John F. Eisenberg is Katharine Ordway Professor of Ecosystem Conservation at the Florida Museum of Natural History, University of Florida. He is the author of The Mammalian Radiations and of Mammals of the Neotropics, volume 1, and coauthor of Mammals of the Neotropics, volume 2. Kent H. Redford is director of biodiversity analysis and coordination at the Wildlife Conservation Society. He is the coauthor of Mammals of the Neotropics, volume 2, and coeditor of Neotropical Wildlife Use and Conservation.