Torpor patterns in food-deprived Myotis lucifugus (Chiroptera: Vespertilionidae) under simulated roost conditions

Temperate insectivorous bats are commonly prevented from foraging by cold or wet weather. This study examines the effect of missing a single night of foraging on the energetics of pregnant and lactating little brown bats (Myotis lucifugus) under simulated roost conditions. After not foraging, the day-roosting metabolic rate of pregnant M. lucifugus was reduced by 61% and that of lactating bats by 46%. Although previous laboratory studies predicted that food-deprived bats should remain in torpor throughout the day-roosting period, M. lucifugus consistently aroused from torpor between 11:00 and 15:00 and maintained elevated metabolic rates for the rest of the day.