We have families of crows where I work and that is where they stay. It is virtually safe from cats and anything else predatory. There are a fair number of trees for them so the habitat is ideal. However because of the nature of the place they are pretty tame and never in any rush to fly away. The oldest one we had, we called him 'Albert' had been around here for quite a number of years and he became such a personality. He was a huge clever bird with a very deep crow would walk up the steps with everyone else to get from A to B. He knew the shape of a triangle sandwich wrapper as opposed to anything else and would pluck it out of the bins. If he couldn't manage it especially in summer he would make a bee-line for the people eating their lunch under the tree and just stand there with his head cocked waiting but he knew he would get something. Standing in the bus-shelter he would land on the bin with a heavy clatter just to let you know he was there. I haven't seen him at all this year and think he may have gone to the big Rookery in the sky. But waiting for a bus at the end of the summer a big black crow landed with a thud on the bin slightly smaller but still pretty large. Perhaps it is the son of Albert, I keep watching out for him just in case.