A portable, comprehensive field guide--brimming with concise descriptions and stunning color photographs, and designed to fit into your back pocket--from the go-to reference source for over 18 million nature lovers. This National Audubon Society Pocket Guide gives full coverage to 80 of the most common and distinctive mammals in North America, from the Arctic to the Mexican border, and from the Atlantic coast to the Pacific.  An additional 30 important mammals are included under the heading "Similar Species," raising to 110 the total number of mammals described in this guide.