Over the spring and summer there were many crows roosting in trees in our residential neighborhood. Starting in September, they would visit during the day but roost elsewhere. We found a large roosting area near a shopping mall - it had many trees and a construction site nearby. The crows seemed to really like the construction site. They would line up on the open beams. We've observed that crows always like a place where they can view from many angles, and also where they can get away easily. If we feed them near a corner or a wall they are much more cautious, probably because there are fewer escape routes. The construction site gave them an excellent unobstructed vantage point and there was very little activity there overnight. There were both American crows and fish crows present, and they seemed to mix quite fluidly.