Australian researchers have discovered they were inaccurately recording the amount of sea turtles at the world’s largest nesting site. Using drone technology, they found that they were underestimating numbers by more than 50 percent.

Scientists working to protect the endangered species had struggled with how best to keep track of the nesting turtles, but revealed in a paper published in peer-reviewed journal PLOS One last week that their new use of drones showed they had been underestimating numbers by more than 50 percent.