My balcony has become a pigeon "resort" and I'm just not that hospitable...?

In the coldest months of the winter, I noticed that a pigeon had layed 2 eggs on my 11th floor balcony - overlooking Lake Erie. Admittedly, it was an interesting family arrangement. 4 birds actually sat on the eggs - a coal black one, a pure white one, one of the typical grey/white one, and one that was the most beautiful aqua you've ever seen. Well, I've not seen birds have babies since I was a little girl and how would I turn them out (and where??) in 0 degree weather? I knew eventually new life would hatch through, learn to fly and the entire group of surrogate mothers and babies would be gone forever. Now, they had made their "nest" out of very petite 6" twigs in a pot of soil that had been left on the balcony after gardening season was over - just like I've done for 5 years - but this was the first time I'd found myself monitoring a true nursery. True to form, the eggs hatched, actually quite adorable birds were born, they grew healthy and strong (who wouldn't with 4 mommies feeding them) and FINALLY they learned to fly and were gone. NOW, here's the problem - the pigeons (adults) just keep coming back every day, 4-5 times a day and I don't want the problems they bring with them. Can someone give me a DIY humane answer to my DIM (did it myself) charity?