Feeding Behaviour and Food Availability of the Yellow-Bellied Glider in North Queensland.

Abstract

The diet of the yellow-bellied glider (Petaurus australis) was examined at a site in north Queensland by extensive observation of individuals from 10 glider groups. The diet was assessed in four seasons over 12 months by collating large numbers of qualitative feeding observations and by analysis of faeces. Data were also collected on flowering and bark shedding in the forest. Sap feeding accounted for more than 80% of the feeding observations throughout the year. Nectar and pollen of eucalypts (Eucalyptus spp.) and banksias (Banksia spp.) accounted for much of the remainder of the diet although arthropods and honeydew were present in spring and summer. Faecal analysis was based on much smaller sample sizes but confirmed the qualitative result obtained from direct observations. It also revealed the presence of a wide variety of pollen types. Many of these could be attributed to incidental ingestion but at least six rain forest genera were moderately common in faeces, which is consistent with observations of brief and infrequent visits by gliders to these trees. Examination of eucalypt, banksia and other pollen types showed that 60-70% of pollen was devoid of cell contents, supporting earlier suggestions that gliders obtained protein from pollen digestion, but at this site also from harvesting arthropods. This study confirms the dependence of the yellow-bellied glider in north Queensland on the sap of the red stringybark (Eucalyptus resinifera) and that conservation of the yellow-bellied glider is intimately associated with the management of this tree species. The use of various species for nectar and pollen suggests that the yellow-bellied glider may be an important pollinator in these forests. Moreover, sap from the wounds created by gliders is used by a range of other animal species. These observations suggest that the yellow-bellied glider is likely to be a keystone species in the open-forest ecosystems of north Queensland and that it deserves special emphasis in management.