Ecophysiology attempts to clarify the role and importance of physiological processes in the ecological relations of species in their natural habitats. Including blood collection and the measurement of plasma components and hormone levels, the basic principles and methods relevant to any ecophysiological study are covered in this text. Examples are collected from a wide range of vertebrates living in deserts, cold climates and oceans. The book is an introduction to ecophysiology for advanced students, as well as researchers in ecology, biodiversity and conservation.