No bloody wonder: the pigeons on my balcony

I've been stunned by the tenacity and persistence of pigeons on my balcony this summer. I throw things at them, scream, squirt at them with my plant watering jug, bang coathangers on the window, even get out there and wave my arms and curse - because I've had to scrape up TONS of pigeon shit, and I don't like it at all! At best they fly away for a few minutes, watch me from a powerline, and return as soon as I'm gone. This got particularly ridiculous last week, when I was outside sitting in my black armchair, which I've had out there for months, and had pigeons flying in to land just inches from my head; they seemed quite heedless and startled that I was there. This has gone on for weeks now; today I discovered why.

They're nesting in the chair. They've brought in sticks, torn out parts of the bottom lining, and hatched a baby, who is now fully pigeon-sized, but still incapable of flight. I found him (or her), downy and huddling in terror, after tilting up my chair to investigate. I may have to surrender my balcony to the birds for the rest of the summer; I actually feel kind of bad at having fucked up their home, because I ripped out the lining of the chair before I realized that this baby is flightless. 

Jeezus, I hope I didn't scare its parents' away...