 On 7 February 1959 Gillham left for a Tasmanian tour.She also spent the three summers of 1958–1960 at Tasmania investigating (as part of a team) the costs and benefits of pastoral farming and muttonbird harvesting, residing at a research hut on Fisher Island, in the Eastern Bass Strait between Tasmania and mainland Australia.In December 1959 Mary Gillham, along with Susan Ingham (British), Hope Macpherson and Isobel Bennett (both Australian), became the first female scientists to join a research trip to Macquarie Island, Antarctica with ANARE (Australian National Antarctic Research Expedition).