North Queensland Naturalist

Abstract

Emergence of nocturnal animals at dusk from daytime shelters may be influenced by caution with regard to predators as well as by foraging opportunity and weather. Yellow-bellied Gliders (Petaurus australis) are a nocturnal, arboreal marsupial that, in north Queensland, den in hollows predominantly in large Rose Gums (Eucalyptus grandis). We document emergence on 83 evenings in the Tumoulin and Gilbey Forests between Ravenshoe and Herberton. Dens were high in Rose Gums, twelve from a lateral spout and, unusually, one from a hole in the trunk. The first glider to emerge from a den did so from 22 minutes before to 31 minutes after End of Civil Twilight (the latter being 21–24 minutes after Sunset in the study area and approximating dusk), though most first emergences were from nine minutes before to eight minutes after. First emergence was not influenced by moonlight, season or den tree, but varied a little between glider groups. Groups of gliders sharing a den variously emerged in quick succession or up to eleven minutes later. We describe other behaviours associated with emergence. This tight pattern of emergence at dusk is in line with reports for the species in southern Australia, but we document for the first time a number of associated behaviours including infrequent calling from within the den.