Augury was the practice of foretelling the future largely from the flight of birds. Many different outcomes could be predicted depending on the number, flight path, and type of birds observed at certain times of the year. It was practised mostly in the Roman Empire, where it was sanctioned by the government. Persons who practised augury were called augurs.
Many local governments in ancient Rome retained official augurs. The Tenth Doctor and Donna were opposed by such a person in Pompeii, although his visions of the future were not derived from augury itself. (TV: The Fires of Pompeii)