Growing recognition of the complexity of animals' physical, social, and psychological lives in the wild has led both zookeepers and the zoo-going public to call for higher environmental standards for animals in captivity. Bringing together the work of animal behaviorists, zoo biologists, and psychologists, this book explores a range of innovative strategies for environmental enrichment in laboratories and marine parks as well as in zoos. Moving beyond the usual studies of primates to consider the requirements of animals as diverse as reptiles, amphibians, marine mammals, small cats, hooved grazers, and bears, contributors argue that whether an animal forages in the wild or plays computer games in captivity, the satisfaction its activity provides - rather than the activity itelf - determines its level of physical and pyschological well-being. Second Nature also discusses the ways in which environmental enrichment can help zoo-bred animals develop the stamina and adaptability for reintroduction into the wild, and how it can produce healthier lab animals that yield more valid test results. Providing a theoretical framework for the science of environmental enrichment in a variety of settings, the book renews and extends a humane approach to the keeping and conservation of animals.