Druid Drone—A portable unmanned aerial vehicle with a multifunctional manipulator for forest canopy and mistletoe research and management

Abstract

The forest canopy, as a biodiversity hotspot with many wildlife habitats, remains a difficult site to access for researchers and forest managers. Here, we present a novel, small, unmanned aerial vehicle, called the Druid Drone (DD), equipped with a multifunctional manipulator designed for tree crown management and biodiversity research. Its use is demonstrated by studies and the control of the widespread, obligatory hemiparasitic European mistletoe (Viscum album L.). The DD provides integrated pest management by canopy surveying, spraying and sampling of leaves/branches for further studies. The pilot and operator, using first person view goggles, handle the lightweight backpack-sized drone (DJI Mavic 2 Pro, Air 2, Phantom 3 or custom Rotorama quadcopter) equipped with a manipulator and five replaceable 3D-printed functional modules. These include the peripheral high-resolution Observer camera for close, non-invasive inspection of tree crowns, the entomological Collector unit for arthropod trapping, the forceps arm Sampler for soft plant tissue collection, the terminal Secator saw for cutting harder tree tissues such as twigs and the Green Doctor precision sprayer, which disperses growth regulators or other compounds for targeted tree and mistletoe management. This method offers a potential solution for safe, precise and minimally invasive research on forest canopy biodiversity in different forest types across the globe, tree health care and mistletoe management as compared to the manual work of arborists or the use of canopy cranes, forest helicopters and firearms.