Brazil - August 07, 2025 Amazon River, Brazil - A groundbreaking study by the Wildlife Conservation Society (WCS) and the University of Florida has confirmed the largest known gathering of freshwater turtles in the world. Over a 12-day nesting season along the Amazon’s Guaporé River, more than 41,000 Giant South American River Turtles (Podocnemis expansa) were counted using innovative drone technology. The research, published in the Journal of Applied Ecology, introduced a new method combining drone imagery with advanced statistical models. This approach corrects for errors such as double counts and undetected turtles, offering a more accurate estimate of wildlife populations. “This is a major leap forward in how we monitor wildlife populations,” said Dr. Camila Ferrara, WCS Brazil aquatic turtle specialist. “By using drones and correcting for detection errors, we can now better understand the dynamics of these critical nesting events.” Dr. German Forero-Medina, Science and Conservation Director for WCS Colombia, added, “We move beyond using drones just to document this wonderful event to developing rigorous methods to estimate turtle population size and trends over time.” Traditional ground counts often face challenges like limited visibility and difficult terrain. Using drones, researchers created detailed aerial images of the nesting sites and applied a mark-resight method to estimate the true number of turtles. “This method provides a powerful way to monitor large animal populations in remote areas like the Amazon,” said Ferrara. “Accurate estimates are critical for effective conservation planning.” The study’s methods can be adapted for other species, from migratory birds to marine mammals, where group counts have been difficult. WCS collaborates with local communities and governments to protect the Giant South American River Turtle and its habitat. These turtles, the largest freshwater species in Latin America, reach up to 3.5 feet in length and 200 pounds. They play an essential role in seed dispersal and contribute significantly to the river’s food web.