(Uploaded by Plazi for the Bat Literature Project) Habitat use and nocturnal activity patterns of the threatened lesser short-tailed bat (Mystacina tuberculata) were sampled during late spring and early summer using automatic bat detector units in temperate beech (Nothofagus) rainforest in Fiordland, New Zealand. Detector units recorded the number of bats passing per hour as an index of activity. Habitat use patterns were compared with longtailed bats (Chalinolobus tuberculatus) sampled concurrently. Activity levels in lesser short-tailed bats varied significantly among five habitat types and amongst hours of the night. Of the total activity recorded, most passes (82.6% of n = 657 bat passes) were in red beech forest >200 m from the forest edge; 13.7% were in silver beech within 100 m of forest edges, 2.6% were along roads through forest, 0.9% were on the forest-grassland edge, and 0.2% were in the open grassland. Lesser short-tailed bats were active throughout the night but especially at dawn and dusk. There was no correlation between levels of activity by lesser short-tailed bats and overnight minimum or dusk temperatures. Patterns of habitat use and activity in long-tailed bats were significantly different from those of lesser short-tailed bats.