Available for library use only and copying in accordance with the Copyright Act 1968, as amended. Thesis (PhD)--University of Tasmania, 2006. Includes bibliographical references. Ch.1. General introduction -- Ch.2. Sideroxylonal in Ecalyptus foliage influences foraging behaviour of an arboreal folivore -- Ch.3. Behavioral responses of a generalist mammalian folivore to the physiological constraints of a chemically defended diet -- Ch.4. Diet switching in a generalist mammalian folivore: fundamental to maximizing intake -- Ch.5. Spatial scale of the patchiness of plant poisons: a critical influence on foraging efficiency