Chitwan, Nepal – August 23, 2025
A groundbreaking study has shown how drone technology can transform wildlife conservation, offering new hope for monitoring endangered crocodile species in Nepal’s river systems.
Researchers deployed a Wingtra VTOL drone to survey a 73-kilometer stretch of the East Rapti River inside Chitwan National Park, home to the country’s largest populations of gharials (Gavialis gangeticus) and mugger crocodiles (Crocodylus palustris). Over the course of the winter basking season, the drone captured more than 24,000 high-resolution images, enabling precise population counts and habitat mapping.
The survey identified a total of 323 crocodiles, including 205 gharials-a critically endangered species-and 118 muggers. Data analysis revealed that gharials had a habitat-use probability of 0.47, while muggers showed a probability of 0.24. Interestingly, a spatial interaction factor of 1.94 suggested that both species frequently share the same river habitats, highlighting ecological overlap and coexistence.
Beyond ecological insights, the study also emphasized the efficiency of drone-based monitoring. Compared to traditional ground surveys, drones proved to be approximately 34 times more cost-effective, with operational costs estimated at just US$0.61 per kilometer-a dramatic reduction from the conventional US$21 per kilometer.
Researchers argue that integrating drone monitoring with machine learning tools for automated image analysis could revolutionize large-scale ecological studies, particularly in South Asia’s vast river systems where logistical challenges often hinder conservation efforts.
“This approach offers a precise, cost-effective, and less labor-intensive way to safeguard endangered aquatic species,” the authors note, adding that drone-assisted monitoring could play a pivotal role in long-term strategies for gharial and mugger conservation.
The findings underscore the potential of technology-driven conservation methods at a time when gharial populations remain critically low and under constant threat from habitat loss, fishing pressures, and river pollution.
