Mammals
Big Brown Bat
Eptesicus fuscus · also called big brown bats
Tucked into the eaves of an old barn at dawn, a big brown bat settles in to roost after a night spent crushing hard-shelled beetles with a bite stronger than many of its smaller, more delicate bat relatives could manage.
Overview
The big brown bat, Eptesicus fuscus, is a hardy, adaptable insect-eating mammal native to forest and grassland habitat across a broad range of North America. Its unusual resistance to white-nose syndrome, comfort roosting in human structures, and powerful bite suited to hard-shelled prey make it one of the more resilient and commonly encountered bats found across the continent.
A survivor among a struggling family
While white-nose syndrome has devastated many smaller North American bat species in recent decades, the big brown bat has proven notably more resistant, a resilience that has kept its populations comparatively stable even as close relatives have suffered severe declines.
Status
Least Concern, widespread and stable across suitable forest and grassland habitat throughout most of North America, showing considerably more resilience to white-nose syndrome than several smaller bat relatives.
Big Brown Bat: common questions
Why has the big brown bat fared better against white-nose syndrome than other bats?
This species has shown considerably more resistance to white-nose syndrome than several smaller bat relatives, a difference researchers attribute partly to its larger size and hardier physiology, helping its populations remain comparatively more stable even in areas where the disease has devastated other bat species.
Where does the big brown bat like to roost?
This species readily roosts in human structures such as attics, barns, and bridges, in addition to natural sites like caves, hollow trees, and rock crevices, a flexibility that makes it one of the more commonly encountered bats in areas close to people.
What makes the big brown bat's bite unusual among bats?
This species has a comparatively strong bite and skull structure well suited to crushing the hard exoskeletons of beetles, giving it access to a food source that bat species with weaker jaws are less able to exploit effectively.
Where does the big brown bat spend the winter?
This species hibernates through the winter in caves, mines, or occasionally buildings, seeking out cold, stable locations that allow it to conserve energy until insect prey becomes available again with the arrival of spring.