Mechanical cacophony can drown out the whispers of moving insect prey
BOULDER, Colo. — The roar of humankind’s machines may make it hard for some bats to hear the tiny footsteps of their prey.
Bats that snatch insects off leaves and other surfaces find their targets by listening for the little rustles and scratchings of prey in motion. In the lab, pallid bats (Antrozous pallidus) took extra time to locate live insects when speakers blared noise, Jessie Bunkley of Boise State University in Idaho reported July 30 at the annual meeting of the Animal Behavior Society.
For the test, Bunkley released bats into a darkened chamber with an array of bowls. One held live mealworms, and the others offered freeze-dried mealworms, dead and silent. With no extra noise, pallid bats averaged 3.5 seconds to locate the living mealworms.
But when Bunkley played recordings of highway traffic or the noisy compressors found at gas wells, bats took 6 to 8 seconds to locate their meals. Bats