Tony D. Williams is professor of biological sciences at Simon Fraser University and a fellow of the American Ornithological Society. He is the author of Physiological Adaptations for Breeding in Birds (Princeton) and The Penguins. Scott McWilliams is professor of wildlife ecology and physiology at the University of Rhode Island. Julia A. Clarke is the John A. Wilson Professor in Vertebrate Paleontology at the University of Texas at Austin. Elizabeth MacDougall-Shackleton is professor of biology at Western University in Ontario. Scott MacDougall-Shackleton is chair of the Department of Psychology at Western University in Ontario. Frances Bonier is a field biologist with a research focus on the ways animals respond to diverse challenges, including parasites, urbanization, and climate change. Chad Eliason is a postdoctoral fellow at the Field Museum of Natural History in Chicago.