Casey McFarland is a Senior Tracker and Evaluator for CyberTracker Conservation, a nonprofit organization that educates and certifies professional wildlife guides and amateur naturalists around the world. He is also a wildlife guide and naturalist. He coauthored the Peterson Field Guide to North American Bird Nests and Bird Feathers: A Guide to North American Species, and he contributed to Mark Elbroch’s Mammal Tracks & Sign: A Guide to North American Species. His website is https://www.caseymcfarland.net.