The measurement of metabolic rates is important in many areas of science. Examples range from ecology through a broad spectrum of physiological disciplines to biomedical fields such as genetic screening, obesity, and trauma research. The organisms being measured range in size from bacteria through insects to whales, and many different measurement methodologies have developed over the years, most of which are famously difficult for the novice to master. This book covers a wide range of metabolic measurement techniques, giving background and applications information for each, with enough practical detail to allow for accurate and informed measurements with minimal trial-and-error. Much tribal wisdom, passed down from professors to students and between scientific peers, is included. A broad range of techniques is covered, including Gilson and Warburg respirometry and their modern derivatives; direct calorimetry; stable isotope work; coulometric respirometry; aquatic respirometry; and practically every variation of field and laboratory flow-through respirometry, including complex, computer-driven multi-animal systems. Characteristics of the different varieties of gas analyzers, flow measurement systems, and so on are evaluated in detail. The book brings to the task over two decades of experience in practically every type of respirometry, from laboratory settings to the jungles of Panama and the deserts of Namibia.