The key to solving a mystery is finding the right clues. Wildlife detectives aiming to protect endangered species have long been hobbled by the near impossibility of collecting DNA samples from rare and elusive animals. Now, researchers at Stanford and the National Centre for Biological Sciences at India’s Tata Institute of Fundamental Research have developed a method for extracting genetic clues quickly and cheaply from degraded and left-behind materials, such as feces, skin or saliva, and from food products suspected of containing endangered animals.