UAVs for Riverine Ecosystems
Aerial view of Gharial habitat in the Gandak River
Ganges river dolphins and gharials are two iconic species endemic to the Indo-Gangetic Basin. The endangered Ganges river dolphin, largely blind, uses ultrasonic waves for navigation and hunting. As mammals, they surface briefly to breathe every 3-5 minutes. Documenting these dolphins is challenging due to their brief surface appearances and the murky waters they inhabit. Gharials, distinguishable by the male's long snout, are critically endangered with their population highly impacted by habitat loss.
In this project, we collaborated with the Wildlife Conservation Trust’s (WCT) Riverine Ecosystems and Livelihoods Programme. We studied the two species using a combination of techniques over two field trips to the the Gandak in 2022 and 2023. Simultaneously collecting data through UAVs, boat- based visual methods and acoustically through CPODs allowed us to test and compare which techniques were best suited for different aspects of understanding the two species. This enables us to plan more efficient and information-rich surveys for the future. This project has been summarized as a case study for WeRobotics as well as experiential blogs (1,2) by the TfW team.
Building on our learning there, we returned to the Ganges in 2024. In this project, we used UAVs to collect video footage of dolphins in pre-identified hotspots. This data has been analysed to estimate the size and body condition of individual dolphins, findings of which will be published. Details of the methods we used to be able to analyse dolphin size using drone footage have been summarised in our technical blogs (3,4) .
