Survival histories of marsupial carnivores on Australian continental shelf islands highlight climate change and Europeans as likely extirpation factors: implications for island predator restoration

Abstract

Predators are critical components of ecosystems, but large marsupial carnivores have suffered major declines and extinctions in Australia. To inform predator restoration efforts on Kangaroo Island (South Australia) we examined the survival histories and potential extirpation factors of large marsupial carnivores that previously occurred on Kangaroo Island, King Island and Flinders Island, located off the southern coastline of the Australian mainland. Through a review of historical accounts and fossil evidence, we determined that the pattern of species persistence and extirpation on Kangaroo Island parallels that observed on King and Flinders Islands. Fossil data supports the terminal Pleistocene–early Holocene extinction of the thylacine (Thylacinus cynocephalus) from Kangaroo Island and the Tasmanian devil (Sarcophilus harrisii) from both Kangaroo and Flinders Islands. Though eastern quoll (Dasyurus viverrinus) fossils have been found on both Kangaroo and Flinders Islands, and western quoll (D. geoffroii) on Kangaroo Island, contemporary evidence for their post-European persistence is unclear. In contrast, fossil, museum and anecdotal data supports the presence of the spotted-tailed quoll (D. maculatus) on all three islands and, contrary to established knowledge, its post-European persistence on Kangaroo Island. The loss of T. cynocephalus, S. harrisii, D. geoffroii and D. viverrinus from these islands appears to be commensurate with late to terminal Pleistocene–early Holocene climate change and associated changes in vegetation communities. In contrast, anthropogenic persecution of D. maculatus appears to be the principal cause of its post-European extirpation. We recommend D. maculatus as a suitable candidate marsupial carnivore for reintroduction to Kangaroo Island.