Getting from here to there may be simple for one individual. But as any parent, scout leader, or CEO knows, herding a whole troop in one direction is a lot more complicated. Who leads the group? Who decides where the group will travel, and using what information? How do they accomplish these tasks? "On the Move" addresses these questions, examining the social, cognitive and ecological processes that underlie patterns and strategies of group travel. Chapters discuss how factors such as group size, resource distribution and availability, the costs of travel, predation, social cohesion and cognitive skills affect how individuals as well as social groups exploit their environment. Most chapters focus on field studies of a wide range of human and nonhuman primate groups, from squirrel monkeys to Turkana pastoralists, but chapters covering group travel in hyenas, birds, dolphins and bees provide a broad taxonomic perspective and offer new insights into comparative questions, such as whether primates are unique in their ability to coordinate group-level activities.