At the time of European settlement in Australia in 1788, Magpie Geese (Anseranas semipalmata) were abundant, as they remain today, across northern Australia but were also common on swamps and on coastal and inland river floodplains in south-eastern Australia. However, by the early 1900s Magpie Geese had suffered a serious contraction of range from the south-east. In this study, we review all available records of the Magpie Goose and compile a list of processes potentially causing their decline. Historical changes in distribution are then compared with time frames of threatening processes to identify processes most likely to have driven the observed changes. The results suggest that the decline was primarily from loss of wetland habitat and hunting, although lesser threats such as poisoning, predation by Red Foxes (Vulpes vulpes) and severe drought may have increased the rate of decline. Since protection of the species from hunting in the 1930s in eastern and southern states and successful reintroductions in Victoria, New South Wales and South Australia, the species has returned to parts of its former range. However, populations are unlikely to return to their former numbers in the south-east as management of water resources has greatly reduced areas of breeding habitat and drought refuges. We suggest a program of management for southern populations of the Magpie Goose that includes long-term monitoring, engagement of landholders, identification and protection of existing wetlands, creation of new habitat, and reduction of disturbance from humans, introduced pests and livestock.