Mammals in the genus Martes are mid-sized carnivores of great importance to forest ecosystems. This book, the successor to Martens, Sables, and Fishers: Biology and Conservation, provides a scientific basis for management and conservation efforts designed to maintain or enhance the populations and habitats of Martes species throughout the world. The twenty synthesis chapters contained in this book bring together the perspectives and expertise of sixty-three scientists from twelve countries, and are organized by the five key themes of evolution and biogeography, population biology and management, habitat ecology and management, research techniques, and conservation. Recent developments in research technologies such as modeling and genetics, biological knowledge about pathogens and parasites, and concerns about the potential effects of global warming on the distribution and status of Martes populations make new syntheses of these areas especially timely. The volume provides an overview of what is known while clarifying initiatives for future research and conservation priorities, and will be of interest to mammalogists, resource managers, applied ecologists, and conservation biologists.