Evaluation of the Stag-Watching Technique for Census of Possums and Gliders in Tall Open Forest

Abstract

Stagwatching involves direct counts of nocturnal animals emerging from tree hollows at dusk. This technique is described and compared with spotlighting and trapping for census of possums and gliders in the tall open forests of the Victorian Central Highlands. Stagwatching detected Leadbeater's possum, the mountain brushtail possum, the sugar glider and the yellow-bellied glider, in greater numbers and at more sites than did spotlighting. Stagwatching was most effective for survey of Leadbeater's possum. Fine weather in spring, summer, or autumn appear to be the best time to stagwatch for this species. All other species were detected by spotlighting at a portion of sites where they were not detected by stagwatching. Underestimation of density by stagwatching was attributed to emergence of some individuals after dark. Further information on activity patterns is required before either stagwatching or spotlighting can be used to estimate the densities of most possum and glider species.