There are more than 2,000 species currently listed as threatened or endangered under the Endangered Species Act. And while species that gain protection under the act have a great chance to survive, not all do. Just recently the U.S. Fish and Wildlife Service announced that 21 species – birds, fish, mussels, plants, and even a bat – were officially declared extinct. We're going to discuss that news, and the role of the Endangered Species Act in striving to prevent extinction, with Noah Greenwald, the endangered species director at the Center for Biological Diversity, and Lindsay Rosa, the vice president of conservation research and innovation at Defenders of Wildlife.