Roland W. Kays is the curator of mammals at the New York State Museum. Don E. Wilson is a senior scientist at the Smithsonian Institution's National Museum of Natural History. His books include The Smithsonian Book of North American Mammals and Mammal Species of the World. The best field guide to North American mammals The best-selling field guide that "sets new standards" (New Scientist) and "makes all other field guides for mammals of the United...