Navigation strategy of acoustical sensing by bats.

点击翻译按钮获取中文摘要

We investigated how CF-FM bats adjust pulse direction and beam width according to prey position using 31-ch microphone array system. When the bat started terminal phase at approximately 1 m from the moth, G. pryeri sometime showed distinctive evasive flight. At the same time, the bats broadened the beam width of some emissions in both horizontal and vertical planes. When the moth starts evasive flight, tracking accuracy of echolocation by the bat would decrease compared to that during the approach phase. However, in 97% of emissions during the terminal phase, the beam width of the pulse was wider than the misalignment(target direction-pulse direction) as well as during search and approach phase. These findings indicate the bats actively adjusted their beam width to retain moving target in spatial window of echolocation at final stage of capturing.