Songbird audiograms

[<>]

  Thank you Dr. or Mr. Stoker for pointing out Bob Dooling's extensive research 
(much of which is on budgerigars, to be sure) and other important points. The 
literature on this topic is not thin or hard to find.
  I would like to add that there are species of nearctic/neotropical Dendroica 
warblers whose songs extend above 6 and even above 9 or 10 kHz, as can be 
readily seen in the classic Robbins et al. guide published by Golden Books. 
These are different species from those in question, of course, but they 
certainly are songbirds. The target listeners are probably conspecifics. 
Ron Larkin