Susceptibility of Bush Stone-curlews (Burhinus grallarius) to sodium fluoroacetate (1080) poisoning

Abstract

Although baiting for feral predators with sodium fluoroacetate (1080) benefit native fauna over much of Australia by reducing the abundance of those predators, there is a potential risk of poisoning to non-target species. Bush Stone-curlews (Burhinus grallarius) have declined over much of mainland southern Australia owing to predation by Red Foxes (Vulpes vulpes), but they have the potential to eat and be affected by 1080 baits. This paper explores the extent to which 1080-baiting programs may have an adverse effect on extant or reintroduced populations of Bush Stone-curlews. Our study used Bush Stone-curlews from a population that was not adapted to naturally occurring 1080, so our results are likely to be relevant throughout the range of the species. We determined the approximate lethal dose (ALD) of 1080 for Bush Stone-curlews to be 10–15 mg kg–1. Thus a Bush Stone-curlew weighing 700 g would need to eat between three and four baits, each containing 3 mg of 1080, to receive an ALD. In unforced trials, the Bush Stone-curlews in our study did not eat (undosed) meat or grain baits. Dying food blue did not deter Bush Stone-curlews from eating it. Thus, sole reliance on blue dyes to deter non-target species from taking baits seems unwise. Our results indicate that reintroduction programs for Bush Stone-curlew are unlikely to be affected by concurrent 1080-baiting for feral animal control.