Behaviour 2019
Antipredator Behavior of Turkey Vultures in Response to UAS Varies by Platform
Morgan B. Pfeiffer1, Bradley F. Blackwell1, Thomas W. Seamans1, Bruce N. Buckingham1, Joshua L. Hoblet1, Esteban Fernández-Juricic2, Patrice E. Baumhardt2, Travis L. DeVault3. 1United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Sandusky, OH, United States; 2Purdue University, West Lafayette, IN, United States; 3University of Georgia, Aiken, SC, United States

One of the challenges conservation practitioners have is to manipulate the behavior of nuisance species to reduce their local abundance. The goal of this study was to assess the responses of turkey vultures to unoccupied aircraft systems (UAS) to disperse them. Our treatments included three platforms (fixed-wing, multirotor, and a predator-like ornithopter) and two approach types (targeted or overhead). We evaluated antipredator behavior in the context of reaction time, flight-initiation distance (FID), proportion of vultures remaining, and latency to return. Vultures escaped sooner in response to the fixed-wing; however, a lower proportion remained after multirotor treatments. Targeted approaches were perceived as more threatening than overhead. We found no effect of our treatments on FID or latency to return. Although, latency was negatively correlated with UAS speed. The ornithopter was the most salient, followed by the fixed-wing and multirotor. Despite its appearance, the ornithopter was comparably less effective. Since effectiveness varied in response to multirotor/fixed-wing treatments, we suggest their use be informed by logistics and management goals.