In our previous house we had a cypress tree in our garden where pigeons regularly nested. As Tegan said, the young don't put in an appearance until they are almost fledged, when they will sit on an exposed branch, flap about exercising their wings and being fed by the parents. We occasionally had an unfledged baby fall out of the nest. They are a nuisance though; they make a horrible mess of our conservatory roof and are greedy feeders. They are, however, very entertaining to watch when they are courting, going from the pursuit to the copulation and then the very tender preening sessions that follow! We watched all this one evening a couple of weeks ago going on on a roof opposite our house. While all this was going on, a magpie sat at the other end of the ridge watching. I wondered if this was the bird equivalent of "dogging". When they had finished, it flew away!