I'd like to know why they do that!? Nice catch on your part!
Love that you caught it in the act. It's a magical thing to capture the wing span of a bird.
What a great photo, the timing was perfect.
funny....i have birds that try to do the same thing at my front windows from time to time. they'll do it over and over and over again. i'm not sure what they're thinking though! i love that you captured it so perfectly!
:) birds are funny. great shot
...I think that I have read in the past that this bird behavior has to do with a bird having territorial issues with its own reflection in the window...What a great shot for this theme!