This paper a) gives an historical view of national parks and other protected areas since the 19th century, b) gives a history of national parks and nature reserves in NSW, c) shows how recent has been the recognition that fauna conservation depends upon protected areas, d) reflects how much has been achieved in the last 50 years, and e) considers what must be done to stop an ever–increasing list of our fauna becoming extinct, including identifying the crucial role of scientific study in this endeavour. The evolving debate of what burden protected areas should carry in conserving the nation's fauna is a central theme of this paper. The First World Congress on National Parks in 1962 produced ideals that are inspiring, connected and ecological. What was not apparent in 1962 was the scale of the problem of conserving the flora and fauna of the world. I present the case that the principles of protecting areas, fauna conservation and scientific research for nature conservation have been slow to take hold and uneasy in their political relationships as a land use option, but are now beginning to be seen as a key element in conserving a nation's wildlife. Protected areas, whether for wildlife, game, plants, ecosystems or scenery for public enjoyment, are a late competitor for large tracts of land. The historical account shows how distinct African, American, British and Australian protected area development has been, with common threads being how the ideal of protected areas is contested territory, and the linking over time of the concepts of fauna conservation and protected areas. The British story differs markedly from that in the USA and Africa. In 1943, a Nature Reserves Committee was appointed to draw up a rationale and list of National Habitat Reserves and Scientific Areas. Its report led directly to the appointment of the Nature Conservancy in 1949 charged with the establishment of National Nature Reserves, disseminating advice on nature conservation generally, and carrying out the research relevant to those responsibilities. These are crucial dates for the origin of nature reserves in Britain, the important role of research, and the central position of an ecological outlook on nature conservation, rather than the more limited label of preservation. Protected areas in Australia are often under–estimated, both for wildlife research and as havens for fauna populations, and for the research value of protected areas to conserve biodiversity in NSW. The published articulation of these values, and specifically the value of National Parks and Nature Reserves for research, is hard to find except in the recent literature. A review of the last four decades of published papers shows how much has changed in this short time. Given the long history of resistance to establishing protected areas, Australia's fauna is at an ever–increasing risk of extinction as natural habitats are relentlessly lost to economic growth and a rising human population. The problem, as I read the historical record, is that although we are learning fast, the loss of species, landscapes and ecosystems is happening even faster. From the First World Parks Congress in 1962 to today, the interpretation of the value of the national parks for fauna conservation remains contested, but the weight of historical and scientific opinion is ever stronger on the need for protected areas for conserving fauna.