1. Echolocating bats emit a highly directional sonar sound beam in the field by Annemarie Surlykke, Simon Boel Pedersen, and Lasse Jakobsen Proceedings B Volume 276(1658):853-860 March 7, 2009 ©2009 by The Royal Society

2. (a) The set-up with a linear horizontal array of three microphones and one microphone above the middle microphone. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society

3. (a,b) Isolation of first harmonic. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society

4. Removing interference from water reflections. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society

5. Flight path, beam direction and spectra. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society

6. Echolocation beam shape depends on frequency. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society

7. (a) Individual calls compared to average beam shape. Annemarie Surlykke et al. Proc. R. Soc. B 2009;276:853-860 ©2009 by The Royal Society