Question: This cowbird comes to the pole that the hummingbird feeder is on several times a day. It faces the window and fans its wings out flapping, a courtship display, maybe? I am a little concerned that it will keep the hummers away. Any thoughts? – Patricia Schaefer
Answer: This is a Brown-headed Cowbird doing a territorial display. Brown-headed Cowbirds are promiscuous, but they also fight for the right to mate. It is not uncommon for a group of males to do a performance directed at the other male. The performance usually consists of a back feather ruffle, a head bow with a wing lift. It often ends with a bill wipe.
Since your bird is facing the window, it is seeing its reflection and thinks it is another bird. In a normal situation, one of the birds would back down, giving a submissive display. Since your window is acting like a mirror, the “second” bird never backs down. It is possible this display will lead to this bird “attacking” your window in an effort to drive away the intruder.
Undoubtedly, the hummingbirds will avoid the area during the display period. They will come back when the cowbird moves on. To discourage the cowbird, putting something in the window that breaks up the reflection might help.
Answer by: Robert Mercer
SIB 
We did as you suggested and placed newspaper over the window by the hummingbird pole. He quickly moved to a new spot on our deck, looking in the window and dancing with himself! We pulled other furniture away and he always goes to the same perch-an item on a table in front of a window. It has almost been a month now and he is here every day, most of the day, admiring himself in the window. We call him Donald.
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