Roosting requirements and movements between foraging areas and roost sites were studied in four species of bats found in Tasmania, Eptesicus regulus, E. sagittula, Chalinolobus morio and Nyctophilus geofroyi, in an area of regrowth forest surrounded by mature eucalypt forest. Movements between traps and roost sites were normally about 1 km, with the maximum distance recorded being 4.8 km for a female N. geoffroyi. Different species of eucalypts were used as roost sites in proportion to their occurrence in the forest. However, large trees over 80 cm in diameter at breast height were favoured. There was no tendency to avoid roost sites close to the ground. Spaces used as roost sites had one dimension little greater than the bat itself. Five types of roost sites were distinguished: in fissures, inside burnt out boles, in hollows, under bark, and on the ground. Individuals changed roost sites frequently but roosts used by any one individual were in the same general vicinity. The factors associated with production of roost sites in trees were: large size, overmaturity, death, rot, and fire. No bats were found to roost in regrowth forest. Patches of mature forest will need to be retained to ensure a shortage of roosts does not occur as more areas of mature forest are converted to production forest.

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