Nutritional Properties of Some Fruits Eaten by the Possum Trichosurus vulpecula in a New Zealand Broadleaf-Podocarp Forest

Previous studies have shown fruits of native plants to be an important part of the diet of the possum (Trichosurus vulpecula Kerr) in the broadleaf-podocarp forest of Oron- gorongo Valley, New Zealand. Fruits from six species of native plants, abundant in the valley in late summer and autumn, 1979, were analysed physically and chemically and compared with the leaf-only portion of the possum diet. These fruits were generally moist, rich in available carbohydrate and low in fibre and appeared to be a source of readily digestible energy. The fruits and dietary leaves were generally similar in levels of crude protein, lipid and ash, with the exception of pigeonwood fruit which was very high in lipid. Some physical characteristics of some fruits seemed to detract from their value as food for possums. It is hypothesised that inclusion of fruit in the natural diet permits greater rates of intake of digestible nutrients than is possible by consumption of leaves alone.
The high status of hinau (Elaeocarpus dentatus) fruit as a source of available energy supports the conclusion of a demographic study (Bell, 1981) that its abundance in autumn enhances the success of winter reproduction of possums in Orongorongo Valley.