Mammals, Volume Five in the Hormones and Reproduction of Vertebrates series, is the fifth of five second-edition volumes representing a comprehensive and integrated overview of hormones and reproduction in fishes, amphibians, reptiles, birds, and mammals. The book includes coverage of endocrinology, neuroendocrinology, physiology, behavior, and anatomy of reptilian reproduction. It provides a broad treatment of the roles of pituitary, thyroid, adrenal, and gonadal hormones in all aspects of reproduction, as well as descriptions of major life history events. New to this edition is a concluding assessment of the effect of environmental influences on mammals. Initial chapters in this book broadly examine sex determination, reproductive neuroendocrinology, stress, and hormonal regulation as it relates to male and female reproductive structure and function. Subsequent chapters introduce the evolution of viviparity and examine pregnancy in eutherian mammals, parturition, pheromones, and behavioral neuroendocrinology. Covered taxa include rodents, bats, and primates. The book concludes with an examination of the environmental influences on hormones and reproduction of mammals, including endocrine-disrupting chemicals and climate change.