Dr. Mark Elbroch is a recognized expert on wildlife tracking. A Senior Tracker certified by Cyber Tracker Conservation, he is Lead Scientist for the Puma Program for Panthera, www.panthera.org, and Lead for the Teton Cougar Project in Patagonia. Mark's work with mountain lions has been featured on BBC and his work in North America continues to break ground on mountain lion community ecology. He has authored and coauthored ten books on wildlife tracking and natural history and has won the National Outdoor Book Award for his field guides, including the first edition of Mammal Tracks & Sign. He is a regular contributor to National Geographic's News Blog and a regular guest on NPR. He lives in Sequim, Washington. Casey McFarland is a Senior Tracker certified by Cyber Tracker Conservation and a Senior Cyber Tracker Evaluator. He works internationally to train and certify biologists, research teams, and the public and runs courses on track and sign identification throughout the world. His is coauthor of Bird Feathers (Stackpole, 2010) and Peterson Field Guide to North American Bird Nests (to be released in 2019). He lives in Cedar Crest, New Mexico.