Trophic ecology of marsupial predators in arid Australia following reshaping of predator assemblages

Abstract

The extirpation of marsupial predators and their replacement by eutherian carnivores are likely to have cascading ecological impacts on the trophic structure of arid Australia. Here, we assessed the diet and characterized the trophic role of the 3 largest remaining carnivorous marsupials (< 200 g body mass) in arid Australia: crest-tailed mulgaras (Dasycercus cristicauda), kowaris (Dasyuroides byrnei), and brush-tailed mulgaras (Dasycercus blythi). The species show a high level of trophic connectivity; each is highly interactive, being predator or prey of numerous species across multiple phyla. The prey base of each of the predator species was broad and included vertebrates, invertebrates, and plants. Crest-tailed mulgaras consumed the most vertebrates including prey up to the size of the southern marsupial mole (Notoryctes typhlops). Kowaris consumed prey up to the size of the European rabbit (Oryctolagus cuniculus). Although capable of capturing or scavenging vertebrates, the diet of each species was dominated by arthropods < 2 g in body mass.