Impact of Habitat Loss and Fragmentation on Assemblages, Populations, and Individuals of Australasian Marsupials

Australasia is home to many iconic species of marsupials, most found nowhere else. The region also leads the world in marsupial declines and extinctions. There are many causes of marsupial decline with focus in this chapter on habitat loss and habitat fragmentation. While habitat loss and habitat fragmentation are typically considered together, they are actually separate processes. However, many landscapes are subject to the simultaneous, co-occurring effects of both habitat loss and habitat fragmentation. In this chapter, some of the key human-generated factors contributing to habitat loss and habitat fragmentation for Australasian marsupials are outlined. This is done by providing a brief précis of the impacts of such drivers as land clearing, forestry, fire, and the establishment of human infrastructure. The authors also discuss how these drivers often interact – which is a major problem as the number of threats to which a species is exposed is a key driver of eroded resilience to decline in populations of vertebrates globally. It is highlighted why understanding the drivers of marsupial decline is important, especially as it informs how conservation efforts can be targeted to limit declines. This chapter is concluded with commentary on what is needed to mitigate the effects of habitat loss and habitat fragmentation on marsupials. These include better legislation, greater funding to tackle drivers of species decline, and more long-term monitoring to quantify temporal trends in marsupial populations (including the effectiveness of management interventions to recover species).