Can we improve the health and welfare of livestock while increasing production? Can we maintain animal biodiversity in the face of increasing demands for resources and expanding agriculture? Can we use animal behaviour to reduce the carbon footprint of livestock production? Applied ethology is a young, multidisciplinary science that is relevant to these and other pressing issues. This book celebrates the history and science of applied ethology, and commemorates the 50th anniversary of the International Society for Applied Ethology. Through themes such as human-animal interaction, play behaviour, cognition, evolutionary theory and the relationship between applied ethology and animal welfare science, the book examines why ethologists are so passionate about their work, and why this field remains more exciting now than ever. Chapter authors include world renowned ethologists such as Don Broom, Ian Duncan, Ruth Newberry, and many others. The history of the ISAE and development of the field is presented with engaging profiles of founding members and pioneers in the field. New methods and emerging issues in behaviour research are discussed, along with the development of ethology around the globe. The book concludes with thoughts on future directions for applied ethology in addressing global issues of animal production, welfare, biodiversity, and the role of the ISAE. The book provides an exciting overview of this emerging field of science, and is intended for academics, students and anyone who takes pleasure in observing animals.