Dominant and subordinate behaviour of captive brushtail possums (Trichosurus vulpecula)

Brushtail possums are generally solitary animals. They use a range of olfac tory, auditory, visual, and tactile behaviour to achieve spacing between in dividuals and to establish dominance hierarchies. Existing descriptions of possum behaviour are either not widely available or incomplete, and the fun ction of dominance hierarchies is unclear. Data presented here were collect ed incidentally during observations of captive possums to determine the eff ects on dominance status of suppression of reproduction for biological cont rol. Dominant and subordinate behaviour are described and reviewed. The top -ranking possums in dominance hierarchies were always females. Dominant pos sums displaced subordinates from food, water, and dens. In our captive sett ing, only dominant males attempted to mate with females, but dominant and s ubordinate females produced a similar number of pouch young. In the wild, w here resources are limited, we predict that dominance behaviour should limi t the frequency and success of breeding by both subordinate males and femal es.