The other day I was at Jug Bay in AACo.  There were LOTS of red-wigned black 
birds feasting on the wild rice patches.  What struck me as funny was the 
sheer numbers of males(mostly) that were missing their tail feathers 
completely or were in the process of growing them back.  I know that some 
bird groups (ducks) can loose all of their flight feathers at once, but I 
didn't know any passerines did that.  It was just weird seeing these black 
balls flying around with red and yellow racing stripes.

Does anyone have any idea why so many birds all at once would seem to have 
lost the same feathers?

Adam Smith

Baltimore County MD
Anne Arundel County MD