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, signs, and ranges and is filled with wonderful natural history stories.

Olaus J. Murie was one of America's leading mammalogists. His extensive fieldwork ranged throughout the United States and Canada, from Labrador to the Aleutian Islands, with special concentration in the Northwest. For twenty-five years he was a field biologist with the U.S. Biological Survey, now the U.S. Fish and Wildlife Service. He also served as director of the Wilderness Society for many years. Murie lived in Moose, Wyoming. He was the author of The Elk of North America and many articles on natural history.

 
Mark Elbroch is the author of several tracking guides, including two award-winning books, Mammal Tracks and Sign: A Guide to North American Species and, with Eleanor Marks, Bird Tracks and Sign: A Guide to North American Species. He has contributed to numerous North American research projects, from monitoring bears to capturing cougars to inventorying carnivores in dry tropical forests. He is working with Cybertracker Conservation in South Africa to create the first North American evaluation for wildlife trackers. Elbroch currently works as a wildlife consultant, specializing in field inventories and identifying corridors, and teaches workshops on wildlife and tracking across North America.