Pigeons on the balcony

Lately, a couple of pigeons have appeared on my balcony. There’s just enough room for my folding chair and TV tray to place a cup of tea. I have a set of bookshelves out there on which I cultivate a number of potted plants. Maybe it was this semblance of a cultivated city garden which attracted them. My feelings are mixed. It’s early spring and they are looking to nest. My balcony faces south, it is sheltered from the wind, and it was undisturbed for a week when I was in France. But now I am back and I want to plant some herbs, sit out there on weekend mornings with a newspaper. There’s not enough room for the three of us. If they were there, I could not leave my tasty snacks unattended. If they had a chick in their nest, no right-minded pigeon parent would leave it while I quaffed tea and gathered herbs. So far, several days of assertive disturbance seem to have off the pigeons. As of yet, I haven’t resorted to a fake "scare" owl. Whether or not those work, I wonder.