Susceptibility of the golden bandicoot to the toxic Eradicat bait

Abstract Context: The suppression of feral cat populations is critical to the successful conservation of native fauna in Australia. The aerial distribution of Eradicat® baits with 4.5 mg of sodium monofluoroacetate (1080), at a rate of 50 baits km-2 demonstrably reduces feral cat populations. One of the five native marsupials that have been reintroduced to the Matuwa Kurrara Kurrara National Park (MKKNP), the golden bandicoot (Isoodon auratus) is thought to be at some risk from 1080 baits due to an omnivorous diet, small body size (260-650 g), and LD50 of 8.94 mg/kg. Aims: Our aim was to test the susceptibility of golden bandicoots to the Eradicat® bait under the common field application protocol. Methods: We used 20 Holohil RI-2D VHF collars and 20 Holohil PD-2 subcutaneous VHF transmitters, on 40 bandicoots (34 male and 6 female) and nine 10 m stationary towers, each with two 4 element yagi antennas, connected to a Nooelec NESDR SMArt SDR VHF receiver and Raspberry Pi 3 running SDR Tracking Version 4.1 paur, to track the survival of individual animals. We hand-laid 200 Eradicat® baits which also contained the dye, Rhodamark, in the south-west corner of a fenced introduced predator-free enclosure on MKKNP. Key results: 11% (4/38) of bandicoots showed signs of having consumed a sub-lethal amount of bait, and 3% (1/38) consumed a lethal dose. Two RI-2D VHF collars were shed by bandicoots with no further information on the fate of the animals collected. Conclusions: We conclude golden bandicoots are at minimal risk from 1080 baiting regimes. Implications: Under a risk-benefit framework this implies that golden bandicoots have more to gain from the suppression of feral cats via the use of Eradicat® baits than they risk through direct exposure to the baits. We recommend cautious consideration of this conclusion as results are from a single study.