Prolonged foraging bouts of a solitary gleaning/hawking bat, Myotis evotis

Abstract

We investigated the foraging behaviour of reproductive female long-eared bats, Myotis evotis, roosting solitarily in natural habitat in the badlands of the South Saskatchewan River valley, Alberta, Canada. Myotis evotis behaved differently than other temperate-zone insectivorous species studied previously. Individuals foraged all night, every night, regardless of ambient temperature or reproductive condition, and only spent a small proportion of the night roosting (less than 10% of the time spent out of the roost). A high daily energy demand and an energetically costly mode of flight may necessitate this behaviour. The ability to both aerial-hawk and glean prey from surfaces may make night-long foraging profitable for M. evotis, and for other flying nocturnal insectivores that can glean.