In The Pigs That Ate the Garden, Peter D. Dwyer examines the subsistence ecology of 109 Etolo people who live on the wet, forested mountain slopes of Papua New Guinea. Dwyer describes the community's practice of deliberately placing pigs in gardens so that the pigs depredate the vegetation there. He shows how this practice is actually the community's method of sending a message to itself that serves to resynchronize a switch from sweet potato gardening to sago starch processing. The interrelationships of the different food-producing activities of the Etolo—gardening, hunting, tree-crop cultivation, etc. —are shown to have seasonal rhythms, and these rhythms maximize the Etolo's use of food resources at appropriate times and areas. Dwyer argues that the "shape" of Etolo ecology is ultimately driven by sociocultural, rather than environmental, forces, and is set within a theoretical frame concerning processes of communication and change in open systems.