As has already been suggested it be best for the little cat to be kept indoors for a while. Our youngest cat is also about a year old and his pregnant mother was left behind when her owners moved, luckily the new mum and her kittens were found by a neighbour and taken to PDSA and one of them to us. He was very very timid and nervous at first (we have 4 other cats) but he settled eventually, and though still very nervous he is getting much better, it will take a lot of time until he settles, best to keep him/her away from the bullying neighbour cats for a while. On the plus side, a suicidal mouse (had to be to come into a house with 5 cats) was caught by our little, very timid cat a few weeks back, he's the last one I would have thought to be a mouser. Lots of patience and love required I think