Thanks for asking about the little bird. It is doing great, not least due to my tender care.
This was on day 2, already looking a bit more like a bird than it did before:
I have been feeding them seeds and put up a bowl of water. The bird family appreciates both very much. I refresh it only once every day, to disturb them as little as possible. Over the time, I have noticed that the pigeon realizes that I pose no danger and that she has become far less shy. I wonder how my support will shape the little bird’s opinion of humans. It might be hard for it to reconcile conventional bird teaching with his positive experience on my balcony.
This last photo shows day 5 in the life of the chick:
If I ever study biology or zoology, I should get academic credit for this.