Activity and foraging efficiency of the aerial insectivorous bat Molossus molossus (Molossidae) in Brazilian Atlantic Forest

Activity outside day roosts among insectivorous bat species can vary considerably and has been linked to feeding habits.We aimed to assess time of emergence, duration of activity, and foraging efficiency in a Brazilian population of Molossus molossus.We also investigated if body mass gain was related to foraging amplitude and night length.We achieved 592 first-time captures and recaptures of 248 adult individuals.The bats were predominantly crepuscular.Average duration of activity outside roosts was 36 min.We found that individuals captured returning to their roosts were significantly heavier (mean = 0.80 g) than those upon emergence, equating to average consumption of ~22 mg/min insects during the bats' activity period.Although we only sampled the first of two periods of nightly activity for M. molossus, we show the importance of insectivorous bats for insect suppression, especially when insect abundance peaks during the summer.Further studies should focus on the potential for using bats as a biological control, given that Brazil has a globally significant agricultural economy.