Drones, sensors, and their potential utility for mountain sheep surveys

Unmanned aerial vehicles (UAV), often referred to as unmanned aerial systems (UAS) or drones, are experiencing increasing use by wildlife researchers and for a variety of purposes. When equipped with one or more of the various sensors currently available, these remotely operated platforms are being used to conduct aerial surveys of large mammals occupying a diversity of ecosystems, but more so for species that occupy terrain that is neither as rugged nor topographically extreme as that occupied by mountain sheep. Despite some of the potential advantages offered by this technology, UAVs have not been used extensively to survey populations of mountain sheep. In this paper, we provide some background information regarding the (1) utility of these platforms to survey mountain sheep; (2) types of unmanned aerial vehicles currently available; (3) types and limitations of currently available sensors; (4) factors that complicate use of these technologies specifically for surveys of mountain sheep populations; and (5) some additional suggestions, including ways to mitigate some of those complications. For reasons enumerated herein, these aerial platforms and associated sensors currently are used sparingly in mountain sheep habitat, but we predict use will increase substantially as a result of technological advances and the human safety advantages associated with these devices.