In active listening, bats adjust their vocal cries emitting sounds of variable pitch, length, and repetition rate.
They can then determine details about their environment from the returning sounds.
- Echo with a sliding pitch indicates a moving object.
- Intensity flickers indicate a fluttering wing.
- Time delays between cry and echo indicate distance.
Image: Echolocating bats adjust their vocalizations to catch insects against a changing environmental background. (Photo: © Chanut F 2006)
Read about this story: The Sound of Dinner (Chanut F (2006) The Sound of Dinner. PLoS Biol 4(4): e107)