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 in accessing the site, hazards during surveys, and the risk of disturbing the ecosystem. Thus, the use of unoccupied aerial vehicles (UAVs) can overcome these limiting factors and can assist in monitoring small organisms, such as plants and ins...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Drones |
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| Online Access: | https://www.mdpi.com/2504-446X/6/12/427 |
| _version_ | 1797460421641240576 |
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| author | Hideyuki Niwa Takumi Hirata |
| author_facet | Hideyuki Niwa Takumi Hirata |
| author_sort | Hideyuki Niwa |
| collection | DOAJ |
| description | Field surveys in wetlands are limited by the difficulty in accessing the site, hazards during surveys, and the risk of disturbing the ecosystem. Thus, the use of unoccupied aerial vehicles (UAVs) can overcome these limiting factors and can assist in monitoring small organisms, such as plants and insects, that are unique to wetlands, aiding in wetland management and conservation. This study aimed to demonstrate the effectiveness of a survey method that uses a small drone equipped with a telephoto lens to monitor dragonflies, which are unique to wetlands and have been difficult to survey quantitatively, especially in large wetlands. In this study, the main target species of dragonflies was <i>Nannophya pygmaea</i>, which is the world’s smallest dragonfly (about 20 mm long). The study area was Mizorogaike wetland (Kita Ward, Kyoto City, Japan). The UAV was flown at a low speed at an altitude of 4 m to 5 m, and images were taken using 7× telephoto lens on Mavic 3 (7× optical and 4× digital). A total of 107 dragonflies of seven species were identified from the photographs taken by the drone. <i>N. pygmaea</i>, about 20 mm long, was clearly identified. Eighty-five dragonflies belonging to <i>N. pygmaea</i> were identified from the images. Thus, by using a small drone equipped with a telephoto lens, the images of <i>N. pygmaea</i> were captured, and the effects of downwash and noise were reduced. The proposed research method can be applied to large wetlands that are difficult to survey in the field, and can thus provide new and important information pertaining to wetland management and conservation. This research method is highly useful for monitoring wetlands as it is non-invasive, does not require the surveyor to enter the wetland, requires little research effort, and can be repeated. |
| first_indexed | 2024-03-09T17:04:51Z |
| format | Article |
| id | doaj.art-bca4c11771c3441f9f63ecb0e39bc368 |
| institution | Directory Open Access Journal |
| issn | 2504-446X |
| language | English |
| last_indexed | 2024-03-09T17:04:51Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Drones |
| spelling | doaj.art-bca4c11771c3441f9f63ecb0e39bc3682023-11-24T14:25:32ZengMDPI AGDrones2504-446X2022-12-0161242710.3390/drones6120427A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial VehiclesHideyuki Niwa0Takumi Hirata1Faculty of Bioenvironmental Science, Kyoto University of Advanced Science, Kyoto 621-8555, JapanFaculty of Bioenvironmental Science, Kyoto University of Advanced Science, Kyoto 621-8555, JapanField surveys in wetlands are limited by the difficulty in accessing the site, hazards during surveys, and the risk of disturbing the ecosystem. Thus, the use of unoccupied aerial vehicles (UAVs) can overcome these limiting factors and can assist in monitoring small organisms, such as plants and insects, that are unique to wetlands, aiding in wetland management and conservation. This study aimed to demonstrate the effectiveness of a survey method that uses a small drone equipped with a telephoto lens to monitor dragonflies, which are unique to wetlands and have been difficult to survey quantitatively, especially in large wetlands. In this study, the main target species of dragonflies was <i>Nannophya pygmaea</i>, which is the world’s smallest dragonfly (about 20 mm long). The study area was Mizorogaike wetland (Kita Ward, Kyoto City, Japan). The UAV was flown at a low speed at an altitude of 4 m to 5 m, and images were taken using 7× telephoto lens on Mavic 3 (7× optical and 4× digital). A total of 107 dragonflies of seven species were identified from the photographs taken by the drone. <i>N. pygmaea</i>, about 20 mm long, was clearly identified. Eighty-five dragonflies belonging to <i>N. pygmaea</i> were identified from the images. Thus, by using a small drone equipped with a telephoto lens, the images of <i>N. pygmaea</i> were captured, and the effects of downwash and noise were reduced. The proposed research method can be applied to large wetlands that are difficult to survey in the field, and can thus provide new and important information pertaining to wetland management and conservation. This research method is highly useful for monitoring wetlands as it is non-invasive, does not require the surveyor to enter the wetland, requires little research effort, and can be repeated.https://www.mdpi.com/2504-446X/6/12/427dragonfly<i>Nannophya pygmaea</i> Ramburmonitoringwetlands |
| spellingShingle | Hideyuki Niwa Takumi Hirata A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles Drones dragonfly <i>Nannophya pygmaea</i> Rambur monitoring wetlands |
| title | A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles |
| title_full | A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles |
| title_fullStr | A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles |
| title_full_unstemmed | A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles |
| title_short | A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles |
| title_sort | new method for surveying the world s smallest class of dragonfly in wetlands using unoccupied aerial vehicles |
| topic | dragonfly <i>Nannophya pygmaea</i> Rambur monitoring wetlands |
| url | https://www.mdpi.com/2504-446X/6/12/427 |
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