Peterson Field Guide to Animal Tracks: Third Edition (Peterson Field Guides)
Mark Elbroch is author and coauthor of several guides to natural history. He is currently leading cougar projects in Southern Chile and the United States.Roger Tory Peterson, one of the world's greatest naturalists, received every major award for ornithology, natural science, and conservation as well as numerous honorary degrees, medals, and citations, including the Presidential Medal of Freedom. The Peterson Identification System has been called the greatest invention since binoculars. These editions include updated material by Michael O'Brien, Paul Lehman, Bill Thompson III, Michael DiGiorgio, Larry Rosche, and Jeffrey A. Gordon.