Re: How does a Robin know where the worm is?

Evan,

It seems that many others have also been mystified by the robin’s ability 
to find worms.  It was once believed that the robin hunted by sound.  
However, a series of experiments done in the 60s, (F.H. Heppner, 1965, 
"Sensory mechanisms and environmental cues used by the American robin in 
locating earthworms.", Condor 67(3): 245-246) concluded that the robin finds 
it’s prey by sight - not sound.  Audubon’s Nature Encyclopedia , 1965, gives a
passionate description of robins and their behaviors.  Apparently, after it 
rains, worms rest with just the tips of their bodies showing at the mouth of 
their burrows... making them easy targets for the keen eyed robin.    

Your observation that the birds appear to cock their heads is accurate,  
although they do this to see the worms rather than to hear them.  Unlike owls or
hawks,  the robin's eyes are positioned to the side of it’s head, not in the 
front.  When the bird cocks its head to the side, it is actually looking 
down. 

 
I hope this helps to answer your question.  


Steven A Williams
biodswill@prodigy.net