The problem is, I can keep our cats in only for so long (they like going out, and play up when they can't), plus I can't keep the many neighbourhood cats away.
Leaving it out to its fate is not an option, because the cat has already caught and killed 2 of it's siblings in a week, I don't like the thought of possibly the last Baby
this family has ending up the same way. Our cat, our responsibility.
We had to let the cats out earlier, so placed him in a carrier, indoors, in a closed room for a couple of hours, but the rest of the time he has been outside, chirping away.
We may have to bring it in for the night, the neighbourhood tough cats prowl at night, so it is more of a risk than in the day. It goes without saying that obviously it needs as little human contact as possible, I don't want it to have any kind of attachment to us, nor be reliant on us, and most certainly not have the parents abandon it.
I really like the windowsill idea, my only concern is it keep trying 'test flights' and ending up back in the situation that got it here in the first place, when we are unable to stop any kitty consequences. It is less than ideal circumstances, and in the worst case, we can at least say we tried.