The Cost of Living: Field Metabolic Rates of Small Mammals

The chapter begins with an overview of cost of living based on field metabolic rates of small mammals. The chapter then goes on to discuss the importance of energy in living systems, limitations on animal energy expenditure, the extrinsic limitation hypothesis, the intrinsic limitation hypothesis, experimental studies of the limitation hypotheses, the central limitation hypothesis and links between field metabolic rate (FMR) and resting metabolic rate (RMR), interspecific reviews of the link between daily energy expenditure (DEE) and RMR, and also gives summary and aims of the chapter. Methods section proposes to review the methods available for measurement of energy expenditure by mammals, in particular, the method of indirect calorimetry and the field techniques of time and energy budgeting and doubly labelled water, and also direct measurements of free-living energy expenditure. It also gives summary and data inclusion criteria for the present review. The chapter has also discussed results and provided an overview of database studied and has described factors influencing daily energy expenditure in mammals. The chapter closes with discussion about links between FMR and RMR and sustainable metabolic scope.