Darwin's work of 1872 still provides the point of departure for research in the theory of emotion and expression. Although he lacked the modern research tool of cybernetics, his basic methods have not been improved upon: the study of infants, of the insane, of paintings and sculpture, of some of the commoner animals; the use of photographs of expression submitted to different judges; and the comparative study of expression among different peoples. This new edition will be warmly welcomed by those behavioral scientists who have recently shown an intense interest in the scientific study of expression. Lay readers, too, will be struck by the freshness and directness of this book, which includes, among other data, Darwin's delightfully objective analysis of his own baby's smiles and pouts.

Along with reproduction, balancing energy expenditure with the limits of resource acquisition is essential for both a species and a population to survive. But energy is a limited resource, as we know well, so birds and mammals—the most energy-intensive fauna on the planet—must reduce energy expenditures to maintain this balance, some taking small steps, and others extreme measures.

Here Brian K. McNab draws on his over sixty years in the field to provide a comprehensive account of the energetics of birds and mammals, one fully integrated with their natural history. McNab begins with an overview of thermal rates—much of our own energy is spent maintaining our 98.6?F temperature—and explains how the basal rate of metabolism drives energy use, especially in extreme environments. He then explores those variables that interact with the basal rate of metabolism, like body size and scale and environments, highlighting their influence on behavior, distribution, and even reproductive output. Successive chapters take up energy and population dynamics and evolution. A critical central theme that runs through the book is how the energetic needs of birds and mammals come up against rapid environmental change and how this is hastening the pace of extinction.