This book investigates how wild animals manage stress responses in natural environments, contrasting these findings with traditional laboratory-based models. John C. Wingfield and L. Michael Romero utilize their extensive backgrounds in endocrinology and behavioral ecology to synthesize field research. They argue that the physiological and behavioral mechanisms of stress are highly adaptive and must be studied within the context of unpredictable wild habitats rather than controlled settings.

Experts recognize this work as a significant contribution to the field of ecological endocrinology by shifting the focus from laboratory settings to natural habitats. Researchers frequently cite this text for its clear articulation of how wild animals navigate environmental pressures through complex physiological adaptations.