We love the Eastern bluebird and have several houses for them. Bluebirds are beneficial as they not only are pretty and pleasant to hear, they also eat bugs. We have them around all year long.
One problem we have though, the males are territorial and they will fight their reflection. In the mornings we found bird poop all over the rear view mirror and streaks of white poop down the side of the car which had to be washed off.
To discourage this, we put a rubber snake of each vehicle. This stopped them immediately. No more bird poop to deal with. It is a great scare tactic but just don't forget and drive off with it on your mirror.
we fill the bird feeders and birds rarely cause any problems.