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 FoxOff^TM 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 FoxOff^TM 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 FoxOff^TM 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.