Do brushtail possums (Trichosurus vulpecula) show preferences for exogenous odours associated with food?

Abstract

The brushtail possum is the major vertebrate pest in New Zealand, and during control operations a variety of odours are used to lure possums to traps and poison baits. Paired tests were performed in large outdoor enclosures to determine if the preferences of possums for these odours differed. In Experiment 1, we tested the preferences of six possums for orange, cinnamon, cloves, peanut and almond odours. The subjects showed no significant preference for any of the odours, and no one was preferred more than water. In Experiment 2, we tested the preferences of the same six possums for the synthetic odour of the plant Dactylanthus taylorii, which appears to be highly attractive to wild possums in New Zealand. Preferences for the synthetic Dactylanthus odour were determined relative to an odour the possums were familiar with (orange) and a novel odour (peppermint). There were no significant differences between the responses shown by the possums to the three odours. Possums may have shown little preference for these odours because they were either unfamiliar (the distribution of Dactylanthus has become restricted in New Zealand) or were not associated with a food. These results suggest that a positive post‐ingestive experience is important for the formation of odour preferences. © The Royal Society of New Zealand 2000.