You could hang an old CD on the outside of the window to break up the 
reflection and deter the birds from attacking their 'rival'.  It works 
at my house.


On Thu, Jul 1, 2010 at 7:00 AM, Jeannie Elias wrote:

> 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