Bears Show a Physiological but Limited Behavioral Response to Unmanned Aerial Vehicles

Abstract

Unmanned aerial vehicles (UAVs) have the potential to revolutionize the way research is conducted in many scientific fields. UAVs can access remote or difficult terrain, collect large amounts of data for lower cost than traditional aerial methods, and facilitate observations of species that are wary of human presence. Currently, despite large regulatory hurdles, UAVs are being deployed by researchers and conservationists to monitor threats to biodiversity, collect frequent aerial imagery, estimate population abundance, and deter poaching. Studies have examined the behavioral responses of wildlife to aircraft (including UAVs), but with the widespread increase in UAV flights, it is critical to understand whether UAVs act as stressors to wildlife and to quantify that impact. Biologger technology allows for the remote monitoring of stress responses in free-roaming individuals, and when linked to locational information, it can be used to determine events or components of an animal's environment that elicit a physiological response not apparent based on behavior alone. We assessed effects of UAV flights on movements and heart rate responses of free-roaming American black bears. We observed consistently strong physiological responses but infrequent behavioral changes. All bears, including an individual denned for hibernation, responded to UAV flights with elevated heart rates, rising as much as 123 beats per minute above the pre-flight baseline. It is important to consider the additional stress on wildlife from UAV flights when developing regulations and best scientific practices.

Using drones as a monitoring tool to detect evidence of winter sports activities in a protected mountain area

“…However, in order for this tool to be superior to conventional methods like fieldwork on foot, it is a precondition that there should be no, or only very little, disturbance to wildlife. In this study, no wildlife movements were observed and hence disturbance was considered low, a finding that has been observed in other contexts (Ditmer et al 2015;SardaPalomera et al 2012;Vas et al 2015). To draw a general conclusion from this result, how ever, would be risky as it is known that the aeronautical settings of the flights are critical.…”

“…In recent years, they have proven good tools for monitoring large sensitive areas in a lowcost manner (Jones et al 2006;Weissensteiner et al 2015). The impact on wildlife from drone flights is, furthermore, reported to be quite low (Ditmer et al 2015;SardaPalomera et al 2012;Vas et al 2015).…”

The Use of Unmanned Aerial Systems in Marine Mammal Research

“…Despite their value for research, concerns have been raised regarding the risk of harassment for the targeted animals (e.g., [5,13,64]). Consequently, scientific best practices for the use of UAS in wildlife surveys are being developed in order to minimize the disturbance levels.…”

An assessment of thermal-image acquisition with an unmanned aerial vehicle (UAV) for direct counts of coastal marine mammals ashore

“…The most common and accepted method of counting individuals, mark-recapture, requires large teams of researchers walking amongst the target animal population, manually counting individuals over multiple days. These ground surveys are labour intensive and costly, and can create disturbances within the population being sampled, as well as among populations of non-target species (Ditmer et al 2015). For large migratory animals, researchers may substitute walking for an aircraft; further increasing the survey cost.…”