Based on 1,362 radiotelemetry positions, mean home range for 10 adult black-bellied fruit bats, Melonycteris melanops (Pteropodidae), in lowland rainforest at Mount Garbuna, West New Britain Province, Papua New Guinea, was 2.3 ha ± 1.2 SD. Mean core-use area of adults was 0.5 ha ± 0.4 SD, and mean long axis of home range was 370 m ± 90 SD. Core-use areas were associated with day-roost shelters or flowering bananas. Means of home range, core-use area, and long axis across home range were significantly larger in subadults than in adults. During the day, M. melanops roosted singly under banana leaves or in subcanopy foliage, often showing extended fidelity to day-roost sites. Adults excluded other same-sex adults from feeding territories around bananas, but mixed-sex pairs overlapped strongly. During the first 2 h of the night, individual bats made 69–99 flights of 2- to 139-s duration. Cumulative flight represented 24–36% of the 2-h sampling periods.