First guidelines and suggested best protocol for surveying African elephants (Loxodonta africana) using a drone

Wildlife science usually focusses on the study, monitoring and management of animals and their habitats (Chabot & Bird 2015). Although these goals may be relatively simple, achieving them can be extremely challenging, particularly as resources are often limited and target species can be elusive, wide-ranging, sensitive to anthropogenic disturbances and/or dangerous to approach (Chabot & Bird 2015). Additionally, many target animals occupy habitats that are extensive, remote and often impossible to access at ground-level. New technologies have greatly aided accessing these difficult subjects in their challenging habitats. Examples include motion-triggered camera traps (O’Connell, Nichols & Karanth 2011), aircraft (Fleming & Tracey 2008), remote sensing satellites (Kerr & Ostrovsky 2003), radar (Larkin 2005), thermal cameras (O’Neil et al. 2005), projectile-based animal-capturing devices and chemical immobilisation agents (Roffe, Sweeney & Aune 2005; Schemnitz 2005) and a vast array of electronic tracking devices and accompanying software (Thomas, Holland & Minot 2011). One technology that is rapidly gaining popularity are the aerial units known variously as unmanned aircraft systems (UAS), unmanned aerial vehicles (UAV), remotely piloted aircraft systems or (mostly popularly) drones. The popularity of drones amongst wildlife biologists, ecologists and conservationists is clear from the many review articles investigating the applications and proliferation of drone use in remote sensing, natural resource sciences and ecology (Allan et al. 2015; Anderson & Gaston 2013; Christie et al. 2016; Colomina & Molina 2014; Jones, Pearlstine & Percival 2006; Koh & Wich 2012; Pajares 2015; Shahbazi, Theau & Menard 2014; Watts, Ambrosia & Hinkley 2012; Whitehead & Hugenholtz 2014; Whitehead et al. 2014). Chabot and Bird (2015) conducted an extensive review of drone use in wildlife management in which they highlighted optical surveying and observation of animals, uses of drones in autonomous wildlife telemetry tracking, habitat research and monitoring and a review of the broader potential for UAVs. Although the capabilities and Unmanned aerial vehicles, commonly known as drones, are increasingly used in ecological management, conservation and research. Numerous reviews on drones tout almost unlimited potential within the wildlife sciences as they open up inaccessible habitats to observation. However, the influence of drones on the animals themselves is far less understood, and impact studies to construct protocols for best practices are urgently needed to minimise the potential for stress on target species. The impact of a quadcopter drone’s approach speed, angle of approach and initial starting altitude was tested on the behavioural responses of African elephants (Loxodonta africana), along with sustained speed and flight pattern. Seventy-nine approach flights and 70 presence flights were conducted. The speed and angle of approach significantly impacted the success of a flight, but neither speed nor flight pattern had any measurable impact on elephants’ behaviour during sustained flights. It is recommended that drones be launched at a distance of 100 m from an elephant or a herd of elephants, ascending to a height of 50 m by using an approach speed of 2m/s and an approach angle of 45 ° or less to successfully contact elephant targets.