Biosonar Discovery Timeline

The history of scientific research into biosonar is a fascinating tale of dedication and injustice, and an ideal demonstration of how the process of science eventually uncovers the truth, no matter how popular misguided ideas become. Click on the arrows for the full story.....
 

 

Lazaro Spallanzani discovers bats can orientate in complete darkness, and without the use of their eyes.
 






























1794
1790's
  Jurine and Spallanzani discover that bats cannot orientate in darkness when their hearing is disabled.
  		 
  Cuvier discredits the work of Jurine and Spallanzani, favours his own 'touch' hypothesis, and hinders scientific progress for > 100 years!
  		 
 

Hahn discounts the sense of touch as an explanation - but no-one takes any notice.
 

1908
1912
  Maxim first suggests a form of biological sonar, but gets the source of sound and the method of reception wrong.
 
 
  Donald Griffin and his supervisor J.W.Pierce first record the ultrasonic emissions of bats.
  		1938
1946
  The pioneering work of Dijkgraaf becomes known at the end of World War Two.
 		  
  Arthur McBride speculates that dolphins use biosonar.
  		1947
  Möhres discovers a completely different kind of sonar in horseshoe bats. 1951
1952
 
Kellogg & Kohler find that dolphins have ultrasonic hearing and (later) can discriminate different objects without vision.  
 
Forrest Wood makes the first recordings of ultrasonic sonar signals from dolphins		  
 


Evidence accumulates that bats use biosonar to hunt for insects.
1950's
 
Griffin & co-workers examine in detail bats hunting by sonar, and discover the search phase, the approach phase and terminal phase (feeding buzz).
1960
 
Ken Norris demonstrates sonar in dolphins, using blindfolds and mazes of obstacles.
1961
 
The first world conference on biological sonar is held
1966
 
Schnitzler discovers the mechanism of sonar used by horseshoe bats
1968
 
Bat detectors reveal the diversity and vaiability of sonar behaviour in the wild
1970's