Using drones as ground-based camera systems with multiple coordinated sensors to study African elephants (Loxodonta Africana)

Advances in drone technology over the last two decades have enabled the collection of a wide variety of ecological data with increased accuracy while reducing overall costs (Watts et al. 2012; Christie et al. 2016; Hodgson et al. 2016; 2018). Elephants are ideal candidates for drone-based monitoring due to their size, making them easily visible from a height (Koh and Wich 2012). However, there are concerns over the potential for drone-generated noise, which induces a fear response in elephants due to its perceived resemblance to the sound of swarming bees, ultimately altering the behaviour of elephants under observation. Furthermore, the majority of commercially available drones have relatively short flying times of around 30 minutes before battery depletion occurs, which puts limits on the length of time that elephants can be studied from drones. This concept paper discusses a novel use case for drones in which their cluster of integrated sensors is used to collect valuable data on elephant physiology and morphology without the drone being airborne—and thus without generating any propeller noise. Additionally, it provides the advantage of longer observation periods than would be possible if the drone were flying. Here, we present this technique solely in the context of data collection on elephant physiology and morphology. The potential applications of this method are manifold and could extend to other species of appropriate size (e.g. rhinos) across different landscapes.