It is currently known that loss in successional vegetation is leading to the decline of the New Holland mice, but it is also possible loss of plant species diversity is also a factor. Populations that became extinct did so very rapidly, between one and three years, however, recolonization were also very quick, average of .9 to 2 years. This suggests that there are many suitable habitats that can house these mice. In 1990, after many studies of small mammals in Victoria have been conducted, the Deakin University received $10,000 from the National Estate Grants Program to review the populations and distributions of the New Holland mouse, and to identify the processes of habitat modification which threatens the species. This research found that there are multiple populations in different areas that have already become extinct, there are still mice in some areas that are considered uninhabitable and those populations are decreasing, and that a lot of heath has been burnt leading to the extinction of certain populations.