The sonar beam pattern of a flying bat as it tracks tethered insects.
This paper describes measurements of the sonar beam pattern of flying echolocating bats, Eptesicus fuscus, performing various insect capture tasks in a large laboratory flight room. The beam pattern is deduced using the signal intensity across a linear array of microphones. The positions of the bat and insect prey are obtained by stereoscopic reconstruction from two camera views. Results are reported in the form of beam-pattern plots and estimated direction of the beam axis. The bat centers its beam axis on the selected target with a standard deviation (sigma) of 3 degrees. The experimental error is +/- 1.4 degrees. Trials conducted with two targets show that the bat consistently tracks one of the targets with its beam. These findings suggest that the axis of the bat sonar beam is a good index of selective tracking of targets, and in this respect is analogous to gaze in predominantly visual animals.
Ghose
Kaushik
K
Neuroscience and Cognitive Science Program, Department of Psychology, The University of Maryland, College Park, Maryland 20742, USA.
Moss
Cynthia F
CF
D000818:Animals; D002685:Chiroptera; D004455:Echolocation / Q000502:physiology*; D007313:Insecta; D008954:Models, Biological; D011235:Predatory Behavior; D014465:Ultrasonics