Ian Hume is a nutritional physiologist who has made major contributions to the digestive physiology of domestic sheep and wild mammals. These include omnivorous bandicoots, leaf-eating possums and gliders, hindgut fermenting wombats, and foregut fermenting kangaroos. His 1982 monograph was the first synthesis of the marsupial field and stimulated much further research, much done by him and his students. This provided for the physiological base for ecological and behavioural studies, and provided the framework for conservation of several endangered marsupial species. His 1999 monograph is a masterly synthesis of marsupial nutrition and has confirmed him as world leader in comparative physiology.