Researchers have discovered what may be the largest reptile nesting site ever recorded, after documenting more than 41,000 giant river turtles gathering to lay eggs along a remote stretch of the Guaporé River in the Amazon basin. The remarkable discovery was made using drone technology, offering scientists a new way to accurately monitor large wildlife populations.
The study, conducted by researchers from the University of Florida and the Wildlife Conservation Society, focused on the endangered Giant South American river turtle, one of the largest freshwater turtles in the world. The findings were published in the Journal of Applied Ecology.
Drone technology reveals massive turtle gathering
Each year, female giant river turtles gather in huge numbers on sandy riverbanks to lay eggs during the breeding season. The newly documented nesting site lies along the Guaporé River, which forms part of the border between Brazil and Bolivia.
Using drones, scientists captured thousands of aerial photographs of the nesting beaches. The images were then combined into high-resolution composite maps, allowing researchers to track turtle movements and estimate the true population size.
Lead researcher Ismael Brack explained that the new method helps overcome long-standing challenges in wildlife surveys. Traditional ground counts can be slow and inaccurate, while aerial images sometimes lead to animals being counted twice or missed altogether.
To improve accuracy, the research team marked the shells of 1,187 turtles with white paint and monitored them over a 12-day period. Drones flew over the nesting site four times daily, capturing around 1,500 images during each flight.
New counting method reveals more accurate estimate
The study revealed dramatic differences between counting methods. Ground observers recorded around 16,000 turtles, while researchers analyzing drone images without correcting for movement counted nearly 79,000 animals.
By combining drone imagery with statistical modelling, the team produced what they believe is the most accurate estimate yet — approximately 41,000 turtles nesting at the site.
Scientists say such accurate population estimates are essential for conservation planning. Without reliable data, it becomes difficult to determine whether a species is recovering or declining.
Key species for the Amazon ecosystem
The giant South American river turtle can grow up to 90 centimetres in length and weigh as much as 80 kilograms. It inhabits large rivers throughout the Amazon Basin and the Orinoco River Basin.
Despite legal protections, the species remains threatened by illegal egg harvesting, poaching and habitat loss. Conservationists consider nesting beaches particularly important, as thousands of turtles depend on them each year to reproduce.
Beyond their ecological importance, the turtles also play a role in maintaining healthy river ecosystems by dispersing plant seeds and serving as prey for larger animals.
Future conservation efforts
Researchers believe drone-based monitoring could transform wildlife conservation, allowing scientists to track large animal populations more accurately and with minimal disturbance.
The team plans to expand the method to other turtle nesting areas across the Amazon region, including locations in Colombia, Peru and Venezuela.
Scientists say that combining drone technology with improved statistical models will help conservation groups detect long-term population trends and better protect endangered species across the region.