Feeding Preferences of Common Brushtail Possums, Trichosurus-Vulpecula, on Seedlings of a Woodland Eucalypt

Abstract

When Eucalyptus blakelyi seedlings were placed on platforms in the canopies of mature trees, common brushtail possums, Trichosurus vulpecula, selectively browsed on seedlings that had been irrigated with a balanced nutrient solution, in preference to those that had been irrigated with tapwater. The seed from which the seedlings were grown had been collected from two isolated stands of trees on pastoral properties in the Australian Capital Territory. In one all the trees were healthy, and in the other the trees had dieback, but the possums' preference was independent of seed source. The foliage of the nutrient-irrigated seedlings contained more water, nitrogen, soluble sugar and fibre, and less tannin, starch and non-structural carbohydrates, than did that of the tapwater-irrigated plants. Its specific leaf weight was also lower. The possums browsed some foliage on tapwater-irrigated plants from the healthy seed source; this foliage contained more sugar, less tannin and less fibre than that of the less preferred plants. These data are discussed in terms of the dietary basis of feeding preferences of marsupial folivores.