The acceptability of three types of predator baits to captive non-target animals

Abstract

The acceptability of three types of non-toxic predator baits to a variety of indigenous non-target species was determined in the laboratory. The bait-types tested were: Dried Meat Bait (DMB), Probait and two sizes of FoxOffTM baits (30 g and 60 g). The potential poisoning risk, if the baits had been toxic, was calculated for each species from their consumption of non-toxic bait and their sensitivity to 1080. Three species consistently sampled baits; Dasyurus geoffroii, Trichosurus vulpecula and Rattus fuscipes. Where species have had exposure to fluoroacetate-bearing vegetation, their consumption of bait and their level of tolerance to 1080 was such that only 2 of 15, 4 of 15, and 3 of 6 species were considered to be potentially at some risk from toxic DMBs, Probait, and FoxOffTM baits, respectively. In contrast, and mainly because of their lower tolerance to 1080, the theoretical risk for those species without evolutionary exposure to fluoroacetate-bearing vegetation was such that 6 of 12, 8 of 12, and 8 of 9 species theoretically face a high or moderate risk from 3-mg DMBs, Probait, and FoxOffTM baits, respectively. We emphasise, however, that theoretical risk does not necessarily equate to a practical risk, and these results are best used to determine which non-target species should be monitored at the population level during predator-control operations. Factors affecting the potential risk to non-target indigenous animals, and some cautions when extrapolating data from laboratory-based studies to the field situation, are discussed.