Moss research uncovers bats' systematic 'active sensing' strategies
Active Control of Acoustic Field-of-View in a Biosonar System appears in the Sept. 13 edition of PLoS Biology.
The research uncovered systematic active-sensing strategies used by echolocating bats to scan their environment. The researchers trained Egyptian fruit bats to land on a target, under conditions of varying levels of environmental complexity, and measured their echolocation and flight behavior. The bats modulated the intensity of their biosonar emissions, and the spatial region they sampled, in a task-dependant manner.
The bats selectively changed the emission intensity and the angle between the beam axes of sequentially emitted clicks, according to the distance to the target, and depending on the level of environmental complexity. In so doing, they effectively adjusted the spatial sector sampled by a pair of clicksthe field-of-view.
The results suggest that lingual echolocation (based on tongue clicks) is much more sophisticated than previously believed, and reveal a new parameter under active control in animal sonarthe angle between consecutive beams. The findings suggest that acoustic scanning of space by mammals is highly flexible and modulated much more selectively than previously recognized.
September 22, 2011