My parent's house is out in the woods at the top of a hill. They;ve got 6 or 7 different bird feeders. They get everything from sparrows, to hawks, bald eagles, and turkey vultures (circling overhead on thermals), all sorts of woodpeckers, including Pillieated (AKA woody woodpecker)
It's always fun to head out there, sit on the deck and watch the huge variety of birds that flit in and out of the area.
Squirrels get into the feeders and make huge messes - so action is taken. I swear Squirrels recognize the pellet gun when they see it. When that doesnt suffice, the dog manages to tree quite a few of em.
Nothing against squirrels, but they do make a mess, and make the birds more shy.