spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online March 12, 2009
Journal of Experimental Biology 212, 1011-1020 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.024620
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JEB
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Surlykke, A.
Right arrow Articles by Moss, C. F.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Surlykke, A.
Right arrow Articles by Moss, C. F.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Acoustic scanning of natural scenes by echolocation in the big brown bat, Eptesicus fuscus

Annemarie Surlykke1, Kaushik Ghose2 and Cynthia F. Moss*2

1 Institute of Biology, University of Southern Denmark, Odense, DK-5230, Denmark
2 Department of Psychology, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA

Author for correspondence (e-mail: cmoss{at}psyc.umd.edu)

Accepted 4 December 2008

Echolocation allows bats to orient and localize prey in complete darkness. The sonar beam of the big brown bat, Eptesicus fuscus, is directional but broad enough to provide audible echo information from within a 60–90 deg. cone. This suggests that the big brown bat could interrogate a natural scene without fixating each important object separately. We tested this idea by measuring the directional aim and duration of the bat's sonar beam as it performed in a dual task, obstacle avoidance and insect capture. Bats were trained to fly through one of two openings in a fine net to take a tethered insect at variable distances behind the net. The bats sequentially scanned the edges of the net opening and the prey by centering the axis of their sonar beam with an accuracy of ~5 deg. The bats also shifted the duration of their sonar calls, revealing sequential sampling along the range axis. Changes in duration and directional aim were correlated, showing that the bat first inspected the hole, and then shifted its gaze to the more distant insect, before flying through the net opening. Contrary to expectation based on the sonar beam width, big brown bats encountering a complex environment accurately pointed and shifted their sonar gaze to sequentially inspect closely spaced objects in a manner similar to visual animals using saccades and fixations to scan a scene. The findings presented here from a specialized orientation system, echolocation, offer insights into general principles of active sensing across sensory modalities for the perception of natural scenes.

Key words: echolocation, bat, active sensing, directionality, visual scanning, scene analysis


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?

Related articles in JEB:

BATS SCAN SCENES SEQUENTIALLY
Kathryn Knight
JEB 2009 212: iii. [Full Text]  



This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
K. Knight
BATS SCAN SCENES SEQUENTIALLY
J. Exp. Biol., April 1, 2009; 212(7): iii - iii.
[Full Text] [PDF]


© The Company of Biologists Ltd 2009