On Tue, 14 Jun 2011 17:34:40 +0200, "ViLco" > wrote:

>Dora wrote:
>
>>> I guess at that time in the morning the light is such that the
>>> windows
>>> act as mirrors. The bird is probably trying to drive off a rival but
>>> it takes him 20 or more thumps to get the point or perhaps knock
>>> himself even stupider.....BIRD BRAIN!
>
>> Yes, we had a low IQ male cardinal who used to do the same thing -
>> attacking his rival in the window, morning after morning.
>
>Here it was a male blackbird, he too went on for a score times, and it
>lasted for a week and some more

We had a pair of wild turkeys preening and courting right outside my
office window last year. The female divided her coy looks and
responses quite equally between the male and his reflection on the
black glass of the building.

Boron