flight height, do two different UAV models (a quadcopter and a fixed-wing UAV) have different effects, and what is the influence of different times during the season. For adult penguins we found no differences between flight heights of 70 m or higher and control situations when flying with the quadcopter. Such a flight height without significant change in reactions in comparison to control could not be found for neither chicks (with both UAV models tested) nor adults during fixed-wing flights. In general, the behavioural reaction to the quadcopter was higher than to the fixed-wing UAV regarding proportions of individuals. The comparison of two times revealed a stronger reaction on the later time (end of December) than on the earlier (mid of November). In general, the reaction was not very intense with only small proportions of individuals changing their behaviour.