...they see their reflection in the window and think it is another jay moving in on their territory. I have a redbird that constantly attacks my window for this reason. To alleviate the situation, I just put a piece of foil over the window. Voila! It stopped immediately.

i don't think that is the case here, bec. the level where they are screaming is at th eopen window, with a screen, so no reflection.

I'm starting to take this very personally!

btw, when I had a red corolla there was a redbird, whenever I parked at my community garden which is in a woods setting - he would perch on my mirror, and poop.

never on anyone else's care. Just my red Toyota.

A few years ago my Mother in Law had a bluebird house on a post in the yard. One day a blue bird kept gently running into the window by her chair. She looked out several time to see the bluebird making a fuss and mostly ignored it. After several hours she went outside and saw that the door on the bluebird house had come open and the nest was exposed. She fixed the door and the bluebird seemed to be happy and stopped it's strange behavior. Birds can be pretty smart sometimes.

Maybe if you get a chance when they're not around, check the bush (gently...) to see if they've nested there, or if there's anything weird in the bush?

There is a dead branch that extends directly toward our bedroom window. It's three floors up at the back of the house. There is also a nest about 4 feet higher in the tree, which I assumed was the bird's nest.

Each morning a bluejay (or two, sometimes) would land on the branch and shriek like crazy, very loud. Then jump off the branch, but always swooping down in the same direction, never saw them go to the nest. One day, before the leaves were full on the trees, I was able spot where they were going...thier nest was about 20 feet away, about one floor below us.

One Bluejay would stand on the branch by the nest and shriek while down below another was apparently tending to their real nest. The Jay outside our window appeared to be standing guard outside what we found out was a squirrel nest. When one bird would leave the Bluejay nest, the "guard" bird would fly down and take it's place, then come back and shriek at the squirrel nest as the other returned to tend to their babies (or eggs). The whole exercise seemed to be to warn the squirrel to keep away.

I know I've seen birds lead predators away from the nest.

That being said, maybe their nest is nearby and they are being protective. Every year we have a robin nest under our deck and they are less than happy when we walk around it near their nest.

This will stop in a week or two.

they chose to build near me.

I hope all the little ones survive and thrive, even if bluejays are the bullies of the bird world.

when we lived in MN and a blue jay built a nest in our yard. All summer, that blue jay would chase that dog all over the yard. The dog was crazy scared of that bird.

had a black cat. The birds would divebomb my poor kitty for her fur for their nest, but would never bother the other cat.
I don't know if it was a decorating choice, or if the other cat was bolder.
My cat wouldn't even go out when those birds were around.

My balcony snugged up to an enormous tree, which was wonderful for shade and privacy, but during nesting season there was always a blue jay going completely apeshit on me every time I went out to read. Eventually they'd stop and I'd get my balcony back for the rest of the year.