A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles

Field surveys in wetlands are limited by the difficulty accessing site, hazards during surveys, and risk of disturbing ecosystem. Thus, use unoccupied aerial vehicles (UAVs) can overcome these limiting factors assist monitoring small organisms, such as plants insects, that unique to wetlands, aiding wetland management conservation. This study aimed demonstrate effectiveness a survey method uses drone equipped with telephoto lens monitor dragonflies, which have been difficult quantitatively, especially large wetlands. In this study, main target species dragonflies was Nannophya pygmaea, is world’s smallest dragonfly (about 20 mm long). The area Mizorogaike (Kita Ward, Kyoto City, Japan). UAV flown at low speed an altitude 4 m 5 m, images were taken using 7× on Mavic 3 (7× optical 4× digital). A total 107 seven identified from photographs drone. N. about long, clearly identified. Eighty-five belonging pygmaea images. lens, captured, effects downwash noise reduced. proposed research be applied field, thus provide new important information pertaining highly useful for it non-invasive, does not require surveyor enter wetland, requires little effort, repeated.