Crows are thought to be among our most intelligent birds, and the success of the American Crow in adapting to civilization would seem to confirm this. Despite past attempts to exterminate them, crows are more common than ever in farmlands, towns, and even cities, and their distinctive caw! is a familiar sound over much of the continent. Sociable, especially when not nesting, crows may gather in communal roosts on winter nights, sometimes with thousands or even tens of thousands roosting in one grove.