Fiona A. Reid is a Departmental Associate in Mammalogy at the Center for Biodiversity and Conservation Biology at the Royal Ontario Museum. She is author and illustrator of Peterson Field Guide to Mammals of North America, Fourth Edition. Twan Leenders, a professional herpetologist and illustrator with more than ten years of field experience in Central America, is author of Guide to Amphibians and Reptiles of Costa Rica. Jim Zook is one of Costa Rica's most prominent ornithologists. Robert Dean is the illustrator of The Birds of Costa Rica: A Field Guide, also from Cornell.