Assessing physiological and behavioural impacts of unmanned aerial vehicles on chinstrap penguin chicks: an experimental approach

Protecting animals from anthropogenic influences is important in vulnerable ecosystems such as Antarctica. A potential recent activity affecting Antarctic wildlife is the use of unmanned aerial vehicles (UAVs). Previous studies in this area have mainly focused on animal behavioural observations and have reported reactions to UAVs in many cases. To gain insights into the influence of UAVs on physiology (stress hormones) in addition to behavioural reactions, we conducted an experiment on chinstrap penguin chicks ( Pygoscelis antarcticus ) on the South Shetland Islands (Antarctica) during the breeding season of 2017–2018. Using a small quadcopter UAV, we performed flights over groups of penguin chicks in the early crèche phase using ‘Hard’ and ‘Soft’ treatment setups (15 and 50 m above the penguins, respectively). The behavioural observations revealed clear reactions to the UAV during the Hard treatment, but we could not find an association between such UAV activity and stress hormone levels. As we cannot clearly disentangle the effects of handling during blood sampling and the direct influence of the UAV, we conclude that the physiological impact of overflights at 15 m ranges from no impact to a maximum impact equal to the impact associated with animal handling. During the Soft treatment (UAV overflights at 50 m), no behavioural or physiological effects were detected.