A bat that navigates using sound

Egyptian fruit bats use echolocation during daylight hours even though they have good eyesight, according to a study by a team of researchers at Tel Aviv University. In their paper published in the journal Current Biology, the group suggests explanations for the odd behaviour of fruit bats.

Most bats are nocturnal. Bats that are active during the day are rare; just 10 out of 1,400 species are diurnal. Those that are active during the day use echolocation during low light, such as at dawn or dusk. The researchers found a picture of an Egyptian fruit bat that appeared to be using echolocation during daylight hours.

The bats were roosting in the ceiling of an underground parking garage. The researchers used cameras and acoustic recording equipment to record the bats as they left the roost and became active. They found that 70% of the bats began using echolocation as they emerged from their roost. Some of the bats were even echolocating while carrying food in their mouths, which is difficult, as they use tongues to make echolocation sounds.

Phys.org