After the breeding season, American crows begin to gather in small, communal roosts. By early to mid-winter the number of crows occupying a roost reaches its maximum. In the morning, shortly before and after daybreak, crows leave their nocturnal roosts in small groups and fly in all directions leading to feeding grounds. After having spent the day feeding, roughly two to three hours before sunset, small groups of crows gather in pre-roost sites, and from these fly along regular flight lines towards their roost. They are often joined by additional crows at pre-roost sites visited along the way. The closer the crows get to their final roost, the larger the group becomes. The same roosting sites may be used for many years and the number of birds in them varies from a few hundred to many thousands.