This book bridges the gap between physiology and ecology. It is organised into four major sections covering: temperature regulation; water relations; nutrition and energy; and reproduction and the environment. Each section discusses the physical and physiological principles involved in the topic and is supported by illustrative case studies. Readers of this fascinating account will learn: how starfish reproduce; why desert beetles collect water by basking in the fog; how bears synthesise protein during their winter torpor; why Bedouin goats are black; why humming birds spend so much time resting between foraging bouts; how marlin keep their brains warm and how cheethas cool their brains while sprinting.