Southern blossom bats, Syconycteris australis (Pteropodidae), were followed by radiotelemetry in lowland rainforest in Kau Wildlife Area, Madang Province, Papua New Guinea. Eleven individuals were monitored ≤31 days. Based on 706 radiotelemetry positions, home ranges of 11 bats were 2.7–13.6 ha. There were no significant differences in home-range sizes between sex or age classes, but there was individual overlap of the home ranges of these bats. Long axes of home ranges were 263–725 m. During each night, bats visited most parts of their home ranges; however, activity was concentrated in core-use areas representing 19–33% of the home range and containing ≥1 food patches. During the day, S. australis roosted in the foliage of trees. Bats showed fidelity to a day-roost area (0.4–10.8% of home range) but not to a single roost tree. Day-roost areas monitored within a given year showed virtually no overlap.