Feasibility study of monitoring using UAV for egrets in Lake Izunuma.

Abstract

In Lake Izunuma, Miyagi Prefecture, there is concern that the feeding habitats in the lakes of egrets is affected by the decreaseof open water and the change of fish composition. In this study, we examined the availability of UAV-based monitoring for egrets. The survey was conducted in Lake Izunuma (369 ha), and a total of 7,852 images were obtained using UAV in September 2018. Using the UAV imagery, the ability to discriminate egrets was examined. As a result, egrets were confirmed in 855 images, and UAV was considered available for monitoring egrets in lakes. To improve the efficiency of UAV monitoring, the availability of image analysis methods using binarization processing was evaluated. As a result, it was found that the binarization process is useful for screening UAV images. However it is difficult to extract only egrets, and further consideration of the method is necessary. UAV and image processing technologies were able to gather new insights of egrets. It is recommended that consider better protocols for UAV ecosystem monitoring.