Use of sap trees by the yellow-bellied glider in the Shoalhaven region of New South Wales

Abstract

This study examined the use of sap trees by yellow-bellied gliders (Petaurus australis) at 33 sites scattered through approximately 10 000 ha of forest. In all, 62 grey gum (Eucalyptus punctata) trees were assessed during seven visits over a 2-year period for use by gliders in sap feeding (either currently or during the previous month). About 40% of trees had been used prior to each visit, indicating a very high pattern of use. About 29% of trees were used prior to many visits while 18% were not used at all. Gliders made small incisions on trees, apparently to test their suitability for sap feeding. These test incisions were seen several times on all the sap trees that remained unused during this study. They were made on about 60% of trees that were not used for sap feeding within the month prior to a visit. At 23 of the 33 sites, test incisions were also observed on E. punctata non-sap trees. These observations show that gliders actively check sap trees and non-sap trees. This study confirms the importance of sap trees to the yellow-bellied glider and highlights the need for further research that aims to identify the key parameters of these trees to which gliders respond. This would greatly facilitate the management and conservation of the yellow-bellied glider.