The role of non-toxic prefeed and postfeed in the development and maintenance of 1080 bait shyness in captive brushtail possums

doi:10.1071/WR98029

The role of non-toxic prefeed and postfeed in the development and maintenance of 1080 bait shyness in captive brushtail possums

J. G. Ross, G. J. Hickling, D. R. Morgan and C. T. Eason

Wildlife Research 27(1) 69 - 74
Published: 2000

Abstract

Shyness to sodium monofluoroacetate (1080) in cereal bait can persist in sub-lethally poisoned possum (Trichosurus vulpecula) populations for at least 2 years. We investigated the use of non-toxic cereal ‘prefeed’ and ‘postfeed’ as ways of inhibiting and overcoming such shyness. The postfeed result was also compared with changing to a non-cereal, gel-based 1080 bait. Prefeeding had a significant effect on the number of possums that became ‘bait shy’ following an approximate LD₂₀ 1080 dose, with 97% of non-prefed possums developing an aversion to 1080 cereal bait compared with only 22% of prefed possums. In contrast, postfeeding with cereal was relatively ineffective in reducing the number of 1080 bait-shy possums, with mortality of these possums being 30% compared with 0% of non-postfed possums. In contrast, the gel 1080 bait killed 64% of 1080 cereal bait-shy possums. These results suggest that 1080 bait shyness can be markedly reduced by prefeeding non-toxic bait to possums prior to each control operation. However, this may not be the most cost-effective control option, given the observed efficacy of follow-up baiting with 1080 gel.