Tree cavity inspector robots

Forest biodiversity is complex, and tree cavities, the small holes that look like small goiters on the trunks, have a surprisingly important role to play in maintaining biodiversity. In 2020, six Swiss scientists debuted a Micro Aerial Vehicle (MAV) equipped with a “dexterous manipulator” (robotic arm) to probe and implant a stereo camera that records information surrounding the camera in the tree cavity. The MAV is remotely guided to a tree and has a depth sensor mounted on the front to help distinguish between surface texture and depth, pinpointing and navigating to where cavities are on the tree. The arm then reaches out and places a stereo camera within the cavity. Tree cavities play host to a number of birds, insects, and transitory species that add to a forest’s rich biodiversity, but often in managed forests, such as those that link public streets or exist in parks, these cavities are trimmed to create a sense of visual uniformity; the impact of this on forests is detrimental. This MAV is specially kitted to explore these biodiversity crannies and bolsters research that encourages the validity of tree cavities and their necessity in managed forests because of their positive effect on biodiversity. However, there are a few unanswered questions about aspects of this research, particularly if or what the procedure is for retrieving the stereo cameras. Do researchers physically have to retrieve them or are they left for a prolonged period of time or are they simply abandoned? Are any animals prone to damaging, physically dislocating, or trying to ingest the camera? The impact of interfering with the species that live in the cavities and the impact of the research itself need to be closely considered and weighed against the benefits of retrieving data.

K. Steich, M. Kamel, P. Beardsley, M. K. Obrist, R. Siegwart and T. Lachat, “Tree cavity inspection using aerial robots,” 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Daejeon, 2016, pp. 4856-4862, doi: 10.1109/IROS.2016.7759713. Available at:


Artificial Life, Biodiversity, Ecological Monitoring, Monitoring, Visual Technologies