Western Bluebird; Petaluma, California

This is a photo of a female western bluebird perched on a limb.

This is the female of the pair of western bluebirds nesting in one of our bird boxes. She has a habit of flying to our windows and those of our neighbor. Sometimes she bumps into the window with her breast and other times stops just short of hitting the window. I understand it’s a territorial thing, in that she sees her reflection and thinks it’s a rival. She does this many, many times each day. I’m wondering if she will ever realize it’s not another bird.

Western Bluebird, Petaluma, California

This is the female of the pair of western bluebirds nesting in one of our bird boxes.  She has a habit of flying to our windows and those of our neighbor.  She stops just short of hitting the windows, but she repeats this oddity numerous times throughout the day.

Western Bluebird, Petaluma, California

Photo of a male western bluebird on a broken branch.

For several years now we’ve been fortunate to have a pair of western bluebirds use one of the nest boxes in our backyard. The female this year has a strange habit. She constantly flies into windows at our house and our neighbor’s house. She doesn’t injure herself, it’s more of a bump with her breast and then she will drop down to the small sill at the bottom of the window and then repeat the process over and over. It may be that she sees her reflection and is maybe trying to scare away what she thinks is a rival. I don’t know if this is right. That’s what I get when I google the question. Has anyone else seen a bluebird do this?  Does anyone have a different theory for why?