Jeannie and others,
Another good thing to do is to check Cornell's web site all about birds: http://www.allaboutbirds.org/NetCommunity/Page.aspx?pid=1184
 
If you follow this link they explain what is happening at your house and various alternatives to protect birds from window collisions.
this spring we watched a robin at a relatives house do the same thing. It is disturbing but probably will not harm the bird.
Marv 

Marvin Elliott
Rutland County Audubon Society
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--- On Thu, 7/1/10, Jeannie Elias <[log in to unmask]> wrote:


From: Jeannie Elias <[log in to unmask]>
Subject: [VTBIRD] Odd Bird Behavior
To: [log in to unmask]
Date: Thursday, July 1, 2010, 7:00 AM


Once this spring and now this summer I witnessed odd bird behavior that I am
not sure what to think about.  It involves a bird precariously perching on
or near a window frame and then flying continually at the window panes
themselves, as if it is trying to get in.  This Spring I saw an American
Robin do it.  Over and over and over again.from perches right on the
frame..and from perches a few inches away, tapping against the second story
window.  There were plants inside on the window sill.  So first I shut off
the lights, no change.  Then I moved the plants out of sight, no change.
Finally I put a towel inside the window frame and the behavior ceased.  This
morning a Male Common Yellowthroat is doing the exact same thing, at a
different window, this one on the first floor.  It has been going on for at
least 20 minutes, and since my husband saw the bird on a nearby post over
the past few days, I wonder if it has been going on for that length of time.

Any ideas on what this behavior is and whether I should be worried for the
bird?

Thanks.

Jeannie