Functional daylight echolocation in highly visual bats.

Bats rely on echolocation for operating in dim light or dark conditions. Accordingly, most research on echolocation is performed under dark conditions with a few exceptions. Bat species that emerge to forage before sunset have been shown to use echolocation even in relatively high light levels. It has been argued that for insectivorous bats, as light levels decrease, echolocation rapidly becomes advantageous over vision for detecting tiny insects during dusk or dawn and that information from the two sensory modalities is integrated. Functional use of echolocation in broad daylight in insectivorous bats has been scarcely reported. Here, we report functional use of echolocation in broad daylight in highly visual fruit bats.