The Peterson Field Guide Series (R) Sponsored by the National Wildlife Federation, the Roger Tory Peterson Institute, and the National Audubon Society America's Best-Selling Field Guides THE PETERSON IDENTIFICATION SYSTEM Roger Tory Peterson's unique identification system explains exactly what features to look for to tell one species from another. EASE OF USE Peterson Field Guides are designed to work in the field, and every illustration, every word, is directed to that end. THE AUTHORS AND ILLUSTRATORS In each Peterson Field Guide, an author with expertise in the subject and an experienced artist work closely with the editors to ensure that both text and illustrations are accurate. A Field Guide to Animal Tracks, third edition This completely updated edition includes 100 color photographs of tracks and sign, more than 1,000 line drawings, and updated nomenclature for all the mammals of North America. The text includes descriptions of habits, habitats, tracks, sign