We had the same thing happen here in the S & B for three years. The bird in our case was a robin. We have film on our windows and it reflects the sun in the morning and evening. In the morning our buddy robin would start attacking the master bath just before sunrise and continue for about two hours. He would fly into the window trying to drive off the invading other robin which was actually himself. I finally just opened the window slightly and the reflection would change and the robin would finally fly off thinking he scared his opponent off!
While out at a campground several years ago we had bird attach on of the side mirrors because it saw itself in it and thought it was competition in his area. Finally gave up but he sure did make a mess of the side of the truck!
