Large swallow; very local summer resident in mountains of northwest Mexico. Favors open pine-oak forest, usually with big dead pine snags and cliffs, where nests in cavities. Ranges widely in highlands and foothills, coming to drink at ponds and lakes. Usually seen as singles or small groups, which may associate with other swallows. Male blue-black overall with contrasting white belly. Female similar to several other martins, but clean white belly contrasts more strongly with dark breast.