Many developing countries -- especially in Asia -- host thriving pet markets such as this bird market on the Indonesian island of Sumatra (left) filled with wild-caught animals. Birds such as the Oriental white-eye (right) are packed into tight cages where they are at risk of disease. Many Asian and African countries host a startling number of species yet have lax-to-nonexistent monitoring and conservation programs. The Princeton researchers' market-monitoring method can be done far more quickly and cheaply than field-based monitoring of wild populations.
Photos by Tomas Busina, Indonesia Species Conservation Program, and David Wilcove, Department of Ecology and Evolutionary Biology