Hi Birders:

About a dozen of you responded to my inquiry.from all over Vermont and even
California!  Thanks so much.  A great birding community we have here in
Vermont.  Pretty much everyone either knew or surmised the same thing.  That
the birds are seeing their reflection and are on territory, so they perceive
a rival and feel a need to defend.  Robins are known to do this, but
everyone can add Common Yellowthroats as birds that do this too.

  

Sue Elliott sent some helpful information at the Cornell Lab of Ornithology
site:

 

http://www.allaboutbirds.org/NetCommunity/Page.aspx?pid=1098#q-a-bird-keeps-
1

 

The Common Yellowthroat is at it again this morning, and he is at a window
that it is pretty hard to make non reflective, but he is not hitting it
hard, and it is only in the mornings so I think he will be fine and we will
be too!

Thanks again.

Jeannie

Two Dog Mountain

Fayston