Aerial culling alters activity patterns but not grouping or movement in invasive fallow deer

Predation has been widely documented to impact prey behaviour, group dynamics and habitat selection, ultimately influencing individual fitness, population dynamics and even trophic cascades. Such outcomes could also occur when humans manage wildlife populations through lethal control, but lethal control techniques vary widely, making responses by the target species difficult to predict. Aerial or helicopter‐based culling is a common method used to kill animals over a large area, but little is known about how target species respond to the stimuli created by the sight and sound of the helicopter, the sound of gun shots and the disturbance related to conspecifics being shot in proximity. Here, we investigate the effects of aerial culling on invasive fallow deer ( Dama dama ) in an alpine region of south‐east Australia. We used two large‐scale remote camera arrays to monitor fallow deer temporal activity patterns, grouping and movement speed during and outside of aerial control periods. We found that aerial culling did not cause major changes in grouping or movement speed, however, the operations were linked to short term decreases in deer activity, particularly during the day, coupled with relative increases in activity for the dusk and night‐time periods. This suggests that fallow deer were shifting their diel activity patterns towards dusk during aerial culling. Synthesis and applications . Though a common technique employed for the control of medium‐ to large‐bodied invasive species, there is limited research on the effect of aerial culling on the target species from both a population and behavioural standpoint. In our study, aerial control induced short‐term temporal shifts in behaviour, suggesting future research could examine how management efforts can take advantage of this behaviour to achieve sustained population reductions.