The Adaptation of Some Western Australian Mammals to Food Plants Containing Fluoroacetate.

The tolerance to fluoroacetate of Macropus fuliginosus, Trichosurus vulpecula and Rattus fuscipes from the south-west of Western Australia is unusually high. T. vulpecula and R. fuscipes from eastern Aus- tralia are much more susceptible than conspecifics from Western Australia. This tolerance appears to be an adaptation to the presence of monofluoroacetic acid in many species of the plant genera Gastrolobium and Oxylobium, which occur within the range of these mammals in Western Australia. The co-evolution of this defence mechanism in plants and the development of tolerance to fluoroacetate by herbivores is discussed.