The tree swallow (Tachycineta bicolor) nests in old trees with existing cavities (typically made by a woodpecker), or human-made nest boxes. The male has mostly glossy blue-green upperparts, the wings and tail being blackish. The underparts and the cheek patch are white. The tree swallow breeds in the US and Canada. It winters along southern US coasts south, along the Gulf Coast, to Panama and the northwestern coast of South America, and in the West Indies.