Social learning can reduce the costs associated with trial-and-error learning. There is speculation that social learning could contribute to trap and bait avoidance in invasive species like the common brushtail possum (Trichosurus vulpecula)-a marsupial for which social learning has not previously been investigated. In large outdoor pens, we presented wild-caught 'demonstrator' possums with puzzle devices containing an attractive food reward; 2 of 8 demonstrators accessed the reward the first night the puzzle was presented and another three succeeded on later nights. Meanwhile, 'observer' possums in adjacent pens watched the demonstrators for five nights and then were given the opportunity to solve the puzzle themselves; 15 of 15 succeeded on their first night (a highly significant improvement). This experiment thus provides strong evidence of social learning by common brushtail possums. Future research should investigate whether information about aversive stimuli (such as traps and toxic baits) can similarly be transmitted between possums by social learning; if so, this could have important implications for possum pest control.
Keywords: Trichosurus vulpecula; common brushtail possum; eradication; social learning; vertebrate pest.